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Diffstat (limited to '')
| -rw-r--r-- | fs/btrfs/inode.c | 10517 |
1 files changed, 10517 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c new file mode 100644 index 000000000..c900a3966 --- /dev/null +++ b/fs/btrfs/inode.c @@ -0,0 +1,10517 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2007 Oracle. All rights reserved. + */ + +#include <crypto/hash.h> +#include <linux/kernel.h> +#include <linux/bio.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/pagemap.h> +#include <linux/highmem.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/backing-dev.h> +#include <linux/writeback.h> +#include <linux/compat.h> +#include <linux/xattr.h> +#include <linux/posix_acl.h> +#include <linux/falloc.h> +#include <linux/slab.h> +#include <linux/ratelimit.h> +#include <linux/btrfs.h> +#include <linux/blkdev.h> +#include <linux/posix_acl_xattr.h> +#include <linux/uio.h> +#include <linux/magic.h> +#include <linux/iversion.h> +#include <linux/swap.h> +#include <linux/migrate.h> +#include <linux/sched/mm.h> +#include <linux/iomap.h> +#include <asm/unaligned.h> +#include "misc.h" +#include "ctree.h" +#include "disk-io.h" +#include "transaction.h" +#include "btrfs_inode.h" +#include "print-tree.h" +#include "ordered-data.h" +#include "xattr.h" +#include "tree-log.h" +#include "volumes.h" +#include "compression.h" +#include "locking.h" +#include "free-space-cache.h" +#include "inode-map.h" +#include "props.h" +#include "qgroup.h" +#include "delalloc-space.h" +#include "block-group.h" +#include "space-info.h" + +struct btrfs_iget_args { + u64 ino; + struct btrfs_root *root; +}; + +struct btrfs_dio_data { + u64 reserve; + loff_t length; + ssize_t submitted; + struct extent_changeset *data_reserved; + bool sync; +}; + +static const struct inode_operations btrfs_dir_inode_operations; +static const struct inode_operations btrfs_symlink_inode_operations; +static const struct inode_operations btrfs_special_inode_operations; +static const struct inode_operations btrfs_file_inode_operations; +static const struct address_space_operations btrfs_aops; +static const struct file_operations btrfs_dir_file_operations; + +static struct kmem_cache *btrfs_inode_cachep; +struct kmem_cache *btrfs_trans_handle_cachep; +struct kmem_cache *btrfs_path_cachep; +struct kmem_cache *btrfs_free_space_cachep; +struct kmem_cache *btrfs_free_space_bitmap_cachep; + +static int btrfs_setsize(struct inode *inode, struct iattr *attr); +static int btrfs_truncate(struct inode *inode, bool skip_writeback); +static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent); +static noinline int cow_file_range(struct btrfs_inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written, int unlock); +static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start, + u64 len, u64 orig_start, u64 block_start, + u64 block_len, u64 orig_block_len, + u64 ram_bytes, int compress_type, + int type); + +static void __endio_write_update_ordered(struct btrfs_inode *inode, + const u64 offset, const u64 bytes, + const bool uptodate); + +/* + * Cleanup all submitted ordered extents in specified range to handle errors + * from the btrfs_run_delalloc_range() callback. + * + * NOTE: caller must ensure that when an error happens, it can not call + * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING + * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata + * to be released, which we want to happen only when finishing the ordered + * extent (btrfs_finish_ordered_io()). + */ +static inline void btrfs_cleanup_ordered_extents(struct btrfs_inode *inode, + struct page *locked_page, + u64 offset, u64 bytes) +{ + unsigned long index = offset >> PAGE_SHIFT; + unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT; + u64 page_start = page_offset(locked_page); + u64 page_end = page_start + PAGE_SIZE - 1; + + struct page *page; + + while (index <= end_index) { + page = find_get_page(inode->vfs_inode.i_mapping, index); + index++; + if (!page) + continue; + ClearPagePrivate2(page); + put_page(page); + } + + /* + * In case this page belongs to the delalloc range being instantiated + * then skip it, since the first page of a range is going to be + * properly cleaned up by the caller of run_delalloc_range + */ + if (page_start >= offset && page_end <= (offset + bytes - 1)) { + offset += PAGE_SIZE; + bytes -= PAGE_SIZE; + } + + return __endio_write_update_ordered(inode, offset, bytes, false); +} + +static int btrfs_dirty_inode(struct inode *inode); + +static int btrfs_init_inode_security(struct btrfs_trans_handle *trans, + struct inode *inode, struct inode *dir, + const struct qstr *qstr) +{ + int err; + + err = btrfs_init_acl(trans, inode, dir); + if (!err) + err = btrfs_xattr_security_init(trans, inode, dir, qstr); + return err; +} + +/* + * this does all the hard work for inserting an inline extent into + * the btree. The caller should have done a btrfs_drop_extents so that + * no overlapping inline items exist in the btree + */ +static int insert_inline_extent(struct btrfs_trans_handle *trans, + struct btrfs_path *path, int extent_inserted, + struct btrfs_root *root, struct inode *inode, + u64 start, size_t size, size_t compressed_size, + int compress_type, + struct page **compressed_pages) +{ + struct extent_buffer *leaf; + struct page *page = NULL; + char *kaddr; + unsigned long ptr; + struct btrfs_file_extent_item *ei; + int ret; + size_t cur_size = size; + unsigned long offset; + + ASSERT((compressed_size > 0 && compressed_pages) || + (compressed_size == 0 && !compressed_pages)); + + if (compressed_size && compressed_pages) + cur_size = compressed_size; + + inode_add_bytes(inode, size); + + if (!extent_inserted) { + struct btrfs_key key; + size_t datasize; + + key.objectid = btrfs_ino(BTRFS_I(inode)); + key.offset = start; + key.type = BTRFS_EXTENT_DATA_KEY; + + datasize = btrfs_file_extent_calc_inline_size(cur_size); + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, root, path, &key, + datasize); + if (ret) + goto fail; + } + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, ei, trans->transid); + btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE); + btrfs_set_file_extent_encryption(leaf, ei, 0); + btrfs_set_file_extent_other_encoding(leaf, ei, 0); + btrfs_set_file_extent_ram_bytes(leaf, ei, size); + ptr = btrfs_file_extent_inline_start(ei); + + if (compress_type != BTRFS_COMPRESS_NONE) { + struct page *cpage; + int i = 0; + while (compressed_size > 0) { + cpage = compressed_pages[i]; + cur_size = min_t(unsigned long, compressed_size, + PAGE_SIZE); + + kaddr = kmap_atomic(cpage); + write_extent_buffer(leaf, kaddr, ptr, cur_size); + kunmap_atomic(kaddr); + + i++; + ptr += cur_size; + compressed_size -= cur_size; + } + btrfs_set_file_extent_compression(leaf, ei, + compress_type); + } else { + page = find_get_page(inode->i_mapping, + start >> PAGE_SHIFT); + btrfs_set_file_extent_compression(leaf, ei, 0); + kaddr = kmap_atomic(page); + offset = offset_in_page(start); + write_extent_buffer(leaf, kaddr + offset, ptr, size); + kunmap_atomic(kaddr); + put_page(page); + } + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(path); + + /* + * We align size to sectorsize for inline extents just for simplicity + * sake. + */ + size = ALIGN(size, root->fs_info->sectorsize); + ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start, size); + if (ret) + goto fail; + + /* + * we're an inline extent, so nobody can + * extend the file past i_size without locking + * a page we already have locked. + * + * We must do any isize and inode updates + * before we unlock the pages. Otherwise we + * could end up racing with unlink. + */ + BTRFS_I(inode)->disk_i_size = inode->i_size; + ret = btrfs_update_inode(trans, root, inode); + +fail: + return ret; +} + + +/* + * conditionally insert an inline extent into the file. This + * does the checks required to make sure the data is small enough + * to fit as an inline extent. + */ +static noinline int cow_file_range_inline(struct btrfs_inode *inode, u64 start, + u64 end, size_t compressed_size, + int compress_type, + struct page **compressed_pages) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_trans_handle *trans; + u64 isize = i_size_read(&inode->vfs_inode); + u64 actual_end = min(end + 1, isize); + u64 inline_len = actual_end - start; + u64 aligned_end = ALIGN(end, fs_info->sectorsize); + u64 data_len = inline_len; + int ret; + struct btrfs_path *path; + int extent_inserted = 0; + u32 extent_item_size; + + if (compressed_size) + data_len = compressed_size; + + if (start > 0 || + actual_end > fs_info->sectorsize || + data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) || + (!compressed_size && + (actual_end & (fs_info->sectorsize - 1)) == 0) || + end + 1 < isize || + data_len > fs_info->max_inline) { + return 1; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + btrfs_free_path(path); + return PTR_ERR(trans); + } + trans->block_rsv = &inode->block_rsv; + + if (compressed_size && compressed_pages) + extent_item_size = btrfs_file_extent_calc_inline_size( + compressed_size); + else + extent_item_size = btrfs_file_extent_calc_inline_size( + inline_len); + + ret = __btrfs_drop_extents(trans, root, inode, path, start, aligned_end, + NULL, 1, 1, extent_item_size, + &extent_inserted); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + if (isize > actual_end) + inline_len = min_t(u64, isize, actual_end); + ret = insert_inline_extent(trans, path, extent_inserted, + root, &inode->vfs_inode, start, + inline_len, compressed_size, + compress_type, compressed_pages); + if (ret && ret != -ENOSPC) { + btrfs_abort_transaction(trans, ret); + goto out; + } else if (ret == -ENOSPC) { + ret = 1; + goto out; + } + + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags); + btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0); +out: + /* + * Don't forget to free the reserved space, as for inlined extent + * it won't count as data extent, free them directly here. + * And at reserve time, it's always aligned to page size, so + * just free one page here. + */ + btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE); + btrfs_free_path(path); + btrfs_end_transaction(trans); + return ret; +} + +struct async_extent { + u64 start; + u64 ram_size; + u64 compressed_size; + struct page **pages; + unsigned long nr_pages; + int compress_type; + struct list_head list; +}; + +struct async_chunk { + struct inode *inode; + struct page *locked_page; + u64 start; + u64 end; + unsigned int write_flags; + struct list_head extents; + struct cgroup_subsys_state *blkcg_css; + struct btrfs_work work; + atomic_t *pending; +}; + +struct async_cow { + /* Number of chunks in flight; must be first in the structure */ + atomic_t num_chunks; + struct async_chunk chunks[]; +}; + +static noinline int add_async_extent(struct async_chunk *cow, + u64 start, u64 ram_size, + u64 compressed_size, + struct page **pages, + unsigned long nr_pages, + int compress_type) +{ + struct async_extent *async_extent; + + async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS); + BUG_ON(!async_extent); /* -ENOMEM */ + async_extent->start = start; + async_extent->ram_size = ram_size; + async_extent->compressed_size = compressed_size; + async_extent->pages = pages; + async_extent->nr_pages = nr_pages; + async_extent->compress_type = compress_type; + list_add_tail(&async_extent->list, &cow->extents); + return 0; +} + +/* + * Check if the inode has flags compatible with compression + */ +static inline bool inode_can_compress(struct btrfs_inode *inode) +{ + if (inode->flags & BTRFS_INODE_NODATACOW || + inode->flags & BTRFS_INODE_NODATASUM) + return false; + return true; +} + +/* + * Check if the inode needs to be submitted to compression, based on mount + * options, defragmentation, properties or heuristics. + */ +static inline int inode_need_compress(struct btrfs_inode *inode, u64 start, + u64 end) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + + if (!inode_can_compress(inode)) { + WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG), + KERN_ERR "BTRFS: unexpected compression for ino %llu\n", + btrfs_ino(inode)); + return 0; + } + /* force compress */ + if (btrfs_test_opt(fs_info, FORCE_COMPRESS)) + return 1; + /* defrag ioctl */ + if (inode->defrag_compress) + return 1; + /* bad compression ratios */ + if (inode->flags & BTRFS_INODE_NOCOMPRESS) + return 0; + if (btrfs_test_opt(fs_info, COMPRESS) || + inode->flags & BTRFS_INODE_COMPRESS || + inode->prop_compress) + return btrfs_compress_heuristic(&inode->vfs_inode, start, end); + return 0; +} + +static inline void inode_should_defrag(struct btrfs_inode *inode, + u64 start, u64 end, u64 num_bytes, u64 small_write) +{ + /* If this is a small write inside eof, kick off a defrag */ + if (num_bytes < small_write && + (start > 0 || end + 1 < inode->disk_i_size)) + btrfs_add_inode_defrag(NULL, inode); +} + +/* + * we create compressed extents in two phases. The first + * phase compresses a range of pages that have already been + * locked (both pages and state bits are locked). + * + * This is done inside an ordered work queue, and the compression + * is spread across many cpus. The actual IO submission is step + * two, and the ordered work queue takes care of making sure that + * happens in the same order things were put onto the queue by + * writepages and friends. + * + * If this code finds it can't get good compression, it puts an + * entry onto the work queue to write the uncompressed bytes. This + * makes sure that both compressed inodes and uncompressed inodes + * are written in the same order that the flusher thread sent them + * down. + */ +static noinline int compress_file_range(struct async_chunk *async_chunk) +{ + struct inode *inode = async_chunk->inode; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + u64 blocksize = fs_info->sectorsize; + u64 start = async_chunk->start; + u64 end = async_chunk->end; + u64 actual_end; + u64 i_size; + int ret = 0; + struct page **pages = NULL; + unsigned long nr_pages; + unsigned long total_compressed = 0; + unsigned long total_in = 0; + int i; + int will_compress; + int compress_type = fs_info->compress_type; + int compressed_extents = 0; + int redirty = 0; + + inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1, + SZ_16K); + + /* + * We need to save i_size before now because it could change in between + * us evaluating the size and assigning it. This is because we lock and + * unlock the page in truncate and fallocate, and then modify the i_size + * later on. + * + * The barriers are to emulate READ_ONCE, remove that once i_size_read + * does that for us. + */ + barrier(); + i_size = i_size_read(inode); + barrier(); + actual_end = min_t(u64, i_size, end + 1); +again: + will_compress = 0; + nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1; + BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0); + nr_pages = min_t(unsigned long, nr_pages, + BTRFS_MAX_COMPRESSED / PAGE_SIZE); + + /* + * we don't want to send crud past the end of i_size through + * compression, that's just a waste of CPU time. So, if the + * end of the file is before the start of our current + * requested range of bytes, we bail out to the uncompressed + * cleanup code that can deal with all of this. + * + * It isn't really the fastest way to fix things, but this is a + * very uncommon corner. + */ + if (actual_end <= start) + goto cleanup_and_bail_uncompressed; + + total_compressed = actual_end - start; + + /* + * skip compression for a small file range(<=blocksize) that + * isn't an inline extent, since it doesn't save disk space at all. + */ + if (total_compressed <= blocksize && + (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size)) + goto cleanup_and_bail_uncompressed; + + total_compressed = min_t(unsigned long, total_compressed, + BTRFS_MAX_UNCOMPRESSED); + total_in = 0; + ret = 0; + + /* + * we do compression for mount -o compress and when the + * inode has not been flagged as nocompress. This flag can + * change at any time if we discover bad compression ratios. + */ + if (inode_need_compress(BTRFS_I(inode), start, end)) { + WARN_ON(pages); + pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS); + if (!pages) { + /* just bail out to the uncompressed code */ + nr_pages = 0; + goto cont; + } + + if (BTRFS_I(inode)->defrag_compress) + compress_type = BTRFS_I(inode)->defrag_compress; + else if (BTRFS_I(inode)->prop_compress) + compress_type = BTRFS_I(inode)->prop_compress; + + /* + * we need to call clear_page_dirty_for_io on each + * page in the range. Otherwise applications with the file + * mmap'd can wander in and change the page contents while + * we are compressing them. + * + * If the compression fails for any reason, we set the pages + * dirty again later on. + * + * Note that the remaining part is redirtied, the start pointer + * has moved, the end is the original one. + */ + if (!redirty) { + extent_range_clear_dirty_for_io(inode, start, end); + redirty = 1; + } + + /* Compression level is applied here and only here */ + ret = btrfs_compress_pages( + compress_type | (fs_info->compress_level << 4), + inode->i_mapping, start, + pages, + &nr_pages, + &total_in, + &total_compressed); + + if (!ret) { + unsigned long offset = offset_in_page(total_compressed); + struct page *page = pages[nr_pages - 1]; + char *kaddr; + + /* zero the tail end of the last page, we might be + * sending it down to disk + */ + if (offset) { + kaddr = kmap_atomic(page); + memset(kaddr + offset, 0, + PAGE_SIZE - offset); + kunmap_atomic(kaddr); + } + will_compress = 1; + } + } +cont: + if (start == 0) { + /* lets try to make an inline extent */ + if (ret || total_in < actual_end) { + /* we didn't compress the entire range, try + * to make an uncompressed inline extent. + */ + ret = cow_file_range_inline(BTRFS_I(inode), start, end, + 0, BTRFS_COMPRESS_NONE, + NULL); + } else { + /* try making a compressed inline extent */ + ret = cow_file_range_inline(BTRFS_I(inode), start, end, + total_compressed, + compress_type, pages); + } + if (ret <= 0) { + unsigned long clear_flags = EXTENT_DELALLOC | + EXTENT_DELALLOC_NEW | EXTENT_DEFRAG | + EXTENT_DO_ACCOUNTING; + unsigned long page_error_op; + + page_error_op = ret < 0 ? PAGE_SET_ERROR : 0; + + /* + * inline extent creation worked or returned error, + * we don't need to create any more async work items. + * Unlock and free up our temp pages. + * + * We use DO_ACCOUNTING here because we need the + * delalloc_release_metadata to be done _after_ we drop + * our outstanding extent for clearing delalloc for this + * range. + */ + extent_clear_unlock_delalloc(BTRFS_I(inode), start, end, + NULL, + clear_flags, + PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + page_error_op | + PAGE_END_WRITEBACK); + + /* + * Ensure we only free the compressed pages if we have + * them allocated, as we can still reach here with + * inode_need_compress() == false. + */ + if (pages) { + for (i = 0; i < nr_pages; i++) { + WARN_ON(pages[i]->mapping); + put_page(pages[i]); + } + kfree(pages); + } + return 0; + } + } + + if (will_compress) { + /* + * we aren't doing an inline extent round the compressed size + * up to a block size boundary so the allocator does sane + * things + */ + total_compressed = ALIGN(total_compressed, blocksize); + + /* + * one last check to make sure the compression is really a + * win, compare the page count read with the blocks on disk, + * compression must free at least one sector size + */ + total_in = ALIGN(total_in, PAGE_SIZE); + if (total_compressed + blocksize <= total_in) { + compressed_extents++; + + /* + * The async work queues will take care of doing actual + * allocation on disk for these compressed pages, and + * will submit them to the elevator. + */ + add_async_extent(async_chunk, start, total_in, + total_compressed, pages, nr_pages, + compress_type); + + if (start + total_in < end) { + start += total_in; + pages = NULL; + cond_resched(); + goto again; + } + return compressed_extents; + } + } + if (pages) { + /* + * the compression code ran but failed to make things smaller, + * free any pages it allocated and our page pointer array + */ + for (i = 0; i < nr_pages; i++) { + WARN_ON(pages[i]->mapping); + put_page(pages[i]); + } + kfree(pages); + pages = NULL; + total_compressed = 0; + nr_pages = 0; + + /* flag the file so we don't compress in the future */ + if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) && + !(BTRFS_I(inode)->prop_compress)) { + BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; + } + } +cleanup_and_bail_uncompressed: + /* + * No compression, but we still need to write the pages in the file + * we've been given so far. redirty the locked page if it corresponds + * to our extent and set things up for the async work queue to run + * cow_file_range to do the normal delalloc dance. + */ + if (async_chunk->locked_page && + (page_offset(async_chunk->locked_page) >= start && + page_offset(async_chunk->locked_page)) <= end) { + __set_page_dirty_nobuffers(async_chunk->locked_page); + /* unlocked later on in the async handlers */ + } + + if (redirty) + extent_range_redirty_for_io(inode, start, end); + add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0, + BTRFS_COMPRESS_NONE); + compressed_extents++; + + return compressed_extents; +} + +static void free_async_extent_pages(struct async_extent *async_extent) +{ + int i; + + if (!async_extent->pages) + return; + + for (i = 0; i < async_extent->nr_pages; i++) { + WARN_ON(async_extent->pages[i]->mapping); + put_page(async_extent->pages[i]); + } + kfree(async_extent->pages); + async_extent->nr_pages = 0; + async_extent->pages = NULL; +} + +/* + * phase two of compressed writeback. This is the ordered portion + * of the code, which only gets called in the order the work was + * queued. We walk all the async extents created by compress_file_range + * and send them down to the disk. + */ +static noinline void submit_compressed_extents(struct async_chunk *async_chunk) +{ + struct btrfs_inode *inode = BTRFS_I(async_chunk->inode); + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct async_extent *async_extent; + u64 alloc_hint = 0; + struct btrfs_key ins; + struct extent_map *em; + struct btrfs_root *root = inode->root; + struct extent_io_tree *io_tree = &inode->io_tree; + int ret = 0; + +again: + while (!list_empty(&async_chunk->extents)) { + async_extent = list_entry(async_chunk->extents.next, + struct async_extent, list); + list_del(&async_extent->list); + +retry: + lock_extent(io_tree, async_extent->start, + async_extent->start + async_extent->ram_size - 1); + /* did the compression code fall back to uncompressed IO? */ + if (!async_extent->pages) { + int page_started = 0; + unsigned long nr_written = 0; + + /* allocate blocks */ + ret = cow_file_range(inode, async_chunk->locked_page, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + &page_started, &nr_written, 0); + + /* JDM XXX */ + + /* + * if page_started, cow_file_range inserted an + * inline extent and took care of all the unlocking + * and IO for us. Otherwise, we need to submit + * all those pages down to the drive. + */ + if (!page_started && !ret) + extent_write_locked_range(&inode->vfs_inode, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + WB_SYNC_ALL); + else if (ret && async_chunk->locked_page) + unlock_page(async_chunk->locked_page); + kfree(async_extent); + cond_resched(); + continue; + } + + ret = btrfs_reserve_extent(root, async_extent->ram_size, + async_extent->compressed_size, + async_extent->compressed_size, + 0, alloc_hint, &ins, 1, 1); + if (ret) { + free_async_extent_pages(async_extent); + + if (ret == -ENOSPC) { + unlock_extent(io_tree, async_extent->start, + async_extent->start + + async_extent->ram_size - 1); + + /* + * we need to redirty the pages if we decide to + * fallback to uncompressed IO, otherwise we + * will not submit these pages down to lower + * layers. + */ + extent_range_redirty_for_io(&inode->vfs_inode, + async_extent->start, + async_extent->start + + async_extent->ram_size - 1); + + goto retry; + } + goto out_free; + } + /* + * here we're doing allocation and writeback of the + * compressed pages + */ + em = create_io_em(inode, async_extent->start, + async_extent->ram_size, /* len */ + async_extent->start, /* orig_start */ + ins.objectid, /* block_start */ + ins.offset, /* block_len */ + ins.offset, /* orig_block_len */ + async_extent->ram_size, /* ram_bytes */ + async_extent->compress_type, + BTRFS_ORDERED_COMPRESSED); + if (IS_ERR(em)) + /* ret value is not necessary due to void function */ + goto out_free_reserve; + free_extent_map(em); + + ret = btrfs_add_ordered_extent_compress(inode, + async_extent->start, + ins.objectid, + async_extent->ram_size, + ins.offset, + BTRFS_ORDERED_COMPRESSED, + async_extent->compress_type); + if (ret) { + btrfs_drop_extent_cache(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, 0); + goto out_free_reserve; + } + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + + /* + * clear dirty, set writeback and unlock the pages. + */ + extent_clear_unlock_delalloc(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + NULL, EXTENT_LOCKED | EXTENT_DELALLOC, + PAGE_UNLOCK | PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK); + if (btrfs_submit_compressed_write(inode, async_extent->start, + async_extent->ram_size, + ins.objectid, + ins.offset, async_extent->pages, + async_extent->nr_pages, + async_chunk->write_flags, + async_chunk->blkcg_css)) { + struct page *p = async_extent->pages[0]; + const u64 start = async_extent->start; + const u64 end = start + async_extent->ram_size - 1; + + p->mapping = inode->vfs_inode.i_mapping; + btrfs_writepage_endio_finish_ordered(p, start, end, 0); + + p->mapping = NULL; + extent_clear_unlock_delalloc(inode, start, end, NULL, 0, + PAGE_END_WRITEBACK | + PAGE_SET_ERROR); + free_async_extent_pages(async_extent); + } + alloc_hint = ins.objectid + ins.offset; + kfree(async_extent); + cond_resched(); + } + return; +out_free_reserve: + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1); +out_free: + extent_clear_unlock_delalloc(inode, async_extent->start, + async_extent->start + + async_extent->ram_size - 1, + NULL, EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DELALLOC_NEW | + EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING, + PAGE_UNLOCK | PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | + PAGE_SET_ERROR); + free_async_extent_pages(async_extent); + kfree(async_extent); + goto again; +} + +static u64 get_extent_allocation_hint(struct btrfs_inode *inode, u64 start, + u64 num_bytes) +{ + struct extent_map_tree *em_tree = &inode->extent_tree; + struct extent_map *em; + u64 alloc_hint = 0; + + read_lock(&em_tree->lock); + em = search_extent_mapping(em_tree, start, num_bytes); + if (em) { + /* + * if block start isn't an actual block number then find the + * first block in this inode and use that as a hint. If that + * block is also bogus then just don't worry about it. + */ + if (em->block_start >= EXTENT_MAP_LAST_BYTE) { + free_extent_map(em); + em = search_extent_mapping(em_tree, 0, 0); + if (em && em->block_start < EXTENT_MAP_LAST_BYTE) + alloc_hint = em->block_start; + if (em) + free_extent_map(em); + } else { + alloc_hint = em->block_start; + free_extent_map(em); + } + } + read_unlock(&em_tree->lock); + + return alloc_hint; +} + +/* + * when extent_io.c finds a delayed allocation range in the file, + * the call backs end up in this code. The basic idea is to + * allocate extents on disk for the range, and create ordered data structs + * in ram to track those extents. + * + * locked_page is the page that writepage had locked already. We use + * it to make sure we don't do extra locks or unlocks. + * + * *page_started is set to one if we unlock locked_page and do everything + * required to start IO on it. It may be clean and already done with + * IO when we return. + */ +static noinline int cow_file_range(struct btrfs_inode *inode, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written, int unlock) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + u64 alloc_hint = 0; + u64 num_bytes; + unsigned long ram_size; + u64 cur_alloc_size = 0; + u64 min_alloc_size; + u64 blocksize = fs_info->sectorsize; + struct btrfs_key ins; + struct extent_map *em; + unsigned clear_bits; + unsigned long page_ops; + bool extent_reserved = false; + int ret = 0; + + if (btrfs_is_free_space_inode(inode)) { + ret = -EINVAL; + goto out_unlock; + } + + num_bytes = ALIGN(end - start + 1, blocksize); + num_bytes = max(blocksize, num_bytes); + ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy)); + + inode_should_defrag(inode, start, end, num_bytes, SZ_64K); + + if (start == 0) { + /* lets try to make an inline extent */ + ret = cow_file_range_inline(inode, start, end, 0, + BTRFS_COMPRESS_NONE, NULL); + if (ret == 0) { + /* + * We use DO_ACCOUNTING here because we need the + * delalloc_release_metadata to be run _after_ we drop + * our outstanding extent for clearing delalloc for this + * range. + */ + extent_clear_unlock_delalloc(inode, start, end, NULL, + EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DELALLOC_NEW | EXTENT_DEFRAG | + EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + *nr_written = *nr_written + + (end - start + PAGE_SIZE) / PAGE_SIZE; + *page_started = 1; + goto out; + } else if (ret < 0) { + goto out_unlock; + } + } + + alloc_hint = get_extent_allocation_hint(inode, start, num_bytes); + btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0); + + /* + * Relocation relies on the relocated extents to have exactly the same + * size as the original extents. Normally writeback for relocation data + * extents follows a NOCOW path because relocation preallocates the + * extents. However, due to an operation such as scrub turning a block + * group to RO mode, it may fallback to COW mode, so we must make sure + * an extent allocated during COW has exactly the requested size and can + * not be split into smaller extents, otherwise relocation breaks and + * fails during the stage where it updates the bytenr of file extent + * items. + */ + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) + min_alloc_size = num_bytes; + else + min_alloc_size = fs_info->sectorsize; + + while (num_bytes > 0) { + cur_alloc_size = num_bytes; + ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size, + min_alloc_size, 0, alloc_hint, + &ins, 1, 1); + if (ret < 0) + goto out_unlock; + cur_alloc_size = ins.offset; + extent_reserved = true; + + ram_size = ins.offset; + em = create_io_em(inode, start, ins.offset, /* len */ + start, /* orig_start */ + ins.objectid, /* block_start */ + ins.offset, /* block_len */ + ins.offset, /* orig_block_len */ + ram_size, /* ram_bytes */ + BTRFS_COMPRESS_NONE, /* compress_type */ + BTRFS_ORDERED_REGULAR /* type */); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto out_reserve; + } + free_extent_map(em); + + ret = btrfs_add_ordered_extent(inode, start, ins.objectid, + ram_size, cur_alloc_size, 0); + if (ret) + goto out_drop_extent_cache; + + if (root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) { + ret = btrfs_reloc_clone_csums(inode, start, + cur_alloc_size); + /* + * Only drop cache here, and process as normal. + * + * We must not allow extent_clear_unlock_delalloc() + * at out_unlock label to free meta of this ordered + * extent, as its meta should be freed by + * btrfs_finish_ordered_io(). + * + * So we must continue until @start is increased to + * skip current ordered extent. + */ + if (ret) + btrfs_drop_extent_cache(inode, start, + start + ram_size - 1, 0); + } + + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + + /* we're not doing compressed IO, don't unlock the first + * page (which the caller expects to stay locked), don't + * clear any dirty bits and don't set any writeback bits + * + * Do set the Private2 bit so we know this page was properly + * setup for writepage + */ + page_ops = unlock ? PAGE_UNLOCK : 0; + page_ops |= PAGE_SET_PRIVATE2; + + extent_clear_unlock_delalloc(inode, start, start + ram_size - 1, + locked_page, + EXTENT_LOCKED | EXTENT_DELALLOC, + page_ops); + if (num_bytes < cur_alloc_size) + num_bytes = 0; + else + num_bytes -= cur_alloc_size; + alloc_hint = ins.objectid + ins.offset; + start += cur_alloc_size; + extent_reserved = false; + + /* + * btrfs_reloc_clone_csums() error, since start is increased + * extent_clear_unlock_delalloc() at out_unlock label won't + * free metadata of current ordered extent, we're OK to exit. + */ + if (ret) + goto out_unlock; + } +out: + return ret; + +out_drop_extent_cache: + btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0); +out_reserve: + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1); +out_unlock: + clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | + EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV; + page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK; + /* + * If we reserved an extent for our delalloc range (or a subrange) and + * failed to create the respective ordered extent, then it means that + * when we reserved the extent we decremented the extent's size from + * the data space_info's bytes_may_use counter and incremented the + * space_info's bytes_reserved counter by the same amount. We must make + * sure extent_clear_unlock_delalloc() does not try to decrement again + * the data space_info's bytes_may_use counter, therefore we do not pass + * it the flag EXTENT_CLEAR_DATA_RESV. + */ + if (extent_reserved) { + extent_clear_unlock_delalloc(inode, start, + start + cur_alloc_size - 1, + locked_page, + clear_bits, + page_ops); + start += cur_alloc_size; + if (start >= end) + goto out; + } + extent_clear_unlock_delalloc(inode, start, end, locked_page, + clear_bits | EXTENT_CLEAR_DATA_RESV, + page_ops); + goto out; +} + +/* + * work queue call back to started compression on a file and pages + */ +static noinline void async_cow_start(struct btrfs_work *work) +{ + struct async_chunk *async_chunk; + int compressed_extents; + + async_chunk = container_of(work, struct async_chunk, work); + + compressed_extents = compress_file_range(async_chunk); + if (compressed_extents == 0) { + btrfs_add_delayed_iput(async_chunk->inode); + async_chunk->inode = NULL; + } +} + +/* + * work queue call back to submit previously compressed pages + */ +static noinline void async_cow_submit(struct btrfs_work *work) +{ + struct async_chunk *async_chunk = container_of(work, struct async_chunk, + work); + struct btrfs_fs_info *fs_info = btrfs_work_owner(work); + unsigned long nr_pages; + + nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >> + PAGE_SHIFT; + + /* + * ->inode could be NULL if async_chunk_start has failed to compress, + * in which case we don't have anything to submit, yet we need to + * always adjust ->async_delalloc_pages as its paired with the init + * happening in cow_file_range_async + */ + if (async_chunk->inode) + submit_compressed_extents(async_chunk); + + /* atomic_sub_return implies a barrier */ + if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) < + 5 * SZ_1M) + cond_wake_up_nomb(&fs_info->async_submit_wait); +} + +static noinline void async_cow_free(struct btrfs_work *work) +{ + struct async_chunk *async_chunk; + + async_chunk = container_of(work, struct async_chunk, work); + if (async_chunk->inode) + btrfs_add_delayed_iput(async_chunk->inode); + if (async_chunk->blkcg_css) + css_put(async_chunk->blkcg_css); + /* + * Since the pointer to 'pending' is at the beginning of the array of + * async_chunk's, freeing it ensures the whole array has been freed. + */ + if (atomic_dec_and_test(async_chunk->pending)) + kvfree(async_chunk->pending); +} + +static int cow_file_range_async(struct btrfs_inode *inode, + struct writeback_control *wbc, + struct page *locked_page, + u64 start, u64 end, int *page_started, + unsigned long *nr_written) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc); + struct async_cow *ctx; + struct async_chunk *async_chunk; + unsigned long nr_pages; + u64 cur_end; + u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K); + int i; + bool should_compress; + unsigned nofs_flag; + const unsigned int write_flags = wbc_to_write_flags(wbc); + + unlock_extent(&inode->io_tree, start, end); + + if (inode->flags & BTRFS_INODE_NOCOMPRESS && + !btrfs_test_opt(fs_info, FORCE_COMPRESS)) { + num_chunks = 1; + should_compress = false; + } else { + should_compress = true; + } + + nofs_flag = memalloc_nofs_save(); + ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL); + memalloc_nofs_restore(nofs_flag); + + if (!ctx) { + unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DELALLOC_NEW | EXTENT_DEFRAG | + EXTENT_DO_ACCOUNTING; + unsigned long page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK | + PAGE_SET_ERROR; + + extent_clear_unlock_delalloc(inode, start, end, locked_page, + clear_bits, page_ops); + return -ENOMEM; + } + + async_chunk = ctx->chunks; + atomic_set(&ctx->num_chunks, num_chunks); + + for (i = 0; i < num_chunks; i++) { + if (should_compress) + cur_end = min(end, start + SZ_512K - 1); + else + cur_end = end; + + /* + * igrab is called higher up in the call chain, take only the + * lightweight reference for the callback lifetime + */ + ihold(&inode->vfs_inode); + async_chunk[i].pending = &ctx->num_chunks; + async_chunk[i].inode = &inode->vfs_inode; + async_chunk[i].start = start; + async_chunk[i].end = cur_end; + async_chunk[i].write_flags = write_flags; + INIT_LIST_HEAD(&async_chunk[i].extents); + + /* + * The locked_page comes all the way from writepage and its + * the original page we were actually given. As we spread + * this large delalloc region across multiple async_chunk + * structs, only the first struct needs a pointer to locked_page + * + * This way we don't need racey decisions about who is supposed + * to unlock it. + */ + if (locked_page) { + /* + * Depending on the compressibility, the pages might or + * might not go through async. We want all of them to + * be accounted against wbc once. Let's do it here + * before the paths diverge. wbc accounting is used + * only for foreign writeback detection and doesn't + * need full accuracy. Just account the whole thing + * against the first page. + */ + wbc_account_cgroup_owner(wbc, locked_page, + cur_end - start); + async_chunk[i].locked_page = locked_page; + locked_page = NULL; + } else { + async_chunk[i].locked_page = NULL; + } + + if (blkcg_css != blkcg_root_css) { + css_get(blkcg_css); + async_chunk[i].blkcg_css = blkcg_css; + } else { + async_chunk[i].blkcg_css = NULL; + } + + btrfs_init_work(&async_chunk[i].work, async_cow_start, + async_cow_submit, async_cow_free); + + nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE); + atomic_add(nr_pages, &fs_info->async_delalloc_pages); + + btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work); + + *nr_written += nr_pages; + start = cur_end + 1; + } + *page_started = 1; + return 0; +} + +static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info, + u64 bytenr, u64 num_bytes) +{ + int ret; + struct btrfs_ordered_sum *sums; + LIST_HEAD(list); + + ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr, + bytenr + num_bytes - 1, &list, 0); + if (ret == 0 && list_empty(&list)) + return 0; + + while (!list_empty(&list)) { + sums = list_entry(list.next, struct btrfs_ordered_sum, list); + list_del(&sums->list); + kfree(sums); + } + if (ret < 0) + return ret; + return 1; +} + +static int fallback_to_cow(struct btrfs_inode *inode, struct page *locked_page, + const u64 start, const u64 end, + int *page_started, unsigned long *nr_written) +{ + const bool is_space_ino = btrfs_is_free_space_inode(inode); + const bool is_reloc_ino = (inode->root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID); + const u64 range_bytes = end + 1 - start; + struct extent_io_tree *io_tree = &inode->io_tree; + u64 range_start = start; + u64 count; + + /* + * If EXTENT_NORESERVE is set it means that when the buffered write was + * made we had not enough available data space and therefore we did not + * reserve data space for it, since we though we could do NOCOW for the + * respective file range (either there is prealloc extent or the inode + * has the NOCOW bit set). + * + * However when we need to fallback to COW mode (because for example the + * block group for the corresponding extent was turned to RO mode by a + * scrub or relocation) we need to do the following: + * + * 1) We increment the bytes_may_use counter of the data space info. + * If COW succeeds, it allocates a new data extent and after doing + * that it decrements the space info's bytes_may_use counter and + * increments its bytes_reserved counter by the same amount (we do + * this at btrfs_add_reserved_bytes()). So we need to increment the + * bytes_may_use counter to compensate (when space is reserved at + * buffered write time, the bytes_may_use counter is incremented); + * + * 2) We clear the EXTENT_NORESERVE bit from the range. We do this so + * that if the COW path fails for any reason, it decrements (through + * extent_clear_unlock_delalloc()) the bytes_may_use counter of the + * data space info, which we incremented in the step above. + * + * If we need to fallback to cow and the inode corresponds to a free + * space cache inode or an inode of the data relocation tree, we must + * also increment bytes_may_use of the data space_info for the same + * reason. Space caches and relocated data extents always get a prealloc + * extent for them, however scrub or balance may have set the block + * group that contains that extent to RO mode and therefore force COW + * when starting writeback. + */ + count = count_range_bits(io_tree, &range_start, end, range_bytes, + EXTENT_NORESERVE, 0); + if (count > 0 || is_space_ino || is_reloc_ino) { + u64 bytes = count; + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_space_info *sinfo = fs_info->data_sinfo; + + if (is_space_ino || is_reloc_ino) + bytes = range_bytes; + + spin_lock(&sinfo->lock); + btrfs_space_info_update_bytes_may_use(fs_info, sinfo, bytes); + spin_unlock(&sinfo->lock); + + if (count > 0) + clear_extent_bit(io_tree, start, end, EXTENT_NORESERVE, + 0, 0, NULL); + } + + return cow_file_range(inode, locked_page, start, end, page_started, + nr_written, 1); +} + +/* + * when nowcow writeback call back. This checks for snapshots or COW copies + * of the extents that exist in the file, and COWs the file as required. + * + * If no cow copies or snapshots exist, we write directly to the existing + * blocks on disk + */ +static noinline int run_delalloc_nocow(struct btrfs_inode *inode, + struct page *locked_page, + const u64 start, const u64 end, + int *page_started, int force, + unsigned long *nr_written) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_root *root = inode->root; + struct btrfs_path *path; + u64 cow_start = (u64)-1; + u64 cur_offset = start; + int ret; + bool check_prev = true; + const bool freespace_inode = btrfs_is_free_space_inode(inode); + u64 ino = btrfs_ino(inode); + bool nocow = false; + u64 disk_bytenr = 0; + + path = btrfs_alloc_path(); + if (!path) { + extent_clear_unlock_delalloc(inode, start, end, locked_page, + EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + return -ENOMEM; + } + + while (1) { + struct btrfs_key found_key; + struct btrfs_file_extent_item *fi; + struct extent_buffer *leaf; + u64 extent_end; + u64 extent_offset; + u64 num_bytes = 0; + u64 disk_num_bytes; + u64 ram_bytes; + int extent_type; + + nocow = false; + + ret = btrfs_lookup_file_extent(NULL, root, path, ino, + cur_offset, 0); + if (ret < 0) + goto error; + + /* + * If there is no extent for our range when doing the initial + * search, then go back to the previous slot as it will be the + * one containing the search offset + */ + if (ret > 0 && path->slots[0] > 0 && check_prev) { + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, + path->slots[0] - 1); + if (found_key.objectid == ino && + found_key.type == BTRFS_EXTENT_DATA_KEY) + path->slots[0]--; + } + check_prev = false; +next_slot: + /* Go to next leaf if we have exhausted the current one */ + leaf = path->nodes[0]; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + if (ret > 0) + break; + leaf = path->nodes[0]; + } + + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + /* Didn't find anything for our INO */ + if (found_key.objectid > ino) + break; + /* + * Keep searching until we find an EXTENT_ITEM or there are no + * more extents for this inode + */ + if (WARN_ON_ONCE(found_key.objectid < ino) || + found_key.type < BTRFS_EXTENT_DATA_KEY) { + path->slots[0]++; + goto next_slot; + } + + /* Found key is not EXTENT_DATA_KEY or starts after req range */ + if (found_key.type > BTRFS_EXTENT_DATA_KEY || + found_key.offset > end) + break; + + /* + * If the found extent starts after requested offset, then + * adjust extent_end to be right before this extent begins + */ + if (found_key.offset > cur_offset) { + extent_end = found_key.offset; + extent_type = 0; + goto out_check; + } + + /* + * Found extent which begins before our range and potentially + * intersect it + */ + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + + ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + extent_offset = btrfs_file_extent_offset(leaf, fi); + extent_end = found_key.offset + + btrfs_file_extent_num_bytes(leaf, fi); + disk_num_bytes = + btrfs_file_extent_disk_num_bytes(leaf, fi); + /* + * If the extent we got ends before our current offset, + * skip to the next extent. + */ + if (extent_end <= cur_offset) { + path->slots[0]++; + goto next_slot; + } + /* Skip holes */ + if (disk_bytenr == 0) + goto out_check; + /* Skip compressed/encrypted/encoded extents */ + if (btrfs_file_extent_compression(leaf, fi) || + btrfs_file_extent_encryption(leaf, fi) || + btrfs_file_extent_other_encoding(leaf, fi)) + goto out_check; + /* + * If extent is created before the last volume's snapshot + * this implies the extent is shared, hence we can't do + * nocow. This is the same check as in + * btrfs_cross_ref_exist but without calling + * btrfs_search_slot. + */ + if (!freespace_inode && + btrfs_file_extent_generation(leaf, fi) <= + btrfs_root_last_snapshot(&root->root_item)) + goto out_check; + if (extent_type == BTRFS_FILE_EXTENT_REG && !force) + goto out_check; + /* If extent is RO, we must COW it */ + if (btrfs_extent_readonly(fs_info, disk_bytenr)) + goto out_check; + ret = btrfs_cross_ref_exist(root, ino, + found_key.offset - + extent_offset, disk_bytenr, false); + if (ret) { + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + + WARN_ON_ONCE(freespace_inode); + goto out_check; + } + disk_bytenr += extent_offset; + disk_bytenr += cur_offset - found_key.offset; + num_bytes = min(end + 1, extent_end) - cur_offset; + /* + * If there are pending snapshots for this root, we + * fall into common COW way + */ + if (!freespace_inode && atomic_read(&root->snapshot_force_cow)) + goto out_check; + /* + * force cow if csum exists in the range. + * this ensure that csum for a given extent are + * either valid or do not exist. + */ + ret = csum_exist_in_range(fs_info, disk_bytenr, + num_bytes); + if (ret) { + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + WARN_ON_ONCE(freespace_inode); + goto out_check; + } + if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) + goto out_check; + nocow = true; + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + extent_end = found_key.offset + ram_bytes; + extent_end = ALIGN(extent_end, fs_info->sectorsize); + /* Skip extents outside of our requested range */ + if (extent_end <= start) { + path->slots[0]++; + goto next_slot; + } + } else { + /* If this triggers then we have a memory corruption */ + BUG(); + } +out_check: + /* + * If nocow is false then record the beginning of the range + * that needs to be COWed + */ + if (!nocow) { + if (cow_start == (u64)-1) + cow_start = cur_offset; + cur_offset = extent_end; + if (cur_offset > end) + break; + path->slots[0]++; + goto next_slot; + } + + btrfs_release_path(path); + + /* + * COW range from cow_start to found_key.offset - 1. As the key + * will contain the beginning of the first extent that can be + * NOCOW, following one which needs to be COW'ed + */ + if (cow_start != (u64)-1) { + ret = fallback_to_cow(inode, locked_page, + cow_start, found_key.offset - 1, + page_started, nr_written); + if (ret) + goto error; + cow_start = (u64)-1; + } + + if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + u64 orig_start = found_key.offset - extent_offset; + struct extent_map *em; + + em = create_io_em(inode, cur_offset, num_bytes, + orig_start, + disk_bytenr, /* block_start */ + num_bytes, /* block_len */ + disk_num_bytes, /* orig_block_len */ + ram_bytes, BTRFS_COMPRESS_NONE, + BTRFS_ORDERED_PREALLOC); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto error; + } + free_extent_map(em); + ret = btrfs_add_ordered_extent(inode, cur_offset, + disk_bytenr, num_bytes, + num_bytes, + BTRFS_ORDERED_PREALLOC); + if (ret) { + btrfs_drop_extent_cache(inode, cur_offset, + cur_offset + num_bytes - 1, + 0); + goto error; + } + } else { + ret = btrfs_add_ordered_extent(inode, cur_offset, + disk_bytenr, num_bytes, + num_bytes, + BTRFS_ORDERED_NOCOW); + if (ret) + goto error; + } + + if (nocow) + btrfs_dec_nocow_writers(fs_info, disk_bytenr); + nocow = false; + + if (root->root_key.objectid == + BTRFS_DATA_RELOC_TREE_OBJECTID) + /* + * Error handled later, as we must prevent + * extent_clear_unlock_delalloc() in error handler + * from freeing metadata of created ordered extent. + */ + ret = btrfs_reloc_clone_csums(inode, cur_offset, + num_bytes); + + extent_clear_unlock_delalloc(inode, cur_offset, + cur_offset + num_bytes - 1, + locked_page, EXTENT_LOCKED | + EXTENT_DELALLOC | + EXTENT_CLEAR_DATA_RESV, + PAGE_UNLOCK | PAGE_SET_PRIVATE2); + + cur_offset = extent_end; + + /* + * btrfs_reloc_clone_csums() error, now we're OK to call error + * handler, as metadata for created ordered extent will only + * be freed by btrfs_finish_ordered_io(). + */ + if (ret) + goto error; + if (cur_offset > end) + break; + } + btrfs_release_path(path); + + if (cur_offset <= end && cow_start == (u64)-1) + cow_start = cur_offset; + + if (cow_start != (u64)-1) { + cur_offset = end; + ret = fallback_to_cow(inode, locked_page, cow_start, end, + page_started, nr_written); + if (ret) + goto error; + } + +error: + if (nocow) + btrfs_dec_nocow_writers(fs_info, disk_bytenr); + + if (ret && cur_offset < end) + extent_clear_unlock_delalloc(inode, cur_offset, end, + locked_page, EXTENT_LOCKED | + EXTENT_DELALLOC | EXTENT_DEFRAG | + EXTENT_DO_ACCOUNTING, PAGE_UNLOCK | + PAGE_CLEAR_DIRTY | + PAGE_SET_WRITEBACK | + PAGE_END_WRITEBACK); + btrfs_free_path(path); + return ret; +} + +static inline int need_force_cow(struct btrfs_inode *inode, u64 start, u64 end) +{ + + if (!(inode->flags & BTRFS_INODE_NODATACOW) && + !(inode->flags & BTRFS_INODE_PREALLOC)) + return 0; + + /* + * @defrag_bytes is a hint value, no spinlock held here, + * if is not zero, it means the file is defragging. + * Force cow if given extent needs to be defragged. + */ + if (inode->defrag_bytes && + test_range_bit(&inode->io_tree, start, end, EXTENT_DEFRAG, 0, NULL)) + return 1; + + return 0; +} + +/* + * Function to process delayed allocation (create CoW) for ranges which are + * being touched for the first time. + */ +int btrfs_run_delalloc_range(struct btrfs_inode *inode, struct page *locked_page, + u64 start, u64 end, int *page_started, unsigned long *nr_written, + struct writeback_control *wbc) +{ + int ret; + int force_cow = need_force_cow(inode, start, end); + + if (inode->flags & BTRFS_INODE_NODATACOW && !force_cow) { + ret = run_delalloc_nocow(inode, locked_page, start, end, + page_started, 1, nr_written); + } else if (inode->flags & BTRFS_INODE_PREALLOC && !force_cow) { + ret = run_delalloc_nocow(inode, locked_page, start, end, + page_started, 0, nr_written); + } else if (!inode_can_compress(inode) || + !inode_need_compress(inode, start, end)) { + ret = cow_file_range(inode, locked_page, start, end, + page_started, nr_written, 1); + } else { + set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &inode->runtime_flags); + ret = cow_file_range_async(inode, wbc, locked_page, start, end, + page_started, nr_written); + } + if (ret) + btrfs_cleanup_ordered_extents(inode, locked_page, start, + end - start + 1); + return ret; +} + +void btrfs_split_delalloc_extent(struct inode *inode, + struct extent_state *orig, u64 split) +{ + u64 size; + + /* not delalloc, ignore it */ + if (!(orig->state & EXTENT_DELALLOC)) + return; + + size = orig->end - orig->start + 1; + if (size > BTRFS_MAX_EXTENT_SIZE) { + u32 num_extents; + u64 new_size; + + /* + * See the explanation in btrfs_merge_delalloc_extent, the same + * applies here, just in reverse. + */ + new_size = orig->end - split + 1; + num_extents = count_max_extents(new_size); + new_size = split - orig->start; + num_extents += count_max_extents(new_size); + if (count_max_extents(size) >= num_extents) + return; + } + + spin_lock(&BTRFS_I(inode)->lock); + btrfs_mod_outstanding_extents(BTRFS_I(inode), 1); + spin_unlock(&BTRFS_I(inode)->lock); +} + +/* + * Handle merged delayed allocation extents so we can keep track of new extents + * that are just merged onto old extents, such as when we are doing sequential + * writes, so we can properly account for the metadata space we'll need. + */ +void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new, + struct extent_state *other) +{ + u64 new_size, old_size; + u32 num_extents; + + /* not delalloc, ignore it */ + if (!(other->state & EXTENT_DELALLOC)) + return; + + if (new->start > other->start) + new_size = new->end - other->start + 1; + else + new_size = other->end - new->start + 1; + + /* we're not bigger than the max, unreserve the space and go */ + if (new_size <= BTRFS_MAX_EXTENT_SIZE) { + spin_lock(&BTRFS_I(inode)->lock); + btrfs_mod_outstanding_extents(BTRFS_I(inode), -1); + spin_unlock(&BTRFS_I(inode)->lock); + return; + } + + /* + * We have to add up either side to figure out how many extents were + * accounted for before we merged into one big extent. If the number of + * extents we accounted for is <= the amount we need for the new range + * then we can return, otherwise drop. Think of it like this + * + * [ 4k][MAX_SIZE] + * + * So we've grown the extent by a MAX_SIZE extent, this would mean we + * need 2 outstanding extents, on one side we have 1 and the other side + * we have 1 so they are == and we can return. But in this case + * + * [MAX_SIZE+4k][MAX_SIZE+4k] + * + * Each range on their own accounts for 2 extents, but merged together + * they are only 3 extents worth of accounting, so we need to drop in + * this case. + */ + old_size = other->end - other->start + 1; + num_extents = count_max_extents(old_size); + old_size = new->end - new->start + 1; + num_extents += count_max_extents(old_size); + if (count_max_extents(new_size) >= num_extents) + return; + + spin_lock(&BTRFS_I(inode)->lock); + btrfs_mod_outstanding_extents(BTRFS_I(inode), -1); + spin_unlock(&BTRFS_I(inode)->lock); +} + +static void btrfs_add_delalloc_inodes(struct btrfs_root *root, + struct inode *inode) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + + spin_lock(&root->delalloc_lock); + if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) { + list_add_tail(&BTRFS_I(inode)->delalloc_inodes, + &root->delalloc_inodes); + set_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &BTRFS_I(inode)->runtime_flags); + root->nr_delalloc_inodes++; + if (root->nr_delalloc_inodes == 1) { + spin_lock(&fs_info->delalloc_root_lock); + BUG_ON(!list_empty(&root->delalloc_root)); + list_add_tail(&root->delalloc_root, + &fs_info->delalloc_roots); + spin_unlock(&fs_info->delalloc_root_lock); + } + } + spin_unlock(&root->delalloc_lock); +} + + +void __btrfs_del_delalloc_inode(struct btrfs_root *root, + struct btrfs_inode *inode) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + + if (!list_empty(&inode->delalloc_inodes)) { + list_del_init(&inode->delalloc_inodes); + clear_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &inode->runtime_flags); + root->nr_delalloc_inodes--; + if (!root->nr_delalloc_inodes) { + ASSERT(list_empty(&root->delalloc_inodes)); + spin_lock(&fs_info->delalloc_root_lock); + BUG_ON(list_empty(&root->delalloc_root)); + list_del_init(&root->delalloc_root); + spin_unlock(&fs_info->delalloc_root_lock); + } + } +} + +static void btrfs_del_delalloc_inode(struct btrfs_root *root, + struct btrfs_inode *inode) +{ + spin_lock(&root->delalloc_lock); + __btrfs_del_delalloc_inode(root, inode); + spin_unlock(&root->delalloc_lock); +} + +/* + * Properly track delayed allocation bytes in the inode and to maintain the + * list of inodes that have pending delalloc work to be done. + */ +void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state, + unsigned *bits) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + + if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC)) + WARN_ON(1); + /* + * set_bit and clear bit hooks normally require _irqsave/restore + * but in this case, we are only testing for the DELALLOC + * bit, which is only set or cleared with irqs on + */ + if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 len = state->end + 1 - state->start; + u32 num_extents = count_max_extents(len); + bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode)); + + spin_lock(&BTRFS_I(inode)->lock); + btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents); + spin_unlock(&BTRFS_I(inode)->lock); + + /* For sanity tests */ + if (btrfs_is_testing(fs_info)) + return; + + percpu_counter_add_batch(&fs_info->delalloc_bytes, len, + fs_info->delalloc_batch); + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->delalloc_bytes += len; + if (*bits & EXTENT_DEFRAG) + BTRFS_I(inode)->defrag_bytes += len; + if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &BTRFS_I(inode)->runtime_flags)) + btrfs_add_delalloc_inodes(root, inode); + spin_unlock(&BTRFS_I(inode)->lock); + } + + if (!(state->state & EXTENT_DELALLOC_NEW) && + (*bits & EXTENT_DELALLOC_NEW)) { + spin_lock(&BTRFS_I(inode)->lock); + BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 - + state->start; + spin_unlock(&BTRFS_I(inode)->lock); + } +} + +/* + * Once a range is no longer delalloc this function ensures that proper + * accounting happens. + */ +void btrfs_clear_delalloc_extent(struct inode *vfs_inode, + struct extent_state *state, unsigned *bits) +{ + struct btrfs_inode *inode = BTRFS_I(vfs_inode); + struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb); + u64 len = state->end + 1 - state->start; + u32 num_extents = count_max_extents(len); + + if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) { + spin_lock(&inode->lock); + inode->defrag_bytes -= len; + spin_unlock(&inode->lock); + } + + /* + * set_bit and clear bit hooks normally require _irqsave/restore + * but in this case, we are only testing for the DELALLOC + * bit, which is only set or cleared with irqs on + */ + if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) { + struct btrfs_root *root = inode->root; + bool do_list = !btrfs_is_free_space_inode(inode); + + spin_lock(&inode->lock); + btrfs_mod_outstanding_extents(inode, -num_extents); + spin_unlock(&inode->lock); + + /* + * We don't reserve metadata space for space cache inodes so we + * don't need to call delalloc_release_metadata if there is an + * error. + */ + if (*bits & EXTENT_CLEAR_META_RESV && + root != fs_info->tree_root) + btrfs_delalloc_release_metadata(inode, len, false); + + /* For sanity tests. */ + if (btrfs_is_testing(fs_info)) + return; + + if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID && + do_list && !(state->state & EXTENT_NORESERVE) && + (*bits & EXTENT_CLEAR_DATA_RESV)) + btrfs_free_reserved_data_space_noquota(fs_info, len); + + percpu_counter_add_batch(&fs_info->delalloc_bytes, -len, + fs_info->delalloc_batch); + spin_lock(&inode->lock); + inode->delalloc_bytes -= len; + if (do_list && inode->delalloc_bytes == 0 && + test_bit(BTRFS_INODE_IN_DELALLOC_LIST, + &inode->runtime_flags)) + btrfs_del_delalloc_inode(root, inode); + spin_unlock(&inode->lock); + } + + if ((state->state & EXTENT_DELALLOC_NEW) && + (*bits & EXTENT_DELALLOC_NEW)) { + spin_lock(&inode->lock); + ASSERT(inode->new_delalloc_bytes >= len); + inode->new_delalloc_bytes -= len; + spin_unlock(&inode->lock); + } +} + +/* + * btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit + * in a chunk's stripe. This function ensures that bios do not span a + * stripe/chunk + * + * @page - The page we are about to add to the bio + * @size - size we want to add to the bio + * @bio - bio we want to ensure is smaller than a stripe + * @bio_flags - flags of the bio + * + * return 1 if page cannot be added to the bio + * return 0 if page can be added to the bio + * return error otherwise + */ +int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio, + unsigned long bio_flags) +{ + struct inode *inode = page->mapping->host; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + u64 logical = (u64)bio->bi_iter.bi_sector << 9; + u64 length = 0; + u64 map_length; + int ret; + struct btrfs_io_geometry geom; + + if (bio_flags & EXTENT_BIO_COMPRESSED) + return 0; + + length = bio->bi_iter.bi_size; + map_length = length; + ret = btrfs_get_io_geometry(fs_info, btrfs_op(bio), logical, map_length, + &geom); + if (ret < 0) + return ret; + + if (geom.len < length + size) + return 1; + return 0; +} + +/* + * in order to insert checksums into the metadata in large chunks, + * we wait until bio submission time. All the pages in the bio are + * checksummed and sums are attached onto the ordered extent record. + * + * At IO completion time the cums attached on the ordered extent record + * are inserted into the btree + */ +static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio, + u64 bio_offset) +{ + struct inode *inode = private_data; + + return btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0); +} + +/* + * extent_io.c submission hook. This does the right thing for csum calculation + * on write, or reading the csums from the tree before a read. + * + * Rules about async/sync submit, + * a) read: sync submit + * + * b) write without checksum: sync submit + * + * c) write with checksum: + * c-1) if bio is issued by fsync: sync submit + * (sync_writers != 0) + * + * c-2) if root is reloc root: sync submit + * (only in case of buffered IO) + * + * c-3) otherwise: async submit + */ +blk_status_t btrfs_submit_data_bio(struct inode *inode, struct bio *bio, + int mirror_num, unsigned long bio_flags) + +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_root *root = BTRFS_I(inode)->root; + enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA; + blk_status_t ret = 0; + int skip_sum; + int async = !atomic_read(&BTRFS_I(inode)->sync_writers); + + skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM; + + if (btrfs_is_free_space_inode(BTRFS_I(inode))) + metadata = BTRFS_WQ_ENDIO_FREE_SPACE; + + if (bio_op(bio) != REQ_OP_WRITE) { + ret = btrfs_bio_wq_end_io(fs_info, bio, metadata); + if (ret) + goto out; + + if (bio_flags & EXTENT_BIO_COMPRESSED) { + ret = btrfs_submit_compressed_read(inode, bio, + mirror_num, + bio_flags); + goto out; + } else if (!skip_sum) { + ret = btrfs_lookup_bio_sums(inode, bio, (u64)-1, NULL); + if (ret) + goto out; + } + goto mapit; + } else if (async && !skip_sum) { + /* csum items have already been cloned */ + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) + goto mapit; + /* we're doing a write, do the async checksumming */ + ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags, + 0, inode, btrfs_submit_bio_start); + goto out; + } else if (!skip_sum) { + ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, 0, 0); + if (ret) + goto out; + } + +mapit: + ret = btrfs_map_bio(fs_info, bio, mirror_num); + +out: + if (ret) { + bio->bi_status = ret; + bio_endio(bio); + } + return ret; +} + +/* + * given a list of ordered sums record them in the inode. This happens + * at IO completion time based on sums calculated at bio submission time. + */ +static int add_pending_csums(struct btrfs_trans_handle *trans, + struct list_head *list) +{ + struct btrfs_ordered_sum *sum; + int ret; + + list_for_each_entry(sum, list, list) { + trans->adding_csums = true; + ret = btrfs_csum_file_blocks(trans, trans->fs_info->csum_root, sum); + trans->adding_csums = false; + if (ret) + return ret; + } + return 0; +} + +static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode, + const u64 start, + const u64 len, + struct extent_state **cached_state) +{ + u64 search_start = start; + const u64 end = start + len - 1; + + while (search_start < end) { + const u64 search_len = end - search_start + 1; + struct extent_map *em; + u64 em_len; + int ret = 0; + + em = btrfs_get_extent(inode, NULL, 0, search_start, search_len); + if (IS_ERR(em)) + return PTR_ERR(em); + + if (em->block_start != EXTENT_MAP_HOLE) + goto next; + + em_len = em->len; + if (em->start < search_start) + em_len -= search_start - em->start; + if (em_len > search_len) + em_len = search_len; + + ret = set_extent_bit(&inode->io_tree, search_start, + search_start + em_len - 1, + EXTENT_DELALLOC_NEW, + NULL, cached_state, GFP_NOFS); +next: + search_start = extent_map_end(em); + free_extent_map(em); + if (ret) + return ret; + } + return 0; +} + +int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end, + unsigned int extra_bits, + struct extent_state **cached_state) +{ + WARN_ON(PAGE_ALIGNED(end)); + + if (start >= i_size_read(&inode->vfs_inode) && + !(inode->flags & BTRFS_INODE_PREALLOC)) { + /* + * There can't be any extents following eof in this case so just + * set the delalloc new bit for the range directly. + */ + extra_bits |= EXTENT_DELALLOC_NEW; + } else { + int ret; + + ret = btrfs_find_new_delalloc_bytes(inode, start, + end + 1 - start, + cached_state); + if (ret) + return ret; + } + + return set_extent_delalloc(&inode->io_tree, start, end, extra_bits, + cached_state); +} + +/* see btrfs_writepage_start_hook for details on why this is required */ +struct btrfs_writepage_fixup { + struct page *page; + struct inode *inode; + struct btrfs_work work; +}; + +static void btrfs_writepage_fixup_worker(struct btrfs_work *work) +{ + struct btrfs_writepage_fixup *fixup; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + struct extent_changeset *data_reserved = NULL; + struct page *page; + struct btrfs_inode *inode; + u64 page_start; + u64 page_end; + int ret = 0; + bool free_delalloc_space = true; + + fixup = container_of(work, struct btrfs_writepage_fixup, work); + page = fixup->page; + inode = BTRFS_I(fixup->inode); + page_start = page_offset(page); + page_end = page_offset(page) + PAGE_SIZE - 1; + + /* + * This is similar to page_mkwrite, we need to reserve the space before + * we take the page lock. + */ + ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start, + PAGE_SIZE); +again: + lock_page(page); + + /* + * Before we queued this fixup, we took a reference on the page. + * page->mapping may go NULL, but it shouldn't be moved to a different + * address space. + */ + if (!page->mapping || !PageDirty(page) || !PageChecked(page)) { + /* + * Unfortunately this is a little tricky, either + * + * 1) We got here and our page had already been dealt with and + * we reserved our space, thus ret == 0, so we need to just + * drop our space reservation and bail. This can happen the + * first time we come into the fixup worker, or could happen + * while waiting for the ordered extent. + * 2) Our page was already dealt with, but we happened to get an + * ENOSPC above from the btrfs_delalloc_reserve_space. In + * this case we obviously don't have anything to release, but + * because the page was already dealt with we don't want to + * mark the page with an error, so make sure we're resetting + * ret to 0. This is why we have this check _before_ the ret + * check, because we do not want to have a surprise ENOSPC + * when the page was already properly dealt with. + */ + if (!ret) { + btrfs_delalloc_release_extents(inode, PAGE_SIZE); + btrfs_delalloc_release_space(inode, data_reserved, + page_start, PAGE_SIZE, + true); + } + ret = 0; + goto out_page; + } + + /* + * We can't mess with the page state unless it is locked, so now that + * it is locked bail if we failed to make our space reservation. + */ + if (ret) + goto out_page; + + lock_extent_bits(&inode->io_tree, page_start, page_end, &cached_state); + + /* already ordered? We're done */ + if (PagePrivate2(page)) + goto out_reserved; + + ordered = btrfs_lookup_ordered_range(inode, page_start, PAGE_SIZE); + if (ordered) { + unlock_extent_cached(&inode->io_tree, page_start, page_end, + &cached_state); + unlock_page(page); + btrfs_start_ordered_extent(ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0, + &cached_state); + if (ret) + goto out_reserved; + + /* + * Everything went as planned, we're now the owner of a dirty page with + * delayed allocation bits set and space reserved for our COW + * destination. + * + * The page was dirty when we started, nothing should have cleaned it. + */ + BUG_ON(!PageDirty(page)); + free_delalloc_space = false; +out_reserved: + btrfs_delalloc_release_extents(inode, PAGE_SIZE); + if (free_delalloc_space) + btrfs_delalloc_release_space(inode, data_reserved, page_start, + PAGE_SIZE, true); + unlock_extent_cached(&inode->io_tree, page_start, page_end, + &cached_state); +out_page: + if (ret) { + /* + * We hit ENOSPC or other errors. Update the mapping and page + * to reflect the errors and clean the page. + */ + mapping_set_error(page->mapping, ret); + end_extent_writepage(page, ret, page_start, page_end); + clear_page_dirty_for_io(page); + SetPageError(page); + } + ClearPageChecked(page); + unlock_page(page); + put_page(page); + kfree(fixup); + extent_changeset_free(data_reserved); + /* + * As a precaution, do a delayed iput in case it would be the last iput + * that could need flushing space. Recursing back to fixup worker would + * deadlock. + */ + btrfs_add_delayed_iput(&inode->vfs_inode); +} + +/* + * There are a few paths in the higher layers of the kernel that directly + * set the page dirty bit without asking the filesystem if it is a + * good idea. This causes problems because we want to make sure COW + * properly happens and the data=ordered rules are followed. + * + * In our case any range that doesn't have the ORDERED bit set + * hasn't been properly setup for IO. We kick off an async process + * to fix it up. The async helper will wait for ordered extents, set + * the delalloc bit and make it safe to write the page. + */ +int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end) +{ + struct inode *inode = page->mapping->host; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_writepage_fixup *fixup; + + /* this page is properly in the ordered list */ + if (TestClearPagePrivate2(page)) + return 0; + + /* + * PageChecked is set below when we create a fixup worker for this page, + * don't try to create another one if we're already PageChecked() + * + * The extent_io writepage code will redirty the page if we send back + * EAGAIN. + */ + if (PageChecked(page)) + return -EAGAIN; + + fixup = kzalloc(sizeof(*fixup), GFP_NOFS); + if (!fixup) + return -EAGAIN; + + /* + * We are already holding a reference to this inode from + * write_cache_pages. We need to hold it because the space reservation + * takes place outside of the page lock, and we can't trust + * page->mapping outside of the page lock. + */ + ihold(inode); + SetPageChecked(page); + get_page(page); + btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL); + fixup->page = page; + fixup->inode = inode; + btrfs_queue_work(fs_info->fixup_workers, &fixup->work); + + return -EAGAIN; +} + +static int insert_reserved_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode, u64 file_pos, + struct btrfs_file_extent_item *stack_fi, + u64 qgroup_reserved) +{ + struct btrfs_root *root = inode->root; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key ins; + u64 disk_num_bytes = btrfs_stack_file_extent_disk_num_bytes(stack_fi); + u64 disk_bytenr = btrfs_stack_file_extent_disk_bytenr(stack_fi); + u64 num_bytes = btrfs_stack_file_extent_num_bytes(stack_fi); + u64 ram_bytes = btrfs_stack_file_extent_ram_bytes(stack_fi); + int extent_inserted = 0; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * we may be replacing one extent in the tree with another. + * The new extent is pinned in the extent map, and we don't want + * to drop it from the cache until it is completely in the btree. + * + * So, tell btrfs_drop_extents to leave this extent in the cache. + * the caller is expected to unpin it and allow it to be merged + * with the others. + */ + ret = __btrfs_drop_extents(trans, root, inode, path, file_pos, + file_pos + num_bytes, NULL, 0, + 1, sizeof(*stack_fi), &extent_inserted); + if (ret) + goto out; + + if (!extent_inserted) { + ins.objectid = btrfs_ino(inode); + ins.offset = file_pos; + ins.type = BTRFS_EXTENT_DATA_KEY; + + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, root, path, &ins, + sizeof(*stack_fi)); + if (ret) + goto out; + } + leaf = path->nodes[0]; + btrfs_set_stack_file_extent_generation(stack_fi, trans->transid); + write_extent_buffer(leaf, stack_fi, + btrfs_item_ptr_offset(leaf, path->slots[0]), + sizeof(struct btrfs_file_extent_item)); + + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(path); + + inode_add_bytes(&inode->vfs_inode, num_bytes); + + ins.objectid = disk_bytenr; + ins.offset = disk_num_bytes; + ins.type = BTRFS_EXTENT_ITEM_KEY; + + ret = btrfs_inode_set_file_extent_range(inode, file_pos, ram_bytes); + if (ret) + goto out; + + ret = btrfs_alloc_reserved_file_extent(trans, root, btrfs_ino(inode), + file_pos, qgroup_reserved, &ins); +out: + btrfs_free_path(path); + + return ret; +} + +static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info, + u64 start, u64 len) +{ + struct btrfs_block_group *cache; + + cache = btrfs_lookup_block_group(fs_info, start); + ASSERT(cache); + + spin_lock(&cache->lock); + cache->delalloc_bytes -= len; + spin_unlock(&cache->lock); + + btrfs_put_block_group(cache); +} + +static int insert_ordered_extent_file_extent(struct btrfs_trans_handle *trans, + struct btrfs_ordered_extent *oe) +{ + struct btrfs_file_extent_item stack_fi; + u64 logical_len; + + memset(&stack_fi, 0, sizeof(stack_fi)); + btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_REG); + btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, oe->disk_bytenr); + btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi, + oe->disk_num_bytes); + if (test_bit(BTRFS_ORDERED_TRUNCATED, &oe->flags)) + logical_len = oe->truncated_len; + else + logical_len = oe->num_bytes; + btrfs_set_stack_file_extent_num_bytes(&stack_fi, logical_len); + btrfs_set_stack_file_extent_ram_bytes(&stack_fi, logical_len); + btrfs_set_stack_file_extent_compression(&stack_fi, oe->compress_type); + /* Encryption and other encoding is reserved and all 0 */ + + return insert_reserved_file_extent(trans, BTRFS_I(oe->inode), + oe->file_offset, &stack_fi, + oe->qgroup_rsv); +} + +/* + * As ordered data IO finishes, this gets called so we can finish + * an ordered extent if the range of bytes in the file it covers are + * fully written. + */ +static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent) +{ + struct inode *inode = ordered_extent->inode; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans = NULL; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_state *cached_state = NULL; + u64 start, end; + int compress_type = 0; + int ret = 0; + u64 logical_len = ordered_extent->num_bytes; + bool freespace_inode; + bool truncated = false; + bool range_locked = false; + bool clear_new_delalloc_bytes = false; + bool clear_reserved_extent = true; + unsigned int clear_bits; + + start = ordered_extent->file_offset; + end = start + ordered_extent->num_bytes - 1; + + if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && + !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) && + !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags)) + clear_new_delalloc_bytes = true; + + freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode)); + + if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) { + ret = -EIO; + goto out; + } + + btrfs_free_io_failure_record(BTRFS_I(inode), start, end); + + if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) { + truncated = true; + logical_len = ordered_extent->truncated_len; + /* Truncated the entire extent, don't bother adding */ + if (!logical_len) + goto out; + } + + if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) { + BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */ + + btrfs_inode_safe_disk_i_size_write(inode, 0); + if (freespace_inode) + trans = btrfs_join_transaction_spacecache(root); + else + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + trans->block_rsv = &BTRFS_I(inode)->block_rsv; + ret = btrfs_update_inode_fallback(trans, root, inode); + if (ret) /* -ENOMEM or corruption */ + btrfs_abort_transaction(trans, ret); + goto out; + } + + range_locked = true; + lock_extent_bits(io_tree, start, end, &cached_state); + + if (freespace_inode) + trans = btrfs_join_transaction_spacecache(root); + else + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; + } + + trans->block_rsv = &BTRFS_I(inode)->block_rsv; + + if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags)) + compress_type = ordered_extent->compress_type; + if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { + BUG_ON(compress_type); + ret = btrfs_mark_extent_written(trans, BTRFS_I(inode), + ordered_extent->file_offset, + ordered_extent->file_offset + + logical_len); + } else { + BUG_ON(root == fs_info->tree_root); + ret = insert_ordered_extent_file_extent(trans, ordered_extent); + if (!ret) { + clear_reserved_extent = false; + btrfs_release_delalloc_bytes(fs_info, + ordered_extent->disk_bytenr, + ordered_extent->disk_num_bytes); + } + } + unpin_extent_cache(&BTRFS_I(inode)->extent_tree, + ordered_extent->file_offset, + ordered_extent->num_bytes, trans->transid); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + ret = add_pending_csums(trans, &ordered_extent->list); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + btrfs_inode_safe_disk_i_size_write(inode, 0); + ret = btrfs_update_inode_fallback(trans, root, inode); + if (ret) { /* -ENOMEM or corruption */ + btrfs_abort_transaction(trans, ret); + goto out; + } + ret = 0; +out: + clear_bits = EXTENT_DEFRAG; + if (range_locked) + clear_bits |= EXTENT_LOCKED; + if (clear_new_delalloc_bytes) + clear_bits |= EXTENT_DELALLOC_NEW; + clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits, + (clear_bits & EXTENT_LOCKED) ? 1 : 0, 0, + &cached_state); + + if (trans) + btrfs_end_transaction(trans); + + if (ret || truncated) { + u64 unwritten_start = start; + + /* + * If we failed to finish this ordered extent for any reason we + * need to make sure BTRFS_ORDERED_IOERR is set on the ordered + * extent, and mark the inode with the error if it wasn't + * already set. Any error during writeback would have already + * set the mapping error, so we need to set it if we're the ones + * marking this ordered extent as failed. + */ + if (ret && !test_and_set_bit(BTRFS_ORDERED_IOERR, + &ordered_extent->flags)) + mapping_set_error(ordered_extent->inode->i_mapping, -EIO); + + if (truncated) + unwritten_start += logical_len; + clear_extent_uptodate(io_tree, unwritten_start, end, NULL); + + /* Drop the cache for the part of the extent we didn't write. */ + btrfs_drop_extent_cache(BTRFS_I(inode), unwritten_start, end, 0); + + /* + * If the ordered extent had an IOERR or something else went + * wrong we need to return the space for this ordered extent + * back to the allocator. We only free the extent in the + * truncated case if we didn't write out the extent at all. + * + * If we made it past insert_reserved_file_extent before we + * errored out then we don't need to do this as the accounting + * has already been done. + */ + if ((ret || !logical_len) && + clear_reserved_extent && + !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) && + !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) { + /* + * Discard the range before returning it back to the + * free space pool + */ + if (ret && btrfs_test_opt(fs_info, DISCARD_SYNC)) + btrfs_discard_extent(fs_info, + ordered_extent->disk_bytenr, + ordered_extent->disk_num_bytes, + NULL); + btrfs_free_reserved_extent(fs_info, + ordered_extent->disk_bytenr, + ordered_extent->disk_num_bytes, 1); + } + } + + /* + * This needs to be done to make sure anybody waiting knows we are done + * updating everything for this ordered extent. + */ + btrfs_remove_ordered_extent(BTRFS_I(inode), ordered_extent); + + /* once for us */ + btrfs_put_ordered_extent(ordered_extent); + /* once for the tree */ + btrfs_put_ordered_extent(ordered_extent); + + return ret; +} + +static void finish_ordered_fn(struct btrfs_work *work) +{ + struct btrfs_ordered_extent *ordered_extent; + ordered_extent = container_of(work, struct btrfs_ordered_extent, work); + btrfs_finish_ordered_io(ordered_extent); +} + +void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start, + u64 end, int uptodate) +{ + struct btrfs_inode *inode = BTRFS_I(page->mapping->host); + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_ordered_extent *ordered_extent = NULL; + struct btrfs_workqueue *wq; + + trace_btrfs_writepage_end_io_hook(page, start, end, uptodate); + + ClearPagePrivate2(page); + if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start, + end - start + 1, uptodate)) + return; + + if (btrfs_is_free_space_inode(inode)) + wq = fs_info->endio_freespace_worker; + else + wq = fs_info->endio_write_workers; + + btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL); + btrfs_queue_work(wq, &ordered_extent->work); +} + +static int check_data_csum(struct inode *inode, struct btrfs_io_bio *io_bio, + int icsum, struct page *page, int pgoff, u64 start, + size_t len) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + SHASH_DESC_ON_STACK(shash, fs_info->csum_shash); + char *kaddr; + u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + u8 *csum_expected; + u8 csum[BTRFS_CSUM_SIZE]; + + csum_expected = ((u8 *)io_bio->csum) + icsum * csum_size; + + kaddr = kmap_atomic(page); + shash->tfm = fs_info->csum_shash; + + crypto_shash_digest(shash, kaddr + pgoff, len, csum); + + if (memcmp(csum, csum_expected, csum_size)) + goto zeroit; + + kunmap_atomic(kaddr); + return 0; +zeroit: + btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected, + io_bio->mirror_num); + if (io_bio->device) + btrfs_dev_stat_inc_and_print(io_bio->device, + BTRFS_DEV_STAT_CORRUPTION_ERRS); + memset(kaddr + pgoff, 1, len); + flush_dcache_page(page); + kunmap_atomic(kaddr); + return -EIO; +} + +/* + * when reads are done, we need to check csums to verify the data is correct + * if there's a match, we allow the bio to finish. If not, the code in + * extent_io.c will try to find good copies for us. + */ +int btrfs_verify_data_csum(struct btrfs_io_bio *io_bio, u64 phy_offset, + struct page *page, u64 start, u64 end, int mirror) +{ + size_t offset = start - page_offset(page); + struct inode *inode = page->mapping->host; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (PageChecked(page)) { + ClearPageChecked(page); + return 0; + } + + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) + return 0; + + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID && + test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) { + clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM); + return 0; + } + + phy_offset >>= inode->i_sb->s_blocksize_bits; + return check_data_csum(inode, io_bio, phy_offset, page, offset, start, + (size_t)(end - start + 1)); +} + +/* + * btrfs_add_delayed_iput - perform a delayed iput on @inode + * + * @inode: The inode we want to perform iput on + * + * This function uses the generic vfs_inode::i_count to track whether we should + * just decrement it (in case it's > 1) or if this is the last iput then link + * the inode to the delayed iput machinery. Delayed iputs are processed at + * transaction commit time/superblock commit/cleaner kthread. + */ +void btrfs_add_delayed_iput(struct inode *inode) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_inode *binode = BTRFS_I(inode); + + if (atomic_add_unless(&inode->i_count, -1, 1)) + return; + + atomic_inc(&fs_info->nr_delayed_iputs); + spin_lock(&fs_info->delayed_iput_lock); + ASSERT(list_empty(&binode->delayed_iput)); + list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs); + spin_unlock(&fs_info->delayed_iput_lock); + if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags)) + wake_up_process(fs_info->cleaner_kthread); +} + +static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info, + struct btrfs_inode *inode) +{ + list_del_init(&inode->delayed_iput); + spin_unlock(&fs_info->delayed_iput_lock); + iput(&inode->vfs_inode); + if (atomic_dec_and_test(&fs_info->nr_delayed_iputs)) + wake_up(&fs_info->delayed_iputs_wait); + spin_lock(&fs_info->delayed_iput_lock); +} + +static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info, + struct btrfs_inode *inode) +{ + if (!list_empty(&inode->delayed_iput)) { + spin_lock(&fs_info->delayed_iput_lock); + if (!list_empty(&inode->delayed_iput)) + run_delayed_iput_locked(fs_info, inode); + spin_unlock(&fs_info->delayed_iput_lock); + } +} + +void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info) +{ + + spin_lock(&fs_info->delayed_iput_lock); + while (!list_empty(&fs_info->delayed_iputs)) { + struct btrfs_inode *inode; + + inode = list_first_entry(&fs_info->delayed_iputs, + struct btrfs_inode, delayed_iput); + run_delayed_iput_locked(fs_info, inode); + cond_resched_lock(&fs_info->delayed_iput_lock); + } + spin_unlock(&fs_info->delayed_iput_lock); +} + +/** + * btrfs_wait_on_delayed_iputs - wait on the delayed iputs to be done running + * @fs_info - the fs_info for this fs + * @return - EINTR if we were killed, 0 if nothing's pending + * + * This will wait on any delayed iputs that are currently running with KILLABLE + * set. Once they are all done running we will return, unless we are killed in + * which case we return EINTR. This helps in user operations like fallocate etc + * that might get blocked on the iputs. + */ +int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info) +{ + int ret = wait_event_killable(fs_info->delayed_iputs_wait, + atomic_read(&fs_info->nr_delayed_iputs) == 0); + if (ret) + return -EINTR; + return 0; +} + +/* + * This creates an orphan entry for the given inode in case something goes wrong + * in the middle of an unlink. + */ +int btrfs_orphan_add(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + int ret; + + ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode)); + if (ret && ret != -EEXIST) { + btrfs_abort_transaction(trans, ret); + return ret; + } + + return 0; +} + +/* + * We have done the delete so we can go ahead and remove the orphan item for + * this particular inode. + */ +static int btrfs_orphan_del(struct btrfs_trans_handle *trans, + struct btrfs_inode *inode) +{ + return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode)); +} + +/* + * this cleans up any orphans that may be left on the list from the last use + * of this root. + */ +int btrfs_orphan_cleanup(struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_key key, found_key; + struct btrfs_trans_handle *trans; + struct inode *inode; + u64 last_objectid = 0; + int ret = 0, nr_unlink = 0; + + if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED)) + return 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + path->reada = READA_BACK; + + key.objectid = BTRFS_ORPHAN_OBJECTID; + key.type = BTRFS_ORPHAN_ITEM_KEY; + key.offset = (u64)-1; + + while (1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + /* + * if ret == 0 means we found what we were searching for, which + * is weird, but possible, so only screw with path if we didn't + * find the key and see if we have stuff that matches + */ + if (ret > 0) { + ret = 0; + if (path->slots[0] == 0) + break; + path->slots[0]--; + } + + /* pull out the item */ + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + /* make sure the item matches what we want */ + if (found_key.objectid != BTRFS_ORPHAN_OBJECTID) + break; + if (found_key.type != BTRFS_ORPHAN_ITEM_KEY) + break; + + /* release the path since we're done with it */ + btrfs_release_path(path); + + /* + * this is where we are basically btrfs_lookup, without the + * crossing root thing. we store the inode number in the + * offset of the orphan item. + */ + + if (found_key.offset == last_objectid) { + btrfs_err(fs_info, + "Error removing orphan entry, stopping orphan cleanup"); + ret = -EINVAL; + goto out; + } + + last_objectid = found_key.offset; + + found_key.objectid = found_key.offset; + found_key.type = BTRFS_INODE_ITEM_KEY; + found_key.offset = 0; + inode = btrfs_iget(fs_info->sb, last_objectid, root); + ret = PTR_ERR_OR_ZERO(inode); + if (ret && ret != -ENOENT) + goto out; + + if (ret == -ENOENT && root == fs_info->tree_root) { + struct btrfs_root *dead_root; + int is_dead_root = 0; + + /* + * this is an orphan in the tree root. Currently these + * could come from 2 sources: + * a) a snapshot deletion in progress + * b) a free space cache inode + * We need to distinguish those two, as the snapshot + * orphan must not get deleted. + * find_dead_roots already ran before us, so if this + * is a snapshot deletion, we should find the root + * in the fs_roots radix tree. + */ + + spin_lock(&fs_info->fs_roots_radix_lock); + dead_root = radix_tree_lookup(&fs_info->fs_roots_radix, + (unsigned long)found_key.objectid); + if (dead_root && btrfs_root_refs(&dead_root->root_item) == 0) + is_dead_root = 1; + spin_unlock(&fs_info->fs_roots_radix_lock); + + if (is_dead_root) { + /* prevent this orphan from being found again */ + key.offset = found_key.objectid - 1; + continue; + } + + } + + /* + * If we have an inode with links, there are a couple of + * possibilities. Old kernels (before v3.12) used to create an + * orphan item for truncate indicating that there were possibly + * extent items past i_size that needed to be deleted. In v3.12, + * truncate was changed to update i_size in sync with the extent + * items, but the (useless) orphan item was still created. Since + * v4.18, we don't create the orphan item for truncate at all. + * + * So, this item could mean that we need to do a truncate, but + * only if this filesystem was last used on a pre-v3.12 kernel + * and was not cleanly unmounted. The odds of that are quite + * slim, and it's a pain to do the truncate now, so just delete + * the orphan item. + * + * It's also possible that this orphan item was supposed to be + * deleted but wasn't. The inode number may have been reused, + * but either way, we can delete the orphan item. + */ + if (ret == -ENOENT || inode->i_nlink) { + if (!ret) + iput(inode); + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + btrfs_debug(fs_info, "auto deleting %Lu", + found_key.objectid); + ret = btrfs_del_orphan_item(trans, root, + found_key.objectid); + btrfs_end_transaction(trans); + if (ret) + goto out; + continue; + } + + nr_unlink++; + + /* this will do delete_inode and everything for us */ + iput(inode); + } + /* release the path since we're done with it */ + btrfs_release_path(path); + + root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE; + + if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) { + trans = btrfs_join_transaction(root); + if (!IS_ERR(trans)) + btrfs_end_transaction(trans); + } + + if (nr_unlink) + btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink); + +out: + if (ret) + btrfs_err(fs_info, "could not do orphan cleanup %d", ret); + btrfs_free_path(path); + return ret; +} + +/* + * very simple check to peek ahead in the leaf looking for xattrs. If we + * don't find any xattrs, we know there can't be any acls. + * + * slot is the slot the inode is in, objectid is the objectid of the inode + */ +static noinline int acls_after_inode_item(struct extent_buffer *leaf, + int slot, u64 objectid, + int *first_xattr_slot) +{ + u32 nritems = btrfs_header_nritems(leaf); + struct btrfs_key found_key; + static u64 xattr_access = 0; + static u64 xattr_default = 0; + int scanned = 0; + + if (!xattr_access) { + xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS, + strlen(XATTR_NAME_POSIX_ACL_ACCESS)); + xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT, + strlen(XATTR_NAME_POSIX_ACL_DEFAULT)); + } + + slot++; + *first_xattr_slot = -1; + while (slot < nritems) { + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + /* we found a different objectid, there must not be acls */ + if (found_key.objectid != objectid) + return 0; + + /* we found an xattr, assume we've got an acl */ + if (found_key.type == BTRFS_XATTR_ITEM_KEY) { + if (*first_xattr_slot == -1) + *first_xattr_slot = slot; + if (found_key.offset == xattr_access || + found_key.offset == xattr_default) + return 1; + } + + /* + * we found a key greater than an xattr key, there can't + * be any acls later on + */ + if (found_key.type > BTRFS_XATTR_ITEM_KEY) + return 0; + + slot++; + scanned++; + + /* + * it goes inode, inode backrefs, xattrs, extents, + * so if there are a ton of hard links to an inode there can + * be a lot of backrefs. Don't waste time searching too hard, + * this is just an optimization + */ + if (scanned >= 8) + break; + } + /* we hit the end of the leaf before we found an xattr or + * something larger than an xattr. We have to assume the inode + * has acls + */ + if (*first_xattr_slot == -1) + *first_xattr_slot = slot; + return 1; +} + +/* + * read an inode from the btree into the in-memory inode + */ +static int btrfs_read_locked_inode(struct inode *inode, + struct btrfs_path *in_path) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_path *path = in_path; + struct extent_buffer *leaf; + struct btrfs_inode_item *inode_item; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key location; + unsigned long ptr; + int maybe_acls; + u32 rdev; + int ret; + bool filled = false; + int first_xattr_slot; + + ret = btrfs_fill_inode(inode, &rdev); + if (!ret) + filled = true; + + if (!path) { + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + } + + memcpy(&location, &BTRFS_I(inode)->location, sizeof(location)); + + ret = btrfs_lookup_inode(NULL, root, path, &location, 0); + if (ret) { + if (path != in_path) + btrfs_free_path(path); + return ret; + } + + leaf = path->nodes[0]; + + if (filled) + goto cache_index; + + inode_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_inode_item); + inode->i_mode = btrfs_inode_mode(leaf, inode_item); + set_nlink(inode, btrfs_inode_nlink(leaf, inode_item)); + i_uid_write(inode, btrfs_inode_uid(leaf, inode_item)); + i_gid_write(inode, btrfs_inode_gid(leaf, inode_item)); + btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item)); + btrfs_inode_set_file_extent_range(BTRFS_I(inode), 0, + round_up(i_size_read(inode), fs_info->sectorsize)); + + inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime); + inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime); + + inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime); + inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime); + + inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime); + inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime); + + BTRFS_I(inode)->i_otime.tv_sec = + btrfs_timespec_sec(leaf, &inode_item->otime); + BTRFS_I(inode)->i_otime.tv_nsec = + btrfs_timespec_nsec(leaf, &inode_item->otime); + + inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item)); + BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item); + BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item); + + inode_set_iversion_queried(inode, + btrfs_inode_sequence(leaf, inode_item)); + inode->i_generation = BTRFS_I(inode)->generation; + inode->i_rdev = 0; + rdev = btrfs_inode_rdev(leaf, inode_item); + + BTRFS_I(inode)->index_cnt = (u64)-1; + BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item); + +cache_index: + /* + * If we were modified in the current generation and evicted from memory + * and then re-read we need to do a full sync since we don't have any + * idea about which extents were modified before we were evicted from + * cache. + * + * This is required for both inode re-read from disk and delayed inode + * in delayed_nodes_tree. + */ + if (BTRFS_I(inode)->last_trans == fs_info->generation) + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + + /* + * We don't persist the id of the transaction where an unlink operation + * against the inode was last made. So here we assume the inode might + * have been evicted, and therefore the exact value of last_unlink_trans + * lost, and set it to last_trans to avoid metadata inconsistencies + * between the inode and its parent if the inode is fsync'ed and the log + * replayed. For example, in the scenario: + * + * touch mydir/foo + * ln mydir/foo mydir/bar + * sync + * unlink mydir/bar + * echo 2 > /proc/sys/vm/drop_caches # evicts inode + * xfs_io -c fsync mydir/foo + * <power failure> + * mount fs, triggers fsync log replay + * + * We must make sure that when we fsync our inode foo we also log its + * parent inode, otherwise after log replay the parent still has the + * dentry with the "bar" name but our inode foo has a link count of 1 + * and doesn't have an inode ref with the name "bar" anymore. + * + * Setting last_unlink_trans to last_trans is a pessimistic approach, + * but it guarantees correctness at the expense of occasional full + * transaction commits on fsync if our inode is a directory, or if our + * inode is not a directory, logging its parent unnecessarily. + */ + BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans; + + /* + * Same logic as for last_unlink_trans. We don't persist the generation + * of the last transaction where this inode was used for a reflink + * operation, so after eviction and reloading the inode we must be + * pessimistic and assume the last transaction that modified the inode. + */ + BTRFS_I(inode)->last_reflink_trans = BTRFS_I(inode)->last_trans; + + path->slots[0]++; + if (inode->i_nlink != 1 || + path->slots[0] >= btrfs_header_nritems(leaf)) + goto cache_acl; + + btrfs_item_key_to_cpu(leaf, &location, path->slots[0]); + if (location.objectid != btrfs_ino(BTRFS_I(inode))) + goto cache_acl; + + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + if (location.type == BTRFS_INODE_REF_KEY) { + struct btrfs_inode_ref *ref; + + ref = (struct btrfs_inode_ref *)ptr; + BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref); + } else if (location.type == BTRFS_INODE_EXTREF_KEY) { + struct btrfs_inode_extref *extref; + + extref = (struct btrfs_inode_extref *)ptr; + BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf, + extref); + } +cache_acl: + /* + * try to precache a NULL acl entry for files that don't have + * any xattrs or acls + */ + maybe_acls = acls_after_inode_item(leaf, path->slots[0], + btrfs_ino(BTRFS_I(inode)), &first_xattr_slot); + if (first_xattr_slot != -1) { + path->slots[0] = first_xattr_slot; + ret = btrfs_load_inode_props(inode, path); + if (ret) + btrfs_err(fs_info, + "error loading props for ino %llu (root %llu): %d", + btrfs_ino(BTRFS_I(inode)), + root->root_key.objectid, ret); + } + if (path != in_path) + btrfs_free_path(path); + + if (!maybe_acls) + cache_no_acl(inode); + + switch (inode->i_mode & S_IFMT) { + case S_IFREG: + inode->i_mapping->a_ops = &btrfs_aops; + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + break; + case S_IFDIR: + inode->i_fop = &btrfs_dir_file_operations; + inode->i_op = &btrfs_dir_inode_operations; + break; + case S_IFLNK: + inode->i_op = &btrfs_symlink_inode_operations; + inode_nohighmem(inode); + inode->i_mapping->a_ops = &btrfs_aops; + break; + default: + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, rdev); + break; + } + + btrfs_sync_inode_flags_to_i_flags(inode); + return 0; +} + +/* + * given a leaf and an inode, copy the inode fields into the leaf + */ +static void fill_inode_item(struct btrfs_trans_handle *trans, + struct extent_buffer *leaf, + struct btrfs_inode_item *item, + struct inode *inode) +{ + struct btrfs_map_token token; + + btrfs_init_map_token(&token, leaf); + + btrfs_set_token_inode_uid(&token, item, i_uid_read(inode)); + btrfs_set_token_inode_gid(&token, item, i_gid_read(inode)); + btrfs_set_token_inode_size(&token, item, BTRFS_I(inode)->disk_i_size); + btrfs_set_token_inode_mode(&token, item, inode->i_mode); + btrfs_set_token_inode_nlink(&token, item, inode->i_nlink); + + btrfs_set_token_timespec_sec(&token, &item->atime, + inode->i_atime.tv_sec); + btrfs_set_token_timespec_nsec(&token, &item->atime, + inode->i_atime.tv_nsec); + + btrfs_set_token_timespec_sec(&token, &item->mtime, + inode->i_mtime.tv_sec); + btrfs_set_token_timespec_nsec(&token, &item->mtime, + inode->i_mtime.tv_nsec); + + btrfs_set_token_timespec_sec(&token, &item->ctime, + inode->i_ctime.tv_sec); + btrfs_set_token_timespec_nsec(&token, &item->ctime, + inode->i_ctime.tv_nsec); + + btrfs_set_token_timespec_sec(&token, &item->otime, + BTRFS_I(inode)->i_otime.tv_sec); + btrfs_set_token_timespec_nsec(&token, &item->otime, + BTRFS_I(inode)->i_otime.tv_nsec); + + btrfs_set_token_inode_nbytes(&token, item, inode_get_bytes(inode)); + btrfs_set_token_inode_generation(&token, item, + BTRFS_I(inode)->generation); + btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode)); + btrfs_set_token_inode_transid(&token, item, trans->transid); + btrfs_set_token_inode_rdev(&token, item, inode->i_rdev); + btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags); + btrfs_set_token_inode_block_group(&token, item, 0); +} + +/* + * copy everything in the in-memory inode into the btree. + */ +static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode) +{ + struct btrfs_inode_item *inode_item; + struct btrfs_path *path; + struct extent_buffer *leaf; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + path->leave_spinning = 1; + ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location, + 1); + if (ret) { + if (ret > 0) + ret = -ENOENT; + goto failed; + } + + leaf = path->nodes[0]; + inode_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_inode_item); + + fill_inode_item(trans, leaf, inode_item, inode); + btrfs_mark_buffer_dirty(leaf); + btrfs_set_inode_last_trans(trans, BTRFS_I(inode)); + ret = 0; +failed: + btrfs_free_path(path); + return ret; +} + +/* + * copy everything in the in-memory inode into the btree. + */ +noinline int btrfs_update_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct inode *inode) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + int ret; + + /* + * If the inode is a free space inode, we can deadlock during commit + * if we put it into the delayed code. + * + * The data relocation inode should also be directly updated + * without delay + */ + if (!btrfs_is_free_space_inode(BTRFS_I(inode)) + && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID + && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) { + btrfs_update_root_times(trans, root); + + ret = btrfs_delayed_update_inode(trans, root, inode); + if (!ret) + btrfs_set_inode_last_trans(trans, BTRFS_I(inode)); + return ret; + } + + return btrfs_update_inode_item(trans, root, inode); +} + +noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode) +{ + int ret; + + ret = btrfs_update_inode(trans, root, inode); + if (ret == -ENOSPC) + return btrfs_update_inode_item(trans, root, inode); + return ret; +} + +/* + * unlink helper that gets used here in inode.c and in the tree logging + * recovery code. It remove a link in a directory with a given name, and + * also drops the back refs in the inode to the directory + */ +static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_inode *dir, + struct btrfs_inode *inode, + const char *name, int name_len) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_path *path; + int ret = 0; + struct btrfs_dir_item *di; + u64 index; + u64 ino = btrfs_ino(inode); + u64 dir_ino = btrfs_ino(dir); + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + path->leave_spinning = 1; + di = btrfs_lookup_dir_item(trans, root, path, dir_ino, + name, name_len, -1); + if (IS_ERR_OR_NULL(di)) { + ret = di ? PTR_ERR(di) : -ENOENT; + goto err; + } + ret = btrfs_delete_one_dir_name(trans, root, path, di); + if (ret) + goto err; + btrfs_release_path(path); + + /* + * If we don't have dir index, we have to get it by looking up + * the inode ref, since we get the inode ref, remove it directly, + * it is unnecessary to do delayed deletion. + * + * But if we have dir index, needn't search inode ref to get it. + * Since the inode ref is close to the inode item, it is better + * that we delay to delete it, and just do this deletion when + * we update the inode item. + */ + if (inode->dir_index) { + ret = btrfs_delayed_delete_inode_ref(inode); + if (!ret) { + index = inode->dir_index; + goto skip_backref; + } + } + + ret = btrfs_del_inode_ref(trans, root, name, name_len, ino, + dir_ino, &index); + if (ret) { + btrfs_info(fs_info, + "failed to delete reference to %.*s, inode %llu parent %llu", + name_len, name, ino, dir_ino); + btrfs_abort_transaction(trans, ret); + goto err; + } +skip_backref: + ret = btrfs_delete_delayed_dir_index(trans, dir, index); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto err; + } + + ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode, + dir_ino); + if (ret != 0 && ret != -ENOENT) { + btrfs_abort_transaction(trans, ret); + goto err; + } + + ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir, + index); + if (ret == -ENOENT) + ret = 0; + else if (ret) + btrfs_abort_transaction(trans, ret); + + /* + * If we have a pending delayed iput we could end up with the final iput + * being run in btrfs-cleaner context. If we have enough of these built + * up we can end up burning a lot of time in btrfs-cleaner without any + * way to throttle the unlinks. Since we're currently holding a ref on + * the inode we can run the delayed iput here without any issues as the + * final iput won't be done until after we drop the ref we're currently + * holding. + */ + btrfs_run_delayed_iput(fs_info, inode); +err: + btrfs_free_path(path); + if (ret) + goto out; + + btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2); + inode_inc_iversion(&inode->vfs_inode); + inode_inc_iversion(&dir->vfs_inode); + inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime = + dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode); + ret = btrfs_update_inode(trans, root, &dir->vfs_inode); +out: + return ret; +} + +int btrfs_unlink_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_inode *dir, struct btrfs_inode *inode, + const char *name, int name_len) +{ + int ret; + ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len); + if (!ret) { + drop_nlink(&inode->vfs_inode); + ret = btrfs_update_inode(trans, root, &inode->vfs_inode); + } + return ret; +} + +/* + * helper to start transaction for unlink and rmdir. + * + * unlink and rmdir are special in btrfs, they do not always free space, so + * if we cannot make our reservations the normal way try and see if there is + * plenty of slack room in the global reserve to migrate, otherwise we cannot + * allow the unlink to occur. + */ +static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir) +{ + struct btrfs_root *root = BTRFS_I(dir)->root; + + /* + * 1 for the possible orphan item + * 1 for the dir item + * 1 for the dir index + * 1 for the inode ref + * 1 for the inode + */ + return btrfs_start_transaction_fallback_global_rsv(root, 5); +} + +static int btrfs_unlink(struct inode *dir, struct dentry *dentry) +{ + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_trans_handle *trans; + struct inode *inode = d_inode(dentry); + int ret; + + trans = __unlink_start_trans(dir); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)), + 0); + + ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), + BTRFS_I(d_inode(dentry)), dentry->d_name.name, + dentry->d_name.len); + if (ret) + goto out; + + if (inode->i_nlink == 0) { + ret = btrfs_orphan_add(trans, BTRFS_I(inode)); + if (ret) + goto out; + } + +out: + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(root->fs_info); + return ret; +} + +static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans, + struct inode *dir, struct dentry *dentry) +{ + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_inode *inode = BTRFS_I(d_inode(dentry)); + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_dir_item *di; + struct btrfs_key key; + const char *name = dentry->d_name.name; + int name_len = dentry->d_name.len; + u64 index; + int ret; + u64 objectid; + u64 dir_ino = btrfs_ino(BTRFS_I(dir)); + + if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) { + objectid = inode->root->root_key.objectid; + } else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) { + objectid = inode->location.objectid; + } else { + WARN_ON(1); + return -EINVAL; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + di = btrfs_lookup_dir_item(trans, root, path, dir_ino, + name, name_len, -1); + if (IS_ERR_OR_NULL(di)) { + ret = di ? PTR_ERR(di) : -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + btrfs_dir_item_key_to_cpu(leaf, di, &key); + WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid); + ret = btrfs_delete_one_dir_name(trans, root, path, di); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + btrfs_release_path(path); + + /* + * This is a placeholder inode for a subvolume we didn't have a + * reference to at the time of the snapshot creation. In the meantime + * we could have renamed the real subvol link into our snapshot, so + * depending on btrfs_del_root_ref to return -ENOENT here is incorret. + * Instead simply lookup the dir_index_item for this entry so we can + * remove it. Otherwise we know we have a ref to the root and we can + * call btrfs_del_root_ref, and it _shouldn't_ fail. + */ + if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) { + di = btrfs_search_dir_index_item(root, path, dir_ino, + name, name_len); + if (IS_ERR_OR_NULL(di)) { + if (!di) + ret = -ENOENT; + else + ret = PTR_ERR(di); + btrfs_abort_transaction(trans, ret); + goto out; + } + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + index = key.offset; + btrfs_release_path(path); + } else { + ret = btrfs_del_root_ref(trans, objectid, + root->root_key.objectid, dir_ino, + &index, name, name_len); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + } + + ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out; + } + + btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2); + inode_inc_iversion(dir); + dir->i_mtime = dir->i_ctime = current_time(dir); + ret = btrfs_update_inode_fallback(trans, root, dir); + if (ret) + btrfs_abort_transaction(trans, ret); +out: + btrfs_free_path(path); + return ret; +} + +/* + * Helper to check if the subvolume references other subvolumes or if it's + * default. + */ +static noinline int may_destroy_subvol(struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_path *path; + struct btrfs_dir_item *di; + struct btrfs_key key; + u64 dir_id; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* Make sure this root isn't set as the default subvol */ + dir_id = btrfs_super_root_dir(fs_info->super_copy); + di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path, + dir_id, "default", 7, 0); + if (di && !IS_ERR(di)) { + btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key); + if (key.objectid == root->root_key.objectid) { + ret = -EPERM; + btrfs_err(fs_info, + "deleting default subvolume %llu is not allowed", + key.objectid); + goto out; + } + btrfs_release_path(path); + } + + key.objectid = root->root_key.objectid; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0); + if (ret < 0) + goto out; + BUG_ON(ret == 0); + + ret = 0; + if (path->slots[0] > 0) { + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); + if (key.objectid == root->root_key.objectid && + key.type == BTRFS_ROOT_REF_KEY) + ret = -ENOTEMPTY; + } +out: + btrfs_free_path(path); + return ret; +} + +/* Delete all dentries for inodes belonging to the root */ +static void btrfs_prune_dentries(struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct rb_node *node; + struct rb_node *prev; + struct btrfs_inode *entry; + struct inode *inode; + u64 objectid = 0; + + if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) + WARN_ON(btrfs_root_refs(&root->root_item) != 0); + + spin_lock(&root->inode_lock); +again: + node = root->inode_tree.rb_node; + prev = NULL; + while (node) { + prev = node; + entry = rb_entry(node, struct btrfs_inode, rb_node); + + if (objectid < btrfs_ino(entry)) + node = node->rb_left; + else if (objectid > btrfs_ino(entry)) + node = node->rb_right; + else + break; + } + if (!node) { + while (prev) { + entry = rb_entry(prev, struct btrfs_inode, rb_node); + if (objectid <= btrfs_ino(entry)) { + node = prev; + break; + } + prev = rb_next(prev); + } + } + while (node) { + entry = rb_entry(node, struct btrfs_inode, rb_node); + objectid = btrfs_ino(entry) + 1; + inode = igrab(&entry->vfs_inode); + if (inode) { + spin_unlock(&root->inode_lock); + if (atomic_read(&inode->i_count) > 1) + d_prune_aliases(inode); + /* + * btrfs_drop_inode will have it removed from the inode + * cache when its usage count hits zero. + */ + iput(inode); + cond_resched(); + spin_lock(&root->inode_lock); + goto again; + } + + if (cond_resched_lock(&root->inode_lock)) + goto again; + + node = rb_next(node); + } + spin_unlock(&root->inode_lock); +} + +int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = d_inode(dentry); + struct btrfs_root *dest = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + struct btrfs_block_rsv block_rsv; + u64 root_flags; + int ret; + int err; + + /* + * Don't allow to delete a subvolume with send in progress. This is + * inside the inode lock so the error handling that has to drop the bit + * again is not run concurrently. + */ + spin_lock(&dest->root_item_lock); + if (dest->send_in_progress) { + spin_unlock(&dest->root_item_lock); + btrfs_warn(fs_info, + "attempt to delete subvolume %llu during send", + dest->root_key.objectid); + return -EPERM; + } + if (atomic_read(&dest->nr_swapfiles)) { + spin_unlock(&dest->root_item_lock); + btrfs_warn(fs_info, + "attempt to delete subvolume %llu with active swapfile", + root->root_key.objectid); + return -EPERM; + } + root_flags = btrfs_root_flags(&dest->root_item); + btrfs_set_root_flags(&dest->root_item, + root_flags | BTRFS_ROOT_SUBVOL_DEAD); + spin_unlock(&dest->root_item_lock); + + down_write(&fs_info->subvol_sem); + + err = may_destroy_subvol(dest); + if (err) + goto out_up_write; + + btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP); + /* + * One for dir inode, + * two for dir entries, + * two for root ref/backref. + */ + err = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true); + if (err) + goto out_up_write; + + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto out_release; + } + trans->block_rsv = &block_rsv; + trans->bytes_reserved = block_rsv.size; + + btrfs_record_snapshot_destroy(trans, BTRFS_I(dir)); + + ret = btrfs_unlink_subvol(trans, dir, dentry); + if (ret) { + err = ret; + btrfs_abort_transaction(trans, ret); + goto out_end_trans; + } + + btrfs_record_root_in_trans(trans, dest); + + memset(&dest->root_item.drop_progress, 0, + sizeof(dest->root_item.drop_progress)); + dest->root_item.drop_level = 0; + btrfs_set_root_refs(&dest->root_item, 0); + + if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) { + ret = btrfs_insert_orphan_item(trans, + fs_info->tree_root, + dest->root_key.objectid); + if (ret) { + btrfs_abort_transaction(trans, ret); + err = ret; + goto out_end_trans; + } + } + + ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid, + BTRFS_UUID_KEY_SUBVOL, + dest->root_key.objectid); + if (ret && ret != -ENOENT) { + btrfs_abort_transaction(trans, ret); + err = ret; + goto out_end_trans; + } + if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) { + ret = btrfs_uuid_tree_remove(trans, + dest->root_item.received_uuid, + BTRFS_UUID_KEY_RECEIVED_SUBVOL, + dest->root_key.objectid); + if (ret && ret != -ENOENT) { + btrfs_abort_transaction(trans, ret); + err = ret; + goto out_end_trans; + } + } + + free_anon_bdev(dest->anon_dev); + dest->anon_dev = 0; +out_end_trans: + trans->block_rsv = NULL; + trans->bytes_reserved = 0; + ret = btrfs_end_transaction(trans); + if (ret && !err) + err = ret; + inode->i_flags |= S_DEAD; +out_release: + btrfs_subvolume_release_metadata(root, &block_rsv); +out_up_write: + up_write(&fs_info->subvol_sem); + if (err) { + spin_lock(&dest->root_item_lock); + root_flags = btrfs_root_flags(&dest->root_item); + btrfs_set_root_flags(&dest->root_item, + root_flags & ~BTRFS_ROOT_SUBVOL_DEAD); + spin_unlock(&dest->root_item_lock); + } else { + d_invalidate(dentry); + btrfs_prune_dentries(dest); + ASSERT(dest->send_in_progress == 0); + + /* the last ref */ + if (dest->ino_cache_inode) { + iput(dest->ino_cache_inode); + dest->ino_cache_inode = NULL; + } + } + + return err; +} + +static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + struct inode *inode = d_inode(dentry); + int err = 0; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_trans_handle *trans; + u64 last_unlink_trans; + + if (inode->i_size > BTRFS_EMPTY_DIR_SIZE) + return -ENOTEMPTY; + if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID) + return btrfs_delete_subvolume(dir, dentry); + + trans = __unlink_start_trans(dir); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { + err = btrfs_unlink_subvol(trans, dir, dentry); + goto out; + } + + err = btrfs_orphan_add(trans, BTRFS_I(inode)); + if (err) + goto out; + + last_unlink_trans = BTRFS_I(inode)->last_unlink_trans; + + /* now the directory is empty */ + err = btrfs_unlink_inode(trans, root, BTRFS_I(dir), + BTRFS_I(d_inode(dentry)), dentry->d_name.name, + dentry->d_name.len); + if (!err) { + btrfs_i_size_write(BTRFS_I(inode), 0); + /* + * Propagate the last_unlink_trans value of the deleted dir to + * its parent directory. This is to prevent an unrecoverable + * log tree in the case we do something like this: + * 1) create dir foo + * 2) create snapshot under dir foo + * 3) delete the snapshot + * 4) rmdir foo + * 5) mkdir foo + * 6) fsync foo or some file inside foo + */ + if (last_unlink_trans >= trans->transid) + BTRFS_I(dir)->last_unlink_trans = last_unlink_trans; + } +out: + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(root->fs_info); + + return err; +} + +/* + * Return this if we need to call truncate_block for the last bit of the + * truncate. + */ +#define NEED_TRUNCATE_BLOCK 1 + +/* + * this can truncate away extent items, csum items and directory items. + * It starts at a high offset and removes keys until it can't find + * any higher than new_size + * + * csum items that cross the new i_size are truncated to the new size + * as well. + * + * min_type is the minimum key type to truncate down to. If set to 0, this + * will kill all the items on this inode, including the INODE_ITEM_KEY. + */ +int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *inode, + u64 new_size, u32 min_type) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_file_extent_item *fi; + struct btrfs_key key; + struct btrfs_key found_key; + u64 extent_start = 0; + u64 extent_num_bytes = 0; + u64 extent_offset = 0; + u64 item_end = 0; + u64 last_size = new_size; + u32 found_type = (u8)-1; + int found_extent; + int del_item; + int pending_del_nr = 0; + int pending_del_slot = 0; + int extent_type = -1; + int ret; + u64 ino = btrfs_ino(BTRFS_I(inode)); + u64 bytes_deleted = 0; + bool be_nice = false; + bool should_throttle = false; + const u64 lock_start = ALIGN_DOWN(new_size, fs_info->sectorsize); + struct extent_state *cached_state = NULL; + + BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); + + /* + * For non-free space inodes and non-shareable roots, we want to back + * off from time to time. This means all inodes in subvolume roots, + * reloc roots, and data reloc roots. + */ + if (!btrfs_is_free_space_inode(BTRFS_I(inode)) && + test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) + be_nice = true; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = READA_BACK; + + if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { + lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, (u64)-1, + &cached_state); + + /* + * We want to drop from the next block forward in case this + * new size is not block aligned since we will be keeping the + * last block of the extent just the way it is. + */ + btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size, + fs_info->sectorsize), + (u64)-1, 0); + } + + /* + * This function is also used to drop the items in the log tree before + * we relog the inode, so if root != BTRFS_I(inode)->root, it means + * it is used to drop the logged items. So we shouldn't kill the delayed + * items. + */ + if (min_type == 0 && root == BTRFS_I(inode)->root) + btrfs_kill_delayed_inode_items(BTRFS_I(inode)); + + key.objectid = ino; + key.offset = (u64)-1; + key.type = (u8)-1; + +search_again: + /* + * with a 16K leaf size and 128MB extents, you can actually queue + * up a huge file in a single leaf. Most of the time that + * bytes_deleted is > 0, it will be huge by the time we get here + */ + if (be_nice && bytes_deleted > SZ_32M && + btrfs_should_end_transaction(trans)) { + ret = -EAGAIN; + goto out; + } + + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret < 0) + goto out; + + if (ret > 0) { + ret = 0; + /* there are no items in the tree for us to truncate, we're + * done + */ + if (path->slots[0] == 0) + goto out; + path->slots[0]--; + } + + while (1) { + u64 clear_start = 0, clear_len = 0; + + fi = NULL; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + found_type = found_key.type; + + if (found_key.objectid != ino) + break; + + if (found_type < min_type) + break; + + item_end = found_key.offset; + if (found_type == BTRFS_EXTENT_DATA_KEY) { + fi = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + extent_type = btrfs_file_extent_type(leaf, fi); + if (extent_type != BTRFS_FILE_EXTENT_INLINE) { + item_end += + btrfs_file_extent_num_bytes(leaf, fi); + + trace_btrfs_truncate_show_fi_regular( + BTRFS_I(inode), leaf, fi, + found_key.offset); + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + item_end += btrfs_file_extent_ram_bytes(leaf, + fi); + + trace_btrfs_truncate_show_fi_inline( + BTRFS_I(inode), leaf, fi, path->slots[0], + found_key.offset); + } + item_end--; + } + if (found_type > min_type) { + del_item = 1; + } else { + if (item_end < new_size) + break; + if (found_key.offset >= new_size) + del_item = 1; + else + del_item = 0; + } + found_extent = 0; + /* FIXME, shrink the extent if the ref count is only 1 */ + if (found_type != BTRFS_EXTENT_DATA_KEY) + goto delete; + + if (extent_type != BTRFS_FILE_EXTENT_INLINE) { + u64 num_dec; + + clear_start = found_key.offset; + extent_start = btrfs_file_extent_disk_bytenr(leaf, fi); + if (!del_item) { + u64 orig_num_bytes = + btrfs_file_extent_num_bytes(leaf, fi); + extent_num_bytes = ALIGN(new_size - + found_key.offset, + fs_info->sectorsize); + clear_start = ALIGN(new_size, fs_info->sectorsize); + btrfs_set_file_extent_num_bytes(leaf, fi, + extent_num_bytes); + num_dec = (orig_num_bytes - + extent_num_bytes); + if (test_bit(BTRFS_ROOT_SHAREABLE, + &root->state) && + extent_start != 0) + inode_sub_bytes(inode, num_dec); + btrfs_mark_buffer_dirty(leaf); + } else { + extent_num_bytes = + btrfs_file_extent_disk_num_bytes(leaf, + fi); + extent_offset = found_key.offset - + btrfs_file_extent_offset(leaf, fi); + + /* FIXME blocksize != 4096 */ + num_dec = btrfs_file_extent_num_bytes(leaf, fi); + if (extent_start != 0) { + found_extent = 1; + if (test_bit(BTRFS_ROOT_SHAREABLE, + &root->state)) + inode_sub_bytes(inode, num_dec); + } + } + clear_len = num_dec; + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + /* + * we can't truncate inline items that have had + * special encodings + */ + if (!del_item && + btrfs_file_extent_encryption(leaf, fi) == 0 && + btrfs_file_extent_other_encoding(leaf, fi) == 0 && + btrfs_file_extent_compression(leaf, fi) == 0) { + u32 size = (u32)(new_size - found_key.offset); + + btrfs_set_file_extent_ram_bytes(leaf, fi, size); + size = btrfs_file_extent_calc_inline_size(size); + btrfs_truncate_item(path, size, 1); + } else if (!del_item) { + /* + * We have to bail so the last_size is set to + * just before this extent. + */ + ret = NEED_TRUNCATE_BLOCK; + break; + } else { + /* + * Inline extents are special, we just treat + * them as a full sector worth in the file + * extent tree just for simplicity sake. + */ + clear_len = fs_info->sectorsize; + } + + if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) + inode_sub_bytes(inode, item_end + 1 - new_size); + } +delete: + /* + * We use btrfs_truncate_inode_items() to clean up log trees for + * multiple fsyncs, and in this case we don't want to clear the + * file extent range because it's just the log. + */ + if (root == BTRFS_I(inode)->root) { + ret = btrfs_inode_clear_file_extent_range(BTRFS_I(inode), + clear_start, clear_len); + if (ret) { + btrfs_abort_transaction(trans, ret); + break; + } + } + + if (del_item) + last_size = found_key.offset; + else + last_size = new_size; + if (del_item) { + if (!pending_del_nr) { + /* no pending yet, add ourselves */ + pending_del_slot = path->slots[0]; + pending_del_nr = 1; + } else if (pending_del_nr && + path->slots[0] + 1 == pending_del_slot) { + /* hop on the pending chunk */ + pending_del_nr++; + pending_del_slot = path->slots[0]; + } else { + BUG(); + } + } else { + break; + } + should_throttle = false; + + if (found_extent && + root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { + struct btrfs_ref ref = { 0 }; + + bytes_deleted += extent_num_bytes; + + btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, + extent_start, extent_num_bytes, 0); + ref.real_root = root->root_key.objectid; + btrfs_init_data_ref(&ref, btrfs_header_owner(leaf), + ino, extent_offset); + ret = btrfs_free_extent(trans, &ref); + if (ret) { + btrfs_abort_transaction(trans, ret); + break; + } + if (be_nice) { + if (btrfs_should_throttle_delayed_refs(trans)) + should_throttle = true; + } + } + + if (found_type == BTRFS_INODE_ITEM_KEY) + break; + + if (path->slots[0] == 0 || + path->slots[0] != pending_del_slot || + should_throttle) { + if (pending_del_nr) { + ret = btrfs_del_items(trans, root, path, + pending_del_slot, + pending_del_nr); + if (ret) { + btrfs_abort_transaction(trans, ret); + break; + } + pending_del_nr = 0; + } + btrfs_release_path(path); + + /* + * We can generate a lot of delayed refs, so we need to + * throttle every once and a while and make sure we're + * adding enough space to keep up with the work we are + * generating. Since we hold a transaction here we + * can't flush, and we don't want to FLUSH_LIMIT because + * we could have generated too many delayed refs to + * actually allocate, so just bail if we're short and + * let the normal reservation dance happen higher up. + */ + if (should_throttle) { + ret = btrfs_delayed_refs_rsv_refill(fs_info, + BTRFS_RESERVE_NO_FLUSH); + if (ret) { + ret = -EAGAIN; + break; + } + } + goto search_again; + } else { + path->slots[0]--; + } + } +out: + if (ret >= 0 && pending_del_nr) { + int err; + + err = btrfs_del_items(trans, root, path, pending_del_slot, + pending_del_nr); + if (err) { + btrfs_abort_transaction(trans, err); + ret = err; + } + } + if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { + ASSERT(last_size >= new_size); + if (!ret && last_size > new_size) + last_size = new_size; + btrfs_inode_safe_disk_i_size_write(inode, last_size); + unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, + (u64)-1, &cached_state); + } + + btrfs_free_path(path); + return ret; +} + +/* + * btrfs_truncate_block - read, zero a chunk and write a block + * @inode - inode that we're zeroing + * @from - the offset to start zeroing + * @len - the length to zero, 0 to zero the entire range respective to the + * offset + * @front - zero up to the offset instead of from the offset on + * + * This will find the block for the "from" offset and cow the block and zero the + * part we want to zero. This is used with truncate and hole punching. + */ +int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len, + int front) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct address_space *mapping = inode->i_mapping; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + struct extent_changeset *data_reserved = NULL; + char *kaddr; + bool only_release_metadata = false; + u32 blocksize = fs_info->sectorsize; + pgoff_t index = from >> PAGE_SHIFT; + unsigned offset = from & (blocksize - 1); + struct page *page; + gfp_t mask = btrfs_alloc_write_mask(mapping); + size_t write_bytes = blocksize; + int ret = 0; + u64 block_start; + u64 block_end; + + if (IS_ALIGNED(offset, blocksize) && + (!len || IS_ALIGNED(len, blocksize))) + goto out; + + block_start = round_down(from, blocksize); + block_end = block_start + blocksize - 1; + + ret = btrfs_check_data_free_space(BTRFS_I(inode), &data_reserved, + block_start, blocksize); + if (ret < 0) { + if (btrfs_check_nocow_lock(BTRFS_I(inode), block_start, + &write_bytes) > 0) { + /* For nocow case, no need to reserve data space */ + only_release_metadata = true; + } else { + goto out; + } + } + ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), blocksize); + if (ret < 0) { + if (!only_release_metadata) + btrfs_free_reserved_data_space(BTRFS_I(inode), + data_reserved, block_start, blocksize); + goto out; + } +again: + page = find_or_create_page(mapping, index, mask); + if (!page) { + btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, + block_start, blocksize, true); + btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize); + ret = -ENOMEM; + goto out; + } + + if (!PageUptodate(page)) { + ret = btrfs_readpage(NULL, page); + lock_page(page); + if (page->mapping != mapping) { + unlock_page(page); + put_page(page); + goto again; + } + if (!PageUptodate(page)) { + ret = -EIO; + goto out_unlock; + } + } + wait_on_page_writeback(page); + + lock_extent_bits(io_tree, block_start, block_end, &cached_state); + set_page_extent_mapped(page); + + ordered = btrfs_lookup_ordered_extent(BTRFS_I(inode), block_start); + if (ordered) { + unlock_extent_cached(io_tree, block_start, block_end, + &cached_state); + unlock_page(page); + put_page(page); + btrfs_start_ordered_extent(ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end, + EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, + 0, 0, &cached_state); + + ret = btrfs_set_extent_delalloc(BTRFS_I(inode), block_start, block_end, 0, + &cached_state); + if (ret) { + unlock_extent_cached(io_tree, block_start, block_end, + &cached_state); + goto out_unlock; + } + + if (offset != blocksize) { + if (!len) + len = blocksize - offset; + kaddr = kmap(page); + if (front) + memset(kaddr + (block_start - page_offset(page)), + 0, offset); + else + memset(kaddr + (block_start - page_offset(page)) + offset, + 0, len); + flush_dcache_page(page); + kunmap(page); + } + ClearPageChecked(page); + set_page_dirty(page); + unlock_extent_cached(io_tree, block_start, block_end, &cached_state); + + if (only_release_metadata) + set_extent_bit(&BTRFS_I(inode)->io_tree, block_start, + block_end, EXTENT_NORESERVE, NULL, NULL, + GFP_NOFS); + +out_unlock: + if (ret) { + if (only_release_metadata) + btrfs_delalloc_release_metadata(BTRFS_I(inode), + blocksize, true); + else + btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, + block_start, blocksize, true); + } + btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize); + unlock_page(page); + put_page(page); +out: + if (only_release_metadata) + btrfs_check_nocow_unlock(BTRFS_I(inode)); + extent_changeset_free(data_reserved); + return ret; +} + +static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode, + u64 offset, u64 len) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_trans_handle *trans; + int ret; + + /* + * Still need to make sure the inode looks like it's been updated so + * that any holes get logged if we fsync. + */ + if (btrfs_fs_incompat(fs_info, NO_HOLES)) { + BTRFS_I(inode)->last_trans = fs_info->generation; + BTRFS_I(inode)->last_sub_trans = root->log_transid; + BTRFS_I(inode)->last_log_commit = root->last_log_commit; + return 0; + } + + /* + * 1 - for the one we're dropping + * 1 - for the one we're adding + * 1 - for updating the inode. + */ + trans = btrfs_start_transaction(root, 3); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1); + if (ret) { + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + return ret; + } + + ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)), + offset, 0, 0, len, 0, len, 0, 0, 0); + if (ret) + btrfs_abort_transaction(trans, ret); + else + btrfs_update_inode(trans, root, inode); + btrfs_end_transaction(trans); + return ret; +} + +/* + * This function puts in dummy file extents for the area we're creating a hole + * for. So if we are truncating this file to a larger size we need to insert + * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for + * the range between oldsize and size + */ +int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map *em = NULL; + struct extent_state *cached_state = NULL; + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + u64 hole_start = ALIGN(oldsize, fs_info->sectorsize); + u64 block_end = ALIGN(size, fs_info->sectorsize); + u64 last_byte; + u64 cur_offset; + u64 hole_size; + int err = 0; + + /* + * If our size started in the middle of a block we need to zero out the + * rest of the block before we expand the i_size, otherwise we could + * expose stale data. + */ + err = btrfs_truncate_block(inode, oldsize, 0, 0); + if (err) + return err; + + if (size <= hole_start) + return 0; + + btrfs_lock_and_flush_ordered_range(BTRFS_I(inode), hole_start, + block_end - 1, &cached_state); + cur_offset = hole_start; + while (1) { + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset, + block_end - cur_offset); + if (IS_ERR(em)) { + err = PTR_ERR(em); + em = NULL; + break; + } + last_byte = min(extent_map_end(em), block_end); + last_byte = ALIGN(last_byte, fs_info->sectorsize); + hole_size = last_byte - cur_offset; + + if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) { + struct extent_map *hole_em; + + err = maybe_insert_hole(root, inode, cur_offset, + hole_size); + if (err) + break; + + err = btrfs_inode_set_file_extent_range(BTRFS_I(inode), + cur_offset, hole_size); + if (err) + break; + + btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset, + cur_offset + hole_size - 1, 0); + hole_em = alloc_extent_map(); + if (!hole_em) { + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + goto next; + } + hole_em->start = cur_offset; + hole_em->len = hole_size; + hole_em->orig_start = cur_offset; + + hole_em->block_start = EXTENT_MAP_HOLE; + hole_em->block_len = 0; + hole_em->orig_block_len = 0; + hole_em->ram_bytes = hole_size; + hole_em->compress_type = BTRFS_COMPRESS_NONE; + hole_em->generation = fs_info->generation; + + while (1) { + write_lock(&em_tree->lock); + err = add_extent_mapping(em_tree, hole_em, 1); + write_unlock(&em_tree->lock); + if (err != -EEXIST) + break; + btrfs_drop_extent_cache(BTRFS_I(inode), + cur_offset, + cur_offset + + hole_size - 1, 0); + } + free_extent_map(hole_em); + } else { + err = btrfs_inode_set_file_extent_range(BTRFS_I(inode), + cur_offset, hole_size); + if (err) + break; + } +next: + free_extent_map(em); + em = NULL; + cur_offset = last_byte; + if (cur_offset >= block_end) + break; + } + free_extent_map(em); + unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state); + return err; +} + +static int btrfs_setsize(struct inode *inode, struct iattr *attr) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + loff_t oldsize = i_size_read(inode); + loff_t newsize = attr->ia_size; + int mask = attr->ia_valid; + int ret; + + /* + * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a + * special case where we need to update the times despite not having + * these flags set. For all other operations the VFS set these flags + * explicitly if it wants a timestamp update. + */ + if (newsize != oldsize) { + inode_inc_iversion(inode); + if (!(mask & (ATTR_CTIME | ATTR_MTIME))) + inode->i_ctime = inode->i_mtime = + current_time(inode); + } + + if (newsize > oldsize) { + /* + * Don't do an expanding truncate while snapshotting is ongoing. + * This is to ensure the snapshot captures a fully consistent + * state of this file - if the snapshot captures this expanding + * truncation, it must capture all writes that happened before + * this truncation. + */ + btrfs_drew_write_lock(&root->snapshot_lock); + ret = btrfs_cont_expand(inode, oldsize, newsize); + if (ret) { + btrfs_drew_write_unlock(&root->snapshot_lock); + return ret; + } + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + btrfs_drew_write_unlock(&root->snapshot_lock); + return PTR_ERR(trans); + } + + i_size_write(inode, newsize); + btrfs_inode_safe_disk_i_size_write(inode, 0); + pagecache_isize_extended(inode, oldsize, newsize); + ret = btrfs_update_inode(trans, root, inode); + btrfs_drew_write_unlock(&root->snapshot_lock); + btrfs_end_transaction(trans); + } else { + + /* + * We're truncating a file that used to have good data down to + * zero. Make sure any new writes to the file get on disk + * on close. + */ + if (newsize == 0) + set_bit(BTRFS_INODE_FLUSH_ON_CLOSE, + &BTRFS_I(inode)->runtime_flags); + + truncate_setsize(inode, newsize); + + inode_dio_wait(inode); + + ret = btrfs_truncate(inode, newsize == oldsize); + if (ret && inode->i_nlink) { + int err; + + /* + * Truncate failed, so fix up the in-memory size. We + * adjusted disk_i_size down as we removed extents, so + * wait for disk_i_size to be stable and then update the + * in-memory size to match. + */ + err = btrfs_wait_ordered_range(inode, 0, (u64)-1); + if (err) + return err; + i_size_write(inode, BTRFS_I(inode)->disk_i_size); + } + } + + return ret; +} + +static int btrfs_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = d_inode(dentry); + struct btrfs_root *root = BTRFS_I(inode)->root; + int err; + + if (btrfs_root_readonly(root)) + return -EROFS; + + err = setattr_prepare(dentry, attr); + if (err) + return err; + + if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) { + err = btrfs_setsize(inode, attr); + if (err) + return err; + } + + if (attr->ia_valid) { + setattr_copy(inode, attr); + inode_inc_iversion(inode); + err = btrfs_dirty_inode(inode); + + if (!err && attr->ia_valid & ATTR_MODE) + err = posix_acl_chmod(inode, inode->i_mode); + } + + return err; +} + +/* + * While truncating the inode pages during eviction, we get the VFS calling + * btrfs_invalidatepage() against each page of the inode. This is slow because + * the calls to btrfs_invalidatepage() result in a huge amount of calls to + * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting + * extent_state structures over and over, wasting lots of time. + * + * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all + * those expensive operations on a per page basis and do only the ordered io + * finishing, while we release here the extent_map and extent_state structures, + * without the excessive merging and splitting. + */ +static void evict_inode_truncate_pages(struct inode *inode) +{ + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree; + struct rb_node *node; + + ASSERT(inode->i_state & I_FREEING); + truncate_inode_pages_final(&inode->i_data); + + write_lock(&map_tree->lock); + while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) { + struct extent_map *em; + + node = rb_first_cached(&map_tree->map); + em = rb_entry(node, struct extent_map, rb_node); + clear_bit(EXTENT_FLAG_PINNED, &em->flags); + clear_bit(EXTENT_FLAG_LOGGING, &em->flags); + remove_extent_mapping(map_tree, em); + free_extent_map(em); + if (need_resched()) { + write_unlock(&map_tree->lock); + cond_resched(); + write_lock(&map_tree->lock); + } + } + write_unlock(&map_tree->lock); + + /* + * Keep looping until we have no more ranges in the io tree. + * We can have ongoing bios started by readahead that have + * their endio callback (extent_io.c:end_bio_extent_readpage) + * still in progress (unlocked the pages in the bio but did not yet + * unlocked the ranges in the io tree). Therefore this means some + * ranges can still be locked and eviction started because before + * submitting those bios, which are executed by a separate task (work + * queue kthread), inode references (inode->i_count) were not taken + * (which would be dropped in the end io callback of each bio). + * Therefore here we effectively end up waiting for those bios and + * anyone else holding locked ranges without having bumped the inode's + * reference count - if we don't do it, when they access the inode's + * io_tree to unlock a range it may be too late, leading to an + * use-after-free issue. + */ + spin_lock(&io_tree->lock); + while (!RB_EMPTY_ROOT(&io_tree->state)) { + struct extent_state *state; + struct extent_state *cached_state = NULL; + u64 start; + u64 end; + unsigned state_flags; + + node = rb_first(&io_tree->state); + state = rb_entry(node, struct extent_state, rb_node); + start = state->start; + end = state->end; + state_flags = state->state; + spin_unlock(&io_tree->lock); + + lock_extent_bits(io_tree, start, end, &cached_state); + + /* + * If still has DELALLOC flag, the extent didn't reach disk, + * and its reserved space won't be freed by delayed_ref. + * So we need to free its reserved space here. + * (Refer to comment in btrfs_invalidatepage, case 2) + * + * Note, end is the bytenr of last byte, so we need + 1 here. + */ + if (state_flags & EXTENT_DELALLOC) + btrfs_qgroup_free_data(BTRFS_I(inode), NULL, start, + end - start + 1); + + clear_extent_bit(io_tree, start, end, + EXTENT_LOCKED | EXTENT_DELALLOC | + EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1, + &cached_state); + + cond_resched(); + spin_lock(&io_tree->lock); + } + spin_unlock(&io_tree->lock); +} + +static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root, + struct btrfs_block_rsv *rsv) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + struct btrfs_trans_handle *trans; + u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1); + int ret; + + /* + * Eviction should be taking place at some place safe because of our + * delayed iputs. However the normal flushing code will run delayed + * iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock. + * + * We reserve the delayed_refs_extra here again because we can't use + * btrfs_start_transaction(root, 0) for the same deadlocky reason as + * above. We reserve our extra bit here because we generate a ton of + * delayed refs activity by truncating. + * + * If we cannot make our reservation we'll attempt to steal from the + * global reserve, because we really want to be able to free up space. + */ + ret = btrfs_block_rsv_refill(root, rsv, rsv->size + delayed_refs_extra, + BTRFS_RESERVE_FLUSH_EVICT); + if (ret) { + /* + * Try to steal from the global reserve if there is space for + * it. + */ + if (btrfs_check_space_for_delayed_refs(fs_info) || + btrfs_block_rsv_migrate(global_rsv, rsv, rsv->size, 0)) { + btrfs_warn(fs_info, + "could not allocate space for delete; will truncate on mount"); + return ERR_PTR(-ENOSPC); + } + delayed_refs_extra = 0; + } + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return trans; + + if (delayed_refs_extra) { + trans->block_rsv = &fs_info->trans_block_rsv; + trans->bytes_reserved = delayed_refs_extra; + btrfs_block_rsv_migrate(rsv, trans->block_rsv, + delayed_refs_extra, 1); + } + return trans; +} + +void btrfs_evict_inode(struct inode *inode) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *rsv; + int ret; + + trace_btrfs_inode_evict(inode); + + if (!root) { + clear_inode(inode); + return; + } + + evict_inode_truncate_pages(inode); + + if (inode->i_nlink && + ((btrfs_root_refs(&root->root_item) != 0 && + root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) || + btrfs_is_free_space_inode(BTRFS_I(inode)))) + goto no_delete; + + if (is_bad_inode(inode)) + goto no_delete; + + btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1); + + if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) + goto no_delete; + + if (inode->i_nlink > 0) { + BUG_ON(btrfs_root_refs(&root->root_item) != 0 && + root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID); + goto no_delete; + } + + ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode)); + if (ret) + goto no_delete; + + rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); + if (!rsv) + goto no_delete; + rsv->size = btrfs_calc_metadata_size(fs_info, 1); + rsv->failfast = 1; + + btrfs_i_size_write(BTRFS_I(inode), 0); + + while (1) { + trans = evict_refill_and_join(root, rsv); + if (IS_ERR(trans)) + goto free_rsv; + + trans->block_rsv = rsv; + + ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0); + trans->block_rsv = &fs_info->trans_block_rsv; + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(fs_info); + if (ret && ret != -ENOSPC && ret != -EAGAIN) + goto free_rsv; + else if (!ret) + break; + } + + /* + * Errors here aren't a big deal, it just means we leave orphan items in + * the tree. They will be cleaned up on the next mount. If the inode + * number gets reused, cleanup deletes the orphan item without doing + * anything, and unlink reuses the existing orphan item. + * + * If it turns out that we are dropping too many of these, we might want + * to add a mechanism for retrying these after a commit. + */ + trans = evict_refill_and_join(root, rsv); + if (!IS_ERR(trans)) { + trans->block_rsv = rsv; + btrfs_orphan_del(trans, BTRFS_I(inode)); + trans->block_rsv = &fs_info->trans_block_rsv; + btrfs_end_transaction(trans); + } + + if (!(root == fs_info->tree_root || + root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)) + btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode))); + +free_rsv: + btrfs_free_block_rsv(fs_info, rsv); +no_delete: + /* + * If we didn't successfully delete, the orphan item will still be in + * the tree and we'll retry on the next mount. Again, we might also want + * to retry these periodically in the future. + */ + btrfs_remove_delayed_node(BTRFS_I(inode)); + clear_inode(inode); +} + +/* + * Return the key found in the dir entry in the location pointer, fill @type + * with BTRFS_FT_*, and return 0. + * + * If no dir entries were found, returns -ENOENT. + * If found a corrupted location in dir entry, returns -EUCLEAN. + */ +static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry, + struct btrfs_key *location, u8 *type) +{ + const char *name = dentry->d_name.name; + int namelen = dentry->d_name.len; + struct btrfs_dir_item *di; + struct btrfs_path *path; + struct btrfs_root *root = BTRFS_I(dir)->root; + int ret = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)), + name, namelen, 0); + if (IS_ERR_OR_NULL(di)) { + ret = di ? PTR_ERR(di) : -ENOENT; + goto out; + } + + btrfs_dir_item_key_to_cpu(path->nodes[0], di, location); + if (location->type != BTRFS_INODE_ITEM_KEY && + location->type != BTRFS_ROOT_ITEM_KEY) { + ret = -EUCLEAN; + btrfs_warn(root->fs_info, +"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))", + __func__, name, btrfs_ino(BTRFS_I(dir)), + location->objectid, location->type, location->offset); + } + if (!ret) + *type = btrfs_dir_type(path->nodes[0], di); +out: + btrfs_free_path(path); + return ret; +} + +/* + * when we hit a tree root in a directory, the btrfs part of the inode + * needs to be changed to reflect the root directory of the tree root. This + * is kind of like crossing a mount point. + */ +static int fixup_tree_root_location(struct btrfs_fs_info *fs_info, + struct inode *dir, + struct dentry *dentry, + struct btrfs_key *location, + struct btrfs_root **sub_root) +{ + struct btrfs_path *path; + struct btrfs_root *new_root; + struct btrfs_root_ref *ref; + struct extent_buffer *leaf; + struct btrfs_key key; + int ret; + int err = 0; + + path = btrfs_alloc_path(); + if (!path) { + err = -ENOMEM; + goto out; + } + + err = -ENOENT; + key.objectid = BTRFS_I(dir)->root->root_key.objectid; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = location->objectid; + + ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0); + if (ret) { + if (ret < 0) + err = ret; + goto out; + } + + leaf = path->nodes[0]; + ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref); + if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) || + btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len) + goto out; + + ret = memcmp_extent_buffer(leaf, dentry->d_name.name, + (unsigned long)(ref + 1), + dentry->d_name.len); + if (ret) + goto out; + + btrfs_release_path(path); + + new_root = btrfs_get_fs_root(fs_info, location->objectid, true); + if (IS_ERR(new_root)) { + err = PTR_ERR(new_root); + goto out; + } + + *sub_root = new_root; + location->objectid = btrfs_root_dirid(&new_root->root_item); + location->type = BTRFS_INODE_ITEM_KEY; + location->offset = 0; + err = 0; +out: + btrfs_free_path(path); + return err; +} + +static void inode_tree_add(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_inode *entry; + struct rb_node **p; + struct rb_node *parent; + struct rb_node *new = &BTRFS_I(inode)->rb_node; + u64 ino = btrfs_ino(BTRFS_I(inode)); + + if (inode_unhashed(inode)) + return; + parent = NULL; + spin_lock(&root->inode_lock); + p = &root->inode_tree.rb_node; + while (*p) { + parent = *p; + entry = rb_entry(parent, struct btrfs_inode, rb_node); + + if (ino < btrfs_ino(entry)) + p = &parent->rb_left; + else if (ino > btrfs_ino(entry)) + p = &parent->rb_right; + else { + WARN_ON(!(entry->vfs_inode.i_state & + (I_WILL_FREE | I_FREEING))); + rb_replace_node(parent, new, &root->inode_tree); + RB_CLEAR_NODE(parent); + spin_unlock(&root->inode_lock); + return; + } + } + rb_link_node(new, parent, p); + rb_insert_color(new, &root->inode_tree); + spin_unlock(&root->inode_lock); +} + +static void inode_tree_del(struct btrfs_inode *inode) +{ + struct btrfs_root *root = inode->root; + int empty = 0; + + spin_lock(&root->inode_lock); + if (!RB_EMPTY_NODE(&inode->rb_node)) { + rb_erase(&inode->rb_node, &root->inode_tree); + RB_CLEAR_NODE(&inode->rb_node); + empty = RB_EMPTY_ROOT(&root->inode_tree); + } + spin_unlock(&root->inode_lock); + + if (empty && btrfs_root_refs(&root->root_item) == 0) { + spin_lock(&root->inode_lock); + empty = RB_EMPTY_ROOT(&root->inode_tree); + spin_unlock(&root->inode_lock); + if (empty) + btrfs_add_dead_root(root); + } +} + + +static int btrfs_init_locked_inode(struct inode *inode, void *p) +{ + struct btrfs_iget_args *args = p; + + inode->i_ino = args->ino; + BTRFS_I(inode)->location.objectid = args->ino; + BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; + BTRFS_I(inode)->location.offset = 0; + BTRFS_I(inode)->root = btrfs_grab_root(args->root); + BUG_ON(args->root && !BTRFS_I(inode)->root); + return 0; +} + +static int btrfs_find_actor(struct inode *inode, void *opaque) +{ + struct btrfs_iget_args *args = opaque; + + return args->ino == BTRFS_I(inode)->location.objectid && + args->root == BTRFS_I(inode)->root; +} + +static struct inode *btrfs_iget_locked(struct super_block *s, u64 ino, + struct btrfs_root *root) +{ + struct inode *inode; + struct btrfs_iget_args args; + unsigned long hashval = btrfs_inode_hash(ino, root); + + args.ino = ino; + args.root = root; + + inode = iget5_locked(s, hashval, btrfs_find_actor, + btrfs_init_locked_inode, + (void *)&args); + return inode; +} + +/* + * Get an inode object given its inode number and corresponding root. + * Path can be preallocated to prevent recursing back to iget through + * allocator. NULL is also valid but may require an additional allocation + * later. + */ +struct inode *btrfs_iget_path(struct super_block *s, u64 ino, + struct btrfs_root *root, struct btrfs_path *path) +{ + struct inode *inode; + + inode = btrfs_iget_locked(s, ino, root); + if (!inode) + return ERR_PTR(-ENOMEM); + + if (inode->i_state & I_NEW) { + int ret; + + ret = btrfs_read_locked_inode(inode, path); + if (!ret) { + inode_tree_add(inode); + unlock_new_inode(inode); + } else { + iget_failed(inode); + /* + * ret > 0 can come from btrfs_search_slot called by + * btrfs_read_locked_inode, this means the inode item + * was not found. + */ + if (ret > 0) + ret = -ENOENT; + inode = ERR_PTR(ret); + } + } + + return inode; +} + +struct inode *btrfs_iget(struct super_block *s, u64 ino, struct btrfs_root *root) +{ + return btrfs_iget_path(s, ino, root, NULL); +} + +static struct inode *new_simple_dir(struct super_block *s, + struct btrfs_key *key, + struct btrfs_root *root) +{ + struct inode *inode = new_inode(s); + + if (!inode) + return ERR_PTR(-ENOMEM); + + BTRFS_I(inode)->root = btrfs_grab_root(root); + memcpy(&BTRFS_I(inode)->location, key, sizeof(*key)); + set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags); + + inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID; + /* + * We only need lookup, the rest is read-only and there's no inode + * associated with the dentry + */ + inode->i_op = &simple_dir_inode_operations; + inode->i_opflags &= ~IOP_XATTR; + inode->i_fop = &simple_dir_operations; + inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO; + inode->i_mtime = current_time(inode); + inode->i_atime = inode->i_mtime; + inode->i_ctime = inode->i_mtime; + BTRFS_I(inode)->i_otime = inode->i_mtime; + + return inode; +} + +static inline u8 btrfs_inode_type(struct inode *inode) +{ + /* + * Compile-time asserts that generic FT_* types still match + * BTRFS_FT_* types + */ + BUILD_BUG_ON(BTRFS_FT_UNKNOWN != FT_UNKNOWN); + BUILD_BUG_ON(BTRFS_FT_REG_FILE != FT_REG_FILE); + BUILD_BUG_ON(BTRFS_FT_DIR != FT_DIR); + BUILD_BUG_ON(BTRFS_FT_CHRDEV != FT_CHRDEV); + BUILD_BUG_ON(BTRFS_FT_BLKDEV != FT_BLKDEV); + BUILD_BUG_ON(BTRFS_FT_FIFO != FT_FIFO); + BUILD_BUG_ON(BTRFS_FT_SOCK != FT_SOCK); + BUILD_BUG_ON(BTRFS_FT_SYMLINK != FT_SYMLINK); + + return fs_umode_to_ftype(inode->i_mode); +} + +struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); + struct inode *inode; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_root *sub_root = root; + struct btrfs_key location; + u8 di_type = 0; + int ret = 0; + + if (dentry->d_name.len > BTRFS_NAME_LEN) + return ERR_PTR(-ENAMETOOLONG); + + ret = btrfs_inode_by_name(dir, dentry, &location, &di_type); + if (ret < 0) + return ERR_PTR(ret); + + if (location.type == BTRFS_INODE_ITEM_KEY) { + inode = btrfs_iget(dir->i_sb, location.objectid, root); + if (IS_ERR(inode)) + return inode; + + /* Do extra check against inode mode with di_type */ + if (btrfs_inode_type(inode) != di_type) { + btrfs_crit(fs_info, +"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u", + inode->i_mode, btrfs_inode_type(inode), + di_type); + iput(inode); + return ERR_PTR(-EUCLEAN); + } + return inode; + } + + ret = fixup_tree_root_location(fs_info, dir, dentry, + &location, &sub_root); + if (ret < 0) { + if (ret != -ENOENT) + inode = ERR_PTR(ret); + else + inode = new_simple_dir(dir->i_sb, &location, sub_root); + } else { + inode = btrfs_iget(dir->i_sb, location.objectid, sub_root); + } + if (root != sub_root) + btrfs_put_root(sub_root); + + if (!IS_ERR(inode) && root != sub_root) { + down_read(&fs_info->cleanup_work_sem); + if (!sb_rdonly(inode->i_sb)) + ret = btrfs_orphan_cleanup(sub_root); + up_read(&fs_info->cleanup_work_sem); + if (ret) { + iput(inode); + inode = ERR_PTR(ret); + } + } + + return inode; +} + +static int btrfs_dentry_delete(const struct dentry *dentry) +{ + struct btrfs_root *root; + struct inode *inode = d_inode(dentry); + + if (!inode && !IS_ROOT(dentry)) + inode = d_inode(dentry->d_parent); + + if (inode) { + root = BTRFS_I(inode)->root; + if (btrfs_root_refs(&root->root_item) == 0) + return 1; + + if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) + return 1; + } + return 0; +} + +static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + struct inode *inode = btrfs_lookup_dentry(dir, dentry); + + if (inode == ERR_PTR(-ENOENT)) + inode = NULL; + return d_splice_alias(inode, dentry); +} + +/* + * All this infrastructure exists because dir_emit can fault, and we are holding + * the tree lock when doing readdir. For now just allocate a buffer and copy + * our information into that, and then dir_emit from the buffer. This is + * similar to what NFS does, only we don't keep the buffer around in pagecache + * because I'm afraid I'll mess that up. Long term we need to make filldir do + * copy_to_user_inatomic so we don't have to worry about page faulting under the + * tree lock. + */ +static int btrfs_opendir(struct inode *inode, struct file *file) +{ + struct btrfs_file_private *private; + + private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL); + if (!private) + return -ENOMEM; + private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); + if (!private->filldir_buf) { + kfree(private); + return -ENOMEM; + } + file->private_data = private; + return 0; +} + +struct dir_entry { + u64 ino; + u64 offset; + unsigned type; + int name_len; +}; + +static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx) +{ + while (entries--) { + struct dir_entry *entry = addr; + char *name = (char *)(entry + 1); + + ctx->pos = get_unaligned(&entry->offset); + if (!dir_emit(ctx, name, get_unaligned(&entry->name_len), + get_unaligned(&entry->ino), + get_unaligned(&entry->type))) + return 1; + addr += sizeof(struct dir_entry) + + get_unaligned(&entry->name_len); + ctx->pos++; + } + return 0; +} + +static int btrfs_real_readdir(struct file *file, struct dir_context *ctx) +{ + struct inode *inode = file_inode(file); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_file_private *private = file->private_data; + struct btrfs_dir_item *di; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_path *path; + void *addr; + struct list_head ins_list; + struct list_head del_list; + int ret; + struct extent_buffer *leaf; + int slot; + char *name_ptr; + int name_len; + int entries = 0; + int total_len = 0; + bool put = false; + struct btrfs_key location; + + if (!dir_emit_dots(file, ctx)) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + addr = private->filldir_buf; + path->reada = READA_FORWARD; + + INIT_LIST_HEAD(&ins_list); + INIT_LIST_HEAD(&del_list); + put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list); + +again: + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = ctx->pos; + key.objectid = btrfs_ino(BTRFS_I(inode)); + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto err; + + while (1) { + struct dir_entry *entry; + + leaf = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto err; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(leaf, &found_key, slot); + + if (found_key.objectid != key.objectid) + break; + if (found_key.type != BTRFS_DIR_INDEX_KEY) + break; + if (found_key.offset < ctx->pos) + goto next; + if (btrfs_should_delete_dir_index(&del_list, found_key.offset)) + goto next; + di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item); + name_len = btrfs_dir_name_len(leaf, di); + if ((total_len + sizeof(struct dir_entry) + name_len) >= + PAGE_SIZE) { + btrfs_release_path(path); + ret = btrfs_filldir(private->filldir_buf, entries, ctx); + if (ret) + goto nopos; + addr = private->filldir_buf; + entries = 0; + total_len = 0; + goto again; + } + + entry = addr; + put_unaligned(name_len, &entry->name_len); + name_ptr = (char *)(entry + 1); + read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1), + name_len); + put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)), + &entry->type); + btrfs_dir_item_key_to_cpu(leaf, di, &location); + put_unaligned(location.objectid, &entry->ino); + put_unaligned(found_key.offset, &entry->offset); + entries++; + addr += sizeof(struct dir_entry) + name_len; + total_len += sizeof(struct dir_entry) + name_len; +next: + path->slots[0]++; + } + btrfs_release_path(path); + + ret = btrfs_filldir(private->filldir_buf, entries, ctx); + if (ret) + goto nopos; + + ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list); + if (ret) + goto nopos; + + /* + * Stop new entries from being returned after we return the last + * entry. + * + * New directory entries are assigned a strictly increasing + * offset. This means that new entries created during readdir + * are *guaranteed* to be seen in the future by that readdir. + * This has broken buggy programs which operate on names as + * they're returned by readdir. Until we re-use freed offsets + * we have this hack to stop new entries from being returned + * under the assumption that they'll never reach this huge + * offset. + * + * This is being careful not to overflow 32bit loff_t unless the + * last entry requires it because doing so has broken 32bit apps + * in the past. + */ + if (ctx->pos >= INT_MAX) + ctx->pos = LLONG_MAX; + else + ctx->pos = INT_MAX; +nopos: + ret = 0; +err: + if (put) + btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list); + btrfs_free_path(path); + return ret; +} + +/* + * This is somewhat expensive, updating the tree every time the + * inode changes. But, it is most likely to find the inode in cache. + * FIXME, needs more benchmarking...there are no reasons other than performance + * to keep or drop this code. + */ +static int btrfs_dirty_inode(struct inode *inode) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_trans_handle *trans; + int ret; + + if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags)) + return 0; + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_update_inode(trans, root, inode); + if (ret && (ret == -ENOSPC || ret == -EDQUOT)) { + /* whoops, lets try again with the full transaction */ + btrfs_end_transaction(trans); + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_update_inode(trans, root, inode); + } + btrfs_end_transaction(trans); + if (BTRFS_I(inode)->delayed_node) + btrfs_balance_delayed_items(fs_info); + + return ret; +} + +/* + * This is a copy of file_update_time. We need this so we can return error on + * ENOSPC for updating the inode in the case of file write and mmap writes. + */ +static int btrfs_update_time(struct inode *inode, struct timespec64 *now, + int flags) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + bool dirty = flags & ~S_VERSION; + + if (btrfs_root_readonly(root)) + return -EROFS; + + if (flags & S_VERSION) + dirty |= inode_maybe_inc_iversion(inode, dirty); + if (flags & S_CTIME) + inode->i_ctime = *now; + if (flags & S_MTIME) + inode->i_mtime = *now; + if (flags & S_ATIME) + inode->i_atime = *now; + return dirty ? btrfs_dirty_inode(inode) : 0; +} + +/* + * find the highest existing sequence number in a directory + * and then set the in-memory index_cnt variable to reflect + * free sequence numbers + */ +static int btrfs_set_inode_index_count(struct btrfs_inode *inode) +{ + struct btrfs_root *root = inode->root; + struct btrfs_key key, found_key; + struct btrfs_path *path; + struct extent_buffer *leaf; + int ret; + + key.objectid = btrfs_ino(inode); + key.type = BTRFS_DIR_INDEX_KEY; + key.offset = (u64)-1; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + /* FIXME: we should be able to handle this */ + if (ret == 0) + goto out; + ret = 0; + + /* + * MAGIC NUMBER EXPLANATION: + * since we search a directory based on f_pos we have to start at 2 + * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody + * else has to start at 2 + */ + if (path->slots[0] == 0) { + inode->index_cnt = 2; + goto out; + } + + path->slots[0]--; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + if (found_key.objectid != btrfs_ino(inode) || + found_key.type != BTRFS_DIR_INDEX_KEY) { + inode->index_cnt = 2; + goto out; + } + + inode->index_cnt = found_key.offset + 1; +out: + btrfs_free_path(path); + return ret; +} + +/* + * helper to find a free sequence number in a given directory. This current + * code is very simple, later versions will do smarter things in the btree + */ +int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index) +{ + int ret = 0; + + if (dir->index_cnt == (u64)-1) { + ret = btrfs_inode_delayed_dir_index_count(dir); + if (ret) { + ret = btrfs_set_inode_index_count(dir); + if (ret) + return ret; + } + } + + *index = dir->index_cnt; + dir->index_cnt++; + + return ret; +} + +static int btrfs_insert_inode_locked(struct inode *inode) +{ + struct btrfs_iget_args args; + + args.ino = BTRFS_I(inode)->location.objectid; + args.root = BTRFS_I(inode)->root; + + return insert_inode_locked4(inode, + btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root), + btrfs_find_actor, &args); +} + +/* + * Inherit flags from the parent inode. + * + * Currently only the compression flags and the cow flags are inherited. + */ +static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir) +{ + unsigned int flags; + + if (!dir) + return; + + flags = BTRFS_I(dir)->flags; + + if (flags & BTRFS_INODE_NOCOMPRESS) { + BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS; + BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS; + } else if (flags & BTRFS_INODE_COMPRESS) { + BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS; + BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS; + } + + if (flags & BTRFS_INODE_NODATACOW) { + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW; + if (S_ISREG(inode->i_mode)) + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; + } + + btrfs_sync_inode_flags_to_i_flags(inode); +} + +static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, + const char *name, int name_len, + u64 ref_objectid, u64 objectid, + umode_t mode, u64 *index) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct inode *inode; + struct btrfs_inode_item *inode_item; + struct btrfs_key *location; + struct btrfs_path *path; + struct btrfs_inode_ref *ref; + struct btrfs_key key[2]; + u32 sizes[2]; + int nitems = name ? 2 : 1; + unsigned long ptr; + unsigned int nofs_flag; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return ERR_PTR(-ENOMEM); + + nofs_flag = memalloc_nofs_save(); + inode = new_inode(fs_info->sb); + memalloc_nofs_restore(nofs_flag); + if (!inode) { + btrfs_free_path(path); + return ERR_PTR(-ENOMEM); + } + + /* + * O_TMPFILE, set link count to 0, so that after this point, + * we fill in an inode item with the correct link count. + */ + if (!name) + set_nlink(inode, 0); + + /* + * we have to initialize this early, so we can reclaim the inode + * number if we fail afterwards in this function. + */ + inode->i_ino = objectid; + + if (dir && name) { + trace_btrfs_inode_request(dir); + + ret = btrfs_set_inode_index(BTRFS_I(dir), index); + if (ret) { + btrfs_free_path(path); + iput(inode); + return ERR_PTR(ret); + } + } else if (dir) { + *index = 0; + } + /* + * index_cnt is ignored for everything but a dir, + * btrfs_set_inode_index_count has an explanation for the magic + * number + */ + BTRFS_I(inode)->index_cnt = 2; + BTRFS_I(inode)->dir_index = *index; + BTRFS_I(inode)->root = btrfs_grab_root(root); + BTRFS_I(inode)->generation = trans->transid; + inode->i_generation = BTRFS_I(inode)->generation; + + /* + * We could have gotten an inode number from somebody who was fsynced + * and then removed in this same transaction, so let's just set full + * sync since it will be a full sync anyway and this will blow away the + * old info in the log. + */ + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); + + key[0].objectid = objectid; + key[0].type = BTRFS_INODE_ITEM_KEY; + key[0].offset = 0; + + sizes[0] = sizeof(struct btrfs_inode_item); + + if (name) { + /* + * Start new inodes with an inode_ref. This is slightly more + * efficient for small numbers of hard links since they will + * be packed into one item. Extended refs will kick in if we + * add more hard links than can fit in the ref item. + */ + key[1].objectid = objectid; + key[1].type = BTRFS_INODE_REF_KEY; + key[1].offset = ref_objectid; + + sizes[1] = name_len + sizeof(*ref); + } + + location = &BTRFS_I(inode)->location; + location->objectid = objectid; + location->offset = 0; + location->type = BTRFS_INODE_ITEM_KEY; + + ret = btrfs_insert_inode_locked(inode); + if (ret < 0) { + iput(inode); + goto fail; + } + + path->leave_spinning = 1; + ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems); + if (ret != 0) + goto fail_unlock; + + inode_init_owner(inode, dir, mode); + inode_set_bytes(inode, 0); + + inode->i_mtime = current_time(inode); + inode->i_atime = inode->i_mtime; + inode->i_ctime = inode->i_mtime; + BTRFS_I(inode)->i_otime = inode->i_mtime; + + inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_inode_item); + memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item, + sizeof(*inode_item)); + fill_inode_item(trans, path->nodes[0], inode_item, inode); + + if (name) { + ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, + struct btrfs_inode_ref); + btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len); + btrfs_set_inode_ref_index(path->nodes[0], ref, *index); + ptr = (unsigned long)(ref + 1); + write_extent_buffer(path->nodes[0], name, ptr, name_len); + } + + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_free_path(path); + + btrfs_inherit_iflags(inode, dir); + + if (S_ISREG(mode)) { + if (btrfs_test_opt(fs_info, NODATASUM)) + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM; + if (btrfs_test_opt(fs_info, NODATACOW)) + BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW | + BTRFS_INODE_NODATASUM; + } + + inode_tree_add(inode); + + trace_btrfs_inode_new(inode); + btrfs_set_inode_last_trans(trans, BTRFS_I(inode)); + + btrfs_update_root_times(trans, root); + + ret = btrfs_inode_inherit_props(trans, inode, dir); + if (ret) + btrfs_err(fs_info, + "error inheriting props for ino %llu (root %llu): %d", + btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret); + + return inode; + +fail_unlock: + discard_new_inode(inode); +fail: + if (dir && name) + BTRFS_I(dir)->index_cnt--; + btrfs_free_path(path); + return ERR_PTR(ret); +} + +/* + * utility function to add 'inode' into 'parent_inode' with + * a give name and a given sequence number. + * if 'add_backref' is true, also insert a backref from the + * inode to the parent directory. + */ +int btrfs_add_link(struct btrfs_trans_handle *trans, + struct btrfs_inode *parent_inode, struct btrfs_inode *inode, + const char *name, int name_len, int add_backref, u64 index) +{ + int ret = 0; + struct btrfs_key key; + struct btrfs_root *root = parent_inode->root; + u64 ino = btrfs_ino(inode); + u64 parent_ino = btrfs_ino(parent_inode); + + if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { + memcpy(&key, &inode->root->root_key, sizeof(key)); + } else { + key.objectid = ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + } + + if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { + ret = btrfs_add_root_ref(trans, key.objectid, + root->root_key.objectid, parent_ino, + index, name, name_len); + } else if (add_backref) { + ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino, + parent_ino, index); + } + + /* Nothing to clean up yet */ + if (ret) + return ret; + + ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key, + btrfs_inode_type(&inode->vfs_inode), index); + if (ret == -EEXIST || ret == -EOVERFLOW) + goto fail_dir_item; + else if (ret) { + btrfs_abort_transaction(trans, ret); + return ret; + } + + btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size + + name_len * 2); + inode_inc_iversion(&parent_inode->vfs_inode); + /* + * If we are replaying a log tree, we do not want to update the mtime + * and ctime of the parent directory with the current time, since the + * log replay procedure is responsible for setting them to their correct + * values (the ones it had when the fsync was done). + */ + if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) { + struct timespec64 now = current_time(&parent_inode->vfs_inode); + + parent_inode->vfs_inode.i_mtime = now; + parent_inode->vfs_inode.i_ctime = now; + } + ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode); + if (ret) + btrfs_abort_transaction(trans, ret); + return ret; + +fail_dir_item: + if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) { + u64 local_index; + int err; + err = btrfs_del_root_ref(trans, key.objectid, + root->root_key.objectid, parent_ino, + &local_index, name, name_len); + if (err) + btrfs_abort_transaction(trans, err); + } else if (add_backref) { + u64 local_index; + int err; + + err = btrfs_del_inode_ref(trans, root, name, name_len, + ino, parent_ino, &local_index); + if (err) + btrfs_abort_transaction(trans, err); + } + + /* Return the original error code */ + return ret; +} + +static int btrfs_add_nondir(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir, struct dentry *dentry, + struct btrfs_inode *inode, int backref, u64 index) +{ + int err = btrfs_add_link(trans, dir, inode, + dentry->d_name.name, dentry->d_name.len, + backref, index); + if (err > 0) + err = -EEXIST; + return err; +} + +static int btrfs_mknod(struct inode *dir, struct dentry *dentry, + umode_t mode, dev_t rdev) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + int err; + u64 objectid; + u64 index = 0; + + /* + * 2 for inode item and ref + * 2 for dir items + * 1 for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_objectid(root, &objectid); + if (err) + goto out_unlock; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid, + mode, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto out_unlock; + } + + /* + * If the active LSM wants to access the inode during + * d_instantiate it needs these. Smack checks to see + * if the filesystem supports xattrs by looking at the + * ops vector. + */ + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, rdev); + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_unlock; + + err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode), + 0, index); + if (err) + goto out_unlock; + + btrfs_update_inode(trans, root, inode); + d_instantiate_new(dentry, inode); + +out_unlock: + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(fs_info); + if (err && inode) { + inode_dec_link_count(inode); + discard_new_inode(inode); + } + return err; +} + +static int btrfs_create(struct inode *dir, struct dentry *dentry, + umode_t mode, bool excl) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + int err; + u64 objectid; + u64 index = 0; + + /* + * 2 for inode item and ref + * 2 for dir items + * 1 for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_objectid(root, &objectid); + if (err) + goto out_unlock; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid, + mode, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto out_unlock; + } + /* + * If the active LSM wants to access the inode during + * d_instantiate it needs these. Smack checks to see + * if the filesystem supports xattrs by looking at the + * ops vector. + */ + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + inode->i_mapping->a_ops = &btrfs_aops; + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_unlock; + + err = btrfs_update_inode(trans, root, inode); + if (err) + goto out_unlock; + + err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode), + 0, index); + if (err) + goto out_unlock; + + d_instantiate_new(dentry, inode); + +out_unlock: + btrfs_end_transaction(trans); + if (err && inode) { + inode_dec_link_count(inode); + discard_new_inode(inode); + } + btrfs_btree_balance_dirty(fs_info); + return err; +} + +static int btrfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + struct btrfs_trans_handle *trans = NULL; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = d_inode(old_dentry); + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + u64 index; + int err; + int drop_inode = 0; + + /* do not allow sys_link's with other subvols of the same device */ + if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid) + return -EXDEV; + + if (inode->i_nlink >= BTRFS_LINK_MAX) + return -EMLINK; + + err = btrfs_set_inode_index(BTRFS_I(dir), &index); + if (err) + goto fail; + + /* + * 2 items for inode and inode ref + * 2 items for dir items + * 1 item for parent inode + * 1 item for orphan item deletion if O_TMPFILE + */ + trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + trans = NULL; + goto fail; + } + + /* There are several dir indexes for this inode, clear the cache. */ + BTRFS_I(inode)->dir_index = 0ULL; + inc_nlink(inode); + inode_inc_iversion(inode); + inode->i_ctime = current_time(inode); + ihold(inode); + set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags); + + err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode), + 1, index); + + if (err) { + drop_inode = 1; + } else { + struct dentry *parent = dentry->d_parent; + + err = btrfs_update_inode(trans, root, inode); + if (err) + goto fail; + if (inode->i_nlink == 1) { + /* + * If new hard link count is 1, it's a file created + * with open(2) O_TMPFILE flag. + */ + err = btrfs_orphan_del(trans, BTRFS_I(inode)); + if (err) + goto fail; + } + d_instantiate(dentry, inode); + btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent); + } + +fail: + if (trans) + btrfs_end_transaction(trans); + if (drop_inode) { + inode_dec_link_count(inode); + iput(inode); + } + btrfs_btree_balance_dirty(fs_info); + return err; +} + +static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); + struct inode *inode = NULL; + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + int err = 0; + u64 objectid = 0; + u64 index = 0; + + /* + * 2 items for inode and ref + * 2 items for dir items + * 1 for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_objectid(root, &objectid); + if (err) + goto out_fail; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid, + S_IFDIR | mode, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto out_fail; + } + + /* these must be set before we unlock the inode */ + inode->i_op = &btrfs_dir_inode_operations; + inode->i_fop = &btrfs_dir_file_operations; + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_fail; + + btrfs_i_size_write(BTRFS_I(inode), 0); + err = btrfs_update_inode(trans, root, inode); + if (err) + goto out_fail; + + err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), + dentry->d_name.name, + dentry->d_name.len, 0, index); + if (err) + goto out_fail; + + d_instantiate_new(dentry, inode); + +out_fail: + btrfs_end_transaction(trans); + if (err && inode) { + inode_dec_link_count(inode); + discard_new_inode(inode); + } + btrfs_btree_balance_dirty(fs_info); + return err; +} + +static noinline int uncompress_inline(struct btrfs_path *path, + struct page *page, + size_t pg_offset, u64 extent_offset, + struct btrfs_file_extent_item *item) +{ + int ret; + struct extent_buffer *leaf = path->nodes[0]; + char *tmp; + size_t max_size; + unsigned long inline_size; + unsigned long ptr; + int compress_type; + + WARN_ON(pg_offset != 0); + compress_type = btrfs_file_extent_compression(leaf, item); + max_size = btrfs_file_extent_ram_bytes(leaf, item); + inline_size = btrfs_file_extent_inline_item_len(leaf, + btrfs_item_nr(path->slots[0])); + tmp = kmalloc(inline_size, GFP_NOFS); + if (!tmp) + return -ENOMEM; + ptr = btrfs_file_extent_inline_start(item); + + read_extent_buffer(leaf, tmp, ptr, inline_size); + + max_size = min_t(unsigned long, PAGE_SIZE, max_size); + ret = btrfs_decompress(compress_type, tmp, page, + extent_offset, inline_size, max_size); + + /* + * decompression code contains a memset to fill in any space between the end + * of the uncompressed data and the end of max_size in case the decompressed + * data ends up shorter than ram_bytes. That doesn't cover the hole between + * the end of an inline extent and the beginning of the next block, so we + * cover that region here. + */ + + if (max_size + pg_offset < PAGE_SIZE) { + char *map = kmap(page); + memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset); + kunmap(page); + } + kfree(tmp); + return ret; +} + +/** + * btrfs_get_extent - Lookup the first extent overlapping a range in a file. + * @inode: file to search in + * @page: page to read extent data into if the extent is inline + * @pg_offset: offset into @page to copy to + * @start: file offset + * @len: length of range starting at @start + * + * This returns the first &struct extent_map which overlaps with the given + * range, reading it from the B-tree and caching it if necessary. Note that + * there may be more extents which overlap the given range after the returned + * extent_map. + * + * If @page is not NULL and the extent is inline, this also reads the extent + * data directly into the page and marks the extent up to date in the io_tree. + * + * Return: ERR_PTR on error, non-NULL extent_map on success. + */ +struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, + struct page *page, size_t pg_offset, + u64 start, u64 len) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + int ret = 0; + u64 extent_start = 0; + u64 extent_end = 0; + u64 objectid = btrfs_ino(inode); + int extent_type = -1; + struct btrfs_path *path = NULL; + struct btrfs_root *root = inode->root; + struct btrfs_file_extent_item *item; + struct extent_buffer *leaf; + struct btrfs_key found_key; + struct extent_map *em = NULL; + struct extent_map_tree *em_tree = &inode->extent_tree; + struct extent_io_tree *io_tree = &inode->io_tree; + + read_lock(&em_tree->lock); + em = lookup_extent_mapping(em_tree, start, len); + read_unlock(&em_tree->lock); + + if (em) { + if (em->start > start || em->start + em->len <= start) + free_extent_map(em); + else if (em->block_start == EXTENT_MAP_INLINE && page) + free_extent_map(em); + else + goto out; + } + em = alloc_extent_map(); + if (!em) { + ret = -ENOMEM; + goto out; + } + em->start = EXTENT_MAP_HOLE; + em->orig_start = EXTENT_MAP_HOLE; + em->len = (u64)-1; + em->block_len = (u64)-1; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + /* Chances are we'll be called again, so go ahead and do readahead */ + path->reada = READA_FORWARD; + + /* + * Unless we're going to uncompress the inline extent, no sleep would + * happen. + */ + path->leave_spinning = 1; + + path->recurse = btrfs_is_free_space_inode(inode); + + ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0); + if (ret < 0) { + goto out; + } else if (ret > 0) { + if (path->slots[0] == 0) + goto not_found; + path->slots[0]--; + ret = 0; + } + + leaf = path->nodes[0]; + item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != objectid || + found_key.type != BTRFS_EXTENT_DATA_KEY) { + /* + * If we backup past the first extent we want to move forward + * and see if there is an extent in front of us, otherwise we'll + * say there is a hole for our whole search range which can + * cause problems. + */ + extent_end = start; + goto next; + } + + extent_type = btrfs_file_extent_type(leaf, item); + extent_start = found_key.offset; + extent_end = btrfs_file_extent_end(path); + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + /* Only regular file could have regular/prealloc extent */ + if (!S_ISREG(inode->vfs_inode.i_mode)) { + ret = -EUCLEAN; + btrfs_crit(fs_info, + "regular/prealloc extent found for non-regular inode %llu", + btrfs_ino(inode)); + goto out; + } + trace_btrfs_get_extent_show_fi_regular(inode, leaf, item, + extent_start); + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + trace_btrfs_get_extent_show_fi_inline(inode, leaf, item, + path->slots[0], + extent_start); + } +next: + if (start >= extent_end) { + path->slots[0]++; + if (path->slots[0] >= btrfs_header_nritems(leaf)) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + goto out; + else if (ret > 0) + goto not_found; + + leaf = path->nodes[0]; + } + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + if (found_key.objectid != objectid || + found_key.type != BTRFS_EXTENT_DATA_KEY) + goto not_found; + if (start + len <= found_key.offset) + goto not_found; + if (start > found_key.offset) + goto next; + + /* New extent overlaps with existing one */ + em->start = start; + em->orig_start = start; + em->len = found_key.offset - start; + em->block_start = EXTENT_MAP_HOLE; + goto insert; + } + + btrfs_extent_item_to_extent_map(inode, path, item, !page, em); + + if (extent_type == BTRFS_FILE_EXTENT_REG || + extent_type == BTRFS_FILE_EXTENT_PREALLOC) { + goto insert; + } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { + unsigned long ptr; + char *map; + size_t size; + size_t extent_offset; + size_t copy_size; + + if (!page) + goto out; + + size = btrfs_file_extent_ram_bytes(leaf, item); + extent_offset = page_offset(page) + pg_offset - extent_start; + copy_size = min_t(u64, PAGE_SIZE - pg_offset, + size - extent_offset); + em->start = extent_start + extent_offset; + em->len = ALIGN(copy_size, fs_info->sectorsize); + em->orig_block_len = em->len; + em->orig_start = em->start; + ptr = btrfs_file_extent_inline_start(item) + extent_offset; + + btrfs_set_path_blocking(path); + if (!PageUptodate(page)) { + if (btrfs_file_extent_compression(leaf, item) != + BTRFS_COMPRESS_NONE) { + ret = uncompress_inline(path, page, pg_offset, + extent_offset, item); + if (ret) + goto out; + } else { + map = kmap(page); + read_extent_buffer(leaf, map + pg_offset, ptr, + copy_size); + if (pg_offset + copy_size < PAGE_SIZE) { + memset(map + pg_offset + copy_size, 0, + PAGE_SIZE - pg_offset - + copy_size); + } + kunmap(page); + } + flush_dcache_page(page); + } + set_extent_uptodate(io_tree, em->start, + extent_map_end(em) - 1, NULL, GFP_NOFS); + goto insert; + } +not_found: + em->start = start; + em->orig_start = start; + em->len = len; + em->block_start = EXTENT_MAP_HOLE; +insert: + ret = 0; + btrfs_release_path(path); + if (em->start > start || extent_map_end(em) <= start) { + btrfs_err(fs_info, + "bad extent! em: [%llu %llu] passed [%llu %llu]", + em->start, em->len, start, len); + ret = -EIO; + goto out; + } + + write_lock(&em_tree->lock); + ret = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len); + write_unlock(&em_tree->lock); +out: + btrfs_free_path(path); + + trace_btrfs_get_extent(root, inode, em); + + if (ret) { + free_extent_map(em); + return ERR_PTR(ret); + } + return em; +} + +struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode, + u64 start, u64 len) +{ + struct extent_map *em; + struct extent_map *hole_em = NULL; + u64 delalloc_start = start; + u64 end; + u64 delalloc_len; + u64 delalloc_end; + int err = 0; + + em = btrfs_get_extent(inode, NULL, 0, start, len); + if (IS_ERR(em)) + return em; + /* + * If our em maps to: + * - a hole or + * - a pre-alloc extent, + * there might actually be delalloc bytes behind it. + */ + if (em->block_start != EXTENT_MAP_HOLE && + !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + return em; + else + hole_em = em; + + /* check to see if we've wrapped (len == -1 or similar) */ + end = start + len; + if (end < start) + end = (u64)-1; + else + end -= 1; + + em = NULL; + + /* ok, we didn't find anything, lets look for delalloc */ + delalloc_len = count_range_bits(&inode->io_tree, &delalloc_start, + end, len, EXTENT_DELALLOC, 1); + delalloc_end = delalloc_start + delalloc_len; + if (delalloc_end < delalloc_start) + delalloc_end = (u64)-1; + + /* + * We didn't find anything useful, return the original results from + * get_extent() + */ + if (delalloc_start > end || delalloc_end <= start) { + em = hole_em; + hole_em = NULL; + goto out; + } + + /* + * Adjust the delalloc_start to make sure it doesn't go backwards from + * the start they passed in + */ + delalloc_start = max(start, delalloc_start); + delalloc_len = delalloc_end - delalloc_start; + + if (delalloc_len > 0) { + u64 hole_start; + u64 hole_len; + const u64 hole_end = extent_map_end(hole_em); + + em = alloc_extent_map(); + if (!em) { + err = -ENOMEM; + goto out; + } + + ASSERT(hole_em); + /* + * When btrfs_get_extent can't find anything it returns one + * huge hole + * + * Make sure what it found really fits our range, and adjust to + * make sure it is based on the start from the caller + */ + if (hole_end <= start || hole_em->start > end) { + free_extent_map(hole_em); + hole_em = NULL; + } else { + hole_start = max(hole_em->start, start); + hole_len = hole_end - hole_start; + } + + if (hole_em && delalloc_start > hole_start) { + /* + * Our hole starts before our delalloc, so we have to + * return just the parts of the hole that go until the + * delalloc starts + */ + em->len = min(hole_len, delalloc_start - hole_start); + em->start = hole_start; + em->orig_start = hole_start; + /* + * Don't adjust block start at all, it is fixed at + * EXTENT_MAP_HOLE + */ + em->block_start = hole_em->block_start; + em->block_len = hole_len; + if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags)) + set_bit(EXTENT_FLAG_PREALLOC, &em->flags); + } else { + /* + * Hole is out of passed range or it starts after + * delalloc range + */ + em->start = delalloc_start; + em->len = delalloc_len; + em->orig_start = delalloc_start; + em->block_start = EXTENT_MAP_DELALLOC; + em->block_len = delalloc_len; + } + } else { + return hole_em; + } +out: + + free_extent_map(hole_em); + if (err) { + free_extent_map(em); + return ERR_PTR(err); + } + return em; +} + +static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode, + const u64 start, + const u64 len, + const u64 orig_start, + const u64 block_start, + const u64 block_len, + const u64 orig_block_len, + const u64 ram_bytes, + const int type) +{ + struct extent_map *em = NULL; + int ret; + + if (type != BTRFS_ORDERED_NOCOW) { + em = create_io_em(inode, start, len, orig_start, block_start, + block_len, orig_block_len, ram_bytes, + BTRFS_COMPRESS_NONE, /* compress_type */ + type); + if (IS_ERR(em)) + goto out; + } + ret = btrfs_add_ordered_extent_dio(inode, start, block_start, len, + block_len, type); + if (ret) { + if (em) { + free_extent_map(em); + btrfs_drop_extent_cache(inode, start, start + len - 1, 0); + } + em = ERR_PTR(ret); + } + out: + + return em; +} + +static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode, + u64 start, u64 len) +{ + struct btrfs_root *root = inode->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct extent_map *em; + struct btrfs_key ins; + u64 alloc_hint; + int ret; + + alloc_hint = get_extent_allocation_hint(inode, start, len); + ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize, + 0, alloc_hint, &ins, 1, 1); + if (ret) + return ERR_PTR(ret); + + em = btrfs_create_dio_extent(inode, start, ins.offset, start, + ins.objectid, ins.offset, ins.offset, + ins.offset, BTRFS_ORDERED_REGULAR); + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + if (IS_ERR(em)) + btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, + 1); + + return em; +} + +/* + * Check if we can do nocow write into the range [@offset, @offset + @len) + * + * @offset: File offset + * @len: The length to write, will be updated to the nocow writeable + * range + * @orig_start: (optional) Return the original file offset of the file extent + * @orig_len: (optional) Return the original on-disk length of the file extent + * @ram_bytes: (optional) Return the ram_bytes of the file extent + * @strict: if true, omit optimizations that might force us into unnecessary + * cow. e.g., don't trust generation number. + * + * This function will flush ordered extents in the range to ensure proper + * nocow checks for (nowait == false) case. + * + * Return: + * >0 and update @len if we can do nocow write + * 0 if we can't do nocow write + * <0 if error happened + * + * NOTE: This only checks the file extents, caller is responsible to wait for + * any ordered extents. + */ +noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len, + u64 *orig_start, u64 *orig_block_len, + u64 *ram_bytes, bool strict) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_path *path; + int ret; + struct extent_buffer *leaf; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_file_extent_item *fi; + struct btrfs_key key; + u64 disk_bytenr; + u64 backref_offset; + u64 extent_end; + u64 num_bytes; + int slot; + int found_type; + bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_lookup_file_extent(NULL, root, path, + btrfs_ino(BTRFS_I(inode)), offset, 0); + if (ret < 0) + goto out; + + slot = path->slots[0]; + if (ret == 1) { + if (slot == 0) { + /* can't find the item, must cow */ + ret = 0; + goto out; + } + slot--; + } + ret = 0; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, slot); + if (key.objectid != btrfs_ino(BTRFS_I(inode)) || + key.type != BTRFS_EXTENT_DATA_KEY) { + /* not our file or wrong item type, must cow */ + goto out; + } + + if (key.offset > offset) { + /* Wrong offset, must cow */ + goto out; + } + + fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); + found_type = btrfs_file_extent_type(leaf, fi); + if (found_type != BTRFS_FILE_EXTENT_REG && + found_type != BTRFS_FILE_EXTENT_PREALLOC) { + /* not a regular extent, must cow */ + goto out; + } + + if (!nocow && found_type == BTRFS_FILE_EXTENT_REG) + goto out; + + extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); + if (extent_end <= offset) + goto out; + + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); + if (disk_bytenr == 0) + goto out; + + if (btrfs_file_extent_compression(leaf, fi) || + btrfs_file_extent_encryption(leaf, fi) || + btrfs_file_extent_other_encoding(leaf, fi)) + goto out; + + /* + * Do the same check as in btrfs_cross_ref_exist but without the + * unnecessary search. + */ + if (!strict && + (btrfs_file_extent_generation(leaf, fi) <= + btrfs_root_last_snapshot(&root->root_item))) + goto out; + + backref_offset = btrfs_file_extent_offset(leaf, fi); + + if (orig_start) { + *orig_start = key.offset - backref_offset; + *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi); + *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); + } + + if (btrfs_extent_readonly(fs_info, disk_bytenr)) + goto out; + + num_bytes = min(offset + *len, extent_end) - offset; + if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) { + u64 range_end; + + range_end = round_up(offset + num_bytes, + root->fs_info->sectorsize) - 1; + ret = test_range_bit(io_tree, offset, range_end, + EXTENT_DELALLOC, 0, NULL); + if (ret) { + ret = -EAGAIN; + goto out; + } + } + + btrfs_release_path(path); + + /* + * look for other files referencing this extent, if we + * find any we must cow + */ + + ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)), + key.offset - backref_offset, disk_bytenr, + strict); + if (ret) { + ret = 0; + goto out; + } + + /* + * adjust disk_bytenr and num_bytes to cover just the bytes + * in this extent we are about to write. If there + * are any csums in that range we have to cow in order + * to keep the csums correct + */ + disk_bytenr += backref_offset; + disk_bytenr += offset - key.offset; + if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes)) + goto out; + /* + * all of the above have passed, it is safe to overwrite this extent + * without cow + */ + *len = num_bytes; + ret = 1; +out: + btrfs_free_path(path); + return ret; +} + +static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend, + struct extent_state **cached_state, bool writing) +{ + struct btrfs_ordered_extent *ordered; + int ret = 0; + + while (1) { + lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, + cached_state); + /* + * We're concerned with the entire range that we're going to be + * doing DIO to, so we need to make sure there's no ordered + * extents in this range. + */ + ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart, + lockend - lockstart + 1); + + /* + * We need to make sure there are no buffered pages in this + * range either, we could have raced between the invalidate in + * generic_file_direct_write and locking the extent. The + * invalidate needs to happen so that reads after a write do not + * get stale data. + */ + if (!ordered && + (!writing || !filemap_range_has_page(inode->i_mapping, + lockstart, lockend))) + break; + + unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, + cached_state); + + if (ordered) { + /* + * If we are doing a DIO read and the ordered extent we + * found is for a buffered write, we can not wait for it + * to complete and retry, because if we do so we can + * deadlock with concurrent buffered writes on page + * locks. This happens only if our DIO read covers more + * than one extent map, if at this point has already + * created an ordered extent for a previous extent map + * and locked its range in the inode's io tree, and a + * concurrent write against that previous extent map's + * range and this range started (we unlock the ranges + * in the io tree only when the bios complete and + * buffered writes always lock pages before attempting + * to lock range in the io tree). + */ + if (writing || + test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags)) + btrfs_start_ordered_extent(ordered, 1); + else + ret = -ENOTBLK; + btrfs_put_ordered_extent(ordered); + } else { + /* + * We could trigger writeback for this range (and wait + * for it to complete) and then invalidate the pages for + * this range (through invalidate_inode_pages2_range()), + * but that can lead us to a deadlock with a concurrent + * call to readahead (a buffered read or a defrag call + * triggered a readahead) on a page lock due to an + * ordered dio extent we created before but did not have + * yet a corresponding bio submitted (whence it can not + * complete), which makes readahead wait for that + * ordered extent to complete while holding a lock on + * that page. + */ + ret = -ENOTBLK; + } + + if (ret) + break; + + cond_resched(); + } + + return ret; +} + +/* The callers of this must take lock_extent() */ +static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start, + u64 len, u64 orig_start, u64 block_start, + u64 block_len, u64 orig_block_len, + u64 ram_bytes, int compress_type, + int type) +{ + struct extent_map_tree *em_tree; + struct extent_map *em; + int ret; + + ASSERT(type == BTRFS_ORDERED_PREALLOC || + type == BTRFS_ORDERED_COMPRESSED || + type == BTRFS_ORDERED_NOCOW || + type == BTRFS_ORDERED_REGULAR); + + em_tree = &inode->extent_tree; + em = alloc_extent_map(); + if (!em) + return ERR_PTR(-ENOMEM); + + em->start = start; + em->orig_start = orig_start; + em->len = len; + em->block_len = block_len; + em->block_start = block_start; + em->orig_block_len = orig_block_len; + em->ram_bytes = ram_bytes; + em->generation = -1; + set_bit(EXTENT_FLAG_PINNED, &em->flags); + if (type == BTRFS_ORDERED_PREALLOC) { + set_bit(EXTENT_FLAG_FILLING, &em->flags); + } else if (type == BTRFS_ORDERED_COMPRESSED) { + set_bit(EXTENT_FLAG_COMPRESSED, &em->flags); + em->compress_type = compress_type; + } + + do { + btrfs_drop_extent_cache(inode, em->start, + em->start + em->len - 1, 0); + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + /* + * The caller has taken lock_extent(), who could race with us + * to add em? + */ + } while (ret == -EEXIST); + + if (ret) { + free_extent_map(em); + return ERR_PTR(ret); + } + + /* em got 2 refs now, callers needs to do free_extent_map once. */ + return em; +} + + +static int btrfs_get_blocks_direct_write(struct extent_map **map, + struct inode *inode, + struct btrfs_dio_data *dio_data, + u64 start, u64 len) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct extent_map *em = *map; + int ret = 0; + + /* + * We don't allocate a new extent in the following cases + * + * 1) The inode is marked as NODATACOW. In this case we'll just use the + * existing extent. + * 2) The extent is marked as PREALLOC. We're good to go here and can + * just use the extent. + * + */ + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) || + ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) && + em->block_start != EXTENT_MAP_HOLE)) { + int type; + u64 block_start, orig_start, orig_block_len, ram_bytes; + + if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) + type = BTRFS_ORDERED_PREALLOC; + else + type = BTRFS_ORDERED_NOCOW; + len = min(len, em->len - (start - em->start)); + block_start = em->block_start + (start - em->start); + + if (can_nocow_extent(inode, start, &len, &orig_start, + &orig_block_len, &ram_bytes, false) == 1 && + btrfs_inc_nocow_writers(fs_info, block_start)) { + struct extent_map *em2; + + em2 = btrfs_create_dio_extent(BTRFS_I(inode), start, len, + orig_start, block_start, + len, orig_block_len, + ram_bytes, type); + btrfs_dec_nocow_writers(fs_info, block_start); + if (type == BTRFS_ORDERED_PREALLOC) { + free_extent_map(em); + *map = em = em2; + } + + if (em2 && IS_ERR(em2)) { + ret = PTR_ERR(em2); + goto out; + } + /* + * For inode marked NODATACOW or extent marked PREALLOC, + * use the existing or preallocated extent, so does not + * need to adjust btrfs_space_info's bytes_may_use. + */ + btrfs_free_reserved_data_space_noquota(fs_info, len); + goto skip_cow; + } + } + + /* this will cow the extent */ + free_extent_map(em); + *map = em = btrfs_new_extent_direct(BTRFS_I(inode), start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto out; + } + + len = min(len, em->len - (start - em->start)); + +skip_cow: + /* + * Need to update the i_size under the extent lock so buffered + * readers will get the updated i_size when we unlock. + */ + if (start + len > i_size_read(inode)) + i_size_write(inode, start + len); + + dio_data->reserve -= len; +out: + return ret; +} + +static int btrfs_dio_iomap_begin(struct inode *inode, loff_t start, + loff_t length, unsigned int flags, struct iomap *iomap, + struct iomap *srcmap) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct extent_map *em; + struct extent_state *cached_state = NULL; + struct btrfs_dio_data *dio_data = NULL; + u64 lockstart, lockend; + const bool write = !!(flags & IOMAP_WRITE); + int ret = 0; + u64 len = length; + bool unlock_extents = false; + bool sync = (current->journal_info == BTRFS_DIO_SYNC_STUB); + + /* + * We used current->journal_info here to see if we were sync, but + * there's a lot of tests in the enospc machinery to not do flushing if + * we have a journal_info set, so we need to clear this out and re-set + * it in iomap_end. + */ + ASSERT(current->journal_info == NULL || + current->journal_info == BTRFS_DIO_SYNC_STUB); + current->journal_info = NULL; + + if (!write) + len = min_t(u64, len, fs_info->sectorsize); + + lockstart = start; + lockend = start + len - 1; + + /* + * The generic stuff only does filemap_write_and_wait_range, which + * isn't enough if we've written compressed pages to this area, so we + * need to flush the dirty pages again to make absolutely sure that any + * outstanding dirty pages are on disk. + */ + if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) { + ret = filemap_fdatawrite_range(inode->i_mapping, start, + start + length - 1); + if (ret) + return ret; + } + + dio_data = kzalloc(sizeof(*dio_data), GFP_NOFS); + if (!dio_data) + return -ENOMEM; + + dio_data->sync = sync; + dio_data->length = length; + if (write) { + dio_data->reserve = round_up(length, fs_info->sectorsize); + ret = btrfs_delalloc_reserve_space(BTRFS_I(inode), + &dio_data->data_reserved, + start, dio_data->reserve); + if (ret) { + extent_changeset_free(dio_data->data_reserved); + kfree(dio_data); + return ret; + } + } + iomap->private = dio_data; + + + /* + * If this errors out it's because we couldn't invalidate pagecache for + * this range and we need to fallback to buffered. + */ + if (lock_extent_direct(inode, lockstart, lockend, &cached_state, write)) { + ret = -ENOTBLK; + goto err; + } + + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto unlock_err; + } + + /* + * Ok for INLINE and COMPRESSED extents we need to fallback on buffered + * io. INLINE is special, and we could probably kludge it in here, but + * it's still buffered so for safety lets just fall back to the generic + * buffered path. + * + * For COMPRESSED we _have_ to read the entire extent in so we can + * decompress it, so there will be buffering required no matter what we + * do, so go ahead and fallback to buffered. + * + * We return -ENOTBLK because that's what makes DIO go ahead and go back + * to buffered IO. Don't blame me, this is the price we pay for using + * the generic code. + */ + if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) || + em->block_start == EXTENT_MAP_INLINE) { + free_extent_map(em); + /* + * If we are in a NOWAIT context, return -EAGAIN in order to + * fallback to buffered IO. This is not only because we can + * block with buffered IO (no support for NOWAIT semantics at + * the moment) but also to avoid returning short reads to user + * space - this happens if we were able to read some data from + * previous non-compressed extents and then when we fallback to + * buffered IO, at btrfs_file_read_iter() by calling + * filemap_read(), we fail to fault in pages for the read buffer, + * in which case filemap_read() returns a short read (the number + * of bytes previously read is > 0, so it does not return -EFAULT). + */ + ret = (flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOTBLK; + goto unlock_err; + } + + len = min(len, em->len - (start - em->start)); + if (write) { + ret = btrfs_get_blocks_direct_write(&em, inode, dio_data, + start, len); + if (ret < 0) + goto unlock_err; + unlock_extents = true; + /* Recalc len in case the new em is smaller than requested */ + len = min(len, em->len - (start - em->start)); + } else { + /* + * We need to unlock only the end area that we aren't using. + * The rest is going to be unlocked by the endio routine. + */ + lockstart = start + len; + if (lockstart < lockend) + unlock_extents = true; + } + + if (unlock_extents) + unlock_extent_cached(&BTRFS_I(inode)->io_tree, + lockstart, lockend, &cached_state); + else + free_extent_state(cached_state); + + /* + * Translate extent map information to iomap. + * We trim the extents (and move the addr) even though iomap code does + * that, since we have locked only the parts we are performing I/O in. + */ + if ((em->block_start == EXTENT_MAP_HOLE) || + (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) && !write)) { + iomap->addr = IOMAP_NULL_ADDR; + iomap->type = IOMAP_HOLE; + } else { + iomap->addr = em->block_start + (start - em->start); + iomap->type = IOMAP_MAPPED; + } + iomap->offset = start; + iomap->bdev = fs_info->fs_devices->latest_bdev; + iomap->length = len; + + free_extent_map(em); + + return 0; + +unlock_err: + unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, + &cached_state); +err: + if (dio_data) { + btrfs_delalloc_release_space(BTRFS_I(inode), + dio_data->data_reserved, start, + dio_data->reserve, true); + btrfs_delalloc_release_extents(BTRFS_I(inode), dio_data->reserve); + extent_changeset_free(dio_data->data_reserved); + kfree(dio_data); + } + return ret; +} + +static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, + ssize_t written, unsigned int flags, struct iomap *iomap) +{ + int ret = 0; + struct btrfs_dio_data *dio_data = iomap->private; + size_t submitted = dio_data->submitted; + const bool write = !!(flags & IOMAP_WRITE); + + if (!write && (iomap->type == IOMAP_HOLE)) { + /* If reading from a hole, unlock and return */ + unlock_extent(&BTRFS_I(inode)->io_tree, pos, pos + length - 1); + goto out; + } + + if (submitted < length) { + pos += submitted; + length -= submitted; + if (write) + __endio_write_update_ordered(BTRFS_I(inode), pos, + length, false); + else + unlock_extent(&BTRFS_I(inode)->io_tree, pos, + pos + length - 1); + ret = -ENOTBLK; + } + + if (write) { + if (dio_data->reserve) + btrfs_delalloc_release_space(BTRFS_I(inode), + dio_data->data_reserved, pos, + dio_data->reserve, true); + btrfs_delalloc_release_extents(BTRFS_I(inode), dio_data->length); + extent_changeset_free(dio_data->data_reserved); + } +out: + /* + * We're all done, we can re-set the current->journal_info now safely + * for our endio. + */ + if (dio_data->sync) { + ASSERT(current->journal_info == NULL); + current->journal_info = BTRFS_DIO_SYNC_STUB; + } + kfree(dio_data); + iomap->private = NULL; + + return ret; +} + +static void btrfs_dio_private_put(struct btrfs_dio_private *dip) +{ + /* + * This implies a barrier so that stores to dio_bio->bi_status before + * this and loads of dio_bio->bi_status after this are fully ordered. + */ + if (!refcount_dec_and_test(&dip->refs)) + return; + + if (bio_op(dip->dio_bio) == REQ_OP_WRITE) { + __endio_write_update_ordered(BTRFS_I(dip->inode), + dip->logical_offset, + dip->bytes, + !dip->dio_bio->bi_status); + } else { + unlock_extent(&BTRFS_I(dip->inode)->io_tree, + dip->logical_offset, + dip->logical_offset + dip->bytes - 1); + } + + bio_endio(dip->dio_bio); + kfree(dip); +} + +static blk_status_t submit_dio_repair_bio(struct inode *inode, struct bio *bio, + int mirror_num, + unsigned long bio_flags) +{ + struct btrfs_dio_private *dip = bio->bi_private; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + blk_status_t ret; + + BUG_ON(bio_op(bio) == REQ_OP_WRITE); + + ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); + if (ret) + return ret; + + refcount_inc(&dip->refs); + ret = btrfs_map_bio(fs_info, bio, mirror_num); + if (ret) + refcount_dec(&dip->refs); + return ret; +} + +static blk_status_t btrfs_check_read_dio_bio(struct inode *inode, + struct btrfs_io_bio *io_bio, + const bool uptodate) +{ + struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; + const u32 sectorsize = fs_info->sectorsize; + struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM); + struct bio_vec bvec; + struct bvec_iter iter; + u64 start = io_bio->logical; + int icsum = 0; + blk_status_t err = BLK_STS_OK; + + __bio_for_each_segment(bvec, &io_bio->bio, iter, io_bio->iter) { + unsigned int i, nr_sectors, pgoff; + + nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len); + pgoff = bvec.bv_offset; + for (i = 0; i < nr_sectors; i++) { + ASSERT(pgoff < PAGE_SIZE); + if (uptodate && + (!csum || !check_data_csum(inode, io_bio, icsum, + bvec.bv_page, pgoff, + start, sectorsize))) { + clean_io_failure(fs_info, failure_tree, io_tree, + start, bvec.bv_page, + btrfs_ino(BTRFS_I(inode)), + pgoff); + } else { + blk_status_t status; + + status = btrfs_submit_read_repair(inode, + &io_bio->bio, + start - io_bio->logical, + bvec.bv_page, pgoff, + start, + start + sectorsize - 1, + io_bio->mirror_num, + submit_dio_repair_bio); + if (status) + err = status; + } + start += sectorsize; + icsum++; + pgoff += sectorsize; + } + } + return err; +} + +static void __endio_write_update_ordered(struct btrfs_inode *inode, + const u64 offset, const u64 bytes, + const bool uptodate) +{ + struct btrfs_fs_info *fs_info = inode->root->fs_info; + struct btrfs_ordered_extent *ordered = NULL; + struct btrfs_workqueue *wq; + u64 ordered_offset = offset; + u64 ordered_bytes = bytes; + u64 last_offset; + + if (btrfs_is_free_space_inode(inode)) + wq = fs_info->endio_freespace_worker; + else + wq = fs_info->endio_write_workers; + + while (ordered_offset < offset + bytes) { + last_offset = ordered_offset; + if (btrfs_dec_test_first_ordered_pending(inode, &ordered, + &ordered_offset, + ordered_bytes, + uptodate)) { + btrfs_init_work(&ordered->work, finish_ordered_fn, NULL, + NULL); + btrfs_queue_work(wq, &ordered->work); + } + /* + * If btrfs_dec_test_ordered_pending does not find any ordered + * extent in the range, we can exit. + */ + if (ordered_offset == last_offset) + return; + /* + * Our bio might span multiple ordered extents. In this case + * we keep going until we have accounted the whole dio. + */ + if (ordered_offset < offset + bytes) { + ordered_bytes = offset + bytes - ordered_offset; + ordered = NULL; + } + } +} + +static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data, + struct bio *bio, u64 offset) +{ + struct inode *inode = private_data; + + return btrfs_csum_one_bio(BTRFS_I(inode), bio, offset, 1); +} + +static void btrfs_end_dio_bio(struct bio *bio) +{ + struct btrfs_dio_private *dip = bio->bi_private; + blk_status_t err = bio->bi_status; + + if (err) + btrfs_warn(BTRFS_I(dip->inode)->root->fs_info, + "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d", + btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio), + bio->bi_opf, + (unsigned long long)bio->bi_iter.bi_sector, + bio->bi_iter.bi_size, err); + + if (bio_op(bio) == REQ_OP_READ) { + err = btrfs_check_read_dio_bio(dip->inode, btrfs_io_bio(bio), + !err); + } + + if (err) + dip->dio_bio->bi_status = err; + + bio_put(bio); + btrfs_dio_private_put(dip); +} + +static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio, + struct inode *inode, u64 file_offset, int async_submit) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_dio_private *dip = bio->bi_private; + bool write = bio_op(bio) == REQ_OP_WRITE; + blk_status_t ret; + + /* Check btrfs_submit_bio_hook() for rules about async submit. */ + if (async_submit) + async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers); + + if (!write) { + ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA); + if (ret) + goto err; + } + + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) + goto map; + + if (write && async_submit) { + ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0, + file_offset, inode, + btrfs_submit_bio_start_direct_io); + goto err; + } else if (write) { + /* + * If we aren't doing async submit, calculate the csum of the + * bio now. + */ + ret = btrfs_csum_one_bio(BTRFS_I(inode), bio, file_offset, 1); + if (ret) + goto err; + } else { + u64 csum_offset; + + csum_offset = file_offset - dip->logical_offset; + csum_offset >>= inode->i_sb->s_blocksize_bits; + csum_offset *= btrfs_super_csum_size(fs_info->super_copy); + btrfs_io_bio(bio)->csum = dip->csums + csum_offset; + } +map: + ret = btrfs_map_bio(fs_info, bio, 0); +err: + return ret; +} + +/* + * If this succeeds, the btrfs_dio_private is responsible for cleaning up locked + * or ordered extents whether or not we submit any bios. + */ +static struct btrfs_dio_private *btrfs_create_dio_private(struct bio *dio_bio, + struct inode *inode, + loff_t file_offset) +{ + const bool write = (bio_op(dio_bio) == REQ_OP_WRITE); + const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM); + size_t dip_size; + struct btrfs_dio_private *dip; + + dip_size = sizeof(*dip); + if (!write && csum) { + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + const u16 csum_size = btrfs_super_csum_size(fs_info->super_copy); + size_t nblocks; + + nblocks = dio_bio->bi_iter.bi_size >> inode->i_sb->s_blocksize_bits; + dip_size += csum_size * nblocks; + } + + dip = kzalloc(dip_size, GFP_NOFS); + if (!dip) + return NULL; + + dip->inode = inode; + dip->logical_offset = file_offset; + dip->bytes = dio_bio->bi_iter.bi_size; + dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9; + dip->dio_bio = dio_bio; + refcount_set(&dip->refs, 1); + return dip; +} + +static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap, + struct bio *dio_bio, loff_t file_offset) +{ + const bool write = (bio_op(dio_bio) == REQ_OP_WRITE); + const bool csum = !(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM); + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + const bool raid56 = (btrfs_data_alloc_profile(fs_info) & + BTRFS_BLOCK_GROUP_RAID56_MASK); + struct btrfs_dio_private *dip; + struct bio *bio; + u64 start_sector; + int async_submit = 0; + u64 submit_len; + int clone_offset = 0; + int clone_len; + int ret; + blk_status_t status; + struct btrfs_io_geometry geom; + struct btrfs_dio_data *dio_data = iomap->private; + + dip = btrfs_create_dio_private(dio_bio, inode, file_offset); + if (!dip) { + if (!write) { + unlock_extent(&BTRFS_I(inode)->io_tree, file_offset, + file_offset + dio_bio->bi_iter.bi_size - 1); + } + dio_bio->bi_status = BLK_STS_RESOURCE; + bio_endio(dio_bio); + return BLK_QC_T_NONE; + } + + if (!write && csum) { + /* + * Load the csums up front to reduce csum tree searches and + * contention when submitting bios. + */ + status = btrfs_lookup_bio_sums(inode, dio_bio, file_offset, + dip->csums); + if (status != BLK_STS_OK) + goto out_err; + } + + start_sector = dio_bio->bi_iter.bi_sector; + submit_len = dio_bio->bi_iter.bi_size; + + do { + ret = btrfs_get_io_geometry(fs_info, btrfs_op(dio_bio), + start_sector << 9, submit_len, + &geom); + if (ret) { + status = errno_to_blk_status(ret); + goto out_err; + } + ASSERT(geom.len <= INT_MAX); + + clone_len = min_t(int, submit_len, geom.len); + + /* + * This will never fail as it's passing GPF_NOFS and + * the allocation is backed by btrfs_bioset. + */ + bio = btrfs_bio_clone_partial(dio_bio, clone_offset, clone_len); + bio->bi_private = dip; + bio->bi_end_io = btrfs_end_dio_bio; + btrfs_io_bio(bio)->logical = file_offset; + + ASSERT(submit_len >= clone_len); + submit_len -= clone_len; + + /* + * Increase the count before we submit the bio so we know + * the end IO handler won't happen before we increase the + * count. Otherwise, the dip might get freed before we're + * done setting it up. + * + * We transfer the initial reference to the last bio, so we + * don't need to increment the reference count for the last one. + */ + if (submit_len > 0) { + refcount_inc(&dip->refs); + /* + * If we are submitting more than one bio, submit them + * all asynchronously. The exception is RAID 5 or 6, as + * asynchronous checksums make it difficult to collect + * full stripe writes. + */ + if (!raid56) + async_submit = 1; + } + + status = btrfs_submit_dio_bio(bio, inode, file_offset, + async_submit); + if (status) { + bio_put(bio); + if (submit_len > 0) + refcount_dec(&dip->refs); + goto out_err; + } + + dio_data->submitted += clone_len; + clone_offset += clone_len; + start_sector += clone_len >> 9; + file_offset += clone_len; + } while (submit_len > 0); + return BLK_QC_T_NONE; + +out_err: + dip->dio_bio->bi_status = status; + btrfs_dio_private_put(dip); + return BLK_QC_T_NONE; +} + +static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info, + const struct iov_iter *iter, loff_t offset) +{ + int seg; + int i; + unsigned int blocksize_mask = fs_info->sectorsize - 1; + ssize_t retval = -EINVAL; + + if (offset & blocksize_mask) + goto out; + + if (iov_iter_alignment(iter) & blocksize_mask) + goto out; + + /* If this is a write we don't need to check anymore */ + if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter)) + return 0; + /* + * Check to make sure we don't have duplicate iov_base's in this + * iovec, if so return EINVAL, otherwise we'll get csum errors + * when reading back. + */ + for (seg = 0; seg < iter->nr_segs; seg++) { + for (i = seg + 1; i < iter->nr_segs; i++) { + if (iter->iov[seg].iov_base == iter->iov[i].iov_base) + goto out; + } + } + retval = 0; +out: + return retval; +} + +static inline int btrfs_maybe_fsync_end_io(struct kiocb *iocb, ssize_t size, + int error, unsigned flags) +{ + /* + * Now if we're still in the context of our submitter we know we can't + * safely run generic_write_sync(), so clear our flag here so that the + * caller knows to follow up with a sync. + */ + if (current->journal_info == BTRFS_DIO_SYNC_STUB) { + current->journal_info = NULL; + return error; + } + + if (error) + return error; + + if (size) { + iocb->ki_flags |= IOCB_DSYNC; + return generic_write_sync(iocb, size); + } + + return 0; +} + +static const struct iomap_ops btrfs_dio_iomap_ops = { + .iomap_begin = btrfs_dio_iomap_begin, + .iomap_end = btrfs_dio_iomap_end, +}; + +static const struct iomap_dio_ops btrfs_dio_ops = { + .submit_io = btrfs_submit_direct, +}; + +static const struct iomap_dio_ops btrfs_sync_dops = { + .submit_io = btrfs_submit_direct, + .end_io = btrfs_maybe_fsync_end_io, +}; + +ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct extent_changeset *data_reserved = NULL; + loff_t offset = iocb->ki_pos; + size_t count = 0; + bool relock = false; + ssize_t ret; + + if (check_direct_IO(fs_info, iter, offset)) { + ASSERT(current->journal_info == NULL || + current->journal_info == BTRFS_DIO_SYNC_STUB); + current->journal_info = NULL; + return 0; + } + + count = iov_iter_count(iter); + if (iov_iter_rw(iter) == WRITE) { + /* + * If the write DIO is beyond the EOF, we need update + * the isize, but it is protected by i_mutex. So we can + * not unlock the i_mutex at this case. + */ + if (offset + count <= inode->i_size) { + inode_unlock(inode); + relock = true; + } + down_read(&BTRFS_I(inode)->dio_sem); + } + + /* + * We have are actually a sync iocb, so we need our fancy endio to know + * if we need to sync. + */ + if (current->journal_info) + ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, + &btrfs_sync_dops, is_sync_kiocb(iocb)); + else + ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, + &btrfs_dio_ops, is_sync_kiocb(iocb)); + + if (ret == -ENOTBLK) + ret = 0; + + if (iov_iter_rw(iter) == WRITE) + up_read(&BTRFS_I(inode)->dio_sem); + + if (relock) + inode_lock(inode); + + extent_changeset_free(data_reserved); + return ret; +} + +static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, + u64 start, u64 len) +{ + int ret; + + ret = fiemap_prep(inode, fieinfo, start, &len, 0); + if (ret) + return ret; + + return extent_fiemap(BTRFS_I(inode), fieinfo, start, len); +} + +int btrfs_readpage(struct file *file, struct page *page) +{ + struct btrfs_inode *inode = BTRFS_I(page->mapping->host); + u64 start = page_offset(page); + u64 end = start + PAGE_SIZE - 1; + unsigned long bio_flags = 0; + struct bio *bio = NULL; + int ret; + + btrfs_lock_and_flush_ordered_range(inode, start, end, NULL); + + ret = btrfs_do_readpage(page, NULL, &bio, &bio_flags, 0, NULL); + if (bio) + ret = submit_one_bio(bio, 0, bio_flags); + return ret; +} + +static int btrfs_writepage(struct page *page, struct writeback_control *wbc) +{ + struct inode *inode = page->mapping->host; + int ret; + + if (current->flags & PF_MEMALLOC) { + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return 0; + } + + /* + * If we are under memory pressure we will call this directly from the + * VM, we need to make sure we have the inode referenced for the ordered + * extent. If not just return like we didn't do anything. + */ + if (!igrab(inode)) { + redirty_page_for_writepage(wbc, page); + return AOP_WRITEPAGE_ACTIVATE; + } + ret = extent_write_full_page(page, wbc); + btrfs_add_delayed_iput(inode); + return ret; +} + +static int btrfs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + return extent_writepages(mapping, wbc); +} + +static void btrfs_readahead(struct readahead_control *rac) +{ + extent_readahead(rac); +} + +static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) +{ + int ret = try_release_extent_mapping(page, gfp_flags); + if (ret == 1) + detach_page_private(page); + return ret; +} + +static int btrfs_releasepage(struct page *page, gfp_t gfp_flags) +{ + if (PageWriteback(page) || PageDirty(page)) + return 0; + return __btrfs_releasepage(page, gfp_flags); +} + +#ifdef CONFIG_MIGRATION +static int btrfs_migratepage(struct address_space *mapping, + struct page *newpage, struct page *page, + enum migrate_mode mode) +{ + int ret; + + ret = migrate_page_move_mapping(mapping, newpage, page, 0); + if (ret != MIGRATEPAGE_SUCCESS) + return ret; + + if (page_has_private(page)) + attach_page_private(newpage, detach_page_private(page)); + + if (PagePrivate2(page)) { + ClearPagePrivate2(page); + SetPagePrivate2(newpage); + } + + if (mode != MIGRATE_SYNC_NO_COPY) + migrate_page_copy(newpage, page); + else + migrate_page_states(newpage, page); + return MIGRATEPAGE_SUCCESS; +} +#endif + +static void btrfs_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + struct btrfs_inode *inode = BTRFS_I(page->mapping->host); + struct extent_io_tree *tree = &inode->io_tree; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + u64 page_start = page_offset(page); + u64 page_end = page_start + PAGE_SIZE - 1; + u64 start; + u64 end; + int inode_evicting = inode->vfs_inode.i_state & I_FREEING; + + /* + * we have the page locked, so new writeback can't start, + * and the dirty bit won't be cleared while we are here. + * + * Wait for IO on this page so that we can safely clear + * the PagePrivate2 bit and do ordered accounting + */ + wait_on_page_writeback(page); + + /* + * For subpage case, we have call sites like + * btrfs_punch_hole_lock_range() which passes range not aligned to + * sectorsize. + * If the range doesn't cover the full page, we don't need to and + * shouldn't clear page extent mapped, as page->private can still + * record subpage dirty bits for other part of the range. + * + * For cases that can invalidate the full even the range doesn't + * cover the full page, like invalidating the last page, we're + * still safe to wait for ordered extent to finish. + */ + if (!(offset == 0 && length == PAGE_SIZE)) { + btrfs_releasepage(page, GFP_NOFS); + return; + } + + if (!inode_evicting) + lock_extent_bits(tree, page_start, page_end, &cached_state); + + start = page_start; +again: + ordered = btrfs_lookup_ordered_range(inode, start, page_end - start + 1); + if (ordered) { + end = min(page_end, + ordered->file_offset + ordered->num_bytes - 1); + /* + * IO on this page will never be started, so we need + * to account for any ordered extents now + */ + if (!inode_evicting) + clear_extent_bit(tree, start, end, + EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | + EXTENT_LOCKED | EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, 1, 0, &cached_state); + /* + * whoever cleared the private bit is responsible + * for the finish_ordered_io + */ + if (TestClearPagePrivate2(page)) { + struct btrfs_ordered_inode_tree *tree; + u64 new_len; + + tree = &inode->ordered_tree; + + spin_lock_irq(&tree->lock); + set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags); + new_len = start - ordered->file_offset; + if (new_len < ordered->truncated_len) + ordered->truncated_len = new_len; + spin_unlock_irq(&tree->lock); + + if (btrfs_dec_test_ordered_pending(inode, &ordered, + start, + end - start + 1, 1)) + btrfs_finish_ordered_io(ordered); + } + btrfs_put_ordered_extent(ordered); + if (!inode_evicting) { + cached_state = NULL; + lock_extent_bits(tree, start, end, + &cached_state); + } + + start = end + 1; + if (start < page_end) + goto again; + } + + /* + * Qgroup reserved space handler + * Page here will be either + * 1) Already written to disk or ordered extent already submitted + * Then its QGROUP_RESERVED bit in io_tree is already cleaned. + * Qgroup will be handled by its qgroup_record then. + * btrfs_qgroup_free_data() call will do nothing here. + * + * 2) Not written to disk yet + * Then btrfs_qgroup_free_data() call will clear the QGROUP_RESERVED + * bit of its io_tree, and free the qgroup reserved data space. + * Since the IO will never happen for this page. + */ + btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE); + if (!inode_evicting) { + clear_extent_bit(tree, page_start, page_end, EXTENT_LOCKED | + EXTENT_DELALLOC | EXTENT_DELALLOC_NEW | + EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1, + &cached_state); + + __btrfs_releasepage(page, GFP_NOFS); + } + + ClearPageChecked(page); + detach_page_private(page); +} + +/* + * btrfs_page_mkwrite() is not allowed to change the file size as it gets + * called from a page fault handler when a page is first dirtied. Hence we must + * be careful to check for EOF conditions here. We set the page up correctly + * for a written page which means we get ENOSPC checking when writing into + * holes and correct delalloc and unwritten extent mapping on filesystems that + * support these features. + * + * We are not allowed to take the i_mutex here so we have to play games to + * protect against truncate races as the page could now be beyond EOF. Because + * truncate_setsize() writes the inode size before removing pages, once we have + * the page lock we can determine safely if the page is beyond EOF. If it is not + * beyond EOF, then the page is guaranteed safe against truncation until we + * unlock the page. + */ +vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) +{ + struct page *page = vmf->page; + struct inode *inode = file_inode(vmf->vma->vm_file); + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct btrfs_ordered_extent *ordered; + struct extent_state *cached_state = NULL; + struct extent_changeset *data_reserved = NULL; + char *kaddr; + unsigned long zero_start; + loff_t size; + vm_fault_t ret; + int ret2; + int reserved = 0; + u64 reserved_space; + u64 page_start; + u64 page_end; + u64 end; + + reserved_space = PAGE_SIZE; + + sb_start_pagefault(inode->i_sb); + page_start = page_offset(page); + page_end = page_start + PAGE_SIZE - 1; + end = page_end; + + /* + * Reserving delalloc space after obtaining the page lock can lead to + * deadlock. For example, if a dirty page is locked by this function + * and the call to btrfs_delalloc_reserve_space() ends up triggering + * dirty page write out, then the btrfs_writepage() function could + * end up waiting indefinitely to get a lock on the page currently + * being processed by btrfs_page_mkwrite() function. + */ + ret2 = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved, + page_start, reserved_space); + if (!ret2) { + ret2 = file_update_time(vmf->vma->vm_file); + reserved = 1; + } + if (ret2) { + ret = vmf_error(ret2); + if (reserved) + goto out; + goto out_noreserve; + } + + ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */ +again: + lock_page(page); + size = i_size_read(inode); + + if ((page->mapping != inode->i_mapping) || + (page_start >= size)) { + /* page got truncated out from underneath us */ + goto out_unlock; + } + wait_on_page_writeback(page); + + lock_extent_bits(io_tree, page_start, page_end, &cached_state); + set_page_extent_mapped(page); + + /* + * we can't set the delalloc bits if there are pending ordered + * extents. Drop our locks and wait for them to finish + */ + ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start, + PAGE_SIZE); + if (ordered) { + unlock_extent_cached(io_tree, page_start, page_end, + &cached_state); + unlock_page(page); + btrfs_start_ordered_extent(ordered, 1); + btrfs_put_ordered_extent(ordered); + goto again; + } + + if (page->index == ((size - 1) >> PAGE_SHIFT)) { + reserved_space = round_up(size - page_start, + fs_info->sectorsize); + if (reserved_space < PAGE_SIZE) { + end = page_start + reserved_space - 1; + btrfs_delalloc_release_space(BTRFS_I(inode), + data_reserved, page_start, + PAGE_SIZE - reserved_space, true); + } + } + + /* + * page_mkwrite gets called when the page is firstly dirtied after it's + * faulted in, but write(2) could also dirty a page and set delalloc + * bits, thus in this case for space account reason, we still need to + * clear any delalloc bits within this page range since we have to + * reserve data&meta space before lock_page() (see above comments). + */ + clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end, + EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | + EXTENT_DEFRAG, 0, 0, &cached_state); + + ret2 = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, end, 0, + &cached_state); + if (ret2) { + unlock_extent_cached(io_tree, page_start, page_end, + &cached_state); + ret = VM_FAULT_SIGBUS; + goto out_unlock; + } + + /* page is wholly or partially inside EOF */ + if (page_start + PAGE_SIZE > size) + zero_start = offset_in_page(size); + else + zero_start = PAGE_SIZE; + + if (zero_start != PAGE_SIZE) { + kaddr = kmap(page); + memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start); + flush_dcache_page(page); + kunmap(page); + } + ClearPageChecked(page); + set_page_dirty(page); + SetPageUptodate(page); + + btrfs_set_inode_last_sub_trans(BTRFS_I(inode)); + + unlock_extent_cached(io_tree, page_start, page_end, &cached_state); + + btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); + sb_end_pagefault(inode->i_sb); + extent_changeset_free(data_reserved); + return VM_FAULT_LOCKED; + +out_unlock: + unlock_page(page); +out: + btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); + btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start, + reserved_space, (ret != 0)); +out_noreserve: + sb_end_pagefault(inode->i_sb); + extent_changeset_free(data_reserved); + return ret; +} + +static int btrfs_truncate(struct inode *inode, bool skip_writeback) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *rsv; + int ret; + struct btrfs_trans_handle *trans; + u64 mask = fs_info->sectorsize - 1; + u64 min_size = btrfs_calc_metadata_size(fs_info, 1); + + if (!skip_writeback) { + ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask), + (u64)-1); + if (ret) + return ret; + } + + /* + * Yes ladies and gentlemen, this is indeed ugly. We have a couple of + * things going on here: + * + * 1) We need to reserve space to update our inode. + * + * 2) We need to have something to cache all the space that is going to + * be free'd up by the truncate operation, but also have some slack + * space reserved in case it uses space during the truncate (thank you + * very much snapshotting). + * + * And we need these to be separate. The fact is we can use a lot of + * space doing the truncate, and we have no earthly idea how much space + * we will use, so we need the truncate reservation to be separate so it + * doesn't end up using space reserved for updating the inode. We also + * need to be able to stop the transaction and start a new one, which + * means we need to be able to update the inode several times, and we + * have no idea of knowing how many times that will be, so we can't just + * reserve 1 item for the entirety of the operation, so that has to be + * done separately as well. + * + * So that leaves us with + * + * 1) rsv - for the truncate reservation, which we will steal from the + * transaction reservation. + * 2) fs_info->trans_block_rsv - this will have 1 items worth left for + * updating the inode. + */ + rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); + if (!rsv) + return -ENOMEM; + rsv->size = min_size; + rsv->failfast = 1; + + /* + * 1 for the truncate slack space + * 1 for updating the inode. + */ + trans = btrfs_start_transaction(root, 2); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + + /* Migrate the slack space for the truncate to our reserve */ + ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, + min_size, false); + BUG_ON(ret); + + /* + * So if we truncate and then write and fsync we normally would just + * write the extents that changed, which is a problem if we need to + * first truncate that entire inode. So set this flag so we write out + * all of the extents in the inode to the sync log so we're completely + * safe. + */ + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags); + trans->block_rsv = rsv; + + while (1) { + ret = btrfs_truncate_inode_items(trans, root, inode, + inode->i_size, + BTRFS_EXTENT_DATA_KEY); + trans->block_rsv = &fs_info->trans_block_rsv; + if (ret != -ENOSPC && ret != -EAGAIN) + break; + + ret = btrfs_update_inode(trans, root, inode); + if (ret) + break; + + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(fs_info); + + trans = btrfs_start_transaction(root, 2); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + break; + } + + btrfs_block_rsv_release(fs_info, rsv, -1, NULL); + ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, + rsv, min_size, false); + BUG_ON(ret); /* shouldn't happen */ + trans->block_rsv = rsv; + } + + /* + * We can't call btrfs_truncate_block inside a trans handle as we could + * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know + * we've truncated everything except the last little bit, and can do + * btrfs_truncate_block and then update the disk_i_size. + */ + if (ret == NEED_TRUNCATE_BLOCK) { + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(fs_info); + + ret = btrfs_truncate_block(inode, inode->i_size, 0, 0); + if (ret) + goto out; + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + btrfs_inode_safe_disk_i_size_write(inode, 0); + } + + if (trans) { + int ret2; + + trans->block_rsv = &fs_info->trans_block_rsv; + ret2 = btrfs_update_inode(trans, root, inode); + if (ret2 && !ret) + ret = ret2; + + ret2 = btrfs_end_transaction(trans); + if (ret2 && !ret) + ret = ret2; + btrfs_btree_balance_dirty(fs_info); + } +out: + btrfs_free_block_rsv(fs_info, rsv); + + return ret; +} + +/* + * create a new subvolume directory/inode (helper for the ioctl). + */ +int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, + struct btrfs_root *new_root, + struct btrfs_root *parent_root, + u64 new_dirid) +{ + struct inode *inode; + int err; + u64 index = 0; + + inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, + new_dirid, new_dirid, + S_IFDIR | (~current_umask() & S_IRWXUGO), + &index); + if (IS_ERR(inode)) + return PTR_ERR(inode); + inode->i_op = &btrfs_dir_inode_operations; + inode->i_fop = &btrfs_dir_file_operations; + + set_nlink(inode, 1); + btrfs_i_size_write(BTRFS_I(inode), 0); + unlock_new_inode(inode); + + err = btrfs_subvol_inherit_props(trans, new_root, parent_root); + if (err) + btrfs_err(new_root->fs_info, + "error inheriting subvolume %llu properties: %d", + new_root->root_key.objectid, err); + + err = btrfs_update_inode(trans, new_root, inode); + + iput(inode); + return err; +} + +struct inode *btrfs_alloc_inode(struct super_block *sb) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(sb); + struct btrfs_inode *ei; + struct inode *inode; + + ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL); + if (!ei) + return NULL; + + ei->root = NULL; + ei->generation = 0; + ei->last_trans = 0; + ei->last_sub_trans = 0; + ei->logged_trans = 0; + ei->delalloc_bytes = 0; + ei->new_delalloc_bytes = 0; + ei->defrag_bytes = 0; + ei->disk_i_size = 0; + ei->flags = 0; + ei->csum_bytes = 0; + ei->index_cnt = (u64)-1; + ei->dir_index = 0; + ei->last_unlink_trans = 0; + ei->last_reflink_trans = 0; + ei->last_log_commit = 0; + + spin_lock_init(&ei->lock); + ei->outstanding_extents = 0; + if (sb->s_magic != BTRFS_TEST_MAGIC) + btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv, + BTRFS_BLOCK_RSV_DELALLOC); + ei->runtime_flags = 0; + ei->prop_compress = BTRFS_COMPRESS_NONE; + ei->defrag_compress = BTRFS_COMPRESS_NONE; + + ei->delayed_node = NULL; + + ei->i_otime.tv_sec = 0; + ei->i_otime.tv_nsec = 0; + + inode = &ei->vfs_inode; + extent_map_tree_init(&ei->extent_tree); + extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO, inode); + extent_io_tree_init(fs_info, &ei->io_failure_tree, + IO_TREE_INODE_IO_FAILURE, inode); + extent_io_tree_init(fs_info, &ei->file_extent_tree, + IO_TREE_INODE_FILE_EXTENT, inode); + ei->io_tree.track_uptodate = true; + ei->io_failure_tree.track_uptodate = true; + atomic_set(&ei->sync_writers, 0); + mutex_init(&ei->log_mutex); + btrfs_ordered_inode_tree_init(&ei->ordered_tree); + INIT_LIST_HEAD(&ei->delalloc_inodes); + INIT_LIST_HEAD(&ei->delayed_iput); + RB_CLEAR_NODE(&ei->rb_node); + init_rwsem(&ei->dio_sem); + + return inode; +} + +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS +void btrfs_test_destroy_inode(struct inode *inode) +{ + btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0); + kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); +} +#endif + +void btrfs_free_inode(struct inode *inode) +{ + kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode)); +} + +void btrfs_destroy_inode(struct inode *vfs_inode) +{ + struct btrfs_ordered_extent *ordered; + struct btrfs_inode *inode = BTRFS_I(vfs_inode); + struct btrfs_root *root = inode->root; + + WARN_ON(!hlist_empty(&vfs_inode->i_dentry)); + WARN_ON(vfs_inode->i_data.nrpages); + WARN_ON(inode->block_rsv.reserved); + WARN_ON(inode->block_rsv.size); + WARN_ON(inode->outstanding_extents); + WARN_ON(inode->delalloc_bytes); + WARN_ON(inode->new_delalloc_bytes); + WARN_ON(inode->csum_bytes); + WARN_ON(inode->defrag_bytes); + + /* + * This can happen where we create an inode, but somebody else also + * created the same inode and we need to destroy the one we already + * created. + */ + if (!root) + return; + + while (1) { + ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1); + if (!ordered) + break; + else { + btrfs_err(root->fs_info, + "found ordered extent %llu %llu on inode cleanup", + ordered->file_offset, ordered->num_bytes); + btrfs_remove_ordered_extent(inode, ordered); + btrfs_put_ordered_extent(ordered); + btrfs_put_ordered_extent(ordered); + } + } + btrfs_qgroup_check_reserved_leak(inode); + inode_tree_del(inode); + btrfs_drop_extent_cache(inode, 0, (u64)-1, 0); + btrfs_inode_clear_file_extent_range(inode, 0, (u64)-1); + btrfs_put_root(inode->root); +} + +int btrfs_drop_inode(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + + if (root == NULL) + return 1; + + /* the snap/subvol tree is on deleting */ + if (btrfs_root_refs(&root->root_item) == 0) + return 1; + else + return generic_drop_inode(inode); +} + +static void init_once(void *foo) +{ + struct btrfs_inode *ei = (struct btrfs_inode *) foo; + + inode_init_once(&ei->vfs_inode); +} + +void __cold btrfs_destroy_cachep(void) +{ + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + kmem_cache_destroy(btrfs_inode_cachep); + kmem_cache_destroy(btrfs_trans_handle_cachep); + kmem_cache_destroy(btrfs_path_cachep); + kmem_cache_destroy(btrfs_free_space_cachep); + kmem_cache_destroy(btrfs_free_space_bitmap_cachep); +} + +int __init btrfs_init_cachep(void) +{ + btrfs_inode_cachep = kmem_cache_create("btrfs_inode", + sizeof(struct btrfs_inode), 0, + SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT, + init_once); + if (!btrfs_inode_cachep) + goto fail; + + btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle", + sizeof(struct btrfs_trans_handle), 0, + SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL); + if (!btrfs_trans_handle_cachep) + goto fail; + + btrfs_path_cachep = kmem_cache_create("btrfs_path", + sizeof(struct btrfs_path), 0, + SLAB_MEM_SPREAD, NULL); + if (!btrfs_path_cachep) + goto fail; + + btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space", + sizeof(struct btrfs_free_space), 0, + SLAB_MEM_SPREAD, NULL); + if (!btrfs_free_space_cachep) + goto fail; + + btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap", + PAGE_SIZE, PAGE_SIZE, + SLAB_MEM_SPREAD, NULL); + if (!btrfs_free_space_bitmap_cachep) + goto fail; + + return 0; +fail: + btrfs_destroy_cachep(); + return -ENOMEM; +} + +static int btrfs_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int flags) +{ + u64 delalloc_bytes; + struct inode *inode = d_inode(path->dentry); + u32 blocksize = inode->i_sb->s_blocksize; + u32 bi_flags = BTRFS_I(inode)->flags; + + stat->result_mask |= STATX_BTIME; + stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec; + stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec; + if (bi_flags & BTRFS_INODE_APPEND) + stat->attributes |= STATX_ATTR_APPEND; + if (bi_flags & BTRFS_INODE_COMPRESS) + stat->attributes |= STATX_ATTR_COMPRESSED; + if (bi_flags & BTRFS_INODE_IMMUTABLE) + stat->attributes |= STATX_ATTR_IMMUTABLE; + if (bi_flags & BTRFS_INODE_NODUMP) + stat->attributes |= STATX_ATTR_NODUMP; + + stat->attributes_mask |= (STATX_ATTR_APPEND | + STATX_ATTR_COMPRESSED | + STATX_ATTR_IMMUTABLE | + STATX_ATTR_NODUMP); + + generic_fillattr(inode, stat); + stat->dev = BTRFS_I(inode)->root->anon_dev; + + spin_lock(&BTRFS_I(inode)->lock); + delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes; + spin_unlock(&BTRFS_I(inode)->lock); + stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) + + ALIGN(delalloc_bytes, blocksize)) >> 9; + return 0; +} + +static int btrfs_rename_exchange(struct inode *old_dir, + struct dentry *old_dentry, + struct inode *new_dir, + struct dentry *new_dentry) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(old_dir)->root; + struct btrfs_root *dest = BTRFS_I(new_dir)->root; + struct inode *new_inode = new_dentry->d_inode; + struct inode *old_inode = old_dentry->d_inode; + struct timespec64 ctime = current_time(old_inode); + u64 old_ino = btrfs_ino(BTRFS_I(old_inode)); + u64 new_ino = btrfs_ino(BTRFS_I(new_inode)); + u64 old_idx = 0; + u64 new_idx = 0; + int ret; + int ret2; + bool root_log_pinned = false; + bool dest_log_pinned = false; + bool need_abort = false; + + /* + * For non-subvolumes allow exchange only within one subvolume, in the + * same inode namespace. Two subvolumes (represented as directory) can + * be exchanged as they're a logical link and have a fixed inode number. + */ + if (root != dest && + (old_ino != BTRFS_FIRST_FREE_OBJECTID || + new_ino != BTRFS_FIRST_FREE_OBJECTID)) + return -EXDEV; + + /* close the race window with snapshot create/destroy ioctl */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID || + new_ino == BTRFS_FIRST_FREE_OBJECTID) + down_read(&fs_info->subvol_sem); + + /* + * We want to reserve the absolute worst case amount of items. So if + * both inodes are subvols and we need to unlink them then that would + * require 4 item modifications, but if they are both normal inodes it + * would require 5 item modifications, so we'll assume their normal + * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items + * should cover the worst case number of items we'll modify. + */ + trans = btrfs_start_transaction(root, 12); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_notrans; + } + + if (dest != root) + btrfs_record_root_in_trans(trans, dest); + + /* + * We need to find a free sequence number both in the source and + * in the destination directory for the exchange. + */ + ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx); + if (ret) + goto out_fail; + ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx); + if (ret) + goto out_fail; + + BTRFS_I(old_inode)->dir_index = 0ULL; + BTRFS_I(new_inode)->dir_index = 0ULL; + + /* Reference for the source. */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) { + /* force full log commit if subvolume involved. */ + btrfs_set_log_full_commit(trans); + } else { + btrfs_pin_log_trans(root); + root_log_pinned = true; + ret = btrfs_insert_inode_ref(trans, dest, + new_dentry->d_name.name, + new_dentry->d_name.len, + old_ino, + btrfs_ino(BTRFS_I(new_dir)), + old_idx); + if (ret) + goto out_fail; + need_abort = true; + } + + /* And now for the dest. */ + if (new_ino == BTRFS_FIRST_FREE_OBJECTID) { + /* force full log commit if subvolume involved. */ + btrfs_set_log_full_commit(trans); + } else { + btrfs_pin_log_trans(dest); + dest_log_pinned = true; + ret = btrfs_insert_inode_ref(trans, root, + old_dentry->d_name.name, + old_dentry->d_name.len, + new_ino, + btrfs_ino(BTRFS_I(old_dir)), + new_idx); + if (ret) { + if (need_abort) + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + } + + /* Update inode version and ctime/mtime. */ + inode_inc_iversion(old_dir); + inode_inc_iversion(new_dir); + inode_inc_iversion(old_inode); + inode_inc_iversion(new_inode); + old_dir->i_ctime = old_dir->i_mtime = ctime; + new_dir->i_ctime = new_dir->i_mtime = ctime; + old_inode->i_ctime = ctime; + new_inode->i_ctime = ctime; + + if (old_dentry->d_parent != new_dentry->d_parent) { + btrfs_record_unlink_dir(trans, BTRFS_I(old_dir), + BTRFS_I(old_inode), 1); + btrfs_record_unlink_dir(trans, BTRFS_I(new_dir), + BTRFS_I(new_inode), 1); + } + + /* src is a subvolume */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) { + ret = btrfs_unlink_subvol(trans, old_dir, old_dentry); + } else { /* src is an inode */ + ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir), + BTRFS_I(old_dentry->d_inode), + old_dentry->d_name.name, + old_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, root, old_inode); + } + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + + /* dest is a subvolume */ + if (new_ino == BTRFS_FIRST_FREE_OBJECTID) { + ret = btrfs_unlink_subvol(trans, new_dir, new_dentry); + } else { /* dest is an inode */ + ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir), + BTRFS_I(new_dentry->d_inode), + new_dentry->d_name.name, + new_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, dest, new_inode); + } + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + + ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode), + new_dentry->d_name.name, + new_dentry->d_name.len, 0, old_idx); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + + ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode), + old_dentry->d_name.name, + old_dentry->d_name.len, 0, new_idx); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + + if (old_inode->i_nlink == 1) + BTRFS_I(old_inode)->dir_index = old_idx; + if (new_inode->i_nlink == 1) + BTRFS_I(new_inode)->dir_index = new_idx; + + if (root_log_pinned) { + btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir), + new_dentry->d_parent); + btrfs_end_log_trans(root); + root_log_pinned = false; + } + if (dest_log_pinned) { + btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir), + old_dentry->d_parent); + btrfs_end_log_trans(dest); + dest_log_pinned = false; + } +out_fail: + /* + * If we have pinned a log and an error happened, we unpin tasks + * trying to sync the log and force them to fallback to a transaction + * commit if the log currently contains any of the inodes involved in + * this rename operation (to ensure we do not persist a log with an + * inconsistent state for any of these inodes or leading to any + * inconsistencies when replayed). If the transaction was aborted, the + * abortion reason is propagated to userspace when attempting to commit + * the transaction. If the log does not contain any of these inodes, we + * allow the tasks to sync it. + */ + if (ret && (root_log_pinned || dest_log_pinned)) { + if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) || + btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) || + btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) || + (new_inode && + btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))) + btrfs_set_log_full_commit(trans); + + if (root_log_pinned) { + btrfs_end_log_trans(root); + root_log_pinned = false; + } + if (dest_log_pinned) { + btrfs_end_log_trans(dest); + dest_log_pinned = false; + } + } + ret2 = btrfs_end_transaction(trans); + ret = ret ? ret : ret2; +out_notrans: + if (new_ino == BTRFS_FIRST_FREE_OBJECTID || + old_ino == BTRFS_FIRST_FREE_OBJECTID) + up_read(&fs_info->subvol_sem); + + return ret; +} + +static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct inode *dir, + struct dentry *dentry) +{ + int ret; + struct inode *inode; + u64 objectid; + u64 index; + + ret = btrfs_find_free_objectid(root, &objectid); + if (ret) + return ret; + + inode = btrfs_new_inode(trans, root, dir, + dentry->d_name.name, + dentry->d_name.len, + btrfs_ino(BTRFS_I(dir)), + objectid, + S_IFCHR | WHITEOUT_MODE, + &index); + + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + return ret; + } + + inode->i_op = &btrfs_special_inode_operations; + init_special_inode(inode, inode->i_mode, + WHITEOUT_DEV); + + ret = btrfs_init_inode_security(trans, inode, dir, + &dentry->d_name); + if (ret) + goto out; + + ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, + BTRFS_I(inode), 0, index); + if (ret) + goto out; + + ret = btrfs_update_inode(trans, root, inode); +out: + unlock_new_inode(inode); + if (ret) + inode_dec_link_count(inode); + iput(inode); + + return ret; +} + +static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb); + struct btrfs_trans_handle *trans; + unsigned int trans_num_items; + struct btrfs_root *root = BTRFS_I(old_dir)->root; + struct btrfs_root *dest = BTRFS_I(new_dir)->root; + struct inode *new_inode = d_inode(new_dentry); + struct inode *old_inode = d_inode(old_dentry); + u64 index = 0; + int ret; + int ret2; + u64 old_ino = btrfs_ino(BTRFS_I(old_inode)); + bool log_pinned = false; + + if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) + return -EPERM; + + /* we only allow rename subvolume link between subvolumes */ + if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest) + return -EXDEV; + + if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID || + (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID)) + return -ENOTEMPTY; + + if (S_ISDIR(old_inode->i_mode) && new_inode && + new_inode->i_size > BTRFS_EMPTY_DIR_SIZE) + return -ENOTEMPTY; + + + /* check for collisions, even if the name isn't there */ + ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino, + new_dentry->d_name.name, + new_dentry->d_name.len); + + if (ret) { + if (ret == -EEXIST) { + /* we shouldn't get + * eexist without a new_inode */ + if (WARN_ON(!new_inode)) { + return ret; + } + } else { + /* maybe -EOVERFLOW */ + return ret; + } + } + ret = 0; + + /* + * we're using rename to replace one file with another. Start IO on it + * now so we don't add too much work to the end of the transaction + */ + if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size) + filemap_flush(old_inode->i_mapping); + + /* close the racy window with snapshot create/destroy ioctl */ + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + down_read(&fs_info->subvol_sem); + /* + * We want to reserve the absolute worst case amount of items. So if + * both inodes are subvols and we need to unlink them then that would + * require 4 item modifications, but if they are both normal inodes it + * would require 5 item modifications, so we'll assume they are normal + * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items + * should cover the worst case number of items we'll modify. + * If our rename has the whiteout flag, we need more 5 units for the + * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item + * when selinux is enabled). + */ + trans_num_items = 11; + if (flags & RENAME_WHITEOUT) + trans_num_items += 5; + trans = btrfs_start_transaction(root, trans_num_items); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_notrans; + } + + if (dest != root) + btrfs_record_root_in_trans(trans, dest); + + ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index); + if (ret) + goto out_fail; + + BTRFS_I(old_inode)->dir_index = 0ULL; + if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { + /* force full log commit if subvolume involved. */ + btrfs_set_log_full_commit(trans); + } else { + btrfs_pin_log_trans(root); + log_pinned = true; + ret = btrfs_insert_inode_ref(trans, dest, + new_dentry->d_name.name, + new_dentry->d_name.len, + old_ino, + btrfs_ino(BTRFS_I(new_dir)), index); + if (ret) + goto out_fail; + } + + inode_inc_iversion(old_dir); + inode_inc_iversion(new_dir); + inode_inc_iversion(old_inode); + old_dir->i_ctime = old_dir->i_mtime = + new_dir->i_ctime = new_dir->i_mtime = + old_inode->i_ctime = current_time(old_dir); + + if (old_dentry->d_parent != new_dentry->d_parent) + btrfs_record_unlink_dir(trans, BTRFS_I(old_dir), + BTRFS_I(old_inode), 1); + + if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) { + ret = btrfs_unlink_subvol(trans, old_dir, old_dentry); + } else { + ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir), + BTRFS_I(d_inode(old_dentry)), + old_dentry->d_name.name, + old_dentry->d_name.len); + if (!ret) + ret = btrfs_update_inode(trans, root, old_inode); + } + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + + if (new_inode) { + inode_inc_iversion(new_inode); + new_inode->i_ctime = current_time(new_inode); + if (unlikely(btrfs_ino(BTRFS_I(new_inode)) == + BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) { + ret = btrfs_unlink_subvol(trans, new_dir, new_dentry); + BUG_ON(new_inode->i_nlink == 0); + } else { + ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir), + BTRFS_I(d_inode(new_dentry)), + new_dentry->d_name.name, + new_dentry->d_name.len); + } + if (!ret && new_inode->i_nlink == 0) + ret = btrfs_orphan_add(trans, + BTRFS_I(d_inode(new_dentry))); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + } + + ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode), + new_dentry->d_name.name, + new_dentry->d_name.len, 0, index); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + + if (old_inode->i_nlink == 1) + BTRFS_I(old_inode)->dir_index = index; + + if (log_pinned) { + btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir), + new_dentry->d_parent); + btrfs_end_log_trans(root); + log_pinned = false; + } + + if (flags & RENAME_WHITEOUT) { + ret = btrfs_whiteout_for_rename(trans, root, old_dir, + old_dentry); + + if (ret) { + btrfs_abort_transaction(trans, ret); + goto out_fail; + } + } +out_fail: + /* + * If we have pinned the log and an error happened, we unpin tasks + * trying to sync the log and force them to fallback to a transaction + * commit if the log currently contains any of the inodes involved in + * this rename operation (to ensure we do not persist a log with an + * inconsistent state for any of these inodes or leading to any + * inconsistencies when replayed). If the transaction was aborted, the + * abortion reason is propagated to userspace when attempting to commit + * the transaction. If the log does not contain any of these inodes, we + * allow the tasks to sync it. + */ + if (ret && log_pinned) { + if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) || + btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) || + btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) || + (new_inode && + btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation))) + btrfs_set_log_full_commit(trans); + + btrfs_end_log_trans(root); + log_pinned = false; + } + ret2 = btrfs_end_transaction(trans); + ret = ret ? ret : ret2; +out_notrans: + if (old_ino == BTRFS_FIRST_FREE_OBJECTID) + up_read(&fs_info->subvol_sem); + + return ret; +} + +static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT)) + return -EINVAL; + + if (flags & RENAME_EXCHANGE) + return btrfs_rename_exchange(old_dir, old_dentry, new_dir, + new_dentry); + + return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags); +} + +struct btrfs_delalloc_work { + struct inode *inode; + struct completion completion; + struct list_head list; + struct btrfs_work work; +}; + +static void btrfs_run_delalloc_work(struct btrfs_work *work) +{ + struct btrfs_delalloc_work *delalloc_work; + struct inode *inode; + + delalloc_work = container_of(work, struct btrfs_delalloc_work, + work); + inode = delalloc_work->inode; + filemap_flush(inode->i_mapping); + if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) + filemap_flush(inode->i_mapping); + + iput(inode); + complete(&delalloc_work->completion); +} + +static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode) +{ + struct btrfs_delalloc_work *work; + + work = kmalloc(sizeof(*work), GFP_NOFS); + if (!work) + return NULL; + + init_completion(&work->completion); + INIT_LIST_HEAD(&work->list); + work->inode = inode; + btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL); + + return work; +} + +/* + * some fairly slow code that needs optimization. This walks the list + * of all the inodes with pending delalloc and forces them to disk. + */ +static int start_delalloc_inodes(struct btrfs_root *root, + struct writeback_control *wbc, bool snapshot, + bool in_reclaim_context) +{ + struct btrfs_inode *binode; + struct inode *inode; + struct btrfs_delalloc_work *work, *next; + struct list_head works; + struct list_head splice; + int ret = 0; + bool full_flush = wbc->nr_to_write == LONG_MAX; + + INIT_LIST_HEAD(&works); + INIT_LIST_HEAD(&splice); + + mutex_lock(&root->delalloc_mutex); + spin_lock(&root->delalloc_lock); + list_splice_init(&root->delalloc_inodes, &splice); + while (!list_empty(&splice)) { + binode = list_entry(splice.next, struct btrfs_inode, + delalloc_inodes); + + list_move_tail(&binode->delalloc_inodes, + &root->delalloc_inodes); + + if (in_reclaim_context && + test_bit(BTRFS_INODE_NO_DELALLOC_FLUSH, &binode->runtime_flags)) + continue; + + inode = igrab(&binode->vfs_inode); + if (!inode) { + cond_resched_lock(&root->delalloc_lock); + continue; + } + spin_unlock(&root->delalloc_lock); + + if (snapshot) + set_bit(BTRFS_INODE_SNAPSHOT_FLUSH, + &binode->runtime_flags); + if (full_flush) { + work = btrfs_alloc_delalloc_work(inode); + if (!work) { + iput(inode); + ret = -ENOMEM; + goto out; + } + list_add_tail(&work->list, &works); + btrfs_queue_work(root->fs_info->flush_workers, + &work->work); + } else { + ret = sync_inode(inode, wbc); + if (!ret && + test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, + &BTRFS_I(inode)->runtime_flags)) + ret = sync_inode(inode, wbc); + btrfs_add_delayed_iput(inode); + if (ret || wbc->nr_to_write <= 0) + goto out; + } + cond_resched(); + spin_lock(&root->delalloc_lock); + } + spin_unlock(&root->delalloc_lock); + +out: + list_for_each_entry_safe(work, next, &works, list) { + list_del_init(&work->list); + wait_for_completion(&work->completion); + kfree(work); + } + + if (!list_empty(&splice)) { + spin_lock(&root->delalloc_lock); + list_splice_tail(&splice, &root->delalloc_inodes); + spin_unlock(&root->delalloc_lock); + } + mutex_unlock(&root->delalloc_mutex); + return ret; +} + +int btrfs_start_delalloc_snapshot(struct btrfs_root *root) +{ + struct writeback_control wbc = { + .nr_to_write = LONG_MAX, + .sync_mode = WB_SYNC_NONE, + .range_start = 0, + .range_end = LLONG_MAX, + }; + struct btrfs_fs_info *fs_info = root->fs_info; + + if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) + return -EROFS; + + return start_delalloc_inodes(root, &wbc, true, false); +} + +int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, u64 nr, + bool in_reclaim_context) +{ + struct writeback_control wbc = { + .nr_to_write = (nr == U64_MAX) ? LONG_MAX : (unsigned long)nr, + .sync_mode = WB_SYNC_NONE, + .range_start = 0, + .range_end = LLONG_MAX, + }; + struct btrfs_root *root; + struct list_head splice; + int ret; + + if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) + return -EROFS; + + INIT_LIST_HEAD(&splice); + + mutex_lock(&fs_info->delalloc_root_mutex); + spin_lock(&fs_info->delalloc_root_lock); + list_splice_init(&fs_info->delalloc_roots, &splice); + while (!list_empty(&splice) && nr) { + /* + * Reset nr_to_write here so we know that we're doing a full + * flush. + */ + if (nr == U64_MAX) + wbc.nr_to_write = LONG_MAX; + + root = list_first_entry(&splice, struct btrfs_root, + delalloc_root); + root = btrfs_grab_root(root); + BUG_ON(!root); + list_move_tail(&root->delalloc_root, + &fs_info->delalloc_roots); + spin_unlock(&fs_info->delalloc_root_lock); + + ret = start_delalloc_inodes(root, &wbc, false, in_reclaim_context); + btrfs_put_root(root); + if (ret < 0 || wbc.nr_to_write <= 0) + goto out; + spin_lock(&fs_info->delalloc_root_lock); + } + spin_unlock(&fs_info->delalloc_root_lock); + + ret = 0; +out: + if (!list_empty(&splice)) { + spin_lock(&fs_info->delalloc_root_lock); + list_splice_tail(&splice, &fs_info->delalloc_roots); + spin_unlock(&fs_info->delalloc_root_lock); + } + mutex_unlock(&fs_info->delalloc_root_mutex); + return ret; +} + +static int btrfs_symlink(struct inode *dir, struct dentry *dentry, + const char *symname) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct btrfs_path *path; + struct btrfs_key key; + struct inode *inode = NULL; + int err; + u64 objectid; + u64 index = 0; + int name_len; + int datasize; + unsigned long ptr; + struct btrfs_file_extent_item *ei; + struct extent_buffer *leaf; + + name_len = strlen(symname); + if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info)) + return -ENAMETOOLONG; + + /* + * 2 items for inode item and ref + * 2 items for dir items + * 1 item for updating parent inode item + * 1 item for the inline extent item + * 1 item for xattr if selinux is on + */ + trans = btrfs_start_transaction(root, 7); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + err = btrfs_find_free_objectid(root, &objectid); + if (err) + goto out_unlock; + + inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name, + dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), + objectid, S_IFLNK|S_IRWXUGO, &index); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + inode = NULL; + goto out_unlock; + } + + /* + * If the active LSM wants to access the inode during + * d_instantiate it needs these. Smack checks to see + * if the filesystem supports xattrs by looking at the + * ops vector. + */ + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + inode->i_mapping->a_ops = &btrfs_aops; + + err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name); + if (err) + goto out_unlock; + + path = btrfs_alloc_path(); + if (!path) { + err = -ENOMEM; + goto out_unlock; + } + key.objectid = btrfs_ino(BTRFS_I(inode)); + key.offset = 0; + key.type = BTRFS_EXTENT_DATA_KEY; + datasize = btrfs_file_extent_calc_inline_size(name_len); + err = btrfs_insert_empty_item(trans, root, path, &key, + datasize); + if (err) { + btrfs_free_path(path); + goto out_unlock; + } + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_file_extent_item); + btrfs_set_file_extent_generation(leaf, ei, trans->transid); + btrfs_set_file_extent_type(leaf, ei, + BTRFS_FILE_EXTENT_INLINE); + btrfs_set_file_extent_encryption(leaf, ei, 0); + btrfs_set_file_extent_compression(leaf, ei, 0); + btrfs_set_file_extent_other_encoding(leaf, ei, 0); + btrfs_set_file_extent_ram_bytes(leaf, ei, name_len); + + ptr = btrfs_file_extent_inline_start(ei); + write_extent_buffer(leaf, symname, ptr, name_len); + btrfs_mark_buffer_dirty(leaf); + btrfs_free_path(path); + + inode->i_op = &btrfs_symlink_inode_operations; + inode_nohighmem(inode); + inode_set_bytes(inode, name_len); + btrfs_i_size_write(BTRFS_I(inode), name_len); + err = btrfs_update_inode(trans, root, inode); + /* + * Last step, add directory indexes for our symlink inode. This is the + * last step to avoid extra cleanup of these indexes if an error happens + * elsewhere above. + */ + if (!err) + err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, + BTRFS_I(inode), 0, index); + if (err) + goto out_unlock; + + d_instantiate_new(dentry, inode); + +out_unlock: + btrfs_end_transaction(trans); + if (err && inode) { + inode_dec_link_count(inode); + discard_new_inode(inode); + } + btrfs_btree_balance_dirty(fs_info); + return err; +} + +static struct btrfs_trans_handle *insert_prealloc_file_extent( + struct btrfs_trans_handle *trans_in, + struct inode *inode, struct btrfs_key *ins, + u64 file_offset) +{ + struct btrfs_file_extent_item stack_fi; + struct btrfs_replace_extent_info extent_info; + struct btrfs_trans_handle *trans = trans_in; + struct btrfs_path *path; + u64 start = ins->objectid; + u64 len = ins->offset; + int ret; + + memset(&stack_fi, 0, sizeof(stack_fi)); + + btrfs_set_stack_file_extent_type(&stack_fi, BTRFS_FILE_EXTENT_PREALLOC); + btrfs_set_stack_file_extent_disk_bytenr(&stack_fi, start); + btrfs_set_stack_file_extent_disk_num_bytes(&stack_fi, len); + btrfs_set_stack_file_extent_num_bytes(&stack_fi, len); + btrfs_set_stack_file_extent_ram_bytes(&stack_fi, len); + btrfs_set_stack_file_extent_compression(&stack_fi, BTRFS_COMPRESS_NONE); + /* Encryption and other encoding is reserved and all 0 */ + + ret = btrfs_qgroup_release_data(BTRFS_I(inode), file_offset, len); + if (ret < 0) + return ERR_PTR(ret); + + if (trans) { + ret = insert_reserved_file_extent(trans, BTRFS_I(inode), + file_offset, &stack_fi, ret); + if (ret) + return ERR_PTR(ret); + return trans; + } + + extent_info.disk_offset = start; + extent_info.disk_len = len; + extent_info.data_offset = 0; + extent_info.data_len = len; + extent_info.file_offset = file_offset; + extent_info.extent_buf = (char *)&stack_fi; + extent_info.is_new_extent = true; + extent_info.qgroup_reserved = ret; + extent_info.insertions = 0; + + path = btrfs_alloc_path(); + if (!path) + return ERR_PTR(-ENOMEM); + + ret = btrfs_replace_file_extents(inode, path, file_offset, + file_offset + len - 1, &extent_info, + &trans); + btrfs_free_path(path); + if (ret) + return ERR_PTR(ret); + + return trans; +} + +static int __btrfs_prealloc_file_range(struct inode *inode, int mode, + u64 start, u64 num_bytes, u64 min_size, + loff_t actual_len, u64 *alloc_hint, + struct btrfs_trans_handle *trans) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct extent_map *em; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_key ins; + u64 cur_offset = start; + u64 clear_offset = start; + u64 i_size; + u64 cur_bytes; + u64 last_alloc = (u64)-1; + int ret = 0; + bool own_trans = true; + u64 end = start + num_bytes - 1; + + if (trans) + own_trans = false; + while (num_bytes > 0) { + cur_bytes = min_t(u64, num_bytes, SZ_256M); + cur_bytes = max(cur_bytes, min_size); + /* + * If we are severely fragmented we could end up with really + * small allocations, so if the allocator is returning small + * chunks lets make its job easier by only searching for those + * sized chunks. + */ + cur_bytes = min(cur_bytes, last_alloc); + ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes, + min_size, 0, *alloc_hint, &ins, 1, 0); + if (ret) + break; + + /* + * We've reserved this space, and thus converted it from + * ->bytes_may_use to ->bytes_reserved. Any error that happens + * from here on out we will only need to clear our reservation + * for the remaining unreserved area, so advance our + * clear_offset by our extent size. + */ + clear_offset += ins.offset; + + last_alloc = ins.offset; + trans = insert_prealloc_file_extent(trans, inode, &ins, cur_offset); + /* + * Now that we inserted the prealloc extent we can finally + * decrement the number of reservations in the block group. + * If we did it before, we could race with relocation and have + * relocation miss the reserved extent, making it fail later. + */ + btrfs_dec_block_group_reservations(fs_info, ins.objectid); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + btrfs_free_reserved_extent(fs_info, ins.objectid, + ins.offset, 0); + break; + } + + btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset, + cur_offset + ins.offset -1, 0); + + em = alloc_extent_map(); + if (!em) { + set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, + &BTRFS_I(inode)->runtime_flags); + goto next; + } + + em->start = cur_offset; + em->orig_start = cur_offset; + em->len = ins.offset; + em->block_start = ins.objectid; + em->block_len = ins.offset; + em->orig_block_len = ins.offset; + em->ram_bytes = ins.offset; + set_bit(EXTENT_FLAG_PREALLOC, &em->flags); + em->generation = trans->transid; + + while (1) { + write_lock(&em_tree->lock); + ret = add_extent_mapping(em_tree, em, 1); + write_unlock(&em_tree->lock); + if (ret != -EEXIST) + break; + btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset, + cur_offset + ins.offset - 1, + 0); + } + free_extent_map(em); +next: + num_bytes -= ins.offset; + cur_offset += ins.offset; + *alloc_hint = ins.objectid + ins.offset; + + inode_inc_iversion(inode); + inode->i_ctime = current_time(inode); + BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC; + if (!(mode & FALLOC_FL_KEEP_SIZE) && + (actual_len > inode->i_size) && + (cur_offset > inode->i_size)) { + if (cur_offset > actual_len) + i_size = actual_len; + else + i_size = cur_offset; + i_size_write(inode, i_size); + btrfs_inode_safe_disk_i_size_write(inode, 0); + } + + ret = btrfs_update_inode(trans, root, inode); + + if (ret) { + btrfs_abort_transaction(trans, ret); + if (own_trans) + btrfs_end_transaction(trans); + break; + } + + if (own_trans) { + btrfs_end_transaction(trans); + trans = NULL; + } + } + if (clear_offset < end) + btrfs_free_reserved_data_space(BTRFS_I(inode), NULL, clear_offset, + end - clear_offset + 1); + return ret; +} + +int btrfs_prealloc_file_range(struct inode *inode, int mode, + u64 start, u64 num_bytes, u64 min_size, + loff_t actual_len, u64 *alloc_hint) +{ + return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, + min_size, actual_len, alloc_hint, + NULL); +} + +int btrfs_prealloc_file_range_trans(struct inode *inode, + struct btrfs_trans_handle *trans, int mode, + u64 start, u64 num_bytes, u64 min_size, + loff_t actual_len, u64 *alloc_hint) +{ + return __btrfs_prealloc_file_range(inode, mode, start, num_bytes, + min_size, actual_len, alloc_hint, trans); +} + +static int btrfs_set_page_dirty(struct page *page) +{ + return __set_page_dirty_nobuffers(page); +} + +static int btrfs_permission(struct inode *inode, int mask) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + umode_t mode = inode->i_mode; + + if (mask & MAY_WRITE && + (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) { + if (btrfs_root_readonly(root)) + return -EROFS; + if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) + return -EACCES; + } + return generic_permission(inode, mask); +} + +static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb); + struct btrfs_trans_handle *trans; + struct btrfs_root *root = BTRFS_I(dir)->root; + struct inode *inode = NULL; + u64 objectid; + u64 index; + int ret = 0; + + /* + * 5 units required for adding orphan entry + */ + trans = btrfs_start_transaction(root, 5); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_find_free_objectid(root, &objectid); + if (ret) + goto out; + + inode = btrfs_new_inode(trans, root, dir, NULL, 0, + btrfs_ino(BTRFS_I(dir)), objectid, mode, &index); + if (IS_ERR(inode)) { + ret = PTR_ERR(inode); + inode = NULL; + goto out; + } + + inode->i_fop = &btrfs_file_operations; + inode->i_op = &btrfs_file_inode_operations; + + inode->i_mapping->a_ops = &btrfs_aops; + + ret = btrfs_init_inode_security(trans, inode, dir, NULL); + if (ret) + goto out; + + ret = btrfs_update_inode(trans, root, inode); + if (ret) + goto out; + ret = btrfs_orphan_add(trans, BTRFS_I(inode)); + if (ret) + goto out; + + /* + * We set number of links to 0 in btrfs_new_inode(), and here we set + * it to 1 because d_tmpfile() will issue a warning if the count is 0, + * through: + * + * d_tmpfile() -> inode_dec_link_count() -> drop_nlink() + */ + set_nlink(inode, 1); + d_tmpfile(dentry, inode); + unlock_new_inode(inode); + mark_inode_dirty(inode); +out: + btrfs_end_transaction(trans); + if (ret && inode) + discard_new_inode(inode); + btrfs_btree_balance_dirty(fs_info); + return ret; +} + +void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end) +{ + struct inode *inode = tree->private_data; + unsigned long index = start >> PAGE_SHIFT; + unsigned long end_index = end >> PAGE_SHIFT; + struct page *page; + + while (index <= end_index) { + page = find_get_page(inode->i_mapping, index); + ASSERT(page); /* Pages should be in the extent_io_tree */ + set_page_writeback(page); + put_page(page); + index++; + } +} + +#ifdef CONFIG_SWAP +/* + * Add an entry indicating a block group or device which is pinned by a + * swapfile. Returns 0 on success, 1 if there is already an entry for it, or a + * negative errno on failure. + */ +static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr, + bool is_block_group) +{ + struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; + struct btrfs_swapfile_pin *sp, *entry; + struct rb_node **p; + struct rb_node *parent = NULL; + + sp = kmalloc(sizeof(*sp), GFP_NOFS); + if (!sp) + return -ENOMEM; + sp->ptr = ptr; + sp->inode = inode; + sp->is_block_group = is_block_group; + sp->bg_extent_count = 1; + + spin_lock(&fs_info->swapfile_pins_lock); + p = &fs_info->swapfile_pins.rb_node; + while (*p) { + parent = *p; + entry = rb_entry(parent, struct btrfs_swapfile_pin, node); + if (sp->ptr < entry->ptr || + (sp->ptr == entry->ptr && sp->inode < entry->inode)) { + p = &(*p)->rb_left; + } else if (sp->ptr > entry->ptr || + (sp->ptr == entry->ptr && sp->inode > entry->inode)) { + p = &(*p)->rb_right; + } else { + if (is_block_group) + entry->bg_extent_count++; + spin_unlock(&fs_info->swapfile_pins_lock); + kfree(sp); + return 1; + } + } + rb_link_node(&sp->node, parent, p); + rb_insert_color(&sp->node, &fs_info->swapfile_pins); + spin_unlock(&fs_info->swapfile_pins_lock); + return 0; +} + +/* Free all of the entries pinned by this swapfile. */ +static void btrfs_free_swapfile_pins(struct inode *inode) +{ + struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; + struct btrfs_swapfile_pin *sp; + struct rb_node *node, *next; + + spin_lock(&fs_info->swapfile_pins_lock); + node = rb_first(&fs_info->swapfile_pins); + while (node) { + next = rb_next(node); + sp = rb_entry(node, struct btrfs_swapfile_pin, node); + if (sp->inode == inode) { + rb_erase(&sp->node, &fs_info->swapfile_pins); + if (sp->is_block_group) { + btrfs_dec_block_group_swap_extents(sp->ptr, + sp->bg_extent_count); + btrfs_put_block_group(sp->ptr); + } + kfree(sp); + } + node = next; + } + spin_unlock(&fs_info->swapfile_pins_lock); +} + +struct btrfs_swap_info { + u64 start; + u64 block_start; + u64 block_len; + u64 lowest_ppage; + u64 highest_ppage; + unsigned long nr_pages; + int nr_extents; +}; + +static int btrfs_add_swap_extent(struct swap_info_struct *sis, + struct btrfs_swap_info *bsi) +{ + unsigned long nr_pages; + unsigned long max_pages; + u64 first_ppage, first_ppage_reported, next_ppage; + int ret; + + /* + * Our swapfile may have had its size extended after the swap header was + * written. In that case activating the swapfile should not go beyond + * the max size set in the swap header. + */ + if (bsi->nr_pages >= sis->max) + return 0; + + max_pages = sis->max - bsi->nr_pages; + first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT; + next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len, + PAGE_SIZE) >> PAGE_SHIFT; + + if (first_ppage >= next_ppage) + return 0; + nr_pages = next_ppage - first_ppage; + nr_pages = min(nr_pages, max_pages); + + first_ppage_reported = first_ppage; + if (bsi->start == 0) + first_ppage_reported++; + if (bsi->lowest_ppage > first_ppage_reported) + bsi->lowest_ppage = first_ppage_reported; + if (bsi->highest_ppage < (next_ppage - 1)) + bsi->highest_ppage = next_ppage - 1; + + ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage); + if (ret < 0) + return ret; + bsi->nr_extents += ret; + bsi->nr_pages += nr_pages; + return 0; +} + +static void btrfs_swap_deactivate(struct file *file) +{ + struct inode *inode = file_inode(file); + + btrfs_free_swapfile_pins(inode); + atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles); +} + +static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, + sector_t *span) +{ + struct inode *inode = file_inode(file); + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; + struct extent_state *cached_state = NULL; + struct extent_map *em = NULL; + struct btrfs_device *device = NULL; + struct btrfs_swap_info bsi = { + .lowest_ppage = (sector_t)-1ULL, + }; + int ret = 0; + u64 isize; + u64 start; + + /* + * If the swap file was just created, make sure delalloc is done. If the + * file changes again after this, the user is doing something stupid and + * we don't really care. + */ + ret = btrfs_wait_ordered_range(inode, 0, (u64)-1); + if (ret) + return ret; + + /* + * The inode is locked, so these flags won't change after we check them. + */ + if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) { + btrfs_warn(fs_info, "swapfile must not be compressed"); + return -EINVAL; + } + if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) { + btrfs_warn(fs_info, "swapfile must not be copy-on-write"); + return -EINVAL; + } + if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) { + btrfs_warn(fs_info, "swapfile must not be checksummed"); + return -EINVAL; + } + + /* + * Balance or device remove/replace/resize can move stuff around from + * under us. The exclop protection makes sure they aren't running/won't + * run concurrently while we are mapping the swap extents, and + * fs_info->swapfile_pins prevents them from running while the swap + * file is active and moving the extents. Note that this also prevents + * a concurrent device add which isn't actually necessary, but it's not + * really worth the trouble to allow it. + */ + if (!btrfs_exclop_start(fs_info, BTRFS_EXCLOP_SWAP_ACTIVATE)) { + btrfs_warn(fs_info, + "cannot activate swapfile while exclusive operation is running"); + return -EBUSY; + } + + /* + * Prevent snapshot creation while we are activating the swap file. + * We do not want to race with snapshot creation. If snapshot creation + * already started before we bumped nr_swapfiles from 0 to 1 and + * completes before the first write into the swap file after it is + * activated, than that write would fallback to COW. + */ + if (!btrfs_drew_try_write_lock(&root->snapshot_lock)) { + btrfs_exclop_finish(fs_info); + btrfs_warn(fs_info, + "cannot activate swapfile because snapshot creation is in progress"); + return -EINVAL; + } + /* + * Snapshots can create extents which require COW even if NODATACOW is + * set. We use this counter to prevent snapshots. We must increment it + * before walking the extents because we don't want a concurrent + * snapshot to run after we've already checked the extents. + * + * It is possible that subvolume is marked for deletion but still not + * removed yet. To prevent this race, we check the root status before + * activating the swapfile. + */ + spin_lock(&root->root_item_lock); + if (btrfs_root_dead(root)) { + spin_unlock(&root->root_item_lock); + + btrfs_exclop_finish(fs_info); + btrfs_warn(fs_info, + "cannot activate swapfile because subvolume %llu is being deleted", + root->root_key.objectid); + return -EPERM; + } + atomic_inc(&root->nr_swapfiles); + spin_unlock(&root->root_item_lock); + + isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize); + + lock_extent_bits(io_tree, 0, isize - 1, &cached_state); + start = 0; + while (start < isize) { + u64 logical_block_start, physical_block_start; + struct btrfs_block_group *bg; + u64 len = isize - start; + + em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto out; + } + + if (em->block_start == EXTENT_MAP_HOLE) { + btrfs_warn(fs_info, "swapfile must not have holes"); + ret = -EINVAL; + goto out; + } + if (em->block_start == EXTENT_MAP_INLINE) { + /* + * It's unlikely we'll ever actually find ourselves + * here, as a file small enough to fit inline won't be + * big enough to store more than the swap header, but in + * case something changes in the future, let's catch it + * here rather than later. + */ + btrfs_warn(fs_info, "swapfile must not be inline"); + ret = -EINVAL; + goto out; + } + if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) { + btrfs_warn(fs_info, "swapfile must not be compressed"); + ret = -EINVAL; + goto out; + } + + logical_block_start = em->block_start + (start - em->start); + len = min(len, em->len - (start - em->start)); + free_extent_map(em); + em = NULL; + + ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL, true); + if (ret < 0) { + goto out; + } else if (ret) { + ret = 0; + } else { + btrfs_warn(fs_info, + "swapfile must not be copy-on-write"); + ret = -EINVAL; + goto out; + } + + em = btrfs_get_chunk_map(fs_info, logical_block_start, len); + if (IS_ERR(em)) { + ret = PTR_ERR(em); + goto out; + } + + if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) { + btrfs_warn(fs_info, + "swapfile must have single data profile"); + ret = -EINVAL; + goto out; + } + + if (device == NULL) { + device = em->map_lookup->stripes[0].dev; + ret = btrfs_add_swapfile_pin(inode, device, false); + if (ret == 1) + ret = 0; + else if (ret) + goto out; + } else if (device != em->map_lookup->stripes[0].dev) { + btrfs_warn(fs_info, "swapfile must be on one device"); + ret = -EINVAL; + goto out; + } + + physical_block_start = (em->map_lookup->stripes[0].physical + + (logical_block_start - em->start)); + len = min(len, em->len - (logical_block_start - em->start)); + free_extent_map(em); + em = NULL; + + bg = btrfs_lookup_block_group(fs_info, logical_block_start); + if (!bg) { + btrfs_warn(fs_info, + "could not find block group containing swapfile"); + ret = -EINVAL; + goto out; + } + + if (!btrfs_inc_block_group_swap_extents(bg)) { + btrfs_warn(fs_info, + "block group for swapfile at %llu is read-only%s", + bg->start, + atomic_read(&fs_info->scrubs_running) ? + " (scrub running)" : ""); + btrfs_put_block_group(bg); + ret = -EINVAL; + goto out; + } + + ret = btrfs_add_swapfile_pin(inode, bg, true); + if (ret) { + btrfs_put_block_group(bg); + if (ret == 1) + ret = 0; + else + goto out; + } + + if (bsi.block_len && + bsi.block_start + bsi.block_len == physical_block_start) { + bsi.block_len += len; + } else { + if (bsi.block_len) { + ret = btrfs_add_swap_extent(sis, &bsi); + if (ret) + goto out; + } + bsi.start = start; + bsi.block_start = physical_block_start; + bsi.block_len = len; + } + + start += len; + } + + if (bsi.block_len) + ret = btrfs_add_swap_extent(sis, &bsi); + +out: + if (!IS_ERR_OR_NULL(em)) + free_extent_map(em); + + unlock_extent_cached(io_tree, 0, isize - 1, &cached_state); + + if (ret) + btrfs_swap_deactivate(file); + + btrfs_drew_write_unlock(&root->snapshot_lock); + + btrfs_exclop_finish(fs_info); + + if (ret) + return ret; + + if (device) + sis->bdev = device->bdev; + *span = bsi.highest_ppage - bsi.lowest_ppage + 1; + sis->max = bsi.nr_pages; + sis->pages = bsi.nr_pages - 1; + sis->highest_bit = bsi.nr_pages - 1; + return bsi.nr_extents; +} +#else +static void btrfs_swap_deactivate(struct file *file) +{ +} + +static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, + sector_t *span) +{ + return -EOPNOTSUPP; +} +#endif + +static const struct inode_operations btrfs_dir_inode_operations = { + .getattr = btrfs_getattr, + .lookup = btrfs_lookup, + .create = btrfs_create, + .unlink = btrfs_unlink, + .link = btrfs_link, + .mkdir = btrfs_mkdir, + .rmdir = btrfs_rmdir, + .rename = btrfs_rename2, + .symlink = btrfs_symlink, + .setattr = btrfs_setattr, + .mknod = btrfs_mknod, + .listxattr = btrfs_listxattr, + .permission = btrfs_permission, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, + .tmpfile = btrfs_tmpfile, +}; + +static const struct file_operations btrfs_dir_file_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .iterate_shared = btrfs_real_readdir, + .open = btrfs_opendir, + .unlocked_ioctl = btrfs_ioctl, +#ifdef CONFIG_COMPAT + .compat_ioctl = btrfs_compat_ioctl, +#endif + .release = btrfs_release_file, + .fsync = btrfs_sync_file, +}; + +/* + * btrfs doesn't support the bmap operation because swapfiles + * use bmap to make a mapping of extents in the file. They assume + * these extents won't change over the life of the file and they + * use the bmap result to do IO directly to the drive. + * + * the btrfs bmap call would return logical addresses that aren't + * suitable for IO and they also will change frequently as COW + * operations happen. So, swapfile + btrfs == corruption. + * + * For now we're avoiding this by dropping bmap. + */ +static const struct address_space_operations btrfs_aops = { + .readpage = btrfs_readpage, + .writepage = btrfs_writepage, + .writepages = btrfs_writepages, + .readahead = btrfs_readahead, + .direct_IO = noop_direct_IO, + .invalidatepage = btrfs_invalidatepage, + .releasepage = btrfs_releasepage, +#ifdef CONFIG_MIGRATION + .migratepage = btrfs_migratepage, +#endif + .set_page_dirty = btrfs_set_page_dirty, + .error_remove_page = generic_error_remove_page, + .swap_activate = btrfs_swap_activate, + .swap_deactivate = btrfs_swap_deactivate, +}; + +static const struct inode_operations btrfs_file_inode_operations = { + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .listxattr = btrfs_listxattr, + .permission = btrfs_permission, + .fiemap = btrfs_fiemap, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, +}; +static const struct inode_operations btrfs_special_inode_operations = { + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .permission = btrfs_permission, + .listxattr = btrfs_listxattr, + .get_acl = btrfs_get_acl, + .set_acl = btrfs_set_acl, + .update_time = btrfs_update_time, +}; +static const struct inode_operations btrfs_symlink_inode_operations = { + .get_link = page_get_link, + .getattr = btrfs_getattr, + .setattr = btrfs_setattr, + .permission = btrfs_permission, + .listxattr = btrfs_listxattr, + .update_time = btrfs_update_time, +}; + +const struct dentry_operations btrfs_dentry_operations = { + .d_delete = btrfs_dentry_delete, +}; |