xfs: don't perform discard if the given range length is less than block size
authorJie Liu <jeff.liu@oracle.com>
Wed, 20 Nov 2013 08:08:53 +0000 (16:08 +0800)
committerBen Myers <bpm@sgi.com>
Wed, 4 Dec 2013 21:42:52 +0000 (15:42 -0600)
commitf9fd0135610084abef6867d984e9951c3099950d
tree79015c1a36eececfe2e398ed11ab5ca742bf0ffe
parent10f73d27c8e977fb6fbd6058517069be830c6c9a
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>
fs/xfs/xfs_discard.c