diff options
| -rw-r--r-- | drivers/md/raid0.c | 107 |
1 files changed, 77 insertions, 30 deletions
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index 39936a217f9..7cd2671cc79 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -273,7 +273,12 @@ static int raid0_mergeable_bvec(struct request_queue *q, unsigned int chunk_sectors = mddev->chunk_size >> 9; unsigned int bio_sectors = bvm->bi_size >> 9; - max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; + if (is_power_of_2(mddev->chunk_size)) + max = (chunk_sectors - ((sector & (chunk_sectors-1)) + + bio_sectors)) << 9; + else + max = (chunk_sectors - (sector_div(sector, chunk_sectors) + + bio_sectors)) << 9; if (max < 0) max = 0; /* bio_add cannot handle a negative return */ if (max <= biovec->bv_len && bio_sectors == 0) return biovec->bv_len; @@ -299,9 +304,8 @@ static int raid0_run(mddev_t *mddev) { int ret; - if (mddev->chunk_size == 0 || - !is_power_of_2(mddev->chunk_size)) { - printk(KERN_ERR "md/raid0: chunk size must be a power of 2.\n"); + if (mddev->chunk_size == 0) { + printk(KERN_ERR "md/raid0: chunk size must be set.\n"); return -EINVAL; } blk_queue_max_sectors(mddev->queue, mddev->chunk_size >> 9); @@ -367,15 +371,65 @@ static struct strip_zone *find_zone(struct raid0_private_data *conf, BUG(); } -static int raid0_make_request (struct request_queue *q, struct bio *bio) +/* + * remaps the bio to the target device. we separate two flows. + * power 2 flow and a general flow for the sake of perfromance +*/ +static mdk_rdev_t *map_sector(mddev_t *mddev, struct strip_zone *zone, + sector_t sector, sector_t *sector_offset) { - mddev_t *mddev = q->queuedata; - unsigned int sect_in_chunk, chunksect_bits, chunk_sects; + unsigned int sect_in_chunk; + sector_t chunk; raid0_conf_t *conf = mddev->private; + unsigned int chunk_sects = mddev->chunk_size >> 9; + + if (is_power_of_2(mddev->chunk_size)) { + int chunksect_bits = ffz(~chunk_sects); + /* find the sector offset inside the chunk */ + sect_in_chunk = sector & (chunk_sects - 1); + sector >>= chunksect_bits; + /* chunk in zone */ + chunk = *sector_offset; + /* quotient is the chunk in real device*/ + sector_div(chunk, zone->nb_dev << chunksect_bits); + } else{ + sect_in_chunk = sector_div(sector, chunk_sects); + chunk = *sector_offset; + sector_div(chunk, chunk_sects * zone->nb_dev); + } + /* + * position the bio over the real device + * real sector = chunk in device + starting of zone + * + the position in the chunk + */ + *sector_offset = (chunk * chunk_sects) + sect_in_chunk; + return conf->devlist[(zone - conf->strip_zone)*mddev->raid_disks + + sector_div(sector, zone->nb_dev)]; +} + +/* + * Is io distribute over 1 or more chunks ? +*/ +static inline int is_io_in_chunk_boundary(mddev_t *mddev, + unsigned int chunk_sects, struct bio *bio) +{ + if (likely(is_power_of_2(mddev->chunk_size))) { + return chunk_sects >= ((bio->bi_sector & (chunk_sects-1)) + + (bio->bi_size >> 9)); + } else{ + sector_t sector = bio->bi_sector; + return chunk_sects >= (sector_div(sector, chunk_sects) + + (bio->bi_size >> 9)); + } +} + +static int raid0_make_request(struct request_queue *q, struct bio *bio) +{ + mddev_t *mddev = q->queuedata; + unsigned int chunk_sects; + sector_t sector_offset; struct strip_zone *zone; mdk_rdev_t *tmp_dev; - sector_t chunk; - sector_t sector, rsect, sector_offset; const int rw = bio_data_dir(bio); int cpu; @@ -391,10 +445,8 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio) part_stat_unlock(); chunk_sects = mddev->chunk_size >> 9; - chunksect_bits = ffz(~chunk_sects); - sector = bio->bi_sector; - - if (unlikely(chunk_sects < (bio->bi_sector & (chunk_sects - 1)) + (bio->bi_size >> 9))) { + if (unlikely(!is_io_in_chunk_boundary(mddev, chunk_sects, bio))) { + sector_t sector = bio->bi_sector; struct bio_pair *bp; /* Sanity check -- queue functions should prevent this happening */ if (bio->bi_vcnt != 1 || @@ -403,7 +455,12 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio) /* This is a one page bio that upper layers * refuse to split for us, so we need to split it. */ - bp = bio_split(bio, chunk_sects - (bio->bi_sector & (chunk_sects - 1))); + if (likely(is_power_of_2(mddev->chunk_size))) + bp = bio_split(bio, chunk_sects - (sector & + (chunk_sects-1))); + else + bp = bio_split(bio, chunk_sects - + sector_div(sector, chunk_sects)); if (raid0_make_request(q, &bp->bio1)) generic_make_request(&bp->bio1); if (raid0_make_request(q, &bp->bio2)) @@ -412,24 +469,14 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio) bio_pair_release(bp); return 0; } - sector_offset = sector; - zone = find_zone(conf, §or_offset); - sect_in_chunk = bio->bi_sector & (chunk_sects - 1); - { - sector_t x = sector_offset >> chunksect_bits; - - sector_div(x, zone->nb_dev); - chunk = x; - x = sector >> chunksect_bits; - tmp_dev = conf->devlist[(zone - conf->strip_zone)*mddev->raid_disks - + sector_div(x, zone->nb_dev)]; - } - rsect = (chunk << chunksect_bits) + zone->dev_start + sect_in_chunk; - + sector_offset = bio->bi_sector; + zone = find_zone(mddev->private, §or_offset); + tmp_dev = map_sector(mddev, zone, bio->bi_sector, + §or_offset); bio->bi_bdev = tmp_dev->bdev; - bio->bi_sector = rsect + tmp_dev->data_offset; - + bio->bi_sector = sector_offset + zone->dev_start + + tmp_dev->data_offset; /* * Let the main block layer submit the IO and resolve recursion: */ |