From: Kevin Corry Date: Fri, 17 Mar 2006 07:04:03 +0000 (-0800) Subject: [PATCH] dm stripe: Fix bounds X-Git-Tag: v2.6.16~13 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8ba32fde2c5be52865b2fd7e5e3752a46971fabe;p=pandora-kernel.git [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 Signed-off-by: Alasdair G Kergon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed