From ec8013beddd717d1740cfefb1a9b900deef85462 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 12 Jan 2012 16:01:29 +0100
Subject: [PATCH] dm: do not forward ioctls from logical volumes to the
underlying device
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>
---
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 f84c08029b2154..9fb18c147825ae 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 3921e3bb43c15a..9728839f844a8b 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 5e0090ef4182e7..801d92d237cfc3 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);
}
--
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