diff options
Diffstat (limited to 'drivers/md/dm-raid1.c')
-rw-r--r-- | drivers/md/dm-raid1.c | 664 |
1 files changed, 576 insertions, 88 deletions
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index 31123d4a6b9..2928ef22810 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -6,6 +6,7 @@ #include "dm.h" #include "dm-bio-list.h" +#include "dm-bio-record.h" #include "dm-io.h" #include "dm-log.h" #include "kcopyd.h" @@ -20,6 +21,7 @@ #include <linux/vmalloc.h> #include <linux/workqueue.h> #include <linux/log2.h> +#include <linux/hardirq.h> #define DM_MSG_PREFIX "raid1" #define DM_IO_PAGES 64 @@ -113,9 +115,16 @@ struct region { /*----------------------------------------------------------------- * Mirror set structures. *---------------------------------------------------------------*/ +enum dm_raid1_error { + DM_RAID1_WRITE_ERROR, + DM_RAID1_SYNC_ERROR, + DM_RAID1_READ_ERROR +}; + struct mirror { struct mirror_set *ms; atomic_t error_count; + unsigned long error_type; struct dm_dev *dev; sector_t offset; }; @@ -127,21 +136,25 @@ struct mirror_set { struct kcopyd_client *kcopyd_client; uint64_t features; - spinlock_t lock; /* protects the next two lists */ + spinlock_t lock; /* protects the lists */ struct bio_list reads; struct bio_list writes; + struct bio_list failures; struct dm_io_client *io_client; + mempool_t *read_record_pool; /* recovery */ region_t nr_regions; int in_sync; int log_failure; + atomic_t suspend; - struct mirror *default_mirror; /* Default mirror */ + atomic_t default_mirror; /* Default mirror */ struct workqueue_struct *kmirrord_wq; struct work_struct kmirrord_work; + struct work_struct trigger_event; unsigned int nr_mirrors; struct mirror mirror[0]; @@ -362,6 +375,16 @@ static void complete_resync_work(struct region *reg, int success) struct region_hash *rh = reg->rh; rh->log->type->set_region_sync(rh->log, reg->key, success); + + /* + * Dispatch the bios before we call 'wake_up_all'. + * This is important because if we are suspending, + * we want to know that recovery is complete and + * the work queue is flushed. If we wake_up_all + * before we dispatch_bios (queue bios and call wake()), + * then we risk suspending before the work queue + * has been properly flushed. + */ dispatch_bios(rh->ms, ®->delayed_bios); if (atomic_dec_and_test(&rh->recovery_in_flight)) wake_up_all(&_kmirrord_recovery_stopped); @@ -626,24 +649,101 @@ static void rh_start_recovery(struct region_hash *rh) wake(rh->ms); } +#define MIN_READ_RECORDS 20 +struct dm_raid1_read_record { + struct mirror *m; + struct dm_bio_details details; +}; + /* * Every mirror should look like this one. */ #define DEFAULT_MIRROR 0 /* - * This is yucky. We squirrel the mirror_set struct away inside - * bi_next for write buffers. This is safe since the bh + * This is yucky. We squirrel the mirror struct away inside + * bi_next for read/write buffers. This is safe since the bh * doesn't get submitted to the lower levels of block layer. */ -static struct mirror_set *bio_get_ms(struct bio *bio) +static struct mirror *bio_get_m(struct bio *bio) +{ + return (struct mirror *) bio->bi_next; +} + +static void bio_set_m(struct bio *bio, struct mirror *m) +{ + bio->bi_next = (struct bio *) m; +} + +static struct mirror *get_default_mirror(struct mirror_set *ms) { - return (struct mirror_set *) bio->bi_next; + return &ms->mirror[atomic_read(&ms->default_mirror)]; } -static void bio_set_ms(struct bio *bio, struct mirror_set *ms) +static void set_default_mirror(struct mirror *m) { - bio->bi_next = (struct bio *) ms; + struct mirror_set *ms = m->ms; + struct mirror *m0 = &(ms->mirror[0]); + + atomic_set(&ms->default_mirror, m - m0); +} + +/* fail_mirror + * @m: mirror device to fail + * @error_type: one of the enum's, DM_RAID1_*_ERROR + * + * If errors are being handled, record the type of + * error encountered for this device. If this type + * of error has already been recorded, we can return; + * otherwise, we must signal userspace by triggering + * an event. Additionally, if the device is the + * primary device, we must choose a new primary, but + * only if the mirror is in-sync. + * + * This function must not block. + */ +static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type) +{ + struct mirror_set *ms = m->ms; + struct mirror *new; + + if (!errors_handled(ms)) + return; + + /* + * error_count is used for nothing more than a + * simple way to tell if a device has encountered + * errors. + */ + atomic_inc(&m->error_count); + + if (test_and_set_bit(error_type, &m->error_type)) + return; + + if (m != get_default_mirror(ms)) + goto out; + + if (!ms->in_sync) { + /* + * Better to issue requests to same failing device + * than to risk returning corrupt data. + */ + DMERR("Primary mirror (%s) failed while out-of-sync: " + "Reads may fail.", m->dev->name); + goto out; + } + + for (new = ms->mirror; new < ms->mirror + ms->nr_mirrors; new++) + if (!atomic_read(&new->error_count)) { + set_default_mirror(new); + break; + } + + if (unlikely(new == ms->mirror + ms->nr_mirrors)) + DMWARN("All sides of mirror have failed."); + +out: + schedule_work(&ms->trigger_event); } /*----------------------------------------------------------------- @@ -656,15 +756,32 @@ static void bio_set_ms(struct bio *bio, struct mirror_set *ms) static void recovery_complete(int read_err, unsigned int write_err, void *context) { - struct region *reg = (struct region *) context; + struct region *reg = (struct region *)context; + struct mirror_set *ms = reg->rh->ms; + int m, bit = 0; - if (read_err) + if (read_err) { /* Read error means the failure of default mirror. */ DMERR_LIMIT("Unable to read primary mirror during recovery"); + fail_mirror(get_default_mirror(ms), DM_RAID1_SYNC_ERROR); + } - if (write_err) + if (write_err) { DMERR_LIMIT("Write error during recovery (error = 0x%x)", write_err); + /* + * Bits correspond to devices (excluding default mirror). + * The default mirror cannot change during recovery. + */ + for (m = 0; m < ms->nr_mirrors; m++) { + if (&ms->mirror[m] == get_default_mirror(ms)) + continue; + if (test_bit(bit, &write_err)) + fail_mirror(ms->mirror + m, + DM_RAID1_SYNC_ERROR); + bit++; + } + } rh_recovery_end(reg, !(read_err || write_err)); } @@ -678,7 +795,7 @@ static int recover(struct mirror_set *ms, struct region *reg) unsigned long flags = 0; /* fill in the source */ - m = ms->default_mirror; + m = get_default_mirror(ms); from.bdev = m->dev->bdev; from.sector = m->offset + region_to_sector(reg->rh, reg->key); if (reg->key == (ms->nr_regions - 1)) { @@ -694,7 +811,7 @@ static int recover(struct mirror_set *ms, struct region *reg) /* fill in the destinations */ for (i = 0, dest = to; i < ms->nr_mirrors; i++) { - if (&ms->mirror[i] == ms->default_mirror) + if (&ms->mirror[i] == get_default_mirror(ms)) continue; m = ms->mirror + i; @@ -748,17 +865,105 @@ static void do_recovery(struct mirror_set *ms) *---------------------------------------------------------------*/ static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector) { - /* FIXME: add read balancing */ - return ms->default_mirror; + struct mirror *m = get_default_mirror(ms); + + do { + if (likely(!atomic_read(&m->error_count))) + return m; + + if (m-- == ms->mirror) + m += ms->nr_mirrors; + } while (m != get_default_mirror(ms)); + + return NULL; +} + +static int default_ok(struct mirror *m) +{ + struct mirror *default_mirror = get_default_mirror(m->ms); + + return !atomic_read(&default_mirror->error_count); +} + +static int mirror_available(struct mirror_set *ms, struct bio *bio) +{ + region_t region = bio_to_region(&ms->rh, bio); + + if (ms->rh.log->type->in_sync(ms->rh.log, region, 0)) + return choose_mirror(ms, bio->bi_sector) ? 1 : 0; + + return 0; } /* * remap a buffer to a particular mirror. */ -static void map_bio(struct mirror_set *ms, struct mirror *m, struct bio *bio) +static sector_t map_sector(struct mirror *m, struct bio *bio) +{ + return m->offset + (bio->bi_sector - m->ms->ti->begin); +} + +static void map_bio(struct mirror *m, struct bio *bio) { bio->bi_bdev = m->dev->bdev; - bio->bi_sector = m->offset + (bio->bi_sector - ms->ti->begin); + bio->bi_sector = map_sector(m, bio); +} + +static void map_region(struct io_region *io, struct mirror *m, + struct bio *bio) +{ + io->bdev = m->dev->bdev; + io->sector = map_sector(m, bio); + io->count = bio->bi_size >> 9; +} + +/*----------------------------------------------------------------- + * Reads + *---------------------------------------------------------------*/ +static void read_callback(unsigned long error, void *context) +{ + struct bio *bio = context; + struct mirror *m; + + m = bio_get_m(bio); + bio_set_m(bio, NULL); + + if (likely(!error)) { + bio_endio(bio, 0); + return; + } + + fail_mirror(m, DM_RAID1_READ_ERROR); + + if (likely(default_ok(m)) || mirror_available(m->ms, bio)) { + DMWARN_LIMIT("Read failure on mirror device %s. " + "Trying alternative device.", + m->dev->name); + queue_bio(m->ms, bio, bio_rw(bio)); + return; + } + + DMERR_LIMIT("Read failure on mirror device %s. Failing I/O.", + m->dev->name); + bio_endio(bio, -EIO); +} + +/* Asynchronous read. */ +static void read_async_bio(struct mirror *m, struct bio *bio) +{ + struct io_region io; + struct dm_io_request io_req = { + .bi_rw = READ, + .mem.type = DM_IO_BVEC, + .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx, + .notify.fn = read_callback, + .notify.context = bio, + .client = m->ms->io_client, + }; + + map_region(&io, m, bio); + bio_set_m(bio, m); + (void) dm_io(&io_req, 1, &io, NULL); } static void do_reads(struct mirror_set *ms, struct bio_list *reads) @@ -769,17 +974,20 @@ static void do_reads(struct mirror_set *ms, struct bio_list *reads) while ((bio = bio_list_pop(reads))) { region = bio_to_region(&ms->rh, bio); + m = get_default_mirror(ms); /* * We can only read balance if the region is in sync. */ - if (rh_in_sync(&ms->rh, region, 1)) + if (likely(rh_in_sync(&ms->rh, region, 1))) m = choose_mirror(ms, bio->bi_sector); - else - m = ms->default_mirror; + else if (m && atomic_read(&m->error_count)) + m = NULL; - map_bio(ms, m, bio); - generic_make_request(bio); + if (likely(m)) + read_async_bio(m, bio); + else + bio_endio(bio, -EIO); } } @@ -793,15 +1001,70 @@ static void do_reads(struct mirror_set *ms, struct bio_list *reads) * RECOVERING: delay the io until recovery completes * NOSYNC: increment pending, just write to the default mirror *---------------------------------------------------------------*/ + +/* __bio_mark_nosync + * @ms + * @bio + * @done + * @error + * + * The bio was written on some mirror(s) but failed on other mirror(s). + * We can successfully endio the bio but should avoid the region being + * marked clean by setting the state RH_NOSYNC. + * + * This function is _not_ safe in interrupt context! + */ +static void __bio_mark_nosync(struct mirror_set *ms, + struct bio *bio, unsigned done, int error) +{ + unsigned long flags; + struct region_hash *rh = &ms->rh; + struct dirty_log *log = ms->rh.log; + struct region *reg; + region_t region = bio_to_region(rh, bio); + int recovering = 0; + + /* We must inform the log that the sync count has changed. */ + log->type->set_region_sync(log, region, 0); + ms->in_sync = 0; + + read_lock(&rh->hash_lock); + reg = __rh_find(rh, region); + read_unlock(&rh->hash_lock); + + /* region hash entry should exist because write was in-flight */ + BUG_ON(!reg); + BUG_ON(!list_empty(®->list)); + + spin_lock_irqsave(&rh->region_lock, flags); + /* + * Possible cases: + * 1) RH_DIRTY + * 2) RH_NOSYNC: was dirty, other preceeding writes failed + * 3) RH_RECOVERING: flushing pending writes + * Either case, the region should have not been connected to list. + */ + recovering = (reg->state == RH_RECOVERING); + reg->state = RH_NOSYNC; + BUG_ON(!list_empty(®->list)); + spin_unlock_irqrestore(&rh->region_lock, flags); + + bio_endio(bio, error); + if (recovering) + complete_resync_work(reg, 0); +} + static void write_callback(unsigned long error, void *context) { - unsigned int i; - int uptodate = 1; + unsigned i, ret = 0; struct bio *bio = (struct bio *) context; struct mirror_set *ms; + int uptodate = 0; + int should_wake = 0; + unsigned long flags; - ms = bio_get_ms(bio); - bio_set_ms(bio, NULL); + ms = bio_get_m(bio)->ms; + bio_set_m(bio, NULL); /* * NOTE: We don't decrement the pending count here, @@ -809,26 +1072,42 @@ static void write_callback(unsigned long error, void *context) * This way we handle both writes to SYNC and NOSYNC * regions with the same code. */ + if (likely(!error)) + goto out; + + for (i = 0; i < ms->nr_mirrors; i++) + if (test_bit(i, &error)) + fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR); + else + uptodate = 1; - if (error) { + if (unlikely(!uptodate)) { + DMERR("All replicated volumes dead, failing I/O"); + /* None of the writes succeeded, fail the I/O. */ + ret = -EIO; + } else if (errors_handled(ms)) { /* - * only error the io if all mirrors failed. - * FIXME: bogus + * Need to raise event. Since raising + * events can block, we need to do it in + * the main thread. */ - uptodate = 0; - for (i = 0; i < ms->nr_mirrors; i++) - if (!test_bit(i, &error)) { - uptodate = 1; - break; - } + spin_lock_irqsave(&ms->lock, flags); + if (!ms->failures.head) + should_wake = 1; + bio_list_add(&ms->failures, bio); + spin_unlock_irqrestore(&ms->lock, flags); + if (should_wake) + wake(ms); + return; } - bio_endio(bio, 0); +out: + bio_endio(bio, ret); } static void do_write(struct mirror_set *ms, struct bio *bio) { unsigned int i; - struct io_region io[KCOPYD_MAX_REGIONS+1]; + struct io_region io[ms->nr_mirrors], *dest = io; struct mirror *m; struct dm_io_request io_req = { .bi_rw = WRITE, @@ -839,15 +1118,14 @@ static void do_write(struct mirror_set *ms, struct bio *bio) .client = ms->io_client, }; - for (i = 0; i < ms->nr_mirrors; i++) { - m = ms->mirror + i; - - io[i].bdev = m->dev->bdev; - io[i].sector = m->offset + (bio->bi_sector - ms->ti->begin); - io[i].count = bio->bi_size >> 9; - } + for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) + map_region(dest++, m, bio); - bio_set_ms(bio, ms); + /* + * Use default mirror because we only need it to retrieve the reference + * to the mirror set in write_callback(). + */ + bio_set_m(bio, get_default_mirror(ms)); (void) dm_io(&io_req, ms->nr_mirrors, io, NULL); } @@ -900,43 +1178,125 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes) /* * Dispatch io. */ - if (unlikely(ms->log_failure)) + if (unlikely(ms->log_failure)) { + spin_lock_irq(&ms->lock); + bio_list_merge(&ms->failures, &sync); + spin_unlock_irq(&ms->lock); + } else while ((bio = bio_list_pop(&sync))) - bio_endio(bio, -EIO); - else while ((bio = bio_list_pop(&sync))) - do_write(ms, bio); + do_write(ms, bio); while ((bio = bio_list_pop(&recover))) rh_delay(&ms->rh, bio); while ((bio = bio_list_pop(&nosync))) { - map_bio(ms, ms->default_mirror, bio); + map_bio(get_default_mirror(ms), bio); generic_make_request(bio); } } +static void do_failures(struct mirror_set *ms, struct bio_list *failures) +{ + struct bio *bio; + + if (!failures->head) + return; + + if (!ms->log_failure) { + while ((bio = bio_list_pop(failures))) + __bio_mark_nosync(ms, bio, bio->bi_size, 0); + return; + } + + /* + * If the log has failed, unattempted writes are being + * put on the failures list. We can't issue those writes + * until a log has been marked, so we must store them. + * + * If a 'noflush' suspend is in progress, we can requeue + * the I/O's to the core. This give userspace a chance + * to reconfigure the mirror, at which point the core + * will reissue the writes. If the 'noflush' flag is + * not set, we have no choice but to return errors. + * + * Some writes on the failures list may have been + * submitted before the log failure and represent a + * failure to write to one of the devices. It is ok + * for us to treat them the same and requeue them + * as well. + */ + if (dm_noflush_suspending(ms->ti)) { + while ((bio = bio_list_pop(failures))) + bio_endio(bio, DM_ENDIO_REQUEUE); + return; + } + + if (atomic_read(&ms->suspend)) { + while ((bio = bio_list_pop(failures))) + bio_endio(bio, -EIO); + return; + } + + spin_lock_irq(&ms->lock); + bio_list_merge(&ms->failures, failures); + spin_unlock_irq(&ms->lock); + + wake(ms); +} + +static void trigger_event(struct work_struct *work) +{ + struct mirror_set *ms = + container_of(work, struct mirror_set, trigger_event); + + dm_table_event(ms->ti->table); +} + /*----------------------------------------------------------------- * kmirrord *---------------------------------------------------------------*/ -static void do_mirror(struct work_struct *work) +static int _do_mirror(struct work_struct *work) { struct mirror_set *ms =container_of(work, struct mirror_set, kmirrord_work); - struct bio_list reads, writes; + struct bio_list reads, writes, failures; + unsigned long flags; - spin_lock(&ms->lock); + spin_lock_irqsave(&ms->lock, flags); reads = ms->reads; writes = ms->writes; + failures = ms->failures; bio_list_init(&ms->reads); bio_list_init(&ms->writes); - spin_unlock(&ms->lock); + bio_list_init(&ms->failures); + spin_unlock_irqrestore(&ms->lock, flags); rh_update_states(&ms->rh); do_recovery(ms); do_reads(ms, &reads); do_writes(ms, &writes); + do_failures(ms, &failures); + + return (ms->failures.head) ? 1 : 0; } +static void do_mirror(struct work_struct *work) +{ + /* + * If _do_mirror returns 1, we give it + * another shot. This helps for cases like + * 'suspend' where we call flush_workqueue + * and expect all work to be finished. If + * a failure happens during a suspend, we + * couldn't issue a 'wake' because it would + * not be honored. Therefore, we return '1' + * from _do_mirror, and retry here. + */ + while (_do_mirror(work)) + schedule(); +} + + /*----------------------------------------------------------------- * Target functions *---------------------------------------------------------------*/ @@ -965,11 +1325,23 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors, ms->nr_mirrors = nr_mirrors; ms->nr_regions = dm_sector_div_up(ti->len, region_size); ms->in_sync = 0; - ms->default_mirror = &ms->mirror[DEFAULT_MIRROR]; + ms->log_failure = 0; + atomic_set(&ms->suspend, 0); + atomic_set(&ms->default_mirror, DEFAULT_MIRROR); + + len = sizeof(struct dm_raid1_read_record); + ms->read_record_pool = mempool_create_kmalloc_pool(MIN_READ_RECORDS, + len); + if (!ms->read_record_pool) { + ti->error = "Error creating mirror read_record_pool"; + kfree(ms); + return NULL; + } ms->io_client = dm_io_client_create(DM_IO_PAGES); if (IS_ERR(ms->io_client)) { ti->error = "Error creating dm_io client"; + mempool_destroy(ms->read_record_pool); kfree(ms); return NULL; } @@ -977,6 +1349,7 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors, if (rh_init(&ms->rh, ms, dl, region_size, ms->nr_regions)) { ti->error = "Error creating dirty region hash"; dm_io_client_destroy(ms->io_client); + mempool_destroy(ms->read_record_pool); kfree(ms); return NULL; } @@ -992,6 +1365,7 @@ static void free_context(struct mirror_set *ms, struct dm_target *ti, dm_io_client_destroy(ms->io_client); rh_exit(&ms->rh); + mempool_destroy(ms->read_record_pool); kfree(ms); } @@ -1019,6 +1393,8 @@ static int get_mirror(struct mirror_set *ms, struct dm_target *ti, } ms->mirror[mirror].ms = ms; + atomic_set(&(ms->mirror[mirror].error_count), 0); + ms->mirror[mirror].error_type = 0; ms->mirror[mirror].offset = offset; return 0; @@ -1171,6 +1547,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv) goto err_free_context; } INIT_WORK(&ms->kmirrord_work, do_mirror); + INIT_WORK(&ms->trigger_event, trigger_event); r = parse_features(ms, argc, argv, &args_used); if (r) @@ -1220,14 +1597,15 @@ static void mirror_dtr(struct dm_target *ti) static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw) { + unsigned long flags; int should_wake = 0; struct bio_list *bl; bl = (rw == WRITE) ? &ms->writes : &ms->reads; - spin_lock(&ms->lock); + spin_lock_irqsave(&ms->lock, flags); should_wake = !(bl->head); bio_list_add(bl, bio); - spin_unlock(&ms->lock); + spin_unlock_irqrestore(&ms->lock, flags); if (should_wake) wake(ms); @@ -1242,10 +1620,11 @@ static int mirror_map(struct dm_target *ti, struct bio *bio, int r, rw = bio_rw(bio); struct mirror *m; struct mirror_set *ms = ti->private; - - map_context->ll = bio_to_region(&ms->rh, bio); + struct dm_raid1_read_record *read_record = NULL; if (rw == WRITE) { + /* Save region for mirror_end_io() handler */ + map_context->ll = bio_to_region(&ms->rh, bio); queue_bio(ms, bio, rw); return DM_MAPIO_SUBMITTED; } @@ -1255,28 +1634,34 @@ static int mirror_map(struct dm_target *ti, struct bio *bio, if (r < 0 && r != -EWOULDBLOCK) return r; - if (r == -EWOULDBLOCK) /* FIXME: ugly */ - r = DM_MAPIO_SUBMITTED; - /* - * We don't want to fast track a recovery just for a read - * ahead. So we just let it silently fail. - * FIXME: get rid of this. + * If region is not in-sync queue the bio. */ - if (!r && rw == READA) - return -EIO; + if (!r || (r == -EWOULDBLOCK)) { + if (rw == READA) + return -EWOULDBLOCK; - if (!r) { - /* Pass this io over to the daemon */ queue_bio(ms, bio, rw); return DM_MAPIO_SUBMITTED; } + /* + * The region is in-sync and we can perform reads directly. + * Store enough information so we can retry if it fails. + */ m = choose_mirror(ms, bio->bi_sector); - if (!m) + if (unlikely(!m)) return -EIO; - map_bio(ms, m, bio); + read_record = mempool_alloc(ms->read_record_pool, GFP_NOIO); + if (likely(read_record)) { + dm_bio_record(&read_record->details, bio); + map_context->ptr = read_record; + read_record->m = m; + } + + map_bio(m, bio); + return DM_MAPIO_REMAPPED; } @@ -1285,71 +1670,173 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, { int rw = bio_rw(bio); struct mirror_set *ms = (struct mirror_set *) ti->private; - region_t region = map_context->ll; + struct mirror *m = NULL; + struct dm_bio_details *bd = NULL; + struct dm_raid1_read_record *read_record = map_context->ptr; /* * We need to dec pending if this was a write. */ - if (rw == WRITE) - rh_dec(&ms->rh, region); + if (rw == WRITE) { + rh_dec(&ms->rh, map_context->ll); + return error; + } - return 0; + if (error == -EOPNOTSUPP) + goto out; + + if ((error == -EWOULDBLOCK) && bio_rw_ahead(bio)) + goto out; + + if (unlikely(error)) { + if (!read_record) { + /* + * There wasn't enough memory to record necessary + * information for a retry or there was no other + * mirror in-sync. + */ + DMERR_LIMIT("Mirror read failed from %s.", + m->dev->name); + return -EIO; + } + DMERR("Mirror read failed from %s. Trying alternative device.", + m->dev->name); + + m = read_record->m; + fail_mirror(m, DM_RAID1_READ_ERROR); + + /* + * A failed read is requeued for another attempt using an intact + * mirror. + */ + if (default_ok(m) || mirror_available(ms, bio)) { + bd = &read_record->details; + + dm_bio_restore(bd, bio); + mempool_free(read_record, ms->read_record_pool); + map_context->ptr = NULL; + queue_bio(ms, bio, rw); + return 1; + } + DMERR("All replicated volumes dead, failing I/O"); + } + +out: + if (read_record) { + mempool_free(read_record, ms->read_record_pool); + map_context->ptr = NULL; + } + + return error; } -static void mirror_postsuspend(struct dm_target *ti) +static void mirror_presuspend(struct dm_target *ti) { struct mirror_set *ms = (struct mirror_set *) ti->private; struct dirty_log *log = ms->rh.log; + atomic_set(&ms->suspend, 1); + + /* + * We must finish up all the work that we've + * generated (i.e. recovery work). + */ rh_stop_recovery(&ms->rh); - /* Wait for all I/O we generated to complete */ wait_event(_kmirrord_recovery_stopped, !atomic_read(&ms->rh.recovery_in_flight)); + if (log->type->presuspend && log->type->presuspend(log)) + /* FIXME: need better error handling */ + DMWARN("log presuspend failed"); + + /* + * Now that recovery is complete/stopped and the + * delayed bios are queued, we need to wait for + * the worker thread to complete. This way, + * we know that all of our I/O has been pushed. + */ + flush_workqueue(ms->kmirrord_wq); +} + +static void mirror_postsuspend(struct dm_target *ti) +{ + struct mirror_set *ms = ti->private; + struct dirty_log *log = ms->rh.log; + if (log->type->postsuspend && log->type->postsuspend(log)) /* FIXME: need better error handling */ - DMWARN("log suspend failed"); + DMWARN("log postsuspend failed"); } static void mirror_resume(struct dm_target *ti) { - struct mirror_set *ms = (struct mirror_set *) ti->private; + struct mirror_set *ms = ti->private; struct dirty_log *log = ms->rh.log; + + atomic_set(&ms->suspend, 0); if (log->type->resume && log->type->resume(log)) /* FIXME: need better error handling */ DMWARN("log resume failed"); rh_start_recovery(&ms->rh); } +/* + * device_status_char + * @m: mirror device/leg we want the status of + * + * We return one character representing the most severe error + * we have encountered. + * A => Alive - No failures + * D => Dead - A write failure occurred leaving mirror out-of-sync + * S => Sync - A sychronization failure occurred, mirror out-of-sync + * R => Read - A read failure occurred, mirror data unaffected + * + * Returns: <char> + */ +static char device_status_char(struct mirror *m) +{ + if (!atomic_read(&(m->error_count))) + return 'A'; + + return (test_bit(DM_RAID1_WRITE_ERROR, &(m->error_type))) ? 'D' : + (test_bit(DM_RAID1_SYNC_ERROR, &(m->error_type))) ? 'S' : + (test_bit(DM_RAID1_READ_ERROR, &(m->error_type))) ? 'R' : 'U'; +} + + static int mirror_status(struct dm_target *ti, status_type_t type, char *result, unsigned int maxlen) { unsigned int m, sz = 0; struct mirror_set *ms = (struct mirror_set *) ti->private; + struct dirty_log *log = ms->rh.log; + char buffer[ms->nr_mirrors + 1]; switch (type) { case STATUSTYPE_INFO: DMEMIT("%d ", ms->nr_mirrors); - for (m = 0; m < ms->nr_mirrors; m++) + for (m = 0; m < ms->nr_mirrors; m++) { DMEMIT("%s ", ms->mirror[m].dev->name); + buffer[m] = device_status_char(&(ms->mirror[m])); + } + buffer[m] = '\0'; - DMEMIT("%llu/%llu 0 ", - (unsigned long long)ms->rh.log->type-> - get_sync_count(ms->rh.log), - (unsigned long long)ms->nr_regions); + DMEMIT("%llu/%llu 1 %s ", + (unsigned long long)log->type->get_sync_count(ms->rh.log), + (unsigned long long)ms->nr_regions, buffer); - sz += ms->rh.log->type->status(ms->rh.log, type, result+sz, maxlen-sz); + sz += log->type->status(ms->rh.log, type, result+sz, maxlen-sz); break; case STATUSTYPE_TABLE: - sz = ms->rh.log->type->status(ms->rh.log, type, result, maxlen); + sz = log->type->status(ms->rh.log, type, result, maxlen); DMEMIT("%d", ms->nr_mirrors); for (m = 0; m < ms->nr_mirrors; m++) DMEMIT(" %s %llu", ms->mirror[m].dev->name, - (unsigned long long)ms->mirror[m].offset); + (unsigned long long)ms->mirror[m].offset); if (ms->features & DM_RAID1_HANDLE_ERRORS) DMEMIT(" 1 handle_errors"); @@ -1360,12 +1847,13 @@ static int mirror_status(struct dm_target *ti, status_type_t type, static struct target_type mirror_target = { .name = "mirror", - .version = {1, 0, 3}, + .version = {1, 0, 20}, .module = THIS_MODULE, .ctr = mirror_ctr, .dtr = mirror_dtr, .map = mirror_map, .end_io = mirror_end_io, + .presuspend = mirror_presuspend, .postsuspend = mirror_postsuspend, .resume = mirror_resume, .status = mirror_status, |