diff options
Diffstat (limited to 'fs/ext4/inode.c')
| -rw-r--r-- | fs/ext4/inode.c | 6417 |
1 files changed, 6417 insertions, 0 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c new file mode 100644 index 000000000..76c887108 --- /dev/null +++ b/fs/ext4/inode.c @@ -0,0 +1,6417 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/ext4/inode.c + * + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * + * from + * + * linux/fs/minix/inode.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * 64-bit file support on 64-bit platforms by Jakub Jelinek + * (jj@sunsite.ms.mff.cuni.cz) + * + * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000 + */ + +#include <linux/fs.h> +#include <linux/time.h> +#include <linux/highuid.h> +#include <linux/pagemap.h> +#include <linux/dax.h> +#include <linux/quotaops.h> +#include <linux/string.h> +#include <linux/buffer_head.h> +#include <linux/writeback.h> +#include <linux/pagevec.h> +#include <linux/mpage.h> +#include <linux/namei.h> +#include <linux/uio.h> +#include <linux/bio.h> +#include <linux/workqueue.h> +#include <linux/kernel.h> +#include <linux/printk.h> +#include <linux/slab.h> +#include <linux/bitops.h> +#include <linux/iomap.h> +#include <linux/iversion.h> + +#include "ext4_jbd2.h" +#include "xattr.h" +#include "acl.h" +#include "truncate.h" + +#include <trace/events/ext4.h> + +#define MPAGE_DA_EXTENT_TAIL 0x01 + +static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw, + struct ext4_inode_info *ei) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + __u32 csum; + __u16 dummy_csum = 0; + int offset = offsetof(struct ext4_inode, i_checksum_lo); + unsigned int csum_size = sizeof(dummy_csum); + + csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, offset); + csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, csum_size); + offset += csum_size; + csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset, + EXT4_GOOD_OLD_INODE_SIZE - offset); + + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { + offset = offsetof(struct ext4_inode, i_checksum_hi); + csum = ext4_chksum(sbi, csum, (__u8 *)raw + + EXT4_GOOD_OLD_INODE_SIZE, + offset - EXT4_GOOD_OLD_INODE_SIZE); + if (EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) { + csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, + csum_size); + offset += csum_size; + } + csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset, + EXT4_INODE_SIZE(inode->i_sb) - offset); + } + + return csum; +} + +static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw, + struct ext4_inode_info *ei) +{ + __u32 provided, calculated; + + if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != + cpu_to_le32(EXT4_OS_LINUX) || + !ext4_has_metadata_csum(inode->i_sb)) + return 1; + + provided = le16_to_cpu(raw->i_checksum_lo); + calculated = ext4_inode_csum(inode, raw, ei); + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && + EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) + provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16; + else + calculated &= 0xFFFF; + + return provided == calculated; +} + +static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw, + struct ext4_inode_info *ei) +{ + __u32 csum; + + if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != + cpu_to_le32(EXT4_OS_LINUX) || + !ext4_has_metadata_csum(inode->i_sb)) + return; + + csum = ext4_inode_csum(inode, raw, ei); + raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF); + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && + EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) + raw->i_checksum_hi = cpu_to_le16(csum >> 16); +} + +static inline int ext4_begin_ordered_truncate(struct inode *inode, + loff_t new_size) +{ + trace_ext4_begin_ordered_truncate(inode, new_size); + /* + * If jinode is zero, then we never opened the file for + * writing, so there's no need to call + * jbd2_journal_begin_ordered_truncate() since there's no + * outstanding writes we need to flush. + */ + if (!EXT4_I(inode)->jinode) + return 0; + return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode), + EXT4_I(inode)->jinode, + new_size); +} + +static void ext4_invalidatepage(struct page *page, unsigned int offset, + unsigned int length); +static int __ext4_journalled_writepage(struct page *page, unsigned int len); +static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh); +static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, + int pextents); + +/* + * Test whether an inode is a fast symlink. + * A fast symlink has its symlink data stored in ext4_inode_info->i_data. + */ +int ext4_inode_is_fast_symlink(struct inode *inode) +{ + if (!(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) { + int ea_blocks = EXT4_I(inode)->i_file_acl ? + EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0; + + if (ext4_has_inline_data(inode)) + return 0; + + return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); + } + return S_ISLNK(inode->i_mode) && inode->i_size && + (inode->i_size < EXT4_N_BLOCKS * 4); +} + +/* + * Restart the transaction associated with *handle. This does a commit, + * so before we call here everything must be consistently dirtied against + * this transaction. + */ +int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode, + int nblocks) +{ + int ret; + + /* + * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this + * moment, get_block can be called only for blocks inside i_size since + * page cache has been already dropped and writes are blocked by + * i_mutex. So we can safely drop the i_data_sem here. + */ + BUG_ON(EXT4_JOURNAL(inode) == NULL); + jbd_debug(2, "restarting handle %p\n", handle); + up_write(&EXT4_I(inode)->i_data_sem); + ret = ext4_journal_restart(handle, nblocks); + down_write(&EXT4_I(inode)->i_data_sem); + ext4_discard_preallocations(inode); + + return ret; +} + +/* + * Called at the last iput() if i_nlink is zero. + */ +void ext4_evict_inode(struct inode *inode) +{ + handle_t *handle; + int err; + /* + * Credits for final inode cleanup and freeing: + * sb + inode (ext4_orphan_del()), block bitmap, group descriptor + * (xattr block freeing), bitmap, group descriptor (inode freeing) + */ + int extra_credits = 6; + struct ext4_xattr_inode_array *ea_inode_array = NULL; + bool freeze_protected = false; + + trace_ext4_evict_inode(inode); + + if (inode->i_nlink) { + /* + * When journalling data dirty buffers are tracked only in the + * journal. So although mm thinks everything is clean and + * ready for reaping the inode might still have some pages to + * write in the running transaction or waiting to be + * checkpointed. Thus calling jbd2_journal_invalidatepage() + * (via truncate_inode_pages()) to discard these buffers can + * cause data loss. Also even if we did not discard these + * buffers, we would have no way to find them after the inode + * is reaped and thus user could see stale data if he tries to + * read them before the transaction is checkpointed. So be + * careful and force everything to disk here... We use + * ei->i_datasync_tid to store the newest transaction + * containing inode's data. + * + * Note that directories do not have this problem because they + * don't use page cache. + */ + if (inode->i_ino != EXT4_JOURNAL_INO && + ext4_should_journal_data(inode) && + (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) && + inode->i_data.nrpages) { + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + tid_t commit_tid = EXT4_I(inode)->i_datasync_tid; + + jbd2_complete_transaction(journal, commit_tid); + filemap_write_and_wait(&inode->i_data); + } + truncate_inode_pages_final(&inode->i_data); + + goto no_delete; + } + + if (is_bad_inode(inode)) + goto no_delete; + dquot_initialize(inode); + + if (ext4_should_order_data(inode)) + ext4_begin_ordered_truncate(inode, 0); + truncate_inode_pages_final(&inode->i_data); + + /* + * Protect us against freezing - iput() caller didn't have to have any + * protection against it. When we are in a running transaction though, + * we are already protected against freezing and we cannot grab further + * protection due to lock ordering constraints. + */ + if (!ext4_journal_current_handle()) { + sb_start_intwrite(inode->i_sb); + freeze_protected = true; + } + + if (!IS_NOQUOTA(inode)) + extra_credits += EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb); + + /* + * Block bitmap, group descriptor, and inode are accounted in both + * ext4_blocks_for_truncate() and extra_credits. So subtract 3. + */ + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, + ext4_blocks_for_truncate(inode) + extra_credits - 3); + if (IS_ERR(handle)) { + ext4_std_error(inode->i_sb, PTR_ERR(handle)); + /* + * If we're going to skip the normal cleanup, we still need to + * make sure that the in-core orphan linked list is properly + * cleaned up. + */ + ext4_orphan_del(NULL, inode); + if (freeze_protected) + sb_end_intwrite(inode->i_sb); + goto no_delete; + } + + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + + /* + * Set inode->i_size to 0 before calling ext4_truncate(). We need + * special handling of symlinks here because i_size is used to + * determine whether ext4_inode_info->i_data contains symlink data or + * block mappings. Setting i_size to 0 will remove its fast symlink + * status. Erase i_data so that it becomes a valid empty block map. + */ + if (ext4_inode_is_fast_symlink(inode)) + memset(EXT4_I(inode)->i_data, 0, sizeof(EXT4_I(inode)->i_data)); + inode->i_size = 0; + err = ext4_mark_inode_dirty(handle, inode); + if (err) { + ext4_warning(inode->i_sb, + "couldn't mark inode dirty (err %d)", err); + goto stop_handle; + } + if (inode->i_blocks) { + err = ext4_truncate(inode); + if (err) { + ext4_error(inode->i_sb, + "couldn't truncate inode %lu (err %d)", + inode->i_ino, err); + goto stop_handle; + } + } + + /* Remove xattr references. */ + err = ext4_xattr_delete_inode(handle, inode, &ea_inode_array, + extra_credits); + if (err) { + ext4_warning(inode->i_sb, "xattr delete (err %d)", err); +stop_handle: + ext4_journal_stop(handle); + ext4_orphan_del(NULL, inode); + if (freeze_protected) + sb_end_intwrite(inode->i_sb); + ext4_xattr_inode_array_free(ea_inode_array); + goto no_delete; + } + + /* + * Kill off the orphan record which ext4_truncate created. + * AKPM: I think this can be inside the above `if'. + * Note that ext4_orphan_del() has to be able to cope with the + * deletion of a non-existent orphan - this is because we don't + * know if ext4_truncate() actually created an orphan record. + * (Well, we could do this if we need to, but heck - it works) + */ + ext4_orphan_del(handle, inode); + EXT4_I(inode)->i_dtime = (__u32)ktime_get_real_seconds(); + + /* + * One subtle ordering requirement: if anything has gone wrong + * (transaction abort, IO errors, whatever), then we can still + * do these next steps (the fs will already have been marked as + * having errors), but we can't free the inode if the mark_dirty + * fails. + */ + if (ext4_mark_inode_dirty(handle, inode)) + /* If that failed, just do the required in-core inode clear. */ + ext4_clear_inode(inode); + else + ext4_free_inode(handle, inode); + ext4_journal_stop(handle); + if (freeze_protected) + sb_end_intwrite(inode->i_sb); + ext4_xattr_inode_array_free(ea_inode_array); + return; +no_delete: + ext4_clear_inode(inode); /* We must guarantee clearing of inode... */ +} + +#ifdef CONFIG_QUOTA +qsize_t *ext4_get_reserved_space(struct inode *inode) +{ + return &EXT4_I(inode)->i_reserved_quota; +} +#endif + +/* + * Called with i_data_sem down, which is important since we can call + * ext4_discard_preallocations() from here. + */ +void ext4_da_update_reserve_space(struct inode *inode, + int used, int quota_claim) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct ext4_inode_info *ei = EXT4_I(inode); + + spin_lock(&ei->i_block_reservation_lock); + trace_ext4_da_update_reserve_space(inode, used, quota_claim); + if (unlikely(used > ei->i_reserved_data_blocks)) { + ext4_warning(inode->i_sb, "%s: ino %lu, used %d " + "with only %d reserved data blocks", + __func__, inode->i_ino, used, + ei->i_reserved_data_blocks); + WARN_ON(1); + used = ei->i_reserved_data_blocks; + } + + /* Update per-inode reservations */ + ei->i_reserved_data_blocks -= used; + percpu_counter_sub(&sbi->s_dirtyclusters_counter, used); + + spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + + /* Update quota subsystem for data blocks */ + if (quota_claim) + dquot_claim_block(inode, EXT4_C2B(sbi, used)); + else { + /* + * We did fallocate with an offset that is already delayed + * allocated. So on delayed allocated writeback we should + * not re-claim the quota for fallocated blocks. + */ + dquot_release_reservation_block(inode, EXT4_C2B(sbi, used)); + } + + /* + * If we have done all the pending block allocations and if + * there aren't any writers on the inode, we can discard the + * inode's preallocations. + */ + if ((ei->i_reserved_data_blocks == 0) && + (atomic_read(&inode->i_writecount) == 0)) + ext4_discard_preallocations(inode); +} + +static int __check_block_validity(struct inode *inode, const char *func, + unsigned int line, + struct ext4_map_blocks *map) +{ + if (ext4_has_feature_journal(inode->i_sb) && + (inode->i_ino == + le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_journal_inum))) + return 0; + if (!ext4_inode_block_valid(inode, map->m_pblk, map->m_len)) { + ext4_error_inode(inode, func, line, map->m_pblk, + "lblock %lu mapped to illegal pblock %llu " + "(length %d)", (unsigned long) map->m_lblk, + map->m_pblk, map->m_len); + return -EFSCORRUPTED; + } + return 0; +} + +int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk, + ext4_lblk_t len) +{ + int ret; + + if (ext4_encrypted_inode(inode)) + return fscrypt_zeroout_range(inode, lblk, pblk, len); + + ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS); + if (ret > 0) + ret = 0; + + return ret; +} + +#define check_block_validity(inode, map) \ + __check_block_validity((inode), __func__, __LINE__, (map)) + +#ifdef ES_AGGRESSIVE_TEST +static void ext4_map_blocks_es_recheck(handle_t *handle, + struct inode *inode, + struct ext4_map_blocks *es_map, + struct ext4_map_blocks *map, + int flags) +{ + int retval; + + map->m_flags = 0; + /* + * There is a race window that the result is not the same. + * e.g. xfstests #223 when dioread_nolock enables. The reason + * is that we lookup a block mapping in extent status tree with + * out taking i_data_sem. So at the time the unwritten extent + * could be converted. + */ + down_read(&EXT4_I(inode)->i_data_sem); + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + retval = ext4_ext_map_blocks(handle, inode, map, flags & + EXT4_GET_BLOCKS_KEEP_SIZE); + } else { + retval = ext4_ind_map_blocks(handle, inode, map, flags & + EXT4_GET_BLOCKS_KEEP_SIZE); + } + up_read((&EXT4_I(inode)->i_data_sem)); + + /* + * We don't check m_len because extent will be collpased in status + * tree. So the m_len might not equal. + */ + if (es_map->m_lblk != map->m_lblk || + es_map->m_flags != map->m_flags || + es_map->m_pblk != map->m_pblk) { + printk("ES cache assertion failed for inode: %lu " + "es_cached ex [%d/%d/%llu/%x] != " + "found ex [%d/%d/%llu/%x] retval %d flags %x\n", + inode->i_ino, es_map->m_lblk, es_map->m_len, + es_map->m_pblk, es_map->m_flags, map->m_lblk, + map->m_len, map->m_pblk, map->m_flags, + retval, flags); + } +} +#endif /* ES_AGGRESSIVE_TEST */ + +/* + * The ext4_map_blocks() function tries to look up the requested blocks, + * and returns if the blocks are already mapped. + * + * Otherwise it takes the write lock of the i_data_sem and allocate blocks + * and store the allocated blocks in the result buffer head and mark it + * mapped. + * + * If file type is extents based, it will call ext4_ext_map_blocks(), + * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping + * based files + * + * On success, it returns the number of blocks being mapped or allocated. if + * create==0 and the blocks are pre-allocated and unwritten, the resulting @map + * is marked as unwritten. If the create == 1, it will mark @map as mapped. + * + * It returns 0 if plain look up failed (blocks have not been allocated), in + * that case, @map is returned as unmapped but we still do fill map->m_len to + * indicate the length of a hole starting at map->m_lblk. + * + * It returns the error in case of allocation failure. + */ +int ext4_map_blocks(handle_t *handle, struct inode *inode, + struct ext4_map_blocks *map, int flags) +{ + struct extent_status es; + int retval; + int ret = 0; +#ifdef ES_AGGRESSIVE_TEST + struct ext4_map_blocks orig_map; + + memcpy(&orig_map, map, sizeof(*map)); +#endif + + map->m_flags = 0; + ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u," + "logical block %lu\n", inode->i_ino, flags, map->m_len, + (unsigned long) map->m_lblk); + + /* + * ext4_map_blocks returns an int, and m_len is an unsigned int + */ + if (unlikely(map->m_len > INT_MAX)) + map->m_len = INT_MAX; + + /* We can handle the block number less than EXT_MAX_BLOCKS */ + if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS)) + return -EFSCORRUPTED; + + /* Lookup extent status tree firstly */ + if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) { + if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) { + map->m_pblk = ext4_es_pblock(&es) + + map->m_lblk - es.es_lblk; + map->m_flags |= ext4_es_is_written(&es) ? + EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN; + retval = es.es_len - (map->m_lblk - es.es_lblk); + if (retval > map->m_len) + retval = map->m_len; + map->m_len = retval; + } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) { + map->m_pblk = 0; + retval = es.es_len - (map->m_lblk - es.es_lblk); + if (retval > map->m_len) + retval = map->m_len; + map->m_len = retval; + retval = 0; + } else { + BUG_ON(1); + } +#ifdef ES_AGGRESSIVE_TEST + ext4_map_blocks_es_recheck(handle, inode, map, + &orig_map, flags); +#endif + goto found; + } + + /* + * Try to see if we can get the block without requesting a new + * file system block. + */ + down_read(&EXT4_I(inode)->i_data_sem); + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + retval = ext4_ext_map_blocks(handle, inode, map, flags & + EXT4_GET_BLOCKS_KEEP_SIZE); + } else { + retval = ext4_ind_map_blocks(handle, inode, map, flags & + EXT4_GET_BLOCKS_KEEP_SIZE); + } + if (retval > 0) { + unsigned int status; + + if (unlikely(retval != map->m_len)) { + ext4_warning(inode->i_sb, + "ES len assertion failed for inode " + "%lu: retval %d != map->m_len %d", + inode->i_ino, retval, map->m_len); + WARN_ON(1); + } + + status = map->m_flags & EXT4_MAP_UNWRITTEN ? + EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; + if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && + !(status & EXTENT_STATUS_WRITTEN) && + ext4_find_delalloc_range(inode, map->m_lblk, + map->m_lblk + map->m_len - 1)) + status |= EXTENT_STATUS_DELAYED; + ret = ext4_es_insert_extent(inode, map->m_lblk, + map->m_len, map->m_pblk, status); + if (ret < 0) + retval = ret; + } + up_read((&EXT4_I(inode)->i_data_sem)); + +found: + if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { + ret = check_block_validity(inode, map); + if (ret != 0) + return ret; + } + + /* If it is only a block(s) look up */ + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) + return retval; + + /* + * Returns if the blocks have already allocated + * + * Note that if blocks have been preallocated + * ext4_ext_get_block() returns the create = 0 + * with buffer head unmapped. + */ + if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) + /* + * If we need to convert extent to unwritten + * we continue and do the actual work in + * ext4_ext_map_blocks() + */ + if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) + return retval; + + /* + * Here we clear m_flags because after allocating an new extent, + * it will be set again. + */ + map->m_flags &= ~EXT4_MAP_FLAGS; + + /* + * New blocks allocate and/or writing to unwritten extent + * will possibly result in updating i_data, so we take + * the write lock of i_data_sem, and call get_block() + * with create == 1 flag. + */ + down_write(&EXT4_I(inode)->i_data_sem); + + /* + * We need to check for EXT4 here because migrate + * could have changed the inode type in between + */ + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { + retval = ext4_ext_map_blocks(handle, inode, map, flags); + } else { + retval = ext4_ind_map_blocks(handle, inode, map, flags); + + if (retval > 0 && map->m_flags & EXT4_MAP_NEW) { + /* + * We allocated new blocks which will result in + * i_data's format changing. Force the migrate + * to fail by clearing migrate flags + */ + ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE); + } + + /* + * Update reserved blocks/metadata blocks after successful + * block allocation which had been deferred till now. We don't + * support fallocate for non extent files. So we can update + * reserve space here. + */ + if ((retval > 0) && + (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)) + ext4_da_update_reserve_space(inode, retval, 1); + } + + if (retval > 0) { + unsigned int status; + + if (unlikely(retval != map->m_len)) { + ext4_warning(inode->i_sb, + "ES len assertion failed for inode " + "%lu: retval %d != map->m_len %d", + inode->i_ino, retval, map->m_len); + WARN_ON(1); + } + + /* + * We have to zeroout blocks before inserting them into extent + * status tree. Otherwise someone could look them up there and + * use them before they are really zeroed. We also have to + * unmap metadata before zeroing as otherwise writeback can + * overwrite zeros with stale data from block device. + */ + if (flags & EXT4_GET_BLOCKS_ZERO && + map->m_flags & EXT4_MAP_MAPPED && + map->m_flags & EXT4_MAP_NEW) { + clean_bdev_aliases(inode->i_sb->s_bdev, map->m_pblk, + map->m_len); + ret = ext4_issue_zeroout(inode, map->m_lblk, + map->m_pblk, map->m_len); + if (ret) { + retval = ret; + goto out_sem; + } + } + + /* + * If the extent has been zeroed out, we don't need to update + * extent status tree. + */ + if ((flags & EXT4_GET_BLOCKS_PRE_IO) && + ext4_es_lookup_extent(inode, map->m_lblk, &es)) { + if (ext4_es_is_written(&es)) + goto out_sem; + } + status = map->m_flags & EXT4_MAP_UNWRITTEN ? + EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; + if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && + !(status & EXTENT_STATUS_WRITTEN) && + ext4_find_delalloc_range(inode, map->m_lblk, + map->m_lblk + map->m_len - 1)) + status |= EXTENT_STATUS_DELAYED; + ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, + map->m_pblk, status); + if (ret < 0) { + retval = ret; + goto out_sem; + } + } + +out_sem: + up_write((&EXT4_I(inode)->i_data_sem)); + if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { + ret = check_block_validity(inode, map); + if (ret != 0) + return ret; + + /* + * Inodes with freshly allocated blocks where contents will be + * visible after transaction commit must be on transaction's + * ordered data list. + */ + if (map->m_flags & EXT4_MAP_NEW && + !(map->m_flags & EXT4_MAP_UNWRITTEN) && + !(flags & EXT4_GET_BLOCKS_ZERO) && + !ext4_is_quota_file(inode) && + ext4_should_order_data(inode)) { + loff_t start_byte = + (loff_t)map->m_lblk << inode->i_blkbits; + loff_t length = (loff_t)map->m_len << inode->i_blkbits; + + if (flags & EXT4_GET_BLOCKS_IO_SUBMIT) + ret = ext4_jbd2_inode_add_wait(handle, inode, + start_byte, length); + else + ret = ext4_jbd2_inode_add_write(handle, inode, + start_byte, length); + if (ret) + return ret; + } + } + return retval; +} + +/* + * Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages + * we have to be careful as someone else may be manipulating b_state as well. + */ +static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags) +{ + unsigned long old_state; + unsigned long new_state; + + flags &= EXT4_MAP_FLAGS; + + /* Dummy buffer_head? Set non-atomically. */ + if (!bh->b_page) { + bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags; + return; + } + /* + * Someone else may be modifying b_state. Be careful! This is ugly but + * once we get rid of using bh as a container for mapping information + * to pass to / from get_block functions, this can go away. + */ + do { + old_state = READ_ONCE(bh->b_state); + new_state = (old_state & ~EXT4_MAP_FLAGS) | flags; + } while (unlikely( + cmpxchg(&bh->b_state, old_state, new_state) != old_state)); +} + +static int _ext4_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int flags) +{ + struct ext4_map_blocks map; + int ret = 0; + + if (ext4_has_inline_data(inode)) + return -ERANGE; + + map.m_lblk = iblock; + map.m_len = bh->b_size >> inode->i_blkbits; + + ret = ext4_map_blocks(ext4_journal_current_handle(), inode, &map, + flags); + if (ret > 0) { + map_bh(bh, inode->i_sb, map.m_pblk); + ext4_update_bh_state(bh, map.m_flags); + bh->b_size = inode->i_sb->s_blocksize * map.m_len; + ret = 0; + } else if (ret == 0) { + /* hole case, need to fill in bh->b_size */ + bh->b_size = inode->i_sb->s_blocksize * map.m_len; + } + return ret; +} + +int ext4_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int create) +{ + return _ext4_get_block(inode, iblock, bh, + create ? EXT4_GET_BLOCKS_CREATE : 0); +} + +/* + * Get block function used when preparing for buffered write if we require + * creating an unwritten extent if blocks haven't been allocated. The extent + * will be converted to written after the IO is complete. + */ +int ext4_get_block_unwritten(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n", + inode->i_ino, create); + return _ext4_get_block(inode, iblock, bh_result, + EXT4_GET_BLOCKS_IO_CREATE_EXT); +} + +/* Maximum number of blocks we map for direct IO at once. */ +#define DIO_MAX_BLOCKS 4096 + +/* + * Get blocks function for the cases that need to start a transaction - + * generally difference cases of direct IO and DAX IO. It also handles retries + * in case of ENOSPC. + */ +static int ext4_get_block_trans(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int flags) +{ + int dio_credits; + handle_t *handle; + int retries = 0; + int ret; + + /* Trim mapping request to maximum we can map at once for DIO */ + if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS) + bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits; + dio_credits = ext4_chunk_trans_blocks(inode, + bh_result->b_size >> inode->i_blkbits); +retry: + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + ret = _ext4_get_block(inode, iblock, bh_result, flags); + ext4_journal_stop(handle); + + if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry; + return ret; +} + +/* Get block function for DIO reads and writes to inodes without extents */ +int ext4_dio_get_block(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int create) +{ + /* We don't expect handle for direct IO */ + WARN_ON_ONCE(ext4_journal_current_handle()); + + if (!create) + return _ext4_get_block(inode, iblock, bh, 0); + return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE); +} + +/* + * Get block function for AIO DIO writes when we create unwritten extent if + * blocks are not allocated yet. The extent will be converted to written + * after IO is complete. + */ +static int ext4_dio_get_block_unwritten_async(struct inode *inode, + sector_t iblock, struct buffer_head *bh_result, int create) +{ + int ret; + + /* We don't expect handle for direct IO */ + WARN_ON_ONCE(ext4_journal_current_handle()); + + ret = ext4_get_block_trans(inode, iblock, bh_result, + EXT4_GET_BLOCKS_IO_CREATE_EXT); + + /* + * When doing DIO using unwritten extents, we need io_end to convert + * unwritten extents to written on IO completion. We allocate io_end + * once we spot unwritten extent and store it in b_private. Generic + * DIO code keeps b_private set and furthermore passes the value to + * our completion callback in 'private' argument. + */ + if (!ret && buffer_unwritten(bh_result)) { + if (!bh_result->b_private) { + ext4_io_end_t *io_end; + + io_end = ext4_init_io_end(inode, GFP_KERNEL); + if (!io_end) + return -ENOMEM; + bh_result->b_private = io_end; + ext4_set_io_unwritten_flag(inode, io_end); + } + set_buffer_defer_completion(bh_result); + } + + return ret; +} + +/* + * Get block function for non-AIO DIO writes when we create unwritten extent if + * blocks are not allocated yet. The extent will be converted to written + * after IO is complete by ext4_direct_IO_write(). + */ +static int ext4_dio_get_block_unwritten_sync(struct inode *inode, + sector_t iblock, struct buffer_head *bh_result, int create) +{ + int ret; + + /* We don't expect handle for direct IO */ + WARN_ON_ONCE(ext4_journal_current_handle()); + + ret = ext4_get_block_trans(inode, iblock, bh_result, + EXT4_GET_BLOCKS_IO_CREATE_EXT); + + /* + * Mark inode as having pending DIO writes to unwritten extents. + * ext4_direct_IO_write() checks this flag and converts extents to + * written. + */ + if (!ret && buffer_unwritten(bh_result)) + ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); + + return ret; +} + +static int ext4_dio_get_block_overwrite(struct inode *inode, sector_t iblock, + struct buffer_head *bh_result, int create) +{ + int ret; + + ext4_debug("ext4_dio_get_block_overwrite: inode %lu, create flag %d\n", + inode->i_ino, create); + /* We don't expect handle for direct IO */ + WARN_ON_ONCE(ext4_journal_current_handle()); + + ret = _ext4_get_block(inode, iblock, bh_result, 0); + /* + * Blocks should have been preallocated! ext4_file_write_iter() checks + * that. + */ + WARN_ON_ONCE(!buffer_mapped(bh_result) || buffer_unwritten(bh_result)); + + return ret; +} + + +/* + * `handle' can be NULL if create is zero + */ +struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, + ext4_lblk_t block, int map_flags) +{ + struct ext4_map_blocks map; + struct buffer_head *bh; + int create = map_flags & EXT4_GET_BLOCKS_CREATE; + int err; + + J_ASSERT(handle != NULL || create == 0); + + map.m_lblk = block; + map.m_len = 1; + err = ext4_map_blocks(handle, inode, &map, map_flags); + + if (err == 0) + return create ? ERR_PTR(-ENOSPC) : NULL; + if (err < 0) + return ERR_PTR(err); + + bh = sb_getblk(inode->i_sb, map.m_pblk); + if (unlikely(!bh)) + return ERR_PTR(-ENOMEM); + if (map.m_flags & EXT4_MAP_NEW) { + J_ASSERT(create != 0); + J_ASSERT(handle != NULL); + + /* + * Now that we do not always journal data, we should + * keep in mind whether this should always journal the + * new buffer as metadata. For now, regular file + * writes use ext4_get_block instead, so it's not a + * problem. + */ + lock_buffer(bh); + BUFFER_TRACE(bh, "call get_create_access"); + err = ext4_journal_get_create_access(handle, bh); + if (unlikely(err)) { + unlock_buffer(bh); + goto errout; + } + if (!buffer_uptodate(bh)) { + memset(bh->b_data, 0, inode->i_sb->s_blocksize); + set_buffer_uptodate(bh); + } + unlock_buffer(bh); + BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, inode, bh); + if (unlikely(err)) + goto errout; + } else + BUFFER_TRACE(bh, "not a new buffer"); + return bh; +errout: + brelse(bh); + return ERR_PTR(err); +} + +struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, + ext4_lblk_t block, int map_flags) +{ + struct buffer_head *bh; + + bh = ext4_getblk(handle, inode, block, map_flags); + if (IS_ERR(bh)) + return bh; + if (!bh || buffer_uptodate(bh)) + return bh; + ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh); + wait_on_buffer(bh); + if (buffer_uptodate(bh)) + return bh; + put_bh(bh); + return ERR_PTR(-EIO); +} + +/* Read a contiguous batch of blocks. */ +int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count, + bool wait, struct buffer_head **bhs) +{ + int i, err; + + for (i = 0; i < bh_count; i++) { + bhs[i] = ext4_getblk(NULL, inode, block + i, 0 /* map_flags */); + if (IS_ERR(bhs[i])) { + err = PTR_ERR(bhs[i]); + bh_count = i; + goto out_brelse; + } + } + + for (i = 0; i < bh_count; i++) + /* Note that NULL bhs[i] is valid because of holes. */ + if (bhs[i] && !buffer_uptodate(bhs[i])) + ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, + &bhs[i]); + + if (!wait) + return 0; + + for (i = 0; i < bh_count; i++) + if (bhs[i]) + wait_on_buffer(bhs[i]); + + for (i = 0; i < bh_count; i++) { + if (bhs[i] && !buffer_uptodate(bhs[i])) { + err = -EIO; + goto out_brelse; + } + } + return 0; + +out_brelse: + for (i = 0; i < bh_count; i++) { + brelse(bhs[i]); + bhs[i] = NULL; + } + return err; +} + +int ext4_walk_page_buffers(handle_t *handle, + struct buffer_head *head, + unsigned from, + unsigned to, + int *partial, + int (*fn)(handle_t *handle, + struct buffer_head *bh)) +{ + struct buffer_head *bh; + unsigned block_start, block_end; + unsigned blocksize = head->b_size; + int err, ret = 0; + struct buffer_head *next; + + for (bh = head, block_start = 0; + ret == 0 && (bh != head || !block_start); + block_start = block_end, bh = next) { + next = bh->b_this_page; + block_end = block_start + blocksize; + if (block_end <= from || block_start >= to) { + if (partial && !buffer_uptodate(bh)) + *partial = 1; + continue; + } + err = (*fn)(handle, bh); + if (!ret) + ret = err; + } + return ret; +} + +/* + * To preserve ordering, it is essential that the hole instantiation and + * the data write be encapsulated in a single transaction. We cannot + * close off a transaction and start a new one between the ext4_get_block() + * and the commit_write(). So doing the jbd2_journal_start at the start of + * prepare_write() is the right place. + * + * Also, this function can nest inside ext4_writepage(). In that case, we + * *know* that ext4_writepage() has generated enough buffer credits to do the + * whole page. So we won't block on the journal in that case, which is good, + * because the caller may be PF_MEMALLOC. + * + * By accident, ext4 can be reentered when a transaction is open via + * quota file writes. If we were to commit the transaction while thus + * reentered, there can be a deadlock - we would be holding a quota + * lock, and the commit would never complete if another thread had a + * transaction open and was blocking on the quota lock - a ranking + * violation. + * + * So what we do is to rely on the fact that jbd2_journal_stop/journal_start + * will _not_ run commit under these circumstances because handle->h_ref + * is elevated. We'll still have enough credits for the tiny quotafile + * write. + */ +int do_journal_get_write_access(handle_t *handle, + struct buffer_head *bh) +{ + int dirty = buffer_dirty(bh); + int ret; + + if (!buffer_mapped(bh) || buffer_freed(bh)) + return 0; + /* + * __block_write_begin() could have dirtied some buffers. Clean + * the dirty bit as jbd2_journal_get_write_access() could complain + * otherwise about fs integrity issues. Setting of the dirty bit + * by __block_write_begin() isn't a real problem here as we clear + * the bit before releasing a page lock and thus writeback cannot + * ever write the buffer. + */ + if (dirty) + clear_buffer_dirty(bh); + BUFFER_TRACE(bh, "get write access"); + ret = ext4_journal_get_write_access(handle, bh); + if (!ret && dirty) + ret = ext4_handle_dirty_metadata(handle, NULL, bh); + return ret; +} + +#ifdef CONFIG_EXT4_FS_ENCRYPTION +static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, + get_block_t *get_block) +{ + unsigned from = pos & (PAGE_SIZE - 1); + unsigned to = from + len; + struct inode *inode = page->mapping->host; + unsigned block_start, block_end; + sector_t block; + int err = 0; + unsigned blocksize = inode->i_sb->s_blocksize; + unsigned bbits; + struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; + bool decrypt = false; + + BUG_ON(!PageLocked(page)); + BUG_ON(from > PAGE_SIZE); + BUG_ON(to > PAGE_SIZE); + BUG_ON(from > to); + + if (!page_has_buffers(page)) + create_empty_buffers(page, blocksize, 0); + head = page_buffers(page); + bbits = ilog2(blocksize); + block = (sector_t)page->index << (PAGE_SHIFT - bbits); + + for (bh = head, block_start = 0; bh != head || !block_start; + block++, block_start = block_end, bh = bh->b_this_page) { + block_end = block_start + blocksize; + if (block_end <= from || block_start >= to) { + if (PageUptodate(page)) { + if (!buffer_uptodate(bh)) + set_buffer_uptodate(bh); + } + continue; + } + if (buffer_new(bh)) + clear_buffer_new(bh); + if (!buffer_mapped(bh)) { + WARN_ON(bh->b_size != blocksize); + err = get_block(inode, block, bh, 1); + if (err) + break; + if (buffer_new(bh)) { + clean_bdev_bh_alias(bh); + if (PageUptodate(page)) { + clear_buffer_new(bh); + set_buffer_uptodate(bh); + mark_buffer_dirty(bh); + continue; + } + if (block_end > to || block_start < from) + zero_user_segments(page, to, block_end, + block_start, from); + continue; + } + } + if (PageUptodate(page)) { + if (!buffer_uptodate(bh)) + set_buffer_uptodate(bh); + continue; + } + if (!buffer_uptodate(bh) && !buffer_delay(bh) && + !buffer_unwritten(bh) && + (block_start < from || block_end > to)) { + ll_rw_block(REQ_OP_READ, 0, 1, &bh); + *wait_bh++ = bh; + decrypt = ext4_encrypted_inode(inode) && + S_ISREG(inode->i_mode); + } + } + /* + * If we issued read requests, let them complete. + */ + while (wait_bh > wait) { + wait_on_buffer(*--wait_bh); + if (!buffer_uptodate(*wait_bh)) + err = -EIO; + } + if (unlikely(err)) + page_zero_new_buffers(page, from, to); + else if (decrypt) + err = fscrypt_decrypt_page(page->mapping->host, page, + PAGE_SIZE, 0, page->index); + return err; +} +#endif + +static int ext4_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) +{ + struct inode *inode = mapping->host; + int ret, needed_blocks; + handle_t *handle; + int retries = 0; + struct page *page; + pgoff_t index; + unsigned from, to; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + trace_ext4_write_begin(inode, pos, len, flags); + /* + * Reserve one block more for addition to orphan list in case + * we allocate blocks but write fails for some reason + */ + needed_blocks = ext4_writepage_trans_blocks(inode) + 1; + index = pos >> PAGE_SHIFT; + from = pos & (PAGE_SIZE - 1); + to = from + len; + + if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { + ret = ext4_try_to_write_inline_data(mapping, inode, pos, len, + flags, pagep); + if (ret < 0) + return ret; + if (ret == 1) + return 0; + } + + /* + * grab_cache_page_write_begin() can take a long time if the + * system is thrashing due to memory pressure, or if the page + * is being written back. So grab it first before we start + * the transaction handle. This also allows us to allocate + * the page (if needed) without using GFP_NOFS. + */ +retry_grab: + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; + unlock_page(page); + +retry_journal: + handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks); + if (IS_ERR(handle)) { + put_page(page); + return PTR_ERR(handle); + } + + lock_page(page); + if (page->mapping != mapping) { + /* The page got truncated from under us */ + unlock_page(page); + put_page(page); + ext4_journal_stop(handle); + goto retry_grab; + } + /* In case writeback began while the page was unlocked */ + wait_for_stable_page(page); + +#ifdef CONFIG_EXT4_FS_ENCRYPTION + if (ext4_should_dioread_nolock(inode)) + ret = ext4_block_write_begin(page, pos, len, + ext4_get_block_unwritten); + else + ret = ext4_block_write_begin(page, pos, len, + ext4_get_block); +#else + if (ext4_should_dioread_nolock(inode)) + ret = __block_write_begin(page, pos, len, + ext4_get_block_unwritten); + else + ret = __block_write_begin(page, pos, len, ext4_get_block); +#endif + if (!ret && ext4_should_journal_data(inode)) { + ret = ext4_walk_page_buffers(handle, page_buffers(page), + from, to, NULL, + do_journal_get_write_access); + } + + if (ret) { + unlock_page(page); + /* + * __block_write_begin may have instantiated a few blocks + * outside i_size. Trim these off again. Don't need + * i_size_read because we hold i_mutex. + * + * Add inode to orphan list in case we crash before + * truncate finishes + */ + if (pos + len > inode->i_size && ext4_can_truncate(inode)) + ext4_orphan_add(handle, inode); + + ext4_journal_stop(handle); + if (pos + len > inode->i_size) { + ext4_truncate_failed_write(inode); + /* + * If truncate failed early the inode might + * still be on the orphan list; we need to + * make sure the inode is removed from the + * orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } + + if (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry_journal; + put_page(page); + return ret; + } + *pagep = page; + return ret; +} + +/* For write_end() in data=journal mode */ +static int write_end_fn(handle_t *handle, struct buffer_head *bh) +{ + int ret; + if (!buffer_mapped(bh) || buffer_freed(bh)) + return 0; + set_buffer_uptodate(bh); + ret = ext4_handle_dirty_metadata(handle, NULL, bh); + clear_buffer_meta(bh); + clear_buffer_prio(bh); + return ret; +} + +/* + * We need to pick up the new inode size which generic_commit_write gave us + * `file' can be NULL - eg, when called from page_symlink(). + * + * ext4 never places buffers on inode->i_mapping->private_list. metadata + * buffers are managed internally. + */ +static int ext4_write_end(struct file *file, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + handle_t *handle = ext4_journal_current_handle(); + struct inode *inode = mapping->host; + loff_t old_size = inode->i_size; + int ret = 0, ret2; + int i_size_changed = 0; + int inline_data = ext4_has_inline_data(inode); + + trace_ext4_write_end(inode, pos, len, copied); + if (inline_data) { + ret = ext4_write_inline_data_end(inode, pos, len, + copied, page); + if (ret < 0) { + unlock_page(page); + put_page(page); + goto errout; + } + copied = ret; + } else + copied = block_write_end(file, mapping, pos, + len, copied, page, fsdata); + /* + * it's important to update i_size while still holding page lock: + * page writeout could otherwise come in and zero beyond i_size. + */ + i_size_changed = ext4_update_inode_size(inode, pos + copied); + unlock_page(page); + put_page(page); + + if (old_size < pos) + pagecache_isize_extended(inode, old_size, pos); + /* + * Don't mark the inode dirty under page lock. First, it unnecessarily + * makes the holding time of page lock longer. Second, it forces lock + * ordering of page lock and transaction start for journaling + * filesystems. + */ + if (i_size_changed || inline_data) + ext4_mark_inode_dirty(handle, inode); + + if (pos + len > inode->i_size && ext4_can_truncate(inode)) + /* if we have allocated more blocks and copied + * less. We will have blocks allocated outside + * inode->i_size. So truncate them + */ + ext4_orphan_add(handle, inode); +errout: + ret2 = ext4_journal_stop(handle); + if (!ret) + ret = ret2; + + if (pos + len > inode->i_size) { + ext4_truncate_failed_write(inode); + /* + * If truncate failed early the inode might still be + * on the orphan list; we need to make sure the inode + * is removed from the orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } + + return ret ? ret : copied; +} + +/* + * This is a private version of page_zero_new_buffers() which doesn't + * set the buffer to be dirty, since in data=journalled mode we need + * to call ext4_handle_dirty_metadata() instead. + */ +static void ext4_journalled_zero_new_buffers(handle_t *handle, + struct page *page, + unsigned from, unsigned to) +{ + unsigned int block_start = 0, block_end; + struct buffer_head *head, *bh; + + bh = head = page_buffers(page); + do { + block_end = block_start + bh->b_size; + if (buffer_new(bh)) { + if (block_end > from && block_start < to) { + if (!PageUptodate(page)) { + unsigned start, size; + + start = max(from, block_start); + size = min(to, block_end) - start; + + zero_user(page, start, size); + write_end_fn(handle, bh); + } + clear_buffer_new(bh); + } + } + block_start = block_end; + bh = bh->b_this_page; + } while (bh != head); +} + +static int ext4_journalled_write_end(struct file *file, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + handle_t *handle = ext4_journal_current_handle(); + struct inode *inode = mapping->host; + loff_t old_size = inode->i_size; + int ret = 0, ret2; + int partial = 0; + unsigned from, to; + int size_changed = 0; + int inline_data = ext4_has_inline_data(inode); + + trace_ext4_journalled_write_end(inode, pos, len, copied); + from = pos & (PAGE_SIZE - 1); + to = from + len; + + BUG_ON(!ext4_handle_valid(handle)); + + if (inline_data) { + ret = ext4_write_inline_data_end(inode, pos, len, + copied, page); + if (ret < 0) { + unlock_page(page); + put_page(page); + goto errout; + } + copied = ret; + } else if (unlikely(copied < len) && !PageUptodate(page)) { + copied = 0; + ext4_journalled_zero_new_buffers(handle, page, from, to); + } else { + if (unlikely(copied < len)) + ext4_journalled_zero_new_buffers(handle, page, + from + copied, to); + ret = ext4_walk_page_buffers(handle, page_buffers(page), from, + from + copied, &partial, + write_end_fn); + if (!partial) + SetPageUptodate(page); + } + size_changed = ext4_update_inode_size(inode, pos + copied); + ext4_set_inode_state(inode, EXT4_STATE_JDATA); + EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid; + unlock_page(page); + put_page(page); + + if (old_size < pos) + pagecache_isize_extended(inode, old_size, pos); + + if (size_changed || inline_data) { + ret2 = ext4_mark_inode_dirty(handle, inode); + if (!ret) + ret = ret2; + } + + if (pos + len > inode->i_size && ext4_can_truncate(inode)) + /* if we have allocated more blocks and copied + * less. We will have blocks allocated outside + * inode->i_size. So truncate them + */ + ext4_orphan_add(handle, inode); + +errout: + ret2 = ext4_journal_stop(handle); + if (!ret) + ret = ret2; + if (pos + len > inode->i_size) { + ext4_truncate_failed_write(inode); + /* + * If truncate failed early the inode might still be + * on the orphan list; we need to make sure the inode + * is removed from the orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } + + return ret ? ret : copied; +} + +/* + * Reserve space for a single cluster + */ +static int ext4_da_reserve_space(struct inode *inode) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct ext4_inode_info *ei = EXT4_I(inode); + int ret; + + /* + * We will charge metadata quota at writeout time; this saves + * us from metadata over-estimation, though we may go over by + * a small amount in the end. Here we just reserve for data. + */ + ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1)); + if (ret) + return ret; + + spin_lock(&ei->i_block_reservation_lock); + if (ext4_claim_free_clusters(sbi, 1, 0)) { + spin_unlock(&ei->i_block_reservation_lock); + dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1)); + return -ENOSPC; + } + ei->i_reserved_data_blocks++; + trace_ext4_da_reserve_space(inode); + spin_unlock(&ei->i_block_reservation_lock); + + return 0; /* success */ +} + +static void ext4_da_release_space(struct inode *inode, int to_free) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct ext4_inode_info *ei = EXT4_I(inode); + + if (!to_free) + return; /* Nothing to release, exit */ + + spin_lock(&EXT4_I(inode)->i_block_reservation_lock); + + trace_ext4_da_release_space(inode, to_free); + if (unlikely(to_free > ei->i_reserved_data_blocks)) { + /* + * if there aren't enough reserved blocks, then the + * counter is messed up somewhere. Since this + * function is called from invalidate page, it's + * harmless to return without any action. + */ + ext4_warning(inode->i_sb, "ext4_da_release_space: " + "ino %lu, to_free %d with only %d reserved " + "data blocks", inode->i_ino, to_free, + ei->i_reserved_data_blocks); + WARN_ON(1); + to_free = ei->i_reserved_data_blocks; + } + ei->i_reserved_data_blocks -= to_free; + + /* update fs dirty data blocks counter */ + percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free); + + spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); + + dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free)); +} + +static void ext4_da_page_release_reservation(struct page *page, + unsigned int offset, + unsigned int length) +{ + int to_release = 0, contiguous_blks = 0; + struct buffer_head *head, *bh; + unsigned int curr_off = 0; + struct inode *inode = page->mapping->host; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + unsigned int stop = offset + length; + int num_clusters; + ext4_fsblk_t lblk; + + BUG_ON(stop > PAGE_SIZE || stop < length); + + head = page_buffers(page); + bh = head; + do { + unsigned int next_off = curr_off + bh->b_size; + + if (next_off > stop) + break; + + if ((offset <= curr_off) && (buffer_delay(bh))) { + to_release++; + contiguous_blks++; + clear_buffer_delay(bh); + } else if (contiguous_blks) { + lblk = page->index << + (PAGE_SHIFT - inode->i_blkbits); + lblk += (curr_off >> inode->i_blkbits) - + contiguous_blks; + ext4_es_remove_extent(inode, lblk, contiguous_blks); + contiguous_blks = 0; + } + curr_off = next_off; + } while ((bh = bh->b_this_page) != head); + + if (contiguous_blks) { + lblk = page->index << (PAGE_SHIFT - inode->i_blkbits); + lblk += (curr_off >> inode->i_blkbits) - contiguous_blks; + ext4_es_remove_extent(inode, lblk, contiguous_blks); + } + + /* If we have released all the blocks belonging to a cluster, then we + * need to release the reserved space for that cluster. */ + num_clusters = EXT4_NUM_B2C(sbi, to_release); + while (num_clusters > 0) { + lblk = (page->index << (PAGE_SHIFT - inode->i_blkbits)) + + ((num_clusters - 1) << sbi->s_cluster_bits); + if (sbi->s_cluster_ratio == 1 || + !ext4_find_delalloc_cluster(inode, lblk)) + ext4_da_release_space(inode, 1); + + num_clusters--; + } +} + +/* + * Delayed allocation stuff + */ + +struct mpage_da_data { + struct inode *inode; + struct writeback_control *wbc; + + pgoff_t first_page; /* The first page to write */ + pgoff_t next_page; /* Current page to examine */ + pgoff_t last_page; /* Last page to examine */ + /* + * Extent to map - this can be after first_page because that can be + * fully mapped. We somewhat abuse m_flags to store whether the extent + * is delalloc or unwritten. + */ + struct ext4_map_blocks map; + struct ext4_io_submit io_submit; /* IO submission data */ + unsigned int do_map:1; +}; + +static void mpage_release_unused_pages(struct mpage_da_data *mpd, + bool invalidate) +{ + int nr_pages, i; + pgoff_t index, end; + struct pagevec pvec; + struct inode *inode = mpd->inode; + struct address_space *mapping = inode->i_mapping; + + /* This is necessary when next_page == 0. */ + if (mpd->first_page >= mpd->next_page) + return; + + index = mpd->first_page; + end = mpd->next_page - 1; + if (invalidate) { + ext4_lblk_t start, last; + start = index << (PAGE_SHIFT - inode->i_blkbits); + last = end << (PAGE_SHIFT - inode->i_blkbits); + ext4_es_remove_extent(inode, start, last - start + 1); + } + + pagevec_init(&pvec); + while (index <= end) { + nr_pages = pagevec_lookup_range(&pvec, mapping, &index, end); + if (nr_pages == 0) + break; + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + + BUG_ON(!PageLocked(page)); + BUG_ON(PageWriteback(page)); + if (invalidate) { + if (page_mapped(page)) + clear_page_dirty_for_io(page); + block_invalidatepage(page, 0, PAGE_SIZE); + ClearPageUptodate(page); + } + unlock_page(page); + } + pagevec_release(&pvec); + } +} + +static void ext4_print_free_blocks(struct inode *inode) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct super_block *sb = inode->i_sb; + struct ext4_inode_info *ei = EXT4_I(inode); + + ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld", + EXT4_C2B(EXT4_SB(inode->i_sb), + ext4_count_free_clusters(sb))); + ext4_msg(sb, KERN_CRIT, "Free/Dirty block details"); + ext4_msg(sb, KERN_CRIT, "free_blocks=%lld", + (long long) EXT4_C2B(EXT4_SB(sb), + percpu_counter_sum(&sbi->s_freeclusters_counter))); + ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld", + (long long) EXT4_C2B(EXT4_SB(sb), + percpu_counter_sum(&sbi->s_dirtyclusters_counter))); + ext4_msg(sb, KERN_CRIT, "Block reservation details"); + ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u", + ei->i_reserved_data_blocks); + return; +} + +static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh) +{ + return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh); +} + +/* + * This function is grabs code from the very beginning of + * ext4_map_blocks, but assumes that the caller is from delayed write + * time. This function looks up the requested blocks and sets the + * buffer delay bit under the protection of i_data_sem. + */ +static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, + struct ext4_map_blocks *map, + struct buffer_head *bh) +{ + struct extent_status es; + int retval; + sector_t invalid_block = ~((sector_t) 0xffff); +#ifdef ES_AGGRESSIVE_TEST + struct ext4_map_blocks orig_map; + + memcpy(&orig_map, map, sizeof(*map)); +#endif + + if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es)) + invalid_block = ~0; + + map->m_flags = 0; + ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u," + "logical block %lu\n", inode->i_ino, map->m_len, + (unsigned long) map->m_lblk); + + /* Lookup extent status tree firstly */ + if (ext4_es_lookup_extent(inode, iblock, &es)) { + if (ext4_es_is_hole(&es)) { + retval = 0; + down_read(&EXT4_I(inode)->i_data_sem); + goto add_delayed; + } + + /* + * Delayed extent could be allocated by fallocate. + * So we need to check it. + */ + if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) { + map_bh(bh, inode->i_sb, invalid_block); + set_buffer_new(bh); + set_buffer_delay(bh); + return 0; + } + + map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk; + retval = es.es_len - (iblock - es.es_lblk); + if (retval > map->m_len) + retval = map->m_len; + map->m_len = retval; + if (ext4_es_is_written(&es)) + map->m_flags |= EXT4_MAP_MAPPED; + else if (ext4_es_is_unwritten(&es)) + map->m_flags |= EXT4_MAP_UNWRITTEN; + else + BUG_ON(1); + +#ifdef ES_AGGRESSIVE_TEST + ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0); +#endif + return retval; + } + + /* + * Try to see if we can get the block without requesting a new + * file system block. + */ + down_read(&EXT4_I(inode)->i_data_sem); + if (ext4_has_inline_data(inode)) + retval = 0; + else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + retval = ext4_ext_map_blocks(NULL, inode, map, 0); + else + retval = ext4_ind_map_blocks(NULL, inode, map, 0); + +add_delayed: + if (retval == 0) { + int ret; + /* + * XXX: __block_prepare_write() unmaps passed block, + * is it OK? + */ + /* + * If the block was allocated from previously allocated cluster, + * then we don't need to reserve it again. However we still need + * to reserve metadata for every block we're going to write. + */ + if (EXT4_SB(inode->i_sb)->s_cluster_ratio == 1 || + !ext4_find_delalloc_cluster(inode, map->m_lblk)) { + ret = ext4_da_reserve_space(inode); + if (ret) { + /* not enough space to reserve */ + retval = ret; + goto out_unlock; + } + } + + ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, + ~0, EXTENT_STATUS_DELAYED); + if (ret) { + retval = ret; + goto out_unlock; + } + + map_bh(bh, inode->i_sb, invalid_block); + set_buffer_new(bh); + set_buffer_delay(bh); + } else if (retval > 0) { + int ret; + unsigned int status; + + if (unlikely(retval != map->m_len)) { + ext4_warning(inode->i_sb, + "ES len assertion failed for inode " + "%lu: retval %d != map->m_len %d", + inode->i_ino, retval, map->m_len); + WARN_ON(1); + } + + status = map->m_flags & EXT4_MAP_UNWRITTEN ? + EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; + ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, + map->m_pblk, status); + if (ret != 0) + retval = ret; + } + +out_unlock: + up_read((&EXT4_I(inode)->i_data_sem)); + + return retval; +} + +/* + * This is a special get_block_t callback which is used by + * ext4_da_write_begin(). It will either return mapped block or + * reserve space for a single block. + * + * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set. + * We also have b_blocknr = -1 and b_bdev initialized properly + * + * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set. + * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev + * initialized properly. + */ +int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, + struct buffer_head *bh, int create) +{ + struct ext4_map_blocks map; + int ret = 0; + + BUG_ON(create == 0); + BUG_ON(bh->b_size != inode->i_sb->s_blocksize); + + map.m_lblk = iblock; + map.m_len = 1; + + /* + * first, we need to know whether the block is allocated already + * preallocated blocks are unmapped but should treated + * the same as allocated blocks. + */ + ret = ext4_da_map_blocks(inode, iblock, &map, bh); + if (ret <= 0) + return ret; + + map_bh(bh, inode->i_sb, map.m_pblk); + ext4_update_bh_state(bh, map.m_flags); + + if (buffer_unwritten(bh)) { + /* A delayed write to unwritten bh should be marked + * new and mapped. Mapped ensures that we don't do + * get_block multiple times when we write to the same + * offset and new ensures that we do proper zero out + * for partial write. + */ + set_buffer_new(bh); + set_buffer_mapped(bh); + } + return 0; +} + +static int bget_one(handle_t *handle, struct buffer_head *bh) +{ + get_bh(bh); + return 0; +} + +static int bput_one(handle_t *handle, struct buffer_head *bh) +{ + put_bh(bh); + return 0; +} + +static int __ext4_journalled_writepage(struct page *page, + unsigned int len) +{ + struct address_space *mapping = page->mapping; + struct inode *inode = mapping->host; + struct buffer_head *page_bufs = NULL; + handle_t *handle = NULL; + int ret = 0, err = 0; + int inline_data = ext4_has_inline_data(inode); + struct buffer_head *inode_bh = NULL; + + ClearPageChecked(page); + + if (inline_data) { + BUG_ON(page->index != 0); + BUG_ON(len > ext4_get_max_inline_size(inode)); + inode_bh = ext4_journalled_write_inline_data(inode, len, page); + if (inode_bh == NULL) + goto out; + } else { + page_bufs = page_buffers(page); + if (!page_bufs) { + BUG(); + goto out; + } + ext4_walk_page_buffers(handle, page_bufs, 0, len, + NULL, bget_one); + } + /* + * We need to release the page lock before we start the + * journal, so grab a reference so the page won't disappear + * out from under us. + */ + get_page(page); + unlock_page(page); + + handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, + ext4_writepage_trans_blocks(inode)); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + put_page(page); + goto out_no_pagelock; + } + BUG_ON(!ext4_handle_valid(handle)); + + lock_page(page); + put_page(page); + if (page->mapping != mapping) { + /* The page got truncated from under us */ + ext4_journal_stop(handle); + ret = 0; + goto out; + } + + if (inline_data) { + ret = ext4_mark_inode_dirty(handle, inode); + } else { + ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, + do_journal_get_write_access); + + err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, + write_end_fn); + } + if (ret == 0) + ret = err; + EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid; + err = ext4_journal_stop(handle); + if (!ret) + ret = err; + + ext4_set_inode_state(inode, EXT4_STATE_JDATA); +out: + unlock_page(page); +out_no_pagelock: + if (!inline_data && page_bufs) + ext4_walk_page_buffers(NULL, page_bufs, 0, len, + NULL, bput_one); + brelse(inode_bh); + return ret; +} + +/* + * Note that we don't need to start a transaction unless we're journaling data + * because we should have holes filled from ext4_page_mkwrite(). We even don't + * need to file the inode to the transaction's list in ordered mode because if + * we are writing back data added by write(), the inode is already there and if + * we are writing back data modified via mmap(), no one guarantees in which + * transaction the data will hit the disk. In case we are journaling data, we + * cannot start transaction directly because transaction start ranks above page + * lock so we have to do some magic. + * + * This function can get called via... + * - ext4_writepages after taking page lock (have journal handle) + * - journal_submit_inode_data_buffers (no journal handle) + * - shrink_page_list via the kswapd/direct reclaim (no journal handle) + * - grab_page_cache when doing write_begin (have journal handle) + * + * We don't do any block allocation in this function. If we have page with + * multiple blocks we need to write those buffer_heads that are mapped. This + * is important for mmaped based write. So if we do with blocksize 1K + * truncate(f, 1024); + * a = mmap(f, 0, 4096); + * a[0] = 'a'; + * truncate(f, 4096); + * we have in the page first buffer_head mapped via page_mkwrite call back + * but other buffer_heads would be unmapped but dirty (dirty done via the + * do_wp_page). So writepage should write the first block. If we modify + * the mmap area beyond 1024 we will again get a page_fault and the + * page_mkwrite callback will do the block allocation and mark the + * buffer_heads mapped. + * + * We redirty the page if we have any buffer_heads that is either delay or + * unwritten in the page. + * + * We can get recursively called as show below. + * + * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> + * ext4_writepage() + * + * But since we don't do any block allocation we should not deadlock. + * Page also have the dirty flag cleared so we don't get recurive page_lock. + */ +static int ext4_writepage(struct page *page, + struct writeback_control *wbc) +{ + int ret = 0; + loff_t size; + unsigned int len; + struct buffer_head *page_bufs = NULL; + struct inode *inode = page->mapping->host; + struct ext4_io_submit io_submit; + bool keep_towrite = false; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) { + inode->i_mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE); + unlock_page(page); + return -EIO; + } + + trace_ext4_writepage(page); + size = i_size_read(inode); + if (page->index == size >> PAGE_SHIFT) + len = size & ~PAGE_MASK; + else + len = PAGE_SIZE; + + /* Should never happen but for bugs in other kernel subsystems */ + if (!page_has_buffers(page)) { + ext4_warning_inode(inode, + "page %lu does not have buffers attached", page->index); + ClearPageDirty(page); + unlock_page(page); + return 0; + } + + page_bufs = page_buffers(page); + /* + * We cannot do block allocation or other extent handling in this + * function. If there are buffers needing that, we have to redirty + * the page. But we may reach here when we do a journal commit via + * journal_submit_inode_data_buffers() and in that case we must write + * allocated buffers to achieve data=ordered mode guarantees. + * + * Also, if there is only one buffer per page (the fs block + * size == the page size), if one buffer needs block + * allocation or needs to modify the extent tree to clear the + * unwritten flag, we know that the page can't be written at + * all, so we might as well refuse the write immediately. + * Unfortunately if the block size != page size, we can't as + * easily detect this case using ext4_walk_page_buffers(), but + * for the extremely common case, this is an optimization that + * skips a useless round trip through ext4_bio_write_page(). + */ + if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL, + ext4_bh_delay_or_unwritten)) { + redirty_page_for_writepage(wbc, page); + if ((current->flags & PF_MEMALLOC) || + (inode->i_sb->s_blocksize == PAGE_SIZE)) { + /* + * For memory cleaning there's no point in writing only + * some buffers. So just bail out. Warn if we came here + * from direct reclaim. + */ + WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) + == PF_MEMALLOC); + unlock_page(page); + return 0; + } + keep_towrite = true; + } + + if (PageChecked(page) && ext4_should_journal_data(inode)) + /* + * It's mmapped pagecache. Add buffers and journal it. There + * doesn't seem much point in redirtying the page here. + */ + return __ext4_journalled_writepage(page, len); + + ext4_io_submit_init(&io_submit, wbc); + io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS); + if (!io_submit.io_end) { + redirty_page_for_writepage(wbc, page); + unlock_page(page); + return -ENOMEM; + } + ret = ext4_bio_write_page(&io_submit, page, len, wbc, keep_towrite); + ext4_io_submit(&io_submit); + /* Drop io_end reference we got from init */ + ext4_put_io_end_defer(io_submit.io_end); + return ret; +} + +static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page) +{ + int len; + loff_t size; + int err; + + BUG_ON(page->index != mpd->first_page); + clear_page_dirty_for_io(page); + /* + * We have to be very careful here! Nothing protects writeback path + * against i_size changes and the page can be writeably mapped into + * page tables. So an application can be growing i_size and writing + * data through mmap while writeback runs. clear_page_dirty_for_io() + * write-protects our page in page tables and the page cannot get + * written to again until we release page lock. So only after + * clear_page_dirty_for_io() we are safe to sample i_size for + * ext4_bio_write_page() to zero-out tail of the written page. We rely + * on the barrier provided by TestClearPageDirty in + * clear_page_dirty_for_io() to make sure i_size is really sampled only + * after page tables are updated. + */ + size = i_size_read(mpd->inode); + if (page->index == size >> PAGE_SHIFT) + len = size & ~PAGE_MASK; + else + len = PAGE_SIZE; + err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false); + if (!err) + mpd->wbc->nr_to_write--; + mpd->first_page++; + + return err; +} + +#define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay)) + +/* + * mballoc gives us at most this number of blocks... + * XXX: That seems to be only a limitation of ext4_mb_normalize_request(). + * The rest of mballoc seems to handle chunks up to full group size. + */ +#define MAX_WRITEPAGES_EXTENT_LEN 2048 + +/* + * mpage_add_bh_to_extent - try to add bh to extent of blocks to map + * + * @mpd - extent of blocks + * @lblk - logical number of the block in the file + * @bh - buffer head we want to add to the extent + * + * The function is used to collect contig. blocks in the same state. If the + * buffer doesn't require mapping for writeback and we haven't started the + * extent of buffers to map yet, the function returns 'true' immediately - the + * caller can write the buffer right away. Otherwise the function returns true + * if the block has been added to the extent, false if the block couldn't be + * added. + */ +static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, + struct buffer_head *bh) +{ + struct ext4_map_blocks *map = &mpd->map; + + /* Buffer that doesn't need mapping for writeback? */ + if (!buffer_dirty(bh) || !buffer_mapped(bh) || + (!buffer_delay(bh) && !buffer_unwritten(bh))) { + /* So far no extent to map => we write the buffer right away */ + if (map->m_len == 0) + return true; + return false; + } + + /* First block in the extent? */ + if (map->m_len == 0) { + /* We cannot map unless handle is started... */ + if (!mpd->do_map) + return false; + map->m_lblk = lblk; + map->m_len = 1; + map->m_flags = bh->b_state & BH_FLAGS; + return true; + } + + /* Don't go larger than mballoc is willing to allocate */ + if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN) + return false; + + /* Can we merge the block to our big extent? */ + if (lblk == map->m_lblk + map->m_len && + (bh->b_state & BH_FLAGS) == map->m_flags) { + map->m_len++; + return true; + } + return false; +} + +/* + * mpage_process_page_bufs - submit page buffers for IO or add them to extent + * + * @mpd - extent of blocks for mapping + * @head - the first buffer in the page + * @bh - buffer we should start processing from + * @lblk - logical number of the block in the file corresponding to @bh + * + * Walk through page buffers from @bh upto @head (exclusive) and either submit + * the page for IO if all buffers in this page were mapped and there's no + * accumulated extent of buffers to map or add buffers in the page to the + * extent of buffers to map. The function returns 1 if the caller can continue + * by processing the next page, 0 if it should stop adding buffers to the + * extent to map because we cannot extend it anymore. It can also return value + * < 0 in case of error during IO submission. + */ +static int mpage_process_page_bufs(struct mpage_da_data *mpd, + struct buffer_head *head, + struct buffer_head *bh, + ext4_lblk_t lblk) +{ + struct inode *inode = mpd->inode; + int err; + ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(inode) - 1) + >> inode->i_blkbits; + + do { + BUG_ON(buffer_locked(bh)); + + if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) { + /* Found extent to map? */ + if (mpd->map.m_len) + return 0; + /* Buffer needs mapping and handle is not started? */ + if (!mpd->do_map) + return 0; + /* Everything mapped so far and we hit EOF */ + break; + } + } while (lblk++, (bh = bh->b_this_page) != head); + /* So far everything mapped? Submit the page for IO. */ + if (mpd->map.m_len == 0) { + err = mpage_submit_page(mpd, head->b_page); + if (err < 0) + return err; + } + return lblk < blocks; +} + +/* + * mpage_map_buffers - update buffers corresponding to changed extent and + * submit fully mapped pages for IO + * + * @mpd - description of extent to map, on return next extent to map + * + * Scan buffers corresponding to changed extent (we expect corresponding pages + * to be already locked) and update buffer state according to new extent state. + * We map delalloc buffers to their physical location, clear unwritten bits, + * and mark buffers as uninit when we perform writes to unwritten extents + * and do extent conversion after IO is finished. If the last page is not fully + * mapped, we update @map to the next extent in the last page that needs + * mapping. Otherwise we submit the page for IO. + */ +static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) +{ + struct pagevec pvec; + int nr_pages, i; + struct inode *inode = mpd->inode; + struct buffer_head *head, *bh; + int bpp_bits = PAGE_SHIFT - inode->i_blkbits; + pgoff_t start, end; + ext4_lblk_t lblk; + sector_t pblock; + int err; + + start = mpd->map.m_lblk >> bpp_bits; + end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits; + lblk = start << bpp_bits; + pblock = mpd->map.m_pblk; + + pagevec_init(&pvec); + while (start <= end) { + nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping, + &start, end); + if (nr_pages == 0) + break; + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + + bh = head = page_buffers(page); + do { + if (lblk < mpd->map.m_lblk) + continue; + if (lblk >= mpd->map.m_lblk + mpd->map.m_len) { + /* + * Buffer after end of mapped extent. + * Find next buffer in the page to map. + */ + mpd->map.m_len = 0; + mpd->map.m_flags = 0; + /* + * FIXME: If dioread_nolock supports + * blocksize < pagesize, we need to make + * sure we add size mapped so far to + * io_end->size as the following call + * can submit the page for IO. + */ + err = mpage_process_page_bufs(mpd, head, + bh, lblk); + pagevec_release(&pvec); + if (err > 0) + err = 0; + return err; + } + if (buffer_delay(bh)) { + clear_buffer_delay(bh); + bh->b_blocknr = pblock++; + } + clear_buffer_unwritten(bh); + } while (lblk++, (bh = bh->b_this_page) != head); + + /* + * FIXME: This is going to break if dioread_nolock + * supports blocksize < pagesize as we will try to + * convert potentially unmapped parts of inode. + */ + mpd->io_submit.io_end->size += PAGE_SIZE; + /* Page fully mapped - let IO run! */ + err = mpage_submit_page(mpd, page); + if (err < 0) { + pagevec_release(&pvec); + return err; + } + } + pagevec_release(&pvec); + } + /* Extent fully mapped and matches with page boundary. We are done. */ + mpd->map.m_len = 0; + mpd->map.m_flags = 0; + return 0; +} + +static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd) +{ + struct inode *inode = mpd->inode; + struct ext4_map_blocks *map = &mpd->map; + int get_blocks_flags; + int err, dioread_nolock; + + trace_ext4_da_write_pages_extent(inode, map); + /* + * Call ext4_map_blocks() to allocate any delayed allocation blocks, or + * to convert an unwritten extent to be initialized (in the case + * where we have written into one or more preallocated blocks). It is + * possible that we're going to need more metadata blocks than + * previously reserved. However we must not fail because we're in + * writeback and there is nothing we can do about it so it might result + * in data loss. So use reserved blocks to allocate metadata if + * possible. + * + * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if + * the blocks in question are delalloc blocks. This indicates + * that the blocks and quotas has already been checked when + * the data was copied into the page cache. + */ + get_blocks_flags = EXT4_GET_BLOCKS_CREATE | + EXT4_GET_BLOCKS_METADATA_NOFAIL | + EXT4_GET_BLOCKS_IO_SUBMIT; + dioread_nolock = ext4_should_dioread_nolock(inode); + if (dioread_nolock) + get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT; + if (map->m_flags & (1 << BH_Delay)) + get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE; + + err = ext4_map_blocks(handle, inode, map, get_blocks_flags); + if (err < 0) + return err; + if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) { + if (!mpd->io_submit.io_end->handle && + ext4_handle_valid(handle)) { + mpd->io_submit.io_end->handle = handle->h_rsv_handle; + handle->h_rsv_handle = NULL; + } + ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end); + } + + BUG_ON(map->m_len == 0); + if (map->m_flags & EXT4_MAP_NEW) { + clean_bdev_aliases(inode->i_sb->s_bdev, map->m_pblk, + map->m_len); + } + return 0; +} + +/* + * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length + * mpd->len and submit pages underlying it for IO + * + * @handle - handle for journal operations + * @mpd - extent to map + * @give_up_on_write - we set this to true iff there is a fatal error and there + * is no hope of writing the data. The caller should discard + * dirty pages to avoid infinite loops. + * + * The function maps extent starting at mpd->lblk of length mpd->len. If it is + * delayed, blocks are allocated, if it is unwritten, we may need to convert + * them to initialized or split the described range from larger unwritten + * extent. Note that we need not map all the described range since allocation + * can return less blocks or the range is covered by more unwritten extents. We + * cannot map more because we are limited by reserved transaction credits. On + * the other hand we always make sure that the last touched page is fully + * mapped so that it can be written out (and thus forward progress is + * guaranteed). After mapping we submit all mapped pages for IO. + */ +static int mpage_map_and_submit_extent(handle_t *handle, + struct mpage_da_data *mpd, + bool *give_up_on_write) +{ + struct inode *inode = mpd->inode; + struct ext4_map_blocks *map = &mpd->map; + int err; + loff_t disksize; + int progress = 0; + + mpd->io_submit.io_end->offset = + ((loff_t)map->m_lblk) << inode->i_blkbits; + do { + err = mpage_map_one_extent(handle, mpd); + if (err < 0) { + struct super_block *sb = inode->i_sb; + + if (ext4_forced_shutdown(EXT4_SB(sb)) || + EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED) + goto invalidate_dirty_pages; + /* + * Let the uper layers retry transient errors. + * In the case of ENOSPC, if ext4_count_free_blocks() + * is non-zero, a commit should free up blocks. + */ + if ((err == -ENOMEM) || + (err == -ENOSPC && ext4_count_free_clusters(sb))) { + if (progress) + goto update_disksize; + return err; + } + ext4_msg(sb, KERN_CRIT, + "Delayed block allocation failed for " + "inode %lu at logical offset %llu with" + " max blocks %u with error %d", + inode->i_ino, + (unsigned long long)map->m_lblk, + (unsigned)map->m_len, -err); + ext4_msg(sb, KERN_CRIT, + "This should not happen!! Data will " + "be lost\n"); + if (err == -ENOSPC) + ext4_print_free_blocks(inode); + invalidate_dirty_pages: + *give_up_on_write = true; + return err; + } + progress = 1; + /* + * Update buffer state, submit mapped pages, and get us new + * extent to map + */ + err = mpage_map_and_submit_buffers(mpd); + if (err < 0) + goto update_disksize; + } while (map->m_len); + +update_disksize: + /* + * Update on-disk size after IO is submitted. Races with + * truncate are avoided by checking i_size under i_data_sem. + */ + disksize = ((loff_t)mpd->first_page) << PAGE_SHIFT; + if (disksize > READ_ONCE(EXT4_I(inode)->i_disksize)) { + int err2; + loff_t i_size; + + down_write(&EXT4_I(inode)->i_data_sem); + i_size = i_size_read(inode); + if (disksize > i_size) + disksize = i_size; + if (disksize > EXT4_I(inode)->i_disksize) + EXT4_I(inode)->i_disksize = disksize; + up_write(&EXT4_I(inode)->i_data_sem); + err2 = ext4_mark_inode_dirty(handle, inode); + if (err2) + ext4_error(inode->i_sb, + "Failed to mark inode %lu dirty", + inode->i_ino); + if (!err) + err = err2; + } + return err; +} + +/* + * Calculate the total number of credits to reserve for one writepages + * iteration. This is called from ext4_writepages(). We map an extent of + * up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping + * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN + + * bpp - 1 blocks in bpp different extents. + */ +static int ext4_da_writepages_trans_blocks(struct inode *inode) +{ + int bpp = ext4_journal_blocks_per_page(inode); + + return ext4_meta_trans_blocks(inode, + MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp); +} + +/* + * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages + * and underlying extent to map + * + * @mpd - where to look for pages + * + * Walk dirty pages in the mapping. If they are fully mapped, submit them for + * IO immediately. When we find a page which isn't mapped we start accumulating + * extent of buffers underlying these pages that needs mapping (formed by + * either delayed or unwritten buffers). We also lock the pages containing + * these buffers. The extent found is returned in @mpd structure (starting at + * mpd->lblk with length mpd->len blocks). + * + * Note that this function can attach bios to one io_end structure which are + * neither logically nor physically contiguous. Although it may seem as an + * unnecessary complication, it is actually inevitable in blocksize < pagesize + * case as we need to track IO to all buffers underlying a page in one io_end. + */ +static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) +{ + struct address_space *mapping = mpd->inode->i_mapping; + struct pagevec pvec; + unsigned int nr_pages; + long left = mpd->wbc->nr_to_write; + pgoff_t index = mpd->first_page; + pgoff_t end = mpd->last_page; + int tag; + int i, err = 0; + int blkbits = mpd->inode->i_blkbits; + ext4_lblk_t lblk; + struct buffer_head *head; + + if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages) + tag = PAGECACHE_TAG_TOWRITE; + else + tag = PAGECACHE_TAG_DIRTY; + + pagevec_init(&pvec); + mpd->map.m_len = 0; + mpd->next_page = index; + while (index <= end) { + nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end, + tag); + if (nr_pages == 0) + goto out; + + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + + /* + * Accumulated enough dirty pages? This doesn't apply + * to WB_SYNC_ALL mode. For integrity sync we have to + * keep going because someone may be concurrently + * dirtying pages, and we might have synced a lot of + * newly appeared dirty pages, but have not synced all + * of the old dirty pages. + */ + if (mpd->wbc->sync_mode == WB_SYNC_NONE && left <= 0) + goto out; + + /* If we can't merge this page, we are done. */ + if (mpd->map.m_len > 0 && mpd->next_page != page->index) + goto out; + + lock_page(page); + /* + * If the page is no longer dirty, or its mapping no + * longer corresponds to inode we are writing (which + * means it has been truncated or invalidated), or the + * page is already under writeback and we are not doing + * a data integrity writeback, skip the page + */ + if (!PageDirty(page) || + (PageWriteback(page) && + (mpd->wbc->sync_mode == WB_SYNC_NONE)) || + unlikely(page->mapping != mapping)) { + unlock_page(page); + continue; + } + + wait_on_page_writeback(page); + BUG_ON(PageWriteback(page)); + + /* + * Should never happen but for buggy code in + * other subsystems that call + * set_page_dirty() without properly warning + * the file system first. See [1] for more + * information. + * + * [1] https://lore.kernel.org/linux-mm/20180103100430.GE4911@quack2.suse.cz + */ + if (!page_has_buffers(page)) { + ext4_warning_inode(mpd->inode, "page %lu does not have buffers attached", page->index); + ClearPageDirty(page); + unlock_page(page); + continue; + } + + if (mpd->map.m_len == 0) + mpd->first_page = page->index; + mpd->next_page = page->index + 1; + /* Add all dirty buffers to mpd */ + lblk = ((ext4_lblk_t)page->index) << + (PAGE_SHIFT - blkbits); + head = page_buffers(page); + err = mpage_process_page_bufs(mpd, head, head, lblk); + if (err <= 0) + goto out; + err = 0; + left--; + } + pagevec_release(&pvec); + cond_resched(); + } + return 0; +out: + pagevec_release(&pvec); + return err; +} + +static int ext4_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + pgoff_t writeback_index = 0; + long nr_to_write = wbc->nr_to_write; + int range_whole = 0; + int cycled = 1; + handle_t *handle = NULL; + struct mpage_da_data mpd; + struct inode *inode = mapping->host; + int needed_blocks, rsv_blocks = 0, ret = 0; + struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); + bool done; + struct blk_plug plug; + bool give_up_on_write = false; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + percpu_down_read(&sbi->s_writepages_rwsem); + trace_ext4_writepages(inode, wbc); + + /* + * No pages to write? This is mainly a kludge to avoid starting + * a transaction for special inodes like journal inode on last iput() + * because that could violate lock ordering on umount + */ + if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) + goto out_writepages; + + if (ext4_should_journal_data(inode)) { + ret = generic_writepages(mapping, wbc); + goto out_writepages; + } + + /* + * If the filesystem has aborted, it is read-only, so return + * right away instead of dumping stack traces later on that + * will obscure the real source of the problem. We test + * EXT4_MF_FS_ABORTED instead of sb->s_flag's SB_RDONLY because + * the latter could be true if the filesystem is mounted + * read-only, and in that case, ext4_writepages should + * *never* be called, so if that ever happens, we would want + * the stack trace. + */ + if (unlikely(ext4_forced_shutdown(EXT4_SB(mapping->host->i_sb)) || + sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) { + ret = -EROFS; + goto out_writepages; + } + + if (ext4_should_dioread_nolock(inode)) { + /* + * We may need to convert up to one extent per block in + * the page and we may dirty the inode. + */ + rsv_blocks = 1 + ext4_chunk_trans_blocks(inode, + PAGE_SIZE >> inode->i_blkbits); + } + + /* + * If we have inline data and arrive here, it means that + * we will soon create the block for the 1st page, so + * we'd better clear the inline data here. + */ + if (ext4_has_inline_data(inode)) { + /* Just inode will be modified... */ + handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out_writepages; + } + BUG_ON(ext4_test_inode_state(inode, + EXT4_STATE_MAY_INLINE_DATA)); + ext4_destroy_inline_data(handle, inode); + ext4_journal_stop(handle); + } + + if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) + range_whole = 1; + + if (wbc->range_cyclic) { + writeback_index = mapping->writeback_index; + if (writeback_index) + cycled = 0; + mpd.first_page = writeback_index; + mpd.last_page = -1; + } else { + mpd.first_page = wbc->range_start >> PAGE_SHIFT; + mpd.last_page = wbc->range_end >> PAGE_SHIFT; + } + + mpd.inode = inode; + mpd.wbc = wbc; + ext4_io_submit_init(&mpd.io_submit, wbc); +retry: + if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) + tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page); + done = false; + blk_start_plug(&plug); + + /* + * First writeback pages that don't need mapping - we can avoid + * starting a transaction unnecessarily and also avoid being blocked + * in the block layer on device congestion while having transaction + * started. + */ + mpd.do_map = 0; + mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL); + if (!mpd.io_submit.io_end) { + ret = -ENOMEM; + goto unplug; + } + ret = mpage_prepare_extent_to_map(&mpd); + /* Submit prepared bio */ + ext4_io_submit(&mpd.io_submit); + ext4_put_io_end_defer(mpd.io_submit.io_end); + mpd.io_submit.io_end = NULL; + /* Unlock pages we didn't use */ + mpage_release_unused_pages(&mpd, false); + if (ret < 0) + goto unplug; + + while (!done && mpd.first_page <= mpd.last_page) { + /* For each extent of pages we use new io_end */ + mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL); + if (!mpd.io_submit.io_end) { + ret = -ENOMEM; + break; + } + + /* + * We have two constraints: We find one extent to map and we + * must always write out whole page (makes a difference when + * blocksize < pagesize) so that we don't block on IO when we + * try to write out the rest of the page. Journalled mode is + * not supported by delalloc. + */ + BUG_ON(ext4_should_journal_data(inode)); + needed_blocks = ext4_da_writepages_trans_blocks(inode); + + /* start a new transaction */ + handle = ext4_journal_start_with_reserve(inode, + EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: " + "%ld pages, ino %lu; err %d", __func__, + wbc->nr_to_write, inode->i_ino, ret); + /* Release allocated io_end */ + ext4_put_io_end(mpd.io_submit.io_end); + mpd.io_submit.io_end = NULL; + break; + } + mpd.do_map = 1; + + trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc); + ret = mpage_prepare_extent_to_map(&mpd); + if (!ret) { + if (mpd.map.m_len) + ret = mpage_map_and_submit_extent(handle, &mpd, + &give_up_on_write); + else { + /* + * We scanned the whole range (or exhausted + * nr_to_write), submitted what was mapped and + * didn't find anything needing mapping. We are + * done. + */ + done = true; + } + } + /* + * Caution: If the handle is synchronous, + * ext4_journal_stop() can wait for transaction commit + * to finish which may depend on writeback of pages to + * complete or on page lock to be released. In that + * case, we have to wait until after after we have + * submitted all the IO, released page locks we hold, + * and dropped io_end reference (for extent conversion + * to be able to complete) before stopping the handle. + */ + if (!ext4_handle_valid(handle) || handle->h_sync == 0) { + ext4_journal_stop(handle); + handle = NULL; + mpd.do_map = 0; + } + /* Submit prepared bio */ + ext4_io_submit(&mpd.io_submit); + /* Unlock pages we didn't use */ + mpage_release_unused_pages(&mpd, give_up_on_write); + /* + * Drop our io_end reference we got from init. We have + * to be careful and use deferred io_end finishing if + * we are still holding the transaction as we can + * release the last reference to io_end which may end + * up doing unwritten extent conversion. + */ + if (handle) { + ext4_put_io_end_defer(mpd.io_submit.io_end); + ext4_journal_stop(handle); + } else + ext4_put_io_end(mpd.io_submit.io_end); + mpd.io_submit.io_end = NULL; + + if (ret == -ENOSPC && sbi->s_journal) { + /* + * Commit the transaction which would + * free blocks released in the transaction + * and try again + */ + jbd2_journal_force_commit_nested(sbi->s_journal); + ret = 0; + continue; + } + /* Fatal error - ENOMEM, EIO... */ + if (ret) + break; + } +unplug: + blk_finish_plug(&plug); + if (!ret && !cycled && wbc->nr_to_write > 0) { + cycled = 1; + mpd.last_page = writeback_index - 1; + mpd.first_page = 0; + goto retry; + } + + /* Update index */ + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) + /* + * Set the writeback_index so that range_cyclic + * mode will write it back later + */ + mapping->writeback_index = mpd.first_page; + +out_writepages: + trace_ext4_writepages_result(inode, wbc, ret, + nr_to_write - wbc->nr_to_write); + percpu_up_read(&sbi->s_writepages_rwsem); + return ret; +} + +static int ext4_dax_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + int ret; + long nr_to_write = wbc->nr_to_write; + struct inode *inode = mapping->host; + struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + percpu_down_read(&sbi->s_writepages_rwsem); + trace_ext4_writepages(inode, wbc); + + ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc); + trace_ext4_writepages_result(inode, wbc, ret, + nr_to_write - wbc->nr_to_write); + percpu_up_read(&sbi->s_writepages_rwsem); + return ret; +} + +static int ext4_nonda_switch(struct super_block *sb) +{ + s64 free_clusters, dirty_clusters; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + /* + * switch to non delalloc mode if we are running low + * on free block. The free block accounting via percpu + * counters can get slightly wrong with percpu_counter_batch getting + * accumulated on each CPU without updating global counters + * Delalloc need an accurate free block accounting. So switch + * to non delalloc when we are near to error range. + */ + free_clusters = + percpu_counter_read_positive(&sbi->s_freeclusters_counter); + dirty_clusters = + percpu_counter_read_positive(&sbi->s_dirtyclusters_counter); + /* + * Start pushing delalloc when 1/2 of free blocks are dirty. + */ + if (dirty_clusters && (free_clusters < 2 * dirty_clusters)) + try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE); + + if (2 * free_clusters < 3 * dirty_clusters || + free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) { + /* + * free block count is less than 150% of dirty blocks + * or free blocks is less than watermark + */ + return 1; + } + return 0; +} + +/* We always reserve for an inode update; the superblock could be there too */ +static int ext4_da_write_credits(struct inode *inode, loff_t pos, unsigned len) +{ + if (likely(ext4_has_feature_large_file(inode->i_sb))) + return 1; + + if (pos + len <= 0x7fffffffULL) + return 1; + + /* We might need to update the superblock to set LARGE_FILE */ + return 2; +} + +static int ext4_da_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) +{ + int ret, retries = 0; + struct page *page; + pgoff_t index; + struct inode *inode = mapping->host; + handle_t *handle; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + index = pos >> PAGE_SHIFT; + + if (ext4_nonda_switch(inode->i_sb) || + S_ISLNK(inode->i_mode)) { + *fsdata = (void *)FALL_BACK_TO_NONDELALLOC; + return ext4_write_begin(file, mapping, pos, + len, flags, pagep, fsdata); + } + *fsdata = (void *)0; + trace_ext4_da_write_begin(inode, pos, len, flags); + + if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { + ret = ext4_da_write_inline_data_begin(mapping, inode, + pos, len, flags, + pagep, fsdata); + if (ret < 0) + return ret; + if (ret == 1) + return 0; + } + + /* + * grab_cache_page_write_begin() can take a long time if the + * system is thrashing due to memory pressure, or if the page + * is being written back. So grab it first before we start + * the transaction handle. This also allows us to allocate + * the page (if needed) without using GFP_NOFS. + */ +retry_grab: + page = grab_cache_page_write_begin(mapping, index, flags); + if (!page) + return -ENOMEM; + unlock_page(page); + + /* + * With delayed allocation, we don't log the i_disksize update + * if there is delayed block allocation. But we still need + * to journalling the i_disksize update if writes to the end + * of file which has an already mapped buffer. + */ +retry_journal: + handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, + ext4_da_write_credits(inode, pos, len)); + if (IS_ERR(handle)) { + put_page(page); + return PTR_ERR(handle); + } + + lock_page(page); + if (page->mapping != mapping) { + /* The page got truncated from under us */ + unlock_page(page); + put_page(page); + ext4_journal_stop(handle); + goto retry_grab; + } + /* In case writeback began while the page was unlocked */ + wait_for_stable_page(page); + +#ifdef CONFIG_EXT4_FS_ENCRYPTION + ret = ext4_block_write_begin(page, pos, len, + ext4_da_get_block_prep); +#else + ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep); +#endif + if (ret < 0) { + unlock_page(page); + ext4_journal_stop(handle); + /* + * block_write_begin may have instantiated a few blocks + * outside i_size. Trim these off again. Don't need + * i_size_read because we hold i_mutex. + */ + if (pos + len > inode->i_size) + ext4_truncate_failed_write(inode); + + if (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry_journal; + + put_page(page); + return ret; + } + + *pagep = page; + return ret; +} + +/* + * Check if we should update i_disksize + * when write to the end of file but not require block allocation + */ +static int ext4_da_should_update_i_disksize(struct page *page, + unsigned long offset) +{ + struct buffer_head *bh; + struct inode *inode = page->mapping->host; + unsigned int idx; + int i; + + bh = page_buffers(page); + idx = offset >> inode->i_blkbits; + + for (i = 0; i < idx; i++) + bh = bh->b_this_page; + + if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh)) + return 0; + return 1; +} + +static int ext4_da_write_end(struct file *file, + struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) +{ + struct inode *inode = mapping->host; + int ret = 0, ret2; + handle_t *handle = ext4_journal_current_handle(); + loff_t new_i_size; + unsigned long start, end; + int write_mode = (int)(unsigned long)fsdata; + + if (write_mode == FALL_BACK_TO_NONDELALLOC) + return ext4_write_end(file, mapping, pos, + len, copied, page, fsdata); + + trace_ext4_da_write_end(inode, pos, len, copied); + start = pos & (PAGE_SIZE - 1); + end = start + copied - 1; + + /* + * generic_write_end() will run mark_inode_dirty() if i_size + * changes. So let's piggyback the i_disksize mark_inode_dirty + * into that. + */ + new_i_size = pos + copied; + if (copied && new_i_size > EXT4_I(inode)->i_disksize) { + if (ext4_has_inline_data(inode) || + ext4_da_should_update_i_disksize(page, end)) { + ext4_update_i_disksize(inode, new_i_size); + /* We need to mark inode dirty even if + * new_i_size is less that inode->i_size + * bu greater than i_disksize.(hint delalloc) + */ + ext4_mark_inode_dirty(handle, inode); + } + } + + if (write_mode != CONVERT_INLINE_DATA && + ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) && + ext4_has_inline_data(inode)) + ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied, + page); + else + ret2 = generic_write_end(file, mapping, pos, len, copied, + page, fsdata); + + copied = ret2; + if (ret2 < 0) + ret = ret2; + ret2 = ext4_journal_stop(handle); + if (!ret) + ret = ret2; + + return ret ? ret : copied; +} + +static void ext4_da_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + /* + * Drop reserved blocks + */ + BUG_ON(!PageLocked(page)); + if (!page_has_buffers(page)) + goto out; + + ext4_da_page_release_reservation(page, offset, length); + +out: + ext4_invalidatepage(page, offset, length); + + return; +} + +/* + * Force all delayed allocation blocks to be allocated for a given inode. + */ +int ext4_alloc_da_blocks(struct inode *inode) +{ + trace_ext4_alloc_da_blocks(inode); + + if (!EXT4_I(inode)->i_reserved_data_blocks) + return 0; + + /* + * We do something simple for now. The filemap_flush() will + * also start triggering a write of the data blocks, which is + * not strictly speaking necessary (and for users of + * laptop_mode, not even desirable). However, to do otherwise + * would require replicating code paths in: + * + * ext4_writepages() -> + * write_cache_pages() ---> (via passed in callback function) + * __mpage_da_writepage() --> + * mpage_add_bh_to_extent() + * mpage_da_map_blocks() + * + * The problem is that write_cache_pages(), located in + * mm/page-writeback.c, marks pages clean in preparation for + * doing I/O, which is not desirable if we're not planning on + * doing I/O at all. + * + * We could call write_cache_pages(), and then redirty all of + * the pages by calling redirty_page_for_writepage() but that + * would be ugly in the extreme. So instead we would need to + * replicate parts of the code in the above functions, + * simplifying them because we wouldn't actually intend to + * write out the pages, but rather only collect contiguous + * logical block extents, call the multi-block allocator, and + * then update the buffer heads with the block allocations. + * + * For now, though, we'll cheat by calling filemap_flush(), + * which will map the blocks, and start the I/O, but not + * actually wait for the I/O to complete. + */ + return filemap_flush(inode->i_mapping); +} + +/* + * bmap() is special. It gets used by applications such as lilo and by + * the swapper to find the on-disk block of a specific piece of data. + * + * Naturally, this is dangerous if the block concerned is still in the + * journal. If somebody makes a swapfile on an ext4 data-journaling + * filesystem and enables swap, then they may get a nasty shock when the + * data getting swapped to that swapfile suddenly gets overwritten by + * the original zero's written out previously to the journal and + * awaiting writeback in the kernel's buffer cache. + * + * So, if we see any bmap calls here on a modified, data-journaled file, + * take extra steps to flush any blocks which might be in the cache. + */ +static sector_t ext4_bmap(struct address_space *mapping, sector_t block) +{ + struct inode *inode = mapping->host; + journal_t *journal; + int err; + + /* + * We can get here for an inline file via the FIBMAP ioctl + */ + if (ext4_has_inline_data(inode)) + return 0; + + if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && + test_opt(inode->i_sb, DELALLOC)) { + /* + * With delalloc we want to sync the file + * so that we can make sure we allocate + * blocks for file + */ + filemap_write_and_wait(mapping); + } + + if (EXT4_JOURNAL(inode) && + ext4_test_inode_state(inode, EXT4_STATE_JDATA)) { + /* + * This is a REALLY heavyweight approach, but the use of + * bmap on dirty files is expected to be extremely rare: + * only if we run lilo or swapon on a freshly made file + * do we expect this to happen. + * + * (bmap requires CAP_SYS_RAWIO so this does not + * represent an unprivileged user DOS attack --- we'd be + * in trouble if mortal users could trigger this path at + * will.) + * + * NB. EXT4_STATE_JDATA is not set on files other than + * regular files. If somebody wants to bmap a directory + * or symlink and gets confused because the buffer + * hasn't yet been flushed to disk, they deserve + * everything they get. + */ + + ext4_clear_inode_state(inode, EXT4_STATE_JDATA); + journal = EXT4_JOURNAL(inode); + jbd2_journal_lock_updates(journal); + err = jbd2_journal_flush(journal); + jbd2_journal_unlock_updates(journal); + + if (err) + return 0; + } + + return generic_block_bmap(mapping, block, ext4_get_block); +} + +static int ext4_readpage(struct file *file, struct page *page) +{ + int ret = -EAGAIN; + struct inode *inode = page->mapping->host; + + trace_ext4_readpage(page); + + if (ext4_has_inline_data(inode)) + ret = ext4_readpage_inline(inode, page); + + if (ret == -EAGAIN) + return ext4_mpage_readpages(page->mapping, NULL, page, 1, + false); + + return ret; +} + +static int +ext4_readpages(struct file *file, struct address_space *mapping, + struct list_head *pages, unsigned nr_pages) +{ + struct inode *inode = mapping->host; + + /* If the file has inline data, no need to do readpages. */ + if (ext4_has_inline_data(inode)) + return 0; + + return ext4_mpage_readpages(mapping, pages, NULL, nr_pages, true); +} + +static void ext4_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + trace_ext4_invalidatepage(page, offset, length); + + /* No journalling happens on data buffers when this function is used */ + WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page))); + + block_invalidatepage(page, offset, length); +} + +static int __ext4_journalled_invalidatepage(struct page *page, + unsigned int offset, + unsigned int length) +{ + journal_t *journal = EXT4_JOURNAL(page->mapping->host); + + trace_ext4_journalled_invalidatepage(page, offset, length); + + /* + * If it's a full truncate we just forget about the pending dirtying + */ + if (offset == 0 && length == PAGE_SIZE) + ClearPageChecked(page); + + return jbd2_journal_invalidatepage(journal, page, offset, length); +} + +/* Wrapper for aops... */ +static void ext4_journalled_invalidatepage(struct page *page, + unsigned int offset, + unsigned int length) +{ + WARN_ON(__ext4_journalled_invalidatepage(page, offset, length) < 0); +} + +static int ext4_releasepage(struct page *page, gfp_t wait) +{ + journal_t *journal = EXT4_JOURNAL(page->mapping->host); + + trace_ext4_releasepage(page); + + /* Page has dirty journalled data -> cannot release */ + if (PageChecked(page)) + return 0; + if (journal) + return jbd2_journal_try_to_free_buffers(journal, page, wait); + else + return try_to_free_buffers(page); +} + +static bool ext4_inode_datasync_dirty(struct inode *inode) +{ + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + + if (journal) + return !jbd2_transaction_committed(journal, + EXT4_I(inode)->i_datasync_tid); + /* Any metadata buffers to write? */ + if (!list_empty(&inode->i_mapping->private_list)) + return true; + return inode->i_state & I_DIRTY_DATASYNC; +} + +static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length, + unsigned flags, struct iomap *iomap) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + unsigned int blkbits = inode->i_blkbits; + unsigned long first_block, last_block; + struct ext4_map_blocks map; + bool delalloc = false; + int ret; + + if ((offset >> blkbits) > EXT4_MAX_LOGICAL_BLOCK) + return -EINVAL; + first_block = offset >> blkbits; + last_block = min_t(loff_t, (offset + length - 1) >> blkbits, + EXT4_MAX_LOGICAL_BLOCK); + + if (flags & IOMAP_REPORT) { + if (ext4_has_inline_data(inode)) { + ret = ext4_inline_data_iomap(inode, iomap); + if (ret != -EAGAIN) { + if (ret == 0 && offset >= iomap->length) + ret = -ENOENT; + return ret; + } + } + } else { + if (WARN_ON_ONCE(ext4_has_inline_data(inode))) + return -ERANGE; + } + + map.m_lblk = first_block; + map.m_len = last_block - first_block + 1; + + if (flags & IOMAP_REPORT) { + ret = ext4_map_blocks(NULL, inode, &map, 0); + if (ret < 0) + return ret; + + if (ret == 0) { + ext4_lblk_t end = map.m_lblk + map.m_len - 1; + struct extent_status es; + + ext4_es_find_delayed_extent_range(inode, map.m_lblk, end, &es); + + if (!es.es_len || es.es_lblk > end) { + /* entire range is a hole */ + } else if (es.es_lblk > map.m_lblk) { + /* range starts with a hole */ + map.m_len = es.es_lblk - map.m_lblk; + } else { + ext4_lblk_t offs = 0; + + if (es.es_lblk < map.m_lblk) + offs = map.m_lblk - es.es_lblk; + map.m_lblk = es.es_lblk + offs; + map.m_len = es.es_len - offs; + delalloc = true; + } + } + } else if (flags & IOMAP_WRITE) { + int dio_credits; + handle_t *handle; + int retries = 0; + + /* Trim mapping request to maximum we can map at once for DIO */ + if (map.m_len > DIO_MAX_BLOCKS) + map.m_len = DIO_MAX_BLOCKS; + dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); +retry: + /* + * Either we allocate blocks and then we don't get unwritten + * extent so we have reserved enough credits, or the blocks + * are already allocated and unwritten and in that case + * extent conversion fits in the credits as well. + */ + handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, + dio_credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + ret = ext4_map_blocks(handle, inode, &map, + EXT4_GET_BLOCKS_CREATE_ZERO); + if (ret < 0) { + ext4_journal_stop(handle); + if (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry; + return ret; + } + + /* + * If we added blocks beyond i_size, we need to make sure they + * will get truncated if we crash before updating i_size in + * ext4_iomap_end(). For faults we don't need to do that (and + * even cannot because for orphan list operations inode_lock is + * required) - if we happen to instantiate block beyond i_size, + * it is because we race with truncate which has already added + * the inode to the orphan list. + */ + if (!(flags & IOMAP_FAULT) && first_block + map.m_len > + (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) { + int err; + + err = ext4_orphan_add(handle, inode); + if (err < 0) { + ext4_journal_stop(handle); + return err; + } + } + ext4_journal_stop(handle); + } else { + ret = ext4_map_blocks(NULL, inode, &map, 0); + if (ret < 0) + return ret; + } + + /* + * Writes that span EOF might trigger an I/O size update on completion, + * so consider them to be dirty for the purposes of O_DSYNC, even if + * there is no other metadata changes being made or are pending here. + */ + iomap->flags = 0; + if (ext4_inode_datasync_dirty(inode) || + offset + length > i_size_read(inode)) + iomap->flags |= IOMAP_F_DIRTY; + iomap->bdev = inode->i_sb->s_bdev; + iomap->dax_dev = sbi->s_daxdev; + iomap->offset = (u64)first_block << blkbits; + iomap->length = (u64)map.m_len << blkbits; + + if (ret == 0) { + iomap->type = delalloc ? IOMAP_DELALLOC : IOMAP_HOLE; + iomap->addr = IOMAP_NULL_ADDR; + } else { + if (map.m_flags & EXT4_MAP_MAPPED) { + iomap->type = IOMAP_MAPPED; + } else if (map.m_flags & EXT4_MAP_UNWRITTEN) { + iomap->type = IOMAP_UNWRITTEN; + } else { + WARN_ON_ONCE(1); + return -EIO; + } + iomap->addr = (u64)map.m_pblk << blkbits; + } + + if (map.m_flags & EXT4_MAP_NEW) + iomap->flags |= IOMAP_F_NEW; + + return 0; +} + +static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length, + ssize_t written, unsigned flags, struct iomap *iomap) +{ + int ret = 0; + handle_t *handle; + int blkbits = inode->i_blkbits; + bool truncate = false; + + if (!(flags & IOMAP_WRITE) || (flags & IOMAP_FAULT)) + return 0; + + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto orphan_del; + } + if (ext4_update_inode_size(inode, offset + written)) + ext4_mark_inode_dirty(handle, inode); + /* + * We may need to truncate allocated but not written blocks beyond EOF. + */ + if (iomap->offset + iomap->length > + ALIGN(inode->i_size, 1 << blkbits)) { + ext4_lblk_t written_blk, end_blk; + + written_blk = (offset + written) >> blkbits; + end_blk = (offset + length) >> blkbits; + if (written_blk < end_blk && ext4_can_truncate(inode)) + truncate = true; + } + /* + * Remove inode from orphan list if we were extending a inode and + * everything went fine. + */ + if (!truncate && inode->i_nlink && + !list_empty(&EXT4_I(inode)->i_orphan)) + ext4_orphan_del(handle, inode); + ext4_journal_stop(handle); + if (truncate) { + ext4_truncate_failed_write(inode); +orphan_del: + /* + * If truncate failed early the inode might still be on the + * orphan list; we need to make sure the inode is removed from + * the orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } + return ret; +} + +const struct iomap_ops ext4_iomap_ops = { + .iomap_begin = ext4_iomap_begin, + .iomap_end = ext4_iomap_end, +}; + +static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset, + ssize_t size, void *private) +{ + ext4_io_end_t *io_end = private; + + /* if not async direct IO just return */ + if (!io_end) + return 0; + + ext_debug("ext4_end_io_dio(): io_end 0x%p " + "for inode %lu, iocb 0x%p, offset %llu, size %zd\n", + io_end, io_end->inode->i_ino, iocb, offset, size); + + /* + * Error during AIO DIO. We cannot convert unwritten extents as the + * data was not written. Just clear the unwritten flag and drop io_end. + */ + if (size <= 0) { + ext4_clear_io_unwritten_flag(io_end); + size = 0; + } + io_end->offset = offset; + io_end->size = size; + ext4_put_io_end(io_end); + + return 0; +} + +/* + * Handling of direct IO writes. + * + * For ext4 extent files, ext4 will do direct-io write even to holes, + * preallocated extents, and those write extend the file, no need to + * fall back to buffered IO. + * + * For holes, we fallocate those blocks, mark them as unwritten + * If those blocks were preallocated, we mark sure they are split, but + * still keep the range to write as unwritten. + * + * The unwritten extents will be converted to written when DIO is completed. + * For async direct IO, since the IO may still pending when return, we + * set up an end_io call back function, which will do the conversion + * when async direct IO completed. + * + * If the O_DIRECT write will extend the file then add this inode to the + * orphan list. So recovery will truncate it back to the original size + * if the machine crashes during the write. + * + */ +static ssize_t ext4_direct_IO_write(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + struct ext4_inode_info *ei = EXT4_I(inode); + ssize_t ret; + loff_t offset = iocb->ki_pos; + size_t count = iov_iter_count(iter); + int overwrite = 0; + get_block_t *get_block_func = NULL; + int dio_flags = 0; + loff_t final_size = offset + count; + int orphan = 0; + handle_t *handle; + + if (final_size > inode->i_size || final_size > ei->i_disksize) { + /* Credits for sb + inode write */ + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + goto out; + } + ret = ext4_orphan_add(handle, inode); + if (ret) { + ext4_journal_stop(handle); + goto out; + } + orphan = 1; + ext4_update_i_disksize(inode, inode->i_size); + ext4_journal_stop(handle); + } + + BUG_ON(iocb->private == NULL); + + /* + * Make all waiters for direct IO properly wait also for extent + * conversion. This also disallows race between truncate() and + * overwrite DIO as i_dio_count needs to be incremented under i_mutex. + */ + inode_dio_begin(inode); + + /* If we do a overwrite dio, i_mutex locking can be released */ + overwrite = *((int *)iocb->private); + + if (overwrite) + inode_unlock(inode); + + /* + * For extent mapped files we could direct write to holes and fallocate. + * + * Allocated blocks to fill the hole are marked as unwritten to prevent + * parallel buffered read to expose the stale data before DIO complete + * the data IO. + * + * As to previously fallocated extents, ext4 get_block will just simply + * mark the buffer mapped but still keep the extents unwritten. + * + * For non AIO case, we will convert those unwritten extents to written + * after return back from blockdev_direct_IO. That way we save us from + * allocating io_end structure and also the overhead of offloading + * the extent convertion to a workqueue. + * + * For async DIO, the conversion needs to be deferred when the + * IO is completed. The ext4 end_io callback function will be + * called to take care of the conversion work. Here for async + * case, we allocate an io_end structure to hook to the iocb. + */ + iocb->private = NULL; + if (overwrite) + get_block_func = ext4_dio_get_block_overwrite; + else if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) || + round_down(offset, i_blocksize(inode)) >= inode->i_size) { + get_block_func = ext4_dio_get_block; + dio_flags = DIO_LOCKING | DIO_SKIP_HOLES; + } else if (is_sync_kiocb(iocb)) { + get_block_func = ext4_dio_get_block_unwritten_sync; + dio_flags = DIO_LOCKING; + } else { + get_block_func = ext4_dio_get_block_unwritten_async; + dio_flags = DIO_LOCKING; + } + ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter, + get_block_func, ext4_end_io_dio, NULL, + dio_flags); + + if (ret > 0 && !overwrite && ext4_test_inode_state(inode, + EXT4_STATE_DIO_UNWRITTEN)) { + int err; + /* + * for non AIO case, since the IO is already + * completed, we could do the conversion right here + */ + err = ext4_convert_unwritten_extents(NULL, inode, + offset, ret); + if (err < 0) + ret = err; + ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); + } + + inode_dio_end(inode); + /* take i_mutex locking again if we do a ovewrite dio */ + if (overwrite) + inode_lock(inode); + + if (ret < 0 && final_size > inode->i_size) + ext4_truncate_failed_write(inode); + + /* Handle extending of i_size after direct IO write */ + if (orphan) { + int err; + + /* Credits for sb + inode write */ + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); + if (IS_ERR(handle)) { + /* + * We wrote the data but cannot extend + * i_size. Bail out. In async io case, we do + * not return error here because we have + * already submmitted the corresponding + * bio. Returning error here makes the caller + * think that this IO is done and failed + * resulting in race with bio's completion + * handler. + */ + if (!ret) + ret = PTR_ERR(handle); + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + + goto out; + } + if (inode->i_nlink) + ext4_orphan_del(handle, inode); + if (ret > 0) { + loff_t end = offset + ret; + if (end > inode->i_size || end > ei->i_disksize) { + ext4_update_i_disksize(inode, end); + if (end > inode->i_size) + i_size_write(inode, end); + /* + * We're going to return a positive `ret' + * here due to non-zero-length I/O, so there's + * no way of reporting error returns from + * ext4_mark_inode_dirty() to userspace. So + * ignore it. + */ + ext4_mark_inode_dirty(handle, inode); + } + } + err = ext4_journal_stop(handle); + if (ret == 0) + ret = err; + } +out: + return ret; +} + +static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter) +{ + struct address_space *mapping = iocb->ki_filp->f_mapping; + struct inode *inode = mapping->host; + size_t count = iov_iter_count(iter); + ssize_t ret; + loff_t offset = iocb->ki_pos; + loff_t size = i_size_read(inode); + + if (offset >= size) + return 0; + + /* + * Shared inode_lock is enough for us - it protects against concurrent + * writes & truncates and since we take care of writing back page cache, + * we are protected against page writeback as well. + */ + if (iocb->ki_flags & IOCB_NOWAIT) { + if (!inode_trylock_shared(inode)) + return -EAGAIN; + } else { + inode_lock_shared(inode); + } + + ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, + iocb->ki_pos + count - 1); + if (ret) + goto out_unlock; + ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, + iter, ext4_dio_get_block, NULL, NULL, 0); +out_unlock: + inode_unlock_shared(inode); + return ret; +} + +static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file->f_mapping->host; + size_t count = iov_iter_count(iter); + loff_t offset = iocb->ki_pos; + ssize_t ret; + +#ifdef CONFIG_EXT4_FS_ENCRYPTION + if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) + return 0; +#endif + + /* + * If we are doing data journalling we don't support O_DIRECT + */ + if (ext4_should_journal_data(inode)) + return 0; + + /* Let buffer I/O handle the inline data case. */ + if (ext4_has_inline_data(inode)) + return 0; + + trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); + if (iov_iter_rw(iter) == READ) + ret = ext4_direct_IO_read(iocb, iter); + else + ret = ext4_direct_IO_write(iocb, iter); + trace_ext4_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), ret); + return ret; +} + +/* + * Pages can be marked dirty completely asynchronously from ext4's journalling + * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do + * much here because ->set_page_dirty is called under VFS locks. The page is + * not necessarily locked. + * + * We cannot just dirty the page and leave attached buffers clean, because the + * buffers' dirty state is "definitive". We cannot just set the buffers dirty + * or jbddirty because all the journalling code will explode. + * + * So what we do is to mark the page "pending dirty" and next time writepage + * is called, propagate that into the buffers appropriately. + */ +static int ext4_journalled_set_page_dirty(struct page *page) +{ + SetPageChecked(page); + return __set_page_dirty_nobuffers(page); +} + +static int ext4_set_page_dirty(struct page *page) +{ + WARN_ON_ONCE(!PageLocked(page) && !PageDirty(page)); + WARN_ON_ONCE(!page_has_buffers(page)); + return __set_page_dirty_buffers(page); +} + +static const struct address_space_operations ext4_aops = { + .readpage = ext4_readpage, + .readpages = ext4_readpages, + .writepage = ext4_writepage, + .writepages = ext4_writepages, + .write_begin = ext4_write_begin, + .write_end = ext4_write_end, + .set_page_dirty = ext4_set_page_dirty, + .bmap = ext4_bmap, + .invalidatepage = ext4_invalidatepage, + .releasepage = ext4_releasepage, + .direct_IO = ext4_direct_IO, + .migratepage = buffer_migrate_page, + .is_partially_uptodate = block_is_partially_uptodate, + .error_remove_page = generic_error_remove_page, +}; + +static const struct address_space_operations ext4_journalled_aops = { + .readpage = ext4_readpage, + .readpages = ext4_readpages, + .writepage = ext4_writepage, + .writepages = ext4_writepages, + .write_begin = ext4_write_begin, + .write_end = ext4_journalled_write_end, + .set_page_dirty = ext4_journalled_set_page_dirty, + .bmap = ext4_bmap, + .invalidatepage = ext4_journalled_invalidatepage, + .releasepage = ext4_releasepage, + .direct_IO = ext4_direct_IO, + .is_partially_uptodate = block_is_partially_uptodate, + .error_remove_page = generic_error_remove_page, +}; + +static const struct address_space_operations ext4_da_aops = { + .readpage = ext4_readpage, + .readpages = ext4_readpages, + .writepage = ext4_writepage, + .writepages = ext4_writepages, + .write_begin = ext4_da_write_begin, + .write_end = ext4_da_write_end, + .set_page_dirty = ext4_set_page_dirty, + .bmap = ext4_bmap, + .invalidatepage = ext4_da_invalidatepage, + .releasepage = ext4_releasepage, + .direct_IO = ext4_direct_IO, + .migratepage = buffer_migrate_page, + .is_partially_uptodate = block_is_partially_uptodate, + .error_remove_page = generic_error_remove_page, +}; + +static const struct address_space_operations ext4_dax_aops = { + .writepages = ext4_dax_writepages, + .direct_IO = noop_direct_IO, + .set_page_dirty = noop_set_page_dirty, + .bmap = ext4_bmap, + .invalidatepage = noop_invalidatepage, +}; + +void ext4_set_aops(struct inode *inode) +{ + switch (ext4_inode_journal_mode(inode)) { + case EXT4_INODE_ORDERED_DATA_MODE: + case EXT4_INODE_WRITEBACK_DATA_MODE: + break; + case EXT4_INODE_JOURNAL_DATA_MODE: + inode->i_mapping->a_ops = &ext4_journalled_aops; + return; + default: + BUG(); + } + if (IS_DAX(inode)) + inode->i_mapping->a_ops = &ext4_dax_aops; + else if (test_opt(inode->i_sb, DELALLOC)) + inode->i_mapping->a_ops = &ext4_da_aops; + else + inode->i_mapping->a_ops = &ext4_aops; +} + +static int __ext4_block_zero_page_range(handle_t *handle, + struct address_space *mapping, loff_t from, loff_t length) +{ + ext4_fsblk_t index = from >> PAGE_SHIFT; + unsigned offset = from & (PAGE_SIZE-1); + unsigned blocksize, pos; + ext4_lblk_t iblock; + struct inode *inode = mapping->host; + struct buffer_head *bh; + struct page *page; + int err = 0; + + page = find_or_create_page(mapping, from >> PAGE_SHIFT, + mapping_gfp_constraint(mapping, ~__GFP_FS)); + if (!page) + return -ENOMEM; + + blocksize = inode->i_sb->s_blocksize; + + iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits); + + if (!page_has_buffers(page)) + create_empty_buffers(page, blocksize, 0); + + /* Find the buffer that contains "offset" */ + bh = page_buffers(page); + pos = blocksize; + while (offset >= pos) { + bh = bh->b_this_page; + iblock++; + pos += blocksize; + } + if (buffer_freed(bh)) { + BUFFER_TRACE(bh, "freed: skip"); + goto unlock; + } + if (!buffer_mapped(bh)) { + BUFFER_TRACE(bh, "unmapped"); + ext4_get_block(inode, iblock, bh, 0); + /* unmapped? It's a hole - nothing to do */ + if (!buffer_mapped(bh)) { + BUFFER_TRACE(bh, "still unmapped"); + goto unlock; + } + } + + /* Ok, it's mapped. Make sure it's up-to-date */ + if (PageUptodate(page)) + set_buffer_uptodate(bh); + + if (!buffer_uptodate(bh)) { + err = -EIO; + ll_rw_block(REQ_OP_READ, 0, 1, &bh); + wait_on_buffer(bh); + /* Uhhuh. Read error. Complain and punt. */ + if (!buffer_uptodate(bh)) + goto unlock; + if (S_ISREG(inode->i_mode) && + ext4_encrypted_inode(inode)) { + /* We expect the key to be set. */ + BUG_ON(!fscrypt_has_encryption_key(inode)); + BUG_ON(blocksize != PAGE_SIZE); + WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host, + page, PAGE_SIZE, 0, page->index)); + } + } + if (ext4_should_journal_data(inode)) { + BUFFER_TRACE(bh, "get write access"); + err = ext4_journal_get_write_access(handle, bh); + if (err) + goto unlock; + } + zero_user(page, offset, length); + BUFFER_TRACE(bh, "zeroed end of block"); + + if (ext4_should_journal_data(inode)) { + err = ext4_handle_dirty_metadata(handle, inode, bh); + } else { + err = 0; + mark_buffer_dirty(bh); + if (ext4_should_order_data(inode)) + err = ext4_jbd2_inode_add_write(handle, inode, from, + length); + } + +unlock: + unlock_page(page); + put_page(page); + return err; +} + +/* + * ext4_block_zero_page_range() zeros out a mapping of length 'length' + * starting from file offset 'from'. The range to be zero'd must + * be contained with in one block. If the specified range exceeds + * the end of the block it will be shortened to end of the block + * that cooresponds to 'from' + */ +static int ext4_block_zero_page_range(handle_t *handle, + struct address_space *mapping, loff_t from, loff_t length) +{ + struct inode *inode = mapping->host; + unsigned offset = from & (PAGE_SIZE-1); + unsigned blocksize = inode->i_sb->s_blocksize; + unsigned max = blocksize - (offset & (blocksize - 1)); + + /* + * correct length if it does not fall between + * 'from' and the end of the block + */ + if (length > max || length < 0) + length = max; + + if (IS_DAX(inode)) { + return iomap_zero_range(inode, from, length, NULL, + &ext4_iomap_ops); + } + return __ext4_block_zero_page_range(handle, mapping, from, length); +} + +/* + * ext4_block_truncate_page() zeroes out a mapping from file offset `from' + * up to the end of the block which corresponds to `from'. + * This required during truncate. We need to physically zero the tail end + * of that block so it doesn't yield old data if the file is later grown. + */ +static int ext4_block_truncate_page(handle_t *handle, + struct address_space *mapping, loff_t from) +{ + unsigned offset = from & (PAGE_SIZE-1); + unsigned length; + unsigned blocksize; + struct inode *inode = mapping->host; + + /* If we are processing an encrypted inode during orphan list handling */ + if (ext4_encrypted_inode(inode) && !fscrypt_has_encryption_key(inode)) + return 0; + + blocksize = inode->i_sb->s_blocksize; + length = blocksize - (offset & (blocksize - 1)); + + return ext4_block_zero_page_range(handle, mapping, from, length); +} + +int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode, + loff_t lstart, loff_t length) +{ + struct super_block *sb = inode->i_sb; + struct address_space *mapping = inode->i_mapping; + unsigned partial_start, partial_end; + ext4_fsblk_t start, end; + loff_t byte_end = (lstart + length - 1); + int err = 0; + + partial_start = lstart & (sb->s_blocksize - 1); + partial_end = byte_end & (sb->s_blocksize - 1); + + start = lstart >> sb->s_blocksize_bits; + end = byte_end >> sb->s_blocksize_bits; + + /* Handle partial zero within the single block */ + if (start == end && + (partial_start || (partial_end != sb->s_blocksize - 1))) { + err = ext4_block_zero_page_range(handle, mapping, + lstart, length); + return err; + } + /* Handle partial zero out on the start of the range */ + if (partial_start) { + err = ext4_block_zero_page_range(handle, mapping, + lstart, sb->s_blocksize); + if (err) + return err; + } + /* Handle partial zero out on the end of the range */ + if (partial_end != sb->s_blocksize - 1) + err = ext4_block_zero_page_range(handle, mapping, + byte_end - partial_end, + partial_end + 1); + return err; +} + +int ext4_can_truncate(struct inode *inode) +{ + if (S_ISREG(inode->i_mode)) + return 1; + if (S_ISDIR(inode->i_mode)) + return 1; + if (S_ISLNK(inode->i_mode)) + return !ext4_inode_is_fast_symlink(inode); + return 0; +} + +/* + * We have to make sure i_disksize gets properly updated before we truncate + * page cache due to hole punching or zero range. Otherwise i_disksize update + * can get lost as it may have been postponed to submission of writeback but + * that will never happen after we truncate page cache. + */ +int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset, + loff_t len) +{ + handle_t *handle; + loff_t size = i_size_read(inode); + + WARN_ON(!inode_is_locked(inode)); + if (offset > size || offset + len < size) + return 0; + + if (EXT4_I(inode)->i_disksize >= size) + return 0; + + handle = ext4_journal_start(inode, EXT4_HT_MISC, 1); + if (IS_ERR(handle)) + return PTR_ERR(handle); + ext4_update_i_disksize(inode, size); + ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); + + return 0; +} + +static void ext4_wait_dax_page(struct ext4_inode_info *ei) +{ + up_write(&ei->i_mmap_sem); + schedule(); + down_write(&ei->i_mmap_sem); +} + +int ext4_break_layouts(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct page *page; + int error; + + if (WARN_ON_ONCE(!rwsem_is_locked(&ei->i_mmap_sem))) + return -EINVAL; + + do { + page = dax_layout_busy_page(inode->i_mapping); + if (!page) + return 0; + + error = ___wait_var_event(&page->_refcount, + atomic_read(&page->_refcount) == 1, + TASK_INTERRUPTIBLE, 0, 0, + ext4_wait_dax_page(ei)); + } while (error == 0); + + return error; +} + +/* + * ext4_punch_hole: punches a hole in a file by releasing the blocks + * associated with the given offset and length + * + * @inode: File inode + * @offset: The offset where the hole will begin + * @len: The length of the hole + * + * Returns: 0 on success or negative on failure + */ + +int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) +{ + struct super_block *sb = inode->i_sb; + ext4_lblk_t first_block, stop_block; + struct address_space *mapping = inode->i_mapping; + loff_t first_block_offset, last_block_offset, max_length; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + handle_t *handle; + unsigned int credits; + int ret = 0; + + if (!S_ISREG(inode->i_mode)) + return -EOPNOTSUPP; + + trace_ext4_punch_hole(inode, offset, length, 0); + + ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); + if (ext4_has_inline_data(inode)) { + down_write(&EXT4_I(inode)->i_mmap_sem); + ret = ext4_convert_inline_data(inode); + up_write(&EXT4_I(inode)->i_mmap_sem); + if (ret) + return ret; + } + + /* + * Write out all dirty pages to avoid race conditions + * Then release them. + */ + if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { + ret = filemap_write_and_wait_range(mapping, offset, + offset + length - 1); + if (ret) + return ret; + } + + inode_lock(inode); + + /* No need to punch hole beyond i_size */ + if (offset >= inode->i_size) + goto out_mutex; + + /* + * If the hole extends beyond i_size, set the hole + * to end after the page that contains i_size + */ + if (offset + length > inode->i_size) { + length = inode->i_size + + PAGE_SIZE - (inode->i_size & (PAGE_SIZE - 1)) - + offset; + } + + /* + * For punch hole the length + offset needs to be within one block + * before last range. Adjust the length if it goes beyond that limit. + */ + max_length = sbi->s_bitmap_maxbytes - inode->i_sb->s_blocksize; + if (offset + length > max_length) + length = max_length - offset; + + if (offset & (sb->s_blocksize - 1) || + (offset + length) & (sb->s_blocksize - 1)) { + /* + * Attach jinode to inode for jbd2 if we do any zeroing of + * partial block + */ + ret = ext4_inode_attach_jinode(inode); + if (ret < 0) + goto out_mutex; + + } + + /* Wait all existing dio workers, newcomers will block on i_mutex */ + inode_dio_wait(inode); + + /* + * Prevent page faults from reinstantiating pages we have released from + * page cache. + */ + down_write(&EXT4_I(inode)->i_mmap_sem); + + ret = ext4_break_layouts(inode); + if (ret) + goto out_dio; + + first_block_offset = round_up(offset, sb->s_blocksize); + last_block_offset = round_down((offset + length), sb->s_blocksize) - 1; + + /* Now release the pages and zero block aligned part of pages*/ + if (last_block_offset > first_block_offset) { + ret = ext4_update_disksize_before_punch(inode, offset, length); + if (ret) + goto out_dio; + truncate_pagecache_range(inode, first_block_offset, + last_block_offset); + } + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + credits = ext4_writepage_trans_blocks(inode); + else + credits = ext4_blocks_for_truncate(inode); + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + ext4_std_error(sb, ret); + goto out_dio; + } + + ret = ext4_zero_partial_blocks(handle, inode, offset, + length); + if (ret) + goto out_stop; + + first_block = (offset + sb->s_blocksize - 1) >> + EXT4_BLOCK_SIZE_BITS(sb); + stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); + + /* If there are blocks to remove, do it */ + if (stop_block > first_block) { + + down_write(&EXT4_I(inode)->i_data_sem); + ext4_discard_preallocations(inode); + + ret = ext4_es_remove_extent(inode, first_block, + stop_block - first_block); + if (ret) { + up_write(&EXT4_I(inode)->i_data_sem); + goto out_stop; + } + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + ret = ext4_ext_remove_space(inode, first_block, + stop_block - 1); + else + ret = ext4_ind_remove_space(handle, inode, first_block, + stop_block); + + up_write(&EXT4_I(inode)->i_data_sem); + } + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + + inode->i_mtime = inode->i_ctime = current_time(inode); + ext4_mark_inode_dirty(handle, inode); + if (ret >= 0) + ext4_update_inode_fsync_trans(handle, inode, 1); +out_stop: + ext4_journal_stop(handle); +out_dio: + up_write(&EXT4_I(inode)->i_mmap_sem); +out_mutex: + inode_unlock(inode); + return ret; +} + +int ext4_inode_attach_jinode(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct jbd2_inode *jinode; + + if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal) + return 0; + + jinode = jbd2_alloc_inode(GFP_KERNEL); + spin_lock(&inode->i_lock); + if (!ei->jinode) { + if (!jinode) { + spin_unlock(&inode->i_lock); + return -ENOMEM; + } + ei->jinode = jinode; + jbd2_journal_init_jbd_inode(ei->jinode, inode); + jinode = NULL; + } + spin_unlock(&inode->i_lock); + if (unlikely(jinode != NULL)) + jbd2_free_inode(jinode); + return 0; +} + +/* + * ext4_truncate() + * + * We block out ext4_get_block() block instantiations across the entire + * transaction, and VFS/VM ensures that ext4_truncate() cannot run + * simultaneously on behalf of the same inode. + * + * As we work through the truncate and commit bits of it to the journal there + * is one core, guiding principle: the file's tree must always be consistent on + * disk. We must be able to restart the truncate after a crash. + * + * The file's tree may be transiently inconsistent in memory (although it + * probably isn't), but whenever we close off and commit a journal transaction, + * the contents of (the filesystem + the journal) must be consistent and + * restartable. It's pretty simple, really: bottom up, right to left (although + * left-to-right works OK too). + * + * Note that at recovery time, journal replay occurs *before* the restart of + * truncate against the orphan inode list. + * + * The committed inode has the new, desired i_size (which is the same as + * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see + * that this inode's truncate did not complete and it will again call + * ext4_truncate() to have another go. So there will be instantiated blocks + * to the right of the truncation point in a crashed ext4 filesystem. But + * that's fine - as long as they are linked from the inode, the post-crash + * ext4_truncate() run will find them and release them. + */ +int ext4_truncate(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + unsigned int credits; + int err = 0; + handle_t *handle; + struct address_space *mapping = inode->i_mapping; + + /* + * There is a possibility that we're either freeing the inode + * or it's a completely new inode. In those cases we might not + * have i_mutex locked because it's not necessary. + */ + if (!(inode->i_state & (I_NEW|I_FREEING))) + WARN_ON(!inode_is_locked(inode)); + trace_ext4_truncate_enter(inode); + + if (!ext4_can_truncate(inode)) + return 0; + + ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); + + if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC)) + ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); + + if (ext4_has_inline_data(inode)) { + int has_inline = 1; + + err = ext4_inline_data_truncate(inode, &has_inline); + if (err) + return err; + if (has_inline) + return 0; + } + + /* If we zero-out tail of the page, we have to create jinode for jbd2 */ + if (inode->i_size & (inode->i_sb->s_blocksize - 1)) { + if (ext4_inode_attach_jinode(inode) < 0) + return 0; + } + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + credits = ext4_writepage_trans_blocks(inode); + else + credits = ext4_blocks_for_truncate(inode); + + handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + if (inode->i_size & (inode->i_sb->s_blocksize - 1)) + ext4_block_truncate_page(handle, mapping, inode->i_size); + + /* + * We add the inode to the orphan list, so that if this + * truncate spans multiple transactions, and we crash, we will + * resume the truncate when the filesystem recovers. It also + * marks the inode dirty, to catch the new size. + * + * Implication: the file must always be in a sane, consistent + * truncatable state while each transaction commits. + */ + err = ext4_orphan_add(handle, inode); + if (err) + goto out_stop; + + down_write(&EXT4_I(inode)->i_data_sem); + + ext4_discard_preallocations(inode); + + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + err = ext4_ext_truncate(handle, inode); + else + ext4_ind_truncate(handle, inode); + + up_write(&ei->i_data_sem); + if (err) + goto out_stop; + + if (IS_SYNC(inode)) + ext4_handle_sync(handle); + +out_stop: + /* + * If this was a simple ftruncate() and the file will remain alive, + * then we need to clear up the orphan record which we created above. + * However, if this was a real unlink then we were called by + * ext4_evict_inode(), and we allow that function to clean up the + * orphan info for us. + */ + if (inode->i_nlink) + ext4_orphan_del(handle, inode); + + inode->i_mtime = inode->i_ctime = current_time(inode); + ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); + + trace_ext4_truncate_exit(inode); + return err; +} + +/* + * ext4_get_inode_loc returns with an extra refcount against the inode's + * underlying buffer_head on success. If 'in_mem' is true, we have all + * data in memory that is needed to recreate the on-disk version of this + * inode. + */ +static int __ext4_get_inode_loc(struct inode *inode, + struct ext4_iloc *iloc, int in_mem) +{ + struct ext4_group_desc *gdp; + struct buffer_head *bh; + struct super_block *sb = inode->i_sb; + ext4_fsblk_t block; + int inodes_per_block, inode_offset; + + iloc->bh = NULL; + if (inode->i_ino < EXT4_ROOT_INO || + inode->i_ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)) + return -EFSCORRUPTED; + + iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb); + gdp = ext4_get_group_desc(sb, iloc->block_group, NULL); + if (!gdp) + return -EIO; + + /* + * Figure out the offset within the block group inode table + */ + inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; + inode_offset = ((inode->i_ino - 1) % + EXT4_INODES_PER_GROUP(sb)); + block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block); + iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb); + + bh = sb_getblk(sb, block); + if (unlikely(!bh)) + return -ENOMEM; + if (!buffer_uptodate(bh)) { + lock_buffer(bh); + + /* + * If the buffer has the write error flag, we have failed + * to write out another inode in the same block. In this + * case, we don't have to read the block because we may + * read the old inode data successfully. + */ + if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) + set_buffer_uptodate(bh); + + if (buffer_uptodate(bh)) { + /* someone brought it uptodate while we waited */ + unlock_buffer(bh); + goto has_buffer; + } + + /* + * If we have all information of the inode in memory and this + * is the only valid inode in the block, we need not read the + * block. + */ + if (in_mem) { + struct buffer_head *bitmap_bh; + int i, start; + + start = inode_offset & ~(inodes_per_block - 1); + + /* Is the inode bitmap in cache? */ + bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp)); + if (unlikely(!bitmap_bh)) + goto make_io; + + /* + * If the inode bitmap isn't in cache then the + * optimisation may end up performing two reads instead + * of one, so skip it. + */ + if (!buffer_uptodate(bitmap_bh)) { + brelse(bitmap_bh); + goto make_io; + } + for (i = start; i < start + inodes_per_block; i++) { + if (i == inode_offset) + continue; + if (ext4_test_bit(i, bitmap_bh->b_data)) + break; + } + brelse(bitmap_bh); + if (i == start + inodes_per_block) { + /* all other inodes are free, so skip I/O */ + memset(bh->b_data, 0, bh->b_size); + set_buffer_uptodate(bh); + unlock_buffer(bh); + goto has_buffer; + } + } + +make_io: + /* + * If we need to do any I/O, try to pre-readahead extra + * blocks from the inode table. + */ + if (EXT4_SB(sb)->s_inode_readahead_blks) { + ext4_fsblk_t b, end, table; + unsigned num; + __u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks; + + table = ext4_inode_table(sb, gdp); + /* s_inode_readahead_blks is always a power of 2 */ + b = block & ~((ext4_fsblk_t) ra_blks - 1); + if (table > b) + b = table; + end = b + ra_blks; + num = EXT4_INODES_PER_GROUP(sb); + if (ext4_has_group_desc_csum(sb)) + num -= ext4_itable_unused_count(sb, gdp); + table += num / inodes_per_block; + if (end > table) + end = table; + while (b <= end) + sb_breadahead_unmovable(sb, b++); + } + + /* + * There are other valid inodes in the buffer, this inode + * has in-inode xattrs, or we don't have this inode in memory. + * Read the block from disk. + */ + trace_ext4_load_inode(inode); + get_bh(bh); + bh->b_end_io = end_buffer_read_sync; + submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh); + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) { + EXT4_ERROR_INODE_BLOCK(inode, block, + "unable to read itable block"); + brelse(bh); + return -EIO; + } + } +has_buffer: + iloc->bh = bh; + return 0; +} + +int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) +{ + /* We have all inode data except xattrs in memory here. */ + return __ext4_get_inode_loc(inode, iloc, + !ext4_test_inode_state(inode, EXT4_STATE_XATTR)); +} + +static bool ext4_should_use_dax(struct inode *inode) +{ + if (!test_opt(inode->i_sb, DAX)) + return false; + if (!S_ISREG(inode->i_mode)) + return false; + if (ext4_should_journal_data(inode)) + return false; + if (ext4_has_inline_data(inode)) + return false; + if (ext4_encrypted_inode(inode)) + return false; + return true; +} + +void ext4_set_inode_flags(struct inode *inode) +{ + unsigned int flags = EXT4_I(inode)->i_flags; + unsigned int new_fl = 0; + + if (flags & EXT4_SYNC_FL) + new_fl |= S_SYNC; + if (flags & EXT4_APPEND_FL) + new_fl |= S_APPEND; + if (flags & EXT4_IMMUTABLE_FL) + new_fl |= S_IMMUTABLE; + if (flags & EXT4_NOATIME_FL) + new_fl |= S_NOATIME; + if (flags & EXT4_DIRSYNC_FL) + new_fl |= S_DIRSYNC; + if (ext4_should_use_dax(inode)) + new_fl |= S_DAX; + if (flags & EXT4_ENCRYPT_FL) + new_fl |= S_ENCRYPTED; + inode_set_flags(inode, new_fl, + S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX| + S_ENCRYPTED); +} + +static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode, + struct ext4_inode_info *ei) +{ + blkcnt_t i_blocks ; + struct inode *inode = &(ei->vfs_inode); + struct super_block *sb = inode->i_sb; + + if (ext4_has_feature_huge_file(sb)) { + /* we are using combined 48 bit field */ + i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 | + le32_to_cpu(raw_inode->i_blocks_lo); + if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) { + /* i_blocks represent file system block size */ + return i_blocks << (inode->i_blkbits - 9); + } else { + return i_blocks; + } + } else { + return le32_to_cpu(raw_inode->i_blocks_lo); + } +} + +static inline int ext4_iget_extra_inode(struct inode *inode, + struct ext4_inode *raw_inode, + struct ext4_inode_info *ei) +{ + __le32 *magic = (void *)raw_inode + + EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize; + + if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize + sizeof(__le32) <= + EXT4_INODE_SIZE(inode->i_sb) && + *magic == cpu_to_le32(EXT4_XATTR_MAGIC)) { + ext4_set_inode_state(inode, EXT4_STATE_XATTR); + return ext4_find_inline_data_nolock(inode); + } else + EXT4_I(inode)->i_inline_off = 0; + return 0; +} + +int ext4_get_projid(struct inode *inode, kprojid_t *projid) +{ + if (!ext4_has_feature_project(inode->i_sb)) + return -EOPNOTSUPP; + *projid = EXT4_I(inode)->i_projid; + return 0; +} + +/* + * ext4 has self-managed i_version for ea inodes, it stores the lower 32bit of + * refcount in i_version, so use raw values if inode has EXT4_EA_INODE_FL flag + * set. + */ +static inline void ext4_inode_set_iversion_queried(struct inode *inode, u64 val) +{ + if (unlikely(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) + inode_set_iversion_raw(inode, val); + else + inode_set_iversion_queried(inode, val); +} +static inline u64 ext4_inode_peek_iversion(const struct inode *inode) +{ + if (unlikely(EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL)) + return inode_peek_iversion_raw(inode); + else + return inode_peek_iversion(inode); +} + +struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, + ext4_iget_flags flags, const char *function, + unsigned int line) +{ + struct ext4_iloc iloc; + struct ext4_inode *raw_inode; + struct ext4_inode_info *ei; + struct inode *inode; + journal_t *journal = EXT4_SB(sb)->s_journal; + long ret; + loff_t size; + int block; + uid_t i_uid; + gid_t i_gid; + projid_t i_projid; + + if ((!(flags & EXT4_IGET_SPECIAL) && + (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)) || + (ino < EXT4_ROOT_INO) || + (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) { + if (flags & EXT4_IGET_HANDLE) + return ERR_PTR(-ESTALE); + __ext4_error(sb, function, line, + "inode #%lu: comm %s: iget: illegal inode #", + ino, current->comm); + return ERR_PTR(-EFSCORRUPTED); + } + + inode = iget_locked(sb, ino); + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + + ei = EXT4_I(inode); + iloc.bh = NULL; + + ret = __ext4_get_inode_loc(inode, &iloc, 0); + if (ret < 0) + goto bad_inode; + raw_inode = ext4_raw_inode(&iloc); + + if ((ino == EXT4_ROOT_INO) && (raw_inode->i_links_count == 0)) { + ext4_error_inode(inode, function, line, 0, + "iget: root inode unallocated"); + ret = -EFSCORRUPTED; + goto bad_inode; + } + + if ((flags & EXT4_IGET_HANDLE) && + (raw_inode->i_links_count == 0) && (raw_inode->i_mode == 0)) { + ret = -ESTALE; + goto bad_inode; + } + + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { + ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); + if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > + EXT4_INODE_SIZE(inode->i_sb) || + (ei->i_extra_isize & 3)) { + ext4_error_inode(inode, function, line, 0, + "iget: bad extra_isize %u " + "(inode size %u)", + ei->i_extra_isize, + EXT4_INODE_SIZE(inode->i_sb)); + ret = -EFSCORRUPTED; + goto bad_inode; + } + } else + ei->i_extra_isize = 0; + + /* Precompute checksum seed for inode metadata */ + if (ext4_has_metadata_csum(sb)) { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + __u32 csum; + __le32 inum = cpu_to_le32(inode->i_ino); + __le32 gen = raw_inode->i_generation; + csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum, + sizeof(inum)); + ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen, + sizeof(gen)); + } + + if (!ext4_inode_csum_verify(inode, raw_inode, ei)) { + ext4_error_inode(inode, function, line, 0, + "iget: checksum invalid"); + ret = -EFSBADCRC; + goto bad_inode; + } + + inode->i_mode = le16_to_cpu(raw_inode->i_mode); + i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); + i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); + if (ext4_has_feature_project(sb) && + EXT4_INODE_SIZE(sb) > EXT4_GOOD_OLD_INODE_SIZE && + EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) + i_projid = (projid_t)le32_to_cpu(raw_inode->i_projid); + else + i_projid = EXT4_DEF_PROJID; + + if (!(test_opt(inode->i_sb, NO_UID32))) { + i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; + i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; + } + i_uid_write(inode, i_uid); + i_gid_write(inode, i_gid); + ei->i_projid = make_kprojid(&init_user_ns, i_projid); + set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); + + ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ + ei->i_inline_off = 0; + ei->i_dir_start_lookup = 0; + ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); + /* We now have enough fields to check if the inode was active or not. + * This is needed because nfsd might try to access dead inodes + * the test is that same one that e2fsck uses + * NeilBrown 1999oct15 + */ + if (inode->i_nlink == 0) { + if ((inode->i_mode == 0 || + !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) && + ino != EXT4_BOOT_LOADER_INO) { + /* this inode is deleted */ + ret = -ESTALE; + goto bad_inode; + } + /* The only unlinked inodes we let through here have + * valid i_mode and are being read by the orphan + * recovery code: that's fine, we're about to complete + * the process of deleting those. + * OR it is the EXT4_BOOT_LOADER_INO which is + * not initialized on a new filesystem. */ + } + ei->i_flags = le32_to_cpu(raw_inode->i_flags); + ext4_set_inode_flags(inode); + inode->i_blocks = ext4_inode_blocks(raw_inode, ei); + ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo); + if (ext4_has_feature_64bit(sb)) + ei->i_file_acl |= + ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32; + inode->i_size = ext4_isize(sb, raw_inode); + if ((size = i_size_read(inode)) < 0) { + ext4_error_inode(inode, function, line, 0, + "iget: bad i_size value: %lld", size); + ret = -EFSCORRUPTED; + goto bad_inode; + } + /* + * If dir_index is not enabled but there's dir with INDEX flag set, + * we'd normally treat htree data as empty space. But with metadata + * checksumming that corrupts checksums so forbid that. + */ + if (!ext4_has_feature_dir_index(sb) && ext4_has_metadata_csum(sb) && + ext4_test_inode_flag(inode, EXT4_INODE_INDEX)) { + ext4_error_inode(inode, function, line, 0, + "iget: Dir with htree data on filesystem without dir_index feature."); + ret = -EFSCORRUPTED; + goto bad_inode; + } + ei->i_disksize = inode->i_size; +#ifdef CONFIG_QUOTA + ei->i_reserved_quota = 0; +#endif + inode->i_generation = le32_to_cpu(raw_inode->i_generation); + ei->i_block_group = iloc.block_group; + ei->i_last_alloc_group = ~0; + /* + * NOTE! The in-memory inode i_data array is in little-endian order + * even on big-endian machines: we do NOT byteswap the block numbers! + */ + for (block = 0; block < EXT4_N_BLOCKS; block++) + ei->i_data[block] = raw_inode->i_block[block]; + INIT_LIST_HEAD(&ei->i_orphan); + + /* + * Set transaction id's of transactions that have to be committed + * to finish f[data]sync. We set them to currently running transaction + * as we cannot be sure that the inode or some of its metadata isn't + * part of the transaction - the inode could have been reclaimed and + * now it is reread from disk. + */ + if (journal) { + transaction_t *transaction; + tid_t tid; + + read_lock(&journal->j_state_lock); + if (journal->j_running_transaction) + transaction = journal->j_running_transaction; + else + transaction = journal->j_committing_transaction; + if (transaction) + tid = transaction->t_tid; + else + tid = journal->j_commit_sequence; + read_unlock(&journal->j_state_lock); + ei->i_sync_tid = tid; + ei->i_datasync_tid = tid; + } + + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { + if (ei->i_extra_isize == 0) { + /* The extra space is currently unused. Use it. */ + BUILD_BUG_ON(sizeof(struct ext4_inode) & 3); + ei->i_extra_isize = sizeof(struct ext4_inode) - + EXT4_GOOD_OLD_INODE_SIZE; + } else { + ret = ext4_iget_extra_inode(inode, raw_inode, ei); + if (ret) + goto bad_inode; + } + } + + EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode); + EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode); + EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode); + EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode); + + if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) { + u64 ivers = le32_to_cpu(raw_inode->i_disk_version); + + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) + ivers |= + (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; + } + ext4_inode_set_iversion_queried(inode, ivers); + } + + ret = 0; + if (ei->i_file_acl && + !ext4_inode_block_valid(inode, ei->i_file_acl, 1)) { + ext4_error_inode(inode, function, line, 0, + "iget: bad extended attribute block %llu", + ei->i_file_acl); + ret = -EFSCORRUPTED; + goto bad_inode; + } else if (!ext4_has_inline_data(inode)) { + /* validate the block references in the inode */ + if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || + (S_ISLNK(inode->i_mode) && + !ext4_inode_is_fast_symlink(inode))) { + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + ret = ext4_ext_check_inode(inode); + else + ret = ext4_ind_check_inode(inode); + } + } + if (ret) + goto bad_inode; + + if (S_ISREG(inode->i_mode)) { + inode->i_op = &ext4_file_inode_operations; + inode->i_fop = &ext4_file_operations; + ext4_set_aops(inode); + } else if (S_ISDIR(inode->i_mode)) { + inode->i_op = &ext4_dir_inode_operations; + inode->i_fop = &ext4_dir_operations; + } else if (S_ISLNK(inode->i_mode)) { + /* VFS does not allow setting these so must be corruption */ + if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) { + ext4_error_inode(inode, function, line, 0, + "iget: immutable or append flags " + "not allowed on symlinks"); + ret = -EFSCORRUPTED; + goto bad_inode; + } + if (ext4_encrypted_inode(inode)) { + inode->i_op = &ext4_encrypted_symlink_inode_operations; + ext4_set_aops(inode); + } else if (ext4_inode_is_fast_symlink(inode)) { + inode->i_link = (char *)ei->i_data; + inode->i_op = &ext4_fast_symlink_inode_operations; + nd_terminate_link(ei->i_data, inode->i_size, + sizeof(ei->i_data) - 1); + } else { + inode->i_op = &ext4_symlink_inode_operations; + ext4_set_aops(inode); + } + inode_nohighmem(inode); + } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || + S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { + inode->i_op = &ext4_special_inode_operations; + if (raw_inode->i_block[0]) + init_special_inode(inode, inode->i_mode, + old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); + else + init_special_inode(inode, inode->i_mode, + new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); + } else if (ino == EXT4_BOOT_LOADER_INO) { + make_bad_inode(inode); + } else { + ret = -EFSCORRUPTED; + ext4_error_inode(inode, function, line, 0, + "iget: bogus i_mode (%o)", inode->i_mode); + goto bad_inode; + } + brelse(iloc.bh); + + unlock_new_inode(inode); + return inode; + +bad_inode: + brelse(iloc.bh); + iget_failed(inode); + return ERR_PTR(ret); +} + +static int ext4_inode_blocks_set(handle_t *handle, + struct ext4_inode *raw_inode, + struct ext4_inode_info *ei) +{ + struct inode *inode = &(ei->vfs_inode); + u64 i_blocks = READ_ONCE(inode->i_blocks); + struct super_block *sb = inode->i_sb; + + if (i_blocks <= ~0U) { + /* + * i_blocks can be represented in a 32 bit variable + * as multiple of 512 bytes + */ + raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); + raw_inode->i_blocks_high = 0; + ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); + return 0; + } + if (!ext4_has_feature_huge_file(sb)) + return -EFBIG; + + if (i_blocks <= 0xffffffffffffULL) { + /* + * i_blocks can be represented in a 48 bit variable + * as multiple of 512 bytes + */ + raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); + raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); + ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); + } else { + ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE); + /* i_block is stored in file system block size */ + i_blocks = i_blocks >> (inode->i_blkbits - 9); + raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); + raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); + } + return 0; +} + +struct other_inode { + unsigned long orig_ino; + struct ext4_inode *raw_inode; +}; + +static int other_inode_match(struct inode * inode, unsigned long ino, + void *data) +{ + struct other_inode *oi = (struct other_inode *) data; + + if ((inode->i_ino != ino) || + (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW | + I_DIRTY_INODE)) || + ((inode->i_state & I_DIRTY_TIME) == 0)) + return 0; + spin_lock(&inode->i_lock); + if (((inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW | + I_DIRTY_INODE)) == 0) && + (inode->i_state & I_DIRTY_TIME)) { + struct ext4_inode_info *ei = EXT4_I(inode); + + inode->i_state &= ~I_DIRTY_TIME; + spin_unlock(&inode->i_lock); + + spin_lock(&ei->i_raw_lock); + EXT4_INODE_SET_XTIME(i_ctime, inode, oi->raw_inode); + EXT4_INODE_SET_XTIME(i_mtime, inode, oi->raw_inode); + EXT4_INODE_SET_XTIME(i_atime, inode, oi->raw_inode); + ext4_inode_csum_set(inode, oi->raw_inode, ei); + spin_unlock(&ei->i_raw_lock); + trace_ext4_other_inode_update_time(inode, oi->orig_ino); + return -1; + } + spin_unlock(&inode->i_lock); + return -1; +} + +/* + * Opportunistically update the other time fields for other inodes in + * the same inode table block. + */ +static void ext4_update_other_inodes_time(struct super_block *sb, + unsigned long orig_ino, char *buf) +{ + struct other_inode oi; + unsigned long ino; + int i, inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; + int inode_size = EXT4_INODE_SIZE(sb); + + oi.orig_ino = orig_ino; + /* + * Calculate the first inode in the inode table block. Inode + * numbers are one-based. That is, the first inode in a block + * (assuming 4k blocks and 256 byte inodes) is (n*16 + 1). + */ + ino = ((orig_ino - 1) & ~(inodes_per_block - 1)) + 1; + for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) { + if (ino == orig_ino) + continue; + oi.raw_inode = (struct ext4_inode *) buf; + (void) find_inode_nowait(sb, ino, other_inode_match, &oi); + } +} + +/* + * Post the struct inode info into an on-disk inode location in the + * buffer-cache. This gobbles the caller's reference to the + * buffer_head in the inode location struct. + * + * The caller must have write access to iloc->bh. + */ +static int ext4_do_update_inode(handle_t *handle, + struct inode *inode, + struct ext4_iloc *iloc) +{ + struct ext4_inode *raw_inode = ext4_raw_inode(iloc); + struct ext4_inode_info *ei = EXT4_I(inode); + struct buffer_head *bh = iloc->bh; + struct super_block *sb = inode->i_sb; + int err = 0, block; + int need_datasync = 0, set_large_file = 0; + uid_t i_uid; + gid_t i_gid; + projid_t i_projid; + + spin_lock(&ei->i_raw_lock); + + /* For fields not tracked in the in-memory inode, + * initialise them to zero for new inodes. */ + if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) + memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); + + err = ext4_inode_blocks_set(handle, raw_inode, ei); + if (err) { + spin_unlock(&ei->i_raw_lock); + goto out_brelse; + } + + raw_inode->i_mode = cpu_to_le16(inode->i_mode); + i_uid = i_uid_read(inode); + i_gid = i_gid_read(inode); + i_projid = from_kprojid(&init_user_ns, ei->i_projid); + if (!(test_opt(inode->i_sb, NO_UID32))) { + raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid)); + raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid)); +/* + * Fix up interoperability with old kernels. Otherwise, old inodes get + * re-used with the upper 16 bits of the uid/gid intact + */ + if (ei->i_dtime && list_empty(&ei->i_orphan)) { + raw_inode->i_uid_high = 0; + raw_inode->i_gid_high = 0; + } else { + raw_inode->i_uid_high = + cpu_to_le16(high_16_bits(i_uid)); + raw_inode->i_gid_high = + cpu_to_le16(high_16_bits(i_gid)); + } + } else { + raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid)); + raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid)); + raw_inode->i_uid_high = 0; + raw_inode->i_gid_high = 0; + } + raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); + + EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode); + EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode); + EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode); + EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode); + + raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); + raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF); + if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) + raw_inode->i_file_acl_high = + cpu_to_le16(ei->i_file_acl >> 32); + raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl); + if (READ_ONCE(ei->i_disksize) != ext4_isize(inode->i_sb, raw_inode)) { + ext4_isize_set(raw_inode, ei->i_disksize); + need_datasync = 1; + } + if (ei->i_disksize > 0x7fffffffULL) { + if (!ext4_has_feature_large_file(sb) || + EXT4_SB(sb)->s_es->s_rev_level == + cpu_to_le32(EXT4_GOOD_OLD_REV)) + set_large_file = 1; + } + raw_inode->i_generation = cpu_to_le32(inode->i_generation); + if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { + if (old_valid_dev(inode->i_rdev)) { + raw_inode->i_block[0] = + cpu_to_le32(old_encode_dev(inode->i_rdev)); + raw_inode->i_block[1] = 0; + } else { + raw_inode->i_block[0] = 0; + raw_inode->i_block[1] = + cpu_to_le32(new_encode_dev(inode->i_rdev)); + raw_inode->i_block[2] = 0; + } + } else if (!ext4_has_inline_data(inode)) { + for (block = 0; block < EXT4_N_BLOCKS; block++) + raw_inode->i_block[block] = ei->i_data[block]; + } + + if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) { + u64 ivers = ext4_inode_peek_iversion(inode); + + raw_inode->i_disk_version = cpu_to_le32(ivers); + if (ei->i_extra_isize) { + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) + raw_inode->i_version_hi = + cpu_to_le32(ivers >> 32); + raw_inode->i_extra_isize = + cpu_to_le16(ei->i_extra_isize); + } + } + + BUG_ON(!ext4_has_feature_project(inode->i_sb) && + i_projid != EXT4_DEF_PROJID); + + if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && + EXT4_FITS_IN_INODE(raw_inode, ei, i_projid)) + raw_inode->i_projid = cpu_to_le32(i_projid); + + ext4_inode_csum_set(inode, raw_inode, ei); + spin_unlock(&ei->i_raw_lock); + if (inode->i_sb->s_flags & SB_LAZYTIME) + ext4_update_other_inodes_time(inode->i_sb, inode->i_ino, + bh->b_data); + + BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, NULL, bh); + if (err) + goto out_brelse; + ext4_clear_inode_state(inode, EXT4_STATE_NEW); + if (set_large_file) { + BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access"); + err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); + if (err) + goto out_brelse; + ext4_set_feature_large_file(sb); + ext4_handle_sync(handle); + err = ext4_handle_dirty_super(handle, sb); + } + ext4_update_inode_fsync_trans(handle, inode, need_datasync); +out_brelse: + brelse(bh); + ext4_std_error(inode->i_sb, err); + return err; +} + +/* + * ext4_write_inode() + * + * We are called from a few places: + * + * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files. + * Here, there will be no transaction running. We wait for any running + * transaction to commit. + * + * - Within flush work (sys_sync(), kupdate and such). + * We wait on commit, if told to. + * + * - Within iput_final() -> write_inode_now() + * We wait on commit, if told to. + * + * In all cases it is actually safe for us to return without doing anything, + * because the inode has been copied into a raw inode buffer in + * ext4_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL + * writeback. + * + * Note that we are absolutely dependent upon all inode dirtiers doing the + * right thing: they *must* call mark_inode_dirty() after dirtying info in + * which we are interested. + * + * It would be a bug for them to not do this. The code: + * + * mark_inode_dirty(inode) + * stuff(); + * inode->i_size = expr; + * + * is in error because write_inode() could occur while `stuff()' is running, + * and the new i_size will be lost. Plus the inode will no longer be on the + * superblock's dirty inode list. + */ +int ext4_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + int err; + + if (WARN_ON_ONCE(current->flags & PF_MEMALLOC) || + sb_rdonly(inode->i_sb)) + return 0; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + if (EXT4_SB(inode->i_sb)->s_journal) { + if (ext4_journal_current_handle()) { + jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); + dump_stack(); + return -EIO; + } + + /* + * No need to force transaction in WB_SYNC_NONE mode. Also + * ext4_sync_fs() will force the commit after everything is + * written. + */ + if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync) + return 0; + + err = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal, + EXT4_I(inode)->i_sync_tid); + } else { + struct ext4_iloc iloc; + + err = __ext4_get_inode_loc(inode, &iloc, 0); + if (err) + return err; + /* + * sync(2) will flush the whole buffer cache. No need to do + * it here separately for each inode. + */ + if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync) + sync_dirty_buffer(iloc.bh); + if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) { + EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr, + "IO error syncing inode"); + err = -EIO; + } + brelse(iloc.bh); + } + return err; +} + +/* + * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate + * buffers that are attached to a page stradding i_size and are undergoing + * commit. In that case we have to wait for commit to finish and try again. + */ +static void ext4_wait_for_tail_page_commit(struct inode *inode) +{ + struct page *page; + unsigned offset; + journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + tid_t commit_tid = 0; + int ret; + + offset = inode->i_size & (PAGE_SIZE - 1); + /* + * If the page is fully truncated, we don't need to wait for any commit + * (and we even should not as __ext4_journalled_invalidatepage() may + * strip all buffers from the page but keep the page dirty which can then + * confuse e.g. concurrent ext4_writepage() seeing dirty page without + * buffers). Also we don't need to wait for any commit if all buffers in + * the page remain valid. This is most beneficial for the common case of + * blocksize == PAGESIZE. + */ + if (!offset || offset > (PAGE_SIZE - i_blocksize(inode))) + return; + while (1) { + page = find_lock_page(inode->i_mapping, + inode->i_size >> PAGE_SHIFT); + if (!page) + return; + ret = __ext4_journalled_invalidatepage(page, offset, + PAGE_SIZE - offset); + unlock_page(page); + put_page(page); + if (ret != -EBUSY) + return; + commit_tid = 0; + read_lock(&journal->j_state_lock); + if (journal->j_committing_transaction) + commit_tid = journal->j_committing_transaction->t_tid; + read_unlock(&journal->j_state_lock); + if (commit_tid) + jbd2_log_wait_commit(journal, commit_tid); + } +} + +/* + * ext4_setattr() + * + * Called from notify_change. + * + * We want to trap VFS attempts to truncate the file as soon as + * possible. In particular, we want to make sure that when the VFS + * shrinks i_size, we put the inode on the orphan list and modify + * i_disksize immediately, so that during the subsequent flushing of + * dirty pages and freeing of disk blocks, we can guarantee that any + * commit will leave the blocks being flushed in an unused state on + * disk. (On recovery, the inode will get truncated and the blocks will + * be freed, so we have a strong guarantee that no future commit will + * leave these blocks visible to the user.) + * + * Another thing we have to assure is that if we are in ordered mode + * and inode is still attached to the committing transaction, we must + * we start writeout of all the dirty pages which are being truncated. + * This way we are sure that all the data written in the previous + * transaction are already on disk (truncate waits for pages under + * writeback). + * + * Called with inode->i_mutex down. + */ +int ext4_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct inode *inode = d_inode(dentry); + int error, rc = 0; + int orphan = 0; + const unsigned int ia_valid = attr->ia_valid; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + if (unlikely(IS_IMMUTABLE(inode))) + return -EPERM; + + if (unlikely(IS_APPEND(inode) && + (ia_valid & (ATTR_MODE | ATTR_UID | + ATTR_GID | ATTR_TIMES_SET)))) + return -EPERM; + + error = setattr_prepare(dentry, attr); + if (error) + return error; + + error = fscrypt_prepare_setattr(dentry, attr); + if (error) + return error; + + if (is_quota_modification(inode, attr)) { + error = dquot_initialize(inode); + if (error) + return error; + } + if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) || + (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) { + handle_t *handle; + + /* (user+group)*(old+new) structure, inode write (sb, + * inode block, ? - but truncate inode update has it) */ + handle = ext4_journal_start(inode, EXT4_HT_QUOTA, + (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) + + EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3); + if (IS_ERR(handle)) { + error = PTR_ERR(handle); + goto err_out; + } + + /* dquot_transfer() calls back ext4_get_inode_usage() which + * counts xattr inode references. + */ + down_read(&EXT4_I(inode)->xattr_sem); + error = dquot_transfer(inode, attr); + up_read(&EXT4_I(inode)->xattr_sem); + + if (error) { + ext4_journal_stop(handle); + return error; + } + /* Update corresponding info in inode so that everything is in + * one transaction */ + if (attr->ia_valid & ATTR_UID) + inode->i_uid = attr->ia_uid; + if (attr->ia_valid & ATTR_GID) + inode->i_gid = attr->ia_gid; + error = ext4_mark_inode_dirty(handle, inode); + ext4_journal_stop(handle); + } + + if (attr->ia_valid & ATTR_SIZE) { + handle_t *handle; + loff_t oldsize = inode->i_size; + int shrink = (attr->ia_size <= inode->i_size); + + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + + if (attr->ia_size > sbi->s_bitmap_maxbytes) + return -EFBIG; + } + if (!S_ISREG(inode->i_mode)) + return -EINVAL; + + if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size) + inode_inc_iversion(inode); + + if (ext4_should_order_data(inode) && + (attr->ia_size < inode->i_size)) { + error = ext4_begin_ordered_truncate(inode, + attr->ia_size); + if (error) + goto err_out; + } + if (attr->ia_size != inode->i_size) { + handle = ext4_journal_start(inode, EXT4_HT_INODE, 3); + if (IS_ERR(handle)) { + error = PTR_ERR(handle); + goto err_out; + } + if (ext4_handle_valid(handle) && shrink) { + error = ext4_orphan_add(handle, inode); + orphan = 1; + } + /* + * Update c/mtime on truncate up, ext4_truncate() will + * update c/mtime in shrink case below + */ + if (!shrink) { + inode->i_mtime = current_time(inode); + inode->i_ctime = inode->i_mtime; + } + down_write(&EXT4_I(inode)->i_data_sem); + EXT4_I(inode)->i_disksize = attr->ia_size; + rc = ext4_mark_inode_dirty(handle, inode); + if (!error) + error = rc; + /* + * We have to update i_size under i_data_sem together + * with i_disksize to avoid races with writeback code + * running ext4_wb_update_i_disksize(). + */ + if (!error) + i_size_write(inode, attr->ia_size); + up_write(&EXT4_I(inode)->i_data_sem); + ext4_journal_stop(handle); + if (error) { + if (orphan && inode->i_nlink) + ext4_orphan_del(NULL, inode); + goto err_out; + } + } + if (!shrink) { + pagecache_isize_extended(inode, oldsize, inode->i_size); + } else { + /* + * Blocks are going to be removed from the inode. Wait + * for dio in flight. + */ + inode_dio_wait(inode); + } + if (orphan && ext4_should_journal_data(inode)) + ext4_wait_for_tail_page_commit(inode); + down_write(&EXT4_I(inode)->i_mmap_sem); + + rc = ext4_break_layouts(inode); + if (rc) { + up_write(&EXT4_I(inode)->i_mmap_sem); + error = rc; + goto err_out; + } + + /* + * Truncate pagecache after we've waited for commit + * in data=journal mode to make pages freeable. + */ + truncate_pagecache(inode, inode->i_size); + if (shrink) { + rc = ext4_truncate(inode); + if (rc) + error = rc; + } + up_write(&EXT4_I(inode)->i_mmap_sem); + } + + if (!error) { + setattr_copy(inode, attr); + mark_inode_dirty(inode); + } + + /* + * If the call to ext4_truncate failed to get a transaction handle at + * all, we need to clean up the in-core orphan list manually. + */ + if (orphan && inode->i_nlink) + ext4_orphan_del(NULL, inode); + + if (!error && (ia_valid & ATTR_MODE)) + rc = posix_acl_chmod(inode, inode->i_mode); + +err_out: + ext4_std_error(inode->i_sb, error); + if (!error) + error = rc; + return error; +} + +int ext4_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + struct ext4_inode *raw_inode; + struct ext4_inode_info *ei = EXT4_I(inode); + unsigned int flags; + + if (EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) { + stat->result_mask |= STATX_BTIME; + stat->btime.tv_sec = ei->i_crtime.tv_sec; + stat->btime.tv_nsec = ei->i_crtime.tv_nsec; + } + + flags = ei->i_flags & EXT4_FL_USER_VISIBLE; + if (flags & EXT4_APPEND_FL) + stat->attributes |= STATX_ATTR_APPEND; + if (flags & EXT4_COMPR_FL) + stat->attributes |= STATX_ATTR_COMPRESSED; + if (flags & EXT4_ENCRYPT_FL) + stat->attributes |= STATX_ATTR_ENCRYPTED; + if (flags & EXT4_IMMUTABLE_FL) + stat->attributes |= STATX_ATTR_IMMUTABLE; + if (flags & EXT4_NODUMP_FL) + stat->attributes |= STATX_ATTR_NODUMP; + + stat->attributes_mask |= (STATX_ATTR_APPEND | + STATX_ATTR_COMPRESSED | + STATX_ATTR_ENCRYPTED | + STATX_ATTR_IMMUTABLE | + STATX_ATTR_NODUMP); + + generic_fillattr(inode, stat); + return 0; +} + +int ext4_file_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + struct inode *inode = d_inode(path->dentry); + u64 delalloc_blocks; + + ext4_getattr(path, stat, request_mask, query_flags); + + /* + * If there is inline data in the inode, the inode will normally not + * have data blocks allocated (it may have an external xattr block). + * Report at least one sector for such files, so tools like tar, rsync, + * others don't incorrectly think the file is completely sparse. + */ + if (unlikely(ext4_has_inline_data(inode))) + stat->blocks += (stat->size + 511) >> 9; + + /* + * We can't update i_blocks if the block allocation is delayed + * otherwise in the case of system crash before the real block + * allocation is done, we will have i_blocks inconsistent with + * on-disk file blocks. + * We always keep i_blocks updated together with real + * allocation. But to not confuse with user, stat + * will return the blocks that include the delayed allocation + * blocks for this file. + */ + delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb), + EXT4_I(inode)->i_reserved_data_blocks); + stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9); + return 0; +} + +static int ext4_index_trans_blocks(struct inode *inode, int lblocks, + int pextents) +{ + if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) + return ext4_ind_trans_blocks(inode, lblocks); + return ext4_ext_index_trans_blocks(inode, pextents); +} + +/* + * Account for index blocks, block groups bitmaps and block group + * descriptor blocks if modify datablocks and index blocks + * worse case, the indexs blocks spread over different block groups + * + * If datablocks are discontiguous, they are possible to spread over + * different block groups too. If they are contiguous, with flexbg, + * they could still across block group boundary. + * + * Also account for superblock, inode, quota and xattr blocks + */ +static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, + int pextents) +{ + ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb); + int gdpblocks; + int idxblocks; + int ret = 0; + + /* + * How many index blocks need to touch to map @lblocks logical blocks + * to @pextents physical extents? + */ + idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents); + + ret = idxblocks; + + /* + * Now let's see how many group bitmaps and group descriptors need + * to account + */ + groups = idxblocks + pextents; + gdpblocks = groups; + if (groups > ngroups) + groups = ngroups; + if (groups > EXT4_SB(inode->i_sb)->s_gdb_count) + gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; + + /* bitmaps and block group descriptor blocks */ + ret += groups + gdpblocks; + + /* Blocks for super block, inode, quota and xattr blocks */ + ret += EXT4_META_TRANS_BLOCKS(inode->i_sb); + + return ret; +} + +/* + * Calculate the total number of credits to reserve to fit + * the modification of a single pages into a single transaction, + * which may include multiple chunks of block allocations. + * + * This could be called via ext4_write_begin() + * + * We need to consider the worse case, when + * one new block per extent. + */ +int ext4_writepage_trans_blocks(struct inode *inode) +{ + int bpp = ext4_journal_blocks_per_page(inode); + int ret; + + ret = ext4_meta_trans_blocks(inode, bpp, bpp); + + /* Account for data blocks for journalled mode */ + if (ext4_should_journal_data(inode)) + ret += bpp; + return ret; +} + +/* + * Calculate the journal credits for a chunk of data modification. + * + * This is called from DIO, fallocate or whoever calling + * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks. + * + * journal buffers for data blocks are not included here, as DIO + * and fallocate do no need to journal data buffers. + */ +int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks) +{ + return ext4_meta_trans_blocks(inode, nrblocks, 1); +} + +/* + * The caller must have previously called ext4_reserve_inode_write(). + * Give this, we know that the caller already has write access to iloc->bh. + */ +int ext4_mark_iloc_dirty(handle_t *handle, + struct inode *inode, struct ext4_iloc *iloc) +{ + int err = 0; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) { + put_bh(iloc->bh); + return -EIO; + } + if (IS_I_VERSION(inode)) + inode_inc_iversion(inode); + + /* the do_update_inode consumes one bh->b_count */ + get_bh(iloc->bh); + + /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */ + err = ext4_do_update_inode(handle, inode, iloc); + put_bh(iloc->bh); + return err; +} + +/* + * On success, We end up with an outstanding reference count against + * iloc->bh. This _must_ be cleaned up later. + */ + +int +ext4_reserve_inode_write(handle_t *handle, struct inode *inode, + struct ext4_iloc *iloc) +{ + int err; + + if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) + return -EIO; + + err = ext4_get_inode_loc(inode, iloc); + if (!err) { + BUFFER_TRACE(iloc->bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, iloc->bh); + if (err) { + brelse(iloc->bh); + iloc->bh = NULL; + } + } + ext4_std_error(inode->i_sb, err); + return err; +} + +static int __ext4_expand_extra_isize(struct inode *inode, + unsigned int new_extra_isize, + struct ext4_iloc *iloc, + handle_t *handle, int *no_expand) +{ + struct ext4_inode *raw_inode; + struct ext4_xattr_ibody_header *header; + unsigned int inode_size = EXT4_INODE_SIZE(inode->i_sb); + struct ext4_inode_info *ei = EXT4_I(inode); + int error; + + /* this was checked at iget time, but double check for good measure */ + if ((EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > inode_size) || + (ei->i_extra_isize & 3)) { + EXT4_ERROR_INODE(inode, "bad extra_isize %u (inode size %u)", + ei->i_extra_isize, + EXT4_INODE_SIZE(inode->i_sb)); + return -EFSCORRUPTED; + } + if ((new_extra_isize < ei->i_extra_isize) || + (new_extra_isize < 4) || + (new_extra_isize > inode_size - EXT4_GOOD_OLD_INODE_SIZE)) + return -EINVAL; /* Should never happen */ + + raw_inode = ext4_raw_inode(iloc); + + header = IHDR(inode, raw_inode); + + /* No extended attributes present */ + if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) || + header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) { + memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE + + EXT4_I(inode)->i_extra_isize, 0, + new_extra_isize - EXT4_I(inode)->i_extra_isize); + EXT4_I(inode)->i_extra_isize = new_extra_isize; + return 0; + } + + /* try to expand with EAs present */ + error = ext4_expand_extra_isize_ea(inode, new_extra_isize, + raw_inode, handle); + if (error) { + /* + * Inode size expansion failed; don't try again + */ + *no_expand = 1; + } + + return error; +} + +/* + * Expand an inode by new_extra_isize bytes. + * Returns 0 on success or negative error number on failure. + */ +static int ext4_try_to_expand_extra_isize(struct inode *inode, + unsigned int new_extra_isize, + struct ext4_iloc iloc, + handle_t *handle) +{ + int no_expand; + int error; + + if (ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) + return -EOVERFLOW; + + /* + * In nojournal mode, we can immediately attempt to expand + * the inode. When journaled, we first need to obtain extra + * buffer credits since we may write into the EA block + * with this same handle. If journal_extend fails, then it will + * only result in a minor loss of functionality for that inode. + * If this is felt to be critical, then e2fsck should be run to + * force a large enough s_min_extra_isize. + */ + if (ext4_handle_valid(handle) && + jbd2_journal_extend(handle, + EXT4_DATA_TRANS_BLOCKS(inode->i_sb)) != 0) + return -ENOSPC; + + if (ext4_write_trylock_xattr(inode, &no_expand) == 0) + return -EBUSY; + + error = __ext4_expand_extra_isize(inode, new_extra_isize, &iloc, + handle, &no_expand); + ext4_write_unlock_xattr(inode, &no_expand); + + return error; +} + +int ext4_expand_extra_isize(struct inode *inode, + unsigned int new_extra_isize, + struct ext4_iloc *iloc) +{ + handle_t *handle; + int no_expand; + int error, rc; + + if (ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) { + brelse(iloc->bh); + return -EOVERFLOW; + } + + handle = ext4_journal_start(inode, EXT4_HT_INODE, + EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); + if (IS_ERR(handle)) { + error = PTR_ERR(handle); + brelse(iloc->bh); + return error; + } + + ext4_write_lock_xattr(inode, &no_expand); + + BUFFER_TRACE(iloc->bh, "get_write_access"); + error = ext4_journal_get_write_access(handle, iloc->bh); + if (error) { + brelse(iloc->bh); + goto out_unlock; + } + + error = __ext4_expand_extra_isize(inode, new_extra_isize, iloc, + handle, &no_expand); + + rc = ext4_mark_iloc_dirty(handle, inode, iloc); + if (!error) + error = rc; + +out_unlock: + ext4_write_unlock_xattr(inode, &no_expand); + ext4_journal_stop(handle); + return error; +} + +/* + * What we do here is to mark the in-core inode as clean with respect to inode + * dirtiness (it may still be data-dirty). + * This means that the in-core inode may be reaped by prune_icache + * without having to perform any I/O. This is a very good thing, + * because *any* task may call prune_icache - even ones which + * have a transaction open against a different journal. + * + * Is this cheating? Not really. Sure, we haven't written the + * inode out, but prune_icache isn't a user-visible syncing function. + * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) + * we start and wait on commits. + */ +int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) +{ + struct ext4_iloc iloc; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + int err; + + might_sleep(); + trace_ext4_mark_inode_dirty(inode, _RET_IP_); + err = ext4_reserve_inode_write(handle, inode, &iloc); + if (err) + return err; + + if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize) + ext4_try_to_expand_extra_isize(inode, sbi->s_want_extra_isize, + iloc, handle); + + return ext4_mark_iloc_dirty(handle, inode, &iloc); +} + +/* + * ext4_dirty_inode() is called from __mark_inode_dirty() + * + * We're really interested in the case where a file is being extended. + * i_size has been changed by generic_commit_write() and we thus need + * to include the updated inode in the current transaction. + * + * Also, dquot_alloc_block() will always dirty the inode when blocks + * are allocated to the file. + * + * If the inode is marked synchronous, we don't honour that here - doing + * so would cause a commit on atime updates, which we don't bother doing. + * We handle synchronous inodes at the highest possible level. + * + * If only the I_DIRTY_TIME flag is set, we can skip everything. If + * I_DIRTY_TIME and I_DIRTY_SYNC is set, the only inode fields we need + * to copy into the on-disk inode structure are the timestamp files. + */ +void ext4_dirty_inode(struct inode *inode, int flags) +{ + handle_t *handle; + + if (flags == I_DIRTY_TIME) + return; + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); + if (IS_ERR(handle)) + goto out; + + ext4_mark_inode_dirty(handle, inode); + + ext4_journal_stop(handle); +out: + return; +} + +#if 0 +/* + * Bind an inode's backing buffer_head into this transaction, to prevent + * it from being flushed to disk early. Unlike + * ext4_reserve_inode_write, this leaves behind no bh reference and + * returns no iloc structure, so the caller needs to repeat the iloc + * lookup to mark the inode dirty later. + */ +static int ext4_pin_inode(handle_t *handle, struct inode *inode) +{ + struct ext4_iloc iloc; + + int err = 0; + if (handle) { + err = ext4_get_inode_loc(inode, &iloc); + if (!err) { + BUFFER_TRACE(iloc.bh, "get_write_access"); + err = jbd2_journal_get_write_access(handle, iloc.bh); + if (!err) + err = ext4_handle_dirty_metadata(handle, + NULL, + iloc.bh); + brelse(iloc.bh); + } + } + ext4_std_error(inode->i_sb, err); + return err; +} +#endif + +int ext4_change_inode_journal_flag(struct inode *inode, int val) +{ + journal_t *journal; + handle_t *handle; + int err; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + + /* + * We have to be very careful here: changing a data block's + * journaling status dynamically is dangerous. If we write a + * data block to the journal, change the status and then delete + * that block, we risk forgetting to revoke the old log record + * from the journal and so a subsequent replay can corrupt data. + * So, first we make sure that the journal is empty and that + * nobody is changing anything. + */ + + journal = EXT4_JOURNAL(inode); + if (!journal) + return 0; + if (is_journal_aborted(journal)) + return -EROFS; + + /* Wait for all existing dio workers */ + inode_dio_wait(inode); + + /* + * Before flushing the journal and switching inode's aops, we have + * to flush all dirty data the inode has. There can be outstanding + * delayed allocations, there can be unwritten extents created by + * fallocate or buffered writes in dioread_nolock mode covered by + * dirty data which can be converted only after flushing the dirty + * data (and journalled aops don't know how to handle these cases). + */ + if (val) { + down_write(&EXT4_I(inode)->i_mmap_sem); + err = filemap_write_and_wait(inode->i_mapping); + if (err < 0) { + up_write(&EXT4_I(inode)->i_mmap_sem); + return err; + } + } + + percpu_down_write(&sbi->s_writepages_rwsem); + jbd2_journal_lock_updates(journal); + + /* + * OK, there are no updates running now, and all cached data is + * synced to disk. We are now in a completely consistent state + * which doesn't have anything in the journal, and we know that + * no filesystem updates are running, so it is safe to modify + * the inode's in-core data-journaling state flag now. + */ + + if (val) + ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); + else { + err = jbd2_journal_flush(journal); + if (err < 0) { + jbd2_journal_unlock_updates(journal); + percpu_up_write(&sbi->s_writepages_rwsem); + return err; + } + ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); + } + ext4_set_aops(inode); + + jbd2_journal_unlock_updates(journal); + percpu_up_write(&sbi->s_writepages_rwsem); + + if (val) + up_write(&EXT4_I(inode)->i_mmap_sem); + + /* Finally we can mark the inode as dirty. */ + + handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + err = ext4_mark_inode_dirty(handle, inode); + ext4_handle_sync(handle); + ext4_journal_stop(handle); + ext4_std_error(inode->i_sb, err); + + return err; +} + +static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh) +{ + return !buffer_mapped(bh); +} + +int ext4_page_mkwrite(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + struct page *page = vmf->page; + loff_t size; + unsigned long len; + int ret; + struct file *file = vma->vm_file; + struct inode *inode = file_inode(file); + struct address_space *mapping = inode->i_mapping; + handle_t *handle; + get_block_t *get_block; + int retries = 0; + + if (unlikely(IS_IMMUTABLE(inode))) + return VM_FAULT_SIGBUS; + + sb_start_pagefault(inode->i_sb); + file_update_time(vma->vm_file); + + down_read(&EXT4_I(inode)->i_mmap_sem); + + ret = ext4_convert_inline_data(inode); + if (ret) + goto out_ret; + + /* Delalloc case is easy... */ + if (test_opt(inode->i_sb, DELALLOC) && + !ext4_should_journal_data(inode) && + !ext4_nonda_switch(inode->i_sb)) { + do { + ret = block_page_mkwrite(vma, vmf, + ext4_da_get_block_prep); + } while (ret == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)); + goto out_ret; + } + + lock_page(page); + size = i_size_read(inode); + /* Page got truncated from under us? */ + if (page->mapping != mapping || page_offset(page) > size) { + unlock_page(page); + ret = VM_FAULT_NOPAGE; + goto out; + } + + if (page->index == size >> PAGE_SHIFT) + len = size & ~PAGE_MASK; + else + len = PAGE_SIZE; + /* + * Return if we have all the buffers mapped. This avoids the need to do + * journal_start/journal_stop which can block and take a long time + */ + if (page_has_buffers(page)) { + if (!ext4_walk_page_buffers(NULL, page_buffers(page), + 0, len, NULL, + ext4_bh_unmapped)) { + /* Wait so that we don't change page under IO */ + wait_for_stable_page(page); + ret = VM_FAULT_LOCKED; + goto out; + } + } + unlock_page(page); + /* OK, we need to fill the hole... */ + if (ext4_should_dioread_nolock(inode)) + get_block = ext4_get_block_unwritten; + else + get_block = ext4_get_block; +retry_alloc: + handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, + ext4_writepage_trans_blocks(inode)); + if (IS_ERR(handle)) { + ret = VM_FAULT_SIGBUS; + goto out; + } + ret = block_page_mkwrite(vma, vmf, get_block); + if (!ret && ext4_should_journal_data(inode)) { + if (ext4_walk_page_buffers(handle, page_buffers(page), 0, + PAGE_SIZE, NULL, do_journal_get_write_access)) { + unlock_page(page); + ret = VM_FAULT_SIGBUS; + ext4_journal_stop(handle); + goto out; + } + ext4_set_inode_state(inode, EXT4_STATE_JDATA); + } + ext4_journal_stop(handle); + if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry_alloc; +out_ret: + ret = block_page_mkwrite_return(ret); +out: + up_read(&EXT4_I(inode)->i_mmap_sem); + sb_end_pagefault(inode->i_sb); + return ret; +} + +int ext4_filemap_fault(struct vm_fault *vmf) +{ + struct inode *inode = file_inode(vmf->vma->vm_file); + int err; + + down_read(&EXT4_I(inode)->i_mmap_sem); + err = filemap_fault(vmf); + up_read(&EXT4_I(inode)->i_mmap_sem); + + return err; +} |