From 363e59baa4f76d3f97c0133ff7014cba3d90a7c3 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 14 Dec 2017 15:42:59 -0800 Subject: [PATCH] xfs: don't be so eager to clear the cowblocks tag on truncate Currently, xfs_itruncate_extents clears the cowblocks tag if i_cnextents is zero. This is wrong, since i_cnextents only tracks real extents in the CoW fork, which means that we could have some delayed CoW reservations still in there that will now never get cleaned. Fix a further bug where we /don't/ clear the reflink iflag if there are any attribute blocks -- really, it's only safe to clear the reflink flag if there are no data fork extents and no cow fork extents. Found by adding clonerange to fsstress in xfs/017. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_inode.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index b41952a4ddd8..6f95bdb408ce 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -1487,6 +1487,24 @@ xfs_link( return error; } +/* Clear the reflink flag and the cowblocks tag if possible. */ +static void +xfs_itruncate_clear_reflink_flags( + struct xfs_inode *ip) +{ + struct xfs_ifork *dfork; + struct xfs_ifork *cfork; + + if (!xfs_is_reflink_inode(ip)) + return; + dfork = XFS_IFORK_PTR(ip, XFS_DATA_FORK); + cfork = XFS_IFORK_PTR(ip, XFS_COW_FORK); + if (dfork->if_bytes == 0 && cfork->if_bytes == 0) + ip->i_d.di_flags2 &= ~XFS_DIFLAG2_REFLINK; + if (cfork->if_bytes == 0) + xfs_inode_clear_cowblocks_tag(ip); +} + /* * Free up the underlying blocks past new_size. The new size must be smaller * than the current size. This routine can be used both for the attribute and @@ -1583,15 +1601,7 @@ xfs_itruncate_extents( if (error) goto out; - /* - * Clear the reflink flag if there are no data fork blocks and - * there are no extents staged in the cow fork. - */ - 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); - } + xfs_itruncate_clear_reflink_flags(ip); /* * Always re-log the inode so that our permanent transaction can keep -- 2.30.2