| From ben@decadent.org.uk Thu Jan 26 10:28:00 2012 |
| From: Ben Hutchings <ben@decadent.org.uk> |
| Date: Tue, 17 Jan 2012 04:07:31 +0000 |
| Subject: dm: do not forward ioctls from logical volumes to the underlying device |
| To: stable@vger.kernel.org |
| Cc: Paolo Bonzini <pbonzini@redhat.com>, Linus Torvalds <torvalds@linux-foundation.org>, linux-kernel@vger.kernel.org, Petr Matousek <pmatouse@redhat.com>, linux-scsi@vger.kernel.org, Jens Axboe <axboe@kernel.dk>, James Bottomley <JBottomley@parallels.com> |
| Message-ID: <1326773251.2819.173.camel@deadeye> |
| |
| |
| From: Paolo Bonzini <pbonzini@redhat.com> |
| |
| 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> |
| |
| --- |
| drivers/md/dm-linear.c | 12 +++++++++++- |
| drivers/md/dm-mpath.c | 6 ++++++ |
| 2 files changed, 17 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/md/dm-linear.c |
| +++ b/drivers/md/dm-linear.c |
| @@ -116,7 +116,17 @@ static int linear_ioctl(struct dm_target |
| 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, |
| --- a/drivers/md/dm-mpath.c |
| +++ b/drivers/md/dm-mpath.c |
| @@ -1464,6 +1464,12 @@ static int multipath_ioctl(struct dm_tar |
| |
| 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); |
| } |
| |