/* * raid1.c : Multiple Devices driver for Linux * * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat * * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman * * RAID-1 management functions. * * Better read-balancing code written by Mika Kuoppala , 2000 * * Fixes to reconstruction by Jakob Østergaard" * Various fixes by Neil Brown * * Changes by Peter T. Breuer 31/1/2003 to support * bitmapped intelligence in resync: * * - bitmap marked during normal i/o * - bitmap used to skip nondirty blocks during sync * * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology: * - persistent bitmap code * * 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 "dm-bio-list.h" #include #include #define DEBUG 0 #if DEBUG #define PRINTK(x...) printk(x) #else #define PRINTK(x...) #endif /* * Number of guaranteed r1bios in case of extreme VM load: */ #define NR_RAID1_BIOS 256 static mdk_personality_t raid1_personality; static void unplug_slaves(mddev_t *mddev); static void * r1bio_pool_alloc(unsigned int __nocast gfp_flags, void *data) { struct pool_info *pi = data; r1bio_t *r1_bio; int size = offsetof(r1bio_t, bios[pi->raid_disks]); /* allocate a r1bio with room for raid_disks entries in the bios array */ r1_bio = kmalloc(size, gfp_flags); if (r1_bio) memset(r1_bio, 0, size); else unplug_slaves(pi->mddev); return r1_bio; } static void r1bio_pool_free(void *r1_bio, void *data) { kfree(r1_bio); } #define RESYNC_BLOCK_SIZE (64*1024) //#define RESYNC_BLOCK_SIZE PAGE_SIZE #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) #define RESYNC_WINDOW (2048*1024) static void * r1buf_pool_alloc(unsigned int __nocast gfp_flags, void *data) { struct pool_info *pi = data; struct page *page; r1bio_t *r1_bio; struct bio *bio; int i, j; r1_bio = r1bio_pool_alloc(gfp_flags, pi); if (!r1_bio) { unplug_slaves(pi->mddev); return NULL; } /* * Allocate bios : 1 for reading, n-1 for writing */ for (j = pi->raid_disks ; j-- ; ) { bio = bio_alloc(gfp_flags, RESYNC_PAGES); if (!bio) goto out_free_bio; r1_bio->bios[j] = bio; } /* * Allocate RESYNC_PAGES data pages and attach them to * the first bio; */ bio = r1_bio->bios[0]; for (i = 0; i < RESYNC_PAGES; i++) { page = alloc_page(gfp_flags); if (unlikely(!page)) goto out_free_pages; bio->bi_io_vec[i].bv_page = page; } r1_bio->master_bio = NULL; return r1_bio; out_free_pages: for ( ; i > 0 ; i--) __free_page(bio->bi_io_vec[i-1].bv_page); out_free_bio: while ( ++j < pi->raid_disks ) bio_put(r1_bio->bios[j]); r1bio_pool_free(r1_bio, data); return NULL; } static void r1buf_pool_free(void *__r1_bio, void *data) { struct pool_info *pi = data; int i; r1bio_t *r1bio = __r1_bio; struct bio *bio = r1bio->bios[0]; for (i = 0; i < RESYNC_PAGES; i++) { __free_page(bio->bi_io_vec[i].bv_page); bio->bi_io_vec[i].bv_page = NULL; } for (i=0 ; i < pi->raid_disks; i++) bio_put(r1bio->bios[i]); r1bio_pool_free(r1bio, data); } static void put_all_bios(conf_t *conf, r1bio_t *r1_bio) { int i; for (i = 0; i < conf->raid_disks; i++) { struct bio **bio = r1_bio->bios + i; if (*bio) bio_put(*bio); *bio = NULL; } } static inline void free_r1bio(r1bio_t *r1_bio) { unsigned long flags; conf_t *conf = mddev_to_conf(r1_bio->mddev); /* * Wake up any possible resync thread that waits for the device * to go idle. */ spin_lock_irqsave(&conf->resync_lock, flags); if (!--conf->nr_pending) { wake_up(&conf->wait_idle); wake_up(&conf->wait_resume); } spin_unlock_irqrestore(&conf->resync_lock, flags); put_all_bios(conf, r1_bio); mempool_free(r1_bio, conf->r1bio_pool); } static inline void put_buf(r1bio_t *r1_bio) { conf_t *conf = mddev_to_conf(r1_bio->mddev); unsigned long flags; mempool_free(r1_bio, conf->r1buf_pool); spin_lock_irqsave(&conf->resync_lock, flags); if (!conf->barrier) BUG(); --conf->barrier; wake_up(&conf->wait_resume); wake_up(&conf->wait_idle); if (!--conf->nr_pending) { wake_up(&conf->wait_idle); wake_up(&conf->wait_resume); } spin_unlock_irqrestore(&conf->resync_lock, flags); } static void reschedule_retry(r1bio_t *r1_bio) { unsigned long flags; mddev_t *mddev = r1_bio->mddev; conf_t *conf = mddev_to_conf(mddev); spin_lock_irqsave(&conf->device_lock, flags); list_add(&r1_bio->retry_list, &conf->retry_list); spin_unlock_irqrestore(&conf->device_lock, flags); md_wakeup_thread(mddev->thread); } /* * raid_end_bio_io() is called when we have finished servicing a mirrored * operation and are ready to return a success/failure code to the buffer * cache layer. */ static void raid_end_bio_io(r1bio_t *r1_bio) { struct bio *bio = r1_bio->master_bio; bio_endio(bio, bio->bi_size, test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); free_r1bio(r1_bio); } /* * Update disk head position estimator based on IRQ completion info. */ static inline void update_head_pos(int disk, r1bio_t *r1_bio) { conf_t *conf = mddev_to_conf(r1_bio->mddev); conf->mirrors[disk].head_position = r1_bio->sector + (r1_bio->sectors); } static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); int mirror; conf_t *conf = mddev_to_conf(r1_bio->mddev); if (bio->bi_size) return 1; mirror = r1_bio->read_disk; /* * this branch is our 'one mirror IO has finished' event handler: */ if (!uptodate) md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); else /* * Set R1BIO_Uptodate in our master bio, so that * we will return a good error code for to the higher * levels even if IO on some other mirrored buffer fails. * * The 'master' represents the composite IO operation to * user-side. So if something waits for IO, then it will * wait for the 'master' bio. */ set_bit(R1BIO_Uptodate, &r1_bio->state); update_head_pos(mirror, r1_bio); /* * we have only one bio on the read side */ if (uptodate) raid_end_bio_io(r1_bio); else { /* * oops, read error: */ char b[BDEVNAME_SIZE]; if (printk_ratelimit()) printk(KERN_ERR "raid1: %s: rescheduling sector %llu\n", bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector); reschedule_retry(r1_bio); } rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); return 0; } static int raid1_end_write_request(struct bio *bio, unsigned int bytes_done, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); int mirror; conf_t *conf = mddev_to_conf(r1_bio->mddev); if (bio->bi_size) return 1; for (mirror = 0; mirror < conf->raid_disks; mirror++) if (r1_bio->bios[mirror] == bio) break; /* * this branch is our 'one mirror IO has finished' event handler: */ if (!uptodate) { md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); /* an I/O failed, we can't clear the bitmap */ set_bit(R1BIO_Degraded, &r1_bio->state); } else /* * Set R1BIO_Uptodate in our master bio, so that * we will return a good error code for to the higher * levels even if IO on some other mirrored buffer fails. * * The 'master' represents the composite IO operation to * user-side. So if something waits for IO, then it will * wait for the 'master' bio. */ set_bit(R1BIO_Uptodate, &r1_bio->state); update_head_pos(mirror, r1_bio); /* * * Let's see if all mirrored write operations have finished * already. */ if (atomic_dec_and_test(&r1_bio->remaining)) { /* clear the bitmap if all writes complete successfully */ bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, r1_bio->sectors, !test_bit(R1BIO_Degraded, &r1_bio->state)); md_write_end(r1_bio->mddev); raid_end_bio_io(r1_bio); } rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); return 0; } /* * This routine returns the disk from which the requested read should * be done. There is a per-array 'next expected sequential IO' sector * number - if this matches on the next IO then we use the last disk. * There is also a per-disk 'last know head position' sector that is * maintained from IRQ contexts, both the normal and the resync IO * completion handlers update this position correctly. If there is no * perfect sequential match then we pick the disk whose head is closest. * * If there are 2 mirrors in the same 2 devices, performance degrades * because position is mirror, not device based. * * The rdev for the device selected will have nr_pending incremented. */ static int read_balance(conf_t *conf, r1bio_t *r1_bio) { const unsigned long this_sector = r1_bio->sector; int new_disk = conf->last_used, disk = new_disk; const int sectors = r1_bio->sectors; sector_t new_distance, current_distance; mdk_rdev_t *new_rdev, *rdev; rcu_read_lock(); /* * Check if it if we can balance. We can balance on the whole * device if no resync is going on, or below the resync window. * We take the first readable disk when above the resync window. */ retry: if (conf->mddev->recovery_cp < MaxSector && (this_sector + sectors >= conf->next_resync)) { /* Choose the first operation device, for consistancy */ new_disk = 0; while ((new_rdev=conf->mirrors[new_disk].rdev) == NULL || !new_rdev->in_sync) { new_disk++; if (new_disk == conf->raid_disks) { new_disk = -1; break; } } goto rb_out; } /* make sure the disk is operational */ while ((new_rdev=conf->mirrors[new_disk].rdev) == NULL || !new_rdev->in_sync) { if (new_disk <= 0) new_disk = conf->raid_disks; new_disk--; if (new_disk == disk) { new_disk = -1; goto rb_out; } } disk = new_disk; /* now disk == new_disk == starting point for search */ /* * Don't change to another disk for sequential reads: */ if (conf->next_seq_sect == this_sector) goto rb_out; if (this_sector == conf->mirrors[new_disk].head_position) goto rb_out; current_distance = abs(this_sector - conf->mirrors[disk].head_position); /* Find the disk whose head is closest */ do { if (disk <= 0) disk = conf->raid_disks; disk--; if ((rdev=conf->mirrors[disk].rdev) == NULL || !rdev->in_sync) continue; if (!atomic_read(&rdev->nr_pending)) { new_disk = disk; new_rdev = rdev; break; } new_distance = abs(this_sector - conf->mirrors[disk].head_position); if (new_distance < current_distance) { current_distance = new_distance; new_disk = disk; new_rdev = rdev; } } while (disk != conf->last_used); rb_out: if (new_disk >= 0) { conf->next_seq_sect = this_sector + sectors; conf->last_used = new_disk; atomic_inc(&new_rdev->nr_pending); if (!new_rdev->in_sync) { /* cannot risk returning a device that failed * before we inc'ed nr_pending */ atomic_dec(&new_rdev->nr_pending); goto retry; } } rcu_read_unlock(); return new_disk; } static void unplug_slaves(mddev_t *mddev) { conf_t *conf = mddev_to_conf(mddev); int i; rcu_read_lock(); for (i=0; iraid_disks; i++) { mdk_rdev_t *rdev = conf->mirrors[i].rdev; if (rdev && !rdev->faulty && atomic_read(&rdev->nr_pending)) { request_queue_t *r_queue = bdev_get_queue(rdev->bdev); atomic_inc(&rdev->nr_pending); rcu_read_unlock(); if (r_queue->unplug_fn) r_queue->unplug_fn(r_queue); rdev_dec_pending(rdev, mddev); rcu_read_lock(); } } rcu_read_unlock(); } static void raid1_unplug(request_queue_t *q) { mddev_t *mddev = q->queuedata; unplug_slaves(mddev); md_wakeup_thread(mddev->thread); } static int raid1_issue_flush(request_queue_t *q, struct gendisk *disk, sector_t *error_sector) { mddev_t *mddev = q->queuedata; conf_t *conf = mddev_to_conf(mddev); int i, ret = 0; rcu_read_lock(); for (i=0; iraid_disks && ret == 0; i++) { mdk_rdev_t *rdev = conf->mirrors[i].rdev; if (rdev && !rdev->faulty) { struct block_device *bdev = rdev->bdev; request_queue_t *r_queue = bdev_get_queue(bdev); if (!r_queue->issue_flush_fn) ret = -EOPNOTSUPP; else { atomic_inc(&rdev->nr_pending); rcu_read_unlock(); ret = r_queue->issue_flush_fn(r_queue, bdev->bd_disk, error_sector); rdev_dec_pending(rdev, mddev); rcu_read_lock(); } } } rcu_read_unlock(); return ret; } /* * Throttle resync depth, so that we can both get proper overlapping of * requests, but are still able to handle normal requests quickly. */ #define RESYNC_DEPTH 32 static void device_barrier(conf_t *conf, sector_t sect) { spin_lock_irq(&conf->resync_lock); wait_event_lock_irq(conf->wait_idle, !waitqueue_active(&conf->wait_resume), conf->resync_lock, raid1_unplug(conf->mddev->queue)); if (!conf->barrier++) { wait_event_lock_irq(conf->wait_idle, !conf->nr_pending, conf->resync_lock, raid1_unplug(conf->mddev->queue)); if (conf->nr_pending) BUG(); } wait_event_lock_irq(conf->wait_resume, conf->barrier < RESYNC_DEPTH, conf->resync_lock, raid1_unplug(conf->mddev->queue)); conf->next_resync = sect; spin_unlock_irq(&conf->resync_lock); } static int make_request(request_queue_t *q, struct bio * bio) { mddev_t *mddev = q->queuedata; conf_t *conf = mddev_to_conf(mddev); mirror_info_t *mirror; r1bio_t *r1_bio; struct bio *read_bio; int i, targets = 0, disks; mdk_rdev_t *rdev; struct bitmap *bitmap = mddev->bitmap; unsigned long flags; struct bio_list bl; if (unlikely(bio_barrier(bio))) { bio_endio(bio, bio->bi_size, -EOPNOTSUPP); return 0; } /* * Register the new request and wait if the reconstruction * thread has put up a bar for new requests. * Continue immediately if no resync is active currently. */ md_write_start(mddev, bio); /* wait on superblock update early */ spin_lock_irq(&conf->resync_lock); wait_event_lock_irq(conf->wait_resume, !conf->barrier, conf->resync_lock, ); conf->nr_pending++; spin_unlock_irq(&conf->resync_lock); if (bio_data_dir(bio)==WRITE) { disk_stat_inc(mddev->gendisk, writes); disk_stat_add(mddev->gendisk, write_sectors, bio_sectors(bio)); } else { disk_stat_inc(mddev->gendisk, reads); disk_stat_add(mddev->gendisk, read_sectors, bio_sectors(bio)); } /* * make_request() can abort the operation when READA is being * used and no empty request is available. * */ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); r1_bio->master_bio = bio; r1_bio->sectors = bio->bi_size >> 9; r1_bio->state = 0; r1_bio->mddev = mddev; r1_bio->sector = bio->bi_sector; r1_bio->state = 0; if (bio_data_dir(bio) == READ) { /* * read balancing logic: */ int rdisk = read_balance(conf, r1_bio); if (rdisk < 0) { /* couldn't find anywhere to read from */ raid_end_bio_io(r1_bio); return 0; } mirror = conf->mirrors + rdisk; r1_bio->read_disk = rdisk; read_bio = bio_clone(bio, GFP_NOIO); r1_bio->bios[rdisk] = read_bio; read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset; read_bio->bi_bdev = mirror->rdev->bdev; read_bio->bi_end_io = raid1_end_read_request; read_bio->bi_rw = READ; read_bio->bi_private = r1_bio; generic_make_request(read_bio); return 0; } /* * WRITE: */ /* first select target devices under spinlock and * inc refcount on their rdev. Record them by setting * bios[x] to bio */ disks = conf->raid_disks; #if 0 { static int first=1; if (first) printk("First Write sector %llu disks %d\n", (unsigned long long)r1_bio->sector, disks); first = 0; } #endif rcu_read_lock(); for (i = 0; i < disks; i++) { if ((rdev=conf->mirrors[i].rdev) != NULL && !rdev->faulty) { atomic_inc(&rdev->nr_pending); if (rdev->faulty) { atomic_dec(&rdev->nr_pending); r1_bio->bios[i] = NULL; } else r1_bio->bios[i] = bio; targets++; } else r1_bio->bios[i] = NULL; } rcu_read_unlock(); if (targets < conf->raid_disks) { /* array is degraded, we will not clear the bitmap * on I/O completion (see raid1_end_write_request) */ set_bit(R1BIO_Degraded, &r1_bio->state); } atomic_set(&r1_bio->remaining, 0); bio_list_init(&bl); for (i = 0; i < disks; i++) { struct bio *mbio; if (!r1_bio->bios[i]) continue; mbio = bio_clone(bio, GFP_NOIO); r1_bio->bios[i] = mbio; mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; mbio->bi_bdev = conf->mirrors[i].rdev->bdev; mbio->bi_end_io = raid1_end_write_request; mbio->bi_rw = WRITE; mbio->bi_private = r1_bio; atomic_inc(&r1_bio->remaining); bio_list_add(&bl, mbio); } bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors); spin_lock_irqsave(&conf->device_lock, flags); bio_list_merge(&conf->pending_bio_list, &bl); bio_list_init(&bl); blk_plug_device(mddev->queue); spin_unlock_irqrestore(&conf->device_lock, flags); #if 0 while ((bio = bio_list_pop(&bl)) != NULL) generic_make_request(bio); #endif return 0; } static void status(struct seq_file *seq, mddev_t *mddev) { conf_t *conf = mddev_to_conf(mddev); int i; seq_printf(seq, " [%d/%d] [", conf->raid_disks, conf->working_disks); for (i = 0; i < conf->raid_disks; i++) seq_printf(seq, "%s", conf->mirrors[i].rdev && conf->mirrors[i].rdev->in_sync ? "U" : "_"); seq_printf(seq, "]"); } static void error(mddev_t *mddev, mdk_rdev_t *rdev) { char b[BDEVNAME_SIZE]; conf_t *conf = mddev_to_conf(mddev); /* * If it is not operational, then we have already marked it as dead * else if it is the last working disks, ignore the error, let the * next level up know. * else mark the drive as failed */ if (rdev->in_sync && conf->working_disks == 1) /* * Don't fail the drive, act as though we were just a * normal single drive */ return; if (rdev->in_sync) { mddev->degraded++; conf->working_disks--; /* * if recovery is running, make sure it aborts. */ set_bit(MD_RECOVERY_ERR, &mddev->recovery); } rdev->in_sync = 0; rdev->faulty = 1; mddev->sb_dirty = 1; printk(KERN_ALERT "raid1: Disk failure on %s, disabling device. \n" " Operation continuing on %d devices\n", bdevname(rdev->bdev,b), conf->working_disks); } static void print_conf(conf_t *conf) { int i; mirror_info_t *tmp; printk("RAID1 conf printout:\n"); if (!conf) { printk("(!conf)\n"); return; } printk(" --- wd:%d rd:%d\n", conf->working_disks, conf->raid_disks); for (i = 0; i < conf->raid_disks; i++) { char b[BDEVNAME_SIZE]; tmp = conf->mirrors + i; if (tmp->rdev) printk(" disk %d, wo:%d, o:%d, dev:%s\n", i, !tmp->rdev->in_sync, !tmp->rdev->faulty, bdevname(tmp->rdev->bdev,b)); } } static void close_sync(conf_t *conf) { spin_lock_irq(&conf->resync_lock); wait_event_lock_irq(conf->wait_resume, !conf->barrier, conf->resync_lock, raid1_unplug(conf->mddev->queue)); spin_unlock_irq(&conf->resync_lock); if (conf->barrier) BUG(); if (waitqueue_active(&conf->wait_idle)) BUG(); mempool_destroy(conf->r1buf_pool); conf->r1buf_pool = NULL; } static int raid1_spare_active(mddev_t *mddev) { int i; conf_t *conf = mddev->private; mirror_info_t *tmp; /* * Find all failed disks within the RAID1 configuration * and mark them readable */ for (i = 0; i < conf->raid_disks; i++) { tmp = conf->mirrors + i; if (tmp->rdev && !tmp->rdev->faulty && !tmp->rdev->in_sync) { conf->working_disks++; mddev->degraded--; tmp->rdev->in_sync = 1; } } print_conf(conf); return 0; } static int raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) { conf_t *conf = mddev->private; int found = 0; int mirror = 0; mirror_info_t *p; if (rdev->saved_raid_disk >= 0 && conf->mirrors[rdev->saved_raid_disk].rdev == NULL) mirror = rdev->saved_raid_disk; for (mirror=0; mirror < mddev->raid_disks; mirror++) if ( !(p=conf->mirrors+mirror)->rdev) { blk_queue_stack_limits(mddev->queue, rdev->bdev->bd_disk->queue); /* as we don't honour merge_bvec_fn, we must never risk * violating it, so limit ->max_sector to one PAGE, as * a one page request is never in violation. */ if (rdev->bdev->bd_disk->queue->merge_bvec_fn && mddev->queue->max_sectors > (PAGE_SIZE>>9)) blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); p->head_position = 0; rdev->raid_disk = mirror; found = 1; if (rdev->saved_raid_disk != mirror) conf->fullsync = 1; p->rdev = rdev; break; } print_conf(conf); return found; } static int raid1_remove_disk(mddev_t *mddev, int number) { conf_t *conf = mddev->private; int err = 0; mdk_rdev_t *rdev; mirror_info_t *p = conf->mirrors+ number; print_conf(conf); rdev = p->rdev; if (rdev) { if (rdev->in_sync || atomic_read(&rdev->nr_pending)) { err = -EBUSY; goto abort; } p->rdev = NULL; synchronize_rcu(); if (atomic_read(&rdev->nr_pending)) { /* lost the race, try later */ err = -EBUSY; p->rdev = rdev; } } abort: print_conf(conf); return err; } static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); conf_t *conf = mddev_to_conf(r1_bio->mddev); if (bio->bi_size) return 1; if (r1_bio->bios[r1_bio->read_disk] != bio) BUG(); update_head_pos(r1_bio->read_disk, r1_bio); /* * we have read a block, now it needs to be re-written, * or re-read if the read failed. * We don't do much here, just schedule handling by raid1d */ if (!uptodate) { md_error(r1_bio->mddev, conf->mirrors[r1_bio->read_disk].rdev); } else set_bit(R1BIO_Uptodate, &r1_bio->state); rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev); reschedule_retry(r1_bio); return 0; } static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); r1bio_t * r1_bio = (r1bio_t *)(bio->bi_private); mddev_t *mddev = r1_bio->mddev; conf_t *conf = mddev_to_conf(mddev); int i; int mirror=0; if (bio->bi_size) return 1; for (i = 0; i < conf->raid_disks; i++) if (r1_bio->bios[i] == bio) { mirror = i; break; } if (!uptodate) md_error(mddev, conf->mirrors[mirror].rdev); update_head_pos(mirror, r1_bio); if (atomic_dec_and_test(&r1_bio->remaining)) { md_done_sync(mddev, r1_bio->sectors, uptodate); put_buf(r1_bio); } rdev_dec_pending(conf->mirrors[mirror].rdev, mddev); return 0; } static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) { conf_t *conf = mddev_to_conf(mddev); int i; int disks = conf->raid_disks; struct bio *bio, *wbio; bio = r1_bio->bios[r1_bio->read_disk]; /* if (r1_bio->sector == 0) printk("First sync write startss\n"); */ /* * schedule writes */ if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { /* * There is no point trying a read-for-reconstruct as * reconstruct is about to be aborted */ char b[BDEVNAME_SIZE]; printk(KERN_ALERT "raid1: %s: unrecoverable I/O read error" " for block %llu\n", bdevname(bio->bi_bdev,b), (unsigned long long)r1_bio->sector); md_done_sync(mddev, r1_bio->sectors, 0); put_buf(r1_bio); return; } atomic_set(&r1_bio->remaining, 1); for (i = 0; i < disks ; i++) { wbio = r1_bio->bios[i]; if (wbio->bi_end_io != end_sync_write) continue; atomic_inc(&conf->mirrors[i].rdev->nr_pending); atomic_inc(&r1_bio->remaining); md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9); generic_make_request(wbio); } if (atomic_dec_and_test(&r1_bio->remaining)) { /* if we're here, all write(s) have completed, so clean up */ md_done_sync(mddev, r1_bio->sectors, 1); put_buf(r1_bio); } } /* * This is a kernel thread which: * * 1. Retries failed read operations on working mirrors. * 2. Updates the raid superblock when problems encounter. * 3. Performs writes following reads for array syncronising. */ static void raid1d(mddev_t *mddev) { r1bio_t *r1_bio; struct bio *bio; unsigned long flags; conf_t *conf = mddev_to_conf(mddev); struct list_head *head = &conf->retry_list; int unplug=0; mdk_rdev_t *rdev; md_check_recovery(mddev); for (;;) { char b[BDEVNAME_SIZE]; spin_lock_irqsave(&conf->device_lock, flags); if (conf->pending_bio_list.head) { bio = bio_list_get(&conf->pending_bio_list); blk_remove_plug(mddev->queue); spin_unlock_irqrestore(&conf->device_lock, flags); /* flush any pending bitmap writes to disk before proceeding w/ I/O */ if (bitmap_unplug(mddev->bitmap) != 0) printk("%s: bitmap file write failed!\n", mdname(mddev)); while (bio) { /* submit pending writes */ struct bio *next = bio->bi_next; bio->bi_next = NULL; generic_make_request(bio); bio = next; } unplug = 1; continue; } if (list_empty(head)) break; r1_bio = list_entry(head->prev, r1bio_t, retry_list); list_del(head->prev); spin_unlock_irqrestore(&conf->device_lock, flags); mddev = r1_bio->mddev; conf = mddev_to_conf(mddev); if (test_bit(R1BIO_IsSync, &r1_bio->state)) { sync_request_write(mddev, r1_bio); unplug = 1; } else { int disk; bio = r1_bio->bios[r1_bio->read_disk]; if ((disk=read_balance(conf, r1_bio)) == -1) { printk(KERN_ALERT "raid1: %s: unrecoverable I/O" " read error for block %llu\n", bdevname(bio->bi_bdev,b), (unsigned long long)r1_bio->sector); raid_end_bio_io(r1_bio); } else { r1_bio->bios[r1_bio->read_disk] = NULL; r1_bio->read_disk = disk; bio_put(bio); bio = bio_clone(r1_bio->master_bio, GFP_NOIO); r1_bio->bios[r1_bio->read_disk] = bio; rdev = conf->mirrors[disk].rdev; if (printk_ratelimit()) printk(KERN_ERR "raid1: %s: redirecting sector %llu to" " another mirror\n", bdevname(rdev->bdev,b), (unsigned long long)r1_bio->sector); bio->bi_sector = r1_bio->sector + rdev->data_offset; bio->bi_bdev = rdev->bdev; bio->bi_end_io = raid1_end_read_request; bio->bi_rw = READ; bio->bi_private = r1_bio; unplug = 1; generic_make_request(bio); } } } spin_unlock_irqrestore(&conf->device_lock, flags); if (unplug) unplug_slaves(mddev); } static int init_resync(conf_t *conf) { int buffs; buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; if (conf->r1buf_pool) BUG(); conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, conf->poolinfo); if (!conf->r1buf_pool) return -ENOMEM; conf->next_resync = 0; return 0; } /* * perform a "sync" on one "block" * * We need to make sure that no normal I/O request - particularly write * requests - conflict with active sync requests. * * This is achieved by tracking pending requests and a 'barrier' concept * that can be installed to exclude normal IO requests. */ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) { conf_t *conf = mddev_to_conf(mddev); mirror_info_t *mirror; r1bio_t *r1_bio; struct bio *bio; sector_t max_sector, nr_sectors; int disk; int i; int write_targets = 0; int sync_blocks; int still_degraded = 0; if (!conf->r1buf_pool) { /* printk("sync start - bitmap %p\n", mddev->bitmap); */ if (init_resync(conf)) return 0; } max_sector = mddev->size << 1; if (sector_nr >= max_sector) { /* If we aborted, we need to abort the * sync on the 'current' bitmap chunk (there will * only be one in raid1 resync. * We can find the current addess in mddev->curr_resync */ if (mddev->curr_resync < max_sector) /* aborted */ bitmap_end_sync(mddev->bitmap, mddev->curr_resync, &sync_blocks, 1); else /* completed sync */ conf->fullsync = 0; bitmap_close_sync(mddev->bitmap); close_sync(conf); return 0; } /* before building a request, check if we can skip these blocks.. * This call the bitmap_start_sync doesn't actually record anything */ if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && !conf->fullsync) { /* We can skip this block, and probably several more */ *skipped = 1; return sync_blocks; } /* * If there is non-resync activity waiting for us then * put in a delay to throttle resync. */ if (!go_faster && waitqueue_active(&conf->wait_resume)) msleep_interruptible(1000); device_barrier(conf, sector_nr + RESYNC_SECTORS); /* * If reconstructing, and >1 working disc, * could dedicate one to rebuild and others to * service read requests .. */ disk = conf->last_used; /* make sure disk is operational */ while (conf->mirrors[disk].rdev == NULL || !conf->mirrors[disk].rdev->in_sync) { if (disk <= 0) disk = conf->raid_disks; disk--; if (disk == conf->last_used) break; } conf->last_used = disk; atomic_inc(&conf->mirrors[disk].rdev->nr_pending); mirror = conf->mirrors + disk; r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); spin_lock_irq(&conf->resync_lock); conf->nr_pending++; spin_unlock_irq(&conf->resync_lock); r1_bio->mddev = mddev; r1_bio->sector = sector_nr; r1_bio->state = 0; set_bit(R1BIO_IsSync, &r1_bio->state); r1_bio->read_disk = disk; for (i=0; i < conf->raid_disks; i++) { bio = r1_bio->bios[i]; /* take from bio_init */ bio->bi_next = NULL; bio->bi_flags |= 1 << BIO_UPTODATE; bio->bi_rw = 0; bio->bi_vcnt = 0; bio->bi_idx = 0; bio->bi_phys_segments = 0; bio->bi_hw_segments = 0; bio->bi_size = 0; bio->bi_end_io = NULL; bio->bi_private = NULL; if (i == disk) { bio->bi_rw = READ; bio->bi_end_io = end_sync_read; } else if (conf->mirrors[i].rdev == NULL || conf->mirrors[i].rdev->faulty) { still_degraded = 1; continue; } else if (!conf->mirrors[i].rdev->in_sync || sector_nr + RESYNC_SECTORS > mddev->recovery_cp) { bio->bi_rw = WRITE; bio->bi_end_io = end_sync_write; write_targets ++; } else /* no need to read or write here */ continue; bio->bi_sector = sector_nr + conf->mirrors[i].rdev->data_offset; bio->bi_bdev = conf->mirrors[i].rdev->bdev; bio->bi_private = r1_bio; } if (write_targets == 0) { /* There is nowhere to write, so all non-sync * drives must be failed - so we are finished */ sector_t rv = max_sector - sector_nr; *skipped = 1; put_buf(r1_bio); rdev_dec_pending(conf->mirrors[disk].rdev, mddev); return rv; } nr_sectors = 0; sync_blocks = 0; do { struct page *page; int len = PAGE_SIZE; if (sector_nr + (len>>9) > max_sector) len = (max_sector - sector_nr) << 9; if (len == 0) break; if (sync_blocks == 0) { if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, still_degraded) && !conf->fullsync) break; if (sync_blocks < (PAGE_SIZE>>9)) BUG(); if (len > (sync_blocks<<9)) len = sync_blocks<<9; } for (i=0 ; i < conf->raid_disks; i++) { bio = r1_bio->bios[i]; if (bio->bi_end_io) { page = r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page; if (bio_add_page(bio, page, len, 0) == 0) { /* stop here */ r1_bio->bios[0]->bi_io_vec[bio->bi_vcnt].bv_page = page; while (i > 0) { i--; bio = r1_bio->bios[i]; if (bio->bi_end_io==NULL) continue; /* remove last page from this bio */ bio->bi_vcnt--; bio->bi_size -= len; bio->bi_flags &= ~(1<< BIO_SEG_VALID); } goto bio_full; } } } nr_sectors += len>>9; sector_nr += len>>9; sync_blocks -= (len>>9); } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); bio_full: bio = r1_bio->bios[disk]; r1_bio->sectors = nr_sectors; md_sync_acct(mirror->rdev->bdev, nr_sectors); generic_make_request(bio); return nr_sectors; } static int run(mddev_t *mddev) { conf_t *conf; int i, j, disk_idx; mirror_info_t *disk; mdk_rdev_t *rdev; struct list_head *tmp; if (mddev->level != 1) { printk("raid1: %s: raid level not set to mirroring (%d)\n", mdname(mddev), mddev->level); goto out; } /* * copy the already verified devices into our private RAID1 * bookkeeping area. [whatever we allocate in run(), * should be freed in stop()] */ conf = kmalloc(sizeof(conf_t), GFP_KERNEL); mddev->private = conf; if (!conf) goto out_no_mem; memset(conf, 0, sizeof(*conf)); conf->mirrors = kmalloc(sizeof(struct mirror_info)*mddev->raid_disks, GFP_KERNEL); if (!conf->mirrors) goto out_no_mem; memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks); conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL); if (!conf->poolinfo) goto out_no_mem; conf->poolinfo->mddev = mddev; conf->poolinfo->raid_disks = mddev->raid_disks; conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, r1bio_pool_free, conf->poolinfo); if (!conf->r1bio_pool) goto out_no_mem; ITERATE_RDEV(mddev, rdev, tmp) { disk_idx = rdev->raid_disk; if (disk_idx >= mddev->raid_disks || disk_idx < 0) continue; disk = conf->mirrors + disk_idx; disk->rdev = rdev; blk_queue_stack_limits(mddev->queue, rdev->bdev->bd_disk->queue); /* as we don't honour merge_bvec_fn, we must never risk * violating it, so limit ->max_sector to one PAGE, as * a one page request is never in violation. */ if (rdev->bdev->bd_disk->queue->merge_bvec_fn && mddev->queue->max_sectors > (PAGE_SIZE>>9)) blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9); disk->head_position = 0; if (!rdev->faulty && rdev->in_sync) conf->working_disks++; } conf->raid_disks = mddev->raid_disks; conf->mddev = mddev; spin_lock_init(&conf->device_lock); INIT_LIST_HEAD(&conf->retry_list); if (conf->working_disks == 1) mddev->recovery_cp = MaxSector; spin_lock_init(&conf->resync_lock); init_waitqueue_head(&conf->wait_idle); init_waitqueue_head(&conf->wait_resume); bio_list_init(&conf->pending_bio_list); bio_list_init(&conf->flushing_bio_list); if (!conf->working_disks) { printk(KERN_ERR "raid1: no operational mirrors for %s\n", mdname(mddev)); goto out_free_conf; } mddev->degraded = 0; for (i = 0; i < conf->raid_disks; i++) { disk = conf->mirrors + i; if (!disk->rdev) { disk->head_position = 0; mddev->degraded++; } } /* * find the first working one and use it as a starting point * to read balancing. */ for (j = 0; j < conf->raid_disks && (!conf->mirrors[j].rdev || !conf->mirrors[j].rdev->in_sync) ; j++) /* nothing */; conf->last_used = j; mddev->thread = md_register_thread(raid1d, mddev, "%s_raid1"); if (!mddev->thread) { printk(KERN_ERR "raid1: couldn't allocate thread for %s\n", mdname(mddev)); goto out_free_conf; } if (mddev->bitmap) mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; printk(KERN_INFO "raid1: raid set %s active with %d out of %d mirrors\n", mdname(mddev), mddev->raid_disks - mddev->degraded, mddev->raid_disks); /* * Ok, everything is just fine now */ mddev->array_size = mddev->size; mddev->queue->unplug_fn = raid1_unplug; mddev->queue->issue_flush_fn = raid1_issue_flush; return 0; out_no_mem: printk(KERN_ERR "raid1: couldn't allocate memory for %s\n", mdname(mddev)); out_free_conf: if (conf) { if (conf->r1bio_pool) mempool_destroy(conf->r1bio_pool); kfree(conf->mirrors); kfree(conf->poolinfo); kfree(conf); mddev->private = NULL; } out: return -EIO; } static int stop(mddev_t *mddev) { conf_t *conf = mddev_to_conf(mddev); md_unregister_thread(mddev->thread); mddev->thread = NULL; blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ if (conf->r1bio_pool) mempool_destroy(conf->r1bio_pool); kfree(conf->mirrors); kfree(conf->poolinfo); kfree(conf); mddev->private = NULL; return 0; } static int raid1_resize(mddev_t *mddev, sector_t sectors) { /* no resync is happening, and there is enough space * on all devices, so we can resize. * We need to make sure resync covers any new space. * If the array is shrinking we should possibly wait until * any io in the removed space completes, but it hardly seems * worth it. */ mddev->array_size = sectors>>1; set_capacity(mddev->gendisk, mddev->array_size << 1); mddev->changed = 1; if (mddev->array_size > mddev->size && mddev->recovery_cp == MaxSector) { mddev->recovery_cp = mddev->size << 1; set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); } mddev->size = mddev->array_size; mddev->resync_max_sectors = sectors; return 0; } static int raid1_reshape(mddev_t *mddev, int raid_disks) { /* We need to: * 1/ resize the r1bio_pool * 2/ resize conf->mirrors * * We allocate a new r1bio_pool if we can. * Then raise a device barrier and wait until all IO stops. * Then resize conf->mirrors and swap in the new r1bio pool. * * At the same time, we "pack" the devices so that all the missing * devices have the higher raid_disk numbers. */ mempool_t *newpool, *oldpool; struct pool_info *newpoolinfo; mirror_info_t *newmirrors; conf_t *conf = mddev_to_conf(mddev); int cnt; int d, d2; if (raid_disks < conf->raid_disks) { cnt=0; for (d= 0; d < conf->raid_disks; d++) if (conf->mirrors[d].rdev) cnt++; if (cnt > raid_disks) return -EBUSY; } newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); if (!newpoolinfo) return -ENOMEM; newpoolinfo->mddev = mddev; newpoolinfo->raid_disks = raid_disks; newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, r1bio_pool_free, newpoolinfo); if (!newpool) { kfree(newpoolinfo); return -ENOMEM; } newmirrors = kmalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL); if (!newmirrors) { kfree(newpoolinfo); mempool_destroy(newpool); return -ENOMEM; } memset(newmirrors, 0, sizeof(struct mirror_info)*raid_disks); spin_lock_irq(&conf->resync_lock); conf->barrier++; wait_event_lock_irq(conf->wait_idle, !conf->nr_pending, conf->resync_lock, raid1_unplug(mddev->queue)); spin_unlock_irq(&conf->resync_lock); /* ok, everything is stopped */ oldpool = conf->r1bio_pool; conf->r1bio_pool = newpool; for (d=d2=0; d < conf->raid_disks; d++) if (conf->mirrors[d].rdev) { conf->mirrors[d].rdev->raid_disk = d2; newmirrors[d2++].rdev = conf->mirrors[d].rdev; } kfree(conf->mirrors); conf->mirrors = newmirrors; kfree(conf->poolinfo); conf->poolinfo = newpoolinfo; mddev->degraded += (raid_disks - conf->raid_disks); conf->raid_disks = mddev->raid_disks = raid_disks; conf->last_used = 0; /* just make sure it is in-range */ spin_lock_irq(&conf->resync_lock); conf->barrier--; spin_unlock_irq(&conf->resync_lock); wake_up(&conf->wait_resume); wake_up(&conf->wait_idle); set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); md_wakeup_thread(mddev->thread); mempool_destroy(oldpool); return 0; } void raid1_quiesce(mddev_t *mddev, int state) { conf_t *conf = mddev_to_conf(mddev); switch(state) { case 0: spin_lock_irq(&conf->resync_lock); conf->barrier++; wait_event_lock_irq(conf->wait_idle, !conf->nr_pending, conf->resync_lock, raid1_unplug(mddev->queue)); spin_unlock_irq(&conf->resync_lock); break; case 1: spin_lock_irq(&conf->resync_lock); conf->barrier--; spin_unlock_irq(&conf->resync_lock); wake_up(&conf->wait_resume); wake_up(&conf->wait_idle); break; } if (mddev->thread) { if (mddev->bitmap) mddev->thread->timeout = mddev->bitmap->daemon_sleep * HZ; else mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT; md_wakeup_thread(mddev->thread); } } static mdk_personality_t raid1_personality = { .name = "raid1", .owner = THIS_MODULE, .make_request = make_request, .run = run, .stop = stop, .status = status, .error_handler = error, .hot_add_disk = raid1_add_disk, .hot_remove_disk= raid1_remove_disk, .spare_active = raid1_spare_active, .sync_request = sync_request, .resize = raid1_resize, .reshape = raid1_reshape, .quiesce = raid1_quiesce, }; static int __init raid_init(void) { return register_md_personality(RAID1, &raid1_personality); } static void raid_exit(void) { unregister_md_personality(RAID1); } module_init(raid_init); module_exit(raid_exit); MODULE_LICENSE("GPL"); MODULE_ALIAS("md-personality-3"); /* RAID1 */