/* 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 "md.h"#include "raid0.h"#include "raid5.h" static int raid0_congested(void *data, int bits){ struct mddev *mddev = data; struct r0conf *conf = mddev->private; struct md_rdev **devlist = conf->devlist; int raid_disks = conf->strip_zone[0].nb_dev; int i, ret = 0; if (mddev_congested(mddev, bits)) return 1; 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; printk(KERN_INFO "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++) { printk(KERN_INFO "md: zone%d=[", j); for (k = 0; k < conf->strip_zone[j].nb_dev; k++) printk(KERN_CONT "%s%s", k?"/":"", bdevname(conf->devlist[j*raid_disks + k]->bdev, b)); printk(KERN_CONT "]\n"); zone_size = conf->strip_zone[j].zone_end - zone_start; printk(KERN_INFO " 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; } printk(KERN_INFO "\n");} 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); bool discard_supported = false; 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; 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); 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) { printk(KERN_ERR "md/raid0:%s: remove inactive devices before converting to RAID0\n", mdname(mddev)); goto abort; } if (j >= mddev->raid_disks) { printk(KERN_ERR "md/raid0:%s: bad disk number %d - " "aborting!\n", mdname(mddev), j); goto abort; } if (dev[j]) { printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " "aborting!\n", mdname(mddev), j); goto abort; } dev[j] = rdev1; disk_stack_limits(mddev->gendisk, rdev1->bdev, rdev1->data_offset << 9); if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) conf->has_merge_bvec = 1; if (!smallest || (rdev1->sectors < smallest->sectors)) smallest = rdev1; cnt++; if (blk_queue_discard(bdev_get_queue(rdev1->bdev))) discard_supported = true; } if (cnt != mddev->raid_disks) { printk(KERN_ERR "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); } mddev->queue->backing_dev_info.congested_fn = raid0_congested; mddev->queue->backing_dev_info.congested_data = mddev; /* * 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) % queue_logical_block_size(mddev->queue)) { printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", mdname(mddev), mddev->chunk_sectors << 9); goto abort; } blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); blk_queue_io_opt(mddev->queue, (mddev->chunk_sectors << 9) * mddev->raid_disks); if (!discard_supported) queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 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 perfromance*/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)];} /** * raid0_mergeable_bvec -- tell bio layer if two requests can be merged * @q: request queue * @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, 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; int max; unsigned int chunk_sectors = mddev->chunk_sectors; unsigned int bio_sectors = bvm->bi_size >> 9; struct strip_zone *zone; struct md_rdev *rdev; struct request_queue *subq; if (is_power_of_2(chunk_sectors)) 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; if (max < biovec->bv_len) /* too small already, no need to check further */ return max; if (!conf->has_merge_bvec) return max; /* May need to check subordinate device */ sector = sector_offset; zone = find_zone(mddev->private, §or_offset); rdev = map_sector(mddev, zone, sector, §or_offset); subq = bdev_get_queue(rdev->bdev); if (subq->merge_bvec_fn) { bvm->bi_bdev = rdev->bdev; bvm->bi_sector = sector_offset + zone->dev_start + rdev->data_offset; return min(max, subq->merge_bvec_fn(subq, bvm, biovec)); } else return max;} 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 int raid0_stop(struct mddev *mddev); static int raid0_run(struct mddev *mddev){ struct r0conf *conf; int ret; if (mddev->chunk_sectors == 0) { printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", mdname(mddev)); return -EINVAL; } if (md_check_no_bitmap(mddev)) return -EINVAL; blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); /* 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; /* calculate array device size */ md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", mdname(mddev), (unsigned long long)mddev->array_sectors); /* 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; } blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); dump_zones(mddev); ret = md_integrity_register(mddev); if (ret) raid0_stop(mddev); return ret;} static int raid0_stop(struct mddev *mddev){ struct r0conf *conf = mddev->private; blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ kfree(conf->strip_zone); kfree(conf->devlist); kfree(conf); mddev->private = NULL; return 0;} /* * Is io distribute over 1 or more chunks ?*/static inline int is_io_in_chunk_boundary(struct mddev *mddev,Lines 1–500 of 764. Load more
/* 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 "md.h" #include "raid0.h" #include "raid5.h" static int raid0_congested(void *data, int bits) { struct mddev *mddev = data; struct r0conf *conf = mddev->private; struct md_rdev **devlist = conf->devlist; int raid_disks = conf->strip_zone[0].nb_dev; int i, ret = 0; if (mddev_congested(mddev, bits)) return 1; 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; printk(KERN_INFO "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++) { printk(KERN_INFO "md: zone%d=[", j); for (k = 0; k < conf->strip_zone[j].nb_dev; k++) printk(KERN_CONT "%s%s", k?"/":"", bdevname(conf->devlist[j*raid_disks + k]->bdev, b)); printk(KERN_CONT "]\n"); zone_size = conf->strip_zone[j].zone_end - zone_start; printk(KERN_INFO " 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; } printk(KERN_INFO "\n"); } 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); bool discard_supported = false; 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; 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); 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) { printk(KERN_ERR "md/raid0:%s: remove inactive devices before converting to RAID0\n", mdname(mddev)); goto abort; } if (j >= mddev->raid_disks) { printk(KERN_ERR "md/raid0:%s: bad disk number %d - " "aborting!\n", mdname(mddev), j); goto abort; } if (dev[j]) { printk(KERN_ERR "md/raid0:%s: multiple devices for %d - " "aborting!\n", mdname(mddev), j); goto abort; } dev[j] = rdev1; disk_stack_limits(mddev->gendisk, rdev1->bdev, rdev1->data_offset << 9); if (rdev1->bdev->bd_disk->queue->merge_bvec_fn) conf->has_merge_bvec = 1; if (!smallest || (rdev1->sectors < smallest->sectors)) smallest = rdev1; cnt++; if (blk_queue_discard(bdev_get_queue(rdev1->bdev))) discard_supported = true; } if (cnt != mddev->raid_disks) { printk(KERN_ERR "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); } mddev->queue->backing_dev_info.congested_fn = raid0_congested; mddev->queue->backing_dev_info.congested_data = mddev; /* * 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) % queue_logical_block_size(mddev->queue)) { printk(KERN_ERR "md/raid0:%s: chunk_size of %d not valid\n", mdname(mddev), mddev->chunk_sectors << 9); goto abort; } blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); blk_queue_io_opt(mddev->queue, (mddev->chunk_sectors << 9) * mddev->raid_disks); if (!discard_supported) queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); else queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); 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 perfromance */ 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)]; } /** * raid0_mergeable_bvec -- tell bio layer if two requests can be merged * @q: request queue * @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, 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; int max; unsigned int chunk_sectors = mddev->chunk_sectors; unsigned int bio_sectors = bvm->bi_size >> 9; struct strip_zone *zone; struct md_rdev *rdev; struct request_queue *subq; if (is_power_of_2(chunk_sectors)) 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; if (max < biovec->bv_len) /* too small already, no need to check further */ return max; if (!conf->has_merge_bvec) return max; /* May need to check subordinate device */ sector = sector_offset; zone = find_zone(mddev->private, §or_offset); rdev = map_sector(mddev, zone, sector, §or_offset); subq = bdev_get_queue(rdev->bdev); if (subq->merge_bvec_fn) { bvm->bi_bdev = rdev->bdev; bvm->bi_sector = sector_offset + zone->dev_start + rdev->data_offset; return min(max, subq->merge_bvec_fn(subq, bvm, biovec)); } else return max; } 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 int raid0_stop(struct mddev *mddev); static int raid0_run(struct mddev *mddev) { struct r0conf *conf; int ret; if (mddev->chunk_sectors == 0) { printk(KERN_ERR "md/raid0:%s: chunk size must be set.\n", mdname(mddev)); return -EINVAL; } if (md_check_no_bitmap(mddev)) return -EINVAL; blk_queue_max_hw_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_write_same_sectors(mddev->queue, mddev->chunk_sectors); blk_queue_max_discard_sectors(mddev->queue, mddev->chunk_sectors); /* 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; /* calculate array device size */ md_set_array_sectors(mddev, raid0_size(mddev, 0, 0)); printk(KERN_INFO "md/raid0:%s: md_size is %llu sectors.\n", mdname(mddev), (unsigned long long)mddev->array_sectors); /* 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; } blk_queue_merge_bvec(mddev->queue, raid0_mergeable_bvec); dump_zones(mddev); ret = md_integrity_register(mddev); if (ret) raid0_stop(mddev); return ret; } static int raid0_stop(struct mddev *mddev) { struct r0conf *conf = mddev->private; blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ kfree(conf->strip_zone); kfree(conf->devlist); kfree(conf); mddev->private = NULL; return 0; } /* * Is io distribute over 1 or more chunks ? */ static inline int is_io_in_chunk_boundary(struct mddev *mddev,