| /* |
| * 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. |
| * |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2, or (at your option) |
| * any later version. |
| * |
| * You should have received a copy of the GNU General Public License |
| * (for example /usr/src/linux/COPYING); if not, write to the Free |
| * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| #include <linux/blkdev.h> |
| #include <linux/module.h> |
| #include <linux/seq_file.h> |
| #include <linux/ratelimit.h> |
| #include <linux/kthread.h> |
| #include "md.h" |
| #include "raid10.h" |
| #include "raid0.h" |
| #include "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] |
| */ |
| |
| /* |
| * Number of guaranteed r10bios in case of extreme VM load: |
| */ |
| #define NR_RAID10_BIOS 256 |
| |
| /* when we get a read error on a read-only array, we redirect to another |
| * device without failing the first device, or trying to over-write to |
| * correct the read error. To keep track of bad blocks on a per-bio |
| * level, we store IO_BLOCKED in the appropriate 'bios' pointer |
| */ |
| #define IO_BLOCKED ((struct bio *)1) |
| /* When we successfully write to a known bad-block, we need to remove the |
| * bad-block marking which must be done from process context. So we record |
| * the success by setting devs[n].bio to IO_MADE_GOOD |
| */ |
| #define IO_MADE_GOOD ((struct bio *)2) |
| |
| #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2) |
| |
| /* When there are this many requests queued to be written by |
| * the raid10 thread, we become 'congested' to provide back-pressure |
| * for writeback. |
| */ |
| static int max_queued_requests = 1024; |
| |
| 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 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); |
| |
| static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) |
| { |
| struct r10conf *conf = data; |
| int size = offsetof(struct r10bio, devs[conf->copies]); |
| |
| /* allocate a r10bio with room for raid_disks entries in the |
| * bios array */ |
| return kzalloc(size, gfp_flags); |
| } |
| |
| static void r10bio_pool_free(void *r10_bio, void *data) |
| { |
| kfree(r10_bio); |
| } |
| |
| /* Maximum size of each resync request */ |
| #define RESYNC_BLOCK_SIZE (64*1024) |
| #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) |
| /* 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) |
| |
| /* |
| * 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 page *page; |
| struct r10bio *r10_bio; |
| struct bio *bio; |
| int i, j; |
| int nalloc; |
| |
| 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 bios. |
| */ |
| for (j = nalloc ; j-- ; ) { |
| bio = bio_kmalloc(gfp_flags, RESYNC_PAGES); |
| if (!bio) |
| goto out_free_bio; |
| r10_bio->devs[j].bio = bio; |
| if (!conf->have_replacement) |
| continue; |
| bio = bio_kmalloc(gfp_flags, RESYNC_PAGES); |
| if (!bio) |
| goto out_free_bio; |
| 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; |
| bio = r10_bio->devs[j].bio; |
| for (i = 0; i < RESYNC_PAGES; i++) { |
| if (j > 0 && !test_bit(MD_RECOVERY_SYNC, |
| &conf->mddev->recovery)) { |
| /* we can share bv_page's during recovery |
| * and reshape */ |
| struct bio *rbio = r10_bio->devs[0].bio; |
| page = rbio->bi_io_vec[i].bv_page; |
| get_page(page); |
| } else |
| page = alloc_page(gfp_flags); |
| if (unlikely(!page)) |
| goto out_free_pages; |
| |
| bio->bi_io_vec[i].bv_page = page; |
| if (rbio) |
| rbio->bi_io_vec[i].bv_page = page; |
| } |
| } |
| |
| return r10_bio; |
| |
| out_free_pages: |
| for ( ; i > 0 ; i--) |
| safe_put_page(bio->bi_io_vec[i-1].bv_page); |
| while (j--) |
| for (i = 0; i < RESYNC_PAGES ; i++) |
| safe_put_page(r10_bio->devs[j].bio->bi_io_vec[i].bv_page); |
| j = 0; |
| out_free_bio: |
| for ( ; j < nalloc; j++) { |
| if (r10_bio->devs[j].bio) |
| bio_put(r10_bio->devs[j].bio); |
| if (r10_bio->devs[j].repl_bio) |
| bio_put(r10_bio->devs[j].repl_bio); |
| } |
| r10bio_pool_free(r10_bio, conf); |
| return NULL; |
| } |
| |
| static void r10buf_pool_free(void *__r10_bio, void *data) |
| { |
| int i; |
| struct r10conf *conf = data; |
| struct r10bio *r10bio = __r10_bio; |
| int j; |
| |
| for (j=0; j < conf->copies; j++) { |
| struct bio *bio = r10bio->devs[j].bio; |
| if (bio) { |
| for (i = 0; i < RESYNC_PAGES; i++) { |
| safe_put_page(bio->bi_io_vec[i].bv_page); |
| bio->bi_io_vec[i].bv_page = NULL; |
| } |
| bio_put(bio); |
| } |
| bio = r10bio->devs[j].repl_bio; |
| if (bio) |
| bio_put(bio); |
| } |
| r10bio_pool_free(r10bio, conf); |
| } |
| |
| static void put_all_bios(struct r10conf *conf, struct r10bio *r10_bio) |
| { |
| int i; |
| |
| for (i = 0; i < conf->copies; 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 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; |
| int done; |
| struct r10conf *conf = r10_bio->mddev->private; |
| |
| if (bio->bi_phys_segments) { |
| unsigned long flags; |
| spin_lock_irqsave(&conf->device_lock, flags); |
| bio->bi_phys_segments--; |
| done = (bio->bi_phys_segments == 0); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| } else |
| done = 1; |
| if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) |
| bio->bi_error = -EIO; |
| if (done) { |
| 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->copies; slot++) { |
| if (r10_bio->devs[slot].bio == bio) |
| break; |
| if (r10_bio->devs[slot].repl_bio == bio) { |
| repl = 1; |
| break; |
| } |
| } |
| |
| BUG_ON(slot == conf->copies); |
| 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_error; |
| struct r10bio *r10_bio = bio->bi_private; |
| int slot, dev; |
| struct md_rdev *rdev; |
| struct r10conf *conf = r10_bio->mddev->private; |
| |
| slot = r10_bio->read_slot; |
| dev = r10_bio->devs[slot].devnum; |
| 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 |
| */ |
| char b[BDEVNAME_SIZE]; |
| printk_ratelimited(KERN_ERR |
| "md/raid10:%s: %s: rescheduling sector %llu\n", |
| mdname(conf->mddev), |
| bdevname(rdev->bdev, b), |
| (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 */ |
| 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; |
| |
| 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_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); |
| set_bit(R10BIO_WriteError, &r10_bio->state); |
| dec_rdev = 0; |
| } |
| } 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)) { |
| 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); |
| } |
| |
| /* |
| * 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_rdev, *rdev = NULL; |
| int do_balance; |
| int best_slot; |
| struct geom *geo = &conf->geo; |
| |
| raid10_find_phys(conf, r10_bio); |
| rcu_read_lock(); |
| retry: |
| sectors = r10_bio->sectors; |
| best_slot = -1; |
| best_rdev = NULL; |
| best_dist = MaxSector; |
| best_good_sectors = 0; |
| do_balance = 1; |
| /* |
| * 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)) |
| do_balance = 0; |
| |
| for (slot = 0; slot < conf->copies ; slot++) { |
| sector_t first_bad; |
| int bad_sectors; |
| sector_t dev_sector; |
| |
| 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) |
| 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_slot = slot; |
| best_rdev = rdev; |
| } |
| if (!do_balance) |
| /* Must read from here */ |
| break; |
| } |
| continue; |
| } else |
| best_good_sectors = sectors; |
| |
| if (!do_balance) |
| break; |
| |
| /* 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 && !atomic_read(&rdev->nr_pending)) |
| break; |
| |
| /* for far > 1 always use the lowest address */ |
| 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_slot = slot; |
| best_rdev = rdev; |
| } |
| } |
| if (slot >= conf->copies) { |
| slot = best_slot; |
| rdev = best_rdev; |
| } |
| |
| if (slot >= 0) { |
| atomic_inc(&rdev->nr_pending); |
| if (test_bit(Faulty, &rdev->flags)) { |
| /* Cannot risk returning a device that failed |
| * before we inc'ed nr_pending |
| */ |
| rdev_dec_pending(rdev, conf->mddev); |
| goto retry; |
| } |
| r10_bio->read_slot = slot; |
| } else |
| rdev = NULL; |
| rcu_read_unlock(); |
| *max_sectors = best_good_sectors; |
| |
| return rdev; |
| } |
| |
| static int raid10_congested(struct mddev *mddev, int bits) |
| { |
| struct r10conf *conf = mddev->private; |
| int i, ret = 0; |
| |
| if ((bits & (1 << WB_async_congested)) && |
| conf->pending_count >= max_queued_requests) |
| return 1; |
| |
| rcu_read_lock(); |
| for (i = 0; |
| (i < conf->geo.raid_disks || i < conf->prev.raid_disks) |
| && ret == 0; |
| i++) { |
| struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev); |
| if (rdev && !test_bit(Faulty, &rdev->flags)) { |
| struct request_queue *q = bdev_get_queue(rdev->bdev); |
| |
| ret |= bdi_congested(&q->backing_dev_info, bits); |
| } |
| } |
| rcu_read_unlock(); |
| return ret; |
| } |
| |
| 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 bio *bio; |
| bio = bio_list_get(&conf->pending_bio_list); |
| conf->pending_count = 0; |
| spin_unlock_irq(&conf->device_lock); |
| /* flush any pending bitmap writes to disk |
| * before proceeding w/ I/O */ |
| bitmap_unplug(conf->mddev->bitmap); |
| wake_up(&conf->wait_barrier); |
| |
| while (bio) { /* submit pending writes */ |
| struct bio *next = bio->bi_next; |
| bio->bi_next = NULL; |
| if (unlikely((bio->bi_rw & REQ_DISCARD) && |
| !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) |
| /* Just ignore it */ |
| bio_endio(bio); |
| else |
| generic_make_request(bio); |
| bio = next; |
| } |
| } else |
| spin_unlock_irq(&conf->device_lock); |
| } |
| |
| /* Barriers.... |
| * Sometimes we need to suspend IO while we do something else, |
| * either some resync/recovery, or reconfigure the array. |
| * To do this we raise a 'barrier'. |
| * The 'barrier' is a counter that can be raised multiple times |
| * to count how many activities are happening which preclude |
| * normal IO. |
| * We can only raise the barrier if there is no pending IO. |
| * i.e. if nr_pending == 0. |
| * We choose only to raise the barrier if no-one is waiting for the |
| * barrier to go down. This means that as soon as an IO request |
| * is ready, no other operations which require a barrier will start |
| * until the IO request has had a chance. |
| * |
| * So: regular IO calls 'wait_barrier'. When that returns there |
| * is no backgroup IO happening, It must arrange to call |
| * allow_barrier when it has finished its IO. |
| * backgroup IO calls must call raise_barrier. Once that returns |
| * there is no normal IO happeing. It must arrange to call |
| * lower_barrier when the particular background IO completes. |
| */ |
| |
| static void raise_barrier(struct r10conf *conf, int force) |
| { |
| BUG_ON(force && !conf->barrier); |
| spin_lock_irq(&conf->resync_lock); |
| |
| /* Wait until no block IO is waiting (unless 'force') */ |
| wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting, |
| conf->resync_lock); |
| |
| /* block any new IO from starting */ |
| conf->barrier++; |
| |
| /* Now wait for all pending IO to complete */ |
| wait_event_lock_irq(conf->wait_barrier, |
| !conf->nr_pending && conf->barrier < RESYNC_DEPTH, |
| conf->resync_lock); |
| |
| spin_unlock_irq(&conf->resync_lock); |
| } |
| |
| static void lower_barrier(struct r10conf *conf) |
| { |
| unsigned long flags; |
| spin_lock_irqsave(&conf->resync_lock, flags); |
| conf->barrier--; |
| spin_unlock_irqrestore(&conf->resync_lock, flags); |
| wake_up(&conf->wait_barrier); |
| } |
| |
| static void wait_barrier(struct r10conf *conf) |
| { |
| spin_lock_irq(&conf->resync_lock); |
| if (conf->barrier) { |
| conf->nr_waiting++; |
| /* Wait for the barrier to drop. |
| * However if there are already pending |
| * requests (preventing the barrier from |
| * rising completely), and the |
| * pre-process bio queue isn't empty, |
| * then don't wait, as we need to empty |
| * that queue to get the nr_pending |
| * count down. |
| */ |
| wait_event_lock_irq(conf->wait_barrier, |
| !conf->barrier || |
| (conf->nr_pending && |
| current->bio_list && |
| !bio_list_empty(current->bio_list)), |
| conf->resync_lock); |
| conf->nr_waiting--; |
| } |
| conf->nr_pending++; |
| spin_unlock_irq(&conf->resync_lock); |
| } |
| |
| static void allow_barrier(struct r10conf *conf) |
| { |
| unsigned long flags; |
| spin_lock_irqsave(&conf->resync_lock, flags); |
| conf->nr_pending--; |
| spin_unlock_irqrestore(&conf->resync_lock, flags); |
| wake_up(&conf->wait_barrier); |
| } |
| |
| static void freeze_array(struct 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. |
| */ |
| spin_lock_irq(&conf->resync_lock); |
| conf->barrier++; |
| conf->nr_waiting++; |
| wait_event_lock_irq_cmd(conf->wait_barrier, |
| conf->nr_pending == conf->nr_queued+extra, |
| conf->resync_lock, |
| flush_pending_writes(conf)); |
| |
| spin_unlock_irq(&conf->resync_lock); |
| } |
| |
| static void unfreeze_array(struct r10conf *conf) |
| { |
| /* reverse the effect of the freeze */ |
| spin_lock_irq(&conf->resync_lock); |
| conf->barrier--; |
| conf->nr_waiting--; |
| wake_up(&conf->wait_barrier); |
| spin_unlock_irq(&conf->resync_lock); |
| } |
| |
| 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; |
| } |
| |
| struct raid10_plug_cb { |
| struct blk_plug_cb cb; |
| struct bio_list pending; |
| int pending_cnt; |
| }; |
| |
| static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule) |
| { |
| struct raid10_plug_cb *plug = container_of(cb, struct raid10_plug_cb, |
| cb); |
| struct mddev *mddev = plug->cb.data; |
| struct r10conf *conf = mddev->private; |
| struct bio *bio; |
| |
| if (from_schedule || current->bio_list) { |
| spin_lock_irq(&conf->device_lock); |
| bio_list_merge(&conf->pending_bio_list, &plug->pending); |
| conf->pending_count += plug->pending_cnt; |
| spin_unlock_irq(&conf->device_lock); |
| wake_up(&conf->wait_barrier); |
| md_wakeup_thread(mddev->thread); |
| kfree(plug); |
| return; |
| } |
| |
| /* we aren't scheduling, so we can do the write-out directly. */ |
| bio = bio_list_get(&plug->pending); |
| bitmap_unplug(mddev->bitmap); |
| wake_up(&conf->wait_barrier); |
| |
| while (bio) { /* submit pending writes */ |
| struct bio *next = bio->bi_next; |
| bio->bi_next = NULL; |
| if (unlikely((bio->bi_rw & REQ_DISCARD) && |
| !blk_queue_discard(bdev_get_queue(bio->bi_bdev)))) |
| /* Just ignore it */ |
| bio_endio(bio); |
| else |
| generic_make_request(bio); |
| bio = next; |
| } |
| kfree(plug); |
| } |
| |
| static void __make_request(struct mddev *mddev, struct bio *bio) |
| { |
| struct r10conf *conf = mddev->private; |
| struct r10bio *r10_bio; |
| struct bio *read_bio; |
| int i; |
| const int rw = bio_data_dir(bio); |
| const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); |
| const unsigned long do_fua = (bio->bi_rw & REQ_FUA); |
| const unsigned long do_discard = (bio->bi_rw |
| & (REQ_DISCARD | REQ_SECURE)); |
| const unsigned long do_same = (bio->bi_rw & REQ_WRITE_SAME); |
| unsigned long flags; |
| struct md_rdev *blocked_rdev; |
| struct blk_plug_cb *cb; |
| struct raid10_plug_cb *plug = NULL; |
| int sectors_handled; |
| int max_sectors; |
| int sectors; |
| |
| /* |
| * Register the new request and wait if the reconstruction |
| * thread has put up a bar for new requests. |
| * Continue immediately if no resync is active currently. |
| */ |
| wait_barrier(conf); |
| |
| sectors = bio_sectors(bio); |
| 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) { |
| /* IO spans the reshape position. Need to wait for |
| * reshape to pass |
| */ |
| allow_barrier(conf); |
| 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); |
| } |
| if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) && |
| bio_data_dir(bio) == WRITE && |
| (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_bit(MD_CHANGE_DEVS, &mddev->flags); |
| set_bit(MD_CHANGE_PENDING, &mddev->flags); |
| md_wakeup_thread(mddev->thread); |
| wait_event(mddev->sb_wait, |
| !test_bit(MD_CHANGE_PENDING, &mddev->flags)); |
| |
| conf->reshape_safe = mddev->reshape_position; |
| } |
| |
| 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; |
| |
| /* We might need to issue multiple reads to different |
| * devices if there are bad blocks around, so we keep |
| * track of the number of reads in bio->bi_phys_segments. |
| * If this is 0, there is only one r10_bio and no locking |
| * will be needed when the request completes. If it is |
| * non-zero, then it is the number of not-completed requests. |
| */ |
| bio->bi_phys_segments = 0; |
| bio_clear_flag(bio, BIO_SEG_VALID); |
| |
| if (rw == READ) { |
| /* |
| * read balancing logic: |
| */ |
| struct md_rdev *rdev; |
| int slot; |
| |
| read_again: |
| rdev = read_balance(conf, r10_bio, &max_sectors); |
| if (!rdev) { |
| raid_end_bio_io(r10_bio); |
| return; |
| } |
| slot = r10_bio->read_slot; |
| |
| read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
| bio_trim(read_bio, r10_bio->sector - bio->bi_iter.bi_sector, |
| max_sectors); |
| |
| 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_bdev = rdev->bdev; |
| read_bio->bi_end_io = raid10_end_read_request; |
| read_bio->bi_rw = READ | do_sync; |
| read_bio->bi_private = r10_bio; |
| |
| if (max_sectors < r10_bio->sectors) { |
| /* Could not read all from this device, so we will |
| * need another r10_bio. |
| */ |
| sectors_handled = (r10_bio->sector + max_sectors |
| - bio->bi_iter.bi_sector); |
| r10_bio->sectors = max_sectors; |
| spin_lock_irq(&conf->device_lock); |
| if (bio->bi_phys_segments == 0) |
| bio->bi_phys_segments = 2; |
| else |
| bio->bi_phys_segments++; |
| spin_unlock_irq(&conf->device_lock); |
| /* Cannot call generic_make_request directly |
| * as that will be queued in __generic_make_request |
| * and subsequent mempool_alloc might block |
| * waiting for it. so hand bio over to raid10d. |
| */ |
| reschedule_retry(r10_bio); |
| |
| r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); |
| |
| r10_bio->master_bio = bio; |
| r10_bio->sectors = bio_sectors(bio) - sectors_handled; |
| r10_bio->state = 0; |
| r10_bio->mddev = mddev; |
| r10_bio->sector = bio->bi_iter.bi_sector + |
| sectors_handled; |
| goto read_again; |
| } else |
| generic_make_request(read_bio); |
| return; |
| } |
| |
| /* |
| * WRITE: |
| */ |
| if (conf->pending_count >= max_queued_requests) { |
| md_wakeup_thread(mddev->thread); |
| wait_event(conf->wait_barrier, |
| conf->pending_count < max_queued_requests); |
| } |
| /* first select target devices under rcu_lock and |
| * inc refcount on their rdev. Record them by setting |
| * bios[x] to bio |
| * If there are known/acknowledged bad blocks on any device |
| * on which we have seen a write error, we want to avoid |
| * writing 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. The number |
| * of r10_bios is recored in bio->bi_phys_segments just as with |
| * the read case. |
| */ |
| |
| r10_bio->read_slot = -1; /* make sure repl_bio gets freed */ |
| raid10_find_phys(conf, r10_bio); |
| retry_write: |
| blocked_rdev = NULL; |
| 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 = rcu_dereference(conf->mirrors[d].rdev); |
| struct md_rdev *rrdev = rcu_dereference( |
| conf->mirrors[d].replacement); |
| if (rdev == rrdev) |
| rrdev = NULL; |
| 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(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 < 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; |
| } |
| 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 (unlikely(blocked_rdev)) { |
| /* Have to wait for this device to get unblocked, then retry */ |
| int j; |
| int d; |
| |
| for (j = 0; j < i; j++) { |
| if (r10_bio->devs[j].bio) { |
| d = r10_bio->devs[j].devnum; |
| rdev_dec_pending(conf->mirrors[d].rdev, mddev); |
| } |
| if (r10_bio->devs[j].repl_bio) { |
| struct md_rdev *rdev; |
| d = r10_bio->devs[j].devnum; |
| rdev = conf->mirrors[d].replacement; |
| if (!rdev) { |
| /* Race with remove_disk */ |
| smp_mb(); |
| rdev = conf->mirrors[d].rdev; |
| } |
| rdev_dec_pending(rdev, mddev); |
| } |
| } |
| allow_barrier(conf); |
| md_wait_for_blocked_rdev(blocked_rdev, mddev); |
| wait_barrier(conf); |
| goto retry_write; |
| } |
| |
| if (max_sectors < r10_bio->sectors) { |
| /* We are splitting this into multiple parts, so |
| * we need to prepare for allocating another r10_bio. |
| */ |
| r10_bio->sectors = max_sectors; |
| spin_lock_irq(&conf->device_lock); |
| if (bio->bi_phys_segments == 0) |
| bio->bi_phys_segments = 2; |
| else |
| bio->bi_phys_segments++; |
| spin_unlock_irq(&conf->device_lock); |
| } |
| sectors_handled = r10_bio->sector + max_sectors - |
| bio->bi_iter.bi_sector; |
| |
| atomic_set(&r10_bio->remaining, 1); |
| bitmap_startwrite(mddev->bitmap, r10_bio->sector, r10_bio->sectors, 0); |
| |
| for (i = 0; i < conf->copies; i++) { |
| struct bio *mbio; |
| int d = r10_bio->devs[i].devnum; |
| if (r10_bio->devs[i].bio) { |
| struct md_rdev *rdev = conf->mirrors[d].rdev; |
| mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
| bio_trim(mbio, r10_bio->sector - bio->bi_iter.bi_sector, |
| max_sectors); |
| r10_bio->devs[i].bio = mbio; |
| |
| mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr+ |
| choose_data_offset(r10_bio, |
| rdev)); |
| mbio->bi_bdev = rdev->bdev; |
| mbio->bi_end_io = raid10_end_write_request; |
| mbio->bi_rw = |
| WRITE | do_sync | do_fua | do_discard | do_same; |
| mbio->bi_private = r10_bio; |
| |
| atomic_inc(&r10_bio->remaining); |
| |
| cb = blk_check_plugged(raid10_unplug, mddev, |
| sizeof(*plug)); |
| if (cb) |
| plug = container_of(cb, struct raid10_plug_cb, |
| cb); |
| else |
| plug = NULL; |
| spin_lock_irqsave(&conf->device_lock, flags); |
| if (plug) { |
| bio_list_add(&plug->pending, mbio); |
| plug->pending_cnt++; |
| } else { |
| bio_list_add(&conf->pending_bio_list, mbio); |
| conf->pending_count++; |
| } |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| if (!plug) |
| md_wakeup_thread(mddev->thread); |
| } |
| |
| if (r10_bio->devs[i].repl_bio) { |
| struct md_rdev *rdev = conf->mirrors[d].replacement; |
| if (rdev == NULL) { |
| /* Replacement just got moved to main 'rdev' */ |
| smp_mb(); |
| rdev = conf->mirrors[d].rdev; |
| } |
| mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
| bio_trim(mbio, r10_bio->sector - bio->bi_iter.bi_sector, |
| max_sectors); |
| r10_bio->devs[i].repl_bio = mbio; |
| |
| mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr + |
| choose_data_offset( |
| r10_bio, rdev)); |
| mbio->bi_bdev = rdev->bdev; |
| mbio->bi_end_io = raid10_end_write_request; |
| mbio->bi_rw = |
| WRITE | do_sync | do_fua | do_discard | do_same; |
| mbio->bi_private = r10_bio; |
| |
| atomic_inc(&r10_bio->remaining); |
| spin_lock_irqsave(&conf->device_lock, flags); |
| bio_list_add(&conf->pending_bio_list, mbio); |
| conf->pending_count++; |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| if (!mddev_check_plugged(mddev)) |
| md_wakeup_thread(mddev->thread); |
| } |
| } |
| |
| /* Don't remove the bias on 'remaining' (one_write_done) until |
| * after checking if we need to go around again. |
| */ |
| |
| if (sectors_handled < bio_sectors(bio)) { |
| one_write_done(r10_bio); |
| /* We need another r10_bio. It has already been counted |
| * in bio->bi_phys_segments. |
| */ |
| r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); |
| |
| r10_bio->master_bio = bio; |
| r10_bio->sectors = bio_sectors(bio) - sectors_handled; |
| |
| r10_bio->mddev = mddev; |
| r10_bio->sector = bio->bi_iter.bi_sector + sectors_handled; |
| r10_bio->state = 0; |
| goto retry_write; |
| } |
| one_write_done(r10_bio); |
| } |
| |
| static void 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; |
| |
| struct bio *split; |
| |
| if (unlikely(bio->bi_rw & REQ_FLUSH)) { |
| md_flush_request(mddev, bio); |
| return; |
| } |
| |
| md_write_start(mddev, bio); |
| |
| do { |
| |
| /* |
| * If this request crosses a chunk boundary, we need to split |
| * it. |
| */ |
| if (unlikely((bio->bi_iter.bi_sector & chunk_mask) + |
| bio_sectors(bio) > chunk_sects |
| && (conf->geo.near_copies < conf->geo.raid_disks |
| || conf->prev.near_copies < |
| conf->prev.raid_disks))) { |
| split = bio_split(bio, chunk_sects - |
| (bio->bi_iter.bi_sector & |
| (chunk_sects - 1)), |
| GFP_NOIO, fs_bio_set); |
| bio_chain(split, bio); |
| } else { |
| split = bio; |
| } |
| |
| __make_request(mddev, split); |
| } while (split != bio); |
| |
| /* In case raid10d snuck in to freeze_array */ |
| wake_up(&conf->wait_barrier); |
| } |
| |
| static void 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); |
| for (i = 0; i < conf->geo.raid_disks; i++) |
| seq_printf(seq, "%s", |
| conf->mirrors[i].rdev && |
| test_bit(In_sync, &conf->mirrors[i].rdev->flags) ? "U" : "_"); |
| 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); |
| } |
| |
| static void error(struct mddev *mddev, struct md_rdev *rdev) |
| { |
| char b[BDEVNAME_SIZE]; |
| struct r10conf *conf = mddev->private; |
| unsigned long flags; |
| |
| /* |
| * If it is not operational, then we have already marked it as dead |
| * else if it is the last working disks, ignore the error, let the |
| * next level up know. |
| * else mark the drive as failed |
| */ |
| spin_lock_irqsave(&conf->device_lock, flags); |
| if (test_bit(In_sync, &rdev->flags) |
| && !enough(conf, rdev->raid_disk)) { |
| /* |
| * Don't fail the drive, just return an IO error. |
| */ |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| return; |
| } |
| if (test_and_clear_bit(In_sync, &rdev->flags)) |
| mddev->degraded++; |
| /* |
| * If recovery is running, make sure it aborts. |
| */ |
| set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
| set_bit(Blocked, &rdev->flags); |
| set_bit(Faulty, &rdev->flags); |
| set_bit(MD_CHANGE_DEVS, &mddev->flags); |
| set_bit(MD_CHANGE_PENDING, &mddev->flags); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| printk(KERN_ALERT |
| "md/raid10:%s: Disk failure on %s, disabling device.\n" |
| "md/raid10:%s: Operation continuing on %d devices.\n", |
| mdname(mddev), bdevname(rdev->bdev, b), |
| mdname(mddev), conf->geo.raid_disks - mddev->degraded); |
| } |
| |
| static void print_conf(struct r10conf *conf) |
| { |
| int i; |
| struct raid10_info *tmp; |
| |
| printk(KERN_DEBUG "RAID10 conf printout:\n"); |
| if (!conf) { |
| printk(KERN_DEBUG "(!conf)\n"); |
| return; |
| } |
| printk(KERN_DEBUG " --- wd:%d rd:%d\n", conf->geo.raid_disks - conf->mddev->degraded, |
| conf->geo.raid_disks); |
| |
| for (i = 0; i < conf->geo.raid_disks; i++) { |
| char b[BDEVNAME_SIZE]; |
| tmp = conf->mirrors + i; |
| if (tmp->rdev) |
| printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n", |
| i, !test_bit(In_sync, &tmp->rdev->flags), |
| !test_bit(Faulty, &tmp->rdev->flags), |
| bdevname(tmp->rdev->bdev,b)); |
| } |
| } |
| |
| static void close_sync(struct r10conf *conf) |
| { |
| wait_barrier(conf); |
| allow_barrier(conf); |
| |
| mempool_destroy(conf->r10buf_pool); |
| conf->r10buf_pool = NULL; |
| } |
| |
| 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; |
| int first = 0; |
| int last = conf->geo.raid_disks - 1; |
| |
| 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 && |
| conf->mirrors[rdev->saved_raid_disk].rdev == NULL) |
| mirror = rdev->saved_raid_disk; |
| else |
| mirror = first; |
| for ( ; mirror <= last ; mirror++) { |
| struct raid10_info *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) |
| continue; |
| clear_bit(In_sync, &rdev->flags); |
| set_bit(Replacement, &rdev->flags); |
| rdev->raid_disk = mirror; |
| 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); |
| break; |
| } |
| |
| 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 (mddev->queue && blk_queue_discard(bdev_get_queue(rdev->bdev))) |
| queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, mddev->queue); |
| |
| print_conf(conf); |
| return err; |
| } |
| |
| static int 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 = conf->mirrors + number; |
| |
| print_conf(conf); |
| 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 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; |
| synchronize_rcu(); |
| if (atomic_read(&rdev->nr_pending)) { |
| /* lost the race, try later */ |
| err = -EBUSY; |
| *rdevp = rdev; |
| goto abort; |
| } else 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); |
| } else |
| /* We might have just remove the Replacement as faulty |
| * Clear the flag just in case |
| */ |
| clear_bit(WantReplacement, &rdev->flags); |
| |
| err = md_integrity_register(mddev); |
| |
| abort: |
| |
| print_conf(conf); |
| return err; |
| } |
| |
| static void end_sync_read(struct bio *bio) |
| { |
| struct r10bio *r10_bio = bio->bi_private; |
| struct r10conf *conf = r10_bio->mddev->private; |
| int d; |
| |
| if (bio == r10_bio->master_bio) { |
| /* this is a reshape read */ |
| d = r10_bio->read_slot; /* really the read dev */ |
| } else |
| d = find_bio_disk(conf, r10_bio, bio, NULL, NULL); |
| |
| if (!bio->bi_error) |
| 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_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 = bio->bi_private; |
| 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_error) { |
| 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; |
| |
| 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_error) |
| 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; |
| |
| 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; |
| |
| tbio = r10_bio->devs[i].bio; |
| |
| if (tbio->bi_end_io != end_sync_read) |
| continue; |
| if (i == first) |
| continue; |
| if (!r10_bio->devs[i].bio->bi_error) { |
| /* 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(fbio->bi_io_vec[j].bv_page), |
| page_address(tbio->bi_io_vec[j].bv_page), |
| 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; |
| } |
| /* 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 |
| */ |
| bio_reset(tbio); |
| |
| tbio->bi_vcnt = vcnt; |
| tbio->bi_iter.bi_size = fbio->bi_iter.bi_size; |
| tbio->bi_rw = WRITE; |
| tbio->bi_private = r10_bio; |
| tbio->bi_iter.bi_sector = r10_bio->devs[i].addr; |
| tbio->bi_end_io = end_sync_write; |
| |
| bio_copy_data(tbio, fbio); |
| |
| d = r10_bio->devs[i].devnum; |
| atomic_inc(&conf->mirrors[d].rdev->nr_pending); |
| atomic_inc(&r10_bio->remaining); |
| md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(tbio)); |
| |
| tbio->bi_iter.bi_sector += conf->mirrors[d].rdev->data_offset; |
| tbio->bi_bdev = conf->mirrors[d].rdev->bdev; |
| generic_make_request(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)); |
| generic_make_request(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; |
| |
| 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, |
| bio->bi_io_vec[idx].bv_page, |
| READ, false); |
| if (ok) { |
| rdev = conf->mirrors[dw].rdev; |
| addr = r10_bio->devs[1].addr + sect; |
| ok = sync_page_io(rdev, |
| addr, |
| s << 9, |
| bio->bi_io_vec[idx].bv_page, |
| 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 */ |
| printk(KERN_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, *wbio2; |
| |
| if (!test_bit(R10BIO_Uptodate, &r10_bio->state)) { |
| fix_recovery_read_error(r10_bio); |
| end_sync_request(r10_bio); |
| return; |
| } |
| |
| /* |
| * share the pages with the first bio |
| * and submit the write request |
| */ |
| d = r10_bio->devs[1].devnum; |
| wbio = r10_bio->devs[1].bio; |
| wbio2 = r10_bio->devs[1].repl_bio; |
| /* Need to test wbio2->bi_end_io before we call |
| * generic_make_request as if the former is NULL, |
| * the latter is free to free wbio2. |
| */ |
| if (wbio2 && !wbio2->bi_end_io) |
| wbio2 = NULL; |
| if (wbio->bi_end_io) { |
| atomic_inc(&conf->mirrors[d].rdev->nr_pending); |
| md_sync_acct(conf->mirrors[d].rdev->bdev, bio_sectors(wbio)); |
| generic_make_request(wbio); |
| } |
| if (wbio2) { |
| atomic_inc(&conf->mirrors[d].replacement->nr_pending); |
| md_sync_acct(conf->mirrors[d].replacement->bdev, |
| bio_sectors(wbio2)); |
| generic_make_request(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) |
| { |
| struct timespec cur_time_mon; |
| unsigned long hours_since_last; |
| unsigned int read_errors = atomic_read(&rdev->read_errors); |
| |
| ktime_get_ts(&cur_time_mon); |
| |
| if (rdev->last_read_error.tv_sec == 0 && |
| rdev->last_read_error.tv_nsec == 0) { |
| /* first time we've seen a read error */ |
| rdev->last_read_error = cur_time_mon; |
| return; |
| } |
| |
| hours_since_last = (cur_time_mon.tv_sec - |
| rdev->last_read_error.tv_sec) / 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, int rw) |
| { |
| sector_t first_bad; |
| int bad_sectors; |
| |
| if (is_badblock(rdev, sector, sectors, &first_bad, &bad_sectors) |
| && (rw == READ || test_bit(WriteErrorSeen, &rdev->flags))) |
| return -1; |
| if (sync_page_io(rdev, sector, sectors << 9, page, rw, false)) |
| /* success */ |
| return 1; |
| if (rw == WRITE) { |
| set_bit(WriteErrorSeen, &rdev->flags); |
| if (!test_and_set_bit(WantReplacement, &rdev->flags)) |
| set_bit(MD_RECOVERY_NEEDED, |
| &rdev->mddev->recovery); |
| } |
| /* need to record an error - either for the block or the device */ |
| if (!rdev_set_badblocks(rdev, sector, sectors, 0)) |
| md_error(rdev->mddev, rdev); |
| return 0; |
| } |
| |
| /* |
| * 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; |
| struct md_rdev*rdev; |
| int max_read_errors = atomic_read(&mddev->max_corr_read_errors); |
| int d = r10_bio->devs[r10_bio->read_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) { |
| char b[BDEVNAME_SIZE]; |
| bdevname(rdev->bdev, b); |
| |
| printk(KERN_NOTICE |
| "md/raid10:%s: %s: Raid device exceeded " |
| "read_error threshold [cur %d:max %d]\n", |
| mdname(mddev), b, |
| atomic_read(&rdev->read_errors), max_read_errors); |
| printk(KERN_NOTICE |
| "md/raid10:%s: %s: Failing raid device\n", |
| mdname(mddev), b); |
| md_error(mddev, conf->mirrors[d].rdev); |
| r10_bio->devs[r10_bio->read_slot].bio = IO_BLOCKED; |
| return; |
| } |
| |
| while(sectors) { |
| int s = sectors; |
| int sl = r10_bio->read_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) && |
| 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, READ, false); |
| rdev_dec_pending(rdev, mddev); |
| rcu_read_lock(); |
| if (success) |
| break; |
| } |
| sl++; |
| if (sl == conf->copies) |
| sl = 0; |
| } while (!success && sl != r10_bio->read_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[r10_bio->read_slot].devnum; |
| rdev = conf->mirrors[dn].rdev; |
| |
| if (!rdev_set_badblocks( |
| rdev, |
| r10_bio->devs[r10_bio->read_slot].addr |
| + sect, |
| s, 0)) { |
| md_error(mddev, rdev); |
| r10_bio->devs[r10_bio->read_slot].bio |
| = IO_BLOCKED; |
| } |
| break; |
| } |
| |
| start = sl; |
| /* write it back and re-read */ |
| rcu_read_lock(); |
| while (sl != r10_bio->read_slot) { |
| char b[BDEVNAME_SIZE]; |
| |
| if (sl==0) |
| sl = conf->copies; |
| sl--; |
| d = r10_bio->devs[sl].devnum; |
| rdev = rcu_dereference(conf->mirrors[d].rdev); |
| if (!rdev || |
| !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, WRITE) |
| == 0) { |
| /* Well, this device is dead */ |
| printk(KERN_NOTICE |
| "md/raid10:%s: read correction " |
| "write failed" |
| " (%d sectors at %llu on %s)\n", |
| mdname(mddev), s, |
| (unsigned long long)( |
| sect + |
| choose_data_offset(r10_bio, |
| rdev)), |
| bdevname(rdev->bdev, b)); |
| printk(KERN_NOTICE "md/raid10:%s: %s: failing " |
| "drive\n", |
| mdname(mddev), |
| bdevname(rdev->bdev, b)); |
| } |
| rdev_dec_pending(rdev, mddev); |
| rcu_read_lock(); |
| } |
| sl = start; |
| while (sl != r10_bio->read_slot) { |
| char b[BDEVNAME_SIZE]; |
| |
| if (sl==0) |
| sl = conf->copies; |
| sl--; |
| d = r10_bio->devs[sl].devnum; |
| rdev = rcu_dereference(conf->mirrors[d].rdev); |
| if (!rdev || |
| !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, |
| READ)) { |
| case 0: |
| /* Well, this device is dead */ |
| printk(KERN_NOTICE |
| "md/raid10:%s: unable to read back " |
| "corrected sectors" |
| " (%d sectors at %llu on %s)\n", |
| mdname(mddev), s, |
| (unsigned long long)( |
| sect + |
| choose_data_offset(r10_bio, rdev)), |
| bdevname(rdev->bdev, b)); |
| printk(KERN_NOTICE "md/raid10:%s: %s: failing " |
| "drive\n", |
| mdname(mddev), |
| bdevname(rdev->bdev, b)); |
| break; |
| case 1: |
| printk(KERN_INFO |
| "md/raid10:%s: read error corrected" |
| " (%d sectors at %llu on %s)\n", |
| mdname(mddev), s, |
| (unsigned long long)( |
| sect + |
| choose_data_offset(r10_bio, rdev)), |
| bdevname(rdev->bdev, b)); |
| 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; |
| if (sectors > sect_to_write) |
| sectors = sect_to_write; |
| /* Write at 'sector' for 'sectors' */ |
| wbio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
| bio_trim(wbio, sector - bio->bi_iter.bi_sector, sectors); |
| wbio->bi_iter.bi_sector = (r10_bio->devs[i].addr+ |
| choose_data_offset(r10_bio, rdev) + |
| (sector - r10_bio->sector)); |
| wbio->bi_bdev = rdev->bdev; |
| if (submit_bio_wait(WRITE, wbio) < 0) |
| /* Failure! */ |
| ok = rdev_set_badblocks(rdev, sector, |
| sectors, 0) |
| && ok; |
| |
| bio_put(wbio); |
| sect_to_write -= sectors; |
| sector += sectors; |
| sectors = block_sectors; |
| } |
| return ok; |
| } |
| |
| static void handle_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; |
| char b[BDEVNAME_SIZE]; |
| unsigned long do_sync; |
| int max_sectors; |
| |
| /* 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; |
| bdevname(bio->bi_bdev, b); |
| bio_put(bio); |
| r10_bio->devs[slot].bio = NULL; |
| |
| if (mddev->ro == 0) { |
| freeze_array(conf, 1); |
| fix_read_error(conf, mddev, r10_bio); |
| unfreeze_array(conf); |
| } else |
| r10_bio->devs[slot].bio = IO_BLOCKED; |
| |
| rdev_dec_pending(rdev, mddev); |
| |
| read_more: |
| rdev = read_balance(conf, r10_bio, &max_sectors); |
| if (rdev == NULL) { |
| printk(KERN_ALERT "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; |
| } |
| |
| do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC); |
| slot = r10_bio->read_slot; |
| printk_ratelimited( |
| KERN_ERR |
| "md/raid10:%s: %s: redirecting " |
| "sector %llu to another mirror\n", |
| mdname(mddev), |
| bdevname(rdev->bdev, b), |
| (unsigned long long)r10_bio->sector); |
| bio = bio_clone_mddev(r10_bio->master_bio, |
| GFP_NOIO, mddev); |
| bio_trim(bio, r10_bio->sector - bio->bi_iter.bi_sector, max_sectors); |
| r10_bio->devs[slot].bio = bio; |
| r10_bio->devs[slot].rdev = rdev; |
| bio->bi_iter.bi_sector = r10_bio->devs[slot].addr |
| + choose_data_offset(r10_bio, rdev); |
| bio->bi_bdev = rdev->bdev; |
| bio->bi_rw = READ | do_sync; |
| bio->bi_private = r10_bio; |
| bio->bi_end_io = raid10_end_read_request; |
| if (max_sectors < r10_bio->sectors) { |
| /* Drat - have to split this up more */ |
| struct bio *mbio = r10_bio->master_bio; |
| int sectors_handled = |
| r10_bio->sector + max_sectors |
| - mbio->bi_iter.bi_sector; |
| r10_bio->sectors = max_sectors; |
| spin_lock_irq(&conf->device_lock); |
| if (mbio->bi_phys_segments == 0) |
| mbio->bi_phys_segments = 2; |
| else |
| mbio->bi_phys_segments++; |
| spin_unlock_irq(&conf->device_lock); |
| generic_make_request(bio); |
| |
| r10_bio = mempool_alloc(conf->r10bio_pool, |
| GFP_NOIO); |
| r10_bio->master_bio = mbio; |
| r10_bio->sectors = bio_sectors(mbio) - sectors_handled; |
| r10_bio->state = 0; |
| set_bit(R10BIO_ReadError, |
| &r10_bio->state); |
| r10_bio->mddev = mddev; |
| r10_bio->sector = mbio->bi_iter.bi_sector |
| + sectors_handled; |
| |
| goto read_more; |
| } else |
| generic_make_request(bio); |
| } |
| |
| 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) |
| continue; |
| if (!r10_bio->devs[m].bio->bi_error) { |
| 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) |
| continue; |
| |
| if (!r10_bio->devs[m].repl_bio->bi_error) { |
| 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_error) { |
| 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); |
| 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_CHANGE_PENDING, &mddev->flags)) { |
| LIST_HEAD(tmp); |
| spin_lock_irqsave(&conf->device_lock, flags); |
| if (!test_bit(MD_CHANGE_PENDING, &mddev->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 { |
| /* just a partial read to be scheduled from a |
| * separate context |
| */ |
| int slot = r10_bio->read_slot; |
| generic_make_request(r10_bio->devs[slot].bio); |
| } |
| |
| cond_resched(); |
| if (mddev->flags & ~(1<<MD_CHANGE_PENDING)) |
| md_check_recovery(mddev); |
| } |
| blk_finish_plug(&plug); |
| } |
| |
| static int init_resync(struct r10conf *conf) |
| { |
| int buffs; |
| int i; |
| |
| buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; |
| BUG_ON(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; |
| conf->r10buf_pool = mempool_create(buffs, r10buf_pool_alloc, r10buf_pool_free, conf); |
| if (!conf->r10buf_pool) |
| return -ENOMEM; |
| conf->next_resync = 0; |
| return 0; |
| } |
| |
| /* |
| * perform a "sync" on one "block" |
| * |
| * We need to make sure that no normal I/O request - particularly write |
| * requests - conflict with active sync requests. |
| * |
| * This is achieved by tracking pending requests and a 'barrier' concept |
| * that can be installed to exclude normal IO requests. |
| * |
| * 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 generic_make_request. |
| * |
| * 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 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; |
| |
| if (!conf->r10buf_pool) |
| if (init_resync(conf)) |
| return 0; |
| |
| /* |
| * 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; |
| } |
| |
| 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) { |
| /* 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)) |
| 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); |
| 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. |
| */ |
| for (i = 0; i < conf->geo.raid_disks; i++) |
| if (conf->mirrors[i].replacement) |
| conf->mirrors[i].replacement |
| ->recovery_offset |
| = MaxSector; |
| } |
| conf->fullsync = 0; |
| } |
| 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) { |
| /* 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; |
| |
| /* 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]; |
| |
| if ((mirror->rdev == NULL || |
| test_bit(In_sync, &mirror->rdev->flags)) |
| && |
| (mirror->replacement == NULL || |
| test_bit(Faulty, |
| &mirror->replacement->flags))) |
| 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. |
| */ |
| 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 = bitmap_start_sync(mddev->bitmap, sect, |
| &sync_blocks, 1); |
| if (sync_blocks < max_sync) |
| max_sync = sync_blocks; |
| if (!must_sync && |
| mirror->replacement == 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; |
| continue; |
| } |
| |
| r10_bio = mempool_alloc(conf->r10buf_pool, GFP_NOIO); |
| 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); |
|