diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/md/raid10.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/md/raid10.c | 3584 |
1 files changed, 0 insertions, 3584 deletions
diff --git a/ANDROID_3.4.5/drivers/md/raid10.c b/ANDROID_3.4.5/drivers/md/raid10.c deleted file mode 100644 index a954c95d..00000000 --- a/ANDROID_3.4.5/drivers/md/raid10.c +++ /dev/null @@ -1,3584 +0,0 @@ -/* - * 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 "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 ) - * - * 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 they 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 be very far apart - * on disk, there are adjacent stripes. - */ - -/* - * Number of guaranteed r10bios in case of extreme VM load: - */ -#define NR_RAID10_BIOS 256 - -/* When there are this many requests queue 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 ignore); - -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)) - 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 == 1 && !test_bit(MD_RECOVERY_SYNC, - &conf->mddev->recovery)) { - /* we can share bv_page's during recovery */ - 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 = -1; -out_free_bio: - while (++j < nalloc) { - 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)) - clear_bit(BIO_UPTODATE, &bio->bi_flags); - if (done) { - bio_endio(bio, 0); - /* - * Wake up any possible resync thread that waits for the device - * to go idle. - */ - allow_barrier(conf); - } - 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 error) -{ - int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - 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" - */ - unsigned long flags; - spin_lock_irqsave(&conf->device_lock, flags); - if (!enough(conf, rdev->raid_disk)) - uptodate = 1; - spin_unlock_irqrestore(&conf->device_lock, flags); - } - 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, int error) -{ - int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - 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 (!uptodate) { - 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; - - 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(conf->mirrors[dev].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 r10conf *conf, struct r10bio *r10bio) -{ - int n,f; - sector_t sector; - sector_t chunk; - sector_t stripe; - int dev; - - int slot = 0; - - /* now calculate first sector/dev */ - chunk = r10bio->sector >> conf->chunk_shift; - sector = r10bio->sector & conf->chunk_mask; - - chunk *= conf->near_copies; - stripe = chunk; - dev = sector_div(stripe, conf->raid_disks); - if (conf->far_offset) - stripe *= conf->far_copies; - - sector += stripe << conf->chunk_shift; - - /* and calculate all the others */ - for (n=0; n < conf->near_copies; n++) { - int d = dev; - sector_t s = sector; - r10bio->devs[slot].addr = sector; - r10bio->devs[slot].devnum = d; - slot++; - - for (f = 1; f < conf->far_copies; f++) { - d += conf->near_copies; - if (d >= conf->raid_disks) - d -= conf->raid_disks; - s += conf->stride; - r10bio->devs[slot].devnum = d; - r10bio->devs[slot].addr = s; - slot++; - } - dev++; - if (dev >= conf->raid_disks) { - dev = 0; - sector += (conf->chunk_mask + 1); - } - } - BUG_ON(slot != conf->copies); -} - -static sector_t raid10_find_virt(struct r10conf *conf, sector_t sector, int dev) -{ - sector_t offset, chunk, vchunk; - - offset = sector & conf->chunk_mask; - if (conf->far_offset) { - int fc; - chunk = sector >> conf->chunk_shift; - fc = sector_div(chunk, conf->far_copies); - dev -= fc * conf->near_copies; - if (dev < 0) - dev += conf->raid_disks; - } else { - while (sector >= conf->stride) { - sector -= conf->stride; - if (dev < conf->near_copies) - dev += conf->raid_disks - conf->near_copies; - else - dev -= conf->near_copies; - } - chunk = sector >> conf->chunk_shift; - } - vchunk = chunk * conf->raid_disks + dev; - sector_div(vchunk, conf->near_copies); - return (vchunk << conf->chunk_shift) + offset; -} - -/** - * raid10_mergeable_bvec -- tell bio layer if a two requests can be merged - * @q: request queue - * @bvm: properties of new bio - * @biovec: the request that could be merged to it. - * - * Return amount of bytes we can accept at this offset - * This requires checking for end-of-chunk if near_copies != raid_disks, - * and for subordinate merge_bvec_fns if merge_check_needed. - */ -static int raid10_mergeable_bvec(struct request_queue *q, - struct bvec_merge_data *bvm, - struct bio_vec *biovec) -{ - struct mddev *mddev = q->queuedata; - struct r10conf *conf = mddev->private; - sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); - int max; - unsigned int chunk_sectors = mddev->chunk_sectors; - unsigned int bio_sectors = bvm->bi_size >> 9; - - if (conf->near_copies < conf->raid_disks) { - max = (chunk_sectors - ((sector & (chunk_sectors - 1)) - + bio_sectors)) << 9; - if (max < 0) - /* bio_add cannot handle a negative return */ - max = 0; - if (max <= biovec->bv_len && bio_sectors == 0) - return biovec->bv_len; - } else - max = biovec->bv_len; - - if (mddev->merge_check_needed) { - struct r10bio r10_bio; - int s; - r10_bio.sector = sector; - raid10_find_phys(conf, &r10_bio); - rcu_read_lock(); - for (s = 0; s < conf->copies; s++) { - int disk = r10_bio.devs[s].devnum; - struct md_rdev *rdev = rcu_dereference( - conf->mirrors[disk].rdev); - if (rdev && !test_bit(Faulty, &rdev->flags)) { - struct request_queue *q = - bdev_get_queue(rdev->bdev); - if (q->merge_bvec_fn) { - bvm->bi_sector = r10_bio.devs[s].addr - + rdev->data_offset; - bvm->bi_bdev = rdev->bdev; - max = min(max, q->merge_bvec_fn( - q, bvm, biovec)); - } - } - rdev = rcu_dereference(conf->mirrors[disk].replacement); - if (rdev && !test_bit(Faulty, &rdev->flags)) { - struct request_queue *q = - bdev_get_queue(rdev->bdev); - if (q->merge_bvec_fn) { - bvm->bi_sector = r10_bio.devs[s].addr - + rdev->data_offset; - bvm->bi_bdev = rdev->bdev; - max = min(max, q->merge_bvec_fn( - q, bvm, biovec)); - } - } - } - rcu_read_unlock(); - } - return max; -} - -/* - * 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 *rdev, *best_rdev; - int do_balance; - int best_slot; - - 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) || - test_bit(Unmerged, &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) || - test_bit(Unmerged, &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 (conf->near_copies > 1 && !atomic_read(&rdev->nr_pending)) - break; - - /* for far > 1 always use the lowest address */ - if (conf->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(void *data, int bits) -{ - struct mddev *mddev = data; - struct r10conf *conf = mddev->private; - int i, ret = 0; - - if ((bits & (1 << BDI_async_congested)) && - conf->pending_count >= max_queued_requests) - return 1; - - if (mddev_congested(mddev, bits)) - return 1; - rcu_read_lock(); - for (i = 0; i < conf->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; - 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) -{ - /* 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+1 - * This is called in the context of one normal IO request - * that has failed. Thus any sync request that might be pending - * will be blocked by nr_pending, and we need to wait for - * pending IO requests to complete or be queued for re-try. - * Thus the number queued (nr_queued) plus this request (1) - * must match the number of pending IOs (nr_pending) before - * we continue. - */ - spin_lock_irq(&conf->resync_lock); - conf->barrier++; - conf->nr_waiting++; - wait_event_lock_irq(conf->wait_barrier, - conf->nr_pending == conf->nr_queued+1, - conf->resync_lock, - flush_pending_writes(conf)); - - spin_unlock_irq(&conf->resync_lock); -} - -static void unfreeze_array(struct 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 void make_request(struct mddev *mddev, struct bio * bio) -{ - struct r10conf *conf = mddev->private; - struct r10bio *r10_bio; - struct bio *read_bio; - int i; - int chunk_sects = conf->chunk_mask + 1; - 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); - unsigned long flags; - struct md_rdev *blocked_rdev; - int plugged; - int sectors_handled; - int max_sectors; - - if (unlikely(bio->bi_rw & REQ_FLUSH)) { - md_flush_request(mddev, bio); - return; - } - - /* If this request crosses a chunk boundary, we need to - * split it. This will only happen for 1 PAGE (or less) requests. - */ - if (unlikely( (bio->bi_sector & conf->chunk_mask) + (bio->bi_size >> 9) - > chunk_sects && - conf->near_copies < conf->raid_disks)) { - struct bio_pair *bp; - /* Sanity check -- queue functions should prevent this happening */ - if (bio->bi_vcnt != 1 || - bio->bi_idx != 0) - goto bad_map; - /* This is a one page bio that upper layers - * refuse to split for us, so we need to split it. - */ - bp = bio_split(bio, - chunk_sects - (bio->bi_sector & (chunk_sects - 1)) ); - - /* Each of these 'make_request' calls will call 'wait_barrier'. - * If the first succeeds but the second blocks due to the resync - * thread raising the barrier, we will deadlock because the - * IO to the underlying device will be queued in generic_make_request - * and will never complete, so will never reduce nr_pending. - * So increment nr_waiting here so no new raise_barriers will - * succeed, and so the second wait_barrier cannot block. - */ - spin_lock_irq(&conf->resync_lock); - conf->nr_waiting++; - spin_unlock_irq(&conf->resync_lock); - - make_request(mddev, &bp->bio1); - make_request(mddev, &bp->bio2); - - spin_lock_irq(&conf->resync_lock); - conf->nr_waiting--; - wake_up(&conf->wait_barrier); - spin_unlock_irq(&conf->resync_lock); - - bio_pair_release(bp); - return; - bad_map: - printk("md/raid10:%s: make_request bug: can't convert block across chunks" - " or bigger than %dk %llu %d\n", mdname(mddev), chunk_sects/2, - (unsigned long long)bio->bi_sector, bio->bi_size >> 10); - - bio_io_error(bio); - return; - } - - md_write_start(mddev, bio); - - /* - * 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); - - r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO); - - r10_bio->master_bio = bio; - r10_bio->sectors = bio->bi_size >> 9; - - r10_bio->mddev = mddev; - r10_bio->sector = bio->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; - clear_bit(BIO_SEG_VALID, &bio->bi_flags); - - 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); - md_trim_bio(read_bio, r10_bio->sector - bio->bi_sector, - max_sectors); - - r10_bio->devs[slot].bio = read_bio; - r10_bio->devs[slot].rdev = rdev; - - read_bio->bi_sector = r10_bio->devs[slot].addr + - rdev->data_offset; - 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->sectors + max_sectors - - bio->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(&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->bi_size >> 9) - - sectors_handled); - r10_bio->state = 0; - r10_bio->mddev = mddev; - r10_bio->sector = bio->bi_sector + sectors_handled; - goto read_again; - } else - generic_make_request(read_bio); - return; - } - - /* - * WRITE: - */ - if (conf->pending_count >= max_queued_requests) { - md_wakeup_thread(mddev->thread); - wait_event(conf->wait_barrier, - conf->pending_count < max_queued_requests); - } - /* first select target devices under rcu_lock and - * inc refcount on their rdev. Record them by setting - * bios[x] to bio - * If there are known/acknowledged bad blocks on any device - * on which we have seen a write error, we want to avoid - * writing 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. - */ - plugged = mddev_check_plugged(mddev); - - 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 (rrdev && (test_bit(Faulty, &rrdev->flags) - || test_bit(Unmerged, &rrdev->flags))) - rrdev = NULL; - - r10_bio->devs[i].bio = NULL; - r10_bio->devs[i].repl_bio = NULL; - if (!rdev || test_bit(Faulty, &rdev->flags) || - test_bit(Unmerged, &rdev->flags)) { - set_bit(R10BIO_Degraded, &r10_bio->state); - continue; - } - if (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; - } - } - 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_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) - continue; - - mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(mbio, r10_bio->sector - bio->bi_sector, - max_sectors); - r10_bio->devs[i].bio = mbio; - - mbio->bi_sector = (r10_bio->devs[i].addr+ - conf->mirrors[d].rdev->data_offset); - mbio->bi_bdev = conf->mirrors[d].rdev->bdev; - mbio->bi_end_io = raid10_end_write_request; - mbio->bi_rw = WRITE | do_sync | do_fua; - 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 (!r10_bio->devs[i].repl_bio) - continue; - - mbio = bio_clone_mddev(bio, GFP_NOIO, mddev); - md_trim_bio(mbio, r10_bio->sector - bio->bi_sector, - max_sectors); - r10_bio->devs[i].repl_bio = mbio; - - /* We are actively writing to the original device - * so it cannot disappear, so the replacement cannot - * become NULL here - */ - mbio->bi_sector = (r10_bio->devs[i].addr+ - conf->mirrors[d].replacement->data_offset); - mbio->bi_bdev = conf->mirrors[d].replacement->bdev; - mbio->bi_end_io = raid10_end_write_request; - mbio->bi_rw = WRITE | do_sync | do_fua; - 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); - } - - /* Don't remove the bias on 'remaining' (one_write_done) until - * after checking if we need to go around again. - */ - - if (sectors_handled < (bio->bi_size >> 9)) { - 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->bi_size >> 9) - sectors_handled; - - r10_bio->mddev = mddev; - r10_bio->sector = bio->bi_sector + sectors_handled; - r10_bio->state = 0; - goto retry_write; - } - one_write_done(r10_bio); - - /* In case raid10d snuck in to freeze_array */ - wake_up(&conf->wait_barrier); - - if (do_sync || !mddev->bitmap || !plugged) - md_wakeup_thread(mddev->thread); -} - -static void status(struct seq_file *seq, struct mddev *mddev) -{ - struct r10conf *conf = mddev->private; - int i; - - if (conf->near_copies < conf->raid_disks) - seq_printf(seq, " %dK chunks", mddev->chunk_sectors / 2); - if (conf->near_copies > 1) - seq_printf(seq, " %d near-copies", conf->near_copies); - if (conf->far_copies > 1) { - if (conf->far_offset) - seq_printf(seq, " %d offset-copies", conf->far_copies); - else - seq_printf(seq, " %d far-copies", conf->far_copies); - } - seq_printf(seq, " [%d/%d] [", conf->raid_disks, - conf->raid_disks - mddev->degraded); - for (i = 0; i < conf->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 ignore) -{ - int first = 0; - - do { - int n = conf->copies; - int cnt = 0; - while (n--) { - if (conf->mirrors[first].rdev && - first != ignore) - cnt++; - first = (first+1) % conf->raid_disks; - } - if (cnt == 0) - return 0; - } while (first != 0); - return 1; -} - -static void error(struct mddev *mddev, struct md_rdev *rdev) -{ - char b[BDEVNAME_SIZE]; - struct r10conf *conf = mddev->private; - - /* - * If it is not operational, then we have already marked it as dead - * else if it is the last working disks, ignore the error, let the - * next level up know. - * else mark the drive as failed - */ - if (test_bit(In_sync, &rdev->flags) - && !enough(conf, rdev->raid_disk)) - /* - * Don't fail the drive, just return an IO error. - */ - return; - if (test_and_clear_bit(In_sync, &rdev->flags)) { - unsigned long flags; - spin_lock_irqsave(&conf->device_lock, flags); - mddev->degraded++; - spin_unlock_irqrestore(&conf->device_lock, flags); - /* - * 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); - 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->raid_disks - mddev->degraded); -} - -static void print_conf(struct r10conf *conf) -{ - int i; - struct mirror_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->raid_disks - conf->mddev->degraded, - conf->raid_disks); - - for (i = 0; i < conf->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 mirror_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->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 - && !test_bit(Faulty, &tmp->rdev->flags) - && !test_and_set_bit(In_sync, &tmp->rdev->flags)) { - count++; - sysfs_notify_dirent(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->raid_disks - 1; - struct request_queue *q = bdev_get_queue(rdev->bdev); - - 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)) - return -EINVAL; - - if (rdev->raid_disk >= 0) - first = last = rdev->raid_disk; - - if (q->merge_bvec_fn) { - set_bit(Unmerged, &rdev->flags); - mddev->merge_check_needed = 1; - } - - 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 mirror_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; - disk_stack_limits(mddev->gendisk, rdev->bdev, - rdev->data_offset << 9); - conf->fullsync = 1; - rcu_assign_pointer(p->replacement, rdev); - break; - } - - 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 == 0 && test_bit(Unmerged, &rdev->flags)) { - /* Some requests might not have seen this new - * merge_bvec_fn. We must wait for them to complete - * before merging the device fully. - * First we make sure any code which has tested - * our function has submitted the request, then - * we wait for all outstanding requests to complete. - */ - synchronize_sched(); - raise_barrier(conf, 0); - lower_barrier(conf); - clear_bit(Unmerged, &rdev->flags); - } - md_integrity_add_rdev(rdev, mddev); - 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 mirror_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) && - 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, int error) -{ - struct r10bio *r10_bio = bio->bi_private; - struct r10conf *conf = r10_bio->mddev->private; - int d; - - d = find_bio_disk(conf, r10_bio, bio, NULL, NULL); - - if (test_bit(BIO_UPTODATE, &bio->bi_flags)) - 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, int error) -{ - int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); - 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 (!uptodate) { - 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 (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) - break; - - if (i == conf->copies) - goto done; - - first = i; - fbio = r10_bio->devs[i].bio; - - 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 (test_bit(BIO_UPTODATE, &r10_bio->devs[i].bio->bi_flags)) { - /* 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; - */ - for (j = 0; j < vcnt; j++) - if (memcmp(page_address(fbio->bi_io_vec[j].bv_page), - page_address(tbio->bi_io_vec[j].bv_page), - fbio->bi_io_vec[j].bv_len)) - break; - if (j == vcnt) - continue; - mddev->resync_mismatches += r10_bio->sectors; - 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 - */ - tbio->bi_vcnt = vcnt; - tbio->bi_size = r10_bio->sectors << 9; - tbio->bi_idx = 0; - tbio->bi_phys_segments = 0; - tbio->bi_flags &= ~(BIO_POOL_MASK - 1); - tbio->bi_flags |= 1 << BIO_UPTODATE; - tbio->bi_next = NULL; - tbio->bi_rw = WRITE; - tbio->bi_private = r10_bio; - tbio->bi_sector = r10_bio->devs[i].addr; - - for (j=0; j < vcnt ; j++) { - tbio->bi_io_vec[j].bv_offset = 0; - tbio->bi_io_vec[j].bv_len = PAGE_SIZE; - - memcpy(page_address(tbio->bi_io_vec[j].bv_page), - page_address(fbio->bi_io_vec[j].bv_page), - PAGE_SIZE); - } - tbio->bi_end_io = end_sync_write; - - 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, tbio->bi_size >> 9); - - tbio->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 j, 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) - for (j = 0; j < vcnt; j++) - memcpy(page_address(tbio->bi_io_vec[j].bv_page), - page_address(fbio->bi_io_vec[j].bv_page), - PAGE_SIZE); - d = r10_bio->devs[i].devnum; - atomic_inc(&r10_bio->remaining); - md_sync_acct(conf->mirrors[d].replacement->bdev, - tbio->bi_size >> 9); - 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; - if (wbio->bi_end_io) { - atomic_inc(&conf->mirrors[d].rdev->nr_pending); - md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); - generic_make_request(wbio); - } - if (wbio2 && wbio2->bi_end_io) { - atomic_inc(&conf->mirrors[d].replacement->nr_pending); - md_sync_acct(conf->mirrors[d].replacement->bdev, - wbio2->bi_size >> 9); - 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(Unmerged, &rdev->flags) && - 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(Unmerged, &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, 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 + rdev->data_offset), - 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 + rdev->data_offset), - 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 + rdev->data_offset), - 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 void bi_complete(struct bio *bio, int error) -{ - complete((struct completion *)bio->bi_private); -} - -static int submit_bio_wait(int rw, struct bio *bio) -{ - struct completion event; - rw |= REQ_SYNC; - - init_completion(&event); - bio->bi_private = &event; - bio->bi_end_io = bi_complete; - submit_bio(rw, bio); - wait_for_completion(&event); - - return test_bit(BIO_UPTODATE, &bio->bi_flags); -} - -static int narrow_write_error(struct 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 = 1 << rdev->badblocks.shift; - 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); - md_trim_bio(wbio, sector - bio->bi_sector, sectors); - wbio->bi_sector = (r10_bio->devs[i].addr+ - rdev->data_offset+ - (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); - 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); - md_trim_bio(bio, - r10_bio->sector - bio->bi_sector, - max_sectors); - r10_bio->devs[slot].bio = bio; - r10_bio->devs[slot].rdev = rdev; - bio->bi_sector = r10_bio->devs[slot].addr - + rdev->data_offset; - 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_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 = (mbio->bi_size >> 9) - - sectors_handled; - r10_bio->state = 0; - set_bit(R10BIO_ReadError, - &r10_bio->state); - r10_bio->mddev = mddev; - r10_bio->sector = mbio->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 (test_bit(BIO_UPTODATE, - &r10_bio->devs[m].bio->bi_flags)) { - rdev_clear_badblocks( - rdev, - r10_bio->devs[m].addr, - r10_bio->sectors); - } 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 (test_bit(BIO_UPTODATE, - &r10_bio->devs[m].repl_bio->bi_flags)) { - rdev_clear_badblocks( - rdev, - r10_bio->devs[m].addr, - r10_bio->sectors); - } 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 { - 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); - rdev_dec_pending(rdev, conf->mddev); - } else if (bio != NULL && - !test_bit(BIO_UPTODATE, &bio->bi_flags)) { - 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); - rdev_dec_pending(rdev, conf->mddev); - } - } - if (test_bit(R10BIO_WriteError, - &r10_bio->state)) - close_write(r10_bio); - raid_end_bio_io(r10_bio); - } -} - -static void raid10d(struct mddev *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); - - 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_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->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, int go_faster) -{ - 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; - - if (!conf->r10buf_pool) - if (init_resync(conf)) - return 0; - - skipped: - max_sector = mddev->dev_sectors; - if (test_bit(MD_RECOVERY_SYNC, &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 (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->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->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 (chunks_skipped >= conf->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->near_copies < conf->raid_disks && - max_sector > (sector_nr | conf->chunk_mask)) - max_sector = (sector_nr | conf->chunk_mask) + 1; - /* - * If there is non-resync activity waiting for us then - * put in a delay to throttle resync. - */ - if (!go_faster && conf->nr_waiting) - msleep_interruptible(1000); - - /* 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->raid_disks; i++) { - int still_degraded; - struct r10bio *rb2; - sector_t sect; - int must_sync; - int any_working; - struct mirror_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); - 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 - */ - for (j=0; j<conf->raid_disks; j++) - if (conf->mirrors[j].rdev == NULL || - test_bit(Faulty, &conf->mirrors[j].rdev->flags)) { - still_degraded = 1; - break; - } - - must_sync = 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; - sector_t sector, first_bad; - int bad_sectors; - if (!conf->mirrors[d].rdev || - !test_bit(In_sync, &conf->mirrors[d].rdev->flags)) - continue; - /* This is where we read from */ - any_working = 1; - rdev = conf->mirrors[d].rdev; - 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_private = r10_bio; - bio->bi_end_io = end_sync_read; - bio->bi_rw = READ; - from_addr = r10_bio->devs[j].addr; - bio->bi_sector = from_addr + rdev->data_offset; - bio->bi_bdev = 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; - - rdev = mirror->rdev; - if (!test_bit(In_sync, &rdev->flags)) { - bio = r10_bio->devs[1].bio; - bio->bi_next = biolist; - biolist = bio; - bio->bi_private = r10_bio; - bio->bi_end_io = end_sync_write; - bio->bi_rw = WRITE; - bio->bi_sector = to_addr - + rdev->data_offset; - bio->bi_bdev = rdev->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; - rdev = mirror->replacement; - /* Note: if rdev != NULL, then bio - * cannot be NULL as r10buf_pool_alloc will - * have allocated it. - * So the second test here is pointless. - * But it keeps semantic-checkers happy, and - * this comment keeps human reviewers - * happy. - */ - if (rdev == NULL || bio == NULL || - test_bit(Faulty, &rdev->flags)) - break; - bio->bi_next = biolist; - biolist = bio; - bio->bi_private = r10_bio; - bio->bi_end_io = end_sync_write; - bio->bi_rw = WRITE; - bio->bi_sector = to_addr + rdev->data_offset; - bio->bi_bdev = rdev->bdev; - atomic_inc(&r10_bio->remaining); - break; - } - if (j == conf->copies) { - /* Cannot recover, so abort the recovery or - * record a bad block */ - put_buf(r10_bio); - if (rb2) - atomic_dec(&rb2->remaining); - r10_bio = rb2; - 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 (!test_bit(In_sync, - &mirror->rdev->flags) - && !rdev_set_badblocks( - mirror->rdev, - r10_bio->devs[k].addr, - max_sync, 0)) - any_working = 0; - if (mirror->replacement && - !rdev_set_badblocks( - mirror->replacement, - r10_bio->devs[k].addr, - max_sync, 0)) - any_working = 0; - } - if (!any_working) { - if (!test_and_set_bit(MD_RECOVERY_INTR, - &mddev->recovery)) - printk(KERN_INFO "md/raid10:%s: insufficient " - "working devices for recovery.\n", - mdname(mddev)); - mirror->recovery_disabled - = mddev->recovery_disabled; - } - break; - } - } - 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; - - bitmap_cond_end_sync(mddev->bitmap, sector_nr); - - if (!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 = mempool_alloc(conf->r10buf_pool, GFP_NOIO); - - 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 | conf->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; - - 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_end_io = NULL; - clear_bit(BIO_UPTODATE, &bio->bi_flags); - if (conf->mirrors[d].rdev == NULL || - test_bit(Faulty, &conf->mirrors[d].rdev->flags)) - continue; - sector = r10_bio->devs[i].addr; - if (is_badblock(conf->mirrors[d].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 = max_sync; - continue; - } - } - atomic_inc(&conf->mirrors[d].rdev->nr_pending); - atomic_inc(&r10_bio->remaining); - bio->bi_next = biolist; - biolist = bio; - bio->bi_private = r10_bio; - bio->bi_end_io = end_sync_read; - bio->bi_rw = READ; - bio->bi_sector = sector + - conf->mirrors[d].rdev->data_offset; - bio->bi_bdev = conf->mirrors[d].rdev->bdev; - count++; - - if (conf->mirrors[d].replacement == NULL || - test_bit(Faulty, - &conf->mirrors[d].replacement->flags)) - continue; - - /* Need to set up for writing to the replacement */ - bio = r10_bio->devs[i].repl_bio; - clear_bit(BIO_UPTODATE, &bio->bi_flags); - - sector = r10_bio->devs[i].addr; - atomic_inc(&conf->mirrors[d].rdev->nr_pending); - bio->bi_next = biolist; - biolist = bio; - bio->bi_private = r10_bio; - bio->bi_end_io = end_sync_write; - bio->bi_rw = WRITE; - bio->bi_sector = sector + - conf->mirrors[d].replacement->data_offset; - bio->bi_bdev = conf->mirrors[d].replacement->bdev; - count++; - } - - 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; - } - } - - for (bio = biolist; bio ; bio=bio->bi_next) { - - bio->bi_flags &= ~(BIO_POOL_MASK - 1); - if (bio->bi_end_io) - bio->bi_flags |= 1 << BIO_UPTODATE; - bio->bi_vcnt = 0; - bio->bi_idx = 0; - bio->bi_phys_segments = 0; - bio->bi_size = 0; - } - - 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 bio *bio2; - page = bio->bi_io_vec[bio->bi_vcnt].bv_page; - if (bio_add_page(bio, page, len, 0)) - continue; - - /* stop here */ - bio->bi_io_vec[bio->bi_vcnt].bv_page = page; - for (bio2 = biolist; - bio2 && bio2 != bio; - bio2 = bio2->bi_next) { - /* remove last page from this bio */ - bio2->bi_vcnt--; - bio2->bi_size -= len; - bio2->bi_flags &= ~(1<< BIO_SEG_VALID); - } - goto bio_full; - } - nr_sectors += len>>9; - sector_nr += len>>9; - } while (biolist->bi_vcnt < RESYNC_PAGES); - bio_full: - r10_bio->sectors = nr_sectors; - - while (biolist) { - bio = biolist; - biolist = biolist->bi_next; - - bio->bi_next = NULL; - r10_bio = bio->bi_private; - r10_bio->sectors = nr_sectors; - - if (bio->bi_end_io == end_sync_read) { - md_sync_acct(bio->bi_bdev, nr_sectors); - generic_make_request(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 = conf->raid_disks; - if (!sectors) - sectors = conf->dev_sectors; - - size = sectors >> conf->chunk_shift; - sector_div(size, conf->far_copies); - size = size * raid_disks; - sector_div(size, conf->near_copies); - - return size << conf->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->chunk_shift; - sector_div(size, conf->far_copies); - size = size * conf->raid_disks; - sector_div(size, conf->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->raid_disks); - - conf->dev_sectors = size << conf->chunk_shift; - - if (conf->far_offset) - conf->stride = 1 << conf->chunk_shift; - else { - sector_div(size, conf->far_copies); - conf->stride = size << conf->chunk_shift; - } -} - -static struct r10conf *setup_conf(struct mddev *mddev) -{ - struct r10conf *conf = NULL; - int nc, fc, fo; - int err = -EINVAL; - - if (mddev->new_chunk_sectors < (PAGE_SIZE >> 9) || - !is_power_of_2(mddev->new_chunk_sectors)) { - printk(KERN_ERR "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; - } - - nc = mddev->new_layout & 255; - fc = (mddev->new_layout >> 8) & 255; - fo = mddev->new_layout & (1<<16); - - if ((nc*fc) <2 || (nc*fc) > mddev->raid_disks || - (mddev->new_layout >> 17)) { - printk(KERN_ERR "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; - - conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, - GFP_KERNEL); - if (!conf->mirrors) - goto out; - - conf->tmppage = alloc_page(GFP_KERNEL); - if (!conf->tmppage) - goto out; - - - conf->raid_disks = mddev->raid_disks; - conf->near_copies = nc; - conf->far_copies = fc; - conf->copies = nc*fc; - conf->far_offset = fo; - conf->chunk_mask = mddev->new_chunk_sectors - 1; - conf->chunk_shift = ffz(~mddev->new_chunk_sectors); - - conf->r10bio_pool = mempool_create(NR_RAID10_BIOS, r10bio_pool_alloc, - r10bio_pool_free, conf); - if (!conf->r10bio_pool) - goto out; - - calc_sectors(conf, mddev->dev_sectors); - - spin_lock_init(&conf->device_lock); - INIT_LIST_HEAD(&conf->retry_list); - - spin_lock_init(&conf->resync_lock); - init_waitqueue_head(&conf->wait_barrier); - - conf->thread = md_register_thread(raid10d, mddev, NULL); - if (!conf->thread) - goto out; - - conf->mddev = mddev; - return conf; - - out: - printk(KERN_ERR "md/raid10:%s: couldn't allocate memory.\n", - mdname(mddev)); - if (conf) { - if (conf->r10bio_pool) - mempool_destroy(conf->r10bio_pool); - kfree(conf->mirrors); - safe_put_page(conf->tmppage); - kfree(conf); - } - return ERR_PTR(err); -} - -static int run(struct mddev *mddev) -{ - struct r10conf *conf; - int i, disk_idx, chunk_size; - struct mirror_info *disk; - struct md_rdev *rdev; - sector_t size; - - /* - * copy the already verified devices into our private RAID10 - * bookkeeping area. [whatever we allocate in run(), - * should be freed in stop()] - */ - - 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; - - mddev->thread = conf->thread; - conf->thread = NULL; - - chunk_size = mddev->chunk_sectors << 9; - blk_queue_io_min(mddev->queue, chunk_size); - if (conf->raid_disks % conf->near_copies) - blk_queue_io_opt(mddev->queue, chunk_size * conf->raid_disks); - else - blk_queue_io_opt(mddev->queue, chunk_size * - (conf->raid_disks / conf->near_copies)); - - rdev_for_each(rdev, mddev) { - struct request_queue *q; - disk_idx = rdev->raid_disk; - if (disk_idx >= conf->raid_disks - || disk_idx < 0) - 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; - } - q = bdev_get_queue(rdev->bdev); - if (q->merge_bvec_fn) - mddev->merge_check_needed = 1; - - disk_stack_limits(mddev->gendisk, rdev->bdev, - rdev->data_offset << 9); - - disk->head_position = 0; - } - /* need to check that every block has at least one working mirror */ - if (!enough(conf, -1)) { - printk(KERN_ERR "md/raid10:%s: not enough operational mirrors.\n", - mdname(mddev)); - goto out_free_conf; - } - - mddev->degraded = 0; - for (i = 0; i < conf->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) - conf->fullsync = 1; - } - disk->recovery_disabled = mddev->recovery_disabled - 1; - } - - if (mddev->recovery_cp != MaxSector) - printk(KERN_NOTICE "md/raid10:%s: not clean" - " -- starting background reconstruction\n", - mdname(mddev)); - printk(KERN_INFO - "md/raid10:%s: active with %d out of %d devices\n", - mdname(mddev), conf->raid_disks - mddev->degraded, - conf->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; - - mddev->queue->backing_dev_info.congested_fn = raid10_congested; - mddev->queue->backing_dev_info.congested_data = mddev; - - /* Calculate max read-ahead size. - * We need to readahead at least twice a whole stripe.... - * maybe... - */ - { - int stripe = conf->raid_disks * - ((mddev->chunk_sectors << 9) / PAGE_SIZE); - stripe /= conf->near_copies; - if (mddev->queue->backing_dev_info.ra_pages < 2* stripe) - mddev->queue->backing_dev_info.ra_pages = 2* stripe; - } - - blk_queue_merge_bvec(mddev->queue, raid10_mergeable_bvec); - - if (md_integrity_register(mddev)) - goto out_free_conf; - - return 0; - -out_free_conf: - md_unregister_thread(&mddev->thread); - if (conf->r10bio_pool) - mempool_destroy(conf->r10bio_pool); - safe_put_page(conf->tmppage); - kfree(conf->mirrors); - kfree(conf); - mddev->private = NULL; -out: - return -EIO; -} - -static int stop(struct mddev *mddev) -{ - struct r10conf *conf = mddev->private; - - raise_barrier(conf, 0); - lower_barrier(conf); - - md_unregister_thread(&mddev->thread); - blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ - if (conf->r10bio_pool) - mempool_destroy(conf->r10bio_pool); - kfree(conf->mirrors); - kfree(conf); - mddev->private = NULL; - return 0; -} - -static void raid10_quiesce(struct mddev *mddev, int state) -{ - struct r10conf *conf = mddev->private; - - switch(state) { - case 1: - raise_barrier(conf, 0); - break; - case 0: - lower_barrier(conf); - break; - } -} - -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 (conf->far_copies > 1 && !conf->far_offset) - return -EINVAL; - - oldsize = raid10_size(mddev, 0, 0); - size = raid10_size(mddev, sectors, 0); - md_set_array_sectors(mddev, size); - if (mddev->array_sectors > size) - return -EINVAL; - set_capacity(mddev->gendisk, mddev->array_sectors); - revalidate_disk(mddev->gendisk); - 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) -{ - struct md_rdev *rdev; - struct r10conf *conf; - - if (mddev->degraded > 0) { - printk(KERN_ERR "md/raid10:%s: Error: degraded raid0!\n", - mdname(mddev)); - return ERR_PTR(-EINVAL); - } - - /* 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; - - 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; - conf->barrier = 1; - } - - 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) { - printk(KERN_ERR "md/raid10:%s: cannot takeover raid 0" - " with more than one zone.\n", - mdname(mddev)); - return ERR_PTR(-EINVAL); - } - return raid10_takeover_raid0(mddev); - } - return ERR_PTR(-EINVAL); -} - -static struct md_personality raid10_personality = -{ - .name = "raid10", - .level = 10, - .owner = THIS_MODULE, - .make_request = make_request, - .run = run, - .stop = stop, - .status = status, - .error_handler = error, - .hot_add_disk = raid10_add_disk, - .hot_remove_disk= raid10_remove_disk, - .spare_active = raid10_spare_active, - .sync_request = sync_request, - .quiesce = raid10_quiesce, - .size = raid10_size, - .resize = raid10_resize, - .takeover = raid10_takeover, -}; - -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"); - -module_param(max_queued_requests, int, S_IRUGO|S_IWUSR); |