diff options
| author | Kevin Corry <kevcorry@us.ibm.com> | 2006-03-16 23:04:03 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-17 07:51:25 -0800 |
| commit | 8ba32fde2c5be52865b2fd7e5e3752a46971fabe (patch) | |
| tree | 91988d69b76b1d142117b0ed827fc20eb11c9360 | |
| parent | 82c3c03a4096badd026c6e337f3c5dde020e9ec6 (diff) | |
[PATCH] dm stripe: Fix bounds
The dm-stripe target currently does not enforce that the size of a stripe
device be a multiple of the chunk-size. Under certain conditions, this can
lead to I/O requests going off the end of an underlying device. This
test-case shows one example.
echo "0 100 linear /dev/hdb1 0" | dmsetup create linear0
echo "0 100 linear /dev/hdb1 100" | dmsetup create linear1
echo "0 200 striped 2 32 /dev/mapper/linear0 0 /dev/mapper/linear1 0" | \
dmsetup create stripe0
dd if=/dev/zero of=/dev/mapper/stripe0 bs=1k
This will produce the output:
dd: writing '/dev/mapper/stripe0': Input/output error
97+0 records in
96+0 records out
And in the kernel log will be:
attempt to access beyond end of device
dm-0: rw=0, want=104, limit=100
The patch will check that the table size is a multiple of the stripe
chunk-size when the table is created, which will prevent the above striped
device from being created.
This should not affect tools like LVM or EVMS, since in all the cases I can
think of, striped devices are always created with the sizes being a
multiple of the chunk-size.
The size of a stripe device must be a multiple of its chunk-size.
(akpm: that typecast is quite gratuitous)
Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | drivers/md/dm-stripe.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index ab89278a56bf..697aacafb02a 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -103,9 +103,15 @@ static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv) return -EINVAL; } + if (((uint32_t)ti->len) & (chunk_size - 1)) { + ti->error = "dm-stripe: Target length not divisible by " + "chunk size"; + return -EINVAL; + } + width = ti->len; if (sector_div(width, stripes)) { - ti->error = "dm-stripe: Target length not divisable by " + ti->error = "dm-stripe: Target length not divisible by " "number of stripes"; return -EINVAL; } |