| /* |
| * raid1.c : Multiple Devices driver for Linux |
| * |
| * Copyright (C) 1999, 2000, 2001 Ingo Molnar, Red Hat |
| * |
| * Copyright (C) 1996, 1997, 1998 Ingo Molnar, Miguel de Icaza, Gadi Oxman |
| * |
| * RAID-1 management functions. |
| * |
| * Better read-balancing code written by Mika Kuoppala <miku@iki.fi>, 2000 |
| * |
| * Fixes to reconstruction by Jakob Østergaard" <jakob@ostenfeld.dk> |
| * Various fixes by Neil Brown <neilb@cse.unsw.edu.au> |
| * |
| * Changes by Peter T. Breuer <ptb@it.uc3m.es> 31/1/2003 to support |
| * bitmapped intelligence in resync: |
| * |
| * - bitmap marked during normal i/o |
| * - bitmap used to skip nondirty blocks during sync |
| * |
| * Additions to bitmap code, (C) 2003-2004 Paul Clements, SteelEye Technology: |
| * - persistent bitmap code |
| * |
| * 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 "raid1.h" |
| #include "bitmap.h" |
| |
| #define DEBUG 0 |
| #if DEBUG |
| #define PRINTK(x...) printk(x) |
| #else |
| #define PRINTK(x...) |
| #endif |
| |
| /* |
| * Number of guaranteed r1bios in case of extreme VM load: |
| */ |
| #define NR_RAID1_BIOS 256 |
| |
| |
| static void unplug_slaves(mddev_t *mddev); |
| |
| static void allow_barrier(conf_t *conf); |
| static void lower_barrier(conf_t *conf); |
| |
| static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data) |
| { |
| struct pool_info *pi = data; |
| r1bio_t *r1_bio; |
| int size = offsetof(r1bio_t, bios[pi->raid_disks]); |
| |
| /* allocate a r1bio with room for raid_disks entries in the bios array */ |
| r1_bio = kzalloc(size, gfp_flags); |
| if (!r1_bio && pi->mddev) |
| unplug_slaves(pi->mddev); |
| |
| return r1_bio; |
| } |
| |
| static void r1bio_pool_free(void *r1_bio, void *data) |
| { |
| kfree(r1_bio); |
| } |
| |
| #define RESYNC_BLOCK_SIZE (64*1024) |
| //#define RESYNC_BLOCK_SIZE PAGE_SIZE |
| #define RESYNC_SECTORS (RESYNC_BLOCK_SIZE >> 9) |
| #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE) |
| #define RESYNC_WINDOW (2048*1024) |
| |
| static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data) |
| { |
| struct pool_info *pi = data; |
| struct page *page; |
| r1bio_t *r1_bio; |
| struct bio *bio; |
| int i, j; |
| |
| r1_bio = r1bio_pool_alloc(gfp_flags, pi); |
| if (!r1_bio) { |
| unplug_slaves(pi->mddev); |
| return NULL; |
| } |
| |
| /* |
| * Allocate bios : 1 for reading, n-1 for writing |
| */ |
| for (j = pi->raid_disks ; j-- ; ) { |
| bio = bio_alloc(gfp_flags, RESYNC_PAGES); |
| if (!bio) |
| goto out_free_bio; |
| r1_bio->bios[j] = bio; |
| } |
| /* |
| * Allocate RESYNC_PAGES data pages and attach them to |
| * the first bio. |
| * If this is a user-requested check/repair, allocate |
| * RESYNC_PAGES for each bio. |
| */ |
| if (test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) |
| j = pi->raid_disks; |
| else |
| j = 1; |
| while(j--) { |
| bio = r1_bio->bios[j]; |
| 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; |
| bio->bi_vcnt = i+1; |
| } |
| } |
| /* If not user-requests, copy the page pointers to all bios */ |
| if (!test_bit(MD_RECOVERY_REQUESTED, &pi->mddev->recovery)) { |
| for (i=0; i<RESYNC_PAGES ; i++) |
| for (j=1; j<pi->raid_disks; j++) |
| r1_bio->bios[j]->bi_io_vec[i].bv_page = |
| r1_bio->bios[0]->bi_io_vec[i].bv_page; |
| } |
| |
| r1_bio->master_bio = NULL; |
| |
| return r1_bio; |
| |
| out_free_pages: |
| for (j=0 ; j < pi->raid_disks; j++) |
| for (i=0; i < r1_bio->bios[j]->bi_vcnt ; i++) |
| put_page(r1_bio->bios[j]->bi_io_vec[i].bv_page); |
| j = -1; |
| out_free_bio: |
| while ( ++j < pi->raid_disks ) |
| bio_put(r1_bio->bios[j]); |
| r1bio_pool_free(r1_bio, data); |
| return NULL; |
| } |
| |
| static void r1buf_pool_free(void *__r1_bio, void *data) |
| { |
| struct pool_info *pi = data; |
| int i,j; |
| r1bio_t *r1bio = __r1_bio; |
| |
| for (i = 0; i < RESYNC_PAGES; i++) |
| for (j = pi->raid_disks; j-- ;) { |
| if (j == 0 || |
| r1bio->bios[j]->bi_io_vec[i].bv_page != |
| r1bio->bios[0]->bi_io_vec[i].bv_page) |
| safe_put_page(r1bio->bios[j]->bi_io_vec[i].bv_page); |
| } |
| for (i=0 ; i < pi->raid_disks; i++) |
| bio_put(r1bio->bios[i]); |
| |
| r1bio_pool_free(r1bio, data); |
| } |
| |
| static void put_all_bios(conf_t *conf, r1bio_t *r1_bio) |
| { |
| int i; |
| |
| for (i = 0; i < conf->raid_disks; i++) { |
| struct bio **bio = r1_bio->bios + i; |
| if (*bio && *bio != IO_BLOCKED) |
| bio_put(*bio); |
| *bio = NULL; |
| } |
| } |
| |
| static void free_r1bio(r1bio_t *r1_bio) |
| { |
| conf_t *conf = r1_bio->mddev->private; |
| |
| /* |
| * Wake up any possible resync thread that waits for the device |
| * to go idle. |
| */ |
| allow_barrier(conf); |
| |
| put_all_bios(conf, r1_bio); |
| mempool_free(r1_bio, conf->r1bio_pool); |
| } |
| |
| static void put_buf(r1bio_t *r1_bio) |
| { |
| conf_t *conf = r1_bio->mddev->private; |
| int i; |
| |
| for (i=0; i<conf->raid_disks; i++) { |
| struct bio *bio = r1_bio->bios[i]; |
| if (bio->bi_end_io) |
| rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev); |
| } |
| |
| mempool_free(r1_bio, conf->r1buf_pool); |
| |
| lower_barrier(conf); |
| } |
| |
| static void reschedule_retry(r1bio_t *r1_bio) |
| { |
| unsigned long flags; |
| mddev_t *mddev = r1_bio->mddev; |
| conf_t *conf = mddev->private; |
| |
| spin_lock_irqsave(&conf->device_lock, flags); |
| list_add(&r1_bio->retry_list, &conf->retry_list); |
| conf->nr_queued ++; |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| |
| wake_up(&conf->wait_barrier); |
| md_wakeup_thread(mddev->thread); |
| } |
| |
| /* |
| * raid_end_bio_io() is called when we have finished servicing a mirrored |
| * operation and are ready to return a success/failure code to the buffer |
| * cache layer. |
| */ |
| static void raid_end_bio_io(r1bio_t *r1_bio) |
| { |
| struct bio *bio = r1_bio->master_bio; |
| |
| /* if nobody has done the final endio yet, do it now */ |
| if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { |
| PRINTK(KERN_DEBUG "raid1: sync end %s on sectors %llu-%llu\n", |
| (bio_data_dir(bio) == WRITE) ? "write" : "read", |
| (unsigned long long) bio->bi_sector, |
| (unsigned long long) bio->bi_sector + |
| (bio->bi_size >> 9) - 1); |
| |
| bio_endio(bio, |
| test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); |
| } |
| free_r1bio(r1_bio); |
| } |
| |
| /* |
| * Update disk head position estimator based on IRQ completion info. |
| */ |
| static inline void update_head_pos(int disk, r1bio_t *r1_bio) |
| { |
| conf_t *conf = r1_bio->mddev->private; |
| |
| conf->mirrors[disk].head_position = |
| r1_bio->sector + (r1_bio->sectors); |
| } |
| |
| static void raid1_end_read_request(struct bio *bio, int error) |
| { |
| int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| r1bio_t *r1_bio = bio->bi_private; |
| int mirror; |
| conf_t *conf = r1_bio->mddev->private; |
| |
| mirror = r1_bio->read_disk; |
| /* |
| * this branch is our 'one mirror IO has finished' event handler: |
| */ |
| update_head_pos(mirror, r1_bio); |
| |
| if (uptodate) |
| set_bit(R1BIO_Uptodate, &r1_bio->state); |
| else { |
| /* If all other devices have failed, we want to return |
| * the error upwards rather than fail the last device. |
| * Here we redefine "uptodate" to mean "Don't want to retry" |
| */ |
| unsigned long flags; |
| spin_lock_irqsave(&conf->device_lock, flags); |
| if (r1_bio->mddev->degraded == conf->raid_disks || |
| (r1_bio->mddev->degraded == conf->raid_disks-1 && |
| !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))) |
| uptodate = 1; |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| } |
| |
| if (uptodate) |
| raid_end_bio_io(r1_bio); |
| else { |
| /* |
| * oops, read error: |
| */ |
| char b[BDEVNAME_SIZE]; |
| if (printk_ratelimit()) |
| printk(KERN_ERR "md/raid1:%s: %s: rescheduling sector %llu\n", |
| mdname(conf->mddev), |
| bdevname(conf->mirrors[mirror].rdev->bdev,b), (unsigned long long)r1_bio->sector); |
| reschedule_retry(r1_bio); |
| } |
| |
| rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); |
| } |
| |
| static void r1_bio_write_done(r1bio_t *r1_bio, int vcnt, struct bio_vec *bv, |
| int behind) |
| { |
| if (atomic_dec_and_test(&r1_bio->remaining)) |
| { |
| /* it really is the end of this request */ |
| if (test_bit(R1BIO_BehindIO, &r1_bio->state)) { |
| /* free extra copy of the data pages */ |
| int i = vcnt; |
| while (i--) |
| safe_put_page(bv[i].bv_page); |
| } |
| /* clear the bitmap if all writes complete successfully */ |
| bitmap_endwrite(r1_bio->mddev->bitmap, r1_bio->sector, |
| r1_bio->sectors, |
| !test_bit(R1BIO_Degraded, &r1_bio->state), |
| behind); |
| md_write_end(r1_bio->mddev); |
| raid_end_bio_io(r1_bio); |
| } |
| } |
| |
| static void raid1_end_write_request(struct bio *bio, int error) |
| { |
| int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| r1bio_t *r1_bio = bio->bi_private; |
| int mirror, behind = test_bit(R1BIO_BehindIO, &r1_bio->state); |
| conf_t *conf = r1_bio->mddev->private; |
| struct bio *to_put = NULL; |
| |
| |
| for (mirror = 0; mirror < conf->raid_disks; mirror++) |
| if (r1_bio->bios[mirror] == bio) |
| break; |
| |
| /* |
| * 'one mirror IO has finished' event handler: |
| */ |
| r1_bio->bios[mirror] = NULL; |
| to_put = bio; |
| if (!uptodate) { |
| md_error(r1_bio->mddev, conf->mirrors[mirror].rdev); |
| /* an I/O failed, we can't clear the bitmap */ |
| set_bit(R1BIO_Degraded, &r1_bio->state); |
| } else |
| /* |
| * Set R1BIO_Uptodate in our master bio, so that we |
| * will return a good error code for to the higher |
| * levels even if IO on some other mirrored buffer |
| * fails. |
| * |
| * The 'master' represents the composite IO operation |
| * to user-side. So if something waits for IO, then it |
| * will wait for the 'master' bio. |
| */ |
| set_bit(R1BIO_Uptodate, &r1_bio->state); |
| |
| update_head_pos(mirror, r1_bio); |
| |
| if (behind) { |
| if (test_bit(WriteMostly, &conf->mirrors[mirror].rdev->flags)) |
| atomic_dec(&r1_bio->behind_remaining); |
| |
| /* |
| * In behind mode, we ACK the master bio once the I/O |
| * has safely reached all non-writemostly |
| * disks. Setting the Returned bit ensures that this |
| * gets done only once -- we don't ever want to return |
| * -EIO here, instead we'll wait |
| */ |
| if (atomic_read(&r1_bio->behind_remaining) >= (atomic_read(&r1_bio->remaining)-1) && |
| test_bit(R1BIO_Uptodate, &r1_bio->state)) { |
| /* Maybe we can return now */ |
| if (!test_and_set_bit(R1BIO_Returned, &r1_bio->state)) { |
| struct bio *mbio = r1_bio->master_bio; |
| PRINTK(KERN_DEBUG "raid1: behind end write sectors %llu-%llu\n", |
| (unsigned long long) mbio->bi_sector, |
| (unsigned long long) mbio->bi_sector + |
| (mbio->bi_size >> 9) - 1); |
| bio_endio(mbio, 0); |
| } |
| } |
| } |
| rdev_dec_pending(conf->mirrors[mirror].rdev, conf->mddev); |
| |
| /* |
| * Let's see if all mirrored write operations have finished |
| * already. |
| */ |
| r1_bio_write_done(r1_bio, bio->bi_vcnt, bio->bi_io_vec, behind); |
| |
| if (to_put) |
| bio_put(to_put); |
| } |
| |
| |
| /* |
| * This routine returns the disk from which the requested read should |
| * be done. There is a per-array 'next expected sequential IO' sector |
| * number - if this matches on the next IO then we use the last disk. |
| * There is also a per-disk 'last know head position' sector that is |
| * maintained from IRQ contexts, both the normal and the resync IO |
| * completion handlers update this position correctly. If there is no |
| * perfect sequential match then we pick the disk whose head is closest. |
| * |
| * If there are 2 mirrors in the same 2 devices, performance degrades |
| * because position is mirror, not device based. |
| * |
| * The rdev for the device selected will have nr_pending incremented. |
| */ |
| static int read_balance(conf_t *conf, r1bio_t *r1_bio) |
| { |
| const sector_t this_sector = r1_bio->sector; |
| int new_disk = conf->last_used, disk = new_disk; |
| int wonly_disk = -1; |
| const int sectors = r1_bio->sectors; |
| sector_t new_distance, current_distance; |
| mdk_rdev_t *rdev; |
| |
| rcu_read_lock(); |
| /* |
| * Check if we can balance. We can balance on the whole |
| * device if no resync is going on, or below the resync window. |
| * We take the first readable disk when above the resync window. |
| */ |
| retry: |
| if (conf->mddev->recovery_cp < MaxSector && |
| (this_sector + sectors >= conf->next_resync)) { |
| /* Choose the first operational device, for consistancy */ |
| new_disk = 0; |
| |
| for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev); |
| r1_bio->bios[new_disk] == IO_BLOCKED || |
| !rdev || !test_bit(In_sync, &rdev->flags) |
| || test_bit(WriteMostly, &rdev->flags); |
| rdev = rcu_dereference(conf->mirrors[++new_disk].rdev)) { |
| |
| if (rdev && test_bit(In_sync, &rdev->flags) && |
| r1_bio->bios[new_disk] != IO_BLOCKED) |
| wonly_disk = new_disk; |
| |
| if (new_disk == conf->raid_disks - 1) { |
| new_disk = wonly_disk; |
| break; |
| } |
| } |
| goto rb_out; |
| } |
| |
| |
| /* make sure the disk is operational */ |
| for (rdev = rcu_dereference(conf->mirrors[new_disk].rdev); |
| r1_bio->bios[new_disk] == IO_BLOCKED || |
| !rdev || !test_bit(In_sync, &rdev->flags) || |
| test_bit(WriteMostly, &rdev->flags); |
| rdev = rcu_dereference(conf->mirrors[new_disk].rdev)) { |
| |
| if (rdev && test_bit(In_sync, &rdev->flags) && |
| r1_bio->bios[new_disk] != IO_BLOCKED) |
| wonly_disk = new_disk; |
| |
| if (new_disk <= 0) |
| new_disk = conf->raid_disks; |
| new_disk--; |
| if (new_disk == disk) { |
| new_disk = wonly_disk; |
| break; |
| } |
| } |
| |
| if (new_disk < 0) |
| goto rb_out; |
| |
| disk = new_disk; |
| /* now disk == new_disk == starting point for search */ |
| |
| /* |
| * Don't change to another disk for sequential reads: |
| */ |
| if (conf->next_seq_sect == this_sector) |
| goto rb_out; |
| if (this_sector == conf->mirrors[new_disk].head_position) |
| goto rb_out; |
| |
| current_distance = abs(this_sector - conf->mirrors[disk].head_position); |
| |
| /* Find the disk whose head is closest */ |
| |
| do { |
| if (disk <= 0) |
| disk = conf->raid_disks; |
| disk--; |
| |
| rdev = rcu_dereference(conf->mirrors[disk].rdev); |
| |
| if (!rdev || r1_bio->bios[disk] == IO_BLOCKED || |
| !test_bit(In_sync, &rdev->flags) || |
| test_bit(WriteMostly, &rdev->flags)) |
| continue; |
| |
| if (!atomic_read(&rdev->nr_pending)) { |
| new_disk = disk; |
| break; |
| } |
| new_distance = abs(this_sector - conf->mirrors[disk].head_position); |
| if (new_distance < current_distance) { |
| current_distance = new_distance; |
| new_disk = disk; |
| } |
| } while (disk != conf->last_used); |
| |
| rb_out: |
| |
| |
| if (new_disk >= 0) { |
| rdev = rcu_dereference(conf->mirrors[new_disk].rdev); |
| if (!rdev) |
| goto retry; |
| atomic_inc(&rdev->nr_pending); |
| if (!test_bit(In_sync, &rdev->flags)) { |
| /* cannot risk returning a device that failed |
| * before we inc'ed nr_pending |
| */ |
| rdev_dec_pending(rdev, conf->mddev); |
| goto retry; |
| } |
| conf->next_seq_sect = this_sector + sectors; |
| conf->last_used = new_disk; |
| } |
| rcu_read_unlock(); |
| |
| return new_disk; |
| } |
| |
| static void unplug_slaves(mddev_t *mddev) |
| { |
| conf_t *conf = mddev->private; |
| int i; |
| |
| rcu_read_lock(); |
| for (i=0; i<mddev->raid_disks; i++) { |
| mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
| if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) { |
| struct request_queue *r_queue = bdev_get_queue(rdev->bdev); |
| |
| atomic_inc(&rdev->nr_pending); |
| rcu_read_unlock(); |
| |
| blk_unplug(r_queue); |
| |
| rdev_dec_pending(rdev, mddev); |
| rcu_read_lock(); |
| } |
| } |
| rcu_read_unlock(); |
| } |
| |
| static void raid1_unplug(struct request_queue *q) |
| { |
| mddev_t *mddev = q->queuedata; |
| |
| unplug_slaves(mddev); |
| md_wakeup_thread(mddev->thread); |
| } |
| |
| static int raid1_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 < mddev->raid_disks; 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); |
| |
| /* Note the '|| 1' - when read_balance prefers |
| * non-congested targets, it can be removed |
| */ |
| if ((bits & (1<<BDI_async_congested)) || 1) |
| ret |= bdi_congested(&q->backing_dev_info, bits); |
| else |
| ret &= bdi_congested(&q->backing_dev_info, bits); |
| } |
| } |
| rcu_read_unlock(); |
| return ret; |
| } |
| |
| |
| static int flush_pending_writes(conf_t *conf) |
| { |
| /* Any writes that have been queued but are awaiting |
| * bitmap updates get flushed here. |
| * We return 1 if any requests were actually submitted. |
| */ |
| int rv = 0; |
| |
| spin_lock_irq(&conf->device_lock); |
| |
| if (conf->pending_bio_list.head) { |
| struct bio *bio; |
| bio = bio_list_get(&conf->pending_bio_list); |
| blk_remove_plug(conf->mddev->queue); |
| 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; |
| } |
| rv = 1; |
| } else |
| spin_unlock_irq(&conf->device_lock); |
| return rv; |
| } |
| |
| /* 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. |
| */ |
| #define RESYNC_DEPTH 32 |
| |
| static void raise_barrier(conf_t *conf) |
| { |
| spin_lock_irq(&conf->resync_lock); |
| |
| /* Wait until no block IO is waiting */ |
| wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting, |
| conf->resync_lock, |
| raid1_unplug(conf->mddev->queue)); |
| |
| /* block any new IO from starting */ |
| conf->barrier++; |
| |
| /* No wait for all pending IO to complete */ |
| wait_event_lock_irq(conf->wait_barrier, |
| !conf->nr_pending && conf->barrier < RESYNC_DEPTH, |
| conf->resync_lock, |
| raid1_unplug(conf->mddev->queue)); |
| |
| spin_unlock_irq(&conf->resync_lock); |
| } |
| |
| static void lower_barrier(conf_t *conf) |
| { |
| unsigned long flags; |
| BUG_ON(conf->barrier <= 0); |
| 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, |
| raid1_unplug(conf->mddev->queue)); |
| 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 quite. |
| * 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); |
| raid1_unplug(conf->mddev->queue); })); |
| 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); |
| } |
| |
| |
| /* duplicate the data pages for behind I/O |
| * We return a list of bio_vec rather than just page pointers |
| * as it makes freeing easier |
| */ |
| static struct bio_vec *alloc_behind_pages(struct bio *bio) |
| { |
| int i; |
| struct bio_vec *bvec; |
| struct bio_vec *pages = kzalloc(bio->bi_vcnt * sizeof(struct bio_vec), |
| GFP_NOIO); |
| if (unlikely(!pages)) |
| goto do_sync_io; |
| |
| bio_for_each_segment(bvec, bio, i) { |
| pages[i].bv_page = alloc_page(GFP_NOIO); |
| if (unlikely(!pages[i].bv_page)) |
| goto do_sync_io; |
| memcpy(kmap(pages[i].bv_page) + bvec->bv_offset, |
| kmap(bvec->bv_page) + bvec->bv_offset, bvec->bv_len); |
| kunmap(pages[i].bv_page); |
| kunmap(bvec->bv_page); |
| } |
| |
| return pages; |
| |
| do_sync_io: |
| if (pages) |
| for (i = 0; i < bio->bi_vcnt && pages[i].bv_page; i++) |
| put_page(pages[i].bv_page); |
| kfree(pages); |
| PRINTK("%dB behind alloc failed, doing sync I/O\n", bio->bi_size); |
| return NULL; |
| } |
| |
| static int make_request(mddev_t *mddev, struct bio * bio) |
| { |
| conf_t *conf = mddev->private; |
| mirror_info_t *mirror; |
| r1bio_t *r1_bio; |
| struct bio *read_bio; |
| int i, targets = 0, disks; |
| struct bitmap *bitmap; |
| unsigned long flags; |
| struct bio_vec *behind_pages = NULL; |
| const int rw = bio_data_dir(bio); |
| const unsigned long do_sync = (bio->bi_rw & REQ_SYNC); |
| const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA)); |
| mdk_rdev_t *blocked_rdev; |
| |
| /* |
| * 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. |
| */ |
| |
| md_write_start(mddev, bio); /* wait on superblock update early */ |
| |
| if (bio_data_dir(bio) == WRITE && |
| bio->bi_sector + bio->bi_size/512 > mddev->suspend_lo && |
| bio->bi_sector < mddev->suspend_hi) { |
| /* As the suspend_* range is controlled by |
| * userspace, we want an interruptible |
| * wait. |
| */ |
| DEFINE_WAIT(w); |
| for (;;) { |
| flush_signals(current); |
| prepare_to_wait(&conf->wait_barrier, |
| &w, TASK_INTERRUPTIBLE); |
| if (bio->bi_sector + bio->bi_size/512 <= mddev->suspend_lo || |
| bio->bi_sector >= mddev->suspend_hi) |
| break; |
| schedule(); |
| } |
| finish_wait(&conf->wait_barrier, &w); |
| } |
| |
| wait_barrier(conf); |
| |
| bitmap = mddev->bitmap; |
| |
| /* |
| * make_request() can abort the operation when READA is being |
| * used and no empty request is available. |
| * |
| */ |
| r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); |
| |
| r1_bio->master_bio = bio; |
| r1_bio->sectors = bio->bi_size >> 9; |
| r1_bio->state = 0; |
| r1_bio->mddev = mddev; |
| r1_bio->sector = bio->bi_sector; |
| |
| if (rw == READ) { |
| /* |
| * read balancing logic: |
| */ |
| int rdisk = read_balance(conf, r1_bio); |
| |
| if (rdisk < 0) { |
| /* couldn't find anywhere to read from */ |
| raid_end_bio_io(r1_bio); |
| return 0; |
| } |
| mirror = conf->mirrors + rdisk; |
| |
| if (test_bit(WriteMostly, &mirror->rdev->flags) && |
| bitmap) { |
| /* Reading from a write-mostly device must |
| * take care not to over-take any writes |
| * that are 'behind' |
| */ |
| wait_event(bitmap->behind_wait, |
| atomic_read(&bitmap->behind_writes) == 0); |
| } |
| r1_bio->read_disk = rdisk; |
| |
| read_bio = bio_clone(bio, GFP_NOIO); |
| |
| r1_bio->bios[rdisk] = read_bio; |
| |
| read_bio->bi_sector = r1_bio->sector + mirror->rdev->data_offset; |
| read_bio->bi_bdev = mirror->rdev->bdev; |
| read_bio->bi_end_io = raid1_end_read_request; |
| read_bio->bi_rw = READ | do_sync; |
| read_bio->bi_private = r1_bio; |
| |
| generic_make_request(read_bio); |
| return 0; |
| } |
| |
| /* |
| * WRITE: |
| */ |
| /* first select target devices under spinlock and |
| * inc refcount on their rdev. Record them by setting |
| * bios[x] to bio |
| */ |
| disks = conf->raid_disks; |
| retry_write: |
| blocked_rdev = NULL; |
| rcu_read_lock(); |
| for (i = 0; i < disks; i++) { |
| mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].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); |
| if (test_bit(Faulty, &rdev->flags)) { |
| rdev_dec_pending(rdev, mddev); |
| r1_bio->bios[i] = NULL; |
| } else { |
| r1_bio->bios[i] = bio; |
| targets++; |
| } |
| } else |
| r1_bio->bios[i] = NULL; |
| } |
| rcu_read_unlock(); |
| |
| if (unlikely(blocked_rdev)) { |
| /* Wait for this device to become unblocked */ |
| int j; |
| |
| for (j = 0; j < i; j++) |
| if (r1_bio->bios[j]) |
| rdev_dec_pending(conf->mirrors[j].rdev, mddev); |
| |
| allow_barrier(conf); |
| md_wait_for_blocked_rdev(blocked_rdev, mddev); |
| wait_barrier(conf); |
| goto retry_write; |
| } |
| |
| BUG_ON(targets == 0); /* we never fail the last device */ |
| |
| if (targets < conf->raid_disks) { |
| /* array is degraded, we will not clear the bitmap |
| * on I/O completion (see raid1_end_write_request) */ |
| set_bit(R1BIO_Degraded, &r1_bio->state); |
| } |
| |
| /* do behind I/O ? |
| * Not if there are too many, or cannot allocate memory, |
| * or a reader on WriteMostly is waiting for behind writes |
| * to flush */ |
| if (bitmap && |
| (atomic_read(&bitmap->behind_writes) |
| < mddev->bitmap_info.max_write_behind) && |
| !waitqueue_active(&bitmap->behind_wait) && |
| (behind_pages = alloc_behind_pages(bio)) != NULL) |
| set_bit(R1BIO_BehindIO, &r1_bio->state); |
| |
| atomic_set(&r1_bio->remaining, 1); |
| atomic_set(&r1_bio->behind_remaining, 0); |
| |
| bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors, |
| test_bit(R1BIO_BehindIO, &r1_bio->state)); |
| for (i = 0; i < disks; i++) { |
| struct bio *mbio; |
| if (!r1_bio->bios[i]) |
| continue; |
| |
| mbio = bio_clone(bio, GFP_NOIO); |
| r1_bio->bios[i] = mbio; |
| |
| mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset; |
| mbio->bi_bdev = conf->mirrors[i].rdev->bdev; |
| mbio->bi_end_io = raid1_end_write_request; |
| mbio->bi_rw = WRITE | do_flush_fua | do_sync; |
| mbio->bi_private = r1_bio; |
| |
| if (behind_pages) { |
| struct bio_vec *bvec; |
| int j; |
| |
| /* Yes, I really want the '__' version so that |
| * we clear any unused pointer in the io_vec, rather |
| * than leave them unchanged. This is important |
| * because when we come to free the pages, we won't |
| * know the originial bi_idx, so we just free |
| * them all |
| */ |
| __bio_for_each_segment(bvec, mbio, j, 0) |
| bvec->bv_page = behind_pages[j].bv_page; |
| if (test_bit(WriteMostly, &conf->mirrors[i].rdev->flags)) |
| atomic_inc(&r1_bio->behind_remaining); |
| } |
| |
| atomic_inc(&r1_bio->remaining); |
| spin_lock_irqsave(&conf->device_lock, flags); |
| bio_list_add(&conf->pending_bio_list, mbio); |
| blk_plug_device(mddev->queue); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| } |
| r1_bio_write_done(r1_bio, bio->bi_vcnt, behind_pages, behind_pages != NULL); |
| kfree(behind_pages); /* the behind pages are attached to the bios now */ |
| |
| /* In case raid1d snuck in to freeze_array */ |
| wake_up(&conf->wait_barrier); |
| |
| if (do_sync) |
| md_wakeup_thread(mddev->thread); |
| |
| return 0; |
| } |
| |
| static void status(struct seq_file *seq, mddev_t *mddev) |
| { |
| conf_t *conf = mddev->private; |
| int i; |
| |
| seq_printf(seq, " [%d/%d] [", conf->raid_disks, |
| conf->raid_disks - mddev->degraded); |
| rcu_read_lock(); |
| for (i = 0; i < conf->raid_disks; i++) { |
| mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
| seq_printf(seq, "%s", |
| rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_"); |
| } |
| rcu_read_unlock(); |
| seq_printf(seq, "]"); |
| } |
| |
| |
| 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, act as though we were just a |
| * normal single drive. |
| * However don't try a recovery from this drive as |
| * it is very likely to fail. |
| */ |
| mddev->recovery_disabled = 1; |
| return; |
| } |
| if (test_and_clear_bit(In_sync, &rdev->flags)) { |
| unsigned long flags; |
| spin_lock_irqsave(&conf->device_lock, flags); |
| mddev->degraded++; |
| set_bit(Faulty, &rdev->flags); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| /* |
| * if recovery is running, make sure it aborts. |
| */ |
| set_bit(MD_RECOVERY_INTR, &mddev->recovery); |
| } else |
| set_bit(Faulty, &rdev->flags); |
| set_bit(MD_CHANGE_DEVS, &mddev->flags); |
| printk(KERN_ALERT "md/raid1:%s: Disk failure on %s, disabling device.\n" |
| KERN_ALERT "md/raid1:%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; |
| |
| printk(KERN_DEBUG "RAID1 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); |
| |
| rcu_read_lock(); |
| for (i = 0; i < conf->raid_disks; i++) { |
| char b[BDEVNAME_SIZE]; |
| mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev); |
| if (rdev) |
| printk(KERN_DEBUG " disk %d, wo:%d, o:%d, dev:%s\n", |
| i, !test_bit(In_sync, &rdev->flags), |
| !test_bit(Faulty, &rdev->flags), |
| bdevname(rdev->bdev,b)); |
| } |
| rcu_read_unlock(); |
| } |
| |
| static void close_sync(conf_t *conf) |
| { |
| wait_barrier(conf); |
| allow_barrier(conf); |
| |
| mempool_destroy(conf->r1buf_pool); |
| conf->r1buf_pool = NULL; |
| } |
| |
| static int raid1_spare_active(mddev_t *mddev) |
| { |
| int i; |
| conf_t *conf = mddev->private; |
| int count = 0; |
| unsigned long flags; |
| |
| /* |
| * Find all failed disks within the RAID1 configuration |
| * and mark them readable. |
| * Called under mddev lock, so rcu protection not needed. |
| */ |
| for (i = 0; i < conf->raid_disks; i++) { |
| mdk_rdev_t *rdev = conf->mirrors[i].rdev; |
| if (rdev |
| && !test_bit(Faulty, &rdev->flags) |
| && !test_and_set_bit(In_sync, &rdev->flags)) { |
| count++; |
| sysfs_notify_dirent(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 raid1_add_disk(mddev_t *mddev, mdk_rdev_t *rdev) |
| { |
| conf_t *conf = mddev->private; |
| int err = -EEXIST; |
| int mirror = 0; |
| mirror_info_t *p; |
| int first = 0; |
| int last = mddev->raid_disks - 1; |
| |
| if (rdev->raid_disk >= 0) |
| first = last = rdev->raid_disk; |
| |
| for (mirror = first; 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; |
| /* As all devices are equivalent, we don't need a full recovery |
| * if this was recently any drive of the array |
| */ |
| if (rdev->saved_raid_disk < 0) |
| conf->fullsync = 1; |
| rcu_assign_pointer(p->rdev, rdev); |
| break; |
| } |
| md_integrity_add_rdev(rdev, mddev); |
| print_conf(conf); |
| return err; |
| } |
| |
| static int raid1_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 non-faulty devices is recovery |
| * is not possible. |
| */ |
| if (!test_bit(Faulty, &rdev->flags) && |
| mddev->degraded < conf->raid_disks) { |
| 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; |
| } |
| md_integrity_register(mddev); |
| } |
| abort: |
| |
| print_conf(conf); |
| return err; |
| } |
| |
| |
| static void end_sync_read(struct bio *bio, int error) |
| { |
| r1bio_t *r1_bio = bio->bi_private; |
| int i; |
| |
| for (i=r1_bio->mddev->raid_disks; i--; ) |
| if (r1_bio->bios[i] == bio) |
| break; |
| BUG_ON(i < 0); |
| update_head_pos(i, r1_bio); |
| /* |
| * we have read a block, now it needs to be re-written, |
| * or re-read if the read failed. |
| * We don't do much here, just schedule handling by raid1d |
| */ |
| if (test_bit(BIO_UPTODATE, &bio->bi_flags)) |
| set_bit(R1BIO_Uptodate, &r1_bio->state); |
| |
| if (atomic_dec_and_test(&r1_bio->remaining)) |
| reschedule_retry(r1_bio); |
| } |
| |
| static void end_sync_write(struct bio *bio, int error) |
| { |
| int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| r1bio_t *r1_bio = bio->bi_private; |
| mddev_t *mddev = r1_bio->mddev; |
| conf_t *conf = mddev->private; |
| int i; |
| int mirror=0; |
| |
| for (i = 0; i < conf->raid_disks; i++) |
| if (r1_bio->bios[i] == bio) { |
| mirror = i; |
| break; |
| } |
| if (!uptodate) { |
| sector_t sync_blocks = 0; |
| sector_t s = r1_bio->sector; |
| long sectors_to_go = r1_bio->sectors; |
| /* make sure these bits doesn't get cleared. */ |
| do { |
| bitmap_end_sync(mddev->bitmap, s, |
| &sync_blocks, 1); |
| s += sync_blocks; |
| sectors_to_go -= sync_blocks; |
| } while (sectors_to_go > 0); |
| md_error(mddev, conf->mirrors[mirror].rdev); |
| } |
| |
| update_head_pos(mirror, r1_bio); |
| |
| if (atomic_dec_and_test(&r1_bio->remaining)) { |
| sector_t s = r1_bio->sectors; |
| put_buf(r1_bio); |
| md_done_sync(mddev, s, uptodate); |
| } |
| } |
| |
| static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) |
| { |
| conf_t *conf = mddev->private; |
| int i; |
| int disks = conf->raid_disks; |
| struct bio *bio, *wbio; |
| |
| bio = r1_bio->bios[r1_bio->read_disk]; |
| |
| |
| if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { |
| /* We have read all readable devices. If we haven't |
| * got the block, then there is no hope left. |
| * If we have, then we want to do a comparison |
| * and skip the write if everything is the same. |
| * If any blocks failed to read, then we need to |
| * attempt an over-write |
| */ |
| int primary; |
| if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { |
| for (i=0; i<mddev->raid_disks; i++) |
| if (r1_bio->bios[i]->bi_end_io == end_sync_read) |
| md_error(mddev, conf->mirrors[i].rdev); |
| |
| md_done_sync(mddev, r1_bio->sectors, 1); |
| put_buf(r1_bio); |
| return; |
| } |
| for (primary=0; primary<mddev->raid_disks; primary++) |
| if (r1_bio->bios[primary]->bi_end_io == end_sync_read && |
| test_bit(BIO_UPTODATE, &r1_bio->bios[primary]->bi_flags)) { |
| r1_bio->bios[primary]->bi_end_io = NULL; |
| rdev_dec_pending(conf->mirrors[primary].rdev, mddev); |
| break; |
| } |
| r1_bio->read_disk = primary; |
| for (i=0; i<mddev->raid_disks; i++) |
| if (r1_bio->bios[i]->bi_end_io == end_sync_read) { |
| int j; |
| int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9); |
| struct bio *pbio = r1_bio->bios[primary]; |
| struct bio *sbio = r1_bio->bios[i]; |
| |
| if (test_bit(BIO_UPTODATE, &sbio->bi_flags)) { |
| for (j = vcnt; j-- ; ) { |
| struct page *p, *s; |
| p = pbio->bi_io_vec[j].bv_page; |
| s = sbio->bi_io_vec[j].bv_page; |
| if (memcmp(page_address(p), |
| page_address(s), |
| PAGE_SIZE)) |
| break; |
| } |
| } else |
| j = 0; |
| if (j >= 0) |
| mddev->resync_mismatches += r1_bio->sectors; |
| if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery) |
| && test_bit(BIO_UPTODATE, &sbio->bi_flags))) { |
| sbio->bi_end_io = NULL; |
| rdev_dec_pending(conf->mirrors[i].rdev, mddev); |
| } else { |
| /* fixup the bio for reuse */ |
| int size; |
| sbio->bi_vcnt = vcnt; |
| sbio->bi_size = r1_bio->sectors << 9; |
| sbio->bi_idx = 0; |
| sbio->bi_phys_segments = 0; |
| sbio->bi_flags &= ~(BIO_POOL_MASK - 1); |
| sbio->bi_flags |= 1 << BIO_UPTODATE; |
| sbio->bi_next = NULL; |
| sbio->bi_sector = r1_bio->sector + |
| conf->mirrors[i].rdev->data_offset; |
| sbio->bi_bdev = conf->mirrors[i].rdev->bdev; |
| size = sbio->bi_size; |
| for (j = 0; j < vcnt ; j++) { |
| struct bio_vec *bi; |
| bi = &sbio->bi_io_vec[j]; |
| bi->bv_offset = 0; |
| if (size > PAGE_SIZE) |
| bi->bv_len = PAGE_SIZE; |
| else |
| bi->bv_len = size; |
| size -= PAGE_SIZE; |
| memcpy(page_address(bi->bv_page), |
| page_address(pbio->bi_io_vec[j].bv_page), |
| PAGE_SIZE); |
| } |
| |
| } |
| } |
| } |
| if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) { |
| /* ouch - failed to read all of that. |
| * Try some synchronous reads of other devices to get |
| * good data, much like with normal read errors. Only |
| * read into the pages we already have so we don't |
| * need to re-issue the read request. |
| * We don't need to freeze the array, because being in an |
| * active sync request, there is no normal IO, and |
| * no overlapping syncs. |
| */ |
| sector_t sect = r1_bio->sector; |
| int sectors = r1_bio->sectors; |
| int idx = 0; |
| |
| while(sectors) { |
| int s = sectors; |
| int d = r1_bio->read_disk; |
| int success = 0; |
| mdk_rdev_t *rdev; |
| |
| if (s > (PAGE_SIZE>>9)) |
| s = PAGE_SIZE >> 9; |
| do { |
| if (r1_bio->bios[d]->bi_end_io == end_sync_read) { |
| /* No rcu protection needed here devices |
| * can only be removed when no resync is |
| * active, and resync is currently active |
| */ |
| rdev = conf->mirrors[d].rdev; |
| if (sync_page_io(rdev->bdev, |
| sect + rdev->data_offset, |
| s<<9, |
| bio->bi_io_vec[idx].bv_page, |
| READ)) { |
| success = 1; |
| break; |
| } |
| } |
| d++; |
| if (d == conf->raid_disks) |
| d = 0; |
| } while (!success && d != r1_bio->read_disk); |
| |
| if (success) { |
| int start = d; |
| /* write it back and re-read */ |
| set_bit(R1BIO_Uptodate, &r1_bio->state); |
| while (d != r1_bio->read_disk) { |
| if (d == 0) |
| d = conf->raid_disks; |
| d--; |
| if (r1_bio->bios[d]->bi_end_io != end_sync_read) |
| continue; |
| rdev = conf->mirrors[d].rdev; |
| atomic_add(s, &rdev->corrected_errors); |
| if (sync_page_io(rdev->bdev, |
| sect + rdev->data_offset, |
| s<<9, |
| bio->bi_io_vec[idx].bv_page, |
| WRITE) == 0) |
| md_error(mddev, rdev); |
| } |
| d = start; |
| while (d != r1_bio->read_disk) { |
| if (d == 0) |
| d = conf->raid_disks; |
| d--; |
| if (r1_bio->bios[d]->bi_end_io != end_sync_read) |
| continue; |
| rdev = conf->mirrors[d].rdev; |
| if (sync_page_io(rdev->bdev, |
| sect + rdev->data_offset, |
| s<<9, |
| bio->bi_io_vec[idx].bv_page, |
| READ) == 0) |
| md_error(mddev, rdev); |
| } |
| } else { |
| char b[BDEVNAME_SIZE]; |
| /* Cannot read from anywhere, array is toast */ |
| md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev); |
| printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O read error" |
| " for block %llu\n", |
| mdname(mddev), |
| bdevname(bio->bi_bdev, b), |
| (unsigned long long)r1_bio->sector); |
| md_done_sync(mddev, r1_bio->sectors, 0); |
| put_buf(r1_bio); |
| return; |
| } |
| sectors -= s; |
| sect += s; |
| idx ++; |
| } |
| } |
| |
| /* |
| * schedule writes |
| */ |
| atomic_set(&r1_bio->remaining, 1); |
| for (i = 0; i < disks ; i++) { |
| wbio = r1_bio->bios[i]; |
| if (wbio->bi_end_io == NULL || |
| (wbio->bi_end_io == end_sync_read && |
| (i == r1_bio->read_disk || |
| !test_bit(MD_RECOVERY_SYNC, &mddev->recovery)))) |
| continue; |
| |
| wbio->bi_rw = WRITE; |
| wbio->bi_end_io = end_sync_write; |
| atomic_inc(&r1_bio->remaining); |
| md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9); |
| |
| generic_make_request(wbio); |
| } |
| |
| if (atomic_dec_and_test(&r1_bio->remaining)) { |
| /* if we're here, all write(s) have completed, so clean up */ |
| md_done_sync(mddev, r1_bio->sectors, 1); |
| put_buf(r1_bio); |
| } |
| } |
| |
| /* |
| * 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 syncronising. |
| */ |
| |
| static void fix_read_error(conf_t *conf, int read_disk, |
| sector_t sect, int sectors) |
| { |
| mddev_t *mddev = conf->mddev; |
| while(sectors) { |
| int s = sectors; |
| int d = read_disk; |
| int success = 0; |
| int start; |
| mdk_rdev_t *rdev; |
| |
| if (s > (PAGE_SIZE>>9)) |
| s = PAGE_SIZE >> 9; |
| |
| do { |
| /* Note: no rcu protection needed here |
| * as this is synchronous in the raid1d thread |
| * which is the thread that might remove |
| * a device. If raid1d ever becomes multi-threaded.... |
| */ |
| rdev = conf->mirrors[d].rdev; |
| if (rdev && |
| test_bit(In_sync, &rdev->flags) && |
| sync_page_io(rdev->bdev, |
| sect + rdev->data_offset, |
| s<<9, |
| conf->tmppage, READ)) |
| success = 1; |
| else { |
| d++; |
| if (d == conf->raid_disks) |
| d = 0; |
| } |
| } while (!success && d != read_disk); |
| |
| if (!success) { |
| /* Cannot read from anywhere -- bye bye array */ |
| md_error(mddev, conf->mirrors[read_disk].rdev); |
| break; |
| } |
| /* write it back and re-read */ |
| start = d; |
| while (d != read_disk) { |
| if (d==0) |
| d = conf->raid_disks; |
| d--; |
| rdev = conf->mirrors[d].rdev; |
| if (rdev && |
| test_bit(In_sync, &rdev->flags)) { |
| if (sync_page_io(rdev->bdev, |
| sect + rdev->data_offset, |
| s<<9, conf->tmppage, WRITE) |
| == 0) |
| /* Well, this device is dead */ |
| md_error(mddev, rdev); |
| } |
| } |
| d = start; |
| while (d != read_disk) { |
| char b[BDEVNAME_SIZE]; |
| if (d==0) |
| d = conf->raid_disks; |
| d--; |
| rdev = conf->mirrors[d].rdev; |
| if (rdev && |
| test_bit(In_sync, &rdev->flags)) { |
| if (sync_page_io(rdev->bdev, |
| sect + rdev->data_offset, |
| s<<9, conf->tmppage, READ) |
| == 0) |
| /* Well, this device is dead */ |
| md_error(mddev, rdev); |
| else { |
| atomic_add(s, &rdev->corrected_errors); |
| printk(KERN_INFO |
| "md/raid1:%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)); |
| } |
| } |
| } |
| sectors -= s; |
| sect += s; |
| } |
| } |
| |
| static void raid1d(mddev_t *mddev) |
| { |
| r1bio_t *r1_bio; |
| struct bio *bio; |
| unsigned long flags; |
| conf_t *conf = mddev->private; |
| struct list_head *head = &conf->retry_list; |
| int unplug=0; |
| mdk_rdev_t *rdev; |
| |
| md_check_recovery(mddev); |
| |
| for (;;) { |
| char b[BDEVNAME_SIZE]; |
| |
| unplug += flush_pending_writes(conf); |
| |
| spin_lock_irqsave(&conf->device_lock, flags); |
| if (list_empty(head)) { |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| break; |
| } |
| r1_bio = list_entry(head->prev, r1bio_t, retry_list); |
| list_del(head->prev); |
| conf->nr_queued--; |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| |
| mddev = r1_bio->mddev; |
| conf = mddev->private; |
| if (test_bit(R1BIO_IsSync, &r1_bio->state)) { |
| sync_request_write(mddev, r1_bio); |
| unplug = 1; |
| } else { |
| int disk; |
| |
| /* 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, r1_bio->read_disk, |
| r1_bio->sector, |
| r1_bio->sectors); |
| unfreeze_array(conf); |
| } else |
| md_error(mddev, |
| conf->mirrors[r1_bio->read_disk].rdev); |
| |
| bio = r1_bio->bios[r1_bio->read_disk]; |
| if ((disk=read_balance(conf, r1_bio)) == -1) { |
| printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O" |
| " read error for block %llu\n", |
| mdname(mddev), |
| bdevname(bio->bi_bdev,b), |
| (unsigned long long)r1_bio->sector); |
| raid_end_bio_io(r1_bio); |
| } else { |
| const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC; |
| r1_bio->bios[r1_bio->read_disk] = |
| mddev->ro ? IO_BLOCKED : NULL; |
| r1_bio->read_disk = disk; |
| bio_put(bio); |
| bio = bio_clone(r1_bio->master_bio, GFP_NOIO); |
| r1_bio->bios[r1_bio->read_disk] = bio; |
| rdev = conf->mirrors[disk].rdev; |
| if (printk_ratelimit()) |
| printk(KERN_ERR "md/raid1:%s: redirecting sector %llu to" |
| " other mirror: %s\n", |
| mdname(mddev), |
| (unsigned long long)r1_bio->sector, |
| bdevname(rdev->bdev,b)); |
| bio->bi_sector = r1_bio->sector + rdev->data_offset; |
| bio->bi_bdev = rdev->bdev; |
| bio->bi_end_io = raid1_end_read_request; |
| bio->bi_rw = READ | do_sync; |
| bio->bi_private = r1_bio; |
| unplug = 1; |
| generic_make_request(bio); |
| } |
| } |
| cond_resched(); |
| } |
| if (unplug) |
| unplug_slaves(mddev); |
| } |
| |
| |
| static int init_resync(conf_t *conf) |
| { |
| int buffs; |
| |
| buffs = RESYNC_WINDOW / RESYNC_BLOCK_SIZE; |
| BUG_ON(conf->r1buf_pool); |
| conf->r1buf_pool = mempool_create(buffs, r1buf_pool_alloc, r1buf_pool_free, |
| conf->poolinfo); |
| if (!conf->r1buf_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. |
| */ |
| |
| static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster) |
| { |
| conf_t *conf = mddev->private; |
| r1bio_t *r1_bio; |
| struct bio *bio; |
| sector_t max_sector, nr_sectors; |
| int disk = -1; |
| int i; |
| int wonly = -1; |
| int write_targets = 0, read_targets = 0; |
| sector_t sync_blocks; |
| int still_degraded = 0; |
| |
| if (!conf->r1buf_pool) |
| if (init_resync(conf)) |
| return 0; |
| |
| max_sector = mddev->dev_sectors; |
| if (sector_nr >= max_sector) { |
| /* If we aborted, we need to abort the |
| * sync on the 'current' bitmap chunk (there will |
| * only be one in raid1 resync. |
| * We can find the current addess in mddev->curr_resync |
| */ |
| if (mddev->curr_resync < max_sector) /* aborted */ |
| bitmap_end_sync(mddev->bitmap, mddev->curr_resync, |
| &sync_blocks, 1); |
| else /* completed sync */ |
| conf->fullsync = 0; |
| |
| bitmap_close_sync(mddev->bitmap); |
| close_sync(conf); |
| return 0; |
| } |
| |
| if (mddev->bitmap == NULL && |
| mddev->recovery_cp == MaxSector && |
| !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery) && |
| conf->fullsync == 0) { |
| *skipped = 1; |
| return max_sector - sector_nr; |
| } |
| /* before building a request, check if we can skip these blocks.. |
| * This call the bitmap_start_sync doesn't actually record anything |
| */ |
| if (!bitmap_start_sync(mddev->bitmap, sector_nr, &sync_blocks, 1) && |
| !conf->fullsync && !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { |
| /* We can skip this block, and probably several more */ |
| *skipped = 1; |
| return sync_blocks; |
| } |
| /* |
| * If there is non-resync activity waiting for a turn, |
| * and resync is going fast enough, |
| * then let it though before starting on this new sync request. |
| */ |
| if (!go_faster && conf->nr_waiting) |
| msleep_interruptible(1000); |
| |
| bitmap_cond_end_sync(mddev->bitmap, sector_nr); |
| raise_barrier(conf); |
| |
| conf->next_resync = sector_nr; |
| |
| r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO); |
| rcu_read_lock(); |
| /* |
| * If we get a correctably read error during resync or recovery, |
| * we might want to read from a different device. So we |
| * flag all drives that could conceivably be read from for READ, |
| * and any others (which will be non-In_sync devices) for WRITE. |
| * If a read fails, we try reading from something else for which READ |
| * is OK. |
| */ |
| |
| r1_bio->mddev = mddev; |
| r1_bio->sector = sector_nr; |
| r1_bio->state = 0; |
| set_bit(R1BIO_IsSync, &r1_bio->state); |
| |
| for (i=0; i < conf->raid_disks; i++) { |
| mdk_rdev_t *rdev; |
| bio = r1_bio->bios[i]; |
| |
| /* take from bio_init */ |
| bio->bi_next = NULL; |
| bio->bi_flags &= ~(BIO_POOL_MASK-1); |
| bio->bi_flags |= 1 << BIO_UPTODATE; |
| bio->bi_comp_cpu = -1; |
| bio->bi_rw = READ; |
| bio->bi_vcnt = 0; |
| bio->bi_idx = 0; |
| bio->bi_phys_segments = 0; |
| bio->bi_size = 0; |
| bio->bi_end_io = NULL; |
| bio->bi_private = NULL; |
| |
| rdev = rcu_dereference(conf->mirrors[i].rdev); |
| if (rdev == NULL || |
| test_bit(Faulty, &rdev->flags)) { |
| still_degraded = 1; |
| continue; |
| } else if (!test_bit(In_sync, &rdev->flags)) { |
| bio->bi_rw = WRITE; |
| bio->bi_end_io = end_sync_write; |
| write_targets ++; |
| } else { |
| /* may need to read from here */ |
| bio->bi_rw = READ; |
| bio->bi_end_io = end_sync_read; |
| if (test_bit(WriteMostly, &rdev->flags)) { |
| if (wonly < 0) |
| wonly = i; |
| } else { |
| if (disk < 0) |
| disk = i; |
| } |
| read_targets++; |
| } |
| atomic_inc(&rdev->nr_pending); |
| bio->bi_sector = sector_nr + rdev->data_offset; |
| bio->bi_bdev = rdev->bdev; |
| bio->bi_private = r1_bio; |
| } |
| rcu_read_unlock(); |
| if (disk < 0) |
| disk = wonly; |
| r1_bio->read_disk = disk; |
| |
| if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0) |
| /* extra read targets are also write targets */ |
| write_targets += read_targets-1; |
| |
| if (write_targets == 0 || read_targets == 0) { |
| /* There is nowhere to write, so all non-sync |
| * drives must be failed - so we are finished |
| */ |
| sector_t rv = max_sector - sector_nr; |
| *skipped = 1; |
| put_buf(r1_bio); |
| return rv; |
| } |
| |
| if (max_sector > mddev->resync_max) |
| max_sector = mddev->resync_max; /* Don't do IO beyond here */ |
| nr_sectors = 0; |
| sync_blocks = 0; |
| do { |
| struct page *page; |
| int len = PAGE_SIZE; |
| if (sector_nr + (len>>9) > max_sector) |
| len = (max_sector - sector_nr) << 9; |
| if (len == 0) |
| break; |
| if (sync_blocks == 0) { |
| if (!bitmap_start_sync(mddev->bitmap, sector_nr, |
| &sync_blocks, still_degraded) && |
| !conf->fullsync && |
| !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) |
| break; |
| BUG_ON(sync_blocks < (PAGE_SIZE>>9)); |
| if ((len >> 9) > sync_blocks) |
| len = sync_blocks<<9; |
| } |
| |
| for (i=0 ; i < conf->raid_disks; i++) { |
| bio = r1_bio->bios[i]; |
| if (bio->bi_end_io) { |
| page = bio->bi_io_vec[bio->bi_vcnt].bv_page; |
| if (bio_add_page(bio, page, len, 0) == 0) { |
| /* stop here */ |
| bio->bi_io_vec[bio->bi_vcnt].bv_page = page; |
| while (i > 0) { |
| i--; |
| bio = r1_bio->bios[i]; |
| if (bio->bi_end_io==NULL) |
| continue; |
| /* remove last page from this bio */ |
| bio->bi_vcnt--; |
| bio->bi_size -= len; |
| bio->bi_flags &= ~(1<< BIO_SEG_VALID); |
| } |
| goto bio_full; |
| } |
| } |
| } |
| nr_sectors += len>>9; |
| sector_nr += len>>9; |
| sync_blocks -= (len>>9); |
| } while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES); |
| bio_full: |
| r1_bio->sectors = nr_sectors; |
| |
| /* For a user-requested sync, we read all readable devices and do a |
| * compare |
| */ |
| if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) { |
| atomic_set(&r1_bio->remaining, read_targets); |
| for (i=0; i<conf->raid_disks; i++) { |
| bio = r1_bio->bios[i]; |
| if (bio->bi_end_io == end_sync_read) { |
| md_sync_acct(bio->bi_bdev, nr_sectors); |
| generic_make_request(bio); |
| } |
| } |
| } else { |
| atomic_set(&r1_bio->remaining, 1); |
| bio = r1_bio->bios[r1_bio->read_disk]; |
| md_sync_acct(bio->bi_bdev, nr_sectors); |
| generic_make_request(bio); |
| |
| } |
| return nr_sectors; |
| } |
| |
| static sector_t raid1_size(mddev_t *mddev, sector_t sectors, int raid_disks) |
| { |
| if (sectors) |
| return sectors; |
| |
| return mddev->dev_sectors; |
| } |
| |
| static conf_t *setup_conf(mddev_t *mddev) |
| { |
| conf_t *conf; |
| int i; |
| mirror_info_t *disk; |
| mdk_rdev_t *rdev; |
| int err = -ENOMEM; |
| |
| conf = kzalloc(sizeof(conf_t), GFP_KERNEL); |
| if (!conf) |
| goto abort; |
| |
| conf->mirrors = kzalloc(sizeof(struct mirror_info)*mddev->raid_disks, |
| GFP_KERNEL); |
| if (!conf->mirrors) |
| goto abort; |
| |
| conf->tmppage = alloc_page(GFP_KERNEL); |
| if (!conf->tmppage) |
| goto abort; |
| |
| conf->poolinfo = kzalloc(sizeof(*conf->poolinfo), GFP_KERNEL); |
| if (!conf->poolinfo) |
| goto abort; |
| conf->poolinfo->raid_disks = mddev->raid_disks; |
| conf->r1bio_pool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, |
| r1bio_pool_free, |
| conf->poolinfo); |
| if (!conf->r1bio_pool) |
| goto abort; |
| |
| conf->poolinfo->mddev = mddev; |
| |
| spin_lock_init(&conf->device_lock); |
| list_for_each_entry(rdev, &mddev->disks, same_set) { |
| int disk_idx = rdev->raid_disk; |
| if (disk_idx >= mddev->raid_disks |
| || disk_idx < 0) |
| continue; |
| disk = conf->mirrors + disk_idx; |
| |
| disk->rdev = rdev; |
| |
| disk->head_position = 0; |
| } |
| conf->raid_disks = mddev->raid_disks; |
| conf->mddev = mddev; |
| INIT_LIST_HEAD(&conf->retry_list); |
| |
| spin_lock_init(&conf->resync_lock); |
| init_waitqueue_head(&conf->wait_barrier); |
| |
| bio_list_init(&conf->pending_bio_list); |
| bio_list_init(&conf->flushing_bio_list); |
| |
| conf->last_used = -1; |
| 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; |
| if (disk->rdev) |
| conf->fullsync = 1; |
| } else if (conf->last_used < 0) |
| /* |
| * The first working device is used as a |
| * starting point to read balancing. |
| */ |
| conf->last_used = i; |
| } |
| |
| err = -EIO; |
| if (conf->last_used < 0) { |
| printk(KERN_ERR "md/raid1:%s: no operational mirrors\n", |
| mdname(mddev)); |
| goto abort; |
| } |
| err = -ENOMEM; |
| conf->thread = md_register_thread(raid1d, mddev, NULL); |
| if (!conf->thread) { |
| printk(KERN_ERR |
| "md/raid1:%s: couldn't allocate thread\n", |
| mdname(mddev)); |
| goto abort; |
| } |
| |
| return conf; |
| |
| abort: |
| if (conf) { |
| if (conf->r1bio_pool) |
| mempool_destroy(conf->r1bio_pool); |
| kfree(conf->mirrors); |
| safe_put_page(conf->tmppage); |
| kfree(conf->poolinfo); |
| kfree(conf); |
| } |
| return ERR_PTR(err); |
| } |
| |
| static int run(mddev_t *mddev) |
| { |
| conf_t *conf; |
| int i; |
| mdk_rdev_t *rdev; |
| |
| if (mddev->level != 1) { |
| printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n", |
| mdname(mddev), mddev->level); |
| return -EIO; |
| } |
| if (mddev->reshape_position != MaxSector) { |
| printk(KERN_ERR "md/raid1:%s: reshape_position set but not supported\n", |
| mdname(mddev)); |
| return -EIO; |
| } |
| /* |
| * copy the already verified devices into our private RAID1 |
| * bookkeeping area. [whatever we allocate in run(), |
| * should be freed in stop()] |
| */ |
| if (mddev->private == NULL) |
| conf = setup_conf(mddev); |
| else |
| conf = mddev->private; |
| |
| if (IS_ERR(conf)) |
| return PTR_ERR(conf); |
| |
| mddev->queue->queue_lock = &conf->device_lock; |
| list_for_each_entry(rdev, &mddev->disks, same_set) { |
| 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, 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); |
| } |
| } |
| |
| mddev->degraded = 0; |
| for (i=0; i < conf->raid_disks; i++) |
| if (conf->mirrors[i].rdev == NULL || |
| !test_bit(In_sync, &conf->mirrors[i].rdev->flags) || |
| test_bit(Faulty, &conf->mirrors[i].rdev->flags)) |
| mddev->degraded++; |
| |
| if (conf->raid_disks - mddev->degraded == 1) |
| mddev->recovery_cp = MaxSector; |
| |
| if (mddev->recovery_cp != MaxSector) |
| printk(KERN_NOTICE "md/raid1:%s: not clean" |
| " -- starting background reconstruction\n", |
| mdname(mddev)); |
| printk(KERN_INFO |
| "md/raid1:%s: active with %d out of %d mirrors\n", |
| mdname(mddev), mddev->raid_disks - mddev->degraded, |
| mddev->raid_disks); |
| |
| /* |
| * Ok, everything is just fine now |
| */ |
| mddev->thread = conf->thread; |
| conf->thread = NULL; |
| mddev->private = conf; |
| |
| md_set_array_sectors(mddev, raid1_size(mddev, 0, 0)); |
| |
| mddev->queue->unplug_fn = raid1_unplug; |
| mddev->queue->backing_dev_info.congested_fn = raid1_congested; |
| mddev->queue->backing_dev_info.congested_data = mddev; |
| md_integrity_register(mddev); |
| return 0; |
| } |
| |
| static int stop(mddev_t *mddev) |
| { |
| conf_t *conf = mddev->private; |
| struct bitmap *bitmap = mddev->bitmap; |
| |
| /* wait for behind writes to complete */ |
| if (bitmap && atomic_read(&bitmap->behind_writes) > 0) { |
| printk(KERN_INFO "md/raid1:%s: behind writes in progress - waiting to stop.\n", |
| mdname(mddev)); |
| /* need to kick something here to make sure I/O goes? */ |
| wait_event(bitmap->behind_wait, |
| atomic_read(&bitmap->behind_writes) == 0); |
| } |
| |
| raise_barrier(conf); |
| lower_barrier(conf); |
| |
| md_unregister_thread(mddev->thread); |
| mddev->thread = NULL; |
| blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/ |
| if (conf->r1bio_pool) |
| mempool_destroy(conf->r1bio_pool); |
| kfree(conf->mirrors); |
| kfree(conf->poolinfo); |
| kfree(conf); |
| mddev->private = NULL; |
| return 0; |
| } |
| |
| static int raid1_resize(mddev_t *mddev, sector_t sectors) |
| { |
| /* no resync is happening, and there is enough space |
| * on all devices, so we can resize. |
| * We need to make sure resync covers any new space. |
| * If the array is shrinking we should possibly wait until |
| * any io in the removed space completes, but it hardly seems |
| * worth it. |
| */ |
| md_set_array_sectors(mddev, raid1_size(mddev, sectors, 0)); |
| if (mddev->array_sectors > raid1_size(mddev, sectors, 0)) |
| return -EINVAL; |
| set_capacity(mddev->gendisk, mddev->array_sectors); |
| revalidate_disk(mddev->gendisk); |
| if (sectors > mddev->dev_sectors && |
| mddev->recovery_cp == MaxSector) { |
| mddev->recovery_cp = mddev->dev_sectors; |
| set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); |
| } |
| mddev->dev_sectors = sectors; |
| mddev->resync_max_sectors = sectors; |
| return 0; |
| } |
| |
| static int raid1_reshape(mddev_t *mddev) |
| { |
| /* We need to: |
| * 1/ resize the r1bio_pool |
| * 2/ resize conf->mirrors |
| * |
| * We allocate a new r1bio_pool if we can. |
| * Then raise a device barrier and wait until all IO stops. |
| * Then resize conf->mirrors and swap in the new r1bio pool. |
| * |
| * At the same time, we "pack" the devices so that all the missing |
| * devices have the higher raid_disk numbers. |
| */ |
| mempool_t *newpool, *oldpool; |
| struct pool_info *newpoolinfo; |
| mirror_info_t *newmirrors; |
| conf_t *conf = mddev->private; |
| int cnt, raid_disks; |
| unsigned long flags; |
| int d, d2, err; |
| |
| /* Cannot change chunk_size, layout, or level */ |
| if (mddev->chunk_sectors != mddev->new_chunk_sectors || |
| mddev->layout != mddev->new_layout || |
| mddev->level != mddev->new_level) { |
| mddev->new_chunk_sectors = mddev->chunk_sectors; |
| mddev->new_layout = mddev->layout; |
| mddev->new_level = mddev->level; |
| return -EINVAL; |
| } |
| |
| err = md_allow_write(mddev); |
| if (err) |
| return err; |
| |
| raid_disks = mddev->raid_disks + mddev->delta_disks; |
| |
| if (raid_disks < conf->raid_disks) { |
| cnt=0; |
| for (d= 0; d < conf->raid_disks; d++) |
| if (conf->mirrors[d].rdev) |
| cnt++; |
| if (cnt > raid_disks) |
| return -EBUSY; |
| } |
| |
| newpoolinfo = kmalloc(sizeof(*newpoolinfo), GFP_KERNEL); |
| if (!newpoolinfo) |
| return -ENOMEM; |
| newpoolinfo->mddev = mddev; |
| newpoolinfo->raid_disks = raid_disks; |
| |
| newpool = mempool_create(NR_RAID1_BIOS, r1bio_pool_alloc, |
| r1bio_pool_free, newpoolinfo); |
| if (!newpool) { |
| kfree(newpoolinfo); |
| return -ENOMEM; |
| } |
| newmirrors = kzalloc(sizeof(struct mirror_info) * raid_disks, GFP_KERNEL); |
| if (!newmirrors) { |
| kfree(newpoolinfo); |
| mempool_destroy(newpool); |
| return -ENOMEM; |
| } |
| |
| raise_barrier(conf); |
| |
| /* ok, everything is stopped */ |
| oldpool = conf->r1bio_pool; |
| conf->r1bio_pool = newpool; |
| |
| for (d = d2 = 0; d < conf->raid_disks; d++) { |
| mdk_rdev_t *rdev = conf->mirrors[d].rdev; |
| if (rdev && rdev->raid_disk != d2) { |
| char nm[20]; |
| sprintf(nm, "rd%d", rdev->raid_disk); |
| sysfs_remove_link(&mddev->kobj, nm); |
| rdev->raid_disk = d2; |
| sprintf(nm, "rd%d", rdev->raid_disk); |
| sysfs_remove_link(&mddev->kobj, nm); |
| if (sysfs_create_link(&mddev->kobj, |
| &rdev->kobj, nm)) |
| printk(KERN_WARNING |
| "md/raid1:%s: cannot register " |
| "%s\n", |
| mdname(mddev), nm); |
| } |
| if (rdev) |
| newmirrors[d2++].rdev = rdev; |
| } |
| kfree(conf->mirrors); |
| conf->mirrors = newmirrors; |
| kfree(conf->poolinfo); |
| conf->poolinfo = newpoolinfo; |
| |
| spin_lock_irqsave(&conf->device_lock, flags); |
| mddev->degraded += (raid_disks - conf->raid_disks); |
| spin_unlock_irqrestore(&conf->device_lock, flags); |
| conf->raid_disks = mddev->raid_disks = raid_disks; |
| mddev->delta_disks = 0; |
| |
| conf->last_used = 0; /* just make sure it is in-range */ |
| lower_barrier(conf); |
| |
| set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); |
| md_wakeup_thread(mddev->thread); |
| |
| mempool_destroy(oldpool); |
| return 0; |
| } |
| |
| static void raid1_quiesce(mddev_t *mddev, int state) |
| { |
| conf_t *conf = mddev->private; |
| |
| switch(state) { |
| case 2: /* wake for suspend */ |
| wake_up(&conf->wait_barrier); |
| break; |
| case 1: |
| raise_barrier(conf); |
| break; |
| case 0: |
| lower_barrier(conf); |
| break; |
| } |
| } |
| |
| static void *raid1_takeover(mddev_t *mddev) |
| { |
| /* raid1 can take over: |
| * raid5 with 2 devices, any layout or chunk size |
| */ |
| if (mddev->level == 5 && mddev->raid_disks == 2) { |
| conf_t *conf; |
| mddev->new_level = 1; |
| mddev->new_layout = 0; |
| mddev->new_chunk_sectors = 0; |
| conf = setup_conf(mddev); |
| if (!IS_ERR(conf)) |
| conf->barrier = 1; |
| return conf; |
| } |
| return ERR_PTR(-EINVAL); |
| } |
| |
| static struct mdk_personality raid1_personality = |
| { |
| .name = "raid1", |
| .level = 1, |
| .owner = THIS_MODULE, |
| .make_request = make_request, |
| .run = run, |
| .stop = stop, |
| .status = status, |
| .error_handler = error, |
| .hot_add_disk = raid1_add_disk, |
| .hot_remove_disk= raid1_remove_disk, |
| .spare_active = raid1_spare_active, |
| .sync_request = sync_request, |
| .resize = raid1_resize, |
| .size = raid1_size, |
| .check_reshape = raid1_reshape, |
| .quiesce = raid1_quiesce, |
| .takeover = raid1_takeover, |
| }; |
| |
| static int __init raid_init(void) |
| { |
| return register_md_personality(&raid1_personality); |
| } |
| |
| static void raid_exit(void) |
| { |
| unregister_md_personality(&raid1_personality); |
| } |
| |
| module_init(raid_init); |
| module_exit(raid_exit); |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("RAID1 (mirroring) personality for MD"); |
| MODULE_ALIAS("md-personality-3"); /* RAID1 */ |
| MODULE_ALIAS("md-raid1"); |
| MODULE_ALIAS("md-level-1"); |