From: Filipe Manana fdmanana@suse.com
[ Upstream commit 650c9caba32a0167a018cca0fab32a2965d23513 ]
At btrfs_replace_file_extents(), if we fail to migrate reserved metadata space from the transaction block reserve into the local block reserve, we trigger a BUG_ON(). This is because it should not be possible to have a failure here, as we reserved more space when we started the transaction than the space we want to migrate. However having a BUG_ON() is way too drastic, we can perfectly handle the failure and return the error to the caller. So just do that instead, and add a WARN_ON() to make it easier to notice the failure if it ever happens (which is particularly useful for fstests, and the warning will trigger a failure of a test case).
Reviewed-by: Boris Burkov boris@bur.io Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/file.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ab882ddfb0e8..7db4f08bd8f9 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2766,7 +2766,8 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, min_size, false); - BUG_ON(ret); + if (WARN_ON(ret)) + goto out_trans; trans->block_rsv = rsv;
cur_offset = start; @@ -2885,7 +2886,8 @@ int btrfs_replace_file_extents(struct btrfs_inode *inode,
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, min_size, false); - BUG_ON(ret); /* shouldn't happen */ + if (WARN_ON(ret)) + break; trans->block_rsv = rsv;
cur_offset = drop_args.drop_end;