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.
Cc: <stable@kernel.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.de>
mddev_t *mddev = q->queuedata;
int rv;
int cpu;
mddev_t *mddev = q->queuedata;
int rv;
int cpu;
if (mddev == NULL || mddev->pers == NULL
|| !mddev->ready) {
if (mddev == NULL || mddev->pers == NULL
|| !mddev->ready) {
atomic_inc(&mddev->active_io);
rcu_read_unlock();
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]);
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)
part_stat_unlock();
if (atomic_dec_and_test(&mddev->active_io) && mddev->suspended)