dm: do not forward ioctls from logical volumes to the underlying device

commit ec8013beddd717d1740cfefb1a9b900deef85462 upstream.

A logical volume can map to just part of underlying physical volume.
In this case, it must be treated like a partition.

Based on a patch from Alasdair G Kergon.

Cc: Alasdair G Kergon <agk@redhat.com>
Cc: dm-devel@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backport to 2.6.32 - drop change to drivers/md/dm-flakey.c]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 82f7d6e6b1eab551588ae6b8e917622151c4d4ff..7ab302ddd5a6b31a9b27411f1ef0b5fa983ae9e3 100644 (file)
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -116,7 +116,17 @@ static int linear_ioctl(struct dm_target *ti, unsigned int cmd,
                        unsigned long arg)
 {
        struct linear_c *lc = (struct linear_c *) ti->private;
-       return __blkdev_driver_ioctl(lc->dev->bdev, lc->dev->mode, cmd, arg);
+       struct dm_dev *dev = lc->dev;
+       int r = 0;
+
+       /*
+        * Only pass ioctls through if the device sizes match exactly.
+        */
+       if (lc->start ||
+           ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
+               r = scsi_verify_blk_ioctl(NULL, cmd);
+
+       return r ? : __blkdev_driver_ioctl(dev->bdev, dev->mode, cmd, arg);
 }
 
 static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm,

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index b03cd3971830275f240481eb5434e149abbaee71..4ec5fe22892fc69818167e84e42de82ff13d956f 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1464,6 +1464,12 @@ static int multipath_ioctl(struct dm_target *ti, unsigned int cmd,
 
        spin_unlock_irqrestore(&m->lock, flags);
 
+       /*
+        * Only pass ioctls through if the device sizes match exactly.
+        */
+       if (!r && ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
+               r = scsi_verify_blk_ioctl(NULL, cmd);
+
        return r ? : __blkdev_driver_ioctl(bdev, mode, cmd, arg);
 }