[PATCH v3] btrfs: don't BUG_ON() NOCOW ordered-extents with checksum list

[Johannes Thumshirn]

From: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>

Currently we BUG_ON() in btrfs_finish_one_ordered() if we finishing an
ordered-extent that is flagged as NOCOW, but it's checsum list is non-empty.

This is clearly a logic error which we can recover from by aborting the
transaction.

For developer builds which enable CONFIG_BTRFS_ASSERT, also ASSERT() that the
list is empty.

Suggested-by: Filipe Manana <fdmanana@xxxxxxxx>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
---
Changes to v2:
* Move ASSERT() out of if () block (Filipe)
* goto 'out' after aborting the transaction (Filipe)

Changes to v1:
* Fixup if () and ASSERT() (Qu)
* Fix spelling of 'Currently'
---
 fs/btrfs/inode.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 103ec917ca9d..ef82579dfe09 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3088,7 +3088,12 @@ int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent)
 
 	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
 		/* Logic error */
-		BUG_ON(!list_empty(&ordered_extent->list));
+		ASSERT(list_empty(&ordered_extent->list));
+		if (!list_empty(&ordered_extent->list)) {
+			ret = -EINVAL;
+			btrfs_abort_transaction(trans, ret);
+			goto out;
+		}
 
 		btrfs_inode_safe_disk_i_size_write(inode, 0);
 		ret = btrfs_update_inode_fallback(trans, inode);
-- 
2.43.0