diff options
Diffstat (limited to 'drivers/md/dm-raid1.c')
-rw-r--r-- | drivers/md/dm-raid1.c | 219 |
1 files changed, 156 insertions, 63 deletions
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c index cc9dc79b0784..ad779bd13aec 100644 --- a/drivers/md/dm-raid1.c +++ b/drivers/md/dm-raid1.c @@ -35,6 +35,7 @@ static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped); *---------------------------------------------------------------*/ enum dm_raid1_error { DM_RAID1_WRITE_ERROR, + DM_RAID1_FLUSH_ERROR, DM_RAID1_SYNC_ERROR, DM_RAID1_READ_ERROR }; @@ -57,6 +58,7 @@ struct mirror_set { struct bio_list reads; struct bio_list writes; struct bio_list failures; + struct bio_list holds; /* bios are waiting until suspend */ struct dm_region_hash *rh; struct dm_kcopyd_client *kcopyd_client; @@ -67,6 +69,7 @@ struct mirror_set { region_t nr_regions; int in_sync; int log_failure; + int leg_failure; atomic_t suspend; atomic_t default_mirror; /* Default mirror */ @@ -179,6 +182,17 @@ static void set_default_mirror(struct mirror *m) atomic_set(&ms->default_mirror, m - m0); } +static struct mirror *get_valid_mirror(struct mirror_set *ms) +{ + struct mirror *m; + + for (m = ms->mirror; m < ms->mirror + ms->nr_mirrors; m++) + if (!atomic_read(&m->error_count)) + return m; + + return NULL; +} + /* fail_mirror * @m: mirror device to fail * @error_type: one of the enum's, DM_RAID1_*_ERROR @@ -198,6 +212,8 @@ static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type) struct mirror_set *ms = m->ms; struct mirror *new; + ms->leg_failure = 1; + /* * error_count is used for nothing more than a * simple way to tell if a device has encountered @@ -224,19 +240,50 @@ static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type) 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)) + new = get_valid_mirror(ms); + if (new) + set_default_mirror(new); + else DMWARN("All sides of mirror have failed."); out: schedule_work(&ms->trigger_event); } +static int mirror_flush(struct dm_target *ti) +{ + struct mirror_set *ms = ti->private; + unsigned long error_bits; + + unsigned int i; + struct dm_io_region io[ms->nr_mirrors]; + struct mirror *m; + struct dm_io_request io_req = { + .bi_rw = WRITE_BARRIER, + .mem.type = DM_IO_KMEM, + .mem.ptr.bvec = NULL, + .client = ms->io_client, + }; + + for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) { + io[i].bdev = m->dev->bdev; + io[i].sector = 0; + io[i].count = 0; + } + + error_bits = -1; + dm_io(&io_req, ms->nr_mirrors, io, &error_bits); + if (unlikely(error_bits != 0)) { + for (i = 0; i < ms->nr_mirrors; i++) + if (test_bit(i, &error_bits)) + fail_mirror(ms->mirror + i, + DM_RAID1_FLUSH_ERROR); + return -EIO; + } + + return 0; +} + /*----------------------------------------------------------------- * Recovery. * @@ -396,6 +443,8 @@ static int mirror_available(struct mirror_set *ms, struct bio *bio) */ static sector_t map_sector(struct mirror *m, struct bio *bio) { + if (unlikely(!bio->bi_size)) + return 0; return m->offset + (bio->bi_sector - m->ms->ti->begin); } @@ -413,6 +462,27 @@ static void map_region(struct dm_io_region *io, struct mirror *m, io->count = bio->bi_size >> 9; } +static void hold_bio(struct mirror_set *ms, struct bio *bio) +{ + /* + * If device is suspended, complete the bio. + */ + if (atomic_read(&ms->suspend)) { + if (dm_noflush_suspending(ms->ti)) + bio_endio(bio, DM_ENDIO_REQUEUE); + else + bio_endio(bio, -EIO); + return; + } + + /* + * Hold bio until the suspend is complete. + */ + spin_lock_irq(&ms->lock); + bio_list_add(&ms->holds, bio); + spin_unlock_irq(&ms->lock); +} + /*----------------------------------------------------------------- * Reads *---------------------------------------------------------------*/ @@ -511,7 +581,6 @@ static void write_callback(unsigned long error, void *context) unsigned i, ret = 0; struct bio *bio = (struct bio *) context; struct mirror_set *ms; - int uptodate = 0; int should_wake = 0; unsigned long flags; @@ -524,36 +593,27 @@ 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; + if (likely(!error)) { + bio_endio(bio, ret); + return; + } 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 (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)) { - /* - * Need to raise event. Since raising - * events can block, we need to do it in - * the main thread. - */ - 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) - wakeup_mirrord(ms); - return; - } -out: - bio_endio(bio, ret); + /* + * Need to raise event. Since raising + * events can block, we need to do it in + * the main thread. + */ + 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) + wakeup_mirrord(ms); } static void do_write(struct mirror_set *ms, struct bio *bio) @@ -562,7 +622,7 @@ static void do_write(struct mirror_set *ms, struct bio *bio) struct dm_io_region io[ms->nr_mirrors], *dest = io; struct mirror *m; struct dm_io_request io_req = { - .bi_rw = WRITE, + .bi_rw = WRITE | (bio->bi_rw & WRITE_BARRIER), .mem.type = DM_IO_BVEC, .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx, .notify.fn = write_callback, @@ -603,6 +663,11 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes) bio_list_init(&requeue); while ((bio = bio_list_pop(writes))) { + if (unlikely(bio_empty_barrier(bio))) { + bio_list_add(&sync, bio); + continue; + } + region = dm_rh_bio_to_region(ms->rh, bio); if (log->type->is_remote_recovering && @@ -672,8 +737,12 @@ static void do_writes(struct mirror_set *ms, struct bio_list *writes) dm_rh_delay(ms->rh, bio); while ((bio = bio_list_pop(&nosync))) { - map_bio(get_default_mirror(ms), bio); - generic_make_request(bio); + if (unlikely(ms->leg_failure) && errors_handled(ms)) + hold_bio(ms, bio); + else { + map_bio(get_default_mirror(ms), bio); + generic_make_request(bio); + } } } @@ -681,20 +750,12 @@ 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))) { - ms->in_sync = 0; - dm_rh_mark_nosync(ms->rh, bio, bio->bi_size, 0); - } + if (likely(!failures->head)) return; - } /* * If the log has failed, unattempted writes are being - * put on the failures list. We can't issue those writes + * put on the holds 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 @@ -709,23 +770,27 @@ static void do_failures(struct mirror_set *ms, struct bio_list *failures) * 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; - } + while ((bio = bio_list_pop(failures))) { + if (!ms->log_failure) { + ms->in_sync = 0; + dm_rh_mark_nosync(ms->rh, bio); + } - if (atomic_read(&ms->suspend)) { - while ((bio = bio_list_pop(failures))) + /* + * If all the legs are dead, fail the I/O. + * If we have been told to handle errors, hold the bio + * and wait for userspace to deal with the problem. + * Otherwise pretend that the I/O succeeded. (This would + * be wrong if the failed leg returned after reboot and + * got replicated back to the good legs.) + */ + if (!get_valid_mirror(ms)) bio_endio(bio, -EIO); - return; + else if (errors_handled(ms)) + hold_bio(ms, bio); + else + bio_endio(bio, 0); } - - spin_lock_irq(&ms->lock); - bio_list_merge(&ms->failures, failures); - spin_unlock_irq(&ms->lock); - - delayed_wake(ms); } static void trigger_event(struct work_struct *work) @@ -784,12 +849,17 @@ static struct mirror_set *alloc_context(unsigned int nr_mirrors, } spin_lock_init(&ms->lock); + bio_list_init(&ms->reads); + bio_list_init(&ms->writes); + bio_list_init(&ms->failures); + bio_list_init(&ms->holds); ms->ti = ti; ms->nr_mirrors = nr_mirrors; ms->nr_regions = dm_sector_div_up(ti->len, region_size); ms->in_sync = 0; ms->log_failure = 0; + ms->leg_failure = 0; atomic_set(&ms->suspend, 0); atomic_set(&ms->default_mirror, DEFAULT_MIRROR); @@ -889,7 +959,8 @@ static struct dm_dirty_log *create_dirty_log(struct dm_target *ti, return NULL; } - dl = dm_dirty_log_create(argv[0], ti, param_count, argv + 2); + dl = dm_dirty_log_create(argv[0], ti, mirror_flush, param_count, + argv + 2); if (!dl) { ti->error = "Error creating mirror dirty log"; return NULL; @@ -995,6 +1066,7 @@ static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv) ti->private = ms; ti->split_io = dm_rh_get_region_size(ms->rh); + ti->num_flush_requests = 1; ms->kmirrord_wq = create_singlethread_workqueue("kmirrord"); if (!ms->kmirrord_wq) { @@ -1122,7 +1194,8 @@ static int mirror_end_io(struct dm_target *ti, struct bio *bio, * We need to dec pending if this was a write. */ if (rw == WRITE) { - dm_rh_dec(ms->rh, map_context->ll); + if (likely(!bio_empty_barrier(bio))) + dm_rh_dec(ms->rh, map_context->ll); return error; } @@ -1180,6 +1253,9 @@ static void mirror_presuspend(struct dm_target *ti) struct mirror_set *ms = (struct mirror_set *) ti->private; struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh); + struct bio_list holds; + struct bio *bio; + atomic_set(&ms->suspend, 1); /* @@ -1202,6 +1278,22 @@ static void mirror_presuspend(struct dm_target *ti) * we know that all of our I/O has been pushed. */ flush_workqueue(ms->kmirrord_wq); + + /* + * Now set ms->suspend is set and the workqueue flushed, no more + * entries can be added to ms->hold list, so process it. + * + * Bios can still arrive concurrently with or after this + * presuspend function, but they cannot join the hold list + * because ms->suspend is set. + */ + spin_lock_irq(&ms->lock); + holds = ms->holds; + bio_list_init(&ms->holds); + spin_unlock_irq(&ms->lock); + + while ((bio = bio_list_pop(&holds))) + hold_bio(ms, bio); } static void mirror_postsuspend(struct dm_target *ti) @@ -1244,7 +1336,8 @@ 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' : + return (test_bit(DM_RAID1_FLUSH_ERROR, &(m->error_type))) ? 'F' : + (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'; } |