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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/btrfs/file-item.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/btrfs/file-item.c')
-rw-r--r--fs/btrfs/file-item.c1304
1 files changed, 1304 insertions, 0 deletions
diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
new file mode 100644
index 000000000..14478da87
--- /dev/null
+++ b/fs/btrfs/file-item.c
@@ -0,0 +1,1304 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Oracle. All rights reserved.
+ */
+
+#include <linux/bio.h>
+#include <linux/slab.h>
+#include <linux/pagemap.h>
+#include <linux/highmem.h>
+#include <linux/sched/mm.h>
+#include <crypto/hash.h>
+#include "misc.h"
+#include "ctree.h"
+#include "disk-io.h"
+#include "transaction.h"
+#include "volumes.h"
+#include "print-tree.h"
+#include "compression.h"
+
+#define __MAX_CSUM_ITEMS(r, size) ((unsigned long)(((BTRFS_LEAF_DATA_SIZE(r) - \
+ sizeof(struct btrfs_item) * 2) / \
+ size) - 1))
+
+#define MAX_CSUM_ITEMS(r, size) (min_t(u32, __MAX_CSUM_ITEMS(r, size), \
+ PAGE_SIZE))
+
+/**
+ * Set inode's size according to filesystem options
+ *
+ * @inode: inode we want to update the disk_i_size for
+ * @new_i_size: i_size we want to set to, 0 if we use i_size
+ *
+ * With NO_HOLES set this simply sets the disk_is_size to whatever i_size_read()
+ * returns as it is perfectly fine with a file that has holes without hole file
+ * extent items.
+ *
+ * However without NO_HOLES we need to only return the area that is contiguous
+ * from the 0 offset of the file. Otherwise we could end up adjust i_size up
+ * to an extent that has a gap in between.
+ *
+ * Finally new_i_size should only be set in the case of truncate where we're not
+ * ready to use i_size_read() as the limiter yet.
+ */
+void btrfs_inode_safe_disk_i_size_write(struct btrfs_inode *inode, u64 new_i_size)
+{
+ struct btrfs_fs_info *fs_info = inode->root->fs_info;
+ u64 start, end, i_size;
+ int ret;
+
+ spin_lock(&inode->lock);
+ i_size = new_i_size ?: i_size_read(&inode->vfs_inode);
+ if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
+ inode->disk_i_size = i_size;
+ goto out_unlock;
+ }
+
+ ret = find_contiguous_extent_bit(&inode->file_extent_tree, 0, &start,
+ &end, EXTENT_DIRTY);
+ if (!ret && start == 0)
+ i_size = min(i_size, end + 1);
+ else
+ i_size = 0;
+ inode->disk_i_size = i_size;
+out_unlock:
+ spin_unlock(&inode->lock);
+}
+
+/**
+ * Mark range within a file as having a new extent inserted
+ *
+ * @inode: inode being modified
+ * @start: start file offset of the file extent we've inserted
+ * @len: logical length of the file extent item
+ *
+ * Call when we are inserting a new file extent where there was none before.
+ * Does not need to call this in the case where we're replacing an existing file
+ * extent, however if not sure it's fine to call this multiple times.
+ *
+ * The start and len must match the file extent item, so thus must be sectorsize
+ * aligned.
+ */
+int btrfs_inode_set_file_extent_range(struct btrfs_inode *inode, u64 start,
+ u64 len)
+{
+ if (len == 0)
+ return 0;
+
+ ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize));
+
+ if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
+ return 0;
+ return set_extent_bits(&inode->file_extent_tree, start, start + len - 1,
+ EXTENT_DIRTY);
+}
+
+/**
+ * Marks an inode range as not having a backing extent
+ *
+ * @inode: inode being modified
+ * @start: start file offset of the file extent we've inserted
+ * @len: logical length of the file extent item
+ *
+ * Called when we drop a file extent, for example when we truncate. Doesn't
+ * need to be called for cases where we're replacing a file extent, like when
+ * we've COWed a file extent.
+ *
+ * The start and len must match the file extent item, so thus must be sectorsize
+ * aligned.
+ */
+int btrfs_inode_clear_file_extent_range(struct btrfs_inode *inode, u64 start,
+ u64 len)
+{
+ if (len == 0)
+ return 0;
+
+ ASSERT(IS_ALIGNED(start + len, inode->root->fs_info->sectorsize) ||
+ len == (u64)-1);
+
+ if (btrfs_fs_incompat(inode->root->fs_info, NO_HOLES))
+ return 0;
+ return clear_extent_bit(&inode->file_extent_tree, start,
+ start + len - 1, EXTENT_DIRTY, NULL);
+}
+
+static inline u32 max_ordered_sum_bytes(struct btrfs_fs_info *fs_info,
+ u16 csum_size)
+{
+ u32 ncsums = (PAGE_SIZE - sizeof(struct btrfs_ordered_sum)) / csum_size;
+
+ return ncsums * fs_info->sectorsize;
+}
+
+/*
+ * Calculate the total size needed to allocate for an ordered sum structure
+ * spanning @bytes in the file.
+ */
+static int btrfs_ordered_sum_size(struct btrfs_fs_info *fs_info, unsigned long bytes)
+{
+ int num_sectors = (int)DIV_ROUND_UP(bytes, fs_info->sectorsize);
+
+ return sizeof(struct btrfs_ordered_sum) + num_sectors * fs_info->csum_size;
+}
+
+int btrfs_insert_hole_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 objectid, u64 pos, u64 num_bytes)
+{
+ int ret = 0;
+ struct btrfs_file_extent_item *item;
+ struct btrfs_key file_key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+ file_key.objectid = objectid;
+ file_key.offset = pos;
+ file_key.type = BTRFS_EXTENT_DATA_KEY;
+
+ ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+ sizeof(*item));
+ if (ret < 0)
+ goto out;
+ BUG_ON(ret); /* Can't happen */
+ leaf = path->nodes[0];
+ item = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_file_extent_item);
+ btrfs_set_file_extent_disk_bytenr(leaf, item, 0);
+ btrfs_set_file_extent_disk_num_bytes(leaf, item, 0);
+ btrfs_set_file_extent_offset(leaf, item, 0);
+ btrfs_set_file_extent_num_bytes(leaf, item, num_bytes);
+ btrfs_set_file_extent_ram_bytes(leaf, item, num_bytes);
+ btrfs_set_file_extent_generation(leaf, item, trans->transid);
+ btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
+ btrfs_set_file_extent_compression(leaf, item, 0);
+ btrfs_set_file_extent_encryption(leaf, item, 0);
+ btrfs_set_file_extent_other_encoding(leaf, item, 0);
+
+ btrfs_mark_buffer_dirty(leaf);
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static struct btrfs_csum_item *
+btrfs_lookup_csum(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 bytenr, int cow)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ int ret;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_csum_item *item;
+ struct extent_buffer *leaf;
+ u64 csum_offset = 0;
+ const u32 csum_size = fs_info->csum_size;
+ int csums_in_item;
+
+ file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ file_key.offset = bytenr;
+ file_key.type = BTRFS_EXTENT_CSUM_KEY;
+ ret = btrfs_search_slot(trans, root, &file_key, path, 0, cow);
+ if (ret < 0)
+ goto fail;
+ leaf = path->nodes[0];
+ if (ret > 0) {
+ ret = 1;
+ if (path->slots[0] == 0)
+ goto fail;
+ path->slots[0]--;
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ if (found_key.type != BTRFS_EXTENT_CSUM_KEY)
+ goto fail;
+
+ csum_offset = (bytenr - found_key.offset) >>
+ fs_info->sectorsize_bits;
+ csums_in_item = btrfs_item_size(leaf, path->slots[0]);
+ csums_in_item /= csum_size;
+
+ if (csum_offset == csums_in_item) {
+ ret = -EFBIG;
+ goto fail;
+ } else if (csum_offset > csums_in_item) {
+ goto fail;
+ }
+ }
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * csum_size);
+ return item;
+fail:
+ if (ret > 0)
+ ret = -ENOENT;
+ return ERR_PTR(ret);
+}
+
+int btrfs_lookup_file_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_path *path, u64 objectid,
+ u64 offset, int mod)
+{
+ struct btrfs_key file_key;
+ int ins_len = mod < 0 ? -1 : 0;
+ int cow = mod != 0;
+
+ file_key.objectid = objectid;
+ file_key.offset = offset;
+ file_key.type = BTRFS_EXTENT_DATA_KEY;
+
+ return btrfs_search_slot(trans, root, &file_key, path, ins_len, cow);
+}
+
+/*
+ * Find checksums for logical bytenr range [disk_bytenr, disk_bytenr + len) and
+ * estore the result to @dst.
+ *
+ * Return >0 for the number of sectors we found.
+ * Return 0 for the range [disk_bytenr, disk_bytenr + sectorsize) has no csum
+ * for it. Caller may want to try next sector until one range is hit.
+ * Return <0 for fatal error.
+ */
+static int search_csum_tree(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 disk_bytenr,
+ u64 len, u8 *dst)
+{
+ struct btrfs_root *csum_root;
+ struct btrfs_csum_item *item = NULL;
+ struct btrfs_key key;
+ const u32 sectorsize = fs_info->sectorsize;
+ const u32 csum_size = fs_info->csum_size;
+ u32 itemsize;
+ int ret;
+ u64 csum_start;
+ u64 csum_len;
+
+ ASSERT(IS_ALIGNED(disk_bytenr, sectorsize) &&
+ IS_ALIGNED(len, sectorsize));
+
+ /* Check if the current csum item covers disk_bytenr */
+ if (path->nodes[0]) {
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_csum_item);
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
+
+ csum_start = key.offset;
+ csum_len = (itemsize / csum_size) * sectorsize;
+
+ if (in_range(disk_bytenr, csum_start, csum_len))
+ goto found;
+ }
+
+ /* Current item doesn't contain the desired range, search again */
+ btrfs_release_path(path);
+ csum_root = btrfs_csum_root(fs_info, disk_bytenr);
+ item = btrfs_lookup_csum(NULL, csum_root, path, disk_bytenr, 0);
+ if (IS_ERR(item)) {
+ ret = PTR_ERR(item);
+ goto out;
+ }
+ btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
+ itemsize = btrfs_item_size(path->nodes[0], path->slots[0]);
+
+ csum_start = key.offset;
+ csum_len = (itemsize / csum_size) * sectorsize;
+ ASSERT(in_range(disk_bytenr, csum_start, csum_len));
+
+found:
+ ret = (min(csum_start + csum_len, disk_bytenr + len) -
+ disk_bytenr) >> fs_info->sectorsize_bits;
+ read_extent_buffer(path->nodes[0], dst, (unsigned long)item,
+ ret * csum_size);
+out:
+ if (ret == -ENOENT || ret == -EFBIG)
+ ret = 0;
+ return ret;
+}
+
+/*
+ * Locate the file_offset of @cur_disk_bytenr of a @bio.
+ *
+ * Bio of btrfs represents read range of
+ * [bi_sector << 9, bi_sector << 9 + bi_size).
+ * Knowing this, we can iterate through each bvec to locate the page belong to
+ * @cur_disk_bytenr and get the file offset.
+ *
+ * @inode is used to determine if the bvec page really belongs to @inode.
+ *
+ * Return 0 if we can't find the file offset
+ * Return >0 if we find the file offset and restore it to @file_offset_ret
+ */
+static int search_file_offset_in_bio(struct bio *bio, struct inode *inode,
+ u64 disk_bytenr, u64 *file_offset_ret)
+{
+ struct bvec_iter iter;
+ struct bio_vec bvec;
+ u64 cur = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+ int ret = 0;
+
+ bio_for_each_segment(bvec, bio, iter) {
+ struct page *page = bvec.bv_page;
+
+ if (cur > disk_bytenr)
+ break;
+ if (cur + bvec.bv_len <= disk_bytenr) {
+ cur += bvec.bv_len;
+ continue;
+ }
+ ASSERT(in_range(disk_bytenr, cur, bvec.bv_len));
+ if (page->mapping && page->mapping->host &&
+ page->mapping->host == inode) {
+ ret = 1;
+ *file_offset_ret = page_offset(page) + bvec.bv_offset +
+ disk_bytenr - cur;
+ break;
+ }
+ }
+ return ret;
+}
+
+/**
+ * Lookup the checksum for the read bio in csum tree.
+ *
+ * @inode: inode that the bio is for.
+ * @bio: bio to look up.
+ * @dst: Buffer of size nblocks * btrfs_super_csum_size() used to return
+ * checksum (nblocks = bio->bi_iter.bi_size / fs_info->sectorsize). If
+ * NULL, the checksum buffer is allocated and returned in
+ * btrfs_bio(bio)->csum instead.
+ *
+ * Return: BLK_STS_RESOURCE if allocating memory fails, BLK_STS_OK otherwise.
+ */
+blk_status_t btrfs_lookup_bio_sums(struct inode *inode, struct bio *bio, u8 *dst)
+{
+ struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+ struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
+ struct btrfs_bio *bbio = NULL;
+ struct btrfs_path *path;
+ const u32 sectorsize = fs_info->sectorsize;
+ const u32 csum_size = fs_info->csum_size;
+ u32 orig_len = bio->bi_iter.bi_size;
+ u64 orig_disk_bytenr = bio->bi_iter.bi_sector << SECTOR_SHIFT;
+ u64 cur_disk_bytenr;
+ u8 *csum;
+ const unsigned int nblocks = orig_len >> fs_info->sectorsize_bits;
+ int count = 0;
+ blk_status_t ret = BLK_STS_OK;
+
+ if ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM) ||
+ test_bit(BTRFS_FS_STATE_NO_CSUMS, &fs_info->fs_state))
+ return BLK_STS_OK;
+
+ /*
+ * This function is only called for read bio.
+ *
+ * This means two things:
+ * - All our csums should only be in csum tree
+ * No ordered extents csums, as ordered extents are only for write
+ * path.
+ * - No need to bother any other info from bvec
+ * Since we're looking up csums, the only important info is the
+ * disk_bytenr and the length, which can be extracted from bi_iter
+ * directly.
+ */
+ ASSERT(bio_op(bio) == REQ_OP_READ);
+ path = btrfs_alloc_path();
+ if (!path)
+ return BLK_STS_RESOURCE;
+
+ if (!dst) {
+ bbio = btrfs_bio(bio);
+
+ if (nblocks * csum_size > BTRFS_BIO_INLINE_CSUM_SIZE) {
+ bbio->csum = kmalloc_array(nblocks, csum_size, GFP_NOFS);
+ if (!bbio->csum) {
+ btrfs_free_path(path);
+ return BLK_STS_RESOURCE;
+ }
+ } else {
+ bbio->csum = bbio->csum_inline;
+ }
+ csum = bbio->csum;
+ } else {
+ csum = dst;
+ }
+
+ /*
+ * If requested number of sectors is larger than one leaf can contain,
+ * kick the readahead for csum tree.
+ */
+ if (nblocks > fs_info->csums_per_leaf)
+ path->reada = READA_FORWARD;
+
+ /*
+ * the free space stuff is only read when it hasn't been
+ * updated in the current transaction. So, we can safely
+ * read from the commit root and sidestep a nasty deadlock
+ * between reading the free space cache and updating the csum tree.
+ */
+ if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
+ path->search_commit_root = 1;
+ path->skip_locking = 1;
+ }
+
+ for (cur_disk_bytenr = orig_disk_bytenr;
+ cur_disk_bytenr < orig_disk_bytenr + orig_len;
+ cur_disk_bytenr += (count * sectorsize)) {
+ u64 search_len = orig_disk_bytenr + orig_len - cur_disk_bytenr;
+ unsigned int sector_offset;
+ u8 *csum_dst;
+
+ /*
+ * Although both cur_disk_bytenr and orig_disk_bytenr is u64,
+ * we're calculating the offset to the bio start.
+ *
+ * Bio size is limited to UINT_MAX, thus unsigned int is large
+ * enough to contain the raw result, not to mention the right
+ * shifted result.
+ */
+ ASSERT(cur_disk_bytenr - orig_disk_bytenr < UINT_MAX);
+ sector_offset = (cur_disk_bytenr - orig_disk_bytenr) >>
+ fs_info->sectorsize_bits;
+ csum_dst = csum + sector_offset * csum_size;
+
+ count = search_csum_tree(fs_info, path, cur_disk_bytenr,
+ search_len, csum_dst);
+ if (count < 0) {
+ ret = errno_to_blk_status(count);
+ if (bbio)
+ btrfs_bio_free_csum(bbio);
+ break;
+ }
+
+ /*
+ * We didn't find a csum for this range. We need to make sure
+ * we complain loudly about this, because we are not NODATASUM.
+ *
+ * However for the DATA_RELOC inode we could potentially be
+ * relocating data extents for a NODATASUM inode, so the inode
+ * itself won't be marked with NODATASUM, but the extent we're
+ * copying is in fact NODATASUM. If we don't find a csum we
+ * assume this is the case.
+ */
+ if (count == 0) {
+ memset(csum_dst, 0, csum_size);
+ count = 1;
+
+ if (BTRFS_I(inode)->root->root_key.objectid ==
+ BTRFS_DATA_RELOC_TREE_OBJECTID) {
+ u64 file_offset;
+ int ret;
+
+ ret = search_file_offset_in_bio(bio, inode,
+ cur_disk_bytenr, &file_offset);
+ if (ret)
+ set_extent_bits(io_tree, file_offset,
+ file_offset + sectorsize - 1,
+ EXTENT_NODATASUM);
+ } else {
+ btrfs_warn_rl(fs_info,
+ "csum hole found for disk bytenr range [%llu, %llu)",
+ cur_disk_bytenr, cur_disk_bytenr + sectorsize);
+ }
+ }
+ }
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+int btrfs_lookup_csums_range(struct btrfs_root *root, u64 start, u64 end,
+ struct list_head *list, int search_commit,
+ bool nowait)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_key key;
+ struct btrfs_path *path;
+ struct extent_buffer *leaf;
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_csum_item *item;
+ LIST_HEAD(tmplist);
+ unsigned long offset;
+ int ret;
+ size_t size;
+ u64 csum_end;
+ const u32 csum_size = fs_info->csum_size;
+
+ ASSERT(IS_ALIGNED(start, fs_info->sectorsize) &&
+ IS_ALIGNED(end + 1, fs_info->sectorsize));
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ path->nowait = nowait;
+ if (search_commit) {
+ path->skip_locking = 1;
+ path->reada = READA_FORWARD;
+ path->search_commit_root = 1;
+ }
+
+ key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key.offset = start;
+ key.type = BTRFS_EXTENT_CSUM_KEY;
+
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret < 0)
+ goto fail;
+ if (ret > 0 && path->slots[0] > 0) {
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
+ if (key.objectid == BTRFS_EXTENT_CSUM_OBJECTID &&
+ key.type == BTRFS_EXTENT_CSUM_KEY) {
+ offset = (start - key.offset) >> fs_info->sectorsize_bits;
+ if (offset * csum_size <
+ btrfs_item_size(leaf, path->slots[0] - 1))
+ path->slots[0]--;
+ }
+ }
+
+ while (start <= end) {
+ leaf = path->nodes[0];
+ if (path->slots[0] >= btrfs_header_nritems(leaf)) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0)
+ goto fail;
+ if (ret > 0)
+ break;
+ leaf = path->nodes[0];
+ }
+
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+ if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
+ key.type != BTRFS_EXTENT_CSUM_KEY ||
+ key.offset > end)
+ break;
+
+ if (key.offset > start)
+ start = key.offset;
+
+ size = btrfs_item_size(leaf, path->slots[0]);
+ csum_end = key.offset + (size / csum_size) * fs_info->sectorsize;
+ if (csum_end <= start) {
+ path->slots[0]++;
+ continue;
+ }
+
+ csum_end = min(csum_end, end + 1);
+ item = btrfs_item_ptr(path->nodes[0], path->slots[0],
+ struct btrfs_csum_item);
+ while (start < csum_end) {
+ size = min_t(size_t, csum_end - start,
+ max_ordered_sum_bytes(fs_info, csum_size));
+ sums = kzalloc(btrfs_ordered_sum_size(fs_info, size),
+ GFP_NOFS);
+ if (!sums) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ sums->bytenr = start;
+ sums->len = size;
+
+ offset = (start - key.offset) >> fs_info->sectorsize_bits;
+ offset *= csum_size;
+ size >>= fs_info->sectorsize_bits;
+
+ read_extent_buffer(path->nodes[0],
+ sums->sums,
+ ((unsigned long)item) + offset,
+ csum_size * size);
+
+ start += fs_info->sectorsize * size;
+ list_add_tail(&sums->list, &tmplist);
+ }
+ path->slots[0]++;
+ }
+ ret = 0;
+fail:
+ while (ret < 0 && !list_empty(&tmplist)) {
+ sums = list_entry(tmplist.next, struct btrfs_ordered_sum, list);
+ list_del(&sums->list);
+ kfree(sums);
+ }
+ list_splice_tail(&tmplist, list);
+
+ btrfs_free_path(path);
+ return ret;
+}
+
+/**
+ * Calculate checksums of the data contained inside a bio
+ *
+ * @inode: Owner of the data inside the bio
+ * @bio: Contains the data to be checksummed
+ * @offset: If (u64)-1, @bio may contain discontiguous bio vecs, so the
+ * file offsets are determined from the page offsets in the bio.
+ * Otherwise, this is the starting file offset of the bio vecs in
+ * @bio, which must be contiguous.
+ * @one_ordered: If true, @bio only refers to one ordered extent.
+ */
+blk_status_t btrfs_csum_one_bio(struct btrfs_inode *inode, struct bio *bio,
+ u64 offset, bool one_ordered)
+{
+ struct btrfs_fs_info *fs_info = inode->root->fs_info;
+ SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
+ struct btrfs_ordered_sum *sums;
+ struct btrfs_ordered_extent *ordered = NULL;
+ const bool use_page_offsets = (offset == (u64)-1);
+ char *data;
+ struct bvec_iter iter;
+ struct bio_vec bvec;
+ int index;
+ unsigned int blockcount;
+ unsigned long total_bytes = 0;
+ unsigned long this_sum_bytes = 0;
+ int i;
+ unsigned nofs_flag;
+
+ nofs_flag = memalloc_nofs_save();
+ sums = kvzalloc(btrfs_ordered_sum_size(fs_info, bio->bi_iter.bi_size),
+ GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
+
+ if (!sums)
+ return BLK_STS_RESOURCE;
+
+ sums->len = bio->bi_iter.bi_size;
+ INIT_LIST_HEAD(&sums->list);
+
+ sums->bytenr = bio->bi_iter.bi_sector << 9;
+ index = 0;
+
+ shash->tfm = fs_info->csum_shash;
+
+ bio_for_each_segment(bvec, bio, iter) {
+ if (use_page_offsets)
+ offset = page_offset(bvec.bv_page) + bvec.bv_offset;
+
+ if (!ordered) {
+ ordered = btrfs_lookup_ordered_extent(inode, offset);
+ /*
+ * The bio range is not covered by any ordered extent,
+ * must be a code logic error.
+ */
+ if (unlikely(!ordered)) {
+ WARN(1, KERN_WARNING
+ "no ordered extent for root %llu ino %llu offset %llu\n",
+ inode->root->root_key.objectid,
+ btrfs_ino(inode), offset);
+ kvfree(sums);
+ return BLK_STS_IOERR;
+ }
+ }
+
+ blockcount = BTRFS_BYTES_TO_BLKS(fs_info,
+ bvec.bv_len + fs_info->sectorsize
+ - 1);
+
+ for (i = 0; i < blockcount; i++) {
+ if (!one_ordered &&
+ !in_range(offset, ordered->file_offset,
+ ordered->num_bytes)) {
+ unsigned long bytes_left;
+
+ sums->len = this_sum_bytes;
+ this_sum_bytes = 0;
+ btrfs_add_ordered_sum(ordered, sums);
+ btrfs_put_ordered_extent(ordered);
+
+ bytes_left = bio->bi_iter.bi_size - total_bytes;
+
+ nofs_flag = memalloc_nofs_save();
+ sums = kvzalloc(btrfs_ordered_sum_size(fs_info,
+ bytes_left), GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
+ if (!sums)
+ return BLK_STS_RESOURCE;
+
+ sums->len = bytes_left;
+ ordered = btrfs_lookup_ordered_extent(inode,
+ offset);
+ ASSERT(ordered); /* Logic error */
+ sums->bytenr = (bio->bi_iter.bi_sector << 9)
+ + total_bytes;
+ index = 0;
+ }
+
+ data = bvec_kmap_local(&bvec);
+ crypto_shash_digest(shash,
+ data + (i * fs_info->sectorsize),
+ fs_info->sectorsize,
+ sums->sums + index);
+ kunmap_local(data);
+ index += fs_info->csum_size;
+ offset += fs_info->sectorsize;
+ this_sum_bytes += fs_info->sectorsize;
+ total_bytes += fs_info->sectorsize;
+ }
+
+ }
+ this_sum_bytes = 0;
+ btrfs_add_ordered_sum(ordered, sums);
+ btrfs_put_ordered_extent(ordered);
+ return 0;
+}
+
+/*
+ * helper function for csum removal, this expects the
+ * key to describe the csum pointed to by the path, and it expects
+ * the csum to overlap the range [bytenr, len]
+ *
+ * The csum should not be entirely contained in the range and the
+ * range should not be entirely contained in the csum.
+ *
+ * This calls btrfs_truncate_item with the correct args based on the
+ * overlap, and fixes up the key as required.
+ */
+static noinline void truncate_one_csum(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path,
+ struct btrfs_key *key,
+ u64 bytenr, u64 len)
+{
+ struct extent_buffer *leaf;
+ const u32 csum_size = fs_info->csum_size;
+ u64 csum_end;
+ u64 end_byte = bytenr + len;
+ u32 blocksize_bits = fs_info->sectorsize_bits;
+
+ leaf = path->nodes[0];
+ csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
+ csum_end <<= blocksize_bits;
+ csum_end += key->offset;
+
+ if (key->offset < bytenr && csum_end <= end_byte) {
+ /*
+ * [ bytenr - len ]
+ * [ ]
+ * [csum ]
+ * A simple truncate off the end of the item
+ */
+ u32 new_size = (bytenr - key->offset) >> blocksize_bits;
+ new_size *= csum_size;
+ btrfs_truncate_item(path, new_size, 1);
+ } else if (key->offset >= bytenr && csum_end > end_byte &&
+ end_byte > key->offset) {
+ /*
+ * [ bytenr - len ]
+ * [ ]
+ * [csum ]
+ * we need to truncate from the beginning of the csum
+ */
+ u32 new_size = (csum_end - end_byte) >> blocksize_bits;
+ new_size *= csum_size;
+
+ btrfs_truncate_item(path, new_size, 0);
+
+ key->offset = end_byte;
+ btrfs_set_item_key_safe(fs_info, path, key);
+ } else {
+ BUG();
+ }
+}
+
+/*
+ * deletes the csum items from the csum tree for a given
+ * range of bytes.
+ */
+int btrfs_del_csums(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, u64 bytenr, u64 len)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ u64 end_byte = bytenr + len;
+ u64 csum_end;
+ struct extent_buffer *leaf;
+ int ret = 0;
+ const u32 csum_size = fs_info->csum_size;
+ u32 blocksize_bits = fs_info->sectorsize_bits;
+
+ ASSERT(root->root_key.objectid == BTRFS_CSUM_TREE_OBJECTID ||
+ root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID);
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+
+ while (1) {
+ key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ key.offset = end_byte - 1;
+ key.type = BTRFS_EXTENT_CSUM_KEY;
+
+ ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
+ if (ret > 0) {
+ ret = 0;
+ if (path->slots[0] == 0)
+ break;
+ path->slots[0]--;
+ } else if (ret < 0) {
+ break;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
+
+ if (key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
+ key.type != BTRFS_EXTENT_CSUM_KEY) {
+ break;
+ }
+
+ if (key.offset >= end_byte)
+ break;
+
+ csum_end = btrfs_item_size(leaf, path->slots[0]) / csum_size;
+ csum_end <<= blocksize_bits;
+ csum_end += key.offset;
+
+ /* this csum ends before we start, we're done */
+ if (csum_end <= bytenr)
+ break;
+
+ /* delete the entire item, it is inside our range */
+ if (key.offset >= bytenr && csum_end <= end_byte) {
+ int del_nr = 1;
+
+ /*
+ * Check how many csum items preceding this one in this
+ * leaf correspond to our range and then delete them all
+ * at once.
+ */
+ if (key.offset > bytenr && path->slots[0] > 0) {
+ int slot = path->slots[0] - 1;
+
+ while (slot >= 0) {
+ struct btrfs_key pk;
+
+ btrfs_item_key_to_cpu(leaf, &pk, slot);
+ if (pk.offset < bytenr ||
+ pk.type != BTRFS_EXTENT_CSUM_KEY ||
+ pk.objectid !=
+ BTRFS_EXTENT_CSUM_OBJECTID)
+ break;
+ path->slots[0] = slot;
+ del_nr++;
+ key.offset = pk.offset;
+ slot--;
+ }
+ }
+ ret = btrfs_del_items(trans, root, path,
+ path->slots[0], del_nr);
+ if (ret)
+ break;
+ if (key.offset == bytenr)
+ break;
+ } else if (key.offset < bytenr && csum_end > end_byte) {
+ unsigned long offset;
+ unsigned long shift_len;
+ unsigned long item_offset;
+ /*
+ * [ bytenr - len ]
+ * [csum ]
+ *
+ * Our bytes are in the middle of the csum,
+ * we need to split this item and insert a new one.
+ *
+ * But we can't drop the path because the
+ * csum could change, get removed, extended etc.
+ *
+ * The trick here is the max size of a csum item leaves
+ * enough room in the tree block for a single
+ * item header. So, we split the item in place,
+ * adding a new header pointing to the existing
+ * bytes. Then we loop around again and we have
+ * a nicely formed csum item that we can neatly
+ * truncate.
+ */
+ offset = (bytenr - key.offset) >> blocksize_bits;
+ offset *= csum_size;
+
+ shift_len = (len >> blocksize_bits) * csum_size;
+
+ item_offset = btrfs_item_ptr_offset(leaf,
+ path->slots[0]);
+
+ memzero_extent_buffer(leaf, item_offset + offset,
+ shift_len);
+ key.offset = bytenr;
+
+ /*
+ * btrfs_split_item returns -EAGAIN when the
+ * item changed size or key
+ */
+ ret = btrfs_split_item(trans, root, path, &key, offset);
+ if (ret && ret != -EAGAIN) {
+ btrfs_abort_transaction(trans, ret);
+ break;
+ }
+ ret = 0;
+
+ key.offset = end_byte - 1;
+ } else {
+ truncate_one_csum(fs_info, path, &key, bytenr, len);
+ if (key.offset < bytenr)
+ break;
+ }
+ btrfs_release_path(path);
+ }
+ btrfs_free_path(path);
+ return ret;
+}
+
+static int find_next_csum_offset(struct btrfs_root *root,
+ struct btrfs_path *path,
+ u64 *next_offset)
+{
+ const u32 nritems = btrfs_header_nritems(path->nodes[0]);
+ struct btrfs_key found_key;
+ int slot = path->slots[0] + 1;
+ int ret;
+
+ if (nritems == 0 || slot >= nritems) {
+ ret = btrfs_next_leaf(root, path);
+ if (ret < 0) {
+ return ret;
+ } else if (ret > 0) {
+ *next_offset = (u64)-1;
+ return 0;
+ }
+ slot = path->slots[0];
+ }
+
+ btrfs_item_key_to_cpu(path->nodes[0], &found_key, slot);
+
+ if (found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
+ found_key.type != BTRFS_EXTENT_CSUM_KEY)
+ *next_offset = (u64)-1;
+ else
+ *next_offset = found_key.offset;
+
+ return 0;
+}
+
+int btrfs_csum_file_blocks(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct btrfs_ordered_sum *sums)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_key file_key;
+ struct btrfs_key found_key;
+ struct btrfs_path *path;
+ struct btrfs_csum_item *item;
+ struct btrfs_csum_item *item_end;
+ struct extent_buffer *leaf = NULL;
+ u64 next_offset;
+ u64 total_bytes = 0;
+ u64 csum_offset;
+ u64 bytenr;
+ u32 ins_size;
+ int index = 0;
+ int found_next;
+ int ret;
+ const u32 csum_size = fs_info->csum_size;
+
+ path = btrfs_alloc_path();
+ if (!path)
+ return -ENOMEM;
+again:
+ next_offset = (u64)-1;
+ found_next = 0;
+ bytenr = sums->bytenr + total_bytes;
+ file_key.objectid = BTRFS_EXTENT_CSUM_OBJECTID;
+ file_key.offset = bytenr;
+ file_key.type = BTRFS_EXTENT_CSUM_KEY;
+
+ item = btrfs_lookup_csum(trans, root, path, bytenr, 1);
+ if (!IS_ERR(item)) {
+ ret = 0;
+ leaf = path->nodes[0];
+ item_end = btrfs_item_ptr(leaf, path->slots[0],
+ struct btrfs_csum_item);
+ item_end = (struct btrfs_csum_item *)((char *)item_end +
+ btrfs_item_size(leaf, path->slots[0]));
+ goto found;
+ }
+ ret = PTR_ERR(item);
+ if (ret != -EFBIG && ret != -ENOENT)
+ goto out;
+
+ if (ret == -EFBIG) {
+ u32 item_size;
+ /* we found one, but it isn't big enough yet */
+ leaf = path->nodes[0];
+ item_size = btrfs_item_size(leaf, path->slots[0]);
+ if ((item_size / csum_size) >=
+ MAX_CSUM_ITEMS(fs_info, csum_size)) {
+ /* already at max size, make a new one */
+ goto insert;
+ }
+ } else {
+ /* We didn't find a csum item, insert one. */
+ ret = find_next_csum_offset(root, path, &next_offset);
+ if (ret < 0)
+ goto out;
+ found_next = 1;
+ goto insert;
+ }
+
+ /*
+ * At this point, we know the tree has a checksum item that ends at an
+ * offset matching the start of the checksum range we want to insert.
+ * We try to extend that item as much as possible and then add as many
+ * checksums to it as they fit.
+ *
+ * First check if the leaf has enough free space for at least one
+ * checksum. If it has go directly to the item extension code, otherwise
+ * release the path and do a search for insertion before the extension.
+ */
+ if (btrfs_leaf_free_space(leaf) >= csum_size) {
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ csum_offset = (bytenr - found_key.offset) >>
+ fs_info->sectorsize_bits;
+ goto extend_csum;
+ }
+
+ btrfs_release_path(path);
+ path->search_for_extension = 1;
+ ret = btrfs_search_slot(trans, root, &file_key, path,
+ csum_size, 1);
+ path->search_for_extension = 0;
+ if (ret < 0)
+ goto out;
+
+ if (ret > 0) {
+ if (path->slots[0] == 0)
+ goto insert;
+ path->slots[0]--;
+ }
+
+ leaf = path->nodes[0];
+ btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
+ csum_offset = (bytenr - found_key.offset) >> fs_info->sectorsize_bits;
+
+ if (found_key.type != BTRFS_EXTENT_CSUM_KEY ||
+ found_key.objectid != BTRFS_EXTENT_CSUM_OBJECTID ||
+ csum_offset >= MAX_CSUM_ITEMS(fs_info, csum_size)) {
+ goto insert;
+ }
+
+extend_csum:
+ if (csum_offset == btrfs_item_size(leaf, path->slots[0]) /
+ csum_size) {
+ int extend_nr;
+ u64 tmp;
+ u32 diff;
+
+ tmp = sums->len - total_bytes;
+ tmp >>= fs_info->sectorsize_bits;
+ WARN_ON(tmp < 1);
+ extend_nr = max_t(int, 1, tmp);
+
+ /*
+ * A log tree can already have checksum items with a subset of
+ * the checksums we are trying to log. This can happen after
+ * doing a sequence of partial writes into prealloc extents and
+ * fsyncs in between, with a full fsync logging a larger subrange
+ * of an extent for which a previous fast fsync logged a smaller
+ * subrange. And this happens in particular due to merging file
+ * extent items when we complete an ordered extent for a range
+ * covered by a prealloc extent - this is done at
+ * btrfs_mark_extent_written().
+ *
+ * So if we try to extend the previous checksum item, which has
+ * a range that ends at the start of the range we want to insert,
+ * make sure we don't extend beyond the start offset of the next
+ * checksum item. If we are at the last item in the leaf, then
+ * forget the optimization of extending and add a new checksum
+ * item - it is not worth the complexity of releasing the path,
+ * getting the first key for the next leaf, repeat the btree
+ * search, etc, because log trees are temporary anyway and it
+ * would only save a few bytes of leaf space.
+ */
+ if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) {
+ if (path->slots[0] + 1 >=
+ btrfs_header_nritems(path->nodes[0])) {
+ ret = find_next_csum_offset(root, path, &next_offset);
+ if (ret < 0)
+ goto out;
+ found_next = 1;
+ goto insert;
+ }
+
+ ret = find_next_csum_offset(root, path, &next_offset);
+ if (ret < 0)
+ goto out;
+
+ tmp = (next_offset - bytenr) >> fs_info->sectorsize_bits;
+ if (tmp <= INT_MAX)
+ extend_nr = min_t(int, extend_nr, tmp);
+ }
+
+ diff = (csum_offset + extend_nr) * csum_size;
+ diff = min(diff,
+ MAX_CSUM_ITEMS(fs_info, csum_size) * csum_size);
+
+ diff = diff - btrfs_item_size(leaf, path->slots[0]);
+ diff = min_t(u32, btrfs_leaf_free_space(leaf), diff);
+ diff /= csum_size;
+ diff *= csum_size;
+
+ btrfs_extend_item(path, diff);
+ ret = 0;
+ goto csum;
+ }
+
+insert:
+ btrfs_release_path(path);
+ csum_offset = 0;
+ if (found_next) {
+ u64 tmp;
+
+ tmp = sums->len - total_bytes;
+ tmp >>= fs_info->sectorsize_bits;
+ tmp = min(tmp, (next_offset - file_key.offset) >>
+ fs_info->sectorsize_bits);
+
+ tmp = max_t(u64, 1, tmp);
+ tmp = min_t(u64, tmp, MAX_CSUM_ITEMS(fs_info, csum_size));
+ ins_size = csum_size * tmp;
+ } else {
+ ins_size = csum_size;
+ }
+ ret = btrfs_insert_empty_item(trans, root, path, &file_key,
+ ins_size);
+ if (ret < 0)
+ goto out;
+ if (WARN_ON(ret != 0))
+ goto out;
+ leaf = path->nodes[0];
+csum:
+ item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_csum_item);
+ item_end = (struct btrfs_csum_item *)((unsigned char *)item +
+ btrfs_item_size(leaf, path->slots[0]));
+ item = (struct btrfs_csum_item *)((unsigned char *)item +
+ csum_offset * csum_size);
+found:
+ ins_size = (u32)(sums->len - total_bytes) >> fs_info->sectorsize_bits;
+ ins_size *= csum_size;
+ ins_size = min_t(u32, (unsigned long)item_end - (unsigned long)item,
+ ins_size);
+ write_extent_buffer(leaf, sums->sums + index, (unsigned long)item,
+ ins_size);
+
+ index += ins_size;
+ ins_size /= csum_size;
+ total_bytes += ins_size * fs_info->sectorsize;
+
+ btrfs_mark_buffer_dirty(path->nodes[0]);
+ if (total_bytes < sums->len) {
+ btrfs_release_path(path);
+ cond_resched();
+ goto again;
+ }
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
+ const struct btrfs_path *path,
+ struct btrfs_file_extent_item *fi,
+ const bool new_inline,
+ struct extent_map *em)
+{
+ struct btrfs_fs_info *fs_info = inode->root->fs_info;
+ struct btrfs_root *root = inode->root;
+ struct extent_buffer *leaf = path->nodes[0];
+ const int slot = path->slots[0];
+ struct btrfs_key key;
+ u64 extent_start, extent_end;
+ u64 bytenr;
+ u8 type = btrfs_file_extent_type(leaf, fi);
+ int compress_type = btrfs_file_extent_compression(leaf, fi);
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ extent_start = key.offset;
+ extent_end = btrfs_file_extent_end(path);
+ em->ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
+ em->generation = btrfs_file_extent_generation(leaf, fi);
+ if (type == BTRFS_FILE_EXTENT_REG ||
+ type == BTRFS_FILE_EXTENT_PREALLOC) {
+ em->start = extent_start;
+ em->len = extent_end - extent_start;
+ em->orig_start = extent_start -
+ btrfs_file_extent_offset(leaf, fi);
+ em->orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ if (bytenr == 0) {
+ em->block_start = EXTENT_MAP_HOLE;
+ return;
+ }
+ if (compress_type != BTRFS_COMPRESS_NONE) {
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ em->compress_type = compress_type;
+ em->block_start = bytenr;
+ em->block_len = em->orig_block_len;
+ } else {
+ bytenr += btrfs_file_extent_offset(leaf, fi);
+ em->block_start = bytenr;
+ em->block_len = em->len;
+ if (type == BTRFS_FILE_EXTENT_PREALLOC)
+ set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
+ }
+ } else if (type == BTRFS_FILE_EXTENT_INLINE) {
+ em->block_start = EXTENT_MAP_INLINE;
+ em->start = extent_start;
+ em->len = extent_end - extent_start;
+ /*
+ * Initialize orig_start and block_len with the same values
+ * as in inode.c:btrfs_get_extent().
+ */
+ em->orig_start = EXTENT_MAP_HOLE;
+ em->block_len = (u64)-1;
+ if (!new_inline && compress_type != BTRFS_COMPRESS_NONE) {
+ set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
+ em->compress_type = compress_type;
+ }
+ } else {
+ btrfs_err(fs_info,
+ "unknown file extent item type %d, inode %llu, offset %llu, "
+ "root %llu", type, btrfs_ino(inode), extent_start,
+ root->root_key.objectid);
+ }
+}
+
+/*
+ * Returns the end offset (non inclusive) of the file extent item the given path
+ * points to. If it points to an inline extent, the returned offset is rounded
+ * up to the sector size.
+ */
+u64 btrfs_file_extent_end(const struct btrfs_path *path)
+{
+ const struct extent_buffer *leaf = path->nodes[0];
+ const int slot = path->slots[0];
+ struct btrfs_file_extent_item *fi;
+ struct btrfs_key key;
+ u64 end;
+
+ btrfs_item_key_to_cpu(leaf, &key, slot);
+ ASSERT(key.type == BTRFS_EXTENT_DATA_KEY);
+ fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+
+ if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) {
+ end = btrfs_file_extent_ram_bytes(leaf, fi);
+ end = ALIGN(key.offset + end, leaf->fs_info->sectorsize);
+ } else {
+ end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
+ }
+
+ return end;
+}