* Re: [dm-devel] [PATCH stable 3/3] dm: do not forward ioctls from logical volumes to the underlying device
2012-01-16 16:13 ` [PATCH stable 3/3] dm: do not forward ioctls from logical volumes to the underlying device Paolo Bonzini
@ 2012-01-17 0:32 ` Mikulas Patocka
0 siblings, 0 replies; 2+ messages in thread
From: Mikulas Patocka @ 2012-01-17 0:32 UTC (permalink / raw)
To: Paolo Bonzini
Cc: linux-kernel, dm-devel, Linus Torvalds, stable, Alasdair G Kergon,
linux-scsi
Hi
You should put this test to a function or macro. Don't copy the same logic
to three different places. Think what happens if someone needs to change
it after few years --- it will be hard to find out what was copied where.
Mikulas
On Mon, 16 Jan 2012, Paolo Bonzini wrote:
> 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.
>
> [ Cherry picked from 95113a17a2a1eb06151dc698dca9bcc4a29e4fbb ]
>
> Cc: stable@kernel.org
> Cc: Alasdair G Kergon <agk@redhat.com>
> Cc: dm-devel@redhat.com
> Cc: linux-scsi@vger.kernel.org
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> ---
> 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(-)
>
> diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
> index f84c080..9fb18c1 100644
> --- a/drivers/md/dm-flakey.c
> +++ b/drivers/md/dm-flakey.c
> @@ -368,8 +368,17 @@ static int flakey_status(struct dm_target *ti, status_type_t type,
> 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,
> diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
> index 3921e3b..9728839 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 5e0090e..801d92d 100644
> --- a/drivers/md/dm-mpath.c
> +++ b/drivers/md/dm-mpath.c
> @@ -1520,6 +1520,12 @@ 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);
> }
>
> --
> 1.7.7.1
>
> --
> dm-devel mailing list
> dm-devel@redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>
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