From cc6f77710a6de6210f9feda7cd53e2f5ee7a7e69 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Mon, 18 Sep 2017 09:41:16 -0700 Subject: [PATCH] xfs: don't unconditionally clear the reflink flag on zero-block files If we have speculative cow preallocations hanging around in the cow fork, don't let a truncate operation clear the reflink flag because if we do then there's a chance we'll forget to free those extents when we destroy the incore inode. Reported-by: Amir Goldstein Reviewed-by: Carlos Maiolino Reviewed-by: Christoph Hellwig Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_inode.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 5599dda4727a..4ec5b7f45401 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -1624,10 +1624,12 @@ xfs_itruncate_extents( goto out; /* - * Clear the reflink flag if we truncated everything. + * Clear the reflink flag if there are no data fork blocks and + * there are no extents staged in the cow fork. */ - if (ip->i_d.di_nblocks == 0 && xfs_is_reflink_inode(ip)) { - ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; + if (xfs_is_reflink_inode(ip) && ip->i_cnextents == 0) { + if (ip->i_d.di_nblocks == 0) + ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; xfs_inode_clear_cowblocks_tag(ip); } -- 2.20.1