/* raid0.c : Multiple Devices driver for Linux Copyright (C) 1994-96 Marc ZYNGIER <zyngier@ufr-info-p7.ibp.fr> or <maz@gloups.fdn.fr> Copyright (C) 1999, 2000 Ingo Molnar, Red Hat RAID-0 management functions. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. You should have received a copy of the GNU General Public License (for example /usr/src/linux/COPYING); if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.*/ #include <linux/blkdev.h>#include <linux/seq_file.h>#include <linux/module.h>#include <linux/slab.h>#include <trace/events/block.h>#include "md.h"#include "raid0.h"#include "raid5.h" #define UNSUPPORTED_MDDEV_FLAGS \ ((1L << MD_HAS_JOURNAL) | \ (1L << MD_JOURNAL_CLEAN) | \ (1L << MD_FAILFAST_SUPPORTED) |\ (1L << MD_HAS_PPL)) static int raid0_congested(struct mddev *mddev, int bits){ struct r0conf *conf = mddev->private; struct md_rdev **devlist = conf->devlist; int raid_disks = conf->strip_zone[0].nb_dev; int i, ret = 0; for (i = 0; i < raid_disks && !ret ; i++) { struct request_queue *q = bdev_get_queue(devlist[i]->bdev); ret |= bdi_congested(q->backing_dev_info, bits); } return ret;} /* * inform the user of the raid configuration*/static void dump_zones(struct mddev *mddev){ int j, k; sector_t zone_size = 0; sector_t zone_start = 0; char b[BDEVNAME_SIZE]; struct r0conf *conf = mddev->private; int raid_disks = conf->strip_zone[0].nb_dev; pr_debug("md: RAID0 configuration for %s - %d zone%s\n", mdname(mddev), conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); for (j = 0; j < conf->nr_strip_zones; j++) { char line[200]; int len = 0; for (k = 0; k < conf->strip_zone[j].nb_dev; k++) len += snprintf(line+len, 200-len, "%s%s", k?"/":"", bdevname(conf->devlist[j*raid_disks + k]->bdev, b)); pr_debug("md: zone%d=[%s]\n", j, line); zone_size = conf->strip_zone[j].zone_end - zone_start; pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n", (unsigned long long)zone_start>>1, (unsigned long long)conf->strip_zone[j].dev_start>>1, (unsigned long long)zone_size>>1); zone_start = conf->strip_zone[j].zone_end; }} static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf){ int i, c, err; sector_t curr_zone_end, sectors; struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; struct strip_zone *zone; int cnt; char b[BDEVNAME_SIZE]; char b2[BDEVNAME_SIZE]; struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); unsigned short blksize = 512; *private_conf = ERR_PTR(-ENOMEM); if (!conf) return -ENOMEM; rdev_for_each(rdev1, mddev) { pr_debug("md/raid0:%s: looking at %s\n", mdname(mddev), bdevname(rdev1->bdev, b)); c = 0; /* round size to chunk_size */ sectors = rdev1->sectors; sector_div(sectors, mddev->chunk_sectors); rdev1->sectors = sectors * mddev->chunk_sectors; blksize = max(blksize, queue_logical_block_size( rdev1->bdev->bd_disk->queue)); rdev_for_each(rdev2, mddev) { pr_debug("md/raid0:%s: comparing %s(%llu)" " with %s(%llu)\n", mdname(mddev), bdevname(rdev1->bdev,b), (unsigned long long)rdev1->sectors, bdevname(rdev2->bdev,b2), (unsigned long long)rdev2->sectors); if (rdev2 == rdev1) { pr_debug("md/raid0:%s: END\n", mdname(mddev)); break; } if (rdev2->sectors == rdev1->sectors) { /* * Not unique, don't count it as a new * group */ pr_debug("md/raid0:%s: EQUAL\n", mdname(mddev)); c = 1; break; } pr_debug("md/raid0:%s: NOT EQUAL\n", mdname(mddev)); } if (!c) { pr_debug("md/raid0:%s: ==> UNIQUE\n", mdname(mddev)); conf->nr_strip_zones++; pr_debug("md/raid0:%s: %d zones\n", mdname(mddev), conf->nr_strip_zones); } } pr_debug("md/raid0:%s: FINAL %d zones\n", mdname(mddev), conf->nr_strip_zones); /* * now since we have the hard sector sizes, we can make sure * chunk size is a multiple of that sector size */ if ((mddev->chunk_sectors << 9) % blksize) { pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", mdname(mddev), mddev->chunk_sectors << 9, blksize); err = -EINVAL; goto abort; } err = -ENOMEM; conf->strip_zone = kzalloc(sizeof(struct strip_zone)* conf->nr_strip_zones, GFP_KERNEL); if (!conf->strip_zone) goto abort; conf->devlist = kzalloc(sizeof(struct md_rdev*)* conf->nr_strip_zones*mddev->raid_disks, GFP_KERNEL); if (!conf->devlist) goto abort; /* The first zone must contain all devices, so here we check that * there is a proper alignment of slots to devices and find them all */ zone = &conf->strip_zone[0]; cnt = 0; smallest = NULL; dev = conf->devlist; err = -EINVAL; rdev_for_each(rdev1, mddev) { int j = rdev1->raid_disk; if (mddev->level == 10) { /* taking over a raid10-n2 array */ j /= 2; rdev1->new_raid_disk = j; } if (mddev->level == 1) { /* taiking over a raid1 array- * we have only one active disk */ j = 0; rdev1->new_raid_disk = j; } if (j < 0) { pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", mdname(mddev)); goto abort; } if (j >= mddev->raid_disks) { pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", mdname(mddev), j); goto abort; } if (dev[j]) { pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", mdname(mddev), j); goto abort; } dev[j] = rdev1; if (!smallest || (rdev1->sectors < smallest->sectors)) smallest = rdev1; cnt++; } if (cnt != mddev->raid_disks) { pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", mdname(mddev), cnt, mddev->raid_disks); goto abort; } zone->nb_dev = cnt; zone->zone_end = smallest->sectors * cnt; curr_zone_end = zone->zone_end; /* now do the other zones */ for (i = 1; i < conf->nr_strip_zones; i++) { int j; zone = conf->strip_zone + i; dev = conf->devlist + i * mddev->raid_disks; pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); zone->dev_start = smallest->sectors; smallest = NULL; c = 0; for (j=0; j<cnt; j++) { rdev = conf->devlist[j]; if (rdev->sectors <= zone->dev_start) { pr_debug("md/raid0:%s: checking %s ... nope\n", mdname(mddev), bdevname(rdev->bdev, b)); continue; } pr_debug("md/raid0:%s: checking %s ..." " contained as device %d\n", mdname(mddev), bdevname(rdev->bdev, b), c); dev[c] = rdev; c++; if (!smallest || rdev->sectors < smallest->sectors) { smallest = rdev; pr_debug("md/raid0:%s: (%llu) is smallest!.\n", mdname(mddev), (unsigned long long)rdev->sectors); } } zone->nb_dev = c; sectors = (smallest->sectors - zone->dev_start) * c; pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", mdname(mddev), zone->nb_dev, (unsigned long long)sectors); curr_zone_end += sectors; zone->zone_end = curr_zone_end; pr_debug("md/raid0:%s: current zone start: %llu\n", mdname(mddev), (unsigned long long)smallest->sectors); } pr_debug("md/raid0:%s: done.\n", mdname(mddev)); *private_conf = conf; return 0;abort: kfree(conf->strip_zone); kfree(conf->devlist); kfree(conf); *private_conf = ERR_PTR(err); return err;} /* Find the zone which holds a particular offset * Update *sectorp to be an offset in that zone */static struct strip_zone *find_zone(struct r0conf *conf, sector_t *sectorp){ int i; struct strip_zone *z = conf->strip_zone; sector_t sector = *sectorp; for (i = 0; i < conf->nr_strip_zones; i++) if (sector < z[i].zone_end) { if (i) *sectorp = sector - z[i-1].zone_end; return z + i; } BUG();} /* * remaps the bio to the target device. we separate two flows. * power 2 flow and a general flow for the sake of performance*/static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, sector_t sector, sector_t *sector_offset){ unsigned int sect_in_chunk; sector_t chunk; struct r0conf *conf = mddev->private; int raid_disks = conf->strip_zone[0].nb_dev; unsigned int chunk_sects = mddev->chunk_sectors; if (is_power_of_2(chunk_sects)) { 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)*raid_disks + sector_div(sector, zone->nb_dev)];} static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks){ sector_t array_sectors = 0; struct md_rdev *rdev; WARN_ONCE(sectors || raid_disks, "%s does not support generic reshape\n", __func__); rdev_for_each(rdev, mddev) array_sectors += (rdev->sectors & ~(sector_t)(mddev->chunk_sectors-1)); return array_sectors;} static void raid0_free(struct mddev *mddev, void *priv); static int raid0_run(struct mddev *mddev){ struct r0conf *conf; int ret; if (mddev->chunk_sectors == 0) { pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); return -EINVAL; } if (md_check_no_bitmap(mddev)) return -EINVAL; /* if private is not null, we are here after takeover */ if (mddev->private == NULL) { ret = create_strip_zones(mddev, &conf); if (ret < 0) return ret; mddev->private = conf; } conf = mddev->private; if (mddev->queue) { struct md_rdev *rdev; bool discard_supported = false; blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_discard_sectors(mddev->queue, UINT_MAX); blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); blk_queue_io_opt(mddev->queue, (mddev->chunk_sectors << 9) * mddev->raid_disks); rdev_for_each(rdev, mddev) { disk_stack_limits(mddev->gendisk, rdev->bdev, rdev->data_offset << 9); if (blk_queue_discard(bdev_get_queue(rdev->bdev))) discard_supported = true; } if (!discard_supported) queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); } /* calculate array device size */ md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); pr_debug("md/raid0:%s: md_size is %llu sectors.\n", mdname(mddev), (unsigned long long)mddev->array_sectors); if (mddev->queue) { /* calculate the max read-ahead size. * For read-ahead of large files to be effective, we need to * readahead at least twice a whole stripe. i.e. number of devices * multiplied by chunk size times 2. * If an individual device has an ra_pages greater than the * chunk size, then we will not drive that device as hard as it * wants. We consider this a configuration error: a larger * chunksize should be used in that case. */ int stripe = mddev->raid_disks * (mddev->chunk_sectors << 9) / PAGE_SIZE; if (mddev->queue->backing_dev_info->ra_pages < 2* stripe) mddev->queue->backing_dev_info->ra_pages = 2* stripe; } dump_zones(mddev); ret = md_integrity_register(mddev); return ret;} static void raid0_free(struct mddev *mddev, void *priv){ struct r0conf *conf = priv; kfree(conf->strip_zone); kfree(conf->devlist); kfree(conf);} /* * Is io distribute over 1 or more chunks ?*/static inline int is_io_in_chunk_boundary(struct mddev *mddev, unsigned int chunk_sects, struct bio *bio){ if (likely(is_power_of_2(chunk_sects))) { return chunk_sects >= ((bio->bi_iter.bi_sector & (chunk_sects-1)) + bio_sectors(bio)); } else{ sector_t sector = bio->bi_iter.bi_sector; return chunk_sects >= (sector_div(sector, chunk_sects) + bio_sectors(bio)); }} static void raid0_handle_discard(struct mddev *mddev, struct bio *bio){ struct r0conf *conf = mddev->private; struct strip_zone *zone; sector_t start = bio->bi_iter.bi_sector; sector_t end; unsigned int stripe_size; sector_t first_stripe_index, last_stripe_index; sector_t start_disk_offset; unsigned int start_disk_index; sector_t end_disk_offset; unsigned int end_disk_index; unsigned int disk; zone = find_zone(conf, &start); if (bio_end_sector(bio) > zone->zone_end) { struct bio *split = bio_split(bio, zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO, mddev->bio_set); bio_chain(split, bio); generic_make_request(bio); bio = split; end = zone->zone_end; } else end = bio_end_sector(bio); if (zone != conf->strip_zone) end = end - zone[-1].zone_end; /* Now start and end is the offset in zone */ stripe_size = zone->nb_dev * mddev->chunk_sectors; first_stripe_index = start; sector_div(first_stripe_index, stripe_size); last_stripe_index = end; sector_div(last_stripe_index, stripe_size); start_disk_index = (int)(start - first_stripe_index * stripe_size) /Lines 1–500 of 805. 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/* raid0.c : Multiple Devices driver for Linux Copyright (C) 1994-96 Marc ZYNGIER <zyngier@ufr-info-p7.ibp.fr> or <maz@gloups.fdn.fr> Copyright (C) 1999, 2000 Ingo Molnar, Red Hat RAID-0 management functions. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. You should have received a copy of the GNU General Public License (for example /usr/src/linux/COPYING); if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/blkdev.h> #include <linux/seq_file.h> #include <linux/module.h> #include <linux/slab.h> #include <trace/events/block.h> #include "md.h" #include "raid0.h" #include "raid5.h" #define UNSUPPORTED_MDDEV_FLAGS \ ((1L << MD_HAS_JOURNAL) | \ (1L << MD_JOURNAL_CLEAN) | \ (1L << MD_FAILFAST_SUPPORTED) |\ (1L << MD_HAS_PPL)) static int raid0_congested(struct mddev *mddev, int bits) { struct r0conf *conf = mddev->private; struct md_rdev **devlist = conf->devlist; int raid_disks = conf->strip_zone[0].nb_dev; int i, ret = 0; for (i = 0; i < raid_disks && !ret ; i++) { struct request_queue *q = bdev_get_queue(devlist[i]->bdev); ret |= bdi_congested(q->backing_dev_info, bits); } return ret; } /* * inform the user of the raid configuration */ static void dump_zones(struct mddev *mddev) { int j, k; sector_t zone_size = 0; sector_t zone_start = 0; char b[BDEVNAME_SIZE]; struct r0conf *conf = mddev->private; int raid_disks = conf->strip_zone[0].nb_dev; pr_debug("md: RAID0 configuration for %s - %d zone%s\n", mdname(mddev), conf->nr_strip_zones, conf->nr_strip_zones==1?"":"s"); for (j = 0; j < conf->nr_strip_zones; j++) { char line[200]; int len = 0; for (k = 0; k < conf->strip_zone[j].nb_dev; k++) len += snprintf(line+len, 200-len, "%s%s", k?"/":"", bdevname(conf->devlist[j*raid_disks + k]->bdev, b)); pr_debug("md: zone%d=[%s]\n", j, line); zone_size = conf->strip_zone[j].zone_end - zone_start; pr_debug(" zone-offset=%10lluKB, device-offset=%10lluKB, size=%10lluKB\n", (unsigned long long)zone_start>>1, (unsigned long long)conf->strip_zone[j].dev_start>>1, (unsigned long long)zone_size>>1); zone_start = conf->strip_zone[j].zone_end; } } static int create_strip_zones(struct mddev *mddev, struct r0conf **private_conf) { int i, c, err; sector_t curr_zone_end, sectors; struct md_rdev *smallest, *rdev1, *rdev2, *rdev, **dev; struct strip_zone *zone; int cnt; char b[BDEVNAME_SIZE]; char b2[BDEVNAME_SIZE]; struct r0conf *conf = kzalloc(sizeof(*conf), GFP_KERNEL); unsigned short blksize = 512; *private_conf = ERR_PTR(-ENOMEM); if (!conf) return -ENOMEM; rdev_for_each(rdev1, mddev) { pr_debug("md/raid0:%s: looking at %s\n", mdname(mddev), bdevname(rdev1->bdev, b)); c = 0; /* round size to chunk_size */ sectors = rdev1->sectors; sector_div(sectors, mddev->chunk_sectors); rdev1->sectors = sectors * mddev->chunk_sectors; blksize = max(blksize, queue_logical_block_size( rdev1->bdev->bd_disk->queue)); rdev_for_each(rdev2, mddev) { pr_debug("md/raid0:%s: comparing %s(%llu)" " with %s(%llu)\n", mdname(mddev), bdevname(rdev1->bdev,b), (unsigned long long)rdev1->sectors, bdevname(rdev2->bdev,b2), (unsigned long long)rdev2->sectors); if (rdev2 == rdev1) { pr_debug("md/raid0:%s: END\n", mdname(mddev)); break; } if (rdev2->sectors == rdev1->sectors) { /* * Not unique, don't count it as a new * group */ pr_debug("md/raid0:%s: EQUAL\n", mdname(mddev)); c = 1; break; } pr_debug("md/raid0:%s: NOT EQUAL\n", mdname(mddev)); } if (!c) { pr_debug("md/raid0:%s: ==> UNIQUE\n", mdname(mddev)); conf->nr_strip_zones++; pr_debug("md/raid0:%s: %d zones\n", mdname(mddev), conf->nr_strip_zones); } } pr_debug("md/raid0:%s: FINAL %d zones\n", mdname(mddev), conf->nr_strip_zones); /* * now since we have the hard sector sizes, we can make sure * chunk size is a multiple of that sector size */ if ((mddev->chunk_sectors << 9) % blksize) { pr_warn("md/raid0:%s: chunk_size of %d not multiple of block size %d\n", mdname(mddev), mddev->chunk_sectors << 9, blksize); err = -EINVAL; goto abort; } err = -ENOMEM; conf->strip_zone = kzalloc(sizeof(struct strip_zone)* conf->nr_strip_zones, GFP_KERNEL); if (!conf->strip_zone) goto abort; conf->devlist = kzalloc(sizeof(struct md_rdev*)* conf->nr_strip_zones*mddev->raid_disks, GFP_KERNEL); if (!conf->devlist) goto abort; /* The first zone must contain all devices, so here we check that * there is a proper alignment of slots to devices and find them all */ zone = &conf->strip_zone[0]; cnt = 0; smallest = NULL; dev = conf->devlist; err = -EINVAL; rdev_for_each(rdev1, mddev) { int j = rdev1->raid_disk; if (mddev->level == 10) { /* taking over a raid10-n2 array */ j /= 2; rdev1->new_raid_disk = j; } if (mddev->level == 1) { /* taiking over a raid1 array- * we have only one active disk */ j = 0; rdev1->new_raid_disk = j; } if (j < 0) { pr_warn("md/raid0:%s: remove inactive devices before converting to RAID0\n", mdname(mddev)); goto abort; } if (j >= mddev->raid_disks) { pr_warn("md/raid0:%s: bad disk number %d - aborting!\n", mdname(mddev), j); goto abort; } if (dev[j]) { pr_warn("md/raid0:%s: multiple devices for %d - aborting!\n", mdname(mddev), j); goto abort; } dev[j] = rdev1; if (!smallest || (rdev1->sectors < smallest->sectors)) smallest = rdev1; cnt++; } if (cnt != mddev->raid_disks) { pr_warn("md/raid0:%s: too few disks (%d of %d) - aborting!\n", mdname(mddev), cnt, mddev->raid_disks); goto abort; } zone->nb_dev = cnt; zone->zone_end = smallest->sectors * cnt; curr_zone_end = zone->zone_end; /* now do the other zones */ for (i = 1; i < conf->nr_strip_zones; i++) { int j; zone = conf->strip_zone + i; dev = conf->devlist + i * mddev->raid_disks; pr_debug("md/raid0:%s: zone %d\n", mdname(mddev), i); zone->dev_start = smallest->sectors; smallest = NULL; c = 0; for (j=0; j<cnt; j++) { rdev = conf->devlist[j]; if (rdev->sectors <= zone->dev_start) { pr_debug("md/raid0:%s: checking %s ... nope\n", mdname(mddev), bdevname(rdev->bdev, b)); continue; } pr_debug("md/raid0:%s: checking %s ..." " contained as device %d\n", mdname(mddev), bdevname(rdev->bdev, b), c); dev[c] = rdev; c++; if (!smallest || rdev->sectors < smallest->sectors) { smallest = rdev; pr_debug("md/raid0:%s: (%llu) is smallest!.\n", mdname(mddev), (unsigned long long)rdev->sectors); } } zone->nb_dev = c; sectors = (smallest->sectors - zone->dev_start) * c; pr_debug("md/raid0:%s: zone->nb_dev: %d, sectors: %llu\n", mdname(mddev), zone->nb_dev, (unsigned long long)sectors); curr_zone_end += sectors; zone->zone_end = curr_zone_end; pr_debug("md/raid0:%s: current zone start: %llu\n", mdname(mddev), (unsigned long long)smallest->sectors); } pr_debug("md/raid0:%s: done.\n", mdname(mddev)); *private_conf = conf; return 0; abort: kfree(conf->strip_zone); kfree(conf->devlist); kfree(conf); *private_conf = ERR_PTR(err); return err; } /* Find the zone which holds a particular offset * Update *sectorp to be an offset in that zone */ static struct strip_zone *find_zone(struct r0conf *conf, sector_t *sectorp) { int i; struct strip_zone *z = conf->strip_zone; sector_t sector = *sectorp; for (i = 0; i < conf->nr_strip_zones; i++) if (sector < z[i].zone_end) { if (i) *sectorp = sector - z[i-1].zone_end; return z + i; } BUG(); } /* * remaps the bio to the target device. we separate two flows. * power 2 flow and a general flow for the sake of performance */ static struct md_rdev *map_sector(struct mddev *mddev, struct strip_zone *zone, sector_t sector, sector_t *sector_offset) { unsigned int sect_in_chunk; sector_t chunk; struct r0conf *conf = mddev->private; int raid_disks = conf->strip_zone[0].nb_dev; unsigned int chunk_sects = mddev->chunk_sectors; if (is_power_of_2(chunk_sects)) { 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)*raid_disks + sector_div(sector, zone->nb_dev)]; } static sector_t raid0_size(struct mddev *mddev, sector_t sectors, int raid_disks) { sector_t array_sectors = 0; struct md_rdev *rdev; WARN_ONCE(sectors || raid_disks, "%s does not support generic reshape\n", __func__); rdev_for_each(rdev, mddev) array_sectors += (rdev->sectors & ~(sector_t)(mddev->chunk_sectors-1)); return array_sectors; } static void raid0_free(struct mddev *mddev, void *priv); static int raid0_run(struct mddev *mddev) { struct r0conf *conf; int ret; if (mddev->chunk_sectors == 0) { pr_warn("md/raid0:%s: chunk size must be set.\n", mdname(mddev)); return -EINVAL; } if (md_check_no_bitmap(mddev)) return -EINVAL; /* if private is not null, we are here after takeover */ if (mddev->private == NULL) { ret = create_strip_zones(mddev, &conf); if (ret < 0) return ret; mddev->private = conf; } conf = mddev->private; if (mddev->queue) { struct md_rdev *rdev; bool discard_supported = false; blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_zeroes_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_discard_sectors(mddev->queue, UINT_MAX); blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); blk_queue_io_opt(mddev->queue, (mddev->chunk_sectors << 9) * mddev->raid_disks); rdev_for_each(rdev, mddev) { disk_stack_limits(mddev->gendisk, rdev->bdev, rdev->data_offset << 9); if (blk_queue_discard(bdev_get_queue(rdev->bdev))) discard_supported = true; } if (!discard_supported) queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); } /* calculate array device size */ md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); pr_debug("md/raid0:%s: md_size is %llu sectors.\n", mdname(mddev), (unsigned long long)mddev->array_sectors); if (mddev->queue) { /* calculate the max read-ahead size. * For read-ahead of large files to be effective, we need to * readahead at least twice a whole stripe. i.e. number of devices * multiplied by chunk size times 2. * If an individual device has an ra_pages greater than the * chunk size, then we will not drive that device as hard as it * wants. We consider this a configuration error: a larger * chunksize should be used in that case. */ int stripe = mddev->raid_disks * (mddev->chunk_sectors << 9) / PAGE_SIZE; if (mddev->queue->backing_dev_info->ra_pages < 2* stripe) mddev->queue->backing_dev_info->ra_pages = 2* stripe; } dump_zones(mddev); ret = md_integrity_register(mddev); return ret; } static void raid0_free(struct mddev *mddev, void *priv) { struct r0conf *conf = priv; kfree(conf->strip_zone); kfree(conf->devlist); kfree(conf); } /* * Is io distribute over 1 or more chunks ? */ static inline int is_io_in_chunk_boundary(struct mddev *mddev, unsigned int chunk_sects, struct bio *bio) { if (likely(is_power_of_2(chunk_sects))) { return chunk_sects >= ((bio->bi_iter.bi_sector & (chunk_sects-1)) + bio_sectors(bio)); } else{ sector_t sector = bio->bi_iter.bi_sector; return chunk_sects >= (sector_div(sector, chunk_sects) + bio_sectors(bio)); } } static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) { struct r0conf *conf = mddev->private; struct strip_zone *zone; sector_t start = bio->bi_iter.bi_sector; sector_t end; unsigned int stripe_size; sector_t first_stripe_index, last_stripe_index; sector_t start_disk_offset; unsigned int start_disk_index; sector_t end_disk_offset; unsigned int end_disk_index; unsigned int disk; zone = find_zone(conf, &start); if (bio_end_sector(bio) > zone->zone_end) { struct bio *split = bio_split(bio, zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO, mddev->bio_set); bio_chain(split, bio); generic_make_request(bio); bio = split; end = zone->zone_end; } else end = bio_end_sector(bio); if (zone != conf->strip_zone) end = end - zone[-1].zone_end; /* Now start and end is the offset in zone */ stripe_size = zone->nb_dev * mddev->chunk_sectors; first_stripe_index = start; sector_div(first_stripe_index, stripe_size); last_stripe_index = end; sector_div(last_stripe_index, stripe_size); start_disk_index = (int)(start - first_stripe_index * stripe_size) /