[092/129] dm: do not forward ioctls from logical volumes to theunderlying device

From: Greg KH
Date: Mon Jan 23 2012 - 21:58:40 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------
Content-Length: 2491
Lines: 79

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
drivers/md/dm-flakey.c | 11 ++++++++++-
drivers/md/dm-linear.c | 12 +++++++++++-
drivers/md/dm-mpath.c | 6 ++++++
3 files changed, 27 insertions(+), 2 deletions(-)

--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -368,8 +368,17 @@ static int flakey_status(struct dm_targe
static int flakey_ioctl(struct dm_target *ti, unsigned int cmd, unsigned long arg)
{
struct flakey_c *fc = ti->private;
+ struct dm_dev *dev = fc->dev;
+ int r = 0;

- return __blkdev_driver_ioctl(fc->dev->bdev, fc->dev->mode, cmd, arg);
+ /*
+ * Only pass ioctls through if the device sizes match exactly.
+ */
+ if (fc->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 flakey_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
--- 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
@@ -1520,6 +1520,12 @@ 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);
}



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