lkml.org 
[lkml]   [2008]   [May]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 001 of 10] 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 <neilb@suse.de>

### Diffstat output
./drivers/md/raid1.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff .prev/drivers/md/raid1.c ./drivers/md/raid1.c
--- .prev/drivers/md/raid1.c 2008-05-19 11:02:04.000000000 +1000
+++ ./drivers/md/raid1.c 2008-05-19 11:02:15.000000000 +1000
@@ -773,7 +773,7 @@ static int make_request(struct request_q
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_q

wait_barrier(conf);

+ bitmap = mddev->bitmap;
+
disk_stat_inc(mddev->gendisk, ios[rw]);
disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));


\
 
 \ /
  Last update: 2008-05-19 03:15    [from the cache]
©2003-2011 Jasper Spaans. Advertise on this site