From 64590f45ddc7147fa1968147a1f5b5c436b728fe Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 15 Dec 2014 12:56:57 +1100 Subject: md: make merge_bvec_fn more robust in face of personality changes. There is no locking around calls to merge_bvec_fn(), so it is possible that calls which coincide with a level (or personality) change could go wrong. So create a central dispatch point for these functions and use rcu_read_lock(). If the array is suspended, reject any merge that can be rejected. If not, we know it is safe to call the function. Signed-off-by: NeilBrown --- drivers/md/raid0.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'drivers/md/raid0.c') diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 4b521ea..3770c96 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -350,17 +350,16 @@ static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, /** * raid0_mergeable_bvec -- tell bio layer if two requests can be merged - * @q: request queue + * @mddev: the md device * @bvm: properties of new bio * @biovec: the request that could be merged to it. * * Return amount of bytes we can accept at this offset */ -static int raid0_mergeable_bvec(struct request_queue *q, +static int raid0_mergeable_bvec(struct mddev *mddev, struct bvec_merge_data *bvm, struct bio_vec *biovec) { - struct mddev *mddev = q->queuedata; struct r0conf *conf = mddev->private; sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); sector_t sector_offset = sector; @@ -465,7 +464,6 @@ static int raid0_run(struct mddev *mddev) mddev->queue->backing_dev_info.ra_pages = 2* stripe; } - blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); dump_zones(mddev); ret = md_integrity_register(mddev); @@ -724,6 +722,7 @@ static struct md_personality raid0_personality= .takeover = raid0_takeover, .quiesce = raid0_quiesce, .congested = raid0_congested, + .mergeable_bvec = raid0_mergeable_bvec, }; static int __init raid0_init (void) -- cgit v1.1