md faulty: use disk_stack_limits()

in:
fe86cdce block: do not artificially constrain max_sectors for stacking drivers

max_sectors defaults to UINT_MAX.  md faulty wasn't using
disk_stack_limits(), so inherited this large value as well.
This triggered a bug in XFS when stressed over md_faulty, when
a very large bio_alloc() failed.

That was on an older kernel, and I can't reproduce exactly the
same thing upstream, but I think the fix is appropriate in any
case.

Thanks to Mike Snitzer for pointing out the problem.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/faulty.c b/drivers/md/faulty.c
index 45135f69509c89e83b6cc7190f1f25972ae28076..5e7dc772f5deca223ea9142d073cc66785f54b27 100644 (file)
--- a/drivers/md/faulty.c
+++ b/drivers/md/faulty.c
@@ -315,8 +315,11 @@ static int run(struct mddev *mddev)
        }
        conf->nfaults = 0;
 
-       rdev_for_each(rdev, mddev)
+       rdev_for_each(rdev, mddev) {
                conf->rdev = rdev;
+               disk_stack_limits(mddev->gendisk, rdev->bdev,
+                                 rdev->data_offset << 9);
+       }
 
        md_set_array_sectors(mddev, faulty_size(mddev, 0, 0));
        mddev->private = conf;