This makes md raid 10 support TRIM. If one disk supports discard and another not, or one has discard_zero_data and another not, there could be inconsistent between data from such disks. But this should not matter, discarded data is useless. This will add extra copy in rebuild though. Signed-off-by: Shaohua Li --- drivers/md/raid10.c | 26 +++++++++++++++++++++++--- 1 file changed, 23 insertions(+), 3 deletions(-) Index: linux/drivers/md/raid10.c =================================================================== --- linux.orig/drivers/md/raid10.c 2012-03-12 10:09:42.426612652 +0800 +++ linux/drivers/md/raid10.c 2012-03-12 10:19:05.046610195 +0800 @@ -800,7 +800,12 @@ static void flush_pending_writes(struct while (bio) { /* submit pending writes */ struct bio *next = bio->bi_next; bio->bi_next = NULL; - generic_make_request(bio); + if (unlikely((bio->bi_rw & REQ_DISCARD) && + !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) + /* Just ignore it */ + bio_endio(bio, 0); + else + generic_make_request(bio); bio = next; } } else @@ -926,6 +931,7 @@ static void make_request(struct mddev *m const int rw = bio_data_dir(bio); const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); const unsigned long do_fua = (bio->bi_rw & REQ_FUA); + const unsigned long do_discard = (bio->bi_rw & (REQ_DISCARD | REQ_SECURE)); unsigned long flags; struct md_rdev *blocked_rdev; int plugged; @@ -1241,7 +1247,7 @@ retry_write: conf->mirrors[d].rdev->data_offset); mbio->bi_bdev = conf->mirrors[d].rdev->bdev; mbio->bi_end_io = raid10_end_write_request; - mbio->bi_rw = WRITE | do_sync | do_fua; + mbio->bi_rw = WRITE | do_sync | do_fua | do_discard; mbio->bi_private = r10_bio; atomic_inc(&r10_bio->remaining); @@ -1266,7 +1272,7 @@ retry_write: conf->mirrors[d].replacement->data_offset); mbio->bi_bdev = conf->mirrors[d].replacement->bdev; mbio->bi_end_io = raid10_end_write_request; - mbio->bi_rw = WRITE | do_sync | do_fua; + mbio->bi_rw = WRITE | do_sync | do_fua | do_discard; mbio->bi_private = r10_bio; atomic_inc(&r10_bio->remaining); @@ -1543,6 +1549,9 @@ static int raid10_add_disk(struct mddev } md_integrity_add_rdev(rdev, mddev); + if (blk_queue_discard(bdev_get_queue(rdev->bdev))) + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); + print_conf(conf); return err; } @@ -3214,6 +3223,7 @@ static int run(struct mddev *mddev) struct mirror_info *disk; struct md_rdev *rdev; sector_t size; + bool discard_supported = false; /* * copy the already verified devices into our private RAID10 @@ -3234,6 +3244,7 @@ static int run(struct mddev *mddev) mddev->thread = conf->thread; conf->thread = NULL; + blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); chunk_size = mddev->chunk_sectors << 9; blk_queue_io_min(mddev->queue, chunk_size); if (conf->raid_disks % conf->near_copies) @@ -3273,7 +3284,16 @@ static int run(struct mddev *mddev) } disk->head_position = 0; + + if (blk_queue_discard(bdev_get_queue(rdev->bdev))) + discard_supported = true; } + + if (discard_supported) + queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); + else + queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); + /* need to check that every block has at least one working mirror */ if (!enough(conf, -1)) { printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n", -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/