| /* |
| * 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/seq_file.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 |
| |
| static void allow_barrier(conf_t *conf); |
| static void lower_barrier(conf_t *conf); |
| |
| static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data) |
| { |
| conf_t *conf = data; |
| int size = offsetof(struct r10bio_s, 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) |
| { |
| conf_t *conf = data; |
| struct page *page; |
| r10bio_t *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; |
| } |
| /* |
| * Allocate RESYNC_PAGES data pages and attach them |
| * where needed. |
| */ |
| for (j = 0 ; j < nalloc; j++) { |
| bio = r10_bio->devs[j].bio; |
| for (i = 0; i < RESYNC_PAGES; i++) { |
| page = alloc_page(gfp_flags); |
| if (unlikely(!page)) |
| goto out_free_pages; |
| |
| bio->bi_io_vec[i].bv_page = page; |
| } |
| } |
| |
| 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); |
| r10bio_pool_free(r10_bio, conf); |
| return NULL; |
| } |
| |
| static void r10buf_pool_free(void *__r10_bio, void *data) |
| { |
| int i; |
| conf_t *conf = data; |
| r10bio_t *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); |
| } |
| } |
| r10bio_pool_free(r10bio, conf); |
| } |
| |
| static void put_all_bios(conf_t *conf, r10bio_t *r10_bio) |
| { |
| int i; |
| |
| for (i = 0; i < conf->copies; i++) { |
| struct bio **bio = & r10_bio->devs[i].bio; |
| if (*bio && *bio != IO_BLOCKED) |
| bio_put(*bio); |
| *bio = NULL; |
| } |
| } |
| |
| static void free_r10bio(r10bio_t *r10_bio) |
| { |
| conf_t *conf = r10_bio->mddev->private; |
| |
| /* |
| * Wake up any possible resync thread that waits for the device |
| * to go idle. |
| */ |
| allow_barrier(conf); |
| |
| put_all_bios(conf, r10_bio); |
| mempool_free(r10_bio, conf->r10bio_pool); |
| } |
| |
| static void put_buf(r10bio_t *r10_bio) |
| { |
| conf_t *conf = r10_bio->mddev->private; |
| |
| mempool_free(r10_bio, conf->r10buf_pool); |
| |
| lower_barrier(conf); |
| } |
| |
| static void reschedule_retry(r10bio_t *r10_bio) |
| { |
| unsigned long flags; |
| mddev_t *mddev = r10_bio->mddev; |
| conf_t *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(r10bio_t *r10_bio) |
| { |
| struct bio *bio = r10_bio->master_bio; |
| |
| bio_endio(bio, |
| test_bit(R10BIO_Uptodate, &r10_bio->state) ? 0 : -EIO); |
| free_r10bio(r10_bio); |
| } |
| |
| /* |
| * Update disk head position estimator based on IRQ completion info. |
| */ |
| static inline void update_head_pos(int slot, r10bio_t *r10_bio) |
| { |
| conf_t *conf = r10_bio->mddev->private; |
| |
| conf->mirrors[r10_bio->devs[slot].devnum].head_position = |
| r10_bio->devs[slot].addr + (r10_bio->sectors); |
| } |
| |
| static void raid10_end_read_request(struct bio *bio, int error) |
| { |
| int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| r10bio_t *r10_bio = bio->bi_private; |
| int slot, dev; |
| conf_t *conf = r10_bio->mddev->private; |
| |
| |
| slot = r10_bio->read_slot; |
| dev = r10_bio->devs[slot].devnum; |
| /* |
| * 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); |
| raid_end_bio_io(r10_bio); |
| rdev_dec_pending(conf->mirrors[dev].rdev, conf->mddev); |
| } else { |
| /* |
| * oops, read error - keep the refcount on the rdev |
| */ |
| char b[BDEVNAME_SIZE]; |
| if (printk_ratelimit()) |
| printk(KERN_ERR "md/raid10:%s: %s: rescheduling sector %llu\n", |
| mdname(conf->mddev), |
| bdevname(conf->mirrors[dev].rdev->bdev,b), (unsigned long long)r10_bio->sector); |
| reschedule_retry(r10_bio); |
| } |
| } |
| |
| static void raid10_end_write_request(struct bio *bio, int error) |
| { |
| int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| r10bio_t *r10_bio = bio->bi_private; |
| int slot, dev; |
| conf_t *conf = r10_bio->mddev->private; |
| |
| for (slot = 0; slot < conf->copies; slot++) |
| if (r10_bio->devs[slot].bio == bio) |
| break; |
| dev = r10_bio->devs[slot].devnum; |
| |
| /* |
| * this branch is our 'one mirror IO has finished' event handler: |
| */ |
| if (!uptodate) { |
| md_error(r10_bio->mddev, conf->mirrors[dev].rdev); |
| /* an I/O failed, we can't clear the bitmap */ |
| set_bit(R10BIO_Degraded, &r10_bio->state); |
| } 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. |
| */ |
| set_bit(R10BIO_Uptodate, &r10_bio->state); |
| |
| update_head_pos(slot, r10_bio); |
| |
| /* |
| * |
| * Let's see if all mirrored write operations have finished |
| * already. |
| */ |
| if (atomic_dec_and_test(&r10_bio->remaining)) { |
| /* 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); |
| raid_end_bio_io(r10_bio); |
| } |
| |
| 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(conf_t *conf, r10bio_t *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(conf_t *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 |
| * If near_copies == raid_disk, there are no striping issues, |
| * but in that case, the function isn't called at all. |
| */ |
| static int raid10_mergeable_bvec(struct request_queue *q, |
| struct bvec_merge_data *bvm, |
| struct bio_vec *biovec) |
| { |
| mddev_t *mddev = q->queuedata; |
| 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; |
| |
| max = (chunk_sectors - ((sector & (chunk_sectors - 1)) + bio_sectors)) << 9; |
| if (max < 0) max = 0; /* bio_add cannot handle a negative return */ |
| if (max <= biovec->bv_len && bio_sectors == 0) |
| return biovec->bv_len; |
| else |
| 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 int read_balance(conf_t *conf, r10bio_t *r10_bio) |
| { |
| const sector_t this_sector = r10_bio->sector; |
| int disk, slot; |
| const int sectors = r10_bio->sectors; |
| sector_t new_distance, best_dist; |
| mdk_rdev_t *rdev; |
| int do_balance; |
| int best_slot; |
| |
| raid10_find_phys(conf, r10_bio); |
| rcu_read_lock(); |
| retry: |
| best_slot = -1; |
| best_dist = MaxSector; |
| 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++) { |
| if (r10_bio->devs[slot].bio == IO_BLOCKED) |
| continue; |
| disk = r10_bio->devs[slot].devnum; |
| rdev = rcu_dereference(conf->mirrors[disk].rdev); |
| if (rdev == NULL) |
| continue; |
| if (!test_bit(In_sync, &rdev->flags)) |
| continue; |
| |
| 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; |
| } |
| } |
| if (slot == conf->copies) |
| slot = best_slot; |
| |
| if (slot >= 0) { |
| disk = r10_bio->devs[slot].devnum; |
| rdev = rcu_dereference(conf->mirrors[disk].rdev); |
| if (!rdev) |
| goto retry; |
| atomic_inc(&rdev->nr_pending); |
| if (test_bit(Faulty, &rdev->flags)) { |
| /* Cannot risk returning a device that failed |
| * before we inc'ed nr_pending |
| */ |
| rdev_dec_pending(rdev, conf->mddev); |
| goto retry; |
| } |
| r10_bio->read_slot = slot; |
| } else |
| disk = -1; |
| rcu_read_unlock(); |
| |
| return disk; |
| } |
| |
| static int raid10_congested(void *data, int bits) |
| { |
| mddev_t *mddev = data; |
| conf_t *conf = mddev->private; |
| int i, ret = 0; |
| |
| if (mddev_congested(mddev, bits)) |
| return 1; |
| rcu_read_lock(); |
| for (i = 0; i < conf->raid_disks && ret == 0; i++) { |
| mdk_rdev_t *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(conf_t *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); |
| spin_unlock_irq(&conf->device_lock); |
| /* flush any pending bitmap writes to disk |
| * before proceeding w/ I/O */ |
| bitmap_unplug(conf->mddev->bitmap); |
| |
| 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(conf_t *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(conf_t *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(conf_t *conf) |
| { |
| spin_lock_irq(&conf->resync_lock); |
| if (conf->barrier) { |
| conf->nr_waiting++; |
| wait_event_lock_irq(conf->wait_barrier, !conf->barrier, |
| conf->resync_lock, |
| ); |
| conf->nr_waiting--; |
| } |
| conf->nr_pending++; |
| spin_unlock_irq(&conf->resync_lock); |
| } |
| |
| static void allow_barrier(conf_t *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(conf_t *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(conf_t *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 int make_request(mddev_t *mddev, struct bio * bio) |
| { |
| conf_t *conf = mddev->private; |
| mirror_info_t *mirror; |
| r10bio_t *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; |
| mdk_rdev_t *blocked_rdev; |
| int plugged; |
| |
| if (unlikely(bio->bi_rw & REQ_FLUSH)) { |
| md_flush_request(mddev, bio); |
| return 0; |
| } |
| |
| /* 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); |
| |
| if (make_request(mddev, &bp->bio1)) |
| generic_make_request(&bp->bio1); |
| if (make_request(mddev, &bp->bio2)) |
| generic_make_request(&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 0; |
| 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 0; |
| } |
| |
| 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; |
| |
| if (rw == READ) { |
| /* |
| * read balancing logic: |
| */ |
| int disk = read_balance(conf, r10_bio); |
| int slot = r10_bio->read_slot; |
| if (disk < 0) { |
| raid_end_bio_io(r10_bio); |
| return 0; |
| } |
| mirror = conf->mirrors + disk; |
| |
| read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); |
| |
| r10_bio->devs[slot].bio = read_bio; |
| |
| read_bio->bi_sector = r10_bio->devs[slot].addr + |
| mirror->rdev->data_offset; |
| read_bio->bi_bdev = mirror->rdev->bdev; |
| read_bio->bi_end_io = raid10_end_read_request; |
| read_bio->bi_rw = READ | do_sync; |
| read_bio->bi_private = r10_bio; |
| |
| generic_make_request(read_bio); |
| return 0; |
| } |
| |
| /* |
| * WRITE: |
| */ |
| /* first select target devices under rcu_lock and |
| * inc refcount on their rdev. Record them by setting |
| * bios[x] to bio |
| */ |
| plugged = mddev_check_plugged(mddev); |
| |
| raid10_find_phys(conf, r10_bio); |
| retry_write: |
| blocked_rdev = NULL; |
| rcu_read_lock(); |
| for (i = 0; i < conf->copies; i++) { |
| int d = r10_bio->devs[i].devnum; |
| mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[d].rdev); |
| if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) { |
| atomic_inc(&rdev->nr_pending); |
| blocked_rdev = rdev; |
| break; |
| } |
| if (rdev && !test_bit(Faulty, &rdev->flags)) { |
| atomic_inc(&rdev->nr_pending); |
| r10_bio->devs[i].bio = bio; |
| } else { |
| r10_bio->devs[i].bio = NULL; |
| set_bit(R10BIO_Degraded, &r10_bio->state); |
| } |
| } |
| 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); |
| } |
| allow_barrier(conf); |
| md_wait_for_blocked_rdev(blocked_rdev, mddev); |
| wait_barrier(conf); |
| goto retry_write; |
| } |
| |
| atomic_set(&r10_bio->remaining, 1); |
| bitmap_startwrite(mddev->bitmap, bio->bi_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); |
| 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); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| } |
| |
| if (atomic_dec_and_test(&r10_bio->remaining)) { |
| /* This matches the end of raid10_end_write_request() */ |
| bitmap_endwrite(r10_bio->mddev->bitmap, r10_bio->sector, |
| r10_bio->sectors, |
| !test_bit(R10BIO_Degraded, &r10_bio->state), |
| 0); |
| md_write_end(mddev); |
| raid_end_bio_io(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); |
| return 0; |
| } |
| |
| static void status(struct seq_file *seq, mddev_t *mddev) |
| { |
| conf_t *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, "]"); |
| } |
| |
| static void error(mddev_t *mddev, mdk_rdev_t *rdev) |
| { |
| char b[BDEVNAME_SIZE]; |
| conf_t *conf = mddev->private; |
| |
| /* |
| * If it is not operational, then we have already marked it as dead |
| * else if it is the last working disks, ignore the error, let the |
| * next level up know. |
| * else mark the drive as failed |
| */ |
| if (test_bit(In_sync, &rdev->flags) |
| && conf->raid_disks-mddev->degraded == 1) |
| /* |
| * Don't fail the drive, just return an IO error. |
| * The test should really be more sophisticated than |
| * "working_disks == 1", but it isn't critical, and |
| * can wait until we do more sophisticated "is the drive |
| * really dead" tests... |
| */ |
| 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(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(conf_t *conf) |
| { |
| int i; |
| mirror_info_t *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(conf_t *conf) |
| { |
| wait_barrier(conf); |
| allow_barrier(conf); |
| |
| mempool_destroy(conf->r10buf_pool); |
| conf->r10buf_pool = NULL; |
| } |
| |
| /* check if there are enough drives for |
| * every block to appear on atleast one |
| */ |
| static int enough(conf_t *conf) |
| { |
| int first = 0; |
| |
| do { |
| int n = conf->copies; |
| int cnt = 0; |
| while (n--) { |
| if (conf->mirrors[first].rdev) |
| cnt++; |
| first = (first+1) % conf->raid_disks; |
| } |
| if (cnt == 0) |
| return 0; |
| } while (first != 0); |
| return 1; |
| } |
| |
| static int raid10_spare_active(mddev_t *mddev) |
| { |
| int i; |
| conf_t *conf = mddev->private; |
| mirror_info_t *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->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(mddev_t *mddev, mdk_rdev_t *rdev) |
| { |
| conf_t *conf = mddev->private; |
| int err = -EEXIST; |
| int mirror; |
| mirror_info_t *p; |
| int first = 0; |
| int last = conf->raid_disks - 1; |
| |
| if (mddev->recovery_cp < MaxSector) |
| /* only hot-add to in-sync arrays, as recovery is |
| * very different from resync |
| */ |
| return -EBUSY; |
| if (!enough(conf)) |
| return -EINVAL; |
| |
| if (rdev->raid_disk >= 0) |
| first = last = rdev->raid_disk; |
| |
| if (rdev->saved_raid_disk >= 0 && |
| 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++) |
| if ( !(p=conf->mirrors+mirror)->rdev) { |
| |
| disk_stack_limits(mddev->gendisk, rdev->bdev, |
| rdev->data_offset << 9); |
| /* as we don't honour merge_bvec_fn, we must |
| * never risk violating it, so limit |
| * ->max_segments to one lying with a single |
| * page, as a one page request is never in |
| * violation. |
| */ |
| if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { |
| blk_queue_max_segments(mddev->queue, 1); |
| blk_queue_segment_boundary(mddev->queue, |
| PAGE_CACHE_SIZE - 1); |
| } |
| |
| p->head_position = 0; |
| rdev->raid_disk = mirror; |
| err = 0; |
| if (rdev->saved_raid_disk != mirror) |
| conf->fullsync = 1; |
| rcu_assign_pointer(p->rdev, rdev); |
| break; |
| } |
| |
| md_integrity_add_rdev(rdev, mddev); |
| print_conf(conf); |
| return err; |
| } |
| |
| static int raid10_remove_disk(mddev_t *mddev, int number) |
| { |
| conf_t *conf = mddev->private; |
| int err = 0; |
| mdk_rdev_t *rdev; |
| mirror_info_t *p = conf->mirrors+ number; |
| |
| print_conf(conf); |
| rdev = p->rdev; |
| if (rdev) { |
| if (test_bit(In_sync, &rdev->flags) || |
| atomic_read(&rdev->nr_pending)) { |
| err = -EBUSY; |
| goto abort; |
| } |
| /* Only remove faulty devices in recovery |
| * is not possible. |
| */ |
| if (!test_bit(Faulty, &rdev->flags) && |
| enough(conf)) { |
| err = -EBUSY; |
| goto abort; |
| } |
| p->rdev = NULL; |
| synchronize_rcu(); |
| if (atomic_read(&rdev->nr_pending)) { |
| /* lost the race, try later */ |
| err = -EBUSY; |
| p->rdev = rdev; |
| goto abort; |
| } |
| err = md_integrity_register(mddev); |
| } |
| abort: |
| |
| print_conf(conf); |
| return err; |
| } |
| |
| |
| static void end_sync_read(struct bio *bio, int error) |
| { |
| r10bio_t *r10_bio = bio->bi_private; |
| conf_t *conf = r10_bio->mddev->private; |
| int i,d; |
| |
| for (i=0; i<conf->copies; i++) |
| if (r10_bio->devs[i].bio == bio) |
| break; |
| BUG_ON(i == conf->copies); |
| update_head_pos(i, r10_bio); |
| d = r10_bio->devs[i].devnum; |
| |
| if (test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| set_bit(R10BIO_Uptodate, &r10_bio->state); |
| else { |
| atomic_add(r10_bio->sectors, |
| &conf->mirrors[d].rdev->corrected_errors); |
| if (!test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery)) |
| md_error(r10_bio->mddev, |
| conf->mirrors[d].rdev); |
| } |
| |
| /* 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_write(struct bio *bio, int error) |
| { |
| int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| r10bio_t *r10_bio = bio->bi_private; |
| mddev_t *mddev = r10_bio->mddev; |
| conf_t *conf = mddev->private; |
| int i,d; |
| |
| for (i = 0; i < conf->copies; i++) |
| if (r10_bio->devs[i].bio == bio) |
| break; |
| d = r10_bio->devs[i].devnum; |
| |
| if (!uptodate) |
| md_error(mddev, conf->mirrors[d].rdev); |
| |
| update_head_pos(i, r10_bio); |
| |
| rdev_dec_pending(conf->mirrors[d].rdev, 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; |
| put_buf(r10_bio); |
| md_done_sync(mddev, s, 1); |
| break; |
| } else { |
| r10bio_t *r10_bio2 = (r10bio_t *)r10_bio->master_bio; |
| put_buf(r10_bio); |
| r10_bio = r10_bio2; |
| } |
| } |
| } |
| |
| /* |
| * 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(mddev_t *mddev, r10bio_t *r10_bio) |
| { |
| conf_t *conf = mddev->private; |
| int i, first; |
| struct bio *tbio, *fbio; |
| |
| 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; |
| |
| /* now find blocks with errors */ |
| for (i=0 ; i < conf->copies ; i++) { |
| int j, d; |
| int vcnt = r10_bio->sectors >> (PAGE_SHIFT-9); |
| |
| 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), |
| PAGE_SIZE)) |
| 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 |
| * 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); |
| } |
| |
| 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 recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio) |
| { |
| conf_t *conf = mddev->private; |
| int i, d; |
| struct bio *bio, *wbio; |
| |
| |
| /* move the pages across to the second bio |
| * and submit the write request |
| */ |
| bio = r10_bio->devs[0].bio; |
| wbio = r10_bio->devs[1].bio; |
| for (i=0; i < wbio->bi_vcnt; i++) { |
| struct page *p = bio->bi_io_vec[i].bv_page; |
| bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page; |
| wbio->bi_io_vec[i].bv_page = p; |
| } |
| d = r10_bio->devs[1].devnum; |
| |
| atomic_inc(&conf->mirrors[d].rdev->nr_pending); |
| md_sync_acct(conf->mirrors[d].rdev->bdev, wbio->bi_size >> 9); |
| if (test_bit(R10BIO_Uptodate, &r10_bio->state)) |
| generic_make_request(wbio); |
| else |
| bio_endio(wbio, -EIO); |
| } |
| |
| |
| /* |
| * 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(mddev_t *mddev, mdk_rdev_t *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); |
| } |
| |
| /* |
| * 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(conf_t *conf, mddev_t *mddev, r10bio_t *r10_bio) |
| { |
| int sect = 0; /* Offset from r10_bio->sector */ |
| int sectors = r10_bio->sectors; |
| mdk_rdev_t*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); |
| 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 { |
| d = r10_bio->devs[sl].devnum; |
| rdev = rcu_dereference(conf->mirrors[d].rdev); |
| if (rdev && |
| test_bit(In_sync, &rdev->flags)) { |
| 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 -- bye bye array */ |
| int dn = r10_bio->devs[r10_bio->read_slot].devnum; |
| md_error(mddev, conf->mirrors[dn].rdev); |
| break; |
| } |
| |
| start = sl; |
| /* write it back and re-read */ |
| rcu_read_lock(); |
| while (sl != r10_bio->read_slot) { |
| char b[BDEVNAME_SIZE]; |
| |
| if (sl==0) |
| sl = conf->copies; |
| sl--; |
| d = r10_bio->devs[sl].devnum; |
| rdev = rcu_dereference(conf->mirrors[d].rdev); |
| if (rdev && |
| test_bit(In_sync, &rdev->flags)) { |
| atomic_inc(&rdev->nr_pending); |
| rcu_read_unlock(); |
| atomic_add(s, &rdev->corrected_errors); |
| if (sync_page_io(rdev, |
| r10_bio->devs[sl].addr + |
| sect, |
| s<<9, conf->tmppage, WRITE, false) |
| == 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)); |
| md_error(mddev, rdev); |
| } |
| rdev_dec_pending(rdev, mddev); |
| rcu_read_lock(); |
| } |
| } |
| sl = start; |
| while (sl != r10_bio->read_slot) { |
| |
| if (sl==0) |
| sl = conf->copies; |
| sl--; |
| d = r10_bio->devs[sl].devnum; |
| rdev = rcu_dereference(conf->mirrors[d].rdev); |
| if (rdev && |
| test_bit(In_sync, &rdev->flags)) { |
| char b[BDEVNAME_SIZE]; |
| atomic_inc(&rdev->nr_pending); |
| rcu_read_unlock(); |
| if (sync_page_io(rdev, |
| r10_bio->devs[sl].addr + |
| sect, |
| s<<9, conf->tmppage, |
| READ, false) == 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)); |
| |
| md_error(mddev, rdev); |
| } else { |
| 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)); |
| } |
| |
| rdev_dec_pending(rdev, mddev); |
| rcu_read_lock(); |
| } |
| } |
| rcu_read_unlock(); |
| |
| sectors -= s; |
| sect += s; |
| } |
| } |
| |
| static void raid10d(mddev_t *mddev) |
| { |
| r10bio_t *r10_bio; |
| struct bio *bio; |
| unsigned long flags; |
| conf_t *conf = mddev->private; |
| struct list_head *head = &conf->retry_list; |
| mdk_rdev_t *rdev; |
| struct blk_plug plug; |
| |
| md_check_recovery(mddev); |
| |
| blk_start_plug(&plug); |
| for (;;) { |
| char b[BDEVNAME_SIZE]; |
| |
| 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, r10bio_t, 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_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 { |
| int slot = r10_bio->read_slot; |
| int mirror = r10_bio->devs[slot].devnum; |
| /* we got a read error. Maybe the drive is bad. Maybe just |
| * the block and we can fix it. |
| * We freeze all other IO, and try reading the block from |
| * other devices. When we find one, we re-write |
| * and check it that fixes the read error. |
| * This is all done synchronously while the array is |
| * frozen. |
| */ |
| if (mddev->ro == 0) { |
| freeze_array(conf); |
| fix_read_error(conf, mddev, r10_bio); |
| unfreeze_array(conf); |
| } |
| rdev_dec_pending(conf->mirrors[mirror].rdev, mddev); |
| |
| bio = r10_bio->devs[slot].bio; |
| r10_bio->devs[slot].bio = |
| mddev->ro ? IO_BLOCKED : NULL; |
| mirror = read_balance(conf, r10_bio); |
| if (mirror == -1) { |
| printk(KERN_ALERT "md/raid10:%s: %s: unrecoverable I/O" |
| " read error for block %llu\n", |
| mdname(mddev), |
| bdevname(bio->bi_bdev,b), |
| (unsigned long long)r10_bio->sector); |
| raid_end_bio_io(r10_bio); |
| bio_put(bio); |
| } else { |
| const unsigned long do_sync = (r10_bio->master_bio->bi_rw & REQ_SYNC); |
| bio_put(bio); |
| slot = r10_bio->read_slot; |
| rdev = conf->mirrors[mirror].rdev; |
| if (printk_ratelimit()) |
| printk(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); |
| r10_bio->devs[slot].bio = bio; |
| 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; |
| generic_make_request(bio); |
| } |
| } |
| cond_resched(); |
| } |
| blk_finish_plug(&plug); |
| } |
| |
| |
| static int init_resync(conf_t *conf) |
| { |
| int buffs; |
| |
| buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; |
| BUG_ON(conf->r10buf_pool); |
| 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(mddev_t *mddev, sector_t sector_nr, |
| int *skipped, int go_faster) |
| { |
| conf_t *conf = mddev->private; |
| r10bio_t *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 */ |
| 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, k; |
| r10_bio = NULL; |
| |
| for (i=0 ; i<conf->raid_disks; i++) { |
| int still_degraded; |
| r10bio_t *rb2; |
| sector_t sect; |
| int must_sync; |
| |
| if (conf->mirrors[i].rdev == NULL || |
| test_bit(In_sync, &conf->mirrors[i].rdev->flags)) |
| continue; |
| |
| still_degraded = 0; |
| /* want to reconstruct this device */ |
| rb2 = r10_bio; |
| sect = raid10_find_virt(conf, sector_nr, i); |
| /* Unless we are doing a full sync, 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 && |
| !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); |
| |
| for (j=0; j<conf->copies;j++) { |
| int d = r10_bio->devs[j].devnum; |
| if (!conf->mirrors[d].rdev || |
| !test_bit(In_sync, &conf->mirrors[d].rdev->flags)) |
| continue; |
| /* This is where we read from */ |
| 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; |
| bio->bi_sector = r10_bio->devs[j].addr + |
| conf->mirrors[d].rdev->data_offset; |
| bio->bi_bdev = conf->mirrors[d].rdev->bdev; |
| atomic_inc(&conf->mirrors[d].rdev->nr_pending); |
| atomic_inc(&r10_bio->remaining); |
| /* and we write to 'i' */ |
| |
| for (k=0; k<conf->copies; k++) |
| if (r10_bio->devs[k].devnum == i) |
| break; |
| BUG_ON(k == conf->copies); |
| 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 = r10_bio->devs[k].addr + |
| conf->mirrors[i].rdev->data_offset; |
| bio->bi_bdev = conf->mirrors[i].rdev->bdev; |
| |
| r10_bio->devs[0].devnum = d; |
| r10_bio->devs[1].devnum = i; |
| |
| break; |
| } |
| if (j == conf->copies) { |
| /* Cannot recover, so abort the recovery */ |
| put_buf(r10_bio); |
| if (rb2) |
| atomic_dec(&rb2->remaining); |
| r10_bio = rb2; |
| if (!test_and_set_bit(MD_RECOVERY_INTR, |
| &mddev->recovery)) |
| printk(KERN_INFO "md/raid10:%s: insufficient " |
| "working devices for recovery.\n", |
| mdname(mddev)); |
| break; |
| } |
| } |
| if (biolist == NULL) { |
| while (r10_bio) { |
| r10bio_t *rb2 = r10_bio; |
| r10_bio = (r10bio_t*) 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; |
| 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; |
| 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 = r10_bio->devs[i].addr + |
| conf->mirrors[d].rdev->data_offset; |
| bio->bi_bdev = conf->mirrors[d].rdev->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); |
| } |
| 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, 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(mddev_t *mddev, sector_t sectors, int raid_disks) |
| { |
| sector_t size; |
| conf_t *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 conf_t *setup_conf(mddev_t *mddev) |
| { |
| conf_t *conf = NULL; |
| int nc, fc, fo; |
| sector_t stride, size; |
| 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(conf_t), 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; |
| |
| size = mddev->dev_sectors >> conf->chunk_shift; |
| sector_div(size, fc); |
| size = size * conf->raid_disks; |
| sector_div(size, nc); |
| /* 'size' is now the number of chunks in the array */ |
| /* calculate "used chunks per device" in 'stride' */ |
| stride = size * conf->copies; |
| |
| /* We need to round up when dividing by raid_disks to |
| * get the stride size. |
| */ |
| stride += conf->raid_disks - 1; |
| sector_div(stride, conf->raid_disks); |
| |
| conf->dev_sectors = stride << conf->chunk_shift; |
| |
| if (fo) |
| stride = 1; |
| else |
| sector_div(stride, fc); |
| conf->stride = stride << conf->chunk_shift; |
| |
| |
| 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(mddev_t *mddev) |
| { |
| conf_t *conf; |
| int i, disk_idx, chunk_size; |
| mirror_info_t *disk; |
| mdk_rdev_t *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)); |
| |
| list_for_each_entry(rdev, &mddev->disks, same_set) { |
| disk_idx = rdev->raid_disk; |
| if (disk_idx >= conf->raid_disks |
| || disk_idx < 0) |
| continue; |
| disk = conf->mirrors + disk_idx; |
| |
| disk->rdev = rdev; |
| disk_stack_limits(mddev->gendisk, rdev->bdev, |
| rdev->data_offset << 9); |
| /* as we don't honour merge_bvec_fn, we must never risk |
| * violating it, so limit max_segments to 1 lying |
| * within a single page. |
| */ |
| if (rdev->bdev->bd_disk->queue->merge_bvec_fn) { |
| blk_queue_max_segments(mddev->queue, 1); |
| blk_queue_segment_boundary(mddev->queue, |
| PAGE_CACHE_SIZE - 1); |
| } |
| |
| disk->head_position = 0; |
| } |
| /* need to check that every block has at least one working mirror */ |
| if (!enough(conf)) { |
| 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 || |
| !test_bit(In_sync, &disk->rdev->flags)) { |
| disk->head_position = 0; |
| mddev->degraded++; |
| if (disk->rdev) |
| conf->fullsync = 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; |
| } |
| |
| if (conf->near_copies < conf->raid_disks) |
| 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(mddev_t *mddev) |
| { |
| conf_t *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(mddev_t *mddev, int state) |
| { |
| conf_t *conf = mddev->private; |
| |
| switch(state) { |
| case 1: |
| raise_barrier(conf, 0); |
| break; |
| case 0: |
| lower_barrier(conf); |
| break; |
| } |
| } |
| |
| static void *raid10_takeover_raid0(mddev_t *mddev) |
| { |
| mdk_rdev_t *rdev; |
| conf_t *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)) { |
| list_for_each_entry(rdev, &mddev->disks, same_set) |
| if (rdev->raid_disk >= 0) |
| rdev->new_raid_disk = rdev->raid_disk * 2; |
| conf->barrier = 1; |
| } |
| |
| return conf; |
| } |
| |
| static void *raid10_takeover(mddev_t *mddev) |
| { |
| struct raid0_private_data *raid0_priv; |
| |
| /* raid10 can take over: |
| * raid0 - providing it has only two drives |
| */ |
| if (mddev->level == 0) { |
| /* for raid0 takeover only one zone is supported */ |
| raid0_priv = mddev->private; |
| if (raid0_priv->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 mdk_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, |
| .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"); |