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 6449bcdf84ca47465673223fa3a27f88c44684ce..14417baea4425a2566b72da37bfef3780bc65868 100644 (file)
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -118,12 +118,20 @@ static int linear_ioctl(struct dm_target *ti, struct inode *inode,
        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 7830b01ca5847c8b1acc69fb5ffd146d98b609a4..088cf5c1d54edfe54eee6cada33e1d3bb6c6564d 100644 (file)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1421,6 +1421,12 @@ static int multipath_ioctl(struct dm_target *ti, struct inode *inode,
 
        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);
 }