diff options
| author | Chris Mason <chris.mason@oracle.com> | 2011-02-07 19:21:48 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-02-17 14:47:24 -0800 |
| commit | 823c5c79a5da97b6f4314be7d0f350fdc19df9b7 (patch) | |
| tree | d65ebc14c798434bf2d7ecedfebd82b3a4c40346 | |
| parent | 4f8fa9bc7226ba1581e63e3ff1b583f5c1026edd (diff) | |
md_make_request: don't touch the bio after calling make_request
commit e91ece5590b3c728624ab57043fc7a05069c604a upstream.
md_make_request was calling bio_sectors() for part_stat_add
after it was calling the make_request function. This is
bad because the make_request function can free the bio and
because the bi_size field can change around.
The fix here was suggested by Jens Axboe. It saves the
sector count before the make_request call. I hit this
with CONFIG_DEBUG_PAGEALLOC turned on while trying to break
his pretty fusionio card.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/md/md.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index e8de9083ccd6..012859708a1b 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -220,6 +220,7 @@ static int md_make_request(struct request_queue *q, struct bio *bio) mddev_t *mddev = q->queuedata; int rv; int cpu; + unsigned int sectors; if (mddev == NULL || mddev->pers == NULL || !mddev->ready) { @@ -244,12 +245,16 @@ static int md_make_request(struct request_queue *q, struct bio *bio) atomic_inc(&mddev->active_io); rcu_read_unlock(); + /* + * save the sectors now since our bio can + * go away inside make_request + */ + sectors = bio_sectors(bio); rv = mddev->pers->make_request(mddev, bio); cpu = part_stat_lock(); part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]); - part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], - bio_sectors(bio)); + part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw], sectors); part_stat_unlock(); if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended) |