xfs: check if device support discard in xfs_ioc_trim()
PATCH 1/1 xfs: check if device support discard in xfs_ioc_trim()
Right now we, are relying on the fact that when we attempt to actually do the discard, blkdev_issue_discar() returns -EOPNOTSUPP and the user is informed that the device does not support discard.
However, in the case where the we do not hit any suitable free extent to trim in FITRIM code, it will finish without any error. This is very confusing, because it seems that FITRIM was successful even though the device does not actually supports discard.
Solution: Check for the discard support before attempt to search for free extents.
--- fs/xfs/linux-2.6/xfs_discard.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
fs/xfs/linux-2.6/xfs_discard.c +2 -0
@@ -152,6 +152,8 @@ xfs_ioc_trim(if (!capable (CAP_SYS_ADMIN ))return -XFS_ERROR (EPERM ); +if (!blk_queue_discard (q)) +return -XFS_ERROR (EOPNOTSUPP );if (copy_from_user (&range, urange,sizeof (range)))return -XFS_ERROR (EFAULT );
Signature · 6 lines
1.7.4 _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs
Quoted 22 lines · Lukas Czerner
Right now we, are relying on the fact that when we attempt to actually do the discard,
blkdev_issue_discar()returns-EOPNOTSUPPand the user is informed that the device does not support discard.However, in the case where the we do not hit any suitable free extent to trim in FITRIM code, it will finish without any error. This is very confusing, because it seems that FITRIM was successful even though the device does not actually supports discard.
Solution: Check for the discard support before attempt to search for free extents.
Signed-off-by Lukas Czerner <[email protected]>--- fs/xfs/linux-2.6/xfs_discard.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)fs/xfs/linux-2.6/xfs_discard.c +0
-0
fs/xfs/linux-2.6/xfs_discard.c xfs_ioc_trim( · line 159
Quoted 8 lines
fs/xfs/linux-2.6/xfs_discard.c +2
-0@@ -152,6 +152,8 @@ xfs_ioc_trim(if (!capable (CAP_SYS_ADMIN ))return -XFS_ERROR (EPERM ); +if (!blk_queue_discard (q)) +return -XFS_ERROR (EOPNOTSUPP );if (copy_from_user (&range, urange,sizeof (range)))return -XFS_ERROR (EFAULT );
Looks good.
_______________________________________________
xfs mailing list
[email protected]
http://oss.sgi.com/mailman/listinfo/xfs