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authorLeon Romanovsky <leon@kernel.org>2024-06-16 10:51:25 +0300
committerLeon Romanovsky <leon@kernel.org>2024-06-16 10:51:25 +0300
commitef5513526bb6a83d7777acf5b79f71d19865563c (patch)
tree830e4616f84969ef55914bca55d69beac5a2543c /fs/btrfs/ordered-data.c
parent2a1251e3dbb2995100b6f351c2452228895386a5 (diff)
parent7fc45cb68696c7213c484ec81892bc8a986fde52 (diff)
Merge branch 'mana-shared' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Leon Romanovsky says: ==================== net: mana: Allow variable size indirection table Like we talked, I created new shared branch for this patch: https://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma.git/log/?h=mana-shared * 'mana-shared' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: net: mana: Allow variable size indirection table ==================== Link: https://lore.kernel.org/all/20240612183051.GE4966@unreal Signed-off-by: Leon Romanovsky <leon@kernel.org>
Diffstat (limited to 'fs/btrfs/ordered-data.c')
-rw-r--r--fs/btrfs/ordered-data.c31
1 files changed, 31 insertions, 0 deletions
diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c
index c5bdd674f55c..35a413ce935d 100644
--- a/fs/btrfs/ordered-data.c
+++ b/fs/btrfs/ordered-data.c
@@ -388,6 +388,37 @@ bool btrfs_finish_ordered_extent(struct btrfs_ordered_extent *ordered,
ret = can_finish_ordered_extent(ordered, page, file_offset, len, uptodate);
spin_unlock_irqrestore(&inode->ordered_tree_lock, flags);
+ /*
+ * If this is a COW write it means we created new extent maps for the
+ * range and they point to unwritten locations if we got an error either
+ * before submitting a bio or during IO.
+ *
+ * We have marked the ordered extent with BTRFS_ORDERED_IOERR, and we
+ * are queuing its completion below. During completion, at
+ * btrfs_finish_one_ordered(), we will drop the extent maps for the
+ * unwritten extents.
+ *
+ * However because completion runs in a work queue we can end up having
+ * a fast fsync running before that. In the case of direct IO, once we
+ * unlock the inode the fsync might start, and we queue the completion
+ * before unlocking the inode. In the case of buffered IO when writeback
+ * finishes (end_bbio_data_write()) we queue the completion, so if the
+ * writeback was triggered by a fast fsync, the fsync might start
+ * logging before ordered extent completion runs in the work queue.
+ *
+ * The fast fsync will log file extent items based on the extent maps it
+ * finds, so if by the time it collects extent maps the ordered extent
+ * completion didn't happen yet, it will log file extent items that
+ * point to unwritten extents, resulting in a corruption if a crash
+ * happens and the log tree is replayed. Note that a fast fsync does not
+ * wait for completion of ordered extents in order to reduce latency.
+ *
+ * Set a flag in the inode so that the next fast fsync will wait for
+ * ordered extents to complete before starting to log.
+ */
+ if (!uptodate && !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
+ set_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags);
+
if (ret)
btrfs_queue_ordered_fn(ordered);
return ret;