diff options
Diffstat (limited to 'drivers/md/raid1.c')
| -rw-r--r-- | drivers/md/raid1.c | 3421 |
1 files changed, 3421 insertions, 0 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c new file mode 100644 index 000000000..911670273 --- /dev/null +++ b/drivers/md/raid1.c @@ -0,0 +1,3421 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 + */ + +#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 <linux/interval_tree_generic.h> + +#include <trace/events/block.h> + +#include "md.h" +#include "raid1.h" +#include "md-bitmap.h" + +#define UNSUPPORTED_MDDEV_FLAGS \ + ((1L << MD_HAS_JOURNAL) | \ + (1L << MD_JOURNAL_CLEAN) | \ + (1L << MD_HAS_PPL) | \ + (1L << MD_HAS_MULTIPLE_PPLS)) + +static void allow_barrier(struct r1conf *conf, sector_t sector_nr); +static void lower_barrier(struct r1conf *conf, sector_t sector_nr); + +#define raid1_log(md, fmt, args...) \ + do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0) + +#include "raid1-10.c" + +#define START(node) ((node)->start) +#define LAST(node) ((node)->last) +INTERVAL_TREE_DEFINE(struct serial_info, node, sector_t, _subtree_last, + START, LAST, static inline, raid1_rb); + +static int check_and_add_serial(struct md_rdev *rdev, struct r1bio *r1_bio, + struct serial_info *si, int idx) +{ + unsigned long flags; + int ret = 0; + sector_t lo = r1_bio->sector; + sector_t hi = lo + r1_bio->sectors; + struct serial_in_rdev *serial = &rdev->serial[idx]; + + spin_lock_irqsave(&serial->serial_lock, flags); + /* collision happened */ + if (raid1_rb_iter_first(&serial->serial_rb, lo, hi)) + ret = -EBUSY; + else { + si->start = lo; + si->last = hi; + raid1_rb_insert(si, &serial->serial_rb); + } + spin_unlock_irqrestore(&serial->serial_lock, flags); + + return ret; +} + +static void wait_for_serialization(struct md_rdev *rdev, struct r1bio *r1_bio) +{ + struct mddev *mddev = rdev->mddev; + struct serial_info *si; + int idx = sector_to_idx(r1_bio->sector); + struct serial_in_rdev *serial = &rdev->serial[idx]; + + if (WARN_ON(!mddev->serial_info_pool)) + return; + si = mempool_alloc(mddev->serial_info_pool, GFP_NOIO); + wait_event(serial->serial_io_wait, + check_and_add_serial(rdev, r1_bio, si, idx) == 0); +} + +static void remove_serial(struct md_rdev *rdev, sector_t lo, sector_t hi) +{ + struct serial_info *si; + unsigned long flags; + int found = 0; + struct mddev *mddev = rdev->mddev; + int idx = sector_to_idx(lo); + struct serial_in_rdev *serial = &rdev->serial[idx]; + + spin_lock_irqsave(&serial->serial_lock, flags); + for (si = raid1_rb_iter_first(&serial->serial_rb, lo, hi); + si; si = raid1_rb_iter_next(si, lo, hi)) { + if (si->start == lo && si->last == hi) { + raid1_rb_remove(si, &serial->serial_rb); + mempool_free(si, mddev->serial_info_pool); + found = 1; + break; + } + } + if (!found) + WARN(1, "The write IO is not recorded for serialization\n"); + spin_unlock_irqrestore(&serial->serial_lock, flags); + wake_up(&serial->serial_io_wait); +} + +/* + * for resync bio, r1bio pointer can be retrieved from the per-bio + * 'struct resync_pages'. + */ +static inline struct r1bio *get_resync_r1bio(struct bio *bio) +{ + return get_resync_pages(bio)->raid_bio; +} + +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); +} + +#define RESYNC_DEPTH 32 +#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) +#define RESYNC_WINDOW (RESYNC_BLOCK_SIZE * RESYNC_DEPTH) +#define RESYNC_WINDOW_SECTORS (RESYNC_WINDOW >> 9) +#define CLUSTER_RESYNC_WINDOW (16 * RESYNC_WINDOW) +#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9) + +static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) +{ + struct pool_info *pi = data; + struct r1bio *r1_bio; + struct bio *bio; + int need_pages; + int j; + struct resync_pages *rps; + + r1_bio = r1bio_pool_alloc(gfp_flags, pi); + if (!r1_bio) + return NULL; + + rps = kmalloc_array(pi->raid_disks, sizeof(struct resync_pages), + gfp_flags); + if (!rps) + goto out_free_r1bio; + + /* + * Allocate bios : 1 for reading, n-1 for writing + */ + for (j = pi->raid_disks ; j-- ; ) { + bio = bio_kmalloc(RESYNC_PAGES, gfp_flags); + if (!bio) + goto out_free_bio; + bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0); + 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)) + need_pages = pi->raid_disks; + else + need_pages = 1; + for (j = 0; j < pi->raid_disks; j++) { + struct resync_pages *rp = &rps[j]; + + bio = r1_bio->bios[j]; + + if (j < need_pages) { + if (resync_alloc_pages(rp, gfp_flags)) + goto out_free_pages; + } else { + memcpy(rp, &rps[0], sizeof(*rp)); + resync_get_all_pages(rp); + } + + rp->raid_bio = r1_bio; + bio->bi_private = rp; + } + + r1_bio->master_bio = NULL; + + return r1_bio; + +out_free_pages: + while (--j >= 0) + resync_free_pages(&rps[j]); + +out_free_bio: + while (++j < pi->raid_disks) { + bio_uninit(r1_bio->bios[j]); + kfree(r1_bio->bios[j]); + } + kfree(rps); + +out_free_r1bio: + rbio_pool_free(r1_bio, data); + return NULL; +} + +static void r1buf_pool_free(void *__r1_bio, void *data) +{ + struct pool_info *pi = data; + int i; + struct r1bio *r1bio = __r1_bio; + struct resync_pages *rp = NULL; + + for (i = pi->raid_disks; i--; ) { + rp = get_resync_pages(r1bio->bios[i]); + resync_free_pages(rp); + bio_uninit(r1bio->bios[i]); + kfree(r1bio->bios[i]); + } + + /* resync pages array stored in the 1st bio's .bi_private */ + kfree(rp); + + rbio_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; + sector_t sect = r1_bio->sector; + 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, sect); +} + +static void reschedule_retry(struct r1bio *r1_bio) +{ + unsigned long flags; + struct mddev *mddev = r1_bio->mddev; + struct r1conf *conf = mddev->private; + int idx; + + idx = sector_to_idx(r1_bio->sector); + spin_lock_irqsave(&conf->device_lock, flags); + list_add(&r1_bio->retry_list, &conf->retry_list); + atomic_inc(&conf->nr_queued[idx]); + 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; + + if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) + bio->bi_status = BLK_STS_IOERR; + + bio_endio(bio); +} + +static void raid_end_bio_io(struct r1bio *r1_bio) +{ + struct bio *bio = r1_bio->master_bio; + struct r1conf *conf = r1_bio->mddev->private; + sector_t sector = r1_bio->sector; + + /* 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_iter.bi_sector, + (unsigned long long) bio_end_sector(bio) - 1); + + call_bio_endio(r1_bio); + } + + free_r1bio(r1_bio); + /* + * Wake up any possible resync thread that waits for the device + * to go idle. All I/Os, even write-behind writes, are done. + */ + allow_barrier(conf, sector); +} + +/* + * 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 uptodate = !bio->bi_status; + struct r1bio *r1_bio = bio->bi_private; + struct r1conf *conf = r1_bio->mddev->private; + struct md_rdev *rdev = conf->mirrors[r1_bio->read_disk].rdev; + + /* + * this branch is our 'one mirror IO has finished' event handler: + */ + update_head_pos(r1_bio->read_disk, r1_bio); + + if (uptodate) + set_bit(R1BIO_Uptodate, &r1_bio->state); + else if (test_bit(FailFast, &rdev->flags) && + test_bit(R1BIO_FailFast, &r1_bio->state)) + /* This was a fail-fast read so we definitely + * want to retry */ + ; + 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(In_sync, &rdev->flags))) + uptodate = 1; + spin_unlock_irqrestore(&conf->device_lock, flags); + } + + if (uptodate) { + raid_end_bio_io(r1_bio); + rdev_dec_pending(rdev, conf->mddev); + } else { + /* + * oops, read error: + */ + pr_err_ratelimited("md/raid1:%s: %pg: rescheduling sector %llu\n", + mdname(conf->mddev), + rdev->bdev, + (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)) { + bio_free_pages(r1_bio->behind_master_bio); + bio_put(r1_bio->behind_master_bio); + r1_bio->behind_master_bio = NULL; + } + /* clear the bitmap if all writes complete successfully */ + md_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) +{ + struct r1bio *r1_bio = bio->bi_private; + int behind = test_bit(R1BIO_BehindIO, &r1_bio->state); + struct r1conf *conf = r1_bio->mddev->private; + struct bio *to_put = NULL; + int mirror = find_bio_disk(r1_bio, bio); + struct md_rdev *rdev = conf->mirrors[mirror].rdev; + bool discard_error; + sector_t lo = r1_bio->sector; + sector_t hi = r1_bio->sector + r1_bio->sectors; + + discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD; + + /* + * 'one mirror IO has finished' event handler: + */ + if (bio->bi_status && !discard_error) { + set_bit(WriteErrorSeen, &rdev->flags); + if (!test_and_set_bit(WantReplacement, &rdev->flags)) + set_bit(MD_RECOVERY_NEEDED, & + conf->mddev->recovery); + + if (test_bit(FailFast, &rdev->flags) && + (bio->bi_opf & MD_FAILFAST) && + /* We never try FailFast to WriteMostly devices */ + !test_bit(WriteMostly, &rdev->flags)) { + md_error(r1_bio->mddev, rdev); + } + + /* + * When the device is faulty, it is not necessary to + * handle write error. + */ + if (!test_bit(Faulty, &rdev->flags)) + set_bit(R1BIO_WriteError, &r1_bio->state); + else { + /* Fail the request */ + set_bit(R1BIO_Degraded, &r1_bio->state); + /* Finished with this branch */ + r1_bio->bios[mirror] = NULL; + to_put = bio; + } + } 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, &rdev->flags) && + !test_bit(Faulty, &rdev->flags)) + set_bit(R1BIO_Uptodate, &r1_bio->state); + + /* Maybe we can clear some bad blocks. */ + if (is_badblock(rdev, r1_bio->sector, r1_bio->sectors, + &first_bad, &bad_sectors) && !discard_error) { + r1_bio->bios[mirror] = IO_MADE_GOOD; + set_bit(R1BIO_MadeGood, &r1_bio->state); + } + } + + if (behind) { + if (test_bit(CollisionCheck, &rdev->flags)) + remove_serial(rdev, lo, hi); + if (test_bit(WriteMostly, &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_iter.bi_sector, + (unsigned long long) bio_end_sector(mbio) - 1); + call_bio_endio(r1_bio); + } + } + } else if (rdev->mddev->serialize_policy) + remove_serial(rdev, lo, hi); + if (r1_bio->bios[mirror] == NULL) + rdev_dec_pending(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); +} + +static sector_t align_to_barrier_unit_end(sector_t start_sector, + sector_t sectors) +{ + sector_t len; + + WARN_ON(sectors == 0); + /* + * len is the number of sectors from start_sector to end of the + * barrier unit which start_sector belongs to. + */ + len = round_up(start_sector + 1, BARRIER_UNIT_SECTOR_SIZE) - + start_sector; + + if (len > sectors) + len = sectors; + + return len; +} + +/* + * 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; + clear_bit(R1BIO_FailFast, &r1_bio->state); + + if ((conf->mddev->recovery_cp < this_sector + sectors) || + (mddev_is_clustered(conf->mddev) && + md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector, + this_sector + sectors))) + 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(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_dist_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_dist_disk = disk; + best_pending_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 { + if ((sectors > best_good_sectors) && (best_disk >= 0)) + best_disk = -1; + best_good_sectors = sectors; + } + + if (best_disk >= 0) + /* At least two disks to choose from so failfast is OK */ + set_bit(R1BIO_FailFast, &r1_bio->state); + + nonrot = bdev_nonrot(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 (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 || min_pending == 0) + 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); + 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 void wake_up_barrier(struct r1conf *conf) +{ + if (wq_has_sleeper(&conf->wait_barrier)) + wake_up(&conf->wait_barrier); +} + +static void flush_bio_list(struct r1conf *conf, struct bio *bio) +{ + /* flush any pending bitmap writes to disk before proceeding w/ I/O */ + raid1_prepare_flush_writes(conf->mddev->bitmap); + wake_up_barrier(conf); + + while (bio) { /* submit pending writes */ + struct bio *next = bio->bi_next; + + raid1_submit_write(bio); + bio = next; + cond_resched(); + } +} + +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 blk_plug plug; + struct bio *bio; + + bio = bio_list_get(&conf->pending_bio_list); + spin_unlock_irq(&conf->device_lock); + + /* + * As this is called in a wait_event() loop (see freeze_array), + * current->state might be TASK_UNINTERRUPTIBLE which will + * cause a warning when we prepare to wait again. As it is + * rare that this path is taken, it is perfectly safe to force + * us to go around the wait_event() loop again, so the warning + * is a false-positive. Silence the warning by resetting + * thread state + */ + __set_current_state(TASK_RUNNING); + blk_start_plug(&plug); + flush_bio_list(conf, bio); + blk_finish_plug(&plug); + } 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. + * + * If resync/recovery is interrupted, returns -EINTR; + * Otherwise, returns 0. + */ +static int raise_barrier(struct r1conf *conf, sector_t sector_nr) +{ + int idx = sector_to_idx(sector_nr); + + spin_lock_irq(&conf->resync_lock); + + /* Wait until no block IO is waiting */ + wait_event_lock_irq(conf->wait_barrier, + !atomic_read(&conf->nr_waiting[idx]), + conf->resync_lock); + + /* block any new IO from starting */ + atomic_inc(&conf->barrier[idx]); + /* + * In raise_barrier() we firstly increase conf->barrier[idx] then + * check conf->nr_pending[idx]. In _wait_barrier() we firstly + * increase conf->nr_pending[idx] then check conf->barrier[idx]. + * A memory barrier here to make sure conf->nr_pending[idx] won't + * be fetched before conf->barrier[idx] is increased. Otherwise + * there will be a race between raise_barrier() and _wait_barrier(). + */ + smp_mb__after_atomic(); + + /* For these conditions we must wait: + * A: while the array is in frozen state + * B: while conf->nr_pending[idx] is not 0, meaning regular I/O + * existing in corresponding I/O barrier bucket. + * C: while conf->barrier[idx] >= RESYNC_DEPTH, meaning reaches + * max resync count which allowed on current I/O barrier bucket. + */ + wait_event_lock_irq(conf->wait_barrier, + (!conf->array_frozen && + !atomic_read(&conf->nr_pending[idx]) && + atomic_read(&conf->barrier[idx]) < RESYNC_DEPTH) || + test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery), + conf->resync_lock); + + if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) { + atomic_dec(&conf->barrier[idx]); + spin_unlock_irq(&conf->resync_lock); + wake_up(&conf->wait_barrier); + return -EINTR; + } + + atomic_inc(&conf->nr_sync_pending); + spin_unlock_irq(&conf->resync_lock); + + return 0; +} + +static void lower_barrier(struct r1conf *conf, sector_t sector_nr) +{ + int idx = sector_to_idx(sector_nr); + + BUG_ON(atomic_read(&conf->barrier[idx]) <= 0); + + atomic_dec(&conf->barrier[idx]); + atomic_dec(&conf->nr_sync_pending); + wake_up(&conf->wait_barrier); +} + +static bool _wait_barrier(struct r1conf *conf, int idx, bool nowait) +{ + bool ret = true; + + /* + * We need to increase conf->nr_pending[idx] very early here, + * then raise_barrier() can be blocked when it waits for + * conf->nr_pending[idx] to be 0. Then we can avoid holding + * conf->resync_lock when there is no barrier raised in same + * barrier unit bucket. Also if the array is frozen, I/O + * should be blocked until array is unfrozen. + */ + atomic_inc(&conf->nr_pending[idx]); + /* + * In _wait_barrier() we firstly increase conf->nr_pending[idx], then + * check conf->barrier[idx]. In raise_barrier() we firstly increase + * conf->barrier[idx], then check conf->nr_pending[idx]. A memory + * barrier is necessary here to make sure conf->barrier[idx] won't be + * fetched before conf->nr_pending[idx] is increased. Otherwise there + * will be a race between _wait_barrier() and raise_barrier(). + */ + smp_mb__after_atomic(); + + /* + * Don't worry about checking two atomic_t variables at same time + * here. If during we check conf->barrier[idx], the array is + * frozen (conf->array_frozen is 1), and chonf->barrier[idx] is + * 0, it is safe to return and make the I/O continue. Because the + * array is frozen, all I/O returned here will eventually complete + * or be queued, no race will happen. See code comment in + * frozen_array(). + */ + if (!READ_ONCE(conf->array_frozen) && + !atomic_read(&conf->barrier[idx])) + return ret; + + /* + * After holding conf->resync_lock, conf->nr_pending[idx] + * should be decreased before waiting for barrier to drop. + * Otherwise, we may encounter a race condition because + * raise_barrer() might be waiting for conf->nr_pending[idx] + * to be 0 at same time. + */ + spin_lock_irq(&conf->resync_lock); + atomic_inc(&conf->nr_waiting[idx]); + atomic_dec(&conf->nr_pending[idx]); + /* + * In case freeze_array() is waiting for + * get_unqueued_pending() == extra + */ + wake_up_barrier(conf); + /* Wait for the barrier in same barrier unit bucket to drop. */ + + /* Return false when nowait flag is set */ + if (nowait) { + ret = false; + } else { + wait_event_lock_irq(conf->wait_barrier, + !conf->array_frozen && + !atomic_read(&conf->barrier[idx]), + conf->resync_lock); + atomic_inc(&conf->nr_pending[idx]); + } + + atomic_dec(&conf->nr_waiting[idx]); + spin_unlock_irq(&conf->resync_lock); + return ret; +} + +static bool wait_read_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait) +{ + int idx = sector_to_idx(sector_nr); + bool ret = true; + + /* + * Very similar to _wait_barrier(). The difference is, for read + * I/O we don't need wait for sync I/O, but if the whole array + * is frozen, the read I/O still has to wait until the array is + * unfrozen. Since there is no ordering requirement with + * conf->barrier[idx] here, memory barrier is unnecessary as well. + */ + atomic_inc(&conf->nr_pending[idx]); + + if (!READ_ONCE(conf->array_frozen)) + return ret; + + spin_lock_irq(&conf->resync_lock); + atomic_inc(&conf->nr_waiting[idx]); + atomic_dec(&conf->nr_pending[idx]); + /* + * In case freeze_array() is waiting for + * get_unqueued_pending() == extra + */ + wake_up_barrier(conf); + /* Wait for array to be unfrozen */ + + /* Return false when nowait flag is set */ + if (nowait) { + /* Return false when nowait flag is set */ + ret = false; + } else { + wait_event_lock_irq(conf->wait_barrier, + !conf->array_frozen, + conf->resync_lock); + atomic_inc(&conf->nr_pending[idx]); + } + + atomic_dec(&conf->nr_waiting[idx]); + spin_unlock_irq(&conf->resync_lock); + return ret; +} + +static bool wait_barrier(struct r1conf *conf, sector_t sector_nr, bool nowait) +{ + int idx = sector_to_idx(sector_nr); + + return _wait_barrier(conf, idx, nowait); +} + +static void _allow_barrier(struct r1conf *conf, int idx) +{ + atomic_dec(&conf->nr_pending[idx]); + wake_up_barrier(conf); +} + +static void allow_barrier(struct r1conf *conf, sector_t sector_nr) +{ + int idx = sector_to_idx(sector_nr); + + _allow_barrier(conf, idx); +} + +/* conf->resync_lock should be held */ +static int get_unqueued_pending(struct r1conf *conf) +{ + int idx, ret; + + ret = atomic_read(&conf->nr_sync_pending); + for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) + ret += atomic_read(&conf->nr_pending[idx]) - + atomic_read(&conf->nr_queued[idx]); + + return ret; +} + +static void freeze_array(struct r1conf *conf, int extra) +{ + /* Stop sync I/O and normal I/O and wait for everything to + * go quiet. + * This is called in two situations: + * 1) management command handlers (reshape, remove disk, quiesce). + * 2) one normal I/O request failed. + + * After array_frozen is set to 1, new sync IO will be blocked at + * raise_barrier(), and new normal I/O will blocked at _wait_barrier() + * or wait_read_barrier(). The flying I/Os will either complete or be + * queued. When everything goes quite, there are only queued I/Os left. + + * Every flying I/O contributes to a conf->nr_pending[idx], idx is the + * barrier bucket index which this I/O request hits. When all sync and + * normal I/O are queued, sum of all conf->nr_pending[] will match sum + * of all conf->nr_queued[]. But normal I/O failure is an exception, + * in handle_read_error(), we may call freeze_array() before trying to + * fix the read error. In this case, the error read I/O is not queued, + * so get_unqueued_pending() == 1. + * + * Therefore before this function returns, we need to wait until + * get_unqueued_pendings(conf) gets equal to extra. For + * normal I/O context, extra is 1, in rested situations extra is 0. + */ + spin_lock_irq(&conf->resync_lock); + conf->array_frozen = 1; + raid1_log(conf->mddev, "wait freeze"); + wait_event_lock_irq_cmd( + conf->wait_barrier, + get_unqueued_pending(conf) == 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; + spin_unlock_irq(&conf->resync_lock); + wake_up(&conf->wait_barrier); +} + +static void alloc_behind_master_bio(struct r1bio *r1_bio, + struct bio *bio) +{ + int size = bio->bi_iter.bi_size; + unsigned vcnt = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; + int i = 0; + struct bio *behind_bio = NULL; + + behind_bio = bio_alloc_bioset(NULL, vcnt, 0, GFP_NOIO, + &r1_bio->mddev->bio_set); + if (!behind_bio) + return; + + /* discard op, we don't support writezero/writesame yet */ + if (!bio_has_data(bio)) { + behind_bio->bi_iter.bi_size = size; + goto skip_copy; + } + + while (i < vcnt && size) { + struct page *page; + int len = min_t(int, PAGE_SIZE, size); + + page = alloc_page(GFP_NOIO); + if (unlikely(!page)) + goto free_pages; + + if (!bio_add_page(behind_bio, page, len, 0)) { + put_page(page); + goto free_pages; + } + + size -= len; + i++; + } + + bio_copy_data(behind_bio, bio); +skip_copy: + r1_bio->behind_master_bio = behind_bio; + set_bit(R1BIO_BehindIO, &r1_bio->state); + + return; + +free_pages: + pr_debug("%dB behind alloc failed, doing sync I/O\n", + bio->bi_iter.bi_size); + bio_free_pages(behind_bio); + bio_put(behind_bio); +} + +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) { + spin_lock_irq(&conf->device_lock); + bio_list_merge(&conf->pending_bio_list, &plug->pending); + spin_unlock_irq(&conf->device_lock); + wake_up_barrier(conf); + 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); + flush_bio_list(conf, bio); + kfree(plug); +} + +static void init_r1bio(struct r1bio *r1_bio, struct mddev *mddev, struct bio *bio) +{ + r1_bio->master_bio = bio; + r1_bio->sectors = bio_sectors(bio); + r1_bio->state = 0; + r1_bio->mddev = mddev; + r1_bio->sector = bio->bi_iter.bi_sector; +} + +static inline struct r1bio * +alloc_r1bio(struct mddev *mddev, struct bio *bio) +{ + struct r1conf *conf = mddev->private; + struct r1bio *r1_bio; + + r1_bio = mempool_alloc(&conf->r1bio_pool, GFP_NOIO); + /* Ensure no bio records IO_BLOCKED */ + memset(r1_bio->bios, 0, conf->raid_disks * sizeof(r1_bio->bios[0])); + init_r1bio(r1_bio, mddev, bio); + return r1_bio; +} + +static void raid1_read_request(struct mddev *mddev, struct bio *bio, + int max_read_sectors, struct r1bio *r1_bio) +{ + struct r1conf *conf = mddev->private; + struct raid1_info *mirror; + struct bio *read_bio; + struct bitmap *bitmap = mddev->bitmap; + const enum req_op op = bio_op(bio); + const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC; + int max_sectors; + int rdisk; + bool r1bio_existed = !!r1_bio; + char b[BDEVNAME_SIZE]; + + /* + * If r1_bio is set, we are blocking the raid1d thread + * so there is a tiny risk of deadlock. So ask for + * emergency memory if needed. + */ + gfp_t gfp = r1_bio ? (GFP_NOIO | __GFP_HIGH) : GFP_NOIO; + + if (r1bio_existed) { + /* Need to get the block device name carefully */ + struct md_rdev *rdev; + rcu_read_lock(); + rdev = rcu_dereference(conf->mirrors[r1_bio->read_disk].rdev); + if (rdev) + snprintf(b, sizeof(b), "%pg", rdev->bdev); + else + strcpy(b, "???"); + rcu_read_unlock(); + } + + /* + * Still need barrier for READ in case that whole + * array is frozen. + */ + if (!wait_read_barrier(conf, bio->bi_iter.bi_sector, + bio->bi_opf & REQ_NOWAIT)) { + bio_wouldblock_error(bio); + return; + } + + if (!r1_bio) + r1_bio = alloc_r1bio(mddev, bio); + else + init_r1bio(r1_bio, mddev, bio); + r1_bio->sectors = max_read_sectors; + + /* + * make_request() can abort the operation when read-ahead is being + * used and no empty request is available. + */ + rdisk = read_balance(conf, r1_bio, &max_sectors); + + if (rdisk < 0) { + /* couldn't find anywhere to read from */ + if (r1bio_existed) { + pr_crit_ratelimited("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); + return; + } + mirror = conf->mirrors + rdisk; + + if (r1bio_existed) + pr_info_ratelimited("md/raid1:%s: redirecting sector %llu to other mirror: %pg\n", + mdname(mddev), + (unsigned long long)r1_bio->sector, + mirror->rdev->bdev); + + 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' + */ + raid1_log(mddev, "wait behind writes"); + wait_event(bitmap->behind_wait, + atomic_read(&bitmap->behind_writes) == 0); + } + + if (max_sectors < bio_sectors(bio)) { + struct bio *split = bio_split(bio, max_sectors, + gfp, &conf->bio_split); + bio_chain(split, bio); + submit_bio_noacct(bio); + bio = split; + r1_bio->master_bio = bio; + r1_bio->sectors = max_sectors; + } + + r1_bio->read_disk = rdisk; + if (!r1bio_existed) { + md_account_bio(mddev, &bio); + r1_bio->master_bio = bio; + } + read_bio = bio_alloc_clone(mirror->rdev->bdev, bio, gfp, + &mddev->bio_set); + + r1_bio->bios[rdisk] = read_bio; + + read_bio->bi_iter.bi_sector = r1_bio->sector + + mirror->rdev->data_offset; + read_bio->bi_end_io = raid1_end_read_request; + read_bio->bi_opf = op | do_sync; + if (test_bit(FailFast, &mirror->rdev->flags) && + test_bit(R1BIO_FailFast, &r1_bio->state)) + read_bio->bi_opf |= MD_FAILFAST; + read_bio->bi_private = r1_bio; + + if (mddev->gendisk) + trace_block_bio_remap(read_bio, disk_devt(mddev->gendisk), + r1_bio->sector); + + submit_bio_noacct(read_bio); +} + +static void raid1_write_request(struct mddev *mddev, struct bio *bio, + int max_write_sectors) +{ + struct r1conf *conf = mddev->private; + struct r1bio *r1_bio; + int i, disks; + struct bitmap *bitmap = mddev->bitmap; + unsigned long flags; + struct md_rdev *blocked_rdev; + int first_clone; + int max_sectors; + bool write_behind = false; + + if (mddev_is_clustered(mddev) && + md_cluster_ops->area_resyncing(mddev, WRITE, + bio->bi_iter.bi_sector, bio_end_sector(bio))) { + + DEFINE_WAIT(w); + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } + for (;;) { + prepare_to_wait(&conf->wait_barrier, + &w, TASK_IDLE); + if (!md_cluster_ops->area_resyncing(mddev, WRITE, + bio->bi_iter.bi_sector, + bio_end_sector(bio))) + break; + schedule(); + } + finish_wait(&conf->wait_barrier, &w); + } + + /* + * 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. + */ + if (!wait_barrier(conf, bio->bi_iter.bi_sector, + bio->bi_opf & REQ_NOWAIT)) { + bio_wouldblock_error(bio); + return; + } + + retry_write: + r1_bio = alloc_r1bio(mddev, bio); + r1_bio->sectors = max_write_sectors; + + /* 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; + 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); + + /* + * The write-behind io is only attempted on drives marked as + * write-mostly, which means we could allocate write behind + * bio later. + */ + if (rdev && test_bit(WriteMostly, &rdev->flags)) + write_behind = true; + + 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)) { + 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); + free_r1bio(r1_bio); + allow_barrier(conf, bio->bi_iter.bi_sector); + + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return; + } + raid1_log(mddev, "wait rdev %d blocked", blocked_rdev->raid_disk); + md_wait_for_blocked_rdev(blocked_rdev, mddev); + wait_barrier(conf, bio->bi_iter.bi_sector, false); + goto retry_write; + } + + /* + * When using a bitmap, we may call alloc_behind_master_bio below. + * alloc_behind_master_bio allocates a copy of the data payload a page + * at a time and thus needs a new bio that can fit the whole payload + * this bio in page sized chunks. + */ + if (write_behind && bitmap) + max_sectors = min_t(int, max_sectors, + BIO_MAX_VECS * (PAGE_SIZE >> 9)); + if (max_sectors < bio_sectors(bio)) { + struct bio *split = bio_split(bio, max_sectors, + GFP_NOIO, &conf->bio_split); + bio_chain(split, bio); + submit_bio_noacct(bio); + bio = split; + r1_bio->master_bio = bio; + r1_bio->sectors = max_sectors; + } + + md_account_bio(mddev, &bio); + r1_bio->master_bio = bio; + 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 = NULL; + struct md_rdev *rdev = conf->mirrors[i].rdev; + if (!r1_bio->bios[i]) + continue; + + 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 && write_behind && + (atomic_read(&bitmap->behind_writes) + < mddev->bitmap_info.max_write_behind) && + !waitqueue_active(&bitmap->behind_wait)) { + alloc_behind_master_bio(r1_bio, bio); + } + + md_bitmap_startwrite(bitmap, r1_bio->sector, r1_bio->sectors, + test_bit(R1BIO_BehindIO, &r1_bio->state)); + first_clone = 0; + } + + if (r1_bio->behind_master_bio) { + mbio = bio_alloc_clone(rdev->bdev, + r1_bio->behind_master_bio, + GFP_NOIO, &mddev->bio_set); + if (test_bit(CollisionCheck, &rdev->flags)) + wait_for_serialization(rdev, r1_bio); + if (test_bit(WriteMostly, &rdev->flags)) + atomic_inc(&r1_bio->behind_remaining); + } else { + mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, + &mddev->bio_set); + + if (mddev->serialize_policy) + wait_for_serialization(rdev, r1_bio); + } + + r1_bio->bios[i] = mbio; + + mbio->bi_iter.bi_sector = (r1_bio->sector + rdev->data_offset); + mbio->bi_end_io = raid1_end_write_request; + mbio->bi_opf = bio_op(bio) | (bio->bi_opf & (REQ_SYNC | REQ_FUA)); + if (test_bit(FailFast, &rdev->flags) && + !test_bit(WriteMostly, &rdev->flags) && + conf->raid_disks - mddev->degraded > 1) + mbio->bi_opf |= MD_FAILFAST; + mbio->bi_private = r1_bio; + + atomic_inc(&r1_bio->remaining); + + if (mddev->gendisk) + trace_block_bio_remap(mbio, disk_devt(mddev->gendisk), + r1_bio->sector); + /* flush_pending_writes() needs access to the rdev so...*/ + mbio->bi_bdev = (void *)rdev; + if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug, disks)) { + spin_lock_irqsave(&conf->device_lock, flags); + bio_list_add(&conf->pending_bio_list, mbio); + spin_unlock_irqrestore(&conf->device_lock, flags); + md_wakeup_thread(mddev->thread); + } + } + + r1_bio_write_done(r1_bio); + + /* In case raid1d snuck in to freeze_array */ + wake_up_barrier(conf); +} + +static bool raid1_make_request(struct mddev *mddev, struct bio *bio) +{ + sector_t sectors; + + if (unlikely(bio->bi_opf & REQ_PREFLUSH) + && md_flush_request(mddev, bio)) + return true; + + /* + * There is a limit to the maximum size, but + * the read/write handler might find a lower limit + * due to bad blocks. To avoid multiple splits, + * we pass the maximum number of sectors down + * and let the lower level perform the split. + */ + sectors = align_to_barrier_unit_end( + bio->bi_iter.bi_sector, bio_sectors(bio)); + + if (bio_data_dir(bio) == READ) + raid1_read_request(mddev, bio, sectors, NULL); + else { + if (!md_write_start(mddev,bio)) + return false; + raid1_write_request(mddev, bio, sectors); + } + return true; +} + +static void raid1_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, "]"); +} + +/** + * raid1_error() - RAID1 error handler. + * @mddev: affected md device. + * @rdev: member device to fail. + * + * The routine acknowledges &rdev failure and determines new @mddev state. + * If it failed, then: + * - &MD_BROKEN flag is set in &mddev->flags. + * - recovery is disabled. + * Otherwise, it must be degraded: + * - recovery is interrupted. + * - &mddev->degraded is bumped. + * + * @rdev is marked as &Faulty excluding case when array is failed and + * &mddev->fail_last_dev is off. + */ +static void raid1_error(struct mddev *mddev, struct md_rdev *rdev) +{ + struct r1conf *conf = mddev->private; + unsigned long flags; + + spin_lock_irqsave(&conf->device_lock, flags); + + if (test_bit(In_sync, &rdev->flags) && + (conf->raid_disks - mddev->degraded) == 1) { + set_bit(MD_BROKEN, &mddev->flags); + + if (!mddev->fail_last_dev) { + conf->recovery_disabled = mddev->recovery_disabled; + spin_unlock_irqrestore(&conf->device_lock, flags); + return; + } + } + set_bit(Blocked, &rdev->flags); + if (test_and_clear_bit(In_sync, &rdev->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); + set_mask_bits(&mddev->sb_flags, 0, + BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); + pr_crit("md/raid1:%s: Disk failure on %pg, disabling device.\n" + "md/raid1:%s: Operation continuing on %d devices.\n", + mdname(mddev), rdev->bdev, + mdname(mddev), conf->raid_disks - mddev->degraded); +} + +static void print_conf(struct r1conf *conf) +{ + int i; + + pr_debug("RAID1 conf printout:\n"); + if (!conf) { + pr_debug("(!conf)\n"); + return; + } + pr_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++) { + struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + if (rdev) + pr_debug(" disk %d, wo:%d, o:%d, dev:%pg\n", + i, !test_bit(In_sync, &rdev->flags), + !test_bit(Faulty, &rdev->flags), + rdev->bdev); + } + rcu_read_unlock(); +} + +static void close_sync(struct r1conf *conf) +{ + int idx; + + for (idx = 0; idx < BARRIER_BUCKETS_NR; idx++) { + _wait_barrier(conf, idx, false); + _allow_barrier(conf, idx); + } + + mempool_exit(&conf->r1buf_pool); +} + +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. + * device_lock used to avoid races with raid1_end_read_request + * which expects 'In_sync' flags and ->degraded to be consistent. + */ + spin_lock_irqsave(&conf->device_lock, flags); + 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 + && !test_bit(Candidate, &repl->flags) + && 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); + } + } + 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, repl_slot = -1; + struct raid1_info *p; + int first = 0; + int last = conf->raid_disks - 1; + + if (mddev->recovery_disabled == conf->recovery_disabled) + return -EBUSY; + + if (md_integrity_add_rdev(rdev, mddev)) + return -ENXIO; + + if (rdev->raid_disk >= 0) + first = last = rdev->raid_disk; + + /* + * find the disk ... but prefer rdev->saved_raid_disk + * if possible. + */ + if (rdev->saved_raid_disk >= 0 && + rdev->saved_raid_disk >= first && + rdev->saved_raid_disk < conf->raid_disks && + conf->mirrors[rdev->saved_raid_disk].rdev == NULL) + first = last = rdev->saved_raid_disk; + + 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 && repl_slot < 0) + repl_slot = mirror; + } + + if (err && repl_slot >= 0) { + /* Add this device as a replacement */ + p = conf->mirrors + repl_slot; + clear_bit(In_sync, &rdev->flags); + set_bit(Replacement, &rdev->flags); + rdev->raid_disk = repl_slot; + err = 0; + conf->fullsync = 1; + rcu_assign_pointer(p[conf->raid_disks].rdev, rdev); + } + + 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 (unlikely(number >= conf->raid_disks)) + goto abort; + + 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; + if (!test_bit(RemoveSynchronized, &rdev->flags)) { + synchronize_rcu(); + if (atomic_read(&rdev->nr_pending)) { + /* lost the race, try later */ + err = -EBUSY; + p->rdev = rdev; + goto abort; + } + } + 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); + if (atomic_read(&repl->nr_pending)) { + /* It means that some queued IO of retry_list + * hold repl. Thus, we cannot set replacement + * as NULL, avoiding rdev NULL pointer + * dereference in sync_request_write and + * handle_write_finished. + */ + err = -EBUSY; + unfreeze_array(conf); + goto abort; + } + clear_bit(Replacement, &repl->flags); + p->rdev = repl; + conf->mirrors[conf->raid_disks + number].rdev = NULL; + unfreeze_array(conf); + } + + clear_bit(WantReplacement, &rdev->flags); + err = md_integrity_register(mddev); + } +abort: + + print_conf(conf); + return err; +} + +static void end_sync_read(struct bio *bio) +{ + struct r1bio *r1_bio = get_resync_r1bio(bio); + + 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 (!bio->bi_status) + set_bit(R1BIO_Uptodate, &r1_bio->state); + + if (atomic_dec_and_test(&r1_bio->remaining)) + reschedule_retry(r1_bio); +} + +static void abort_sync_write(struct mddev *mddev, struct r1bio *r1_bio) +{ + sector_t sync_blocks = 0; + sector_t s = r1_bio->sector; + long sectors_to_go = r1_bio->sectors; + + /* make sure these bits don't get cleared. */ + do { + md_bitmap_end_sync(mddev->bitmap, s, &sync_blocks, 1); + s += sync_blocks; + sectors_to_go -= sync_blocks; + } while (sectors_to_go > 0); +} + +static void put_sync_write_buf(struct r1bio *r1_bio, int uptodate) +{ + if (atomic_dec_and_test(&r1_bio->remaining)) { + struct mddev *mddev = r1_bio->mddev; + 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 void end_sync_write(struct bio *bio) +{ + int uptodate = !bio->bi_status; + struct r1bio *r1_bio = get_resync_r1bio(bio); + struct mddev *mddev = r1_bio->mddev; + struct r1conf *conf = mddev->private; + sector_t first_bad; + int bad_sectors; + struct md_rdev *rdev = conf->mirrors[find_bio_disk(r1_bio, bio)].rdev; + + if (!uptodate) { + abort_sync_write(mddev, r1_bio); + set_bit(WriteErrorSeen, &rdev->flags); + if (!test_and_set_bit(WantReplacement, &rdev->flags)) + set_bit(MD_RECOVERY_NEEDED, & + mddev->recovery); + set_bit(R1BIO_WriteError, &r1_bio->state); + } else if (is_badblock(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); + + put_sync_write_buf(r1_bio, uptodate); +} + +static int r1_sync_page_io(struct md_rdev *rdev, sector_t sector, + int sectors, struct page *page, blk_opf_t rw) +{ + if (sync_page_io(rdev, sector, sectors << 9, page, rw, false)) + /* success */ + return 1; + if (rw == REQ_OP_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]; + struct page **pages = get_resync_pages(bio)->pages; + sector_t sect = r1_bio->sector; + int sectors = r1_bio->sectors; + int idx = 0; + struct md_rdev *rdev; + + rdev = conf->mirrors[r1_bio->read_disk].rdev; + if (test_bit(FailFast, &rdev->flags)) { + /* Don't try recovering from here - just fail it + * ... unless it is the last working device of course */ + md_error(mddev, rdev); + if (test_bit(Faulty, &rdev->flags)) + /* Don't try to read from here, but make sure + * put_buf does it's thing + */ + bio->bi_end_io = end_sync_write; + } + + while(sectors) { + int s = sectors; + int d = r1_bio->read_disk; + int success = 0; + 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, + pages[idx], + REQ_OP_READ, false)) { + success = 1; + break; + } + } + d++; + if (d == conf->raid_disks * 2) + d = 0; + } while (!success && d != r1_bio->read_disk); + + if (!success) { + 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. + */ + pr_crit_ratelimited("md/raid1:%s: %pg: unrecoverable I/O read error for block %llu\n", + mdname(mddev), bio->bi_bdev, + (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, + pages[idx], + REQ_OP_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, + pages[idx], + REQ_OP_READ) != 0) + atomic_add(s, &rdev->corrected_errors); + } + sectors -= s; + sect += s; + idx ++; + } + set_bit(R1BIO_Uptodate, &r1_bio->state); + bio->bi_status = 0; + return 1; +} + +static void 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++) { + blk_status_t status; + struct bio *b = r1_bio->bios[i]; + struct resync_pages *rp = get_resync_pages(b); + if (b->bi_end_io != end_sync_read) + continue; + /* fixup the bio for reuse, but preserve errno */ + status = b->bi_status; + bio_reset(b, conf->mirrors[i].rdev->bdev, REQ_OP_READ); + b->bi_status = status; + b->bi_iter.bi_sector = r1_bio->sector + + conf->mirrors[i].rdev->data_offset; + b->bi_end_io = end_sync_read; + rp->raid_bio = r1_bio; + b->bi_private = rp; + + /* initialize bvec table again */ + md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9); + } + for (primary = 0; primary < conf->raid_disks * 2; primary++) + if (r1_bio->bios[primary]->bi_end_io == end_sync_read && + !r1_bio->bios[primary]->bi_status) { + 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 = 0; + struct bio *pbio = r1_bio->bios[primary]; + struct bio *sbio = r1_bio->bios[i]; + blk_status_t status = sbio->bi_status; + struct page **ppages = get_resync_pages(pbio)->pages; + struct page **spages = get_resync_pages(sbio)->pages; + struct bio_vec *bi; + int page_len[RESYNC_PAGES] = { 0 }; + struct bvec_iter_all iter_all; + + if (sbio->bi_end_io != end_sync_read) + continue; + /* Now we can 'fixup' the error value */ + sbio->bi_status = 0; + + bio_for_each_segment_all(bi, sbio, iter_all) + page_len[j++] = bi->bv_len; + + if (!status) { + for (j = vcnt; j-- ; ) { + if (memcmp(page_address(ppages[j]), + page_address(spages[j]), + page_len[j])) + 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) + && !status)) { + /* 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); + } +} + +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 *wbio; + + 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)) + process_checks(r1_bio); + + /* + * 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; + if (test_bit(Faulty, &conf->mirrors[i].rdev->flags)) { + abort_sync_write(mddev, r1_bio); + continue; + } + + wbio->bi_opf = REQ_OP_WRITE; + if (test_bit(FailFast, &conf->mirrors[i].rdev->flags)) + wbio->bi_opf |= MD_FAILFAST; + + wbio->bi_end_io = end_sync_write; + atomic_inc(&r1_bio->remaining); + md_sync_acct(conf->mirrors[i].rdev->bdev, bio_sectors(wbio)); + + submit_bio_noacct(wbio); + } + + put_sync_write_buf(r1_bio, 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 { + sector_t first_bad; + int bad_sectors; + + rcu_read_lock(); + rdev = rcu_dereference(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) { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + if (sync_page_io(rdev, sect, s<<9, + conf->tmppage, REQ_OP_READ, false)) + success = 1; + rdev_dec_pending(rdev, mddev); + if (success) + break; + } else + rcu_read_unlock(); + d++; + if (d == conf->raid_disks * 2) + d = 0; + } while (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--; + rcu_read_lock(); + rdev = rcu_dereference(conf->mirrors[d].rdev); + if (rdev && + !test_bit(Faulty, &rdev->flags)) { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + r1_sync_page_io(rdev, sect, s, + conf->tmppage, REQ_OP_WRITE); + rdev_dec_pending(rdev, mddev); + } else + rcu_read_unlock(); + } + d = start; + while (d != read_disk) { + if (d==0) + d = conf->raid_disks * 2; + d--; + rcu_read_lock(); + rdev = rcu_dereference(conf->mirrors[d].rdev); + if (rdev && + !test_bit(Faulty, &rdev->flags)) { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + if (r1_sync_page_io(rdev, sect, s, + conf->tmppage, REQ_OP_READ)) { + atomic_add(s, &rdev->corrected_errors); + pr_info("md/raid1:%s: read error corrected (%d sectors at %llu on %pg)\n", + mdname(mddev), s, + (unsigned long long)(sect + + rdev->data_offset), + rdev->bdev); + } + rdev_dec_pending(rdev, mddev); + } else + rcu_read_unlock(); + } + 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 = roundup(1 << rdev->badblocks.shift, + bdev_logical_block_size(rdev->bdev) >> 9); + 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)) { + wbio = bio_alloc_clone(rdev->bdev, + r1_bio->behind_master_bio, + GFP_NOIO, &mddev->bio_set); + } else { + wbio = bio_alloc_clone(rdev->bdev, r1_bio->master_bio, + GFP_NOIO, &mddev->bio_set); + } + + wbio->bi_opf = REQ_OP_WRITE; + wbio->bi_iter.bi_sector = r1_bio->sector; + wbio->bi_iter.bi_size = r1_bio->sectors << 9; + + bio_trim(wbio, sector - r1_bio->sector, sectors); + wbio->bi_iter.bi_sector += rdev->data_offset; + + if (submit_bio_wait(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 (!bio->bi_status && + test_bit(R1BIO_MadeGood, &r1_bio->state)) { + rdev_clear_badblocks(rdev, r1_bio->sector, s, 0); + } + if (bio->bi_status && + 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, idx; + bool fail = false; + + 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. + */ + fail = true; + 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 (fail) { + spin_lock_irq(&conf->device_lock); + list_add(&r1_bio->retry_list, &conf->bio_end_io_list); + idx = sector_to_idx(r1_bio->sector); + atomic_inc(&conf->nr_queued[idx]); + spin_unlock_irq(&conf->device_lock); + /* + * In case freeze_array() is waiting for condition + * get_unqueued_pending() == extra to be true. + */ + wake_up(&conf->wait_barrier); + md_wakeup_thread(conf->mddev->thread); + } else { + 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) +{ + struct mddev *mddev = conf->mddev; + struct bio *bio; + struct md_rdev *rdev; + sector_t sector; + + 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 + */ + + bio = r1_bio->bios[r1_bio->read_disk]; + bio_put(bio); + r1_bio->bios[r1_bio->read_disk] = NULL; + + rdev = conf->mirrors[r1_bio->read_disk].rdev; + if (mddev->ro == 0 + && !test_bit(FailFast, &rdev->flags)) { + freeze_array(conf, 1); + fix_read_error(conf, r1_bio->read_disk, + r1_bio->sector, r1_bio->sectors); + unfreeze_array(conf); + } else if (mddev->ro == 0 && test_bit(FailFast, &rdev->flags)) { + md_error(mddev, rdev); + } else { + r1_bio->bios[r1_bio->read_disk] = IO_BLOCKED; + } + + rdev_dec_pending(rdev, conf->mddev); + sector = r1_bio->sector; + bio = r1_bio->master_bio; + + /* Reuse the old r1_bio so that the IO_BLOCKED settings are preserved */ + r1_bio->state = 0; + raid1_read_request(mddev, bio, r1_bio->sectors, r1_bio); + allow_barrier(conf, sector); +} + +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; + int idx; + + md_check_recovery(mddev); + + if (!list_empty_careful(&conf->bio_end_io_list) && + !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) { + LIST_HEAD(tmp); + spin_lock_irqsave(&conf->device_lock, flags); + if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) + list_splice_init(&conf->bio_end_io_list, &tmp); + spin_unlock_irqrestore(&conf->device_lock, flags); + while (!list_empty(&tmp)) { + r1_bio = list_first_entry(&tmp, struct r1bio, + retry_list); + list_del(&r1_bio->retry_list); + idx = sector_to_idx(r1_bio->sector); + atomic_dec(&conf->nr_queued[idx]); + if (mddev->degraded) + set_bit(R1BIO_Degraded, &r1_bio->state); + if (test_bit(R1BIO_WriteError, &r1_bio->state)) + close_write(r1_bio); + raid_end_bio_io(r1_bio); + } + } + + 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); + idx = sector_to_idx(r1_bio->sector); + atomic_dec(&conf->nr_queued[idx]); + 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 + WARN_ON_ONCE(1); + + cond_resched(); + if (mddev->sb_flags & ~(1<<MD_SB_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(mempool_initialized(&conf->r1buf_pool)); + + return mempool_init(&conf->r1buf_pool, buffs, r1buf_pool_alloc, + r1buf_pool_free, conf->poolinfo); +} + +static struct r1bio *raid1_alloc_init_r1buf(struct r1conf *conf) +{ + struct r1bio *r1bio = mempool_alloc(&conf->r1buf_pool, GFP_NOIO); + struct resync_pages *rps; + struct bio *bio; + int i; + + for (i = conf->poolinfo->raid_disks; i--; ) { + bio = r1bio->bios[i]; + rps = bio->bi_private; + bio_reset(bio, NULL, 0); + bio->bi_private = rps; + } + r1bio->master_bio = NULL; + return r1bio; +} + +/* + * 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 raid1_sync_request(struct mddev *mddev, sector_t sector_nr, + int *skipped) +{ + 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 */ + int idx = sector_to_idx(sector_nr); + int page_idx = 0; + + if (!mempool_initialized(&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 */ + md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync, + &sync_blocks, 1); + else /* completed sync */ + conf->fullsync = 0; + + md_bitmap_close_sync(mddev->bitmap); + close_sync(conf); + + if (mddev_is_clustered(mddev)) { + conf->cluster_sync_low = 0; + conf->cluster_sync_high = 0; + } + 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 (!md_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, then let it + * though before starting on this new sync request. + */ + if (atomic_read(&conf->nr_waiting[idx])) + schedule_timeout_uninterruptible(1); + + /* we are incrementing sector_nr below. To be safe, we check against + * sector_nr + two times RESYNC_SECTORS + */ + + md_bitmap_cond_end_sync(mddev->bitmap, sector_nr, + mddev_is_clustered(mddev) && (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high)); + + + if (raise_barrier(conf, sector_nr)) + return 0; + + r1_bio = raid1_alloc_init_r1buf(conf); + + 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); + /* make sure good_sectors won't go across barrier unit boundary */ + good_sectors = align_to_barrier_unit_end(sector_nr, good_sectors); + + for (i = 0; i < conf->raid_disks * 2; i++) { + struct md_rdev *rdev; + bio = r1_bio->bios[i]; + + 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_opf = REQ_OP_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_opf = REQ_OP_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_opf = REQ_OP_WRITE; + bio->bi_end_io = end_sync_write; + write_targets++; + } + } + if (rdev && bio->bi_end_io) { + atomic_inc(&rdev->nr_pending); + bio->bi_iter.bi_sector = sector_nr + rdev->data_offset; + bio_set_dev(bio, rdev->bdev); + if (test_bit(FailFast, &rdev->flags)) + bio->bi_opf |= MD_FAILFAST; + } + } + 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_SB_CHANGE_DEVS, &mddev->sb_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 (!md_bitmap_start_sync(mddev->bitmap, sector_nr, + &sync_blocks, still_degraded) && + !conf->fullsync && + !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) + break; + if ((len >> 9) > sync_blocks) + len = sync_blocks<<9; + } + + for (i = 0 ; i < conf->raid_disks * 2; i++) { + struct resync_pages *rp; + + bio = r1_bio->bios[i]; + rp = get_resync_pages(bio); + if (bio->bi_end_io) { + page = resync_fetch_page(rp, page_idx); + + /* + * won't fail because the vec table is big + * enough to hold all these pages + */ + __bio_add_page(bio, page, len, 0); + } + } + nr_sectors += len>>9; + sector_nr += len>>9; + sync_blocks -= (len>>9); + } while (++page_idx < RESYNC_PAGES); + + r1_bio->sectors = nr_sectors; + + if (mddev_is_clustered(mddev) && + conf->cluster_sync_high < sector_nr + nr_sectors) { + conf->cluster_sync_low = mddev->curr_resync_completed; + conf->cluster_sync_high = conf->cluster_sync_low + CLUSTER_RESYNC_WINDOW_SECTORS; + /* Send resync message */ + md_cluster_ops->resync_info_update(mddev, + conf->cluster_sync_low, + conf->cluster_sync_high); + } + + /* 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(bio, nr_sectors); + if (read_targets == 1) + bio->bi_opf &= ~MD_FAILFAST; + submit_bio_noacct(bio); + } + } + } else { + atomic_set(&r1_bio->remaining, 1); + bio = r1_bio->bios[r1_bio->read_disk]; + md_sync_acct_bio(bio, nr_sectors); + if (read_targets == 1) + bio->bi_opf &= ~MD_FAILFAST; + submit_bio_noacct(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->nr_pending = kcalloc(BARRIER_BUCKETS_NR, + sizeof(atomic_t), GFP_KERNEL); + if (!conf->nr_pending) + goto abort; + + conf->nr_waiting = kcalloc(BARRIER_BUCKETS_NR, + sizeof(atomic_t), GFP_KERNEL); + if (!conf->nr_waiting) + goto abort; + + conf->nr_queued = kcalloc(BARRIER_BUCKETS_NR, + sizeof(atomic_t), GFP_KERNEL); + if (!conf->nr_queued) + goto abort; + + conf->barrier = kcalloc(BARRIER_BUCKETS_NR, + sizeof(atomic_t), GFP_KERNEL); + if (!conf->barrier) + goto abort; + + conf->mirrors = kzalloc(array3_size(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; + err = mempool_init(&conf->r1bio_pool, NR_RAID_BIOS, r1bio_pool_alloc, + rbio_pool_free, conf->poolinfo); + if (err) + goto abort; + + err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0); + if (err) + goto abort; + + conf->poolinfo->mddev = mddev; + + err = -EINVAL; + spin_lock_init(&conf->device_lock); + rdev_for_each(rdev, mddev) { + 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; + disk->head_position = 0; + disk->seq_start = MaxSector; + } + conf->raid_disks = mddev->raid_disks; + conf->mddev = mddev; + INIT_LIST_HEAD(&conf->retry_list); + INIT_LIST_HEAD(&conf->bio_end_io_list); + + spin_lock_init(&conf->resync_lock); + init_waitqueue_head(&conf->wait_barrier); + + bio_list_init(&conf->pending_bio_list); + conf->recovery_disabled = mddev->recovery_disabled - 1; + + 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; + rcu_assign_pointer(conf->thread, + md_register_thread(raid1d, mddev, "raid1")); + if (!conf->thread) + goto abort; + + return conf; + + abort: + if (conf) { + mempool_exit(&conf->r1bio_pool); + kfree(conf->mirrors); + safe_put_page(conf->tmppage); + kfree(conf->poolinfo); + kfree(conf->nr_pending); + kfree(conf->nr_waiting); + kfree(conf->nr_queued); + kfree(conf->barrier); + bioset_exit(&conf->bio_split); + kfree(conf); + } + return ERR_PTR(err); +} + +static void raid1_free(struct mddev *mddev, void *priv); +static int raid1_run(struct mddev *mddev) +{ + struct r1conf *conf; + int i; + struct md_rdev *rdev; + int ret; + + if (mddev->level != 1) { + pr_warn("md/raid1:%s: raid level not set to mirroring (%d)\n", + mdname(mddev), mddev->level); + return -EIO; + } + if (mddev->reshape_position != MaxSector) { + pr_warn("md/raid1:%s: reshape_position set but not supported\n", + mdname(mddev)); + return -EIO; + } + if (mddev_init_writes_pending(mddev) < 0) + return -ENOMEM; + /* + * copy the already verified devices into our private RAID1 + * bookkeeping area. [whatever we allocate in run(), + * should be freed in raid1_free()] + */ + 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_zeroes_sectors(mddev->queue, 0); + + 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++; + /* + * RAID1 needs at least one disk in active + */ + if (conf->raid_disks - mddev->degraded < 1) { + md_unregister_thread(mddev, &conf->thread); + ret = -EINVAL; + goto abort; + } + + if (conf->raid_disks - mddev->degraded == 1) + mddev->recovery_cp = MaxSector; + + if (mddev->recovery_cp != MaxSector) + pr_info("md/raid1:%s: not clean -- starting background reconstruction\n", + mdname(mddev)); + pr_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 + */ + rcu_assign_pointer(mddev->thread, conf->thread); + rcu_assign_pointer(conf->thread, NULL); + mddev->private = conf; + set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags); + + md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); + + ret = md_integrity_register(mddev); + if (ret) { + md_unregister_thread(mddev, &mddev->thread); + goto abort; + } + return 0; + +abort: + raid1_free(mddev, conf); + return ret; +} + +static void raid1_free(struct mddev *mddev, void *priv) +{ + struct r1conf *conf = priv; + + mempool_exit(&conf->r1bio_pool); + kfree(conf->mirrors); + safe_put_page(conf->tmppage); + kfree(conf->poolinfo); + kfree(conf->nr_pending); + kfree(conf->nr_waiting); + kfree(conf->nr_queued); + kfree(conf->barrier); + bioset_exit(&conf->bio_split); + kfree(conf); +} + +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 = md_bitmap_resize(mddev->bitmap, newsize, 0, 0); + if (ret) + return ret; + } + md_set_array_sectors(mddev, newsize); + 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; + int ret; + + memset(&newpool, 0, sizeof(newpool)); + memset(&oldpool, 0, sizeof(oldpool)); + + /* 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; + } + + if (!mddev_is_clustered(mddev)) + md_allow_write(mddev); + + 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; + + ret = mempool_init(&newpool, NR_RAID_BIOS, r1bio_pool_alloc, + rbio_pool_free, newpoolinfo); + if (ret) { + kfree(newpoolinfo); + return ret; + } + newmirrors = kzalloc(array3_size(sizeof(struct raid1_info), + raid_disks, 2), + GFP_KERNEL); + if (!newmirrors) { + kfree(newpoolinfo); + mempool_exit(&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)) + pr_warn("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_RECOVER, &mddev->recovery); + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + md_wakeup_thread(mddev->thread); + + mempool_exit(&oldpool); + return 0; +} + +static void raid1_quiesce(struct mddev *mddev, int quiesce) +{ + struct r1conf *conf = mddev->private; + + if (quiesce) + freeze_array(conf, 0); + else + unfreeze_array(conf); +} + +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; + mddev_clear_unsupported_flags(mddev, + UNSUPPORTED_MDDEV_FLAGS); + } + return conf; + } + return ERR_PTR(-EINVAL); +} + +static struct md_personality raid1_personality = +{ + .name = "raid1", + .level = 1, + .owner = THIS_MODULE, + .make_request = raid1_make_request, + .run = raid1_run, + .free = raid1_free, + .status = raid1_status, + .error_handler = raid1_error, + .hot_add_disk = raid1_add_disk, + .hot_remove_disk= raid1_remove_disk, + .spare_active = raid1_spare_active, + .sync_request = raid1_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"); |