diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/raid1.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/md/raid1.c | 2953 |
1 files changed, 0 insertions, 2953 deletions
diff --git a/ANDROID_3.4.5/drivers/md/raid1.c b/ANDROID_3.4.5/drivers/md/raid1.c deleted file mode 100644 index d7e95772..00000000 --- a/ANDROID_3.4.5/drivers/md/raid1.c +++ /dev/null @@ -1,2953 +0,0 @@ -/* - * 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 <miku@iki.fi>, 2000 - * - * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk> - * Various fixes by Neil Brown <neilb@cse.unsw.edu.au> - * - * Changes by Peter T. Breuer <ptb@it.uc3m.es> 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 <linux/slab.h> -#include <linux/delay.h> -#include <linux/blkdev.h> -#include <linux/module.h> -#include <linux/seq_file.h> -#include <linux/ratelimit.h> -#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 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); -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_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(gfp_t gfp_flags, void *data) -{ - struct pool_info *pi = data; - struct page *page; - 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]; - 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; - bio->bi_vcnt = i+1; - } - } - /* If not user-requests, copy the page pointers to all bios */ - if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { - for (i=0; i<RESYNC_PAGES ; i++) - for (j=1; j<pi->raid_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_pages: - for (j=0 ; j < pi->raid_disks; j++) - for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++) - put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page); - j = -1; -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; - - 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); - } 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); - } -} - -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->bi_size >> 9) - 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); - 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); - } - - rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); -} - -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; - 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 + - (mbio->bi_size >> 9) - 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 start_disk; - int best_disk; - int i; - sector_t best_dist; - struct md_rdev *rdev; - int choose_first; - - 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 = MaxSector; - best_good_sectors = 0; - - if (conf->mddev->recovery_cp < MaxSector && - (this_sector + sectors >= conf->next_resync)) { - choose_first = 1; - start_disk = 0; - } else { - choose_first = 0; - start_disk = conf->last_used; - } - - for (i = 0 ; i < conf->raid_disks * 2 ; i++) { - sector_t dist; - sector_t first_bad; - int bad_sectors; - - int disk = start_disk + i; - if (disk >= conf->raid_disks) - disk -= conf->raid_disks; - - 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; - - dist = abs(this_sector - conf->mirrors[disk].head_position); - if (choose_first - /* Don't change to another disk for sequential reads */ - || conf->next_seq_sect == this_sector - || dist == 0 - /* If device is idle, use it */ - || atomic_read(&rdev->nr_pending) == 0) { - best_disk = disk; - break; - } - if (dist < best_dist) { - best_dist = dist; - best_disk = 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; - conf->next_seq_sect = this_sector + sectors; - conf->last_used = best_disk; - } - 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<<BDI_async_congested)) || 1) - ret |= bdi_congested(&q->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; - 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. - */ -#define RESYNC_DEPTH 32 - -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++; - - /* Now wait for all pending IO to complete */ - wait_event_lock_irq(conf->wait_barrier, - !conf->nr_pending && conf->barrier < RESYNC_DEPTH, - 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 void wait_barrier(struct r1conf *conf) -{ - spin_lock_irq(&conf->resync_lock); - if (conf->barrier) { - 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->barrier || - (conf->nr_pending && - current->bio_list && - !bio_list_empty(current->bio_list)), - conf->resync_lock, - ); - conf->nr_waiting--; - } - conf->nr_pending++; - spin_unlock_irq(&conf->resync_lock); -} - -static void allow_barrier(struct r1conf *conf) -{ - unsigned long flags; - spin_lock_irqsave(&conf->resync_lock, flags); - conf->nr_pending--; - spin_unlock_irqrestore(&conf->resync_lock, flags); - wake_up(&conf->wait_barrier); -} - -static void freeze_array(struct r1conf *conf) -{ - /* stop syncio and normal IO and wait for everything to - * go quite. - * We increment barrier and nr_waiting, and then - * wait until nr_pending match nr_queued+1 - * 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 (1) - * must match the number of pending IOs (nr_pending) before - * we continue. - */ - spin_lock_irq(&conf->resync_lock); - conf->barrier++; - conf->nr_waiting++; - wait_event_lock_irq(conf->wait_barrier, - conf->nr_pending == conf->nr_queued+1, - 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->barrier--; - conf->nr_waiting--; - 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(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); -} - -static void make_request(struct mddev *mddev, struct bio * bio) -{ - struct r1conf *conf = mddev->private; - struct mirror_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)); - struct md_rdev *blocked_rdev; - int plugged; - int first_clone; - int sectors_handled; - int max_sectors; - - /* - * 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->bi_sector + bio->bi_size/512 > 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->bi_sector + bio->bi_size/512 <= mddev->suspend_lo || - bio->bi_sector >= mddev->suspend_hi) - break; - schedule(); - } - finish_wait(&conf->wait_barrier, &w); - } - - wait_barrier(conf); - - 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->bi_size >> 9; - 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->bi_size >> 9) - 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. - */ - plugged = mddev_check_plugged(mddev); - - disks = conf->raid_disks * 2; - retry_write: - 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; - - 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); - md_wait_for_blocked_rdev(blocked_rdev, mddev); - wait_barrier(conf); - 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; - - /* Yes, I really want the '__' version so that - * we clear any unused pointer in the io_vec, rather - * than leave them unchanged. This is important - * because when we come to free the pages, we won't - * know the original bi_idx, so we just free - * them all - */ - __bio_for_each_segment(bvec, mbio, j, 0) - 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; - mbio->bi_private = r1_bio; - - atomic_inc(&r1_bio->remaining); - spin_lock_irqsave(&conf->device_lock, flags); - bio_list_add(&conf->pending_bio_list, mbio); - conf->pending_count++; - spin_unlock_irqrestore(&conf->device_lock, flags); - } - /* Mustn't call r1_bio_write_done before this next test, - * as it could result in the bio being freed. - */ - if (sectors_handled < (bio->bi_size >> 9)) { - 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->bi_size >> 9) - 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); - - if (do_sync || !bitmap || !plugged) - md_wakeup_thread(mddev->thread); -} - -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); - allow_barrier(conf); - - mempool_destroy(conf->r1buf_pool); - conf->r1buf_pool = NULL; -} - -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 - && !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 mirror_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) { - - 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(); - raise_barrier(conf); - lower_barrier(conf); - clear_bit(Unmerged, &rdev->flags); - } - md_integrity_add_rdev(rdev, mddev); - 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 mirror_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; - raise_barrier(conf); - clear_bit(Replacement, &repl->flags); - p->rdev = repl; - conf->mirrors[conf->raid_disks + number].rdev = NULL; - lower_barrier(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; - - 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; - vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9); - 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]; - int size; - - if (r1_bio->bios[i]->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) - mddev->resync_mismatches += r1_bio->sectors; - 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; - } - /* fixup the bio for reuse */ - sbio->bi_vcnt = vcnt; - sbio->bi_size = r1_bio->sectors << 9; - sbio->bi_idx = 0; - sbio->bi_phys_segments = 0; - sbio->bi_flags &= ~(BIO_POOL_MASK - 1); - sbio->bi_flags |= 1 << BIO_UPTODATE; - sbio->bi_next = NULL; - sbio->bi_sector = r1_bio->sector + - conf->mirrors[i].rdev->data_offset; - sbio->bi_bdev = conf->mirrors[i].rdev->bdev; - size = sbio->bi_size; - for (j = 0; j < vcnt ; j++) { - struct bio_vec *bi; - bi = &sbio->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; - memcpy(page_address(bi->bv_page), - page_address(pbio->bi_io_vec[j].bv_page), - PAGE_SIZE); - } - } - 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, 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 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) && - 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 void bi_complete(struct bio *bio, int error) -{ - complete((struct completion *)bio->bi_private); -} - -static int submit_bio_wait(int rw, struct bio *bio) -{ - struct completion event; - rw |= REQ_SYNC; - - init_completion(&event); - bio->bi_private = &event; - bio->bi_end_io = bi_complete; - submit_bio(rw, bio); - wait_for_completion(&event); - - return test_bit(BIO_UPTODATE, &bio->bi_flags); -} - -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; - int vcnt, idx; - struct bio_vec *vec; - - /* 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; - - if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { - vcnt = r1_bio->behind_page_count; - vec = r1_bio->behind_bvecs; - idx = 0; - while (vec[idx].bv_page == NULL) - idx++; - } else { - vcnt = r1_bio->master_bio->bi_vcnt; - vec = r1_bio->master_bio->bi_io_vec; - idx = r1_bio->master_bio->bi_idx; - } - while (sect_to_write) { - struct bio *wbio; - if (sectors > sect_to_write) - sectors = sect_to_write; - /* Write at 'sector' for 'sectors'*/ - - wbio = bio_alloc_mddev(GFP_NOIO, vcnt, mddev); - memcpy(wbio->bi_io_vec, vec, vcnt * sizeof(struct bio_vec)); - wbio->bi_sector = r1_bio->sector; - wbio->bi_rw = WRITE; - wbio->bi_vcnt = vcnt; - wbio->bi_size = r1_bio->sectors << 9; - wbio->bi_idx = idx; - - 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); - } - 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); - 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); - 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); - - 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 = (mbio->bi_size >> 9) - - 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 mddev *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 (;;) { - - if (atomic_read(&mddev->plug_cnt) == 0) - 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<<MD_CHANGE_PENDING)) - md_check_recovery(mddev); - } - blk_finish_plug(&plug); -} - - -static int init_resync(struct r1conf *conf) -{ - int buffs; - - buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; - BUG_ON(conf->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]; - - /* take from bio_init */ - bio->bi_next = NULL; - bio->bi_flags &= ~(BIO_POOL_MASK-1); - bio->bi_flags |= 1 << BIO_UPTODATE; - bio->bi_rw = READ; - bio->bi_vcnt = 0; - bio->bi_idx = 0; - bio->bi_phys_segments = 0; - bio->bi_size = 0; - bio->bi_end_io = NULL; - bio->bi_private = NULL; - - 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++; - } - } - 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 = 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; i++) { - bio = r1_bio->bios[i]; - if (bio->bi_end_io == end_sync_read) { - 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 mirror_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 mirror_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 + conf->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; - } - 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; - - err = -EIO; - conf->last_used = -1; - 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) - conf->fullsync = 1; - } else if (conf->last_used < 0) - /* - * The first working device is used as a - * starting point to read balancing. - */ - conf->last_used = i; - } - - if (conf->last_used < 0) { - printk(KERN_ERR "md/raid1:%s: no operational mirrors\n", - mdname(mddev)); - goto abort; - } - err = -ENOMEM; - conf->thread = md_register_thread(raid1d, mddev, NULL); - 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; - - 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); - - rdev_for_each(rdev, mddev) { - if (!mddev->gendisk) - continue; - disk_stack_limits(mddev->gendisk, rdev->bdev, - rdev->data_offset << 9); - } - - 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); - } - - 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); - } - - raise_barrier(conf); - lower_barrier(conf); - - md_unregister_thread(&mddev->thread); - 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(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. - */ - md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0)); - if (mddev->array_sectors > raid1_size(mddev, sectors, 0)) - return -EINVAL; - 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 mirror_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 mirror_info) * raid_disks * 2, - GFP_KERNEL); - if (!newmirrors) { - kfree(newpoolinfo); - mempool_destroy(newpool); - return -ENOMEM; - } - - raise_barrier(conf); - - /* 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; - - conf->last_used = 0; /* just make sure it is in-range */ - lower_barrier(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: - raise_barrier(conf); - break; - case 0: - lower_barrier(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)) - conf->barrier = 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); |