From: Paolo Bonzini <pbonzini@xxxxxxxxxx>
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@xxxxxxxxxx>
Cc: dm-devel@xxxxxxxxxx
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[bwh: Backport to 2.6.32 - drop change to drivers/md/dm-flakey.c]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
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
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
