[1/3] btrfs: zero the buffer before marking it dirty in btrfs_redirty_list_add

Commit Message

Christoph Hellwig May 8, 2023, 2:58 p.m. UTC

btrfs_redirty_list_add zeroes the buffer data and sets the
EXTENT_BUFFER_NO_CHECK to make sure writeback is fine with a bogus
header.  But it does that after already marking the buffer dirty, which
means that writeback could already be looking at the buffer.

Switch the order of operations around so that the buffer is only marked
dirty when we're ready to write it.

Fixes: d3575156f662 ("btrfs: zoned: redirty released extent buffers")
Signed-off-by: Christoph Hellwig <[e-mail]>
---
 fs/btrfs/zoned.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Patch

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index e3fe02aae641f3..7095cfca2fdde1 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1610,11 +1610,11 @@  void btrfs_redirty_list_add(struct btrfs_transaction *trans,
 	    !list_empty(&eb->release_list))
 		return;
 
+	memzero_extent_buffer(eb, 0, eb->len);
+	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
 	set_extent_buffer_dirty(eb);
 	set_extent_bits_nowait(&trans->dirty_pages, eb->start,
 			       eb->start + eb->len - 1, EXTENT_DIRTY);
-	memzero_extent_buffer(eb, 0, eb->len);
-	set_bit(EXTENT_BUFFER_NO_CHECK, &eb->bflags);
 
 	spin_lock(&trans->releasing_ebs_lock);
 	list_add_tail(&eb->release_list, &trans->releasing_ebs);