From: Darrick J. Wong <djwong@xxxxxxxxxx> In xfs_reflink_fill_cow_hole, there's a debugging assertion that trips if (after cycling the ILOCK to get a transaction) the requeried cow mapping overlaps the start of the area being written. IOWs, it trips if the hole in the cow fork that it's supposed to fill has been filled. This is trivially possible since we cycled ILOCK_EXCL. If we trip the assertion, then we know that cmap is a delalloc extent because @found is false. Fortunately, the bmapi_write call below will convert the delalloc extent to a real unwritten cow fork extent, so all we need to do here is remove the assertion. It turns out that generic/095 trips this pretty regularly with alwayscow mode enabled. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- fs/xfs/xfs_reflink.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index fe46bce8cae6..5535778a98f9 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -416,8 +416,6 @@ xfs_reflink_fill_cow_hole( goto convert; } - ASSERT(cmap->br_startoff > imap->br_startoff); - /* Allocate the entire reservation as unwritten blocks. */ nimaps = 1; error = xfs_bmapi_write(tp, ip, imap->br_startoff, imap->br_blockcount,