diff options
Diffstat (limited to 'drivers/md/raid10.c')
| -rw-r--r-- | drivers/md/raid10.c | 5315 |
1 files changed, 5315 insertions, 0 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c new file mode 100644 index 000000000..023413120 --- /dev/null +++ b/drivers/md/raid10.c @@ -0,0 +1,5315 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * raid10.c : Multiple Devices driver for Linux + * + * Copyright (C) 2000-2004 Neil Brown + * + * RAID-10 support for md. + * + * Base on code in raid1.c. See raid1.c for further copyright information. + */ + +#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/kthread.h> +#include <linux/raid/md_p.h> +#include <trace/events/block.h> +#include "md.h" +#include "raid10.h" +#include "raid0.h" +#include "md-bitmap.h" + +/* + * RAID10 provides a combination of RAID0 and RAID1 functionality. + * The layout of data is defined by + * chunk_size + * raid_disks + * near_copies (stored in low byte of layout) + * far_copies (stored in second byte of layout) + * far_offset (stored in bit 16 of layout ) + * use_far_sets (stored in bit 17 of layout ) + * use_far_sets_bugfixed (stored in bit 18 of layout ) + * + * The data to be stored is divided into chunks using chunksize. Each device + * is divided into far_copies sections. In each section, chunks are laid out + * in a style similar to raid0, but near_copies copies of each chunk is stored + * (each on a different drive). The starting device for each section is offset + * near_copies from the starting device of the previous section. Thus there + * are (near_copies * far_copies) of each chunk, and each is on a different + * drive. near_copies and far_copies must be at least one, and their product + * is at most raid_disks. + * + * If far_offset is true, then the far_copies are handled a bit differently. + * The copies are still in different stripes, but instead of being very far + * apart on disk, there are adjacent stripes. + * + * The far and offset algorithms are handled slightly differently if + * 'use_far_sets' is true. In this case, the array's devices are grouped into + * sets that are (near_copies * far_copies) in size. The far copied stripes + * are still shifted by 'near_copies' devices, but this shifting stays confined + * to the set rather than the entire array. This is done to improve the number + * of device combinations that can fail without causing the array to fail. + * Example 'far' algorithm w/o 'use_far_sets' (each letter represents a chunk + * on a device): + * A B C D A B C D E + * ... ... + * D A B C E A B C D + * Example 'far' algorithm w/ 'use_far_sets' enabled (sets illustrated w/ []'s): + * [A B] [C D] [A B] [C D E] + * |...| |...| |...| | ... | + * [B A] [D C] [B A] [E C D] + */ + +static void allow_barrier(struct r10conf *conf); +static void lower_barrier(struct r10conf *conf); +static int _enough(struct r10conf *conf, int previous, int ignore); +static int enough(struct r10conf *conf, int ignore); +static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, + int *skipped); +static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio); +static void end_reshape_write(struct bio *bio); +static void end_reshape(struct r10conf *conf); + +#define raid10_log(md, fmt, args...) \ + do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid10 " fmt, ##args); } while (0) + +#include "raid1-10.c" + +#define NULL_CMD +#define cmd_before(conf, cmd) \ + do { \ + write_sequnlock_irq(&(conf)->resync_lock); \ + cmd; \ + } while (0) +#define cmd_after(conf) write_seqlock_irq(&(conf)->resync_lock) + +#define wait_event_barrier_cmd(conf, cond, cmd) \ + wait_event_cmd((conf)->wait_barrier, cond, cmd_before(conf, cmd), \ + cmd_after(conf)) + +#define wait_event_barrier(conf, cond) \ + wait_event_barrier_cmd(conf, cond, NULL_CMD) + +/* + * for resync bio, r10bio pointer can be retrieved from the per-bio + * 'struct resync_pages'. + */ +static inline struct r10bio *get_resync_r10bio(struct bio *bio) +{ + return get_resync_pages(bio)->raid_bio; +} + +static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) +{ + struct r10conf *conf = data; + int size = offsetof(struct r10bio, devs[conf->geo.raid_disks]); + + /* allocate a r10bio with room for raid_disks entries in the + * bios array */ + return kzalloc(size, gfp_flags); +} + +#define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) +/* amount of memory to reserve for resync requests */ +#define RESYNC_WINDOW (1024*1024) +/* maximum number of concurrent requests, memory permitting */ +#define RESYNC_DEPTH (32*1024*1024/RESYNC_BLOCK_SIZE) +#define CLUSTER_RESYNC_WINDOW (32 * RESYNC_WINDOW) +#define CLUSTER_RESYNC_WINDOW_SECTORS (CLUSTER_RESYNC_WINDOW >> 9) + +/* + * When performing a resync, we need to read and compare, so + * we need as many pages are there are copies. + * When performing a recovery, we need 2 bios, one for read, + * one for write (we recover only one drive per r10buf) + * + */ +static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) +{ + struct r10conf *conf = data; + struct r10bio *r10_bio; + struct bio *bio; + int j; + int nalloc, nalloc_rp; + struct resync_pages *rps; + + r10_bio = r10bio_pool_alloc(gfp_flags, conf); + if (!r10_bio) + return NULL; + + if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) || + test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery)) + nalloc = conf->copies; /* resync */ + else + nalloc = 2; /* recovery */ + + /* allocate once for all bios */ + if (!conf->have_replacement) + nalloc_rp = nalloc; + else + nalloc_rp = nalloc * 2; + rps = kmalloc_array(nalloc_rp, sizeof(struct resync_pages), gfp_flags); + if (!rps) + goto out_free_r10bio; + + /* + * Allocate bios. + */ + for (j = nalloc ; 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); + r10_bio->devs[j].bio = bio; + if (!conf->have_replacement) + continue; + bio = bio_kmalloc(RESYNC_PAGES, gfp_flags); + if (!bio) + goto out_free_bio; + bio_init(bio, NULL, bio->bi_inline_vecs, RESYNC_PAGES, 0); + r10_bio->devs[j].repl_bio = bio; + } + /* + * Allocate RESYNC_PAGES data pages and attach them + * where needed. + */ + for (j = 0; j < nalloc; j++) { + struct bio *rbio = r10_bio->devs[j].repl_bio; + struct resync_pages *rp, *rp_repl; + + rp = &rps[j]; + if (rbio) + rp_repl = &rps[nalloc + j]; + + bio = r10_bio->devs[j].bio; + + if (!j || test_bit(MD_RECOVERY_SYNC, + &conf->mddev->recovery)) { + 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 = r10_bio; + bio->bi_private = rp; + if (rbio) { + memcpy(rp_repl, rp, sizeof(*rp)); + rbio->bi_private = rp_repl; + } + } + + return r10_bio; + +out_free_pages: + while (--j >= 0) + resync_free_pages(&rps[j]); + + j = 0; +out_free_bio: + for ( ; j < nalloc; j++) { + if (r10_bio->devs[j].bio) + bio_uninit(r10_bio->devs[j].bio); + kfree(r10_bio->devs[j].bio); + if (r10_bio->devs[j].repl_bio) + bio_uninit(r10_bio->devs[j].repl_bio); + kfree(r10_bio->devs[j].repl_bio); + } + kfree(rps); +out_free_r10bio: + rbio_pool_free(r10_bio, conf); + return NULL; +} + +static void r10buf_pool_free(void *__r10_bio, void *data) +{ + struct r10conf *conf = data; + struct r10bio *r10bio = __r10_bio; + int j; + struct resync_pages *rp = NULL; + + for (j = conf->copies; j--; ) { + struct bio *bio = r10bio->devs[j].bio; + + if (bio) { + rp = get_resync_pages(bio); + resync_free_pages(rp); + bio_uninit(bio); + kfree(bio); + } + + bio = r10bio->devs[j].repl_bio; + if (bio) { + bio_uninit(bio); + kfree(bio); + } + } + + /* resync pages array stored in the 1st bio's .bi_private */ + kfree(rp); + + rbio_pool_free(r10bio, conf); +} + +static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio) +{ + int i; + + for (i = 0; i < conf->geo.raid_disks; i++) { + struct bio **bio = & r10_bio->devs[i].bio; + if (!BIO_SPECIAL(*bio)) + bio_put(*bio); + *bio = NULL; + bio = &r10_bio->devs[i].repl_bio; + if (r10_bio->read_slot < 0 && !BIO_SPECIAL(*bio)) + bio_put(*bio); + *bio = NULL; + } +} + +static void free_r10bio(struct r10bio *r10_bio) +{ + struct r10conf *conf = r10_bio->mddev->private; + + put_all_bios(conf, r10_bio); + mempool_free(r10_bio, &conf->r10bio_pool); +} + +static void put_buf(struct r10bio *r10_bio) +{ + struct r10conf *conf = r10_bio->mddev->private; + + mempool_free(r10_bio, &conf->r10buf_pool); + + lower_barrier(conf); +} + +static void wake_up_barrier(struct r10conf *conf) +{ + if (wq_has_sleeper(&conf->wait_barrier)) + wake_up(&conf->wait_barrier); +} + +static void reschedule_retry(struct r10bio *r10_bio) +{ + unsigned long flags; + struct mddev *mddev = r10_bio->mddev; + struct r10conf *conf = mddev->private; + + spin_lock_irqsave(&conf->device_lock, flags); + list_add(&r10_bio->retry_list, &conf->retry_list); + conf->nr_queued ++; + spin_unlock_irqrestore(&conf->device_lock, flags); + + /* wake up frozen array... */ + 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 raid_end_bio_io(struct r10bio *r10_bio) +{ + struct bio *bio = r10_bio->master_bio; + struct r10conf *conf = r10_bio->mddev->private; + + if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) + bio->bi_status = BLK_STS_IOERR; + + bio_endio(bio); + /* + * Wake up any possible resync thread that waits for the device + * to go idle. + */ + allow_barrier(conf); + + free_r10bio(r10_bio); +} + +/* + * Update disk head position estimator based on IRQ completion info. + */ +static inline void update_head_pos(int slot, struct r10bio *r10_bio) +{ + struct r10conf *conf = r10_bio->mddev->private; + + conf->mirrors[r10_bio->devs[slot].devnum].head_position = + r10_bio->devs[slot].addr + (r10_bio->sectors); +} + +/* + * Find the disk number which triggered given bio + */ +static int find_bio_disk(struct r10conf *conf, struct r10bio *r10_bio, + struct bio *bio, int *slotp, int *replp) +{ + int slot; + int repl = 0; + + for (slot = 0; slot < conf->geo.raid_disks; slot++) { + if (r10_bio->devs[slot].bio == bio) + break; + if (r10_bio->devs[slot].repl_bio == bio) { + repl = 1; + break; + } + } + + update_head_pos(slot, r10_bio); + + if (slotp) + *slotp = slot; + if (replp) + *replp = repl; + return r10_bio->devs[slot].devnum; +} + +static void raid10_end_read_request(struct bio *bio) +{ + int uptodate = !bio->bi_status; + struct r10bio *r10_bio = bio->bi_private; + int slot; + struct md_rdev *rdev; + struct r10conf *conf = r10_bio->mddev->private; + + slot = r10_bio->read_slot; + rdev = r10_bio->devs[slot].rdev; + /* + * this branch is our 'one mirror IO has finished' event handler: + */ + update_head_pos(slot, r10_bio); + + if (uptodate) { + /* + * Set R10BIO_Uptodate in our master bio, so that + * we will return a good error code to the higher + * levels even if IO on some other mirrored buffer fails. + * + * The 'master' represents the composite IO operation to + * user-side. So if something waits for IO, then it will + * wait for the 'master' bio. + */ + set_bit(R10BIO_Uptodate, &r10_bio->state); + } else { + /* If all other devices that store this block 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" + */ + if (!_enough(conf, test_bit(R10BIO_Previous, &r10_bio->state), + rdev->raid_disk)) + uptodate = 1; + } + if (uptodate) { + raid_end_bio_io(r10_bio); + rdev_dec_pending(rdev, conf->mddev); + } else { + /* + * oops, read error - keep the refcount on the rdev + */ + pr_err_ratelimited("md/raid10:%s: %pg: rescheduling sector %llu\n", + mdname(conf->mddev), + rdev->bdev, + (unsigned long long)r10_bio->sector); + set_bit(R10BIO_ReadError, &r10_bio->state); + reschedule_retry(r10_bio); + } +} + +static void close_write(struct r10bio *r10_bio) +{ + /* clear the bitmap if all writes complete successfully */ + md_bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector, + r10_bio->sectors, + !test_bit(R10BIO_Degraded, &r10_bio->state), + 0); + md_write_end(r10_bio->mddev); +} + +static void one_write_done(struct r10bio *r10_bio) +{ + if (atomic_dec_and_test(&r10_bio->remaining)) { + if (test_bit(R10BIO_WriteError, &r10_bio->state)) + reschedule_retry(r10_bio); + else { + close_write(r10_bio); + if (test_bit(R10BIO_MadeGood, &r10_bio->state)) + reschedule_retry(r10_bio); + else + raid_end_bio_io(r10_bio); + } + } +} + +static void raid10_end_write_request(struct bio *bio) +{ + struct r10bio *r10_bio = bio->bi_private; + int dev; + int dec_rdev = 1; + struct r10conf *conf = r10_bio->mddev->private; + int slot, repl; + struct md_rdev *rdev = NULL; + struct bio *to_put = NULL; + bool discard_error; + + discard_error = bio->bi_status && bio_op(bio) == REQ_OP_DISCARD; + + dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl); + + if (repl) + rdev = conf->mirrors[dev].replacement; + if (!rdev) { + smp_rmb(); + repl = 0; + rdev = conf->mirrors[dev].rdev; + } + /* + * this branch is our 'one mirror IO has finished' event handler: + */ + if (bio->bi_status && !discard_error) { + if (repl) + /* Never record new bad blocks to replacement, + * just fail it. + */ + md_error(rdev->mddev, rdev); + else { + set_bit(WriteErrorSeen, &rdev->flags); + if (!test_and_set_bit(WantReplacement, &rdev->flags)) + set_bit(MD_RECOVERY_NEEDED, + &rdev->mddev->recovery); + + dec_rdev = 0; + if (test_bit(FailFast, &rdev->flags) && + (bio->bi_opf & MD_FAILFAST)) { + md_error(rdev->mddev, rdev); + } + + /* + * When the device is faulty, it is not necessary to + * handle write error. + */ + if (!test_bit(Faulty, &rdev->flags)) + set_bit(R10BIO_WriteError, &r10_bio->state); + else { + /* Fail the request */ + set_bit(R10BIO_Degraded, &r10_bio->state); + r10_bio->devs[slot].bio = NULL; + to_put = bio; + dec_rdev = 1; + } + } + } else { + /* + * Set R10BIO_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; + + /* + * Do not set R10BIO_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(R10BIO_Uptodate, &r10_bio->state); + + /* Maybe we can clear some bad blocks. */ + if (is_badblock(rdev, + r10_bio->devs[slot].addr, + r10_bio->sectors, + &first_bad, &bad_sectors) && !discard_error) { + bio_put(bio); + if (repl) + r10_bio->devs[slot].repl_bio = IO_MADE_GOOD; + else + r10_bio->devs[slot].bio = IO_MADE_GOOD; + dec_rdev = 0; + set_bit(R10BIO_MadeGood, &r10_bio->state); + } + } + + /* + * + * Let's see if all mirrored write operations have finished + * already. + */ + one_write_done(r10_bio); + if (dec_rdev) + rdev_dec_pending(rdev, conf->mddev); + if (to_put) + bio_put(to_put); +} + +/* + * RAID10 layout manager + * As well as the chunksize and raid_disks count, there are two + * parameters: near_copies and far_copies. + * near_copies * far_copies must be <= raid_disks. + * Normally one of these will be 1. + * If both are 1, we get raid0. + * If near_copies == raid_disks, we get raid1. + * + * Chunks are laid out in raid0 style with near_copies copies of the + * first chunk, followed by near_copies copies of the next chunk and + * so on. + * If far_copies > 1, then after 1/far_copies of the array has been assigned + * as described above, we start again with a device offset of near_copies. + * So we effectively have another copy of the whole array further down all + * the drives, but with blocks on different drives. + * With this layout, and block is never stored twice on the one device. + * + * raid10_find_phys finds the sector offset of a given virtual sector + * on each device that it is on. + * + * raid10_find_virt does the reverse mapping, from a device and a + * sector offset to a virtual address + */ + +static void __raid10_find_phys(struct geom *geo, struct r10bio *r10bio) +{ + int n,f; + sector_t sector; + sector_t chunk; + sector_t stripe; + int dev; + int slot = 0; + int last_far_set_start, last_far_set_size; + + last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1; + last_far_set_start *= geo->far_set_size; + + last_far_set_size = geo->far_set_size; + last_far_set_size += (geo->raid_disks % geo->far_set_size); + + /* now calculate first sector/dev */ + chunk = r10bio->sector >> geo->chunk_shift; + sector = r10bio->sector & geo->chunk_mask; + + chunk *= geo->near_copies; + stripe = chunk; + dev = sector_div(stripe, geo->raid_disks); + if (geo->far_offset) + stripe *= geo->far_copies; + + sector += stripe << geo->chunk_shift; + + /* and calculate all the others */ + for (n = 0; n < geo->near_copies; n++) { + int d = dev; + int set; + sector_t s = sector; + r10bio->devs[slot].devnum = d; + r10bio->devs[slot].addr = s; + slot++; + + for (f = 1; f < geo->far_copies; f++) { + set = d / geo->far_set_size; + d += geo->near_copies; + + if ((geo->raid_disks % geo->far_set_size) && + (d > last_far_set_start)) { + d -= last_far_set_start; + d %= last_far_set_size; + d += last_far_set_start; + } else { + d %= geo->far_set_size; + d += geo->far_set_size * set; + } + s += geo->stride; + r10bio->devs[slot].devnum = d; + r10bio->devs[slot].addr = s; + slot++; + } + dev++; + if (dev >= geo->raid_disks) { + dev = 0; + sector += (geo->chunk_mask + 1); + } + } +} + +static void raid10_find_phys(struct r10conf *conf, struct r10bio *r10bio) +{ + struct geom *geo = &conf->geo; + + if (conf->reshape_progress != MaxSector && + ((r10bio->sector >= conf->reshape_progress) != + conf->mddev->reshape_backwards)) { + set_bit(R10BIO_Previous, &r10bio->state); + geo = &conf->prev; + } else + clear_bit(R10BIO_Previous, &r10bio->state); + + __raid10_find_phys(geo, r10bio); +} + +static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev) +{ + sector_t offset, chunk, vchunk; + /* Never use conf->prev as this is only called during resync + * or recovery, so reshape isn't happening + */ + struct geom *geo = &conf->geo; + int far_set_start = (dev / geo->far_set_size) * geo->far_set_size; + int far_set_size = geo->far_set_size; + int last_far_set_start; + + if (geo->raid_disks % geo->far_set_size) { + last_far_set_start = (geo->raid_disks / geo->far_set_size) - 1; + last_far_set_start *= geo->far_set_size; + + if (dev >= last_far_set_start) { + far_set_size = geo->far_set_size; + far_set_size += (geo->raid_disks % geo->far_set_size); + far_set_start = last_far_set_start; + } + } + + offset = sector & geo->chunk_mask; + if (geo->far_offset) { + int fc; + chunk = sector >> geo->chunk_shift; + fc = sector_div(chunk, geo->far_copies); + dev -= fc * geo->near_copies; + if (dev < far_set_start) + dev += far_set_size; + } else { + while (sector >= geo->stride) { + sector -= geo->stride; + if (dev < (geo->near_copies + far_set_start)) + dev += far_set_size - geo->near_copies; + else + dev -= geo->near_copies; + } + chunk = sector >> geo->chunk_shift; + } + vchunk = chunk * geo->raid_disks + dev; + sector_div(vchunk, geo->near_copies); + return (vchunk << geo->chunk_shift) + offset; +} + +/* + * 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. + */ + +/* + * FIXME: possibly should rethink readbalancing and do it differently + * depending on near_copies / far_copies geometry. + */ +static struct md_rdev *read_balance(struct r10conf *conf, + struct r10bio *r10_bio, + int *max_sectors) +{ + const sector_t this_sector = r10_bio->sector; + int disk, slot; + int sectors = r10_bio->sectors; + int best_good_sectors; + sector_t new_distance, best_dist; + struct md_rdev *best_dist_rdev, *best_pending_rdev, *rdev = NULL; + int do_balance; + int best_dist_slot, best_pending_slot; + bool has_nonrot_disk = false; + unsigned int min_pending; + struct geom *geo = &conf->geo; + + raid10_find_phys(conf, r10_bio); + rcu_read_lock(); + best_dist_slot = -1; + min_pending = UINT_MAX; + best_dist_rdev = NULL; + best_pending_rdev = NULL; + best_dist = MaxSector; + best_good_sectors = 0; + do_balance = 1; + clear_bit(R10BIO_FailFast, &r10_bio->state); + /* + * Check if we can balance. We can balance on the whole + * device if no resync is going on (recovery is ok), or below + * the resync window. We take the first readable disk when + * above the resync window. + */ + if ((conf->mddev->recovery_cp < MaxSector + && (this_sector + sectors >= conf->next_resync)) || + (mddev_is_clustered(conf->mddev) && + md_cluster_ops->area_resyncing(conf->mddev, READ, this_sector, + this_sector + sectors))) + do_balance = 0; + + for (slot = 0; slot < conf->copies ; slot++) { + sector_t first_bad; + int bad_sectors; + sector_t dev_sector; + unsigned int pending; + bool nonrot; + + if (r10_bio->devs[slot].bio == IO_BLOCKED) + continue; + disk = r10_bio->devs[slot].devnum; + rdev = rcu_dereference(conf->mirrors[disk].replacement); + if (rdev == NULL || test_bit(Faulty, &rdev->flags) || + r10_bio->devs[slot].addr + sectors > + rdev->recovery_offset) { + /* + * Read replacement first to prevent reading both rdev + * and replacement as NULL during replacement replace + * rdev. + */ + smp_mb(); + rdev = rcu_dereference(conf->mirrors[disk].rdev); + } + if (rdev == NULL || + test_bit(Faulty, &rdev->flags)) + continue; + if (!test_bit(In_sync, &rdev->flags) && + r10_bio->devs[slot].addr + sectors > rdev->recovery_offset) + continue; + + dev_sector = r10_bio->devs[slot].addr; + if (is_badblock(rdev, dev_sector, sectors, + &first_bad, &bad_sectors)) { + if (best_dist < MaxSector) + /* Already have a better slot */ + continue; + if (first_bad <= dev_sector) { + /* Cannot read here. If this is the + * 'primary' device, then we must not read + * beyond 'bad_sectors' from another device. + */ + bad_sectors -= (dev_sector - first_bad); + if (!do_balance && sectors > bad_sectors) + sectors = bad_sectors; + if (best_good_sectors > sectors) + best_good_sectors = sectors; + } else { + sector_t good_sectors = + first_bad - dev_sector; + if (good_sectors > best_good_sectors) { + best_good_sectors = good_sectors; + best_dist_slot = slot; + best_dist_rdev = rdev; + } + if (!do_balance) + /* Must read from here */ + break; + } + continue; + } else + best_good_sectors = sectors; + + if (!do_balance) + break; + + nonrot = bdev_nonrot(rdev->bdev); + has_nonrot_disk |= nonrot; + pending = atomic_read(&rdev->nr_pending); + if (min_pending > pending && nonrot) { + min_pending = pending; + best_pending_slot = slot; + best_pending_rdev = rdev; + } + + if (best_dist_slot >= 0) + /* At least 2 disks to choose from so failfast is OK */ + set_bit(R10BIO_FailFast, &r10_bio->state); + /* This optimisation is debatable, and completely destroys + * sequential read speed for 'far copies' arrays. So only + * keep it for 'near' arrays, and review those later. + */ + if (geo->near_copies > 1 && !pending) + new_distance = 0; + + /* for far > 1 always use the lowest address */ + else if (geo->far_copies > 1) + new_distance = r10_bio->devs[slot].addr; + else + new_distance = abs(r10_bio->devs[slot].addr - + conf->mirrors[disk].head_position); + + if (new_distance < best_dist) { + best_dist = new_distance; + best_dist_slot = slot; + best_dist_rdev = rdev; + } + } + if (slot >= conf->copies) { + if (has_nonrot_disk) { + slot = best_pending_slot; + rdev = best_pending_rdev; + } else { + slot = best_dist_slot; + rdev = best_dist_rdev; + } + } + + if (slot >= 0) { + atomic_inc(&rdev->nr_pending); + r10_bio->read_slot = slot; + } else + rdev = NULL; + rcu_read_unlock(); + *max_sectors = best_good_sectors; + + return rdev; +} + +static void flush_pending_writes(struct r10conf *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); + raid1_prepare_flush_writes(conf->mddev->bitmap); + wake_up(&conf->wait_barrier); + + while (bio) { /* submit pending writes */ + struct bio *next = bio->bi_next; + + raid1_submit_write(bio); + bio = next; + cond_resched(); + } + 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. + */ + +static void raise_barrier(struct r10conf *conf, int force) +{ + write_seqlock_irq(&conf->resync_lock); + + if (WARN_ON_ONCE(force && !conf->barrier)) + force = false; + + /* Wait until no block IO is waiting (unless 'force') */ + wait_event_barrier(conf, force || !conf->nr_waiting); + + /* block any new IO from starting */ + WRITE_ONCE(conf->barrier, conf->barrier + 1); + + /* Now wait for all pending IO to complete */ + wait_event_barrier(conf, !atomic_read(&conf->nr_pending) && + conf->barrier < RESYNC_DEPTH); + + write_sequnlock_irq(&conf->resync_lock); +} + +static void lower_barrier(struct r10conf *conf) +{ + unsigned long flags; + + write_seqlock_irqsave(&conf->resync_lock, flags); + WRITE_ONCE(conf->barrier, conf->barrier - 1); + write_sequnlock_irqrestore(&conf->resync_lock, flags); + wake_up(&conf->wait_barrier); +} + +static bool stop_waiting_barrier(struct r10conf *conf) +{ + struct bio_list *bio_list = current->bio_list; + struct md_thread *thread; + + /* barrier is dropped */ + if (!conf->barrier) + return true; + + /* + * If there are already pending requests (preventing the barrier from + * rising completely), and the pre-process bio queue isn't empty, then + * don't wait, as we need to empty that queue to get the nr_pending + * count down. + */ + if (atomic_read(&conf->nr_pending) && bio_list && + (!bio_list_empty(&bio_list[0]) || !bio_list_empty(&bio_list[1]))) + return true; + + /* daemon thread must exist while handling io */ + thread = rcu_dereference_protected(conf->mddev->thread, true); + /* + * move on if io is issued from raid10d(), nr_pending is not released + * from original io(see handle_read_error()). All raise barrier is + * blocked until this io is done. + */ + if (thread->tsk == current) { + WARN_ON_ONCE(atomic_read(&conf->nr_pending) == 0); + return true; + } + + return false; +} + +static bool wait_barrier_nolock(struct r10conf *conf) +{ + unsigned int seq = read_seqbegin(&conf->resync_lock); + + if (READ_ONCE(conf->barrier)) + return false; + + atomic_inc(&conf->nr_pending); + if (!read_seqretry(&conf->resync_lock, seq)) + return true; + + if (atomic_dec_and_test(&conf->nr_pending)) + wake_up_barrier(conf); + + return false; +} + +static bool wait_barrier(struct r10conf *conf, bool nowait) +{ + bool ret = true; + + if (wait_barrier_nolock(conf)) + return true; + + write_seqlock_irq(&conf->resync_lock); + if (conf->barrier) { + /* Return false when nowait flag is set */ + if (nowait) { + ret = false; + } else { + conf->nr_waiting++; + raid10_log(conf->mddev, "wait barrier"); + wait_event_barrier(conf, stop_waiting_barrier(conf)); + conf->nr_waiting--; + } + if (!conf->nr_waiting) + wake_up(&conf->wait_barrier); + } + /* Only increment nr_pending when we wait */ + if (ret) + atomic_inc(&conf->nr_pending); + write_sequnlock_irq(&conf->resync_lock); + return ret; +} + +static void allow_barrier(struct r10conf *conf) +{ + if ((atomic_dec_and_test(&conf->nr_pending)) || + (conf->array_freeze_pending)) + wake_up_barrier(conf); +} + +static void freeze_array(struct r10conf *conf, int extra) +{ + /* stop syncio and normal IO and wait for everything to + * go quiet. + * We increment barrier and nr_waiting, and then + * wait until nr_pending match nr_queued+extra + * This is called in the context of one normal IO request + * that has failed. Thus any sync request that might be pending + * will be blocked by nr_pending, and we need to wait for + * pending IO requests to complete or be queued for re-try. + * Thus the number queued (nr_queued) plus this request (extra) + * must match the number of pending IOs (nr_pending) before + * we continue. + */ + write_seqlock_irq(&conf->resync_lock); + conf->array_freeze_pending++; + WRITE_ONCE(conf->barrier, conf->barrier + 1); + conf->nr_waiting++; + wait_event_barrier_cmd(conf, atomic_read(&conf->nr_pending) == + conf->nr_queued + extra, flush_pending_writes(conf)); + conf->array_freeze_pending--; + write_sequnlock_irq(&conf->resync_lock); +} + +static void unfreeze_array(struct r10conf *conf) +{ + /* reverse the effect of the freeze */ + write_seqlock_irq(&conf->resync_lock); + WRITE_ONCE(conf->barrier, conf->barrier - 1); + conf->nr_waiting--; + wake_up(&conf->wait_barrier); + write_sequnlock_irq(&conf->resync_lock); +} + +static sector_t choose_data_offset(struct r10bio *r10_bio, + struct md_rdev *rdev) +{ + if (!test_bit(MD_RECOVERY_RESHAPE, &rdev->mddev->recovery) || + test_bit(R10BIO_Previous, &r10_bio->state)) + return rdev->data_offset; + else + return rdev->new_data_offset; +} + +static void raid10_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 r10conf *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); + raid1_prepare_flush_writes(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(); + } + kfree(plug); +} + +/* + * 1. 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. + * 2. If IO spans the reshape position. Need to wait for reshape to pass. + */ +static bool regular_request_wait(struct mddev *mddev, struct r10conf *conf, + struct bio *bio, sector_t sectors) +{ + /* Bail out if REQ_NOWAIT is set for the bio */ + if (!wait_barrier(conf, bio->bi_opf & REQ_NOWAIT)) { + bio_wouldblock_error(bio); + return false; + } + while (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && + bio->bi_iter.bi_sector < conf->reshape_progress && + bio->bi_iter.bi_sector + sectors > conf->reshape_progress) { + allow_barrier(conf); + if (bio->bi_opf & REQ_NOWAIT) { + bio_wouldblock_error(bio); + return false; + } + raid10_log(conf->mddev, "wait reshape"); + wait_event(conf->wait_barrier, + conf->reshape_progress <= bio->bi_iter.bi_sector || + conf->reshape_progress >= bio->bi_iter.bi_sector + + sectors); + wait_barrier(conf, false); + } + return true; +} + +static void raid10_read_request(struct mddev *mddev, struct bio *bio, + struct r10bio *r10_bio, bool io_accounting) +{ + struct r10conf *conf = mddev->private; + struct bio *read_bio; + const enum req_op op = bio_op(bio); + const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC; + int max_sectors; + struct md_rdev *rdev; + char b[BDEVNAME_SIZE]; + int slot = r10_bio->read_slot; + struct md_rdev *err_rdev = NULL; + gfp_t gfp = GFP_NOIO; + + if (slot >= 0 && r10_bio->devs[slot].rdev) { + /* + * This is an error retry, but we cannot + * safely dereference the rdev in the r10_bio, + * we must use the one in conf. + * If it has already been disconnected (unlikely) + * we lose the device name in error messages. + */ + int disk; + /* + * As we are blocking raid10, it is a little safer to + * use __GFP_HIGH. + */ + gfp = GFP_NOIO | __GFP_HIGH; + + rcu_read_lock(); + disk = r10_bio->devs[slot].devnum; + err_rdev = rcu_dereference(conf->mirrors[disk].rdev); + if (err_rdev) + snprintf(b, sizeof(b), "%pg", err_rdev->bdev); + else { + strcpy(b, "???"); + /* This never gets dereferenced */ + err_rdev = r10_bio->devs[slot].rdev; + } + rcu_read_unlock(); + } + + if (!regular_request_wait(mddev, conf, bio, r10_bio->sectors)) + return; + rdev = read_balance(conf, r10_bio, &max_sectors); + if (!rdev) { + if (err_rdev) { + pr_crit_ratelimited("md/raid10:%s: %s: unrecoverable I/O read error for block %llu\n", + mdname(mddev), b, + (unsigned long long)r10_bio->sector); + } + raid_end_bio_io(r10_bio); + return; + } + if (err_rdev) + pr_err_ratelimited("md/raid10:%s: %pg: redirecting sector %llu to another mirror\n", + mdname(mddev), + rdev->bdev, + (unsigned long long)r10_bio->sector); + if (max_sectors < bio_sectors(bio)) { + struct bio *split = bio_split(bio, max_sectors, + gfp, &conf->bio_split); + bio_chain(split, bio); + allow_barrier(conf); + submit_bio_noacct(bio); + wait_barrier(conf, false); + bio = split; + r10_bio->master_bio = bio; + r10_bio->sectors = max_sectors; + } + slot = r10_bio->read_slot; + + if (io_accounting) { + md_account_bio(mddev, &bio); + r10_bio->master_bio = bio; + } + read_bio = bio_alloc_clone(rdev->bdev, bio, gfp, &mddev->bio_set); + + r10_bio->devs[slot].bio = read_bio; + r10_bio->devs[slot].rdev = rdev; + + read_bio->bi_iter.bi_sector = r10_bio->devs[slot].addr + + choose_data_offset(r10_bio, rdev); + read_bio->bi_end_io = raid10_end_read_request; + read_bio->bi_opf = op | do_sync; + if (test_bit(FailFast, &rdev->flags) && + test_bit(R10BIO_FailFast, &r10_bio->state)) + read_bio->bi_opf |= MD_FAILFAST; + read_bio->bi_private = r10_bio; + + if (mddev->gendisk) + trace_block_bio_remap(read_bio, disk_devt(mddev->gendisk), + r10_bio->sector); + submit_bio_noacct(read_bio); + return; +} + +static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio, + struct bio *bio, bool replacement, + int n_copy) +{ + const enum req_op op = bio_op(bio); + const blk_opf_t do_sync = bio->bi_opf & REQ_SYNC; + const blk_opf_t do_fua = bio->bi_opf & REQ_FUA; + unsigned long flags; + struct r10conf *conf = mddev->private; + struct md_rdev *rdev; + int devnum = r10_bio->devs[n_copy].devnum; + struct bio *mbio; + + if (replacement) { + rdev = conf->mirrors[devnum].replacement; + if (rdev == NULL) { + /* Replacement just got moved to main 'rdev' */ + smp_mb(); + rdev = conf->mirrors[devnum].rdev; + } + } else + rdev = conf->mirrors[devnum].rdev; + + mbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, &mddev->bio_set); + if (replacement) + r10_bio->devs[n_copy].repl_bio = mbio; + else + r10_bio->devs[n_copy].bio = mbio; + + mbio->bi_iter.bi_sector = (r10_bio->devs[n_copy].addr + + choose_data_offset(r10_bio, rdev)); + mbio->bi_end_io = raid10_end_write_request; + mbio->bi_opf = op | do_sync | do_fua; + if (!replacement && test_bit(FailFast, + &conf->mirrors[devnum].rdev->flags) + && enough(conf, devnum)) + mbio->bi_opf |= MD_FAILFAST; + mbio->bi_private = r10_bio; + + if (conf->mddev->gendisk) + trace_block_bio_remap(mbio, disk_devt(conf->mddev->gendisk), + r10_bio->sector); + /* flush_pending_writes() needs access to the rdev so...*/ + mbio->bi_bdev = (void *)rdev; + + atomic_inc(&r10_bio->remaining); + + if (!raid1_add_bio_to_plug(mddev, mbio, raid10_unplug, conf->copies)) { + 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); + } +} + +static struct md_rdev *dereference_rdev_and_rrdev(struct raid10_info *mirror, + struct md_rdev **prrdev) +{ + struct md_rdev *rdev, *rrdev; + + rrdev = rcu_dereference(mirror->replacement); + /* + * Read replacement first to prevent reading both rdev and + * replacement as NULL during replacement replace rdev. + */ + smp_mb(); + rdev = rcu_dereference(mirror->rdev); + if (rdev == rrdev) + rrdev = NULL; + + *prrdev = rrdev; + return rdev; +} + +static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio) +{ + int i; + struct r10conf *conf = mddev->private; + struct md_rdev *blocked_rdev; + +retry_wait: + blocked_rdev = NULL; + rcu_read_lock(); + for (i = 0; i < conf->copies; i++) { + struct md_rdev *rdev, *rrdev; + + rdev = dereference_rdev_and_rrdev(&conf->mirrors[i], &rrdev); + if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { + atomic_inc(&rdev->nr_pending); + blocked_rdev = rdev; + break; + } + if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) { + atomic_inc(&rrdev->nr_pending); + blocked_rdev = rrdev; + break; + } + + if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) { + sector_t first_bad; + sector_t dev_sector = r10_bio->devs[i].addr; + int bad_sectors; + int is_bad; + + /* + * Discard request doesn't care the write result + * so it doesn't need to wait blocked disk here. + */ + if (!r10_bio->sectors) + continue; + + is_bad = is_badblock(rdev, dev_sector, r10_bio->sectors, + &first_bad, &bad_sectors); + if (is_bad < 0) { + /* + * Mustn't write here until the bad block + * is acknowledged + */ + atomic_inc(&rdev->nr_pending); + set_bit(BlockedBadBlocks, &rdev->flags); + blocked_rdev = rdev; + break; + } + } + } + rcu_read_unlock(); + + if (unlikely(blocked_rdev)) { + /* Have to wait for this device to get unblocked, then retry */ + allow_barrier(conf); + raid10_log(conf->mddev, "%s wait rdev %d blocked", + __func__, blocked_rdev->raid_disk); + md_wait_for_blocked_rdev(blocked_rdev, mddev); + wait_barrier(conf, false); + goto retry_wait; + } +} + +static void raid10_write_request(struct mddev *mddev, struct bio *bio, + struct r10bio *r10_bio) +{ + struct r10conf *conf = mddev->private; + int i; + sector_t sectors; + int max_sectors; + + if ((mddev_is_clustered(mddev) && + md_cluster_ops->area_resyncing(mddev, WRITE, + bio->bi_iter.bi_sector, + bio_end_sector(bio)))) { + DEFINE_WAIT(w); + /* Bail out if REQ_NOWAIT is set for the bio */ + 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); + } + + sectors = r10_bio->sectors; + if (!regular_request_wait(mddev, conf, bio, sectors)) + return; + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && + (mddev->reshape_backwards + ? (bio->bi_iter.bi_sector < conf->reshape_safe && + bio->bi_iter.bi_sector + sectors > conf->reshape_progress) + : (bio->bi_iter.bi_sector + sectors > conf->reshape_safe && + bio->bi_iter.bi_sector < conf->reshape_progress))) { + /* Need to update reshape_position in metadata */ + mddev->reshape_position = conf->reshape_progress; + set_mask_bits(&mddev->sb_flags, 0, + BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); + md_wakeup_thread(mddev->thread); + if (bio->bi_opf & REQ_NOWAIT) { + allow_barrier(conf); + bio_wouldblock_error(bio); + return; + } + raid10_log(conf->mddev, "wait reshape metadata"); + wait_event(mddev->sb_wait, + !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)); + + conf->reshape_safe = mddev->reshape_position; + } + + /* 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 to those blocks. This potentially requires several + * writes to write around the bad blocks. Each set of writes + * gets its own r10_bio with a set of bios attached. + */ + + r10_bio->read_slot = -1; /* make sure repl_bio gets freed */ + raid10_find_phys(conf, r10_bio); + + wait_blocked_dev(mddev, r10_bio); + + rcu_read_lock(); + max_sectors = r10_bio->sectors; + + for (i = 0; i < conf->copies; i++) { + int d = r10_bio->devs[i].devnum; + struct md_rdev *rdev, *rrdev; + + rdev = dereference_rdev_and_rrdev(&conf->mirrors[d], &rrdev); + if (rdev && (test_bit(Faulty, &rdev->flags))) + rdev = NULL; + if (rrdev && (test_bit(Faulty, &rrdev->flags))) + rrdev = NULL; + + r10_bio->devs[i].bio = NULL; + r10_bio->devs[i].repl_bio = NULL; + + if (!rdev && !rrdev) { + set_bit(R10BIO_Degraded, &r10_bio->state); + continue; + } + if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) { + sector_t first_bad; + sector_t dev_sector = r10_bio->devs[i].addr; + int bad_sectors; + int is_bad; + + is_bad = is_badblock(rdev, dev_sector, max_sectors, + &first_bad, &bad_sectors); + if (is_bad && first_bad <= dev_sector) { + /* Cannot write here at all */ + bad_sectors -= (dev_sector - first_bad); + if (bad_sectors < max_sectors) + /* Mustn't write more than bad_sectors + * to other devices yet + */ + max_sectors = bad_sectors; + /* We don't set R10BIO_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 - dev_sector; + if (good_sectors < max_sectors) + max_sectors = good_sectors; + } + } + if (rdev) { + r10_bio->devs[i].bio = bio; + atomic_inc(&rdev->nr_pending); + } + if (rrdev) { + r10_bio->devs[i].repl_bio = bio; + atomic_inc(&rrdev->nr_pending); + } + } + rcu_read_unlock(); + + if (max_sectors < r10_bio->sectors) + r10_bio->sectors = max_sectors; + + if (r10_bio->sectors < bio_sectors(bio)) { + struct bio *split = bio_split(bio, r10_bio->sectors, + GFP_NOIO, &conf->bio_split); + bio_chain(split, bio); + allow_barrier(conf); + submit_bio_noacct(bio); + wait_barrier(conf, false); + bio = split; + r10_bio->master_bio = bio; + } + + md_account_bio(mddev, &bio); + r10_bio->master_bio = bio; + atomic_set(&r10_bio->remaining, 1); + md_bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0); + + for (i = 0; i < conf->copies; i++) { + if (r10_bio->devs[i].bio) + raid10_write_one_disk(mddev, r10_bio, bio, false, i); + if (r10_bio->devs[i].repl_bio) + raid10_write_one_disk(mddev, r10_bio, bio, true, i); + } + one_write_done(r10_bio); +} + +static void __make_request(struct mddev *mddev, struct bio *bio, int sectors) +{ + struct r10conf *conf = mddev->private; + struct r10bio *r10_bio; + + r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO); + + r10_bio->master_bio = bio; + r10_bio->sectors = sectors; + + r10_bio->mddev = mddev; + r10_bio->sector = bio->bi_iter.bi_sector; + r10_bio->state = 0; + r10_bio->read_slot = -1; + memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * + conf->geo.raid_disks); + + if (bio_data_dir(bio) == READ) + raid10_read_request(mddev, bio, r10_bio, true); + else + raid10_write_request(mddev, bio, r10_bio); +} + +static void raid_end_discard_bio(struct r10bio *r10bio) +{ + struct r10conf *conf = r10bio->mddev->private; + struct r10bio *first_r10bio; + + while (atomic_dec_and_test(&r10bio->remaining)) { + + allow_barrier(conf); + + if (!test_bit(R10BIO_Discard, &r10bio->state)) { + first_r10bio = (struct r10bio *)r10bio->master_bio; + free_r10bio(r10bio); + r10bio = first_r10bio; + } else { + md_write_end(r10bio->mddev); + bio_endio(r10bio->master_bio); + free_r10bio(r10bio); + break; + } + } +} + +static void raid10_end_discard_request(struct bio *bio) +{ + struct r10bio *r10_bio = bio->bi_private; + struct r10conf *conf = r10_bio->mddev->private; + struct md_rdev *rdev = NULL; + int dev; + int slot, repl; + + /* + * We don't care the return value of discard bio + */ + if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) + set_bit(R10BIO_Uptodate, &r10_bio->state); + + dev = find_bio_disk(conf, r10_bio, bio, &slot, &repl); + if (repl) + rdev = conf->mirrors[dev].replacement; + if (!rdev) { + /* + * raid10_remove_disk uses smp_mb to make sure rdev is set to + * replacement before setting replacement to NULL. It can read + * rdev first without barrier protect even replacement is NULL + */ + smp_rmb(); + rdev = conf->mirrors[dev].rdev; + } + + raid_end_discard_bio(r10_bio); + rdev_dec_pending(rdev, conf->mddev); +} + +/* + * There are some limitations to handle discard bio + * 1st, the discard size is bigger than stripe_size*2. + * 2st, if the discard bio spans reshape progress, we use the old way to + * handle discard bio + */ +static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) +{ + struct r10conf *conf = mddev->private; + struct geom *geo = &conf->geo; + int far_copies = geo->far_copies; + bool first_copy = true; + struct r10bio *r10_bio, *first_r10bio; + struct bio *split; + int disk; + sector_t chunk; + unsigned int stripe_size; + unsigned int stripe_data_disks; + sector_t split_size; + sector_t bio_start, bio_end; + sector_t first_stripe_index, last_stripe_index; + sector_t start_disk_offset; + unsigned int start_disk_index; + sector_t end_disk_offset; + unsigned int end_disk_index; + unsigned int remainder; + + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + return -EAGAIN; + + if (WARN_ON_ONCE(bio->bi_opf & REQ_NOWAIT)) { + bio_wouldblock_error(bio); + return 0; + } + wait_barrier(conf, false); + + /* + * Check reshape again to avoid reshape happens after checking + * MD_RECOVERY_RESHAPE and before wait_barrier + */ + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + goto out; + + if (geo->near_copies) + stripe_data_disks = geo->raid_disks / geo->near_copies + + geo->raid_disks % geo->near_copies; + else + stripe_data_disks = geo->raid_disks; + + stripe_size = stripe_data_disks << geo->chunk_shift; + + bio_start = bio->bi_iter.bi_sector; + bio_end = bio_end_sector(bio); + + /* + * Maybe one discard bio is smaller than strip size or across one + * stripe and discard region is larger than one stripe size. For far + * offset layout, if the discard region is not aligned with stripe + * size, there is hole when we submit discard bio to member disk. + * For simplicity, we only handle discard bio which discard region + * is bigger than stripe_size * 2 + */ + if (bio_sectors(bio) < stripe_size*2) + goto out; + + /* + * Keep bio aligned with strip size. + */ + div_u64_rem(bio_start, stripe_size, &remainder); + if (remainder) { + split_size = stripe_size - remainder; + split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split); + bio_chain(split, bio); + allow_barrier(conf); + /* Resend the fist split part */ + submit_bio_noacct(split); + wait_barrier(conf, false); + } + div_u64_rem(bio_end, stripe_size, &remainder); + if (remainder) { + split_size = bio_sectors(bio) - remainder; + split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split); + bio_chain(split, bio); + allow_barrier(conf); + /* Resend the second split part */ + submit_bio_noacct(bio); + bio = split; + wait_barrier(conf, false); + } + + bio_start = bio->bi_iter.bi_sector; + bio_end = bio_end_sector(bio); + + /* + * Raid10 uses chunk as the unit to store data. It's similar like raid0. + * One stripe contains the chunks from all member disk (one chunk from + * one disk at the same HBA address). For layout detail, see 'man md 4' + */ + chunk = bio_start >> geo->chunk_shift; + chunk *= geo->near_copies; + first_stripe_index = chunk; + start_disk_index = sector_div(first_stripe_index, geo->raid_disks); + if (geo->far_offset) + first_stripe_index *= geo->far_copies; + start_disk_offset = (bio_start & geo->chunk_mask) + + (first_stripe_index << geo->chunk_shift); + + chunk = bio_end >> geo->chunk_shift; + chunk *= geo->near_copies; + last_stripe_index = chunk; + end_disk_index = sector_div(last_stripe_index, geo->raid_disks); + if (geo->far_offset) + last_stripe_index *= geo->far_copies; + end_disk_offset = (bio_end & geo->chunk_mask) + + (last_stripe_index << geo->chunk_shift); + +retry_discard: + r10_bio = mempool_alloc(&conf->r10bio_pool, GFP_NOIO); + r10_bio->mddev = mddev; + r10_bio->state = 0; + r10_bio->sectors = 0; + memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * geo->raid_disks); + wait_blocked_dev(mddev, r10_bio); + + /* + * For far layout it needs more than one r10bio to cover all regions. + * Inspired by raid10_sync_request, we can use the first r10bio->master_bio + * to record the discard bio. Other r10bio->master_bio record the first + * r10bio. The first r10bio only release after all other r10bios finish. + * The discard bio returns only first r10bio finishes + */ + if (first_copy) { + r10_bio->master_bio = bio; + set_bit(R10BIO_Discard, &r10_bio->state); + first_copy = false; + first_r10bio = r10_bio; + } else + r10_bio->master_bio = (struct bio *)first_r10bio; + + /* + * first select target devices under rcu_lock and + * inc refcount on their rdev. Record them by setting + * bios[x] to bio + */ + rcu_read_lock(); + for (disk = 0; disk < geo->raid_disks; disk++) { + struct md_rdev *rdev, *rrdev; + + rdev = dereference_rdev_and_rrdev(&conf->mirrors[disk], &rrdev); + r10_bio->devs[disk].bio = NULL; + r10_bio->devs[disk].repl_bio = NULL; + + if (rdev && (test_bit(Faulty, &rdev->flags))) + rdev = NULL; + if (rrdev && (test_bit(Faulty, &rrdev->flags))) + rrdev = NULL; + if (!rdev && !rrdev) + continue; + + if (rdev) { + r10_bio->devs[disk].bio = bio; + atomic_inc(&rdev->nr_pending); + } + if (rrdev) { + r10_bio->devs[disk].repl_bio = bio; + atomic_inc(&rrdev->nr_pending); + } + } + rcu_read_unlock(); + + atomic_set(&r10_bio->remaining, 1); + for (disk = 0; disk < geo->raid_disks; disk++) { + sector_t dev_start, dev_end; + struct bio *mbio, *rbio = NULL; + + /* + * Now start to calculate the start and end address for each disk. + * The space between dev_start and dev_end is the discard region. + * + * For dev_start, it needs to consider three conditions: + * 1st, the disk is before start_disk, you can imagine the disk in + * the next stripe. So the dev_start is the start address of next + * stripe. + * 2st, the disk is after start_disk, it means the disk is at the + * same stripe of first disk + * 3st, the first disk itself, we can use start_disk_offset directly + */ + if (disk < start_disk_index) + dev_start = (first_stripe_index + 1) * mddev->chunk_sectors; + else if (disk > start_disk_index) + dev_start = first_stripe_index * mddev->chunk_sectors; + else + dev_start = start_disk_offset; + + if (disk < end_disk_index) + dev_end = (last_stripe_index + 1) * mddev->chunk_sectors; + else if (disk > end_disk_index) + dev_end = last_stripe_index * mddev->chunk_sectors; + else + dev_end = end_disk_offset; + + /* + * It only handles discard bio which size is >= stripe size, so + * dev_end > dev_start all the time. + * It doesn't need to use rcu lock to get rdev here. We already + * add rdev->nr_pending in the first loop. + */ + if (r10_bio->devs[disk].bio) { + struct md_rdev *rdev = conf->mirrors[disk].rdev; + mbio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, + &mddev->bio_set); + mbio->bi_end_io = raid10_end_discard_request; + mbio->bi_private = r10_bio; + r10_bio->devs[disk].bio = mbio; + r10_bio->devs[disk].devnum = disk; + atomic_inc(&r10_bio->remaining); + md_submit_discard_bio(mddev, rdev, mbio, + dev_start + choose_data_offset(r10_bio, rdev), + dev_end - dev_start); + bio_endio(mbio); + } + if (r10_bio->devs[disk].repl_bio) { + struct md_rdev *rrdev = conf->mirrors[disk].replacement; + rbio = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, + &mddev->bio_set); + rbio->bi_end_io = raid10_end_discard_request; + rbio->bi_private = r10_bio; + r10_bio->devs[disk].repl_bio = rbio; + r10_bio->devs[disk].devnum = disk; + atomic_inc(&r10_bio->remaining); + md_submit_discard_bio(mddev, rrdev, rbio, + dev_start + choose_data_offset(r10_bio, rrdev), + dev_end - dev_start); + bio_endio(rbio); + } + } + + if (!geo->far_offset && --far_copies) { + first_stripe_index += geo->stride >> geo->chunk_shift; + start_disk_offset += geo->stride; + last_stripe_index += geo->stride >> geo->chunk_shift; + end_disk_offset += geo->stride; + atomic_inc(&first_r10bio->remaining); + raid_end_discard_bio(r10_bio); + wait_barrier(conf, false); + goto retry_discard; + } + + raid_end_discard_bio(r10_bio); + + return 0; +out: + allow_barrier(conf); + return -EAGAIN; +} + +static bool raid10_make_request(struct mddev *mddev, struct bio *bio) +{ + struct r10conf *conf = mddev->private; + sector_t chunk_mask = (conf->geo.chunk_mask & conf->prev.chunk_mask); + int chunk_sects = chunk_mask + 1; + int sectors = bio_sectors(bio); + + if (unlikely(bio->bi_opf & REQ_PREFLUSH) + && md_flush_request(mddev, bio)) + return true; + + if (!md_write_start(mddev, bio)) + return false; + + if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) + if (!raid10_handle_discard(mddev, bio)) + return true; + + /* + * If this request crosses a chunk boundary, we need to split + * it. + */ + if (unlikely((bio->bi_iter.bi_sector & chunk_mask) + + sectors > chunk_sects + && (conf->geo.near_copies < conf->geo.raid_disks + || conf->prev.near_copies < + conf->prev.raid_disks))) + sectors = chunk_sects - + (bio->bi_iter.bi_sector & + (chunk_sects - 1)); + __make_request(mddev, bio, sectors); + + /* In case raid10d snuck in to freeze_array */ + wake_up_barrier(conf); + return true; +} + +static void raid10_status(struct seq_file *seq, struct mddev *mddev) +{ + struct r10conf *conf = mddev->private; + int i; + + if (conf->geo.near_copies < conf->geo.raid_disks) + seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2); + if (conf->geo.near_copies > 1) + seq_printf(seq, " %d near-copies", conf->geo.near_copies); + if (conf->geo.far_copies > 1) { + if (conf->geo.far_offset) + seq_printf(seq, " %d offset-copies", conf->geo.far_copies); + else + seq_printf(seq, " %d far-copies", conf->geo.far_copies); + if (conf->geo.far_set_size != conf->geo.raid_disks) + seq_printf(seq, " %d devices per set", conf->geo.far_set_size); + } + seq_printf(seq, " [%d/%d] [", conf->geo.raid_disks, + conf->geo.raid_disks - mddev->degraded); + rcu_read_lock(); + for (i = 0; i < conf->geo.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, "]"); +} + +/* check if there are enough drives for + * every block to appear on atleast one. + * Don't consider the device numbered 'ignore' + * as we might be about to remove it. + */ +static int _enough(struct r10conf *conf, int previous, int ignore) +{ + int first = 0; + int has_enough = 0; + int disks, ncopies; + if (previous) { + disks = conf->prev.raid_disks; + ncopies = conf->prev.near_copies; + } else { + disks = conf->geo.raid_disks; + ncopies = conf->geo.near_copies; + } + + rcu_read_lock(); + do { + int n = conf->copies; + int cnt = 0; + int this = first; + while (n--) { + struct md_rdev *rdev; + if (this != ignore && + (rdev = rcu_dereference(conf->mirrors[this].rdev)) && + test_bit(In_sync, &rdev->flags)) + cnt++; + this = (this+1) % disks; + } + if (cnt == 0) + goto out; + first = (first + ncopies) % disks; + } while (first != 0); + has_enough = 1; +out: + rcu_read_unlock(); + return has_enough; +} + +static int enough(struct r10conf *conf, int ignore) +{ + /* when calling 'enough', both 'prev' and 'geo' must + * be stable. + * This is ensured if ->reconfig_mutex or ->device_lock + * is held. + */ + return _enough(conf, 0, ignore) && + _enough(conf, 1, ignore); +} + +/** + * raid10_error() - RAID10 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. + * 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 raid10_error(struct mddev *mddev, struct md_rdev *rdev) +{ + struct r10conf *conf = mddev->private; + unsigned long flags; + + spin_lock_irqsave(&conf->device_lock, flags); + + if (test_bit(In_sync, &rdev->flags) && !enough(conf, rdev->raid_disk)) { + set_bit(MD_BROKEN, &mddev->flags); + + if (!mddev->fail_last_dev) { + spin_unlock_irqrestore(&conf->device_lock, flags); + return; + } + } + if (test_and_clear_bit(In_sync, &rdev->flags)) + mddev->degraded++; + + set_bit(MD_RECOVERY_INTR, &mddev->recovery); + set_bit(Blocked, &rdev->flags); + set_bit(Faulty, &rdev->flags); + set_mask_bits(&mddev->sb_flags, 0, + BIT(MD_SB_CHANGE_DEVS) | BIT(MD_SB_CHANGE_PENDING)); + spin_unlock_irqrestore(&conf->device_lock, flags); + pr_crit("md/raid10:%s: Disk failure on %pg, disabling device.\n" + "md/raid10:%s: Operation continuing on %d devices.\n", + mdname(mddev), rdev->bdev, + mdname(mddev), conf->geo.raid_disks - mddev->degraded); +} + +static void print_conf(struct r10conf *conf) +{ + int i; + struct md_rdev *rdev; + + pr_debug("RAID10 conf printout:\n"); + if (!conf) { + pr_debug("(!conf)\n"); + return; + } + pr_debug(" --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded, + conf->geo.raid_disks); + + /* This is only called with ->reconfix_mutex held, so + * rcu protection of rdev is not needed */ + for (i = 0; i < conf->geo.raid_disks; i++) { + rdev = 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); + } +} + +static void close_sync(struct r10conf *conf) +{ + wait_barrier(conf, false); + allow_barrier(conf); + + mempool_exit(&conf->r10buf_pool); +} + +static int raid10_spare_active(struct mddev *mddev) +{ + int i; + struct r10conf *conf = mddev->private; + struct raid10_info *tmp; + int count = 0; + unsigned long flags; + + /* + * Find all non-in_sync disks within the RAID10 configuration + * and mark them in_sync + */ + for (i = 0; i < conf->geo.raid_disks; i++) { + tmp = conf->mirrors + i; + if (tmp->replacement + && tmp->replacement->recovery_offset == MaxSector + && !test_bit(Faulty, &tmp->replacement->flags) + && !test_and_set_bit(In_sync, &tmp->replacement->flags)) { + /* Replacement has just become active */ + if (!tmp->rdev + || !test_and_clear_bit(In_sync, &tmp->rdev->flags)) + count++; + if (tmp->rdev) { + /* Replaced device not technically faulty, + * but we need to be sure it gets removed + * and never re-added. + */ + set_bit(Faulty, &tmp->rdev->flags); + sysfs_notify_dirent_safe( + tmp->rdev->sysfs_state); + } + sysfs_notify_dirent_safe(tmp->replacement->sysfs_state); + } else if (tmp->rdev + && tmp->rdev->recovery_offset == MaxSector + && !test_bit(Faulty, &tmp->rdev->flags) + && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { + count++; + sysfs_notify_dirent_safe(tmp->rdev->sysfs_state); + } + } + spin_lock_irqsave(&conf->device_lock, flags); + mddev->degraded -= count; + spin_unlock_irqrestore(&conf->device_lock, flags); + + print_conf(conf); + return count; +} + +static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev) +{ + struct r10conf *conf = mddev->private; + int err = -EEXIST; + int mirror, repl_slot = -1; + int first = 0; + int last = conf->geo.raid_disks - 1; + struct raid10_info *p; + + if (mddev->recovery_cp < MaxSector) + /* only hot-add to in-sync arrays, as recovery is + * very different from resync + */ + return -EBUSY; + if (rdev->saved_raid_disk < 0 && !_enough(conf, 1, -1)) + return -EINVAL; + + if (md_integrity_add_rdev(rdev, mddev)) + return -ENXIO; + + if (rdev->raid_disk >= 0) + first = last = rdev->raid_disk; + + if (rdev->saved_raid_disk >= first && + rdev->saved_raid_disk < conf->geo.raid_disks && + conf->mirrors[rdev->saved_raid_disk].rdev == NULL) + mirror = rdev->saved_raid_disk; + else + mirror = first; + for ( ; mirror <= last ; mirror++) { + p = &conf->mirrors[mirror]; + if (p->recovery_disabled == mddev->recovery_disabled) + continue; + if (p->rdev) { + if (test_bit(WantReplacement, &p->rdev->flags) && + p->replacement == NULL && repl_slot < 0) + repl_slot = mirror; + continue; + } + + if (mddev->gendisk) + disk_stack_limits(mddev->gendisk, rdev->bdev, + rdev->data_offset << 9); + + p->head_position = 0; + p->recovery_disabled = mddev->recovery_disabled - 1; + rdev->raid_disk = mirror; + err = 0; + if (rdev->saved_raid_disk != mirror) + conf->fullsync = 1; + rcu_assign_pointer(p->rdev, rdev); + break; + } + + if (err && repl_slot >= 0) { + p = &conf->mirrors[repl_slot]; + clear_bit(In_sync, &rdev->flags); + set_bit(Replacement, &rdev->flags); + rdev->raid_disk = repl_slot; + err = 0; + if (mddev->gendisk) + disk_stack_limits(mddev->gendisk, rdev->bdev, + rdev->data_offset << 9); + conf->fullsync = 1; + rcu_assign_pointer(p->replacement, rdev); + } + + print_conf(conf); + return err; +} + +static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev) +{ + struct r10conf *conf = mddev->private; + int err = 0; + int number = rdev->raid_disk; + struct md_rdev **rdevp; + struct raid10_info *p; + + print_conf(conf); + if (unlikely(number >= mddev->raid_disks)) + return 0; + p = conf->mirrors + number; + if (rdev == p->rdev) + rdevp = &p->rdev; + else if (rdev == p->replacement) + rdevp = &p->replacement; + else + return 0; + + 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 != p->recovery_disabled && + (!p->replacement || p->replacement == rdev) && + number < conf->geo.raid_disks && + enough(conf, -1)) { + err = -EBUSY; + goto abort; + } + *rdevp = NULL; + if (!test_bit(RemoveSynchronized, &rdev->flags)) { + synchronize_rcu(); + if (atomic_read(&rdev->nr_pending)) { + /* lost the race, try later */ + err = -EBUSY; + *rdevp = rdev; + goto abort; + } + } + if (p->replacement) { + /* We must have just cleared 'rdev' */ + p->rdev = p->replacement; + clear_bit(Replacement, &p->replacement->flags); + smp_mb(); /* Make sure other CPUs may see both as identical + * but will never see neither -- if they are careful. + */ + p->replacement = NULL; + } + + clear_bit(WantReplacement, &rdev->flags); + err = md_integrity_register(mddev); + +abort: + + print_conf(conf); + return err; +} + +static void __end_sync_read(struct r10bio *r10_bio, struct bio *bio, int d) +{ + struct r10conf *conf = r10_bio->mddev->private; + + if (!bio->bi_status) + set_bit(R10BIO_Uptodate, &r10_bio->state); + else + /* The write handler will notice the lack of + * R10BIO_Uptodate and record any errors etc + */ + atomic_add(r10_bio->sectors, + &conf->mirrors[d].rdev->corrected_errors); + + /* for reconstruct, we always reschedule after a read. + * for resync, only after all reads + */ + rdev_dec_pending(conf->mirrors[d].rdev, conf->mddev); + if (test_bit(R10BIO_IsRecover, &r10_bio->state) || + atomic_dec_and_test(&r10_bio->remaining)) { + /* we have read all the blocks, + * do the comparison in process context in raid10d + */ + reschedule_retry(r10_bio); + } +} + +static void end_sync_read(struct bio *bio) +{ + struct r10bio *r10_bio = get_resync_r10bio(bio); + struct r10conf *conf = r10_bio->mddev->private; + int d = find_bio_disk(conf, r10_bio, bio, NULL, NULL); + + __end_sync_read(r10_bio, bio, d); +} + +static void end_reshape_read(struct bio *bio) +{ + /* reshape read bio isn't allocated from r10buf_pool */ + struct r10bio *r10_bio = bio->bi_private; + + __end_sync_read(r10_bio, bio, r10_bio->read_slot); +} + +static void end_sync_request(struct r10bio *r10_bio) +{ + struct mddev *mddev = r10_bio->mddev; + + while (atomic_dec_and_test(&r10_bio->remaining)) { + if (r10_bio->master_bio == NULL) { + /* the primary of several recovery bios */ + sector_t s = r10_bio->sectors; + if (test_bit(R10BIO_MadeGood, &r10_bio->state) || + test_bit(R10BIO_WriteError, &r10_bio->state)) + reschedule_retry(r10_bio); + else + put_buf(r10_bio); + md_done_sync(mddev, s, 1); + break; + } else { + struct r10bio *r10_bio2 = (struct r10bio *)r10_bio->master_bio; + if (test_bit(R10BIO_MadeGood, &r10_bio->state) || + test_bit(R10BIO_WriteError, &r10_bio->state)) + reschedule_retry(r10_bio); + else + put_buf(r10_bio); + r10_bio = r10_bio2; + } + } +} + +static void end_sync_write(struct bio *bio) +{ + struct r10bio *r10_bio = get_resync_r10bio(bio); + struct mddev *mddev = r10_bio->mddev; + struct r10conf *conf = mddev->private; + int d; + sector_t first_bad; + int bad_sectors; + int slot; + int repl; + struct md_rdev *rdev = NULL; + + d = find_bio_disk(conf, r10_bio, bio, &slot, &repl); + if (repl) + rdev = conf->mirrors[d].replacement; + else + rdev = conf->mirrors[d].rdev; + + if (bio->bi_status) { + if (repl) + md_error(mddev, rdev); + else { + set_bit(WriteErrorSeen, &rdev->flags); + if (!test_and_set_bit(WantReplacement, &rdev->flags)) + set_bit(MD_RECOVERY_NEEDED, + &rdev->mddev->recovery); + set_bit(R10BIO_WriteError, &r10_bio->state); + } + } else if (is_badblock(rdev, + r10_bio->devs[slot].addr, + r10_bio->sectors, + &first_bad, &bad_sectors)) + set_bit(R10BIO_MadeGood, &r10_bio->state); + + rdev_dec_pending(rdev, mddev); + + end_sync_request(r10_bio); +} + +/* + * Note: sync and recover and handled very differently for raid10 + * This code is for resync. + * For resync, we read through virtual addresses and read all blocks. + * If there is any error, we schedule a write. The lowest numbered + * drive is authoritative. + * However requests come for physical address, so we need to map. + * For every physical address there are raid_disks/copies virtual addresses, + * which is always are least one, but is not necessarly an integer. + * This means that a physical address can span multiple chunks, so we may + * have to submit multiple io requests for a single sync request. + */ +/* + * We check if all blocks are in-sync and only write to blocks that + * aren't in sync + */ +static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio) +{ + struct r10conf *conf = mddev->private; + int i, first; + struct bio *tbio, *fbio; + int vcnt; + struct page **tpages, **fpages; + + atomic_set(&r10_bio->remaining, 1); + + /* find the first device with a block */ + for (i=0; i<conf->copies; i++) + if (!r10_bio->devs[i].bio->bi_status) + break; + + if (i == conf->copies) + goto done; + + first = i; + fbio = r10_bio->devs[i].bio; + fbio->bi_iter.bi_size = r10_bio->sectors << 9; + fbio->bi_iter.bi_idx = 0; + fpages = get_resync_pages(fbio)->pages; + + vcnt = (r10_bio->sectors + (PAGE_SIZE >> 9) - 1) >> (PAGE_SHIFT - 9); + /* now find blocks with errors */ + for (i=0 ; i < conf->copies ; i++) { + int j, d; + struct md_rdev *rdev; + struct resync_pages *rp; + + tbio = r10_bio->devs[i].bio; + + if (tbio->bi_end_io != end_sync_read) + continue; + if (i == first) + continue; + + tpages = get_resync_pages(tbio)->pages; + d = r10_bio->devs[i].devnum; + rdev = conf->mirrors[d].rdev; + if (!r10_bio->devs[i].bio->bi_status) { + /* We know that the bi_io_vec layout is the same for + * both 'first' and 'i', so we just compare them. + * All vec entries are PAGE_SIZE; + */ + int sectors = r10_bio->sectors; + for (j = 0; j < vcnt; j++) { + int len = PAGE_SIZE; + if (sectors < (len / 512)) + len = sectors * 512; + if (memcmp(page_address(fpages[j]), + page_address(tpages[j]), + len)) + break; + sectors -= len/512; + } + if (j == vcnt) + continue; + atomic64_add(r10_bio->sectors, &mddev->resync_mismatches); + if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) + /* Don't fix anything. */ + continue; + } else if (test_bit(FailFast, &rdev->flags)) { + /* Just give up on this device */ + md_error(rdev->mddev, rdev); + continue; + } + /* Ok, we need to write this bio, either to correct an + * inconsistency or to correct an unreadable block. + * First we need to fixup bv_offset, bv_len and + * bi_vecs, as the read request might have corrupted these + */ + rp = get_resync_pages(tbio); + bio_reset(tbio, conf->mirrors[d].rdev->bdev, REQ_OP_WRITE); + + md_bio_reset_resync_pages(tbio, rp, fbio->bi_iter.bi_size); + + rp->raid_bio = r10_bio; + tbio->bi_private = rp; + tbio->bi_iter.bi_sector = r10_bio->devs[i].addr; + tbio->bi_end_io = end_sync_write; + + bio_copy_data(tbio, fbio); + + atomic_inc(&conf->mirrors[d].rdev->nr_pending); + atomic_inc(&r10_bio->remaining); + md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio)); + + if (test_bit(FailFast, &conf->mirrors[d].rdev->flags)) + tbio->bi_opf |= MD_FAILFAST; + tbio->bi_iter.bi_sector += conf->mirrors[d].rdev->data_offset; + submit_bio_noacct(tbio); + } + + /* Now write out to any replacement devices + * that are active + */ + for (i = 0; i < conf->copies; i++) { + int d; + + tbio = r10_bio->devs[i].repl_bio; + if (!tbio || !tbio->bi_end_io) + continue; + if (r10_bio->devs[i].bio->bi_end_io != end_sync_write + && r10_bio->devs[i].bio != fbio) + bio_copy_data(tbio, fbio); + d = r10_bio->devs[i].devnum; + atomic_inc(&r10_bio->remaining); + md_sync_acct(conf->mirrors[d].replacement->bdev, + bio_sectors(tbio)); + submit_bio_noacct(tbio); + } + +done: + if (atomic_dec_and_test(&r10_bio->remaining)) { + md_done_sync(mddev, r10_bio->sectors, 1); + put_buf(r10_bio); + } +} + +/* + * Now for the recovery code. + * Recovery happens across physical sectors. + * We recover all non-is_sync drives by finding the virtual address of + * each, and then choose a working drive that also has that virt address. + * There is a separate r10_bio for each non-in_sync drive. + * Only the first two slots are in use. The first for reading, + * The second for writing. + * + */ +static void fix_recovery_read_error(struct r10bio *r10_bio) +{ + /* We got a read error during recovery. + * We repeat the read in smaller page-sized sections. + * If a read succeeds, write it to the new device or record + * a bad block if we cannot. + * If a read fails, record a bad block on both old and + * new devices. + */ + struct mddev *mddev = r10_bio->mddev; + struct r10conf *conf = mddev->private; + struct bio *bio = r10_bio->devs[0].bio; + sector_t sect = 0; + int sectors = r10_bio->sectors; + int idx = 0; + int dr = r10_bio->devs[0].devnum; + int dw = r10_bio->devs[1].devnum; + struct page **pages = get_resync_pages(bio)->pages; + + while (sectors) { + int s = sectors; + struct md_rdev *rdev; + sector_t addr; + int ok; + + if (s > (PAGE_SIZE>>9)) + s = PAGE_SIZE >> 9; + + rdev = conf->mirrors[dr].rdev; + addr = r10_bio->devs[0].addr + sect, + ok = sync_page_io(rdev, + addr, + s << 9, + pages[idx], + REQ_OP_READ, false); + if (ok) { + rdev = conf->mirrors[dw].rdev; + addr = r10_bio->devs[1].addr + sect; + ok = sync_page_io(rdev, + addr, + s << 9, + pages[idx], + REQ_OP_WRITE, false); + if (!ok) { + set_bit(WriteErrorSeen, &rdev->flags); + if (!test_and_set_bit(WantReplacement, + &rdev->flags)) + set_bit(MD_RECOVERY_NEEDED, + &rdev->mddev->recovery); + } + } + if (!ok) { + /* We don't worry if we cannot set a bad block - + * it really is bad so there is no loss in not + * recording it yet + */ + rdev_set_badblocks(rdev, addr, s, 0); + + if (rdev != conf->mirrors[dw].rdev) { + /* need bad block on destination too */ + struct md_rdev *rdev2 = conf->mirrors[dw].rdev; + addr = r10_bio->devs[1].addr + sect; + ok = rdev_set_badblocks(rdev2, addr, s, 0); + if (!ok) { + /* just abort the recovery */ + pr_notice("md/raid10:%s: recovery aborted due to read error\n", + mdname(mddev)); + + conf->mirrors[dw].recovery_disabled + = mddev->recovery_disabled; + set_bit(MD_RECOVERY_INTR, + &mddev->recovery); + break; + } + } + } + + sectors -= s; + sect += s; + idx++; + } +} + +static void recovery_request_write(struct mddev *mddev, struct r10bio *r10_bio) +{ + struct r10conf *conf = mddev->private; + int d; + struct bio *wbio = r10_bio->devs[1].bio; + struct bio *wbio2 = r10_bio->devs[1].repl_bio; + + /* Need to test wbio2->bi_end_io before we call + * submit_bio_noacct as if the former is NULL, + * the latter is free to free wbio2. + */ + if (wbio2 && !wbio2->bi_end_io) + wbio2 = NULL; + + if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) { + fix_recovery_read_error(r10_bio); + if (wbio->bi_end_io) + end_sync_request(r10_bio); + if (wbio2) + end_sync_request(r10_bio); + return; + } + + /* + * share the pages with the first bio + * and submit the write request + */ + d = r10_bio->devs[1].devnum; + if (wbio->bi_end_io) { + atomic_inc(&conf->mirrors[d].rdev->nr_pending); + md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio)); + submit_bio_noacct(wbio); + } + if (wbio2) { + atomic_inc(&conf->mirrors[d].replacement->nr_pending); + md_sync_acct(conf->mirrors[d].replacement->bdev, + bio_sectors(wbio2)); + submit_bio_noacct(wbio2); + } +} + +/* + * Used by fix_read_error() to decay the per rdev read_errors. + * We halve the read error count for every hour that has elapsed + * since the last recorded read error. + * + */ +static void check_decay_read_errors(struct mddev *mddev, struct md_rdev *rdev) +{ + long cur_time_mon; + unsigned long hours_since_last; + unsigned int read_errors = atomic_read(&rdev->read_errors); + + cur_time_mon = ktime_get_seconds(); + + if (rdev->last_read_error == 0) { + /* first time we've seen a read error */ + rdev->last_read_error = cur_time_mon; + return; + } + + hours_since_last = (long)(cur_time_mon - + rdev->last_read_error) / 3600; + + rdev->last_read_error = cur_time_mon; + + /* + * if hours_since_last is > the number of bits in read_errors + * just set read errors to 0. We do this to avoid + * overflowing the shift of read_errors by hours_since_last. + */ + if (hours_since_last >= 8 * sizeof(read_errors)) + atomic_set(&rdev->read_errors, 0); + else + atomic_set(&rdev->read_errors, read_errors >> hours_since_last); +} + +static int r10_sync_page_io(struct md_rdev *rdev, sector_t sector, + int sectors, struct page *page, enum req_op op) +{ + sector_t first_bad; + int bad_sectors; + + if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors) + && (op == REQ_OP_READ || test_bit(WriteErrorSeen, &rdev->flags))) + return -1; + if (sync_page_io(rdev, sector, sectors << 9, page, op, false)) + /* success */ + return 1; + if (op == 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; +} + +/* + * 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 r10conf *conf, struct mddev *mddev, struct r10bio *r10_bio) +{ + int sect = 0; /* Offset from r10_bio->sector */ + int sectors = r10_bio->sectors, slot = r10_bio->read_slot; + struct md_rdev *rdev; + int max_read_errors = atomic_read(&mddev->max_corr_read_errors); + int d = r10_bio->devs[slot].devnum; + + /* still own a reference to this rdev, so it cannot + * have been cleared recently. + */ + rdev = conf->mirrors[d].rdev; + + if (test_bit(Faulty, &rdev->flags)) + /* drive has already been failed, just ignore any + more fix_read_error() attempts */ + return; + + check_decay_read_errors(mddev, rdev); + atomic_inc(&rdev->read_errors); + if (atomic_read(&rdev->read_errors) > max_read_errors) { + pr_notice("md/raid10:%s: %pg: Raid device exceeded read_error threshold [cur %d:max %d]\n", + mdname(mddev), rdev->bdev, + atomic_read(&rdev->read_errors), max_read_errors); + pr_notice("md/raid10:%s: %pg: Failing raid device\n", + mdname(mddev), rdev->bdev); + md_error(mddev, rdev); + r10_bio->devs[slot].bio = IO_BLOCKED; + return; + } + + while(sectors) { + int s = sectors; + int sl = slot; + int success = 0; + int start; + + if (s > (PAGE_SIZE>>9)) + s = PAGE_SIZE >> 9; + + rcu_read_lock(); + do { + sector_t first_bad; + int bad_sectors; + + d = r10_bio->devs[sl].devnum; + rdev = rcu_dereference(conf->mirrors[d].rdev); + if (rdev && + test_bit(In_sync, &rdev->flags) && + !test_bit(Faulty, &rdev->flags) && + is_badblock(rdev, r10_bio->devs[sl].addr + sect, s, + &first_bad, &bad_sectors) == 0) { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + success = sync_page_io(rdev, + r10_bio->devs[sl].addr + + sect, + s<<9, + conf->tmppage, + REQ_OP_READ, false); + rdev_dec_pending(rdev, mddev); + rcu_read_lock(); + if (success) + break; + } + sl++; + if (sl == conf->copies) + sl = 0; + } while (sl != slot); + rcu_read_unlock(); + + if (!success) { + /* Cannot read from anywhere, just mark the block + * as bad on the first device to discourage future + * reads. + */ + int dn = r10_bio->devs[slot].devnum; + rdev = conf->mirrors[dn].rdev; + + if (!rdev_set_badblocks( + rdev, + r10_bio->devs[slot].addr + + sect, + s, 0)) { + md_error(mddev, rdev); + r10_bio->devs[slot].bio + = IO_BLOCKED; + } + break; + } + + start = sl; + /* write it back and re-read */ + rcu_read_lock(); + while (sl != slot) { + if (sl==0) + sl = conf->copies; + sl--; + d = r10_bio->devs[sl].devnum; + rdev = rcu_dereference(conf->mirrors[d].rdev); + if (!rdev || + test_bit(Faulty, &rdev->flags) || + !test_bit(In_sync, &rdev->flags)) + continue; + + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + if (r10_sync_page_io(rdev, + r10_bio->devs[sl].addr + + sect, + s, conf->tmppage, REQ_OP_WRITE) + == 0) { + /* Well, this device is dead */ + pr_notice("md/raid10:%s: read correction write failed (%d sectors at %llu on %pg)\n", + mdname(mddev), s, + (unsigned long long)( + sect + + choose_data_offset(r10_bio, + rdev)), + rdev->bdev); + pr_notice("md/raid10:%s: %pg: failing drive\n", + mdname(mddev), + rdev->bdev); + } + rdev_dec_pending(rdev, mddev); + rcu_read_lock(); + } + sl = start; + while (sl != slot) { + if (sl==0) + sl = conf->copies; + sl--; + d = r10_bio->devs[sl].devnum; + rdev = rcu_dereference(conf->mirrors[d].rdev); + if (!rdev || + test_bit(Faulty, &rdev->flags) || + !test_bit(In_sync, &rdev->flags)) + continue; + + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + switch (r10_sync_page_io(rdev, + r10_bio->devs[sl].addr + + sect, + s, conf->tmppage, REQ_OP_READ)) { + case 0: + /* Well, this device is dead */ + pr_notice("md/raid10:%s: unable to read back corrected sectors (%d sectors at %llu on %pg)\n", + mdname(mddev), s, + (unsigned long long)( + sect + + choose_data_offset(r10_bio, rdev)), + rdev->bdev); + pr_notice("md/raid10:%s: %pg: failing drive\n", + mdname(mddev), + rdev->bdev); + break; + case 1: + pr_info("md/raid10:%s: read error corrected (%d sectors at %llu on %pg)\n", + mdname(mddev), s, + (unsigned long long)( + sect + + choose_data_offset(r10_bio, rdev)), + rdev->bdev); + atomic_add(s, &rdev->corrected_errors); + } + + rdev_dec_pending(rdev, mddev); + rcu_read_lock(); + } + rcu_read_unlock(); + + sectors -= s; + sect += s; + } +} + +static int narrow_write_error(struct r10bio *r10_bio, int i) +{ + struct bio *bio = r10_bio->master_bio; + struct mddev *mddev = r10_bio->mddev; + struct r10conf *conf = mddev->private; + struct md_rdev *rdev = conf->mirrors[r10_bio->devs[i].devnum].rdev; + /* bio has the data to be written to slot '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. + * + * We currently own a reference to the rdev. + */ + + int block_sectors; + sector_t sector; + int sectors; + int sect_to_write = r10_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 = r10_bio->sector; + sectors = ((r10_bio->sector + block_sectors) + & ~(sector_t)(block_sectors - 1)) + - sector; + + while (sect_to_write) { + struct bio *wbio; + sector_t wsector; + if (sectors > sect_to_write) + sectors = sect_to_write; + /* Write at 'sector' for 'sectors' */ + wbio = bio_alloc_clone(rdev->bdev, bio, GFP_NOIO, + &mddev->bio_set); + bio_trim(wbio, sector - bio->bi_iter.bi_sector, sectors); + wsector = r10_bio->devs[i].addr + (sector - r10_bio->sector); + wbio->bi_iter.bi_sector = wsector + + choose_data_offset(r10_bio, rdev); + wbio->bi_opf = REQ_OP_WRITE; + + if (submit_bio_wait(wbio) < 0) + /* Failure! */ + ok = rdev_set_badblocks(rdev, wsector, + sectors, 0) + && ok; + + bio_put(wbio); + sect_to_write -= sectors; + sector += sectors; + sectors = block_sectors; + } + return ok; +} + +static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio) +{ + int slot = r10_bio->read_slot; + struct bio *bio; + struct r10conf *conf = mddev->private; + struct md_rdev *rdev = r10_bio->devs[slot].rdev; + + /* 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 = r10_bio->devs[slot].bio; + bio_put(bio); + r10_bio->devs[slot].bio = NULL; + + if (mddev->ro) + r10_bio->devs[slot].bio = IO_BLOCKED; + else if (!test_bit(FailFast, &rdev->flags)) { + freeze_array(conf, 1); + fix_read_error(conf, mddev, r10_bio); + unfreeze_array(conf); + } else + md_error(mddev, rdev); + + rdev_dec_pending(rdev, mddev); + r10_bio->state = 0; + raid10_read_request(mddev, r10_bio->master_bio, r10_bio, false); + /* + * allow_barrier after re-submit to ensure no sync io + * can be issued while regular io pending. + */ + allow_barrier(conf); +} + +static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio) +{ + /* Some sort of write request has finished and it + * succeeded in writing where we thought there was a + * bad block. So forget the bad block. + * Or possibly if failed and we need to record + * a bad block. + */ + int m; + struct md_rdev *rdev; + + if (test_bit(R10BIO_IsSync, &r10_bio->state) || + test_bit(R10BIO_IsRecover, &r10_bio->state)) { + for (m = 0; m < conf->copies; m++) { + int dev = r10_bio->devs[m].devnum; + rdev = conf->mirrors[dev].rdev; + if (r10_bio->devs[m].bio == NULL || + r10_bio->devs[m].bio->bi_end_io == NULL) + continue; + if (!r10_bio->devs[m].bio->bi_status) { + rdev_clear_badblocks( + rdev, + r10_bio->devs[m].addr, + r10_bio->sectors, 0); + } else { + if (!rdev_set_badblocks( + rdev, + r10_bio->devs[m].addr, + r10_bio->sectors, 0)) + md_error(conf->mddev, rdev); + } + rdev = conf->mirrors[dev].replacement; + if (r10_bio->devs[m].repl_bio == NULL || + r10_bio->devs[m].repl_bio->bi_end_io == NULL) + continue; + + if (!r10_bio->devs[m].repl_bio->bi_status) { + rdev_clear_badblocks( + rdev, + r10_bio->devs[m].addr, + r10_bio->sectors, 0); + } else { + if (!rdev_set_badblocks( + rdev, + r10_bio->devs[m].addr, + r10_bio->sectors, 0)) + md_error(conf->mddev, rdev); + } + } + put_buf(r10_bio); + } else { + bool fail = false; + for (m = 0; m < conf->copies; m++) { + int dev = r10_bio->devs[m].devnum; + struct bio *bio = r10_bio->devs[m].bio; + rdev = conf->mirrors[dev].rdev; + if (bio == IO_MADE_GOOD) { + rdev_clear_badblocks( + rdev, + r10_bio->devs[m].addr, + r10_bio->sectors, 0); + rdev_dec_pending(rdev, conf->mddev); + } else if (bio != NULL && bio->bi_status) { + fail = true; + if (!narrow_write_error(r10_bio, m)) { + md_error(conf->mddev, rdev); + set_bit(R10BIO_Degraded, + &r10_bio->state); + } + rdev_dec_pending(rdev, conf->mddev); + } + bio = r10_bio->devs[m].repl_bio; + rdev = conf->mirrors[dev].replacement; + if (rdev && bio == IO_MADE_GOOD) { + rdev_clear_badblocks( + rdev, + r10_bio->devs[m].addr, + r10_bio->sectors, 0); + rdev_dec_pending(rdev, conf->mddev); + } + } + if (fail) { + spin_lock_irq(&conf->device_lock); + list_add(&r10_bio->retry_list, &conf->bio_end_io_list); + conf->nr_queued++; + spin_unlock_irq(&conf->device_lock); + /* + * In case freeze_array() is waiting for condition + * nr_pending == nr_queued + extra to be true. + */ + wake_up(&conf->wait_barrier); + md_wakeup_thread(conf->mddev->thread); + } else { + if (test_bit(R10BIO_WriteError, + &r10_bio->state)) + close_write(r10_bio); + raid_end_bio_io(r10_bio); + } + } +} + +static void raid10d(struct md_thread *thread) +{ + struct mddev *mddev = thread->mddev; + struct r10bio *r10_bio; + unsigned long flags; + struct r10conf *conf = mddev->private; + struct list_head *head = &conf->retry_list; + struct blk_plug plug; + + 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)) { + while (!list_empty(&conf->bio_end_io_list)) { + list_move(conf->bio_end_io_list.prev, &tmp); + conf->nr_queued--; + } + } + spin_unlock_irqrestore(&conf->device_lock, flags); + while (!list_empty(&tmp)) { + r10_bio = list_first_entry(&tmp, struct r10bio, + retry_list); + list_del(&r10_bio->retry_list); + if (mddev->degraded) + set_bit(R10BIO_Degraded, &r10_bio->state); + + if (test_bit(R10BIO_WriteError, + &r10_bio->state)) + close_write(r10_bio); + raid_end_bio_io(r10_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; + } + r10_bio = list_entry(head->prev, struct r10bio, retry_list); + list_del(head->prev); + conf->nr_queued--; + spin_unlock_irqrestore(&conf->device_lock, flags); + + mddev = r10_bio->mddev; + conf = mddev->private; + if (test_bit(R10BIO_MadeGood, &r10_bio->state) || + test_bit(R10BIO_WriteError, &r10_bio->state)) + handle_write_completed(conf, r10_bio); + else if (test_bit(R10BIO_IsReshape, &r10_bio->state)) + reshape_request_write(mddev, r10_bio); + else if (test_bit(R10BIO_IsSync, &r10_bio->state)) + sync_request_write(mddev, r10_bio); + else if (test_bit(R10BIO_IsRecover, &r10_bio->state)) + recovery_request_write(mddev, r10_bio); + else if (test_bit(R10BIO_ReadError, &r10_bio->state)) + handle_read_error(mddev, r10_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 r10conf *conf) +{ + int ret, buffs, i; + + buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; + BUG_ON(mempool_initialized(&conf->r10buf_pool)); + conf->have_replacement = 0; + for (i = 0; i < conf->geo.raid_disks; i++) + if (conf->mirrors[i].replacement) + conf->have_replacement = 1; + ret = mempool_init(&conf->r10buf_pool, buffs, + r10buf_pool_alloc, r10buf_pool_free, conf); + if (ret) + return ret; + conf->next_resync = 0; + return 0; +} + +static struct r10bio *raid10_alloc_init_r10buf(struct r10conf *conf) +{ + struct r10bio *r10bio = mempool_alloc(&conf->r10buf_pool, GFP_NOIO); + struct rsync_pages *rp; + struct bio *bio; + int nalloc; + int i; + + if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery) || + test_bit(MD_RECOVERY_RESHAPE, &conf->mddev->recovery)) + nalloc = conf->copies; /* resync */ + else + nalloc = 2; /* recovery */ + + for (i = 0; i < nalloc; i++) { + bio = r10bio->devs[i].bio; + rp = bio->bi_private; + bio_reset(bio, NULL, 0); + bio->bi_private = rp; + bio = r10bio->devs[i].repl_bio; + if (bio) { + rp = bio->bi_private; + bio_reset(bio, NULL, 0); + bio->bi_private = rp; + } + } + return r10bio; +} + +/* + * Set cluster_sync_high since we need other nodes to add the + * range [cluster_sync_low, cluster_sync_high] to suspend list. + */ +static void raid10_set_cluster_sync_high(struct r10conf *conf) +{ + sector_t window_size; + int extra_chunk, chunks; + + /* + * First, here we define "stripe" as a unit which across + * all member devices one time, so we get chunks by use + * raid_disks / near_copies. Otherwise, if near_copies is + * close to raid_disks, then resync window could increases + * linearly with the increase of raid_disks, which means + * we will suspend a really large IO window while it is not + * necessary. If raid_disks is not divisible by near_copies, + * an extra chunk is needed to ensure the whole "stripe" is + * covered. + */ + + chunks = conf->geo.raid_disks / conf->geo.near_copies; + if (conf->geo.raid_disks % conf->geo.near_copies == 0) + extra_chunk = 0; + else + extra_chunk = 1; + window_size = (chunks + extra_chunk) * conf->mddev->chunk_sectors; + + /* + * At least use a 32M window to align with raid1's resync window + */ + window_size = (CLUSTER_RESYNC_WINDOW_SECTORS > window_size) ? + CLUSTER_RESYNC_WINDOW_SECTORS : window_size; + + conf->cluster_sync_high = conf->cluster_sync_low + window_size; +} + +/* + * 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. + * + * Resync and recovery are handled very differently. + * We differentiate by looking at MD_RECOVERY_SYNC in mddev->recovery. + * + * For resync, we iterate over virtual addresses, read all copies, + * and update if there are differences. If only one copy is live, + * skip it. + * For recovery, we iterate over physical addresses, read a good + * value for each non-in_sync drive, and over-write. + * + * So, for recovery we may have several outstanding complex requests for a + * given address, one for each out-of-sync device. We model this by allocating + * a number of r10_bio structures, one for each out-of-sync device. + * As we setup these structures, we collect all bio's together into a list + * which we then process collectively to add pages, and then process again + * to pass to submit_bio_noacct. + * + * The r10_bio structures are linked using a borrowed master_bio pointer. + * This link is counted in ->remaining. When the r10_bio that points to NULL + * has its remaining count decremented to 0, the whole complex operation + * is complete. + * + */ + +static sector_t raid10_sync_request(struct mddev *mddev, sector_t sector_nr, + int *skipped) +{ + struct r10conf *conf = mddev->private; + struct r10bio *r10_bio; + struct bio *biolist = NULL, *bio; + sector_t max_sector, nr_sectors; + int i; + int max_sync; + sector_t sync_blocks; + sector_t sectors_skipped = 0; + int chunks_skipped = 0; + sector_t chunk_mask = conf->geo.chunk_mask; + int page_idx = 0; + int error_disk = -1; + + /* + * Allow skipping a full rebuild for incremental assembly + * of a clean array, like RAID1 does. + */ + if (mddev->bitmap == NULL && + mddev->recovery_cp == MaxSector && + mddev->reshape_position == MaxSector && + !test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && + !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && + !test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && + conf->fullsync == 0) { + *skipped = 1; + return mddev->dev_sectors - sector_nr; + } + + if (!mempool_initialized(&conf->r10buf_pool)) + if (init_resync(conf)) + return 0; + + skipped: + max_sector = mddev->dev_sectors; + if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) || + test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + max_sector = mddev->resync_max_sectors; + if (sector_nr >= max_sector) { + conf->cluster_sync_low = 0; + conf->cluster_sync_high = 0; + + /* If we aborted, we need to abort the + * sync on the 'current' bitmap chucks (there can + * be several when recovering multiple devices). + * as we may have started syncing it but not finished. + * We can find the current address in + * mddev->curr_resync, but for recovery, + * we need to convert that to several + * virtual addresses. + */ + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) { + end_reshape(conf); + close_sync(conf); + return 0; + } + + if (mddev->curr_resync < max_sector) { /* aborted */ + if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) + md_bitmap_end_sync(mddev->bitmap, mddev->curr_resync, + &sync_blocks, 1); + else for (i = 0; i < conf->geo.raid_disks; i++) { + sector_t sect = + raid10_find_virt(conf, mddev->curr_resync, i); + md_bitmap_end_sync(mddev->bitmap, sect, + &sync_blocks, 1); + } + } else { + /* completed sync */ + if ((!mddev->bitmap || conf->fullsync) + && conf->have_replacement + && test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + /* Completed a full sync so the replacements + * are now fully recovered. + */ + rcu_read_lock(); + for (i = 0; i < conf->geo.raid_disks; i++) { + struct md_rdev *rdev = + rcu_dereference(conf->mirrors[i].replacement); + if (rdev) + rdev->recovery_offset = MaxSector; + } + rcu_read_unlock(); + } + conf->fullsync = 0; + } + md_bitmap_close_sync(mddev->bitmap); + close_sync(conf); + *skipped = 1; + return sectors_skipped; + } + + if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) + return reshape_request(mddev, sector_nr, skipped); + + if (chunks_skipped >= conf->geo.raid_disks) { + pr_err("md/raid10:%s: %s fails\n", mdname(mddev), + test_bit(MD_RECOVERY_SYNC, &mddev->recovery) ? "resync" : "recovery"); + if (error_disk >= 0 && + !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + /* + * recovery fails, set mirrors.recovery_disabled, + * device shouldn't be added to there. + */ + conf->mirrors[error_disk].recovery_disabled = + mddev->recovery_disabled; + return 0; + } + /* + * if there has been nothing to do on any drive, + * then there is nothing to do at all. + */ + *skipped = 1; + return (max_sector - sector_nr) + sectors_skipped; + } + + if (max_sector > mddev->resync_max) + max_sector = mddev->resync_max; /* Don't do IO beyond here */ + + /* make sure whole request will fit in a chunk - if chunks + * are meaningful + */ + if (conf->geo.near_copies < conf->geo.raid_disks && + max_sector > (sector_nr | chunk_mask)) + max_sector = (sector_nr | chunk_mask) + 1; + + /* + * If there is non-resync activity waiting for a turn, then let it + * though before starting on this new sync request. + */ + if (conf->nr_waiting) + schedule_timeout_uninterruptible(1); + + /* Again, very different code for resync and recovery. + * Both must result in an r10bio with a list of bios that + * have bi_end_io, bi_sector, bi_bdev set, + * and bi_private set to the r10bio. + * For recovery, we may actually create several r10bios + * with 2 bios in each, that correspond to the bios in the main one. + * In this case, the subordinate r10bios link back through a + * borrowed master_bio pointer, and the counter in the master + * includes a ref from each subordinate. + */ + /* First, we decide what to do and set ->bi_end_io + * To end_sync_read if we want to read, and + * end_sync_write if we will want to write. + */ + + max_sync = RESYNC_PAGES << (PAGE_SHIFT-9); + if (!test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + /* recovery... the complicated one */ + int j; + r10_bio = NULL; + + for (i = 0 ; i < conf->geo.raid_disks; i++) { + int still_degraded; + struct r10bio *rb2; + sector_t sect; + int must_sync; + int any_working; + struct raid10_info *mirror = &conf->mirrors[i]; + struct md_rdev *mrdev, *mreplace; + + rcu_read_lock(); + mrdev = rcu_dereference(mirror->rdev); + mreplace = rcu_dereference(mirror->replacement); + + if (mrdev && (test_bit(Faulty, &mrdev->flags) || + test_bit(In_sync, &mrdev->flags))) + mrdev = NULL; + if (mreplace && test_bit(Faulty, &mreplace->flags)) + mreplace = NULL; + + if (!mrdev && !mreplace) { + rcu_read_unlock(); + continue; + } + + still_degraded = 0; + /* want to reconstruct this device */ + rb2 = r10_bio; + sect = raid10_find_virt(conf, sector_nr, i); + if (sect >= mddev->resync_max_sectors) { + /* last stripe is not complete - don't + * try to recover this sector. + */ + rcu_read_unlock(); + continue; + } + /* Unless we are doing a full sync, or a replacement + * we only need to recover the block if it is set in + * the bitmap + */ + must_sync = md_bitmap_start_sync(mddev->bitmap, sect, + &sync_blocks, 1); + if (sync_blocks < max_sync) + max_sync = sync_blocks; + if (!must_sync && + mreplace == NULL && + !conf->fullsync) { + /* yep, skip the sync_blocks here, but don't assume + * that there will never be anything to do here + */ + chunks_skipped = -1; + rcu_read_unlock(); + continue; + } + if (mrdev) + atomic_inc(&mrdev->nr_pending); + if (mreplace) + atomic_inc(&mreplace->nr_pending); + rcu_read_unlock(); + + r10_bio = raid10_alloc_init_r10buf(conf); + r10_bio->state = 0; + raise_barrier(conf, rb2 != NULL); + atomic_set(&r10_bio->remaining, 0); + + r10_bio->master_bio = (struct bio*)rb2; + if (rb2) + atomic_inc(&rb2->remaining); + r10_bio->mddev = mddev; + set_bit(R10BIO_IsRecover, &r10_bio->state); + r10_bio->sector = sect; + + raid10_find_phys(conf, r10_bio); + + /* Need to check if the array will still be + * degraded + */ + rcu_read_lock(); + for (j = 0; j < conf->geo.raid_disks; j++) { + struct md_rdev *rdev = rcu_dereference( + conf->mirrors[j].rdev); + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { + still_degraded = 1; + break; + } + } + + must_sync = md_bitmap_start_sync(mddev->bitmap, sect, + &sync_blocks, still_degraded); + + any_working = 0; + for (j=0; j<conf->copies;j++) { + int k; + int d = r10_bio->devs[j].devnum; + sector_t from_addr, to_addr; + struct md_rdev *rdev = + rcu_dereference(conf->mirrors[d].rdev); + sector_t sector, first_bad; + int bad_sectors; + if (!rdev || + !test_bit(In_sync, &rdev->flags)) + continue; + /* This is where we read from */ + any_working = 1; + sector = r10_bio->devs[j].addr; + + if (is_badblock(rdev, sector, max_sync, + &first_bad, &bad_sectors)) { + if (first_bad > sector) + max_sync = first_bad - sector; + else { + bad_sectors -= (sector + - first_bad); + if (max_sync > bad_sectors) + max_sync = bad_sectors; + continue; + } + } + bio = r10_bio->devs[0].bio; + bio->bi_next = biolist; + biolist = bio; + bio->bi_end_io = end_sync_read; + bio->bi_opf = REQ_OP_READ; + if (test_bit(FailFast, &rdev->flags)) + bio->bi_opf |= MD_FAILFAST; + from_addr = r10_bio->devs[j].addr; + bio->bi_iter.bi_sector = from_addr + + rdev->data_offset; + bio_set_dev(bio, rdev->bdev); + atomic_inc(&rdev->nr_pending); + /* and we write to 'i' (if not in_sync) */ + + for (k=0; k<conf->copies; k++) + if (r10_bio->devs[k].devnum == i) + break; + BUG_ON(k == conf->copies); + to_addr = r10_bio->devs[k].addr; + r10_bio->devs[0].devnum = d; + r10_bio->devs[0].addr = from_addr; + r10_bio->devs[1].devnum = i; + r10_bio->devs[1].addr = to_addr; + + if (mrdev) { + bio = r10_bio->devs[1].bio; + bio->bi_next = biolist; + biolist = bio; + bio->bi_end_io = end_sync_write; + bio->bi_opf = REQ_OP_WRITE; + bio->bi_iter.bi_sector = to_addr + + mrdev->data_offset; + bio_set_dev(bio, mrdev->bdev); + atomic_inc(&r10_bio->remaining); + } else + r10_bio->devs[1].bio->bi_end_io = NULL; + + /* and maybe write to replacement */ + bio = r10_bio->devs[1].repl_bio; + if (bio) + bio->bi_end_io = NULL; + /* Note: if replace is not NULL, then bio + * cannot be NULL as r10buf_pool_alloc will + * have allocated it. + */ + if (!mreplace) + break; + bio->bi_next = biolist; + biolist = bio; + bio->bi_end_io = end_sync_write; + bio->bi_opf = REQ_OP_WRITE; + bio->bi_iter.bi_sector = to_addr + + mreplace->data_offset; + bio_set_dev(bio, mreplace->bdev); + atomic_inc(&r10_bio->remaining); + break; + } + rcu_read_unlock(); + if (j == conf->copies) { + /* Cannot recover, so abort the recovery or + * record a bad block */ + if (any_working) { + /* problem is that there are bad blocks + * on other device(s) + */ + int k; + for (k = 0; k < conf->copies; k++) + if (r10_bio->devs[k].devnum == i) + break; + if (mrdev && !test_bit(In_sync, + &mrdev->flags) + && !rdev_set_badblocks( + mrdev, + r10_bio->devs[k].addr, + max_sync, 0)) + any_working = 0; + if (mreplace && + !rdev_set_badblocks( + mreplace, + r10_bio->devs[k].addr, + max_sync, 0)) + any_working = 0; + } + if (!any_working) { + if (!test_and_set_bit(MD_RECOVERY_INTR, + &mddev->recovery)) + pr_warn("md/raid10:%s: insufficient working devices for recovery.\n", + mdname(mddev)); + mirror->recovery_disabled + = mddev->recovery_disabled; + } else { + error_disk = i; + } + put_buf(r10_bio); + if (rb2) + atomic_dec(&rb2->remaining); + r10_bio = rb2; + if (mrdev) + rdev_dec_pending(mrdev, mddev); + if (mreplace) + rdev_dec_pending(mreplace, mddev); + break; + } + if (mrdev) + rdev_dec_pending(mrdev, mddev); + if (mreplace) + rdev_dec_pending(mreplace, mddev); + if (r10_bio->devs[0].bio->bi_opf & MD_FAILFAST) { + /* Only want this if there is elsewhere to + * read from. 'j' is currently the first + * readable copy. + */ + int targets = 1; + for (; j < conf->copies; j++) { + int d = r10_bio->devs[j].devnum; + if (conf->mirrors[d].rdev && + test_bit(In_sync, + &conf->mirrors[d].rdev->flags)) + targets++; + } + if (targets == 1) + r10_bio->devs[0].bio->bi_opf + &= ~MD_FAILFAST; + } + } + if (biolist == NULL) { + while (r10_bio) { + struct r10bio *rb2 = r10_bio; + r10_bio = (struct r10bio*) rb2->master_bio; + rb2->master_bio = NULL; + put_buf(rb2); + } + goto giveup; + } + } else { + /* resync. Schedule a read for every block at this virt offset */ + int count = 0; + + /* + * Since curr_resync_completed could probably not update in + * time, and we will set cluster_sync_low based on it. + * Let's check against "sector_nr + 2 * RESYNC_SECTORS" for + * safety reason, which ensures curr_resync_completed is + * updated in bitmap_cond_end_sync. + */ + md_bitmap_cond_end_sync(mddev->bitmap, sector_nr, + mddev_is_clustered(mddev) && + (sector_nr + 2 * RESYNC_SECTORS > conf->cluster_sync_high)); + + if (!md_bitmap_start_sync(mddev->bitmap, sector_nr, + &sync_blocks, mddev->degraded) && + !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, + &mddev->recovery)) { + /* We can skip this block */ + *skipped = 1; + return sync_blocks + sectors_skipped; + } + if (sync_blocks < max_sync) + max_sync = sync_blocks; + r10_bio = raid10_alloc_init_r10buf(conf); + r10_bio->state = 0; + + r10_bio->mddev = mddev; + atomic_set(&r10_bio->remaining, 0); + raise_barrier(conf, 0); + conf->next_resync = sector_nr; + + r10_bio->master_bio = NULL; + r10_bio->sector = sector_nr; + set_bit(R10BIO_IsSync, &r10_bio->state); + raid10_find_phys(conf, r10_bio); + r10_bio->sectors = (sector_nr | chunk_mask) - sector_nr + 1; + + for (i = 0; i < conf->copies; i++) { + int d = r10_bio->devs[i].devnum; + sector_t first_bad, sector; + int bad_sectors; + struct md_rdev *rdev; + + if (r10_bio->devs[i].repl_bio) + r10_bio->devs[i].repl_bio->bi_end_io = NULL; + + bio = r10_bio->devs[i].bio; + bio->bi_status = BLK_STS_IOERR; + rcu_read_lock(); + rdev = rcu_dereference(conf->mirrors[d].rdev); + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { + rcu_read_unlock(); + continue; + } + sector = r10_bio->devs[i].addr; + if (is_badblock(rdev, sector, max_sync, + &first_bad, &bad_sectors)) { + if (first_bad > sector) + max_sync = first_bad - sector; + else { + bad_sectors -= (sector - first_bad); + if (max_sync > bad_sectors) + max_sync = bad_sectors; + rcu_read_unlock(); + continue; + } + } + atomic_inc(&rdev->nr_pending); + atomic_inc(&r10_bio->remaining); + bio->bi_next = biolist; + biolist = bio; + bio->bi_end_io = end_sync_read; + bio->bi_opf = REQ_OP_READ; + if (test_bit(FailFast, &rdev->flags)) + bio->bi_opf |= MD_FAILFAST; + bio->bi_iter.bi_sector = sector + rdev->data_offset; + bio_set_dev(bio, rdev->bdev); + count++; + + rdev = rcu_dereference(conf->mirrors[d].replacement); + if (rdev == NULL || test_bit(Faulty, &rdev->flags)) { + rcu_read_unlock(); + continue; + } + atomic_inc(&rdev->nr_pending); + + /* Need to set up for writing to the replacement */ + bio = r10_bio->devs[i].repl_bio; + bio->bi_status = BLK_STS_IOERR; + + sector = r10_bio->devs[i].addr; + bio->bi_next = biolist; + biolist = bio; + bio->bi_end_io = end_sync_write; + bio->bi_opf = REQ_OP_WRITE; + if (test_bit(FailFast, &rdev->flags)) + bio->bi_opf |= MD_FAILFAST; + bio->bi_iter.bi_sector = sector + rdev->data_offset; + bio_set_dev(bio, rdev->bdev); + count++; + rcu_read_unlock(); + } + + if (count < 2) { + for (i=0; i<conf->copies; i++) { + int d = r10_bio->devs[i].devnum; + if (r10_bio->devs[i].bio->bi_end_io) + rdev_dec_pending(conf->mirrors[d].rdev, + mddev); + if (r10_bio->devs[i].repl_bio && + r10_bio->devs[i].repl_bio->bi_end_io) + rdev_dec_pending( + conf->mirrors[d].replacement, + mddev); + } + put_buf(r10_bio); + biolist = NULL; + goto giveup; + } + } + + nr_sectors = 0; + if (sector_nr + max_sync < max_sector) + max_sector = sector_nr + max_sync; + 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; + for (bio= biolist ; bio ; bio=bio->bi_next) { + struct resync_pages *rp = get_resync_pages(bio); + page = resync_fetch_page(rp, page_idx); + if (WARN_ON(!bio_add_page(bio, page, len, 0))) { + bio->bi_status = BLK_STS_RESOURCE; + bio_endio(bio); + goto giveup; + } + } + nr_sectors += len>>9; + sector_nr += len>>9; + } while (++page_idx < RESYNC_PAGES); + r10_bio->sectors = nr_sectors; + + if (mddev_is_clustered(mddev) && + test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) { + /* It is resync not recovery */ + if (conf->cluster_sync_high < sector_nr + nr_sectors) { + conf->cluster_sync_low = mddev->curr_resync_completed; + raid10_set_cluster_sync_high(conf); + /* Send resync message */ + md_cluster_ops->resync_info_update(mddev, + conf->cluster_sync_low, + conf->cluster_sync_high); + } + } else if (mddev_is_clustered(mddev)) { + /* This is recovery not resync */ + sector_t sect_va1, sect_va2; + bool broadcast_msg = false; + + for (i = 0; i < conf->geo.raid_disks; i++) { + /* + * sector_nr is a device address for recovery, so we + * need translate it to array address before compare + * with cluster_sync_high. + */ + sect_va1 = raid10_find_virt(conf, sector_nr, i); + + if (conf->cluster_sync_high < sect_va1 + nr_sectors) { + broadcast_msg = true; + /* + * curr_resync_completed is similar as + * sector_nr, so make the translation too. + */ + sect_va2 = raid10_find_virt(conf, + mddev->curr_resync_completed, i); + + if (conf->cluster_sync_low == 0 || + conf->cluster_sync_low > sect_va2) + conf->cluster_sync_low = sect_va2; + } + } + if (broadcast_msg) { + raid10_set_cluster_sync_high(conf); + md_cluster_ops->resync_info_update(mddev, + conf->cluster_sync_low, + conf->cluster_sync_high); + } + } + + while (biolist) { + bio = biolist; + biolist = biolist->bi_next; + + bio->bi_next = NULL; + r10_bio = get_resync_r10bio(bio); + r10_bio->sectors = nr_sectors; + + if (bio->bi_end_io == end_sync_read) { + md_sync_acct_bio(bio, nr_sectors); + bio->bi_status = 0; + submit_bio_noacct(bio); + } + } + + if (sectors_skipped) + /* pretend they weren't skipped, it makes + * no important difference in this case + */ + md_done_sync(mddev, sectors_skipped, 1); + + return sectors_skipped + nr_sectors; + giveup: + /* There is nowhere to write, so all non-sync + * drives must be failed or in resync, all drives + * have a bad block, so try the next chunk... + */ + if (sector_nr + max_sync < max_sector) + max_sector = sector_nr + max_sync; + + sectors_skipped += (max_sector - sector_nr); + chunks_skipped ++; + sector_nr = max_sector; + goto skipped; +} + +static sector_t +raid10_size(struct mddev *mddev, sector_t sectors, int raid_disks) +{ + sector_t size; + struct r10conf *conf = mddev->private; + + if (!raid_disks) + raid_disks = min(conf->geo.raid_disks, + conf->prev.raid_disks); + if (!sectors) + sectors = conf->dev_sectors; + + size = sectors >> conf->geo.chunk_shift; + sector_div(size, conf->geo.far_copies); + size = size * raid_disks; + sector_div(size, conf->geo.near_copies); + + return size << conf->geo.chunk_shift; +} + +static void calc_sectors(struct r10conf *conf, sector_t size) +{ + /* Calculate the number of sectors-per-device that will + * actually be used, and set conf->dev_sectors and + * conf->stride + */ + + size = size >> conf->geo.chunk_shift; + sector_div(size, conf->geo.far_copies); + size = size * conf->geo.raid_disks; + sector_div(size, conf->geo.near_copies); + /* 'size' is now the number of chunks in the array */ + /* calculate "used chunks per device" */ + size = size * conf->copies; + + /* We need to round up when dividing by raid_disks to + * get the stride size. + */ + size = DIV_ROUND_UP_SECTOR_T(size, conf->geo.raid_disks); + + conf->dev_sectors = size << conf->geo.chunk_shift; + + if (conf->geo.far_offset) + conf->geo.stride = 1 << conf->geo.chunk_shift; + else { + sector_div(size, conf->geo.far_copies); + conf->geo.stride = size << conf->geo.chunk_shift; + } +} + +enum geo_type {geo_new, geo_old, geo_start}; +static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new) +{ + int nc, fc, fo; + int layout, chunk, disks; + switch (new) { + case geo_old: + layout = mddev->layout; + chunk = mddev->chunk_sectors; + disks = mddev->raid_disks - mddev->delta_disks; + break; + case geo_new: + layout = mddev->new_layout; + chunk = mddev->new_chunk_sectors; + disks = mddev->raid_disks; + break; + default: /* avoid 'may be unused' warnings */ + case geo_start: /* new when starting reshape - raid_disks not + * updated yet. */ + layout = mddev->new_layout; + chunk = mddev->new_chunk_sectors; + disks = mddev->raid_disks + mddev->delta_disks; + break; + } + if (layout >> 19) + return -1; + if (chunk < (PAGE_SIZE >> 9) || + !is_power_of_2(chunk)) + return -2; + nc = layout & 255; + fc = (layout >> 8) & 255; + fo = layout & (1<<16); + geo->raid_disks = disks; + geo->near_copies = nc; + geo->far_copies = fc; + geo->far_offset = fo; + switch (layout >> 17) { + case 0: /* original layout. simple but not always optimal */ + geo->far_set_size = disks; + break; + case 1: /* "improved" layout which was buggy. Hopefully no-one is + * actually using this, but leave code here just in case.*/ + geo->far_set_size = disks/fc; + WARN(geo->far_set_size < fc, + "This RAID10 layout does not provide data safety - please backup and create new array\n"); + break; + case 2: /* "improved" layout fixed to match documentation */ + geo->far_set_size = fc * nc; + break; + default: /* Not a valid layout */ + return -1; + } + geo->chunk_mask = chunk - 1; + geo->chunk_shift = ffz(~chunk); + return nc*fc; +} + +static void raid10_free_conf(struct r10conf *conf) +{ + if (!conf) + return; + + mempool_exit(&conf->r10bio_pool); + kfree(conf->mirrors); + kfree(conf->mirrors_old); + kfree(conf->mirrors_new); + safe_put_page(conf->tmppage); + bioset_exit(&conf->bio_split); + kfree(conf); +} + +static struct r10conf *setup_conf(struct mddev *mddev) +{ + struct r10conf *conf = NULL; + int err = -EINVAL; + struct geom geo; + int copies; + + copies = setup_geo(&geo, mddev, geo_new); + + if (copies == -2) { + pr_warn("md/raid10:%s: chunk size must be at least PAGE_SIZE(%ld) and be a power of 2.\n", + mdname(mddev), PAGE_SIZE); + goto out; + } + + if (copies < 2 || copies > mddev->raid_disks) { + pr_warn("md/raid10:%s: unsupported raid10 layout: 0x%8x\n", + mdname(mddev), mddev->new_layout); + goto out; + } + + err = -ENOMEM; + conf = kzalloc(sizeof(struct r10conf), GFP_KERNEL); + if (!conf) + goto out; + + /* FIXME calc properly */ + conf->mirrors = kcalloc(mddev->raid_disks + max(0, -mddev->delta_disks), + sizeof(struct raid10_info), + GFP_KERNEL); + if (!conf->mirrors) + goto out; + + conf->tmppage = alloc_page(GFP_KERNEL); + if (!conf->tmppage) + goto out; + + conf->geo = geo; + conf->copies = copies; + err = mempool_init(&conf->r10bio_pool, NR_RAID_BIOS, r10bio_pool_alloc, + rbio_pool_free, conf); + if (err) + goto out; + + err = bioset_init(&conf->bio_split, BIO_POOL_SIZE, 0, 0); + if (err) + goto out; + + calc_sectors(conf, mddev->dev_sectors); + if (mddev->reshape_position == MaxSector) { + conf->prev = conf->geo; + conf->reshape_progress = MaxSector; + } else { + if (setup_geo(&conf->prev, mddev, geo_old) != conf->copies) { + err = -EINVAL; + goto out; + } + conf->reshape_progress = mddev->reshape_position; + if (conf->prev.far_offset) + conf->prev.stride = 1 << conf->prev.chunk_shift; + else + /* far_copies must be 1 */ + conf->prev.stride = conf->dev_sectors; + } + conf->reshape_safe = conf->reshape_progress; + spin_lock_init(&conf->device_lock); + INIT_LIST_HEAD(&conf->retry_list); + INIT_LIST_HEAD(&conf->bio_end_io_list); + + seqlock_init(&conf->resync_lock); + init_waitqueue_head(&conf->wait_barrier); + atomic_set(&conf->nr_pending, 0); + + err = -ENOMEM; + rcu_assign_pointer(conf->thread, + md_register_thread(raid10d, mddev, "raid10")); + if (!conf->thread) + goto out; + + conf->mddev = mddev; + return conf; + + out: + raid10_free_conf(conf); + return ERR_PTR(err); +} + +static void raid10_set_io_opt(struct r10conf *conf) +{ + int raid_disks = conf->geo.raid_disks; + + if (!(conf->geo.raid_disks % conf->geo.near_copies)) + raid_disks /= conf->geo.near_copies; + blk_queue_io_opt(conf->mddev->queue, (conf->mddev->chunk_sectors << 9) * + raid_disks); +} + +static int raid10_run(struct mddev *mddev) +{ + struct r10conf *conf; + int i, disk_idx; + struct raid10_info *disk; + struct md_rdev *rdev; + sector_t size; + sector_t min_offset_diff = 0; + int first = 1; + + if (mddev_init_writes_pending(mddev) < 0) + return -ENOMEM; + + if (mddev->private == NULL) { + conf = setup_conf(mddev); + if (IS_ERR(conf)) + return PTR_ERR(conf); + mddev->private = conf; + } + conf = mddev->private; + if (!conf) + goto out; + + rcu_assign_pointer(mddev->thread, conf->thread); + rcu_assign_pointer(conf->thread, NULL); + + if (mddev_is_clustered(conf->mddev)) { + int fc, fo; + + fc = (mddev->layout >> 8) & 255; + fo = mddev->layout & (1<<16); + if (fc > 1 || fo > 0) { + pr_err("only near layout is supported by clustered" + " raid10\n"); + goto out_free_conf; + } + } + + if (mddev->queue) { + blk_queue_max_write_zeroes_sectors(mddev->queue, 0); + blk_queue_io_min(mddev->queue, mddev->chunk_sectors << 9); + raid10_set_io_opt(conf); + } + + rdev_for_each(rdev, mddev) { + long long diff; + + disk_idx = rdev->raid_disk; + if (disk_idx < 0) + continue; + if (disk_idx >= conf->geo.raid_disks && + disk_idx >= conf->prev.raid_disks) + continue; + disk = conf->mirrors + disk_idx; + + if (test_bit(Replacement, &rdev->flags)) { + if (disk->replacement) + goto out_free_conf; + disk->replacement = rdev; + } else { + if (disk->rdev) + goto out_free_conf; + disk->rdev = rdev; + } + diff = (rdev->new_data_offset - rdev->data_offset); + if (!mddev->reshape_backwards) + diff = -diff; + if (diff < 0) + diff = 0; + if (first || diff < min_offset_diff) + min_offset_diff = diff; + + if (mddev->gendisk) + disk_stack_limits(mddev->gendisk, rdev->bdev, + rdev->data_offset << 9); + + disk->head_position = 0; + first = 0; + } + + /* need to check that every block has at least one working mirror */ + if (!enough(conf, -1)) { + pr_err("md/raid10:%s: not enough operational mirrors.\n", + mdname(mddev)); + goto out_free_conf; + } + + if (conf->reshape_progress != MaxSector) { + /* must ensure that shape change is supported */ + if (conf->geo.far_copies != 1 && + conf->geo.far_offset == 0) + goto out_free_conf; + if (conf->prev.far_copies != 1 && + conf->prev.far_offset == 0) + goto out_free_conf; + } + + mddev->degraded = 0; + for (i = 0; + i < conf->geo.raid_disks + || i < conf->prev.raid_disks; + i++) { + + disk = conf->mirrors + i; + + if (!disk->rdev && disk->replacement) { + /* The replacement is all we have - use it */ + disk->rdev = disk->replacement; + disk->replacement = NULL; + clear_bit(Replacement, &disk->rdev->flags); + } + + if (!disk->rdev || + !test_bit(In_sync, &disk->rdev->flags)) { + disk->head_position = 0; + mddev->degraded++; + if (disk->rdev && + disk->rdev->saved_raid_disk < 0) + conf->fullsync = 1; + } + + if (disk->replacement && + !test_bit(In_sync, &disk->replacement->flags) && + disk->replacement->saved_raid_disk < 0) { + conf->fullsync = 1; + } + + disk->recovery_disabled = mddev->recovery_disabled - 1; + } + + if (mddev->recovery_cp != MaxSector) + pr_notice("md/raid10:%s: not clean -- starting background reconstruction\n", + mdname(mddev)); + pr_info("md/raid10:%s: active with %d out of %d devices\n", + mdname(mddev), conf->geo.raid_disks - mddev->degraded, + conf->geo.raid_disks); + /* + * Ok, everything is just fine now + */ + mddev->dev_sectors = conf->dev_sectors; + size = raid10_size(mddev, 0, 0); + md_set_array_sectors(mddev, size); + mddev->resync_max_sectors = size; + set_bit(MD_FAILFAST_SUPPORTED, &mddev->flags); + + if (md_integrity_register(mddev)) + goto out_free_conf; + + if (conf->reshape_progress != MaxSector) { + unsigned long before_length, after_length; + + before_length = ((1 << conf->prev.chunk_shift) * + conf->prev.far_copies); + after_length = ((1 << conf->geo.chunk_shift) * + conf->geo.far_copies); + + if (max(before_length, after_length) > min_offset_diff) { + /* This cannot work */ + pr_warn("md/raid10: offset difference not enough to continue reshape\n"); + goto out_free_conf; + } + conf->offset_diff = min_offset_diff; + + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); + set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); + rcu_assign_pointer(mddev->sync_thread, + md_register_thread(md_do_sync, mddev, "reshape")); + if (!mddev->sync_thread) + goto out_free_conf; + } + + return 0; + +out_free_conf: + md_unregister_thread(mddev, &mddev->thread); + raid10_free_conf(conf); + mddev->private = NULL; +out: + return -EIO; +} + +static void raid10_free(struct mddev *mddev, void *priv) +{ + raid10_free_conf(priv); +} + +static void raid10_quiesce(struct mddev *mddev, int quiesce) +{ + struct r10conf *conf = mddev->private; + + if (quiesce) + raise_barrier(conf, 0); + else + lower_barrier(conf); +} + +static int raid10_resize(struct mddev *mddev, sector_t sectors) +{ + /* Resize of 'far' arrays is not supported. + * For 'near' and 'offset' arrays we can set the + * number of sectors used to be an appropriate multiple + * of the chunk size. + * For 'offset', this is far_copies*chunksize. + * For 'near' the multiplier is the LCM of + * near_copies and raid_disks. + * So if far_copies > 1 && !far_offset, fail. + * Else find LCM(raid_disks, near_copy)*far_copies and + * multiply by chunk_size. Then round to this number. + * This is mostly done by raid10_size() + */ + struct r10conf *conf = mddev->private; + sector_t oldsize, size; + + if (mddev->reshape_position != MaxSector) + return -EBUSY; + + if (conf->geo.far_copies > 1 && !conf->geo.far_offset) + return -EINVAL; + + oldsize = raid10_size(mddev, 0, 0); + size = raid10_size(mddev, sectors, 0); + if (mddev->external_size && + mddev->array_sectors > size) + return -EINVAL; + if (mddev->bitmap) { + int ret = md_bitmap_resize(mddev->bitmap, size, 0, 0); + if (ret) + return ret; + } + md_set_array_sectors(mddev, size); + if (sectors > mddev->dev_sectors && + mddev->recovery_cp > oldsize) { + mddev->recovery_cp = oldsize; + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + } + calc_sectors(conf, sectors); + mddev->dev_sectors = conf->dev_sectors; + mddev->resync_max_sectors = size; + return 0; +} + +static void *raid10_takeover_raid0(struct mddev *mddev, sector_t size, int devs) +{ + struct md_rdev *rdev; + struct r10conf *conf; + + if (mddev->degraded > 0) { + pr_warn("md/raid10:%s: Error: degraded raid0!\n", + mdname(mddev)); + return ERR_PTR(-EINVAL); + } + sector_div(size, devs); + + /* Set new parameters */ + mddev->new_level = 10; + /* new layout: far_copies = 1, near_copies = 2 */ + mddev->new_layout = (1<<8) + 2; + mddev->new_chunk_sectors = mddev->chunk_sectors; + mddev->delta_disks = mddev->raid_disks; + mddev->raid_disks *= 2; + /* make sure it will be not marked as dirty */ + mddev->recovery_cp = MaxSector; + mddev->dev_sectors = size; + + conf = setup_conf(mddev); + if (!IS_ERR(conf)) { + rdev_for_each(rdev, mddev) + if (rdev->raid_disk >= 0) { + rdev->new_raid_disk = rdev->raid_disk * 2; + rdev->sectors = size; + } + } + + return conf; +} + +static void *raid10_takeover(struct mddev *mddev) +{ + struct r0conf *raid0_conf; + + /* raid10 can take over: + * raid0 - providing it has only two drives + */ + if (mddev->level == 0) { + /* for raid0 takeover only one zone is supported */ + raid0_conf = mddev->private; + if (raid0_conf->nr_strip_zones > 1) { + pr_warn("md/raid10:%s: cannot takeover raid 0 with more than one zone.\n", + mdname(mddev)); + return ERR_PTR(-EINVAL); + } + return raid10_takeover_raid0(mddev, + raid0_conf->strip_zone->zone_end, + raid0_conf->strip_zone->nb_dev); + } + return ERR_PTR(-EINVAL); +} + +static int raid10_check_reshape(struct mddev *mddev) +{ + /* Called when there is a request to change + * - layout (to ->new_layout) + * - chunk size (to ->new_chunk_sectors) + * - raid_disks (by delta_disks) + * or when trying to restart a reshape that was ongoing. + * + * We need to validate the request and possibly allocate + * space if that might be an issue later. + * + * Currently we reject any reshape of a 'far' mode array, + * allow chunk size to change if new is generally acceptable, + * allow raid_disks to increase, and allow + * a switch between 'near' mode and 'offset' mode. + */ + struct r10conf *conf = mddev->private; + struct geom geo; + + if (conf->geo.far_copies != 1 && !conf->geo.far_offset) + return -EINVAL; + + if (setup_geo(&geo, mddev, geo_start) != conf->copies) + /* mustn't change number of copies */ + return -EINVAL; + if (geo.far_copies > 1 && !geo.far_offset) + /* Cannot switch to 'far' mode */ + return -EINVAL; + + if (mddev->array_sectors & geo.chunk_mask) + /* not factor of array size */ + return -EINVAL; + + if (!enough(conf, -1)) + return -EINVAL; + + kfree(conf->mirrors_new); + conf->mirrors_new = NULL; + if (mddev->delta_disks > 0) { + /* allocate new 'mirrors' list */ + conf->mirrors_new = + kcalloc(mddev->raid_disks + mddev->delta_disks, + sizeof(struct raid10_info), + GFP_KERNEL); + if (!conf->mirrors_new) + return -ENOMEM; + } + return 0; +} + +/* + * Need to check if array has failed when deciding whether to: + * - start an array + * - remove non-faulty devices + * - add a spare + * - allow a reshape + * This determination is simple when no reshape is happening. + * However if there is a reshape, we need to carefully check + * both the before and after sections. + * This is because some failed devices may only affect one + * of the two sections, and some non-in_sync devices may + * be insync in the section most affected by failed devices. + */ +static int calc_degraded(struct r10conf *conf) +{ + int degraded, degraded2; + int i; + + rcu_read_lock(); + degraded = 0; + /* 'prev' section first */ + for (i = 0; i < conf->prev.raid_disks; i++) { + struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + if (!rdev || test_bit(Faulty, &rdev->flags)) + degraded++; + else if (!test_bit(In_sync, &rdev->flags)) + /* When we can reduce the number of devices in + * an array, this might not contribute to + * 'degraded'. It does now. + */ + degraded++; + } + rcu_read_unlock(); + if (conf->geo.raid_disks == conf->prev.raid_disks) + return degraded; + rcu_read_lock(); + degraded2 = 0; + for (i = 0; i < conf->geo.raid_disks; i++) { + struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); + if (!rdev || test_bit(Faulty, &rdev->flags)) + degraded2++; + else if (!test_bit(In_sync, &rdev->flags)) { + /* If reshape is increasing the number of devices, + * this section has already been recovered, so + * it doesn't contribute to degraded. + * else it does. + */ + if (conf->geo.raid_disks <= conf->prev.raid_disks) + degraded2++; + } + } + rcu_read_unlock(); + if (degraded2 > degraded) + return degraded2; + return degraded; +} + +static int raid10_start_reshape(struct mddev *mddev) +{ + /* A 'reshape' has been requested. This commits + * the various 'new' fields and sets MD_RECOVER_RESHAPE + * This also checks if there are enough spares and adds them + * to the array. + * We currently require enough spares to make the final + * array non-degraded. We also require that the difference + * between old and new data_offset - on each device - is + * enough that we never risk over-writing. + */ + + unsigned long before_length, after_length; + sector_t min_offset_diff = 0; + int first = 1; + struct geom new; + struct r10conf *conf = mddev->private; + struct md_rdev *rdev; + int spares = 0; + int ret; + + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) + return -EBUSY; + + if (setup_geo(&new, mddev, geo_start) != conf->copies) + return -EINVAL; + + before_length = ((1 << conf->prev.chunk_shift) * + conf->prev.far_copies); + after_length = ((1 << conf->geo.chunk_shift) * + conf->geo.far_copies); + + rdev_for_each(rdev, mddev) { + if (!test_bit(In_sync, &rdev->flags) + && !test_bit(Faulty, &rdev->flags)) + spares++; + if (rdev->raid_disk >= 0) { + long long diff = (rdev->new_data_offset + - rdev->data_offset); + if (!mddev->reshape_backwards) + diff = -diff; + if (diff < 0) + diff = 0; + if (first || diff < min_offset_diff) + min_offset_diff = diff; + first = 0; + } + } + + if (max(before_length, after_length) > min_offset_diff) + return -EINVAL; + + if (spares < mddev->delta_disks) + return -EINVAL; + + conf->offset_diff = min_offset_diff; + spin_lock_irq(&conf->device_lock); + if (conf->mirrors_new) { + memcpy(conf->mirrors_new, conf->mirrors, + sizeof(struct raid10_info)*conf->prev.raid_disks); + smp_mb(); + kfree(conf->mirrors_old); + conf->mirrors_old = conf->mirrors; + conf->mirrors = conf->mirrors_new; + conf->mirrors_new = NULL; + } + setup_geo(&conf->geo, mddev, geo_start); + smp_mb(); + if (mddev->reshape_backwards) { + sector_t size = raid10_size(mddev, 0, 0); + if (size < mddev->array_sectors) { + spin_unlock_irq(&conf->device_lock); + pr_warn("md/raid10:%s: array size must be reduce before number of disks\n", + mdname(mddev)); + return -EINVAL; + } + mddev->resync_max_sectors = size; + conf->reshape_progress = size; + } else + conf->reshape_progress = 0; + conf->reshape_safe = conf->reshape_progress; + spin_unlock_irq(&conf->device_lock); + + if (mddev->delta_disks && mddev->bitmap) { + struct mdp_superblock_1 *sb = NULL; + sector_t oldsize, newsize; + + oldsize = raid10_size(mddev, 0, 0); + newsize = raid10_size(mddev, 0, conf->geo.raid_disks); + + if (!mddev_is_clustered(mddev)) { + ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0); + if (ret) + goto abort; + else + goto out; + } + + rdev_for_each(rdev, mddev) { + if (rdev->raid_disk > -1 && + !test_bit(Faulty, &rdev->flags)) + sb = page_address(rdev->sb_page); + } + + /* + * some node is already performing reshape, and no need to + * call md_bitmap_resize again since it should be called when + * receiving BITMAP_RESIZE msg + */ + if ((sb && (le32_to_cpu(sb->feature_map) & + MD_FEATURE_RESHAPE_ACTIVE)) || (oldsize == newsize)) + goto out; + + ret = md_bitmap_resize(mddev->bitmap, newsize, 0, 0); + if (ret) + goto abort; + + ret = md_cluster_ops->resize_bitmaps(mddev, newsize, oldsize); + if (ret) { + md_bitmap_resize(mddev->bitmap, oldsize, 0, 0); + goto abort; + } + } +out: + if (mddev->delta_disks > 0) { + rdev_for_each(rdev, mddev) + if (rdev->raid_disk < 0 && + !test_bit(Faulty, &rdev->flags)) { + if (raid10_add_disk(mddev, rdev) == 0) { + if (rdev->raid_disk >= + conf->prev.raid_disks) + set_bit(In_sync, &rdev->flags); + else + rdev->recovery_offset = 0; + + /* Failure here is OK */ + sysfs_link_rdev(mddev, rdev); + } + } else if (rdev->raid_disk >= conf->prev.raid_disks + && !test_bit(Faulty, &rdev->flags)) { + /* This is a spare that was manually added */ + set_bit(In_sync, &rdev->flags); + } + } + /* When a reshape changes the number of devices, + * ->degraded is measured against the larger of the + * pre and post numbers. + */ + spin_lock_irq(&conf->device_lock); + mddev->degraded = calc_degraded(conf); + spin_unlock_irq(&conf->device_lock); + mddev->raid_disks = conf->geo.raid_disks; + mddev->reshape_position = conf->reshape_progress; + set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); + + clear_bit(MD_RECOVERY_SYNC, &mddev->recovery); + clear_bit(MD_RECOVERY_CHECK, &mddev->recovery); + clear_bit(MD_RECOVERY_DONE, &mddev->recovery); + set_bit(MD_RECOVERY_RESHAPE, &mddev->recovery); + set_bit(MD_RECOVERY_RUNNING, &mddev->recovery); + + rcu_assign_pointer(mddev->sync_thread, + md_register_thread(md_do_sync, mddev, "reshape")); + if (!mddev->sync_thread) { + ret = -EAGAIN; + goto abort; + } + conf->reshape_checkpoint = jiffies; + md_wakeup_thread(mddev->sync_thread); + md_new_event(); + return 0; + +abort: + mddev->recovery = 0; + spin_lock_irq(&conf->device_lock); + conf->geo = conf->prev; + mddev->raid_disks = conf->geo.raid_disks; + rdev_for_each(rdev, mddev) + rdev->new_data_offset = rdev->data_offset; + smp_wmb(); + conf->reshape_progress = MaxSector; + conf->reshape_safe = MaxSector; + mddev->reshape_position = MaxSector; + spin_unlock_irq(&conf->device_lock); + return ret; +} + +/* Calculate the last device-address that could contain + * any block from the chunk that includes the array-address 's' + * and report the next address. + * i.e. the address returned will be chunk-aligned and after + * any data that is in the chunk containing 's'. + */ +static sector_t last_dev_address(sector_t s, struct geom *geo) +{ + s = (s | geo->chunk_mask) + 1; + s >>= geo->chunk_shift; + s *= geo->near_copies; + s = DIV_ROUND_UP_SECTOR_T(s, geo->raid_disks); + s *= geo->far_copies; + s <<= geo->chunk_shift; + return s; +} + +/* Calculate the first device-address that could contain + * any block from the chunk that includes the array-address 's'. + * This too will be the start of a chunk + */ +static sector_t first_dev_address(sector_t s, struct geom *geo) +{ + s >>= geo->chunk_shift; + s *= geo->near_copies; + sector_div(s, geo->raid_disks); + s *= geo->far_copies; + s <<= geo->chunk_shift; + return s; +} + +static sector_t reshape_request(struct mddev *mddev, sector_t sector_nr, + int *skipped) +{ + /* We simply copy at most one chunk (smallest of old and new) + * at a time, possibly less if that exceeds RESYNC_PAGES, + * or we hit a bad block or something. + * This might mean we pause for normal IO in the middle of + * a chunk, but that is not a problem as mddev->reshape_position + * can record any location. + * + * If we will want to write to a location that isn't + * yet recorded as 'safe' (i.e. in metadata on disk) then + * we need to flush all reshape requests and update the metadata. + * + * When reshaping forwards (e.g. to more devices), we interpret + * 'safe' as the earliest block which might not have been copied + * down yet. We divide this by previous stripe size and multiply + * by previous stripe length to get lowest device offset that we + * cannot write to yet. + * We interpret 'sector_nr' as an address that we want to write to. + * From this we use last_device_address() to find where we might + * write to, and first_device_address on the 'safe' position. + * If this 'next' write position is after the 'safe' position, + * we must update the metadata to increase the 'safe' position. + * + * When reshaping backwards, we round in the opposite direction + * and perform the reverse test: next write position must not be + * less than current safe position. + * + * In all this the minimum difference in data offsets + * (conf->offset_diff - always positive) allows a bit of slack, + * so next can be after 'safe', but not by more than offset_diff + * + * We need to prepare all the bios here before we start any IO + * to ensure the size we choose is acceptable to all devices. + * The means one for each copy for write-out and an extra one for + * read-in. + * We store the read-in bio in ->master_bio and the others in + * ->devs[x].bio and ->devs[x].repl_bio. + */ + struct r10conf *conf = mddev->private; + struct r10bio *r10_bio; + sector_t next, safe, last; + int max_sectors; + int nr_sectors; + int s; + struct md_rdev *rdev; + int need_flush = 0; + struct bio *blist; + struct bio *bio, *read_bio; + int sectors_done = 0; + struct page **pages; + + if (sector_nr == 0) { + /* If restarting in the middle, skip the initial sectors */ + if (mddev->reshape_backwards && + conf->reshape_progress < raid10_size(mddev, 0, 0)) { + sector_nr = (raid10_size(mddev, 0, 0) + - conf->reshape_progress); + } else if (!mddev->reshape_backwards && + conf->reshape_progress > 0) + sector_nr = conf->reshape_progress; + if (sector_nr) { + mddev->curr_resync_completed = sector_nr; + sysfs_notify_dirent_safe(mddev->sysfs_completed); + *skipped = 1; + return sector_nr; + } + } + + /* We don't use sector_nr to track where we are up to + * as that doesn't work well for ->reshape_backwards. + * So just use ->reshape_progress. + */ + if (mddev->reshape_backwards) { + /* 'next' is the earliest device address that we might + * write to for this chunk in the new layout + */ + next = first_dev_address(conf->reshape_progress - 1, + &conf->geo); + + /* 'safe' is the last device address that we might read from + * in the old layout after a restart + */ + safe = last_dev_address(conf->reshape_safe - 1, + &conf->prev); + + if (next + conf->offset_diff < safe) + need_flush = 1; + + last = conf->reshape_progress - 1; + sector_nr = last & ~(sector_t)(conf->geo.chunk_mask + & conf->prev.chunk_mask); + if (sector_nr + RESYNC_SECTORS < last) + sector_nr = last + 1 - RESYNC_SECTORS; + } else { + /* 'next' is after the last device address that we + * might write to for this chunk in the new layout + */ + next = last_dev_address(conf->reshape_progress, &conf->geo); + + /* 'safe' is the earliest device address that we might + * read from in the old layout after a restart + */ + safe = first_dev_address(conf->reshape_safe, &conf->prev); + + /* Need to update metadata if 'next' might be beyond 'safe' + * as that would possibly corrupt data + */ + if (next > safe + conf->offset_diff) + need_flush = 1; + + sector_nr = conf->reshape_progress; + last = sector_nr | (conf->geo.chunk_mask + & conf->prev.chunk_mask); + + if (sector_nr + RESYNC_SECTORS <= last) + last = sector_nr + RESYNC_SECTORS - 1; + } + + if (need_flush || + time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) { + /* Need to update reshape_position in metadata */ + wait_barrier(conf, false); + mddev->reshape_position = conf->reshape_progress; + if (mddev->reshape_backwards) + mddev->curr_resync_completed = raid10_size(mddev, 0, 0) + - conf->reshape_progress; + else + mddev->curr_resync_completed = conf->reshape_progress; + conf->reshape_checkpoint = jiffies; + set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags); + md_wakeup_thread(mddev->thread); + wait_event(mddev->sb_wait, mddev->sb_flags == 0 || + test_bit(MD_RECOVERY_INTR, &mddev->recovery)); + if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) { + allow_barrier(conf); + return sectors_done; + } + conf->reshape_safe = mddev->reshape_position; + allow_barrier(conf); + } + + raise_barrier(conf, 0); +read_more: + /* Now schedule reads for blocks from sector_nr to last */ + r10_bio = raid10_alloc_init_r10buf(conf); + r10_bio->state = 0; + raise_barrier(conf, 1); + atomic_set(&r10_bio->remaining, 0); + r10_bio->mddev = mddev; + r10_bio->sector = sector_nr; + set_bit(R10BIO_IsReshape, &r10_bio->state); + r10_bio->sectors = last - sector_nr + 1; + rdev = read_balance(conf, r10_bio, &max_sectors); + BUG_ON(!test_bit(R10BIO_Previous, &r10_bio->state)); + + if (!rdev) { + /* Cannot read from here, so need to record bad blocks + * on all the target devices. + */ + // FIXME + mempool_free(r10_bio, &conf->r10buf_pool); + set_bit(MD_RECOVERY_INTR, &mddev->recovery); + return sectors_done; + } + + read_bio = bio_alloc_bioset(rdev->bdev, RESYNC_PAGES, REQ_OP_READ, + GFP_KERNEL, &mddev->bio_set); + read_bio->bi_iter.bi_sector = (r10_bio->devs[r10_bio->read_slot].addr + + rdev->data_offset); + read_bio->bi_private = r10_bio; + read_bio->bi_end_io = end_reshape_read; + r10_bio->master_bio = read_bio; + r10_bio->read_slot = r10_bio->devs[r10_bio->read_slot].devnum; + + /* + * Broadcast RESYNC message to other nodes, so all nodes would not + * write to the region to avoid conflict. + */ + if (mddev_is_clustered(mddev) && conf->cluster_sync_high <= sector_nr) { + struct mdp_superblock_1 *sb = NULL; + int sb_reshape_pos = 0; + + conf->cluster_sync_low = sector_nr; + conf->cluster_sync_high = sector_nr + CLUSTER_RESYNC_WINDOW_SECTORS; + sb = page_address(rdev->sb_page); + if (sb) { + sb_reshape_pos = le64_to_cpu(sb->reshape_position); + /* + * Set cluster_sync_low again if next address for array + * reshape is less than cluster_sync_low. Since we can't + * update cluster_sync_low until it has finished reshape. + */ + if (sb_reshape_pos < conf->cluster_sync_low) + conf->cluster_sync_low = sb_reshape_pos; + } + + md_cluster_ops->resync_info_update(mddev, conf->cluster_sync_low, + conf->cluster_sync_high); + } + + /* Now find the locations in the new layout */ + __raid10_find_phys(&conf->geo, r10_bio); + + blist = read_bio; + read_bio->bi_next = NULL; + + rcu_read_lock(); + for (s = 0; s < conf->copies*2; s++) { + struct bio *b; + int d = r10_bio->devs[s/2].devnum; + struct md_rdev *rdev2; + if (s&1) { + rdev2 = rcu_dereference(conf->mirrors[d].replacement); + b = r10_bio->devs[s/2].repl_bio; + } else { + rdev2 = rcu_dereference(conf->mirrors[d].rdev); + b = r10_bio->devs[s/2].bio; + } + if (!rdev2 || test_bit(Faulty, &rdev2->flags)) + continue; + + bio_set_dev(b, rdev2->bdev); + b->bi_iter.bi_sector = r10_bio->devs[s/2].addr + + rdev2->new_data_offset; + b->bi_end_io = end_reshape_write; + b->bi_opf = REQ_OP_WRITE; + b->bi_next = blist; + blist = b; + } + + /* Now add as many pages as possible to all of these bios. */ + + nr_sectors = 0; + pages = get_resync_pages(r10_bio->devs[0].bio)->pages; + for (s = 0 ; s < max_sectors; s += PAGE_SIZE >> 9) { + struct page *page = pages[s / (PAGE_SIZE >> 9)]; + int len = (max_sectors - s) << 9; + if (len > PAGE_SIZE) + len = PAGE_SIZE; + for (bio = blist; bio ; bio = bio->bi_next) { + if (WARN_ON(!bio_add_page(bio, page, len, 0))) { + bio->bi_status = BLK_STS_RESOURCE; + bio_endio(bio); + return sectors_done; + } + } + sector_nr += len >> 9; + nr_sectors += len >> 9; + } + rcu_read_unlock(); + r10_bio->sectors = nr_sectors; + + /* Now submit the read */ + md_sync_acct_bio(read_bio, r10_bio->sectors); + atomic_inc(&r10_bio->remaining); + read_bio->bi_next = NULL; + submit_bio_noacct(read_bio); + sectors_done += nr_sectors; + if (sector_nr <= last) + goto read_more; + + lower_barrier(conf); + + /* Now that we have done the whole section we can + * update reshape_progress + */ + if (mddev->reshape_backwards) + conf->reshape_progress -= sectors_done; + else + conf->reshape_progress += sectors_done; + + return sectors_done; +} + +static void end_reshape_request(struct r10bio *r10_bio); +static int handle_reshape_read_error(struct mddev *mddev, + struct r10bio *r10_bio); +static void reshape_request_write(struct mddev *mddev, struct r10bio *r10_bio) +{ + /* Reshape read completed. Hopefully we have a block + * to write out. + * If we got a read error then we do sync 1-page reads from + * elsewhere until we find the data - or give up. + */ + struct r10conf *conf = mddev->private; + int s; + + if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) + if (handle_reshape_read_error(mddev, r10_bio) < 0) { + /* Reshape has been aborted */ + md_done_sync(mddev, r10_bio->sectors, 0); + return; + } + + /* We definitely have the data in the pages, schedule the + * writes. + */ + atomic_set(&r10_bio->remaining, 1); + for (s = 0; s < conf->copies*2; s++) { + struct bio *b; + int d = r10_bio->devs[s/2].devnum; + struct md_rdev *rdev; + rcu_read_lock(); + if (s&1) { + rdev = rcu_dereference(conf->mirrors[d].replacement); + b = r10_bio->devs[s/2].repl_bio; + } else { + rdev = rcu_dereference(conf->mirrors[d].rdev); + b = r10_bio->devs[s/2].bio; + } + if (!rdev || test_bit(Faulty, &rdev->flags)) { + rcu_read_unlock(); + continue; + } + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + md_sync_acct_bio(b, r10_bio->sectors); + atomic_inc(&r10_bio->remaining); + b->bi_next = NULL; + submit_bio_noacct(b); + } + end_reshape_request(r10_bio); +} + +static void end_reshape(struct r10conf *conf) +{ + if (test_bit(MD_RECOVERY_INTR, &conf->mddev->recovery)) + return; + + spin_lock_irq(&conf->device_lock); + conf->prev = conf->geo; + md_finish_reshape(conf->mddev); + smp_wmb(); + conf->reshape_progress = MaxSector; + conf->reshape_safe = MaxSector; + spin_unlock_irq(&conf->device_lock); + + if (conf->mddev->queue) + raid10_set_io_opt(conf); + conf->fullsync = 0; +} + +static void raid10_update_reshape_pos(struct mddev *mddev) +{ + struct r10conf *conf = mddev->private; + sector_t lo, hi; + + md_cluster_ops->resync_info_get(mddev, &lo, &hi); + if (((mddev->reshape_position <= hi) && (mddev->reshape_position >= lo)) + || mddev->reshape_position == MaxSector) + conf->reshape_progress = mddev->reshape_position; + else + WARN_ON_ONCE(1); +} + +static int handle_reshape_read_error(struct mddev *mddev, + struct r10bio *r10_bio) +{ + /* Use sync reads to get the blocks from somewhere else */ + int sectors = r10_bio->sectors; + struct r10conf *conf = mddev->private; + struct r10bio *r10b; + int slot = 0; + int idx = 0; + struct page **pages; + + r10b = kmalloc(struct_size(r10b, devs, conf->copies), GFP_NOIO); + if (!r10b) { + set_bit(MD_RECOVERY_INTR, &mddev->recovery); + return -ENOMEM; + } + + /* reshape IOs share pages from .devs[0].bio */ + pages = get_resync_pages(r10_bio->devs[0].bio)->pages; + + r10b->sector = r10_bio->sector; + __raid10_find_phys(&conf->prev, r10b); + + while (sectors) { + int s = sectors; + int success = 0; + int first_slot = slot; + + if (s > (PAGE_SIZE >> 9)) + s = PAGE_SIZE >> 9; + + rcu_read_lock(); + while (!success) { + int d = r10b->devs[slot].devnum; + struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev); + sector_t addr; + if (rdev == NULL || + test_bit(Faulty, &rdev->flags) || + !test_bit(In_sync, &rdev->flags)) + goto failed; + + addr = r10b->devs[slot].addr + idx * PAGE_SIZE; + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); + success = sync_page_io(rdev, + addr, + s << 9, + pages[idx], + REQ_OP_READ, false); + rdev_dec_pending(rdev, mddev); + rcu_read_lock(); + if (success) + break; + failed: + slot++; + if (slot >= conf->copies) + slot = 0; + if (slot == first_slot) + break; + } + rcu_read_unlock(); + if (!success) { + /* couldn't read this block, must give up */ + set_bit(MD_RECOVERY_INTR, + &mddev->recovery); + kfree(r10b); + return -EIO; + } + sectors -= s; + idx++; + } + kfree(r10b); + return 0; +} + +static void end_reshape_write(struct bio *bio) +{ + struct r10bio *r10_bio = get_resync_r10bio(bio); + struct mddev *mddev = r10_bio->mddev; + struct r10conf *conf = mddev->private; + int d; + int slot; + int repl; + struct md_rdev *rdev = NULL; + + d = find_bio_disk(conf, r10_bio, bio, &slot, &repl); + if (repl) + rdev = conf->mirrors[d].replacement; + if (!rdev) { + smp_mb(); + rdev = conf->mirrors[d].rdev; + } + + if (bio->bi_status) { + /* FIXME should record badblock */ + md_error(mddev, rdev); + } + + rdev_dec_pending(rdev, mddev); + end_reshape_request(r10_bio); +} + +static void end_reshape_request(struct r10bio *r10_bio) +{ + if (!atomic_dec_and_test(&r10_bio->remaining)) + return; + md_done_sync(r10_bio->mddev, r10_bio->sectors, 1); + bio_put(r10_bio->master_bio); + put_buf(r10_bio); +} + +static void raid10_finish_reshape(struct mddev *mddev) +{ + struct r10conf *conf = mddev->private; + + if (test_bit(MD_RECOVERY_INTR, &mddev->recovery)) + return; + + if (mddev->delta_disks > 0) { + if (mddev->recovery_cp > mddev->resync_max_sectors) { + mddev->recovery_cp = mddev->resync_max_sectors; + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + } + mddev->resync_max_sectors = mddev->array_sectors; + } else { + int d; + rcu_read_lock(); + for (d = conf->geo.raid_disks ; + d < conf->geo.raid_disks - mddev->delta_disks; + d++) { + struct md_rdev *rdev = rcu_dereference(conf->mirrors[d].rdev); + if (rdev) + clear_bit(In_sync, &rdev->flags); + rdev = rcu_dereference(conf->mirrors[d].replacement); + if (rdev) + clear_bit(In_sync, &rdev->flags); + } + rcu_read_unlock(); + } + mddev->layout = mddev->new_layout; + mddev->chunk_sectors = 1 << conf->geo.chunk_shift; + mddev->reshape_position = MaxSector; + mddev->delta_disks = 0; + mddev->reshape_backwards = 0; +} + +static struct md_personality raid10_personality = +{ + .name = "raid10", + .level = 10, + .owner = THIS_MODULE, + .make_request = raid10_make_request, + .run = raid10_run, + .free = raid10_free, + .status = raid10_status, + .error_handler = raid10_error, + .hot_add_disk = raid10_add_disk, + .hot_remove_disk= raid10_remove_disk, + .spare_active = raid10_spare_active, + .sync_request = raid10_sync_request, + .quiesce = raid10_quiesce, + .size = raid10_size, + .resize = raid10_resize, + .takeover = raid10_takeover, + .check_reshape = raid10_check_reshape, + .start_reshape = raid10_start_reshape, + .finish_reshape = raid10_finish_reshape, + .update_reshape_pos = raid10_update_reshape_pos, +}; + +static int __init raid_init(void) +{ + return register_md_personality(&raid10_personality); +} + +static void raid_exit(void) +{ + unregister_md_personality(&raid10_personality); +} + +module_init(raid_init); +module_exit(raid_exit); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("RAID10 (striped mirror) personality for MD"); +MODULE_ALIAS("md-personality-9"); /* RAID10 */ +MODULE_ALIAS("md-raid10"); +MODULE_ALIAS("md-level-10"); |