/* * 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 #include #include #include #include #include #include "md.h" #include "raid1.h" #include "bitmap.h" /* * Number of guaranteed r1bios in case of extreme VM load: */ #define NR_RAID1_BIOS 256 /* when we get a read error on a read-only array, we redirect to another * device without failing the first device, or trying to over-write to * correct the read error. To keep track of bad blocks on a per-bio * level, we store IO_BLOCKED in the appropriate 'bios' pointer */ #define IO_BLOCKED ((struct bio *)1) /* When we successfully write to a known bad-block, we need to remove the * bad-block marking which must be done from process context. So we record * the success by setting devs[n].bio to IO_MADE_GOOD */ #define IO_MADE_GOOD ((struct bio *)2) #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2) /* When there are this many requests queue to be written by * the raid1 thread, we become 'congested' to provide back-pressure * for writeback. */ static int max_queued_requests = 1024; static void allow_barrier(struct r1conf *conf, sector_t start_next_window, sector_t bi_sector); static void lower_barrier(struct r1conf *conf); static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data) { struct pool_info *pi = data; int size = offsetof(struct r1bio, bios[pi->raid_disks]); /* allocate a r1bio with room for raid_disks entries in the bios array */ return kzalloc(size, gfp_flags); } static void r1bio_pool_free(void *r1_bio, void *data) { kfree(r1_bio); } #define RESYNC_BLOCK_SIZE (64*1024) #define RESYNC_DEPTH 32 #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) #define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH) #define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9) #define NEXT_NORMALIO_DISTANCE (3 * RESYNC_WINDOW_SECTORS) static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) { struct pool_info *pi = data; struct r1bio *r1_bio; struct bio *bio; int i, j; r1_bio = r1bio_pool_alloc(gfp_flags, pi); if (!r1_bio) return NULL; /* * Allocate bios : 1 for reading, n-1 for writing */ for (j = pi->raid_disks ; j-- ; ) { bio = bio_kmalloc(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. * If this is a user-requested check/repair, allocate * RESYNC_PAGES for each bio. */ if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) j = pi->raid_disks; else j = 1; while(j--) { bio = r1_bio->bios[j]; bio->bi_vcnt = RESYNC_PAGES; if (bio_alloc_pages(bio, gfp_flags)) goto out_free_bio; } /* If not user-requests, copy the page pointers to all bios */ if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { for (i=0; iraid_disks; j++) r1_bio->bios[j]->bi_io_vec[i].bv_page = r1_bio->bios[0]->bi_io_vec[i].bv_page; } r1_bio->master_bio = NULL; return r1_bio; 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,j; struct r1bio *r1bio = __r1_bio; for (i = 0; i < RESYNC_PAGES; i++) for (j = pi->raid_disks; j-- ;) { if (j == 0 || r1bio->bios[j]->bi_io_vec[i].bv_page != r1bio->bios[0]->bi_io_vec[i].bv_page) safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page); } for (i=0 ; i < pi->raid_disks; i++) bio_put(r1bio->bios[i]); r1bio_pool_free(r1bio, data); } static void put_all_bios(struct r1conf *conf, struct r1bio *r1_bio) { int i; for (i = 0; i < conf->raid_disks * 2; i++) { struct bio **bio = r1_bio->bios + i; if (!BIO_SPECIAL(*bio)) bio_put(*bio); *bio = NULL; } } static void free_r1bio(struct r1bio *r1_bio) { struct r1conf *conf = r1_bio->mddev->private; put_all_bios(conf, r1_bio); mempool_free(r1_bio, conf->r1bio_pool); } static void put_buf(struct r1bio *r1_bio) { struct r1conf *conf = r1_bio->mddev->private; int i; for (i = 0; i < conf->raid_disks * 2; i++) { struct bio *bio = r1_bio->bios[i]; if (bio->bi_end_io) rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev); } mempool_free(r1_bio, conf->r1buf_pool); lower_barrier(conf); } static void reschedule_retry(struct r1bio *r1_bio) { unsigned long flags; struct mddev *mddev = r1_bio->mddev; struct r1conf *conf = mddev->private; spin_lock_irqsave(&conf->device_lock, flags); list_add(&r1_bio->retry_list, &conf->retry_list); conf->nr_queued ++; spin_unlock_irqrestore(&conf->device_lock, flags); wake_up(&conf->wait_barrier); 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 call_bio_endio(struct r1bio *r1_bio) { struct bio *bio = r1_bio->master_bio; int done; struct r1conf *conf = r1_bio->mddev->private; sector_t start_next_window = r1_bio->start_next_window; sector_t bi_sector = bio->bi_sector; if (bio->bi_phys_segments) { unsigned long flags; spin_lock_irqsave(&conf->device_lock, flags); bio->bi_phys_segments--; done = (bio->bi_phys_segments == 0); spin_unlock_irqrestore(&conf->device_lock, flags); /* * make_request() might be waiting for * bi_phys_segments to decrease */ wake_up(&conf->wait_barrier); } else done = 1; if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) clear_bit(BIO_UPTODATE, &bio->bi_flags); if (done) { bio_endio(bio, 0); /* * Wake up any possible resync thread that waits for the device * to go idle. */ allow_barrier(conf, start_next_window, bi_sector); } } static void raid_end_bio_io(struct r1bio *r1_bio) { struct bio *bio = r1_bio->master_bio; /* if nobody has done the final endio yet, do it now */ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { pr_debug("raid1: sync end %s on sectors %llu-%llu\n", (bio_data_dir(bio) == WRITE) ? "write" : "read", (unsigned long long) bio->bi_sector, (unsigned long long) bio->bi_sector + bio_sectors(bio) - 1); call_bio_endio(r1_bio); } free_r1bio(r1_bio); } /* * Update disk head position estimator based on IRQ completion info. */ static inline void update_head_pos(int disk, struct r1bio *r1_bio) { struct r1conf *conf = r1_bio->mddev->private; conf->mirrors[disk].head_position = r1_bio->sector + (r1_bio->sectors); } /* * Find the disk number which triggered given bio */ static int find_bio_disk(struct r1bio *r1_bio, struct bio *bio) { int mirror; struct r1conf *conf = r1_bio->mddev->private; int raid_disks = conf->raid_disks; for (mirror = 0; mirror < raid_disks * 2; mirror++) if (r1_bio->bios[mirror] == bio) break; BUG_ON(mirror == raid_disks * 2); update_head_pos(mirror, r1_bio); return mirror; } static void raid1_end_read_request(struct bio *bio, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct r1bio *r1_bio = bio->bi_private; int mirror; struct r1conf *conf = r1_bio->mddev->private; mirror = r1_bio->read_disk; /* * this branch is our 'one mirror IO has finished' event handler: */ update_head_pos(mirror, r1_bio); if (uptodate) set_bit(R1BIO_Uptodate, &r1_bio->state); else { /* If all other devices have failed, we want to return * the error upwards rather than fail the last device. * Here we redefine "uptodate" to mean "Don't want to retry" */ unsigned long flags; spin_lock_irqsave(&conf->device_lock, flags); if (r1_bio->mddev->degraded == conf->raid_disks || (r1_bio->mddev->degraded == conf->raid_disks-1 && !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))) uptodate = 1; spin_unlock_irqrestore(&conf->device_lock, flags); } if (uptodate) { raid_end_bio_io(r1_bio); rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); } else { /* * oops, read error: */ char b[BDEVNAME_SIZE]; printk_ratelimited( KERN_ERR "md/raid1:%s: %s: " "rescheduling sector %llu\n", mdname(conf->mddev), bdevname(conf->mirrors[mirror].rdev->bdev, b), (unsigned long long)r1_bio->sector); set_bit(R1BIO_ReadError, &r1_bio->state); reschedule_retry(r1_bio); /* don't drop the reference on read_disk yet */ } } static void close_write(struct r1bio *r1_bio) { /* it really is the end of this request */ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { /* free extra copy of the data pages */ int i = r1_bio->behind_page_count; while (i--) safe_put_page(r1_bio->behind_bvecs[i].bv_page); kfree(r1_bio->behind_bvecs); r1_bio->behind_bvecs = NULL; } /* 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), test_bit(R1BIO_BehindIO, &r1_bio->state)); md_write_end(r1_bio->mddev); } static void r1_bio_write_done(struct r1bio *r1_bio) { if (!atomic_dec_and_test(&r1_bio->remaining)) return; if (test_bit(R1BIO_WriteError, &r1_bio->state)) reschedule_retry(r1_bio); else { close_write(r1_bio); if (test_bit(R1BIO_MadeGood, &r1_bio->state)) reschedule_retry(r1_bio); else raid_end_bio_io(r1_bio); } } static void raid1_end_write_request(struct bio *bio, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct r1bio *r1_bio = bio->bi_private; int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state); struct r1conf *conf = r1_bio->mddev->private; struct bio *to_put = NULL; mirror = find_bio_disk(r1_bio, bio); /* * 'one mirror IO has finished' event handler: */ if (!uptodate) { set_bit(WriteErrorSeen, &conf->mirrors[mirror].rdev->flags); if (!test_and_set_bit(WantReplacement, &conf->mirrors[mirror].rdev->flags)) set_bit(MD_RECOVERY_NEEDED, & conf->mddev->recovery); set_bit(R1BIO_WriteError, &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. */ sector_t first_bad; int bad_sectors; r1_bio->bios[mirror] = NULL; to_put = bio; /* * Do not set R1BIO_Uptodate if the current device is * rebuilding or Faulty. This is because we cannot use * such device for properly reading the data back (we could * potentially use it, if the current write would have felt * before rdev->recovery_offset, but for simplicity we don't * check this here. */ if (test_bit(In_sync, &conf->mirrors[mirror].rdev->flags) && !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags)) set_bit(R1BIO_Uptodate, &r1_bio->state); /* Maybe we can clear some bad blocks. */ if (is_badblock(conf->mirrors[mirror].rdev, r1_bio->sector, r1_bio->sectors, &first_bad, &bad_sectors)) { r1_bio->bios[mirror] = IO_MADE_GOOD; set_bit(R1BIO_MadeGood, &r1_bio->state); } } if (behind) { if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) atomic_dec(&r1_bio->behind_remaining); /* * In behind mode, we ACK the master bio once the I/O * has safely reached all non-writemostly * disks. Setting the Returned bit ensures that this * gets done only once -- we don't ever want to return * -EIO here, instead we'll wait */ if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && test_bit(R1BIO_Uptodate, &r1_bio->state)) { /* Maybe we can return now */ if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { struct bio *mbio = r1_bio->master_bio; pr_debug("raid1: behind end write sectors" " %llu-%llu\n", (unsigned long long) mbio->bi_sector, (unsigned long long) mbio->bi_sector + bio_sectors(mbio) - 1); call_bio_endio(r1_bio); } } } if (r1_bio->bios[mirror] == NULL) rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); /* * Let's see if all mirrored write operations have finished * already. */ r1_bio_write_done(r1_bio); if (to_put) bio_put(to_put); } /* * 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(struct r1conf *conf, struct r1bio *r1_bio, int *max_sectors) { const sector_t this_sector = r1_bio->sector; int sectors; int best_good_sectors; int best_disk, best_dist_disk, best_pending_disk; int has_nonrot_disk; int disk; sector_t best_dist; unsigned int min_pending; struct md_rdev *rdev; int choose_first; int choose_next_idle; rcu_read_lock(); /* * Check 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: sectors = r1_bio->sectors; best_disk = -1; best_dist_disk = -1; best_dist = MaxSector; best_pending_disk = -1; min_pending = UINT_MAX; best_good_sectors = 0; has_nonrot_disk = 0; choose_next_idle = 0; if (conf->mddev->recovery_cp < MaxSector && (this_sector + sectors >= conf->next_resync)) choose_first = 1; else choose_first = 0; for (disk = 0 ; disk < conf->raid_disks * 2 ; disk++) { sector_t dist; sector_t first_bad; int bad_sectors; unsigned int pending; bool nonrot; rdev = rcu_dereference(conf->mirrors[disk].rdev); if (r1_bio->bios[disk] == IO_BLOCKED || rdev == NULL || test_bit(Unmerged, &rdev->flags) || test_bit(Faulty, &rdev->flags)) continue; if (!test_bit(In_sync, &rdev->flags) && rdev->recovery_offset < this_sector + sectors) continue; if (test_bit(WriteMostly, &rdev->flags)) { /* Don't balance among write-mostly, just * use the first as a last resort */ if (best_disk < 0) { if (is_badblock(rdev, this_sector, sectors, &first_bad, &bad_sectors)) { if (first_bad < this_sector) /* Cannot use this */ continue; best_good_sectors = first_bad - this_sector; } else best_good_sectors = sectors; best_disk = disk; } continue; } /* This is a reasonable device to use. It might * even be best. */ if (is_badblock(rdev, this_sector, sectors, &first_bad, &bad_sectors)) { if (best_dist < MaxSector) /* already have a better device */ continue; if (first_bad <= this_sector) { /* cannot read here. If this is the 'primary' * device, then we must not read beyond * bad_sectors from another device.. */ bad_sectors -= (this_sector - first_bad); if (choose_first && sectors > bad_sectors) sectors = bad_sectors; if (best_good_sectors > sectors) best_good_sectors = sectors; } else { sector_t good_sectors = first_bad - this_sector; if (good_sectors > best_good_sectors) { best_good_sectors = good_sectors; best_disk = disk; } if (choose_first) break; } continue; } else best_good_sectors = sectors; nonrot = blk_queue_nonrot(bdev_get_queue(rdev->bdev)); has_nonrot_disk |= nonrot; pending = atomic_read(&rdev->nr_pending); dist = abs(this_sector - conf->mirrors[disk].head_position); if (choose_first) { best_disk = disk; break; } /* Don't change to another disk for sequential reads */ if (conf->mirrors[disk].next_seq_sect == this_sector || dist == 0) { int opt_iosize = bdev_io_opt(rdev->bdev) >> 9; struct raid1_info *mirror = &conf->mirrors[disk]; best_disk = disk; /* * If buffered sequential IO size exceeds optimal * iosize, check if there is idle disk. If yes, choose * the idle disk. read_balance could already choose an * idle disk before noticing it's a sequential IO in * this disk. This doesn't matter because this disk * will idle, next time it will be utilized after the * first disk has IO size exceeds optimal iosize. In * this way, iosize of the first disk will be optimal * iosize at least. iosize of the second disk might be * small, but not a big deal since when the second disk * starts IO, the first disk is likely still busy. */ if (nonrot && opt_iosize > 0 && mirror->seq_start != MaxSector && mirror->next_seq_sect > opt_iosize && mirror->next_seq_sect - opt_iosize >= mirror->seq_start) { choose_next_idle = 1; continue; } break; } /* If device is idle, use it */ if (pending == 0) { best_disk = disk; break; } if (choose_next_idle) continue; if (min_pending > pending) { min_pending = pending; best_pending_disk = disk; } if (dist < best_dist) { best_dist = dist; best_dist_disk = disk; } } /* * If all disks are rotational, choose the closest disk. If any disk is * non-rotational, choose the disk with less pending request even the * disk is rotational, which might/might not be optimal for raids with * mixed ratation/non-rotational disks depending on workload. */ if (best_disk == -1) { if (has_nonrot_disk) best_disk = best_pending_disk; else best_disk = best_dist_disk; } if (best_disk >= 0) { rdev = rcu_dereference(conf->mirrors[best_disk].rdev); if (!rdev) goto retry; atomic_inc(&rdev->nr_pending); if (test_bit(Faulty, &rdev->flags)) { /* cannot risk returning a device that failed * before we inc'ed nr_pending */ rdev_dec_pending(rdev, conf->mddev); goto retry; } sectors = best_good_sectors; if (conf->mirrors[best_disk].next_seq_sect != this_sector) conf->mirrors[best_disk].seq_start = this_sector; conf->mirrors[best_disk].next_seq_sect = this_sector + sectors; } rcu_read_unlock(); *max_sectors = sectors; return best_disk; } static int raid1_mergeable_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct bio_vec *biovec) { struct mddev *mddev = q->queuedata; struct r1conf *conf = mddev->private; sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); int max = biovec->bv_len; if (mddev->merge_check_needed) { int disk; rcu_read_lock(); for (disk = 0; disk < conf->raid_disks * 2; disk++) { struct md_rdev *rdev = rcu_dereference( conf->mirrors[disk].rdev); if (rdev && !test_bit(Faulty, &rdev->flags)) { struct request_queue *q = bdev_get_queue(rdev->bdev); if (q->merge_bvec_fn) { bvm->bi_sector = sector + rdev->data_offset; bvm->bi_bdev = rdev->bdev; max = min(max, q->merge_bvec_fn( q, bvm, biovec)); } } } rcu_read_unlock(); } return max; } int md_raid1_congested(struct mddev *mddev, int bits) { struct r1conf *conf = mddev->private; int i, ret = 0; if ((bits & (1 << BDI_async_congested)) && conf->pending_count >= max_queued_requests) return 1; rcu_read_lock(); for (i = 0; i < conf->raid_disks * 2; i++) { struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); if (rdev && !test_bit(Faulty, &rdev->flags)) { struct request_queue *q = bdev_get_queue(rdev->bdev); BUG_ON(!q); /* Note the '|| 1' - when read_balance prefers * non-congested targets, it can be removed */ if ((bits & (1<backing_dev_info, bits); else ret &= bdi_congested(&q->backing_dev_info, bits); } } rcu_read_unlock(); return ret; } EXPORT_SYMBOL_GPL(md_raid1_congested); static int raid1_congested(void *data, int bits) { struct mddev *mddev = data; return mddev_congested(mddev, bits) || md_raid1_congested(mddev, bits); } static void flush_pending_writes(struct r1conf *conf) { /* Any writes that have been queued but are awaiting * bitmap updates get flushed here. */ spin_lock_irq(&conf->device_lock); if (conf->pending_bio_list.head) { struct bio *bio; bio = bio_list_get(&conf->pending_bio_list); conf->pending_count = 0; spin_unlock_irq(&conf->device_lock); /* flush any pending bitmap writes to * disk before proceeding w/ I/O */ bitmap_unplug(conf->mddev->bitmap); wake_up(&conf->wait_barrier); while (bio) { /* submit pending writes */ struct bio *next = bio->bi_next; bio->bi_next = NULL; if (unlikely((bio->bi_rw & REQ_DISCARD) && !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) /* Just ignore it */ bio_endio(bio, 0); else generic_make_request(bio); bio = next; } } else spin_unlock_irq(&conf->device_lock); } /* Barriers.... * Sometimes we need to suspend IO while we do something else, * either some resync/recovery, or reconfigure the array. * To do this we raise a 'barrier'. * The 'barrier' is a counter that can be raised multiple times * to count how many activities are happening which preclude * normal IO. * We can only raise the barrier if there is no pending IO. * i.e. if nr_pending == 0. * We choose only to raise the barrier if no-one is waiting for the * barrier to go down. This means that as soon as an IO request * is ready, no other operations which require a barrier will start * until the IO request has had a chance. * * So: regular IO calls 'wait_barrier'. When that returns there * is no backgroup IO happening, It must arrange to call * allow_barrier when it has finished its IO. * backgroup IO calls must call raise_barrier. Once that returns * there is no normal IO happeing. It must arrange to call * lower_barrier when the particular background IO completes. */ static void raise_barrier(struct r1conf *conf) { spin_lock_irq(&conf->resync_lock); /* Wait until no block IO is waiting */ wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, conf->resync_lock); /* block any new IO from starting */ conf->barrier++; /* For these conditions we must wait: * A: while the array is in frozen state * B: while barrier >= RESYNC_DEPTH, meaning resync reach * the max count which allowed. * C: next_resync + RESYNC_SECTORS > start_next_window, meaning * next resync will reach to the window which normal bios are * handling. */ wait_event_lock_irq(conf->wait_barrier, !conf->array_frozen && conf->barrier < RESYNC_DEPTH && (conf->start_next_window >= conf->next_resync + RESYNC_SECTORS), conf->resync_lock); spin_unlock_irq(&conf->resync_lock); } static void lower_barrier(struct r1conf *conf) { unsigned long flags; BUG_ON(conf->barrier <= 0); spin_lock_irqsave(&conf->resync_lock, flags); conf->barrier--; spin_unlock_irqrestore(&conf->resync_lock, flags); wake_up(&conf->wait_barrier); } static bool need_to_wait_for_sync(struct r1conf *conf, struct bio *bio) { bool wait = false; if (conf->array_frozen || !bio) wait = true; else if (conf->barrier && bio_data_dir(bio) == WRITE) { if (conf->next_resync < RESYNC_WINDOW_SECTORS) wait = true; else if ((conf->next_resync - RESYNC_WINDOW_SECTORS >= bio_end_sector(bio)) || (conf->next_resync + NEXT_NORMALIO_DISTANCE <= bio->bi_sector)) wait = false; else wait = true; } return wait; } static sector_t wait_barrier(struct r1conf *conf, struct bio *bio) { sector_t sector = 0; spin_lock_irq(&conf->resync_lock); if (need_to_wait_for_sync(conf, bio)) { conf->nr_waiting++; /* Wait for the barrier to drop. * However if there are already pending * requests (preventing the barrier from * rising completely), and the * pre-process bio queue isn't empty, * then don't wait, as we need to empty * that queue to get the nr_pending * count down. */ wait_event_lock_irq(conf->wait_barrier, !conf->array_frozen && (!conf->barrier || ((conf->start_next_window < conf->next_resync + RESYNC_SECTORS) && current->bio_list && !bio_list_empty(current->bio_list))), conf->resync_lock); conf->nr_waiting--; } if (bio && bio_data_dir(bio) == WRITE) { if (conf->next_resync + NEXT_NORMALIO_DISTANCE <= bio->bi_sector) { if (conf->start_next_window == MaxSector) conf->start_next_window = conf->next_resync + NEXT_NORMALIO_DISTANCE; if ((conf->start_next_window + NEXT_NORMALIO_DISTANCE) <= bio->bi_sector) conf->next_window_requests++; else conf->current_window_requests++; } if (bio->bi_sector >= conf->start_next_window) sector = conf->start_next_window; } conf->nr_pending++; spin_unlock_irq(&conf->resync_lock); return sector; } static void allow_barrier(struct r1conf *conf, sector_t start_next_window, sector_t bi_sector) { unsigned long flags; spin_lock_irqsave(&conf->resync_lock, flags); conf->nr_pending--; if (start_next_window) { if (start_next_window == conf->start_next_window) { if (conf->start_next_window + NEXT_NORMALIO_DISTANCE <= bi_sector) conf->next_window_requests--; else conf->current_window_requests--; } else conf->current_window_requests--; if (!conf->current_window_requests) { if (conf->next_window_requests) { conf->current_window_requests = conf->next_window_requests; conf->next_window_requests = 0; conf->start_next_window += NEXT_NORMALIO_DISTANCE; } else conf->start_next_window = MaxSector; } } spin_unlock_irqrestore(&conf->resync_lock, flags); wake_up(&conf->wait_barrier); } static void freeze_array(struct r1conf *conf, int extra) { /* stop syncio and normal IO and wait for everything to * go quite. * We wait until nr_pending match nr_queued+extra * This is called in the context of one normal IO request * that has failed. Thus any sync request that might be pending * will be blocked by nr_pending, and we need to wait for * pending IO requests to complete or be queued for re-try. * Thus the number queued (nr_queued) plus this request (extra) * must match the number of pending IOs (nr_pending) before * we continue. */ spin_lock_irq(&conf->resync_lock); conf->array_frozen = 1; wait_event_lock_irq_cmd(conf->wait_barrier, conf->nr_pending == conf->nr_queued+extra, conf->resync_lock, flush_pending_writes(conf)); spin_unlock_irq(&conf->resync_lock); } static void unfreeze_array(struct r1conf *conf) { /* reverse the effect of the freeze */ spin_lock_irq(&conf->resync_lock); conf->array_frozen = 0; wake_up(&conf->wait_barrier); spin_unlock_irq(&conf->resync_lock); } /* duplicate the data pages for behind I/O */ static void alloc_behind_pages(struct bio *bio, struct r1bio *r1_bio) { int i; struct bio_vec *bvec; struct bio_vec *bvecs = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), GFP_NOIO); if (unlikely(!bvecs)) return; bio_for_each_segment_all(bvec, bio, i) { bvecs[i] = *bvec; bvecs[i].bv_page = alloc_page(GFP_NOIO); if (unlikely(!bvecs[i].bv_page)) goto do_sync_io; memcpy(kmap(bvecs[i].bv_page) + bvec->bv_offset, kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); kunmap(bvecs[i].bv_page); kunmap(bvec->bv_page); } r1_bio->behind_bvecs = bvecs; r1_bio->behind_page_count = bio->bi_vcnt; set_bit(R1BIO_BehindIO, &r1_bio->state); return; do_sync_io: for (i = 0; i < bio->bi_vcnt; i++) if (bvecs[i].bv_page) put_page(bvecs[i].bv_page); kfree(bvecs); pr_debug("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); } struct raid1_plug_cb { struct blk_plug_cb cb; struct bio_list pending; int pending_cnt; }; static void raid1_unplug(struct blk_plug_cb *cb, bool from_schedule) { struct raid1_plug_cb *plug = container_of(cb, struct raid1_plug_cb, cb); struct mddev *mddev = plug->cb.data; struct r1conf *conf = mddev->private; struct bio *bio; if (from_schedule || current->bio_list) { spin_lock_irq(&conf->device_lock); bio_list_merge(&conf->pending_bio_list, &plug->pending); conf->pending_count += plug->pending_cnt; spin_unlock_irq(&conf->device_lock); wake_up(&conf->wait_barrier); md_wakeup_thread(mddev->thread); kfree(plug); return; } /* we aren't scheduling, so we can do the write-out directly. */ bio = bio_list_get(&plug->pending); bitmap_unplug(mddev->bitmap); wake_up(&conf->wait_barrier); while (bio) { /* submit pending writes */ struct bio *next = bio->bi_next; bio->bi_next = NULL; if (unlikely((bio->bi_rw & REQ_DISCARD) && !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) /* Just ignore it */ bio_endio(bio, 0); else generic_make_request(bio); bio = next; } kfree(plug); } static void make_request(struct mddev *mddev, struct bio * bio) { struct r1conf *conf = mddev->private; struct raid1_info *mirror; struct r1bio *r1_bio; struct bio *read_bio; int i, disks; struct bitmap *bitmap; unsigned long flags; const int rw = bio_data_dir(bio); const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA)); const unsigned long do_discard = (bio->bi_rw & (REQ_DISCARD | REQ_SECURE)); const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME); struct md_rdev *blocked_rdev; struct blk_plug_cb *cb; struct raid1_plug_cb *plug = NULL; int first_clone; int sectors_handled; int max_sectors; sector_t start_next_window; /* * 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 */ if (bio_data_dir(bio) == WRITE && bio_end_sector(bio) > mddev->suspend_lo && bio->bi_sector < mddev->suspend_hi) { /* As the suspend_* range is controlled by * userspace, we want an interruptible * wait. */ DEFINE_WAIT(w); for (;;) { flush_signals(current); prepare_to_wait(&conf->wait_barrier, &w, TASK_INTERRUPTIBLE); if (bio_end_sector(bio) <= mddev->suspend_lo || bio->bi_sector >= mddev->suspend_hi) break; schedule(); } finish_wait(&conf->wait_barrier, &w); } start_next_window = wait_barrier(conf, bio); bitmap = mddev->bitmap; /* * 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_sectors(bio); r1_bio->state = 0; r1_bio->mddev = mddev; r1_bio->sector = bio->bi_sector; /* We might need to issue multiple reads to different * devices if there are bad blocks around, so we keep * track of the number of reads in bio->bi_phys_segments. * If this is 0, there is only one r1_bio and no locking * will be needed when requests complete. If it is * non-zero, then it is the number of not-completed requests. */ bio->bi_phys_segments = 0; clear_bit(BIO_SEG_VALID, &bio->bi_flags); if (rw == READ) { /* * read balancing logic: */ int rdisk; read_again: rdisk = read_balance(conf, r1_bio, &max_sectors); if (rdisk < 0) { /* couldn't find anywhere to read from */ raid_end_bio_io(r1_bio); return; } mirror = conf->mirrors + rdisk; if (test_bit(WriteMostly, &mirror->rdev->flags) && bitmap) { /* Reading from a write-mostly device must * take care not to over-take any writes * that are 'behind' */ wait_event(bitmap->behind_wait, atomic_read(&bitmap->behind_writes) == 0); } r1_bio->read_disk = rdisk; read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector, max_sectors); 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 | do_sync; read_bio->bi_private = r1_bio; if (max_sectors < r1_bio->sectors) { /* could not read all from this device, so we will * need another r1_bio. */ sectors_handled = (r1_bio->sector + max_sectors - bio->bi_sector); r1_bio->sectors = max_sectors; spin_lock_irq(&conf->device_lock); if (bio->bi_phys_segments == 0) bio->bi_phys_segments = 2; else bio->bi_phys_segments++; spin_unlock_irq(&conf->device_lock); /* Cannot call generic_make_request directly * as that will be queued in __make_request * and subsequent mempool_alloc might block waiting * for it. So hand bio over to raid1d. */ reschedule_retry(r1_bio); r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); r1_bio->master_bio = bio; r1_bio->sectors = bio_sectors(bio) - sectors_handled; r1_bio->state = 0; r1_bio->mddev = mddev; r1_bio->sector = bio->bi_sector + sectors_handled; goto read_again; } else generic_make_request(read_bio); return; } /* * WRITE: */ if (conf->pending_count >= max_queued_requests) { md_wakeup_thread(mddev->thread); wait_event(conf->wait_barrier, conf->pending_count < max_queued_requests); } /* first select target devices under rcu_lock and * inc refcount on their rdev. Record them by setting * bios[x] to bio * If there are known/acknowledged bad blocks on any device on * which we have seen a write error, we want to avoid writing those * blocks. * This potentially requires several writes to write around * the bad blocks. Each set of writes gets it's own r1bio * with a set of bios attached. */ disks = conf->raid_disks * 2; retry_write: r1_bio->start_next_window = start_next_window; blocked_rdev = NULL; rcu_read_lock(); max_sectors = r1_bio->sectors; for (i = 0; i < disks; i++) { struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { atomic_inc(&rdev->nr_pending); blocked_rdev = rdev; break; } r1_bio->bios[i] = NULL; if (!rdev || test_bit(Faulty, &rdev->flags) || test_bit(Unmerged, &rdev->flags)) { if (i < conf->raid_disks) set_bit(R1BIO_Degraded, &r1_bio->state); continue; } atomic_inc(&rdev->nr_pending); if (test_bit(WriteErrorSeen, &rdev->flags)) { sector_t first_bad; int bad_sectors; int is_bad; is_bad = is_badblock(rdev, r1_bio->sector, max_sectors, &first_bad, &bad_sectors); if (is_bad < 0) { /* mustn't write here until the bad block is * acknowledged*/ set_bit(BlockedBadBlocks, &rdev->flags); blocked_rdev = rdev; break; } if (is_bad && first_bad <= r1_bio->sector) { /* Cannot write here at all */ bad_sectors -= (r1_bio->sector - first_bad); if (bad_sectors < max_sectors) /* mustn't write more than bad_sectors * to other devices yet */ max_sectors = bad_sectors; rdev_dec_pending(rdev, mddev); /* We don't set R1BIO_Degraded as that * only applies if the disk is * missing, so it might be re-added, * and we want to know to recover this * chunk. * In this case the device is here, * and the fact that this chunk is not * in-sync is recorded in the bad * block log */ continue; } if (is_bad) { int good_sectors = first_bad - r1_bio->sector; if (good_sectors < max_sectors) max_sectors = good_sectors; } } r1_bio->bios[i] = bio; } rcu_read_unlock(); if (unlikely(blocked_rdev)) { /* Wait for this device to become unblocked */ int j; sector_t old = start_next_window; for (j = 0; j < i; j++) if (r1_bio->bios[j]) rdev_dec_pending(conf->mirrors[j].rdev, mddev); r1_bio->state = 0; allow_barrier(conf, start_next_window, bio->bi_sector); md_wait_for_blocked_rdev(blocked_rdev, mddev); start_next_window = wait_barrier(conf, bio); /* * We must make sure the multi r1bios of bio have * the same value of bi_phys_segments */ if (bio->bi_phys_segments && old && old != start_next_window) /* Wait for the former r1bio(s) to complete */ wait_event(conf->wait_barrier, bio->bi_phys_segments == 1); goto retry_write; } if (max_sectors < r1_bio->sectors) { /* We are splitting this write into multiple parts, so * we need to prepare for allocating another r1_bio. */ r1_bio->sectors = max_sectors; spin_lock_irq(&conf->device_lock); if (bio->bi_phys_segments == 0) bio->bi_phys_segments = 2; else bio->bi_phys_segments++; spin_unlock_irq(&conf->device_lock); } sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector; atomic_set(&r1_bio->remaining, 1); atomic_set(&r1_bio->behind_remaining, 0); first_clone = 1; for (i = 0; i < disks; i++) { struct bio *mbio; if (!r1_bio->bios[i]) continue; mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors); if (first_clone) { /* do behind I/O ? * Not if there are too many, or cannot * allocate memory, or a reader on WriteMostly * is waiting for behind writes to flush */ if (bitmap && (atomic_read(&bitmap->behind_writes) < mddev->bitmap_info.max_write_behind) && !waitqueue_active(&bitmap->behind_wait)) alloc_behind_pages(mbio, r1_bio); bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors, test_bit(R1BIO_BehindIO, &r1_bio->state)); first_clone = 0; } if (r1_bio->behind_bvecs) { struct bio_vec *bvec; int j; /* * We trimmed the bio, so _all is legit */ bio_for_each_segment_all(bvec, mbio, j) bvec->bv_page = r1_bio->behind_bvecs[j].bv_page; if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) atomic_inc(&r1_bio->behind_remaining); } 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 | do_flush_fua | do_sync | do_discard | do_same; mbio->bi_private = r1_bio; atomic_inc(&r1_bio->remaining); cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug)); if (cb) plug = container_of(cb, struct raid1_plug_cb, cb); else plug = NULL; spin_lock_irqsave(&conf->device_lock, flags); if (plug) { bio_list_add(&plug->pending, mbio); plug->pending_cnt++; } else { bio_list_add(&conf->pending_bio_list, mbio); conf->pending_count++; } spin_unlock_irqrestore(&conf->device_lock, flags); if (!plug) md_wakeup_thread(mddev->thread); } /* Mustn't call r1_bio_write_done before this next test, * as it could result in the bio being freed. */ if (sectors_handled < bio_sectors(bio)) { r1_bio_write_done(r1_bio); /* We need another r1_bio. It has already been counted * in bio->bi_phys_segments */ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); r1_bio->master_bio = bio; r1_bio->sectors = bio_sectors(bio) - sectors_handled; r1_bio->state = 0; r1_bio->mddev = mddev; r1_bio->sector = bio->bi_sector + sectors_handled; goto retry_write; } r1_bio_write_done(r1_bio); /* In case raid1d snuck in to freeze_array */ wake_up(&conf->wait_barrier); } static void status(struct seq_file *seq, struct mddev *mddev) { struct r1conf *conf = mddev->private; int i; seq_printf(seq, " [%d/%d] [", conf->raid_disks, conf->raid_disks - mddev->degraded); rcu_read_lock(); for (i = 0; i < conf->raid_disks; i++) { struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); seq_printf(seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); } rcu_read_unlock(); seq_printf(seq, "]"); } static void error(struct mddev *mddev, struct md_rdev *rdev) { char b[BDEVNAME_SIZE]; struct r1conf *conf = mddev->private; /* * 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 (test_bit(In_sync, &rdev->flags) && (conf->raid_disks - mddev->degraded) == 1) { /* * Don't fail the drive, act as though we were just a * normal single drive. * However don't try a recovery from this drive as * it is very likely to fail. */ conf->recovery_disabled = mddev->recovery_disabled; return; } set_bit(Blocked, &rdev->flags); if (test_and_clear_bit(In_sync, &rdev->flags)) { unsigned long flags; spin_lock_irqsave(&conf->device_lock, flags); mddev->degraded++; set_bit(Faulty, &rdev->flags); spin_unlock_irqrestore(&conf->device_lock, flags); /* * if recovery is running, make sure it aborts. */ set_bit(MD_RECOVERY_INTR, &mddev->recovery); } else set_bit(Faulty, &rdev->flags); set_bit(MD_CHANGE_DEVS, &mddev->flags); printk(KERN_ALERT "md/raid1:%s: Disk failure on %s, disabling device.\n" "md/raid1:%s: Operation continuing on %d devices.\n", mdname(mddev), bdevname(rdev->bdev, b), mdname(mddev), conf->raid_disks - mddev->degraded); } static void print_conf(struct r1conf *conf) { int i; printk(KERN_DEBUG "RAID1 conf printout:\n"); if (!conf) { printk(KERN_DEBUG "(!conf)\n"); return; } printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->raid_disks - conf->mddev->degraded, conf->raid_disks); rcu_read_lock(); for (i = 0; i < conf->raid_disks; i++) { char b[BDEVNAME_SIZE]; struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); if (rdev) printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n", i, !test_bit(In_sync, &rdev->flags), !test_bit(Faulty, &rdev->flags), bdevname(rdev->bdev,b)); } rcu_read_unlock(); } static void close_sync(struct r1conf *conf) { wait_barrier(conf, NULL); allow_barrier(conf, 0, 0); mempool_destroy(conf->r1buf_pool); conf->r1buf_pool = NULL; conf->next_resync = 0; conf->start_next_window = MaxSector; } static int raid1_spare_active(struct mddev *mddev) { int i; struct r1conf *conf = mddev->private; int count = 0; unsigned long flags; /* * Find all failed disks within the RAID1 configuration * and mark them readable. * Called under mddev lock, so rcu protection not needed. */ for (i = 0; i < conf->raid_disks; i++) { struct md_rdev *rdev = conf->mirrors[i].rdev; struct md_rdev *repl = conf->mirrors[conf->raid_disks + i].rdev; if (repl && repl->recovery_offset == MaxSector && !test_bit(Faulty, &repl->flags) && !test_and_set_bit(In_sync, &repl->flags)) { /* replacement has just become active */ if (!rdev || !test_and_clear_bit(In_sync, &rdev->flags)) count++; if (rdev) { /* Replaced device not technically * faulty, but we need to be sure * it gets removed and never re-added */ set_bit(Faulty, &rdev->flags); sysfs_notify_dirent_safe( rdev->sysfs_state); } } if (rdev && rdev->recovery_offset == MaxSector && !test_bit(Faulty, &rdev->flags) && !test_and_set_bit(In_sync, &rdev->flags)) { count++; sysfs_notify_dirent_safe(rdev->sysfs_state); } } spin_lock_irqsave(&conf->device_lock, flags); mddev->degraded -= count; spin_unlock_irqrestore(&conf->device_lock, flags); print_conf(conf); return count; } static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev) { struct r1conf *conf = mddev->private; int err = -EEXIST; int mirror = 0; struct raid1_info *p; int first = 0; int last = conf->raid_disks - 1; struct request_queue *q = bdev_get_queue(rdev->bdev); if (mddev->recovery_disabled == conf->recovery_disabled) return -EBUSY; if (rdev->raid_disk >= 0) first = last = rdev->raid_disk; if (q->merge_bvec_fn) { set_bit(Unmerged, &rdev->flags); mddev->merge_check_needed = 1; } for (mirror = first; mirror <= last; mirror++) { p = conf->mirrors+mirror; if (!p->rdev) { if (mddev->gendisk) disk_stack_limits(mddev->gendisk, rdev->bdev, rdev->data_offset << 9); p->head_position = 0; rdev->raid_disk = mirror; err = 0; /* As all devices are equivalent, we don't need a full recovery * if this was recently any drive of the array */ if (rdev->saved_raid_disk < 0) conf->fullsync = 1; rcu_assign_pointer(p->rdev, rdev); break; } if (test_bit(WantReplacement, &p->rdev->flags) && p[conf->raid_disks].rdev == NULL) { /* Add this device as a replacement */ clear_bit(In_sync, &rdev->flags); set_bit(Replacement, &rdev->flags); rdev->raid_disk = mirror; err = 0; conf->fullsync = 1; rcu_assign_pointer(p[conf->raid_disks].rdev, rdev); break; } } if (err == 0 && test_bit(Unmerged, &rdev->flags)) { /* Some requests might not have seen this new * merge_bvec_fn. We must wait for them to complete * before merging the device fully. * First we make sure any code which has tested * our function has submitted the request, then * we wait for all outstanding requests to complete. */ synchronize_sched(); freeze_array(conf, 0); unfreeze_array(conf); clear_bit(Unmerged, &rdev->flags); } md_integrity_add_rdev(rdev, mddev); if (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev))) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); print_conf(conf); return err; } static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev) { struct r1conf *conf = mddev->private; int err = 0; int number = rdev->raid_disk; struct raid1_info *p = conf->mirrors + number; if (rdev != p->rdev) p = conf->mirrors + conf->raid_disks + number; print_conf(conf); if (rdev == p->rdev) { if (test_bit(In_sync, &rdev->flags) || atomic_read(&rdev->nr_pending)) { err = -EBUSY; goto abort; } /* Only remove non-faulty devices if recovery * is not possible. */ if (!test_bit(Faulty, &rdev->flags) && mddev->recovery_disabled != conf->recovery_disabled && mddev->degraded < conf->raid_disks) { 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; goto abort; } else if (conf->mirrors[conf->raid_disks + number].rdev) { /* We just removed a device that is being replaced. * Move down the replacement. We drain all IO before * doing this to avoid confusion. */ struct md_rdev *repl = conf->mirrors[conf->raid_disks + number].rdev; freeze_array(conf, 0); clear_bit(Replacement, &repl->flags); p->rdev = repl; conf->mirrors[conf->raid_disks + number].rdev = NULL; unfreeze_array(conf); clear_bit(WantReplacement, &rdev->flags); } else clear_bit(WantReplacement, &rdev->flags); err = md_integrity_register(mddev); } abort: print_conf(conf); return err; } static void end_sync_read(struct bio *bio, int error) { struct r1bio *r1_bio = bio->bi_private; 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 (test_bit(BIO_UPTODATE, &bio->bi_flags)) set_bit(R1BIO_Uptodate, &r1_bio->state); if (atomic_dec_and_test(&r1_bio->remaining)) reschedule_retry(r1_bio); } static void end_sync_write(struct bio *bio, int error) { int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); struct r1bio *r1_bio = bio->bi_private; struct mddev *mddev = r1_bio->mddev; struct r1conf *conf = mddev->private; int mirror=0; sector_t first_bad; int bad_sectors; mirror = find_bio_disk(r1_bio, bio); if (!uptodate) { sector_t sync_blocks = 0; sector_t s = r1_bio->sector; long sectors_to_go = r1_bio->sectors; /* make sure these bits doesn't get cleared. */ do { bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1); s += sync_blocks; sectors_to_go -= sync_blocks; } while (sectors_to_go > 0); set_bit(WriteErrorSeen, &conf->mirrors[mirror].rdev->flags); if (!test_and_set_bit(WantReplacement, &conf->mirrors[mirror].rdev->flags)) set_bit(MD_RECOVERY_NEEDED, & mddev->recovery); set_bit(R1BIO_WriteError, &r1_bio->state); } else if (is_badblock(conf->mirrors[mirror].rdev, r1_bio->sector, r1_bio->sectors, &first_bad, &bad_sectors) && !is_badblock(conf->mirrors[r1_bio->read_disk].rdev, r1_bio->sector, r1_bio->sectors, &first_bad, &bad_sectors) ) set_bit(R1BIO_MadeGood, &r1_bio->state); if (atomic_dec_and_test(&r1_bio->remaining)) { int s = r1_bio->sectors; if (test_bit(R1BIO_MadeGood, &r1_bio->state) || test_bit(R1BIO_WriteError, &r1_bio->state)) reschedule_retry(r1_bio); else { put_buf(r1_bio); md_done_sync(mddev, s, uptodate); } } } static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector, int sectors, struct page *page, int rw) { if (sync_page_io(rdev, sector, sectors << 9, page, rw, false)) /* success */ return 1; if (rw == WRITE) { set_bit(WriteErrorSeen, &rdev->flags); if (!test_and_set_bit(WantReplacement, &rdev->flags)) set_bit(MD_RECOVERY_NEEDED, & rdev->mddev->recovery); } /* need to record an error - either for the block or the device */ if (!rdev_set_badblocks(rdev, sector, sectors, 0)) md_error(rdev->mddev, rdev); return 0; } static int fix_sync_read_error(struct r1bio *r1_bio) { /* Try some synchronous reads of other devices to get * good data, much like with normal read errors. Only * read into the pages we already have so we don't * need to re-issue the read request. * We don't need to freeze the array, because being in an * active sync request, there is no normal IO, and * no overlapping syncs. * We don't need to check is_badblock() again as we * made sure that anything with a bad block in range * will have bi_end_io clear. */ struct mddev *mddev = r1_bio->mddev; struct r1conf *conf = mddev->private; struct bio *bio = r1_bio->bios[r1_bio->read_disk]; sector_t sect = r1_bio->sector; int sectors = r1_bio->sectors; int idx = 0; while(sectors) { int s = sectors; int d = r1_bio->read_disk; int success = 0; struct md_rdev *rdev; int start; if (s > (PAGE_SIZE>>9)) s = PAGE_SIZE >> 9; do { if (r1_bio->bios[d]->bi_end_io == end_sync_read) { /* No rcu protection needed here devices * can only be removed when no resync is * active, and resync is currently active */ rdev = conf->mirrors[d].rdev; if (sync_page_io(rdev, sect, s<<9, bio->bi_io_vec[idx].bv_page, READ, false)) { success = 1; break; } } d++; if (d == conf->raid_disks * 2) d = 0; } while (!success && d != r1_bio->read_disk); if (!success) { char b[BDEVNAME_SIZE]; int abort = 0; /* Cannot read from anywhere, this block is lost. * Record a bad block on each device. If that doesn't * work just disable and interrupt the recovery. * Don't fail devices as that won't really help. */ printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error" " for block %llu\n", mdname(mddev), bdevname(bio->bi_bdev, b), (unsigned long long)r1_bio->sector); for (d = 0; d < conf->raid_disks * 2; d++) { rdev = conf->mirrors[d].rdev; if (!rdev || test_bit(Faulty, &rdev->flags)) continue; if (!rdev_set_badblocks(rdev, sect, s, 0)) abort = 1; } if (abort) { conf->recovery_disabled = mddev->recovery_disabled; set_bit(MD_RECOVERY_INTR, &mddev->recovery); md_done_sync(mddev, r1_bio->sectors, 0); put_buf(r1_bio); return 0; } /* Try next page */ sectors -= s; sect += s; idx++; continue; } start = d; /* write it back and re-read */ while (d != r1_bio->read_disk) { if (d == 0) d = conf->raid_disks * 2; d--; if (r1_bio->bios[d]->bi_end_io != end_sync_read) continue; rdev = conf->mirrors[d].rdev; if (r1_sync_page_io(rdev, sect, s, bio->bi_io_vec[idx].bv_page, WRITE) == 0) { r1_bio->bios[d]->bi_end_io = NULL; rdev_dec_pending(rdev, mddev); } } d = start; while (d != r1_bio->read_disk) { if (d == 0) d = conf->raid_disks * 2; d--; if (r1_bio->bios[d]->bi_end_io != end_sync_read) continue; rdev = conf->mirrors[d].rdev; if (r1_sync_page_io(rdev, sect, s, bio->bi_io_vec[idx].bv_page, READ) != 0) atomic_add(s, &rdev->corrected_errors); } sectors -= s; sect += s; idx ++; } set_bit(R1BIO_Uptodate, &r1_bio->state); set_bit(BIO_UPTODATE, &bio->bi_flags); return 1; } static int process_checks(struct r1bio *r1_bio) { /* We have read all readable devices. If we haven't * got the block, then there is no hope left. * If we have, then we want to do a comparison * and skip the write if everything is the same. * If any blocks failed to read, then we need to * attempt an over-write */ struct mddev *mddev = r1_bio->mddev; struct r1conf *conf = mddev->private; int primary; int i; int vcnt; /* Fix variable parts of all bios */ vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); for (i = 0; i < conf->raid_disks * 2; i++) { int j; int size; struct bio *b = r1_bio->bios[i]; if (b->bi_end_io != end_sync_read) continue; /* fixup the bio for reuse */ bio_reset(b); b->bi_vcnt = vcnt; b->bi_size = r1_bio->sectors << 9; b->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; b->bi_bdev = conf->mirrors[i].rdev->bdev; b->bi_end_io = end_sync_read; b->bi_private = r1_bio; size = b->bi_size; for (j = 0; j < vcnt ; j++) { struct bio_vec *bi; bi = &b->bi_io_vec[j]; bi->bv_offset = 0; if (size > PAGE_SIZE) bi->bv_len = PAGE_SIZE; else bi->bv_len = size; size -= PAGE_SIZE; } } for (primary = 0; primary < conf->raid_disks * 2; primary++) if (r1_bio->bios[primary]->bi_end_io == end_sync_read && test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { r1_bio->bios[primary]->bi_end_io = NULL; rdev_dec_pending(conf->mirrors[primary].rdev, mddev); break; } r1_bio->read_disk = primary; for (i = 0; i < conf->raid_disks * 2; i++) { int j; struct bio *pbio = r1_bio->bios[primary]; struct bio *sbio = r1_bio->bios[i]; if (sbio->bi_end_io != end_sync_read) continue; if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) { for (j = vcnt; j-- ; ) { struct page *p, *s; p = pbio->bi_io_vec[j].bv_page; s = sbio->bi_io_vec[j].bv_page; if (memcmp(page_address(p), page_address(s), sbio->bi_io_vec[j].bv_len)) break; } } else j = 0; if (j >= 0) atomic64_add(r1_bio->sectors, &mddev->resync_mismatches); if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) && test_bit(BIO_UPTODATE, &sbio->bi_flags))) { /* No need to write to this device. */ sbio->bi_end_io = NULL; rdev_dec_pending(conf->mirrors[i].rdev, mddev); continue; } bio_copy_data(sbio, pbio); } return 0; } static void sync_request_write(struct mddev *mddev, struct r1bio *r1_bio) { struct r1conf *conf = mddev->private; int i; int disks = conf->raid_disks * 2; struct bio *bio, *wbio; bio = r1_bio->bios[r1_bio->read_disk]; if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) /* ouch - failed to read all of that. */ if (!fix_sync_read_error(r1_bio)) return; if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) if (process_checks(r1_bio) < 0) return; /* * schedule writes */ atomic_set(&r1_bio->remaining, 1); for (i = 0; i < disks ; i++) { wbio = r1_bio->bios[i]; if (wbio->bi_end_io == NULL || (wbio->bi_end_io == end_sync_read && (i == r1_bio->read_disk || !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) continue; wbio->bi_rw = WRITE; wbio->bi_end_io = end_sync_write; atomic_inc(&r1_bio->remaining); md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio)); generic_make_request(wbio); } if (atomic_dec_and_test(&r1_bio->remaining)) { /* if we're here, all write(s) have completed, so clean up */ int s = r1_bio->sectors; if (test_bit(R1BIO_MadeGood, &r1_bio->state) || test_bit(R1BIO_WriteError, &r1_bio->state)) reschedule_retry(r1_bio); else { put_buf(r1_bio); md_done_sync(mddev, s, 1); } } } /* * 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 synchronising. */ static void fix_read_error(struct r1conf *conf, int read_disk, sector_t sect, int sectors) { struct mddev *mddev = conf->mddev; while(sectors) { int s = sectors; int d = read_disk; int success = 0; int start; struct md_rdev *rdev; if (s > (PAGE_SIZE>>9)) s = PAGE_SIZE >> 9; do { /* Note: no rcu protection needed here * as this is synchronous in the raid1d thread * which is the thread that might remove * a device. If raid1d ever becomes multi-threaded.... */ sector_t first_bad; int bad_sectors; rdev = conf->mirrors[d].rdev; if (rdev && (test_bit(In_sync, &rdev->flags) || (!test_bit(Faulty, &rdev->flags) && rdev->recovery_offset >= sect + s)) && is_badblock(rdev, sect, s, &first_bad, &bad_sectors) == 0 && sync_page_io(rdev, sect, s<<9, conf->tmppage, READ, false)) success = 1; else { d++; if (d == conf->raid_disks * 2) d = 0; } } while (!success && d != read_disk); if (!success) { /* Cannot read from anywhere - mark it bad */ struct md_rdev *rdev = conf->mirrors[read_disk].rdev; if (!rdev_set_badblocks(rdev, sect, s, 0)) md_error(mddev, rdev); break; } /* write it back and re-read */ start = d; while (d != read_disk) { if (d==0) d = conf->raid_disks * 2; d--; rdev = conf->mirrors[d].rdev; if (rdev && test_bit(In_sync, &rdev->flags)) r1_sync_page_io(rdev, sect, s, conf->tmppage, WRITE); } d = start; while (d != read_disk) { char b[BDEVNAME_SIZE]; if (d==0) d = conf->raid_disks * 2; d--; rdev = conf->mirrors[d].rdev; if (rdev && test_bit(In_sync, &rdev->flags)) { if (r1_sync_page_io(rdev, sect, s, conf->tmppage, READ)) { atomic_add(s, &rdev->corrected_errors); printk(KERN_INFO "md/raid1:%s: read error corrected " "(%d sectors at %llu on %s)\n", mdname(mddev), s, (unsigned long long)(sect + rdev->data_offset), bdevname(rdev->bdev, b)); } } } sectors -= s; sect += s; } } static int narrow_write_error(struct r1bio *r1_bio, int i) { struct mddev *mddev = r1_bio->mddev; struct r1conf *conf = mddev->private; struct md_rdev *rdev = conf->mirrors[i].rdev; /* bio has the data to be written to device 'i' where * we just recently had a write error. * We repeatedly clone the bio and trim down to one block, * then try the write. Where the write fails we record * a bad block. * It is conceivable that the bio doesn't exactly align with * blocks. We must handle this somehow. * * We currently own a reference on the rdev. */ int block_sectors; sector_t sector; int sectors; int sect_to_write = r1_bio->sectors; int ok = 1; if (rdev->badblocks.shift < 0) return 0; block_sectors = 1 << rdev->badblocks.shift; sector = r1_bio->sector; sectors = ((sector + block_sectors) & ~(sector_t)(block_sectors - 1)) - sector; while (sect_to_write) { struct bio *wbio; if (sectors > sect_to_write) sectors = sect_to_write; /* Write at 'sector' for 'sectors'*/ if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { unsigned vcnt = r1_bio->behind_page_count; struct bio_vec *vec = r1_bio->behind_bvecs; while (!vec->bv_page) { vec++; vcnt--; } wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev); memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec)); wbio->bi_vcnt = vcnt; } else { wbio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); } wbio->bi_rw = WRITE; wbio->bi_sector = r1_bio->sector; wbio->bi_size = r1_bio->sectors << 9; md_trim_bio(wbio, sector - r1_bio->sector, sectors); wbio->bi_sector += rdev->data_offset; wbio->bi_bdev = rdev->bdev; if (submit_bio_wait(WRITE, wbio) == 0) /* failure! */ ok = rdev_set_badblocks(rdev, sector, sectors, 0) && ok; bio_put(wbio); sect_to_write -= sectors; sector += sectors; sectors = block_sectors; } return ok; } static void handle_sync_write_finished(struct r1conf *conf, struct r1bio *r1_bio) { int m; int s = r1_bio->sectors; for (m = 0; m < conf->raid_disks * 2 ; m++) { struct md_rdev *rdev = conf->mirrors[m].rdev; struct bio *bio = r1_bio->bios[m]; if (bio->bi_end_io == NULL) continue; if (test_bit(BIO_UPTODATE, &bio->bi_flags) && test_bit(R1BIO_MadeGood, &r1_bio->state)) { rdev_clear_badblocks(rdev, r1_bio->sector, s, 0); } if (!test_bit(BIO_UPTODATE, &bio->bi_flags) && test_bit(R1BIO_WriteError, &r1_bio->state)) { if (!rdev_set_badblocks(rdev, r1_bio->sector, s, 0)) md_error(conf->mddev, rdev); } } put_buf(r1_bio); md_done_sync(conf->mddev, s, 1); } static void handle_write_finished(struct r1conf *conf, struct r1bio *r1_bio) { int m; for (m = 0; m < conf->raid_disks * 2 ; m++) if (r1_bio->bios[m] == IO_MADE_GOOD) { struct md_rdev *rdev = conf->mirrors[m].rdev; rdev_clear_badblocks(rdev, r1_bio->sector, r1_bio->sectors, 0); rdev_dec_pending(rdev, conf->mddev); } else if (r1_bio->bios[m] != NULL) { /* This drive got a write error. We need to * narrow down and record precise write * errors. */ if (!narrow_write_error(r1_bio, m)) { md_error(conf->mddev, conf->mirrors[m].rdev); /* an I/O failed, we can't clear the bitmap */ set_bit(R1BIO_Degraded, &r1_bio->state); } rdev_dec_pending(conf->mirrors[m].rdev, conf->mddev); } if (test_bit(R1BIO_WriteError, &r1_bio->state)) close_write(r1_bio); raid_end_bio_io(r1_bio); } static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio) { int disk; int max_sectors; struct mddev *mddev = conf->mddev; struct bio *bio; char b[BDEVNAME_SIZE]; struct md_rdev *rdev; clear_bit(R1BIO_ReadError, &r1_bio->state); /* we got a read error. Maybe the drive is bad. Maybe just * the block and we can fix it. * We freeze all other IO, and try reading the block from * other devices. When we find one, we re-write * and check it that fixes the read error. * This is all done synchronously while the array is * frozen */ if (mddev->ro == 0) { freeze_array(conf, 1); fix_read_error(conf, r1_bio->read_disk, r1_bio->sector, r1_bio->sectors); unfreeze_array(conf); } else md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev); bio = r1_bio->bios[r1_bio->read_disk]; bdevname(bio->bi_bdev, b); read_more: disk = read_balance(conf, r1_bio, &max_sectors); if (disk == -1) { printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O" " read error for block %llu\n", mdname(mddev), b, (unsigned long long)r1_bio->sector); raid_end_bio_io(r1_bio); } else { const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC; if (bio) { r1_bio->bios[r1_bio->read_disk] = mddev->ro ? IO_BLOCKED : NULL; bio_put(bio); } r1_bio->read_disk = disk; bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); md_trim_bio(bio, r1_bio->sector - bio->bi_sector, max_sectors); r1_bio->bios[r1_bio->read_disk] = bio; rdev = conf->mirrors[disk].rdev; printk_ratelimited(KERN_ERR "md/raid1:%s: redirecting sector %llu" " to other mirror: %s\n", mdname(mddev), (unsigned long long)r1_bio->sector, bdevname(rdev->bdev, b)); 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 | do_sync; bio->bi_private = r1_bio; if (max_sectors < r1_bio->sectors) { /* Drat - have to split this up more */ struct bio *mbio = r1_bio->master_bio; int sectors_handled = (r1_bio->sector + max_sectors - mbio->bi_sector); r1_bio->sectors = max_sectors; spin_lock_irq(&conf->device_lock); if (mbio->bi_phys_segments == 0) mbio->bi_phys_segments = 2; else mbio->bi_phys_segments++; spin_unlock_irq(&conf->device_lock); generic_make_request(bio); bio = NULL; r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); r1_bio->master_bio = mbio; r1_bio->sectors = bio_sectors(mbio) - sectors_handled; r1_bio->state = 0; set_bit(R1BIO_ReadError, &r1_bio->state); r1_bio->mddev = mddev; r1_bio->sector = mbio->bi_sector + sectors_handled; goto read_more; } else generic_make_request(bio); } } static void raid1d(struct md_thread *thread) { struct mddev *mddev = thread->mddev; struct r1bio *r1_bio; unsigned long flags; struct r1conf *conf = mddev->private; struct list_head *head = &conf->retry_list; struct blk_plug plug; md_check_recovery(mddev); blk_start_plug(&plug); for (;;) { flush_pending_writes(conf); spin_lock_irqsave(&conf->device_lock, flags); if (list_empty(head)) { spin_unlock_irqrestore(&conf->device_lock, flags); break; } r1_bio = list_entry(head->prev, struct r1bio, retry_list); list_del(head->prev); conf->nr_queued--; spin_unlock_irqrestore(&conf->device_lock, flags); mddev = r1_bio->mddev; conf = mddev->private; if (test_bit(R1BIO_IsSync, &r1_bio->state)) { if (test_bit(R1BIO_MadeGood, &r1_bio->state) || test_bit(R1BIO_WriteError, &r1_bio->state)) handle_sync_write_finished(conf, r1_bio); else sync_request_write(mddev, r1_bio); } else if (test_bit(R1BIO_MadeGood, &r1_bio->state) || test_bit(R1BIO_WriteError, &r1_bio->state)) handle_write_finished(conf, r1_bio); else if (test_bit(R1BIO_ReadError, &r1_bio->state)) handle_read_error(conf, r1_bio); else /* just a partial read to be scheduled from separate * context */ generic_make_request(r1_bio->bios[r1_bio->read_disk]); cond_resched(); if (mddev->flags & ~(1<r1buf_pool); 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(struct mddev *mddev, sector_t sector_nr, int *skipped, int go_faster) { struct r1conf *conf = mddev->private; struct r1bio *r1_bio; struct bio *bio; sector_t max_sector, nr_sectors; int disk = -1; int i; int wonly = -1; int write_targets = 0, read_targets = 0; sector_t sync_blocks; int still_degraded = 0; int good_sectors = RESYNC_SECTORS; int min_bad = 0; /* number of sectors that are bad in all devices */ if (!conf->r1buf_pool) if (init_resync(conf)) return 0; max_sector = mddev->dev_sectors; 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; } if (mddev->bitmap == NULL && mddev->recovery_cp == MaxSector && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && conf->fullsync == 0) { *skipped = 1; return max_sector - sector_nr; } /* 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 && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { /* We can skip this block, and probably several more */ *skipped = 1; return sync_blocks; } /* * If there is non-resync activity waiting for a turn, * and resync is going fast enough, * then let it though before starting on this new sync request. */ if (!go_faster && conf->nr_waiting) msleep_interruptible(1000); bitmap_cond_end_sync(mddev->bitmap, sector_nr); r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); raise_barrier(conf); conf->next_resync = sector_nr; rcu_read_lock(); /* * If we get a correctably read error during resync or recovery, * we might want to read from a different device. So we * flag all drives that could conceivably be read from for READ, * and any others (which will be non-In_sync devices) for WRITE. * If a read fails, we try reading from something else for which READ * is OK. */ r1_bio->mddev = mddev; r1_bio->sector = sector_nr; r1_bio->state = 0; set_bit(R1BIO_IsSync, &r1_bio->state); for (i = 0; i < conf->raid_disks * 2; i++) { struct md_rdev *rdev; bio = r1_bio->bios[i]; bio_reset(bio); rdev = rcu_dereference(conf->mirrors[i].rdev); if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { if (i < conf->raid_disks) still_degraded = 1; } else if (!test_bit(In_sync, &rdev->flags)) { bio->bi_rw = WRITE; bio->bi_end_io = end_sync_write; write_targets ++; } else { /* may need to read from here */ sector_t first_bad = MaxSector; int bad_sectors; if (is_badblock(rdev, sector_nr, good_sectors, &first_bad, &bad_sectors)) { if (first_bad > sector_nr) good_sectors = first_bad - sector_nr; else { bad_sectors -= (sector_nr - first_bad); if (min_bad == 0 || min_bad > bad_sectors) min_bad = bad_sectors; } } if (sector_nr < first_bad) { if (test_bit(WriteMostly, &rdev->flags)) { if (wonly < 0) wonly = i; } else { if (disk < 0) disk = i; } bio->bi_rw = READ; bio->bi_end_io = end_sync_read; read_targets++; } else if (!test_bit(WriteErrorSeen, &rdev->flags) && test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && !test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) { /* * The device is suitable for reading (InSync), * but has bad block(s) here. Let's try to correct them, * if we are doing resync or repair. Otherwise, leave * this device alone for this sync request. */ bio->bi_rw = WRITE; bio->bi_end_io = end_sync_write; write_targets++; } } if (bio->bi_end_io) { atomic_inc(&rdev->nr_pending); bio->bi_sector = sector_nr + rdev->data_offset; bio->bi_bdev = rdev->bdev; bio->bi_private = r1_bio; } } rcu_read_unlock(); if (disk < 0) disk = wonly; r1_bio->read_disk = disk; if (read_targets == 0 && min_bad > 0) { /* These sectors are bad on all InSync devices, so we * need to mark them bad on all write targets */ int ok = 1; for (i = 0 ; i < conf->raid_disks * 2 ; i++) if (r1_bio->bios[i]->bi_end_io == end_sync_write) { struct md_rdev *rdev = conf->mirrors[i].rdev; ok = rdev_set_badblocks(rdev, sector_nr, min_bad, 0 ) && ok; } set_bit(MD_CHANGE_DEVS, &mddev->flags); *skipped = 1; put_buf(r1_bio); if (!ok) { /* Cannot record the badblocks, so need to * abort the resync. * If there are multiple read targets, could just * fail the really bad ones ??? */ conf->recovery_disabled = mddev->recovery_disabled; set_bit(MD_RECOVERY_INTR, &mddev->recovery); return 0; } else return min_bad; } if (min_bad > 0 && min_bad < good_sectors) { /* only resync enough to reach the next bad->good * transition */ good_sectors = min_bad; } if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) /* extra read targets are also write targets */ write_targets += read_targets-1; if (write_targets == 0 || read_targets == 0) { /* There is nowhere to write, so all non-sync * drives must be failed - so we are finished */ sector_t rv; if (min_bad > 0) max_sector = sector_nr + min_bad; rv = max_sector - sector_nr; *skipped = 1; put_buf(r1_bio); return rv; } if (max_sector > mddev->resync_max) max_sector = mddev->resync_max; /* Don't do IO beyond here */ if (max_sector > sector_nr + good_sectors) max_sector = sector_nr + good_sectors; 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 && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) break; BUG_ON(sync_blocks < (PAGE_SIZE>>9)); if ((len >> 9) > sync_blocks) len = sync_blocks<<9; } for (i = 0 ; i < conf->raid_disks * 2; i++) { bio = r1_bio->bios[i]; if (bio->bi_end_io) { page = bio->bi_io_vec[bio->bi_vcnt].bv_page; if (bio_add_page(bio, page, len, 0) == 0) { /* stop here */ bio->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: r1_bio->sectors = nr_sectors; /* For a user-requested sync, we read all readable devices and do a * compare */ if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { atomic_set(&r1_bio->remaining, read_targets); for (i = 0; i < conf->raid_disks * 2 && read_targets; i++) { bio = r1_bio->bios[i]; if (bio->bi_end_io == end_sync_read) { read_targets--; md_sync_acct(bio->bi_bdev, nr_sectors); generic_make_request(bio); } } } else { atomic_set(&r1_bio->remaining, 1); bio = r1_bio->bios[r1_bio->read_disk]; md_sync_acct(bio->bi_bdev, nr_sectors); generic_make_request(bio); } return nr_sectors; } static sector_t raid1_size(struct mddev *mddev, sector_t sectors, int raid_disks) { if (sectors) return sectors; return mddev->dev_sectors; } static struct r1conf *setup_conf(struct mddev *mddev) { struct r1conf *conf; int i; struct raid1_info *disk; struct md_rdev *rdev; int err = -ENOMEM; conf = kzalloc(sizeof(struct r1conf), GFP_KERNEL); if (!conf) goto abort; conf->mirrors = kzalloc(sizeof(struct raid1_info) * mddev->raid_disks * 2, GFP_KERNEL); if (!conf->mirrors) goto abort; conf->tmppage = alloc_page(GFP_KERNEL); if (!conf->tmppage) goto abort; conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); if (!conf->poolinfo) goto abort; conf->poolinfo->raid_disks = mddev->raid_disks * 2; conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, r1bio_pool_free, conf->poolinfo); if (!conf->r1bio_pool) goto abort; conf->poolinfo->mddev = mddev; err = -EINVAL; spin_lock_init(&conf->device_lock); rdev_for_each(rdev, mddev) { struct request_queue *q; int disk_idx = rdev->raid_disk; if (disk_idx >= mddev->raid_disks || disk_idx < 0) continue; if (test_bit(Replacement, &rdev->flags)) disk = conf->mirrors + mddev->raid_disks + disk_idx; else disk = conf->mirrors + disk_idx; if (disk->rdev) goto abort; disk->rdev = rdev; q = bdev_get_queue(rdev->bdev); if (q->merge_bvec_fn) mddev->merge_check_needed = 1; disk->head_position = 0; disk->seq_start = MaxSector; } conf->raid_disks = mddev->raid_disks; conf->mddev = mddev; INIT_LIST_HEAD(&conf->retry_list); spin_lock_init(&conf->resync_lock); init_waitqueue_head(&conf->wait_barrier); bio_list_init(&conf->pending_bio_list); conf->pending_count = 0; conf->recovery_disabled = mddev->recovery_disabled - 1; conf->start_next_window = MaxSector; conf->current_window_requests = conf->next_window_requests = 0; err = -EIO; for (i = 0; i < conf->raid_disks * 2; i++) { disk = conf->mirrors + i; if (i < conf->raid_disks && disk[conf->raid_disks].rdev) { /* This slot has a replacement. */ if (!disk->rdev) { /* No original, just make the replacement * a recovering spare */ disk->rdev = disk[conf->raid_disks].rdev; disk[conf->raid_disks].rdev = NULL; } else if (!test_bit(In_sync, &disk->rdev->flags)) /* Original is not in_sync - bad */ goto abort; } if (!disk->rdev || !test_bit(In_sync, &disk->rdev->flags)) { disk->head_position = 0; if (disk->rdev && (disk->rdev->saved_raid_disk < 0)) conf->fullsync = 1; } } err = -ENOMEM; conf->thread = md_register_thread(raid1d, mddev, "raid1"); if (!conf->thread) { printk(KERN_ERR "md/raid1:%s: couldn't allocate thread\n", mdname(mddev)); goto abort; } return conf; abort: if (conf) { if (conf->r1bio_pool) mempool_destroy(conf->r1bio_pool); kfree(conf->mirrors); safe_put_page(conf->tmppage); kfree(conf->poolinfo); kfree(conf); } return ERR_PTR(err); } static int stop(struct mddev *mddev); static int run(struct mddev *mddev) { struct r1conf *conf; int i; struct md_rdev *rdev; int ret; bool discard_supported = false; if (mddev->level != 1) { printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n", mdname(mddev), mddev->level); return -EIO; } if (mddev->reshape_position != MaxSector) { printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n", mdname(mddev)); return -EIO; } /* * copy the already verified devices into our private RAID1 * bookkeeping area. [whatever we allocate in run(), * should be freed in stop()] */ if (mddev->private == NULL) conf = setup_conf(mddev); else conf = mddev->private; if (IS_ERR(conf)) return PTR_ERR(conf); if (mddev->queue) blk_queue_max_write_same_sectors(mddev->queue, 0); rdev_for_each(rdev, mddev) { if (!mddev->gendisk) continue; disk_stack_limits(mddev->gendisk, rdev->bdev, rdev->data_offset << 9); if (blk_queue_discard(bdev_get_queue(rdev->bdev))) discard_supported = true; } mddev->degraded = 0; for (i=0; i < conf->raid_disks; i++) if (conf->mirrors[i].rdev == NULL || !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || test_bit(Faulty, &conf->mirrors[i].rdev->flags)) mddev->degraded++; if (conf->raid_disks - mddev->degraded == 1) mddev->recovery_cp = MaxSector; if (mddev->recovery_cp != MaxSector) printk(KERN_NOTICE "md/raid1:%s: not clean" " -- starting background reconstruction\n", mdname(mddev)); printk(KERN_INFO "md/raid1:%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->thread = conf->thread; conf->thread = NULL; mddev->private = conf; md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); if (mddev->queue) { mddev->queue->backing_dev_info.congested_fn = raid1_congested; mddev->queue->backing_dev_info.congested_data = mddev; blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec); if (discard_supported) queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); else queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); } ret = md_integrity_register(mddev); if (ret) stop(mddev); return ret; } static int stop(struct mddev *mddev) { struct r1conf *conf = mddev->private; struct bitmap *bitmap = mddev->bitmap; /* wait for behind writes to complete */ if (bitmap && atomic_read(&bitmap->behind_writes) > 0) { printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n", mdname(mddev)); /* need to kick something here to make sure I/O goes? */ wait_event(bitmap->behind_wait, atomic_read(&bitmap->behind_writes) == 0); } freeze_array(conf, 0); unfreeze_array(conf); md_unregister_thread(&mddev->thread); if (conf->r1bio_pool) mempool_destroy(conf->r1bio_pool); kfree(conf->mirrors); safe_put_page(conf->tmppage); kfree(conf->poolinfo); kfree(conf); mddev->private = NULL; return 0; } static int raid1_resize(struct mddev *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. */ sector_t newsize = raid1_size(mddev, sectors, 0); if (mddev->external_size && mddev->array_sectors > newsize) return -EINVAL; if (mddev->bitmap) { int ret = bitmap_resize(mddev->bitmap, newsize, 0, 0); if (ret) return ret; } md_set_array_sectors(mddev, newsize); set_capacity(mddev->gendisk, mddev->array_sectors); revalidate_disk(mddev->gendisk); if (sectors > mddev->dev_sectors && mddev->recovery_cp > mddev->dev_sectors) { mddev->recovery_cp = mddev->dev_sectors; set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); } mddev->dev_sectors = sectors; mddev->resync_max_sectors = sectors; return 0; } static int raid1_reshape(struct mddev *mddev) { /* 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; struct raid1_info *newmirrors; struct r1conf *conf = mddev->private; int cnt, raid_disks; unsigned long flags; int d, d2, err; /* Cannot change chunk_size, layout, or level */ if (mddev->chunk_sectors != mddev->new_chunk_sectors || mddev->layout != mddev->new_layout || mddev->level != mddev->new_level) { mddev->new_chunk_sectors = mddev->chunk_sectors; mddev->new_layout = mddev->layout; mddev->new_level = mddev->level; return -EINVAL; } err = md_allow_write(mddev); if (err) return err; raid_disks = mddev->raid_disks + mddev->delta_disks; 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 * 2; newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, r1bio_pool_free, newpoolinfo); if (!newpool) { kfree(newpoolinfo); return -ENOMEM; } newmirrors = kzalloc(sizeof(struct raid1_info) * raid_disks * 2, GFP_KERNEL); if (!newmirrors) { kfree(newpoolinfo); mempool_destroy(newpool); return -ENOMEM; } freeze_array(conf, 0); /* ok, everything is stopped */ oldpool = conf->r1bio_pool; conf->r1bio_pool = newpool; for (d = d2 = 0; d < conf->raid_disks; d++) { struct md_rdev *rdev = conf->mirrors[d].rdev; if (rdev && rdev->raid_disk != d2) { sysfs_unlink_rdev(mddev, rdev); rdev->raid_disk = d2; sysfs_unlink_rdev(mddev, rdev); if (sysfs_link_rdev(mddev, rdev)) printk(KERN_WARNING "md/raid1:%s: cannot register rd%d\n", mdname(mddev), rdev->raid_disk); } if (rdev) newmirrors[d2++].rdev = rdev; } kfree(conf->mirrors); conf->mirrors = newmirrors; kfree(conf->poolinfo); conf->poolinfo = newpoolinfo; spin_lock_irqsave(&conf->device_lock, flags); mddev->degraded += (raid_disks - conf->raid_disks); spin_unlock_irqrestore(&conf->device_lock, flags); conf->raid_disks = mddev->raid_disks = raid_disks; mddev->delta_disks = 0; unfreeze_array(conf); set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); md_wakeup_thread(mddev->thread); mempool_destroy(oldpool); return 0; } static void raid1_quiesce(struct mddev *mddev, int state) { struct r1conf *conf = mddev->private; switch(state) { case 2: /* wake for suspend */ wake_up(&conf->wait_barrier); break; case 1: freeze_array(conf, 0); break; case 0: unfreeze_array(conf); break; } } static void *raid1_takeover(struct mddev *mddev) { /* raid1 can take over: * raid5 with 2 devices, any layout or chunk size */ if (mddev->level == 5 && mddev->raid_disks == 2) { struct r1conf *conf; mddev->new_level = 1; mddev->new_layout = 0; mddev->new_chunk_sectors = 0; conf = setup_conf(mddev); if (!IS_ERR(conf)) /* Array must appear to be quiesced */ conf->array_frozen = 1; return conf; } return ERR_PTR(-EINVAL); } static struct md_personality raid1_personality = { .name = "raid1", .level = 1, .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, .size = raid1_size, .check_reshape = raid1_reshape, .quiesce = raid1_quiesce, .takeover = raid1_takeover, }; static int __init raid_init(void) { return register_md_personality(&raid1_personality); } static void raid_exit(void) { unregister_md_personality(&raid1_personality); } module_init(raid_init); module_exit(raid_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD"); MODULE_ALIAS("md-personality-3"); /* RAID1 */ MODULE_ALIAS("md-raid1"); MODULE_ALIAS("md-level-1"); module_param(max_queued_requests, int, S_IRUGO|S_IWUSR);