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>
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 6449bcd..14417ba 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -118,12 +118,20 @@
struct block_device *bdev = lc->dev->bdev;
struct file fake_file = {};
struct dentry fake_dentry = {};
+ int r = 0;
fake_file.f_mode = lc->dev->mode;
fake_file.f_path.dentry = &fake_dentry;
fake_dentry.d_inode = bdev->bd_inode;
- return blkdev_driver_ioctl(bdev->bd_inode, &fake_file, bdev->bd_disk, cmd, arg);
+ /*
+ * Only pass ioctls through if the device sizes match exactly.
+ */
+ if (lc->start ||
+ ti->len != i_size_read(bdev->bd_inode) >> SECTOR_SHIFT)
+ r = scsi_verify_blk_ioctl(NULL, cmd);
+
+ return r ? : blkdev_driver_ioctl(bdev->bd_inode, &fake_file, bdev->bd_disk, 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 7830b01..088cf5c 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1421,6 +1421,12 @@
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->bd_inode, &fake_file,
bdev->bd_disk, cmd, arg);
}
