From: Filipe Manana <fdmanana@suse.com> mainline inclusion from mainline-v5.11-rc1 commit 88090ad36a64af1eb5b78d26b2ccd07eedae80b5 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I94K22 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------------ We do not need anymore to start writeback for delalloc of roots that are being snapshotted and wait for it to complete. This was done in commit 609e804d771f59 ("Btrfs: fix file corruption after snapshotting due to mix of buffered/DIO writes") to fix a type of file corruption where files in a snapshot end up having their i_size updated in a non-ordered way, leaving implicit file holes, when buffered IO writes that increase a file's size are followed by direct IO writes that also increase the file's size. This is not needed anymore because we now have a more generic mechanism to prevent a non-ordered i_size update since commit 9ddc959e802bf7 ("btrfs: use the file extent tree infrastructure"), which addresses this scenario involving snapshots as well. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- fs/btrfs/transaction.c | 49 ++++++------------------------------------ 1 file changed, 6 insertions(+), 43 deletions(-) diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index abd67f984fbc..2f89ac8fd5eb 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -2015,10 +2015,8 @@ static void btrfs_cleanup_pending_block_groups(struct btrfs_trans_handle *trans) } } -static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans) +static inline int btrfs_start_delalloc_flush(struct btrfs_fs_info *fs_info) { - struct btrfs_fs_info *fs_info = trans->fs_info; - /* * We use writeback_inodes_sb here because if we used * btrfs_start_delalloc_roots we would deadlock with fs freeze. @@ -2028,50 +2026,15 @@ static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans) * from already being in a transaction and our join_transaction doesn't * have to re-take the fs freeze lock. */ - if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { + if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) writeback_inodes_sb(fs_info->sb, WB_REASON_SYNC); - } else { - struct btrfs_pending_snapshot *pending; - struct list_head *head = &trans->transaction->pending_snapshots; - - /* - * Flush dellaloc for any root that is going to be snapshotted. - * This is done to avoid a corrupted version of files, in the - * snapshots, that had both buffered and direct IO writes (even - * if they were done sequentially) due to an unordered update of - * the inode's size on disk. - */ - list_for_each_entry(pending, head, list) { - int ret; - - ret = btrfs_start_delalloc_snapshot(pending->root); - if (ret) - return ret; - } - } return 0; } -static inline void btrfs_wait_delalloc_flush(struct btrfs_trans_handle *trans) +static inline void btrfs_wait_delalloc_flush(struct btrfs_fs_info *fs_info) { - struct btrfs_fs_info *fs_info = trans->fs_info; - - if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) { + if (btrfs_test_opt(fs_info, FLUSHONCOMMIT)) btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); - } else { - struct btrfs_pending_snapshot *pending; - struct list_head *head = &trans->transaction->pending_snapshots; - - /* - * Wait for any dellaloc that we started previously for the roots - * that are going to be snapshotted. This is to avoid a corrupted - * version of files in the snapshots that had both buffered and - * direct IO writes (even if they were done sequentially). - */ - list_for_each_entry(pending, head, list) - btrfs_wait_ordered_extents(pending->root, - U64_MAX, 0, U64_MAX); - } } int btrfs_commit_transaction(struct btrfs_trans_handle *trans) @@ -2209,7 +2172,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) extwriter_counter_dec(cur_trans, trans->type); - ret = btrfs_start_delalloc_flush(trans); + ret = btrfs_start_delalloc_flush(fs_info); if (ret) goto cleanup_transaction; @@ -2225,7 +2188,7 @@ int btrfs_commit_transaction(struct btrfs_trans_handle *trans) if (ret) goto cleanup_transaction; - btrfs_wait_delalloc_flush(trans); + btrfs_wait_delalloc_flush(fs_info); /* * Wait for all ordered extents started by a fast fsync that joined this -- 2.39.2