From: NeilBrown Date: Fri, 23 May 2008 20:04:32 +0000 (-0700) Subject: md: fix possible oops when removing a bitmap from an active array X-Git-Tag: v2.6.26-rc4~43 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=84255d1018c50e72c71a49f359989597d53a3f53;p=linux-2.6-omap-h63xx.git md: fix possible oops when removing a bitmap from an active array It is possible to add a write-intent bitmap to an active array, or remove the bitmap that is there. When we do with the 'quiesce' the array, which causes make_request to block in "wait_barrier()". However we are sampling the value of "mddev->bitmap" before the wait_barrier call, and using it afterwards. This can result in using a bitmap structure that has been freed. Signed-off-by: Neil Brown Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index ac409b7d83f..21629ae4668 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -773,7 +773,7 @@ static int make_request(struct request_queue *q, struct bio * bio) r1bio_t *r1_bio; struct bio *read_bio; int i, targets = 0, disks; - struct bitmap *bitmap = mddev->bitmap; + struct bitmap *bitmap; unsigned long flags; struct bio_list bl; struct page **behind_pages = NULL; @@ -802,6 +802,8 @@ static int make_request(struct request_queue *q, struct bio * bio) wait_barrier(conf); + bitmap = mddev->bitmap; + disk_stat_inc(mddev->gendisk, ios[rw]); disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));