Commit 2f42d612 authored Nov 20, 2013 by Jie Liu Committed by Ben Myers Dec 10, 2013

xfs: don't perform discard if the given range length is less than block size



For discard operation, we should return EINVAL if the given range length
is less than a block size, otherwise it will go through the file system
to discard data blocks as the end range might be evaluated to -1, e.g,
# fstrim -v -o 0 -l 100 /xfs7
/xfs7: 9811378176 bytes were trimmed

This issue can be triggered via xfstests/generic/288.

Also, it seems to get the request queue pointer via bdev_get_queue()
instead of the hard code pointer dereference is not a bad thing.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit f9fd0135)

parent 31978b5c

fs/xfs/xfs_discard.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -157,7 +157,7 @@ xfs_ioc_trim(
		struct xfs_mount *mp,
		struct fstrim_range __user *urange)
		{
		struct request_queue *q = mp->m_ddev_targp->bt_bdev->bd_disk->queue;
		struct request_queue *q = bdev_get_queue(mp->m_ddev_targp->bt_bdev);
		unsigned int granularity = q->limits.discard_granularity;
		struct fstrim_range range;
		xfs_daddr_t start, end, minlen;
		@@ -180,7 +180,8 @@ xfs_ioc_trim(
		* matter as trimming blocks is an advisory interface.
		*/
		if (range.start >= XFS_FSB_TO_B(mp, mp->m_sb.sb_dblocks) \|\|
		range.minlen > XFS_FSB_TO_B(mp, XFS_ALLOC_AG_MAX_USABLE(mp)))
		range.minlen > XFS_FSB_TO_B(mp, XFS_ALLOC_AG_MAX_USABLE(mp)) \|\|
		range.len < mp->m_sb.sb_blocksize)
		return -XFS_ERROR(EINVAL);

		start = BTOBB(range.start);