diff mbox series

[v2,1/2] xfs: don't free rt blocks when we're doing a REMAP bunmapi call

Message ID 20200918021450.GU7955@magnolia
State New
Headers show
Series [v2,1/2] xfs: don't free rt blocks when we're doing a REMAP bunmapi call | expand

Commit Message

Darrick J. Wong Sept. 18, 2020, 2:14 a.m. UTC
From: Darrick J. Wong <darrick.wong@oracle.com>

When callers pass XFS_BMAPI_REMAP into xfs_bunmapi, they want the extent
to be unmapped from the given file fork without the extent being freed.
We do this for non-rt files, but we forgot to do this for realtime
files.  So far this isn't a big deal since nobody makes a bunmapi call
to a rt file with the REMAP flag set, but don't leave a logic bomb.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
v2: only compute bno if we're going to use it
---
 fs/xfs/libxfs/xfs_bmap.c |   19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

Comments

Christoph Hellwig Sept. 19, 2020, 5:14 a.m. UTC | #1
On Thu, Sep 17, 2020 at 07:14:50PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> When callers pass XFS_BMAPI_REMAP into xfs_bunmapi, they want the extent
> to be unmapped from the given file fork without the extent being freed.
> We do this for non-rt files, but we forgot to do this for realtime
> files.  So far this isn't a big deal since nobody makes a bunmapi call
> to a rt file with the REMAP flag set, but don't leave a logic bomb.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
Dave Chinner Sept. 21, 2020, 6:51 a.m. UTC | #2
On Thu, Sep 17, 2020 at 07:14:50PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> When callers pass XFS_BMAPI_REMAP into xfs_bunmapi, they want the extent
> to be unmapped from the given file fork without the extent being freed.
> We do this for non-rt files, but we forgot to do this for realtime
> files.  So far this isn't a big deal since nobody makes a bunmapi call
> to a rt file with the REMAP flag set, but don't leave a logic bomb.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---
> v2: only compute bno if we're going to use it
> ---
>  fs/xfs/libxfs/xfs_bmap.c |   19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)

Looks fine.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff mbox series

Patch

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 1b0a01b06a05..d9a692484eae 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5046,20 +5046,25 @@  xfs_bmap_del_extent_real(
 
 	flags = XFS_ILOG_CORE;
 	if (whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip)) {
-		xfs_fsblock_t	bno;
 		xfs_filblks_t	len;
 		xfs_extlen_t	mod;
 
-		bno = div_u64_rem(del->br_startblock, mp->m_sb.sb_rextsize,
-				  &mod);
-		ASSERT(mod == 0);
 		len = div_u64_rem(del->br_blockcount, mp->m_sb.sb_rextsize,
 				  &mod);
 		ASSERT(mod == 0);
 
-		error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
-		if (error)
-			goto done;
+		if (!(bflags & XFS_BMAPI_REMAP)) {
+			xfs_fsblock_t	bno;
+
+			bno = div_u64_rem(del->br_startblock,
+					mp->m_sb.sb_rextsize, &mod);
+			ASSERT(mod == 0);
+
+			error = xfs_rtfree_extent(tp, bno, (xfs_extlen_t)len);
+			if (error)
+				goto done;
+		}
+
 		do_fx = 0;
 		nblks = len * mp->m_sb.sb_rextsize;
 		qfield = XFS_TRANS_DQ_RTBCOUNT;