[PATCH stable 4/4] dm: do not forward ioctls from logical volumes to the underlying device
From: Ben Hutchings <hidden>
Date: 2012-01-17 04:07:36
Also in:
linux-scsi, lkml
Subsystem:
device-mapper (lvm), the rest · Maintainers:
Alasdair Kergon, Mike Snitzer, Mikulas Patocka, Benjamin Marzinski, Linus Torvalds
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 <redacted> --- drivers/md/dm-linear.c | 12 +++++++++++- drivers/md/dm-mpath.c | 6 ++++++ 2 files changed, 17 insertions(+), 1 deletions(-)
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 82f7d6e..7ab302d 100644
--- 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 b03cd39..4ec5fe2 100644
--- 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); }
--
1.7.8.2