From: Alasdair G Kergon <agk@redhat.com>
Date: Fri, 8 Jul 2005 00:59:34 +0000 (-0700)
Subject: [PATCH] device-mapper: dm-raid1: Limit bios to size of mirror region
X-Git-Tag: v2.6.13-rc3~114
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d88854f08961d26f3a63cfae7972188d26a128e4;p=linux-2.6

[PATCH] device-mapper: dm-raid1: Limit bios to size of mirror region

Set the target's split_io field when building a dm-mirror device so
incoming bios won't span the mirror's internal regions.  Without this,
regions can be accessed while not holding correct locks and data corruption
is possible.

Reported-By: "Zhao Qian" <zhaoqian@aaastor.com>
From: 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>
---

diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 6e3cf7e134..12031c9d3f 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -1060,6 +1060,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	}
 
 	ti->private = ms;
+ 	ti->split_io = ms->rh.region_size;
 
 	r = kcopyd_client_create(DM_IO_PAGES, &ms->kcopyd_client);
 	if (r) {