/*
* Copyright (C) 2003 Sistina Software Limited.
+ * Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
-#include "dm.h"
-#include "dm-bio-list.h"
-#include "dm-io.h"
-#include "dm-log.h"
-#include "kcopyd.h"
+#include "dm-bio-record.h"
-#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/mempool.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
-#include <linux/time.h>
-#include <linux/vmalloc.h>
#include <linux/workqueue.h>
-#include <linux/log2.h>
-#include <linux/hardirq.h>
+#include <linux/device-mapper.h>
+#include <linux/dm-io.h>
+#include <linux/dm-dirty-log.h>
+#include <linux/dm-kcopyd.h>
+#include <linux/dm-region-hash.h>
#define DM_MSG_PREFIX "raid1"
+
+#define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */
#define DM_IO_PAGES 64
+#define DM_KCOPYD_PAGES 64
#define DM_RAID1_HANDLE_ERRORS 0x01
#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
/*-----------------------------------------------------------------
- * Region hash
- *
- * The mirror splits itself up into discrete regions. Each
- * region can be in one of three states: clean, dirty,
- * nosync. There is no need to put clean regions in the hash.
- *
- * In addition to being present in the hash table a region _may_
- * be present on one of three lists.
- *
- * clean_regions: Regions on this list have no io pending to
- * them, they are in sync, we are no longer interested in them,
- * they are dull. rh_update_states() will remove them from the
- * hash table.
- *
- * quiesced_regions: These regions have been spun down, ready
- * for recovery. rh_recovery_start() will remove regions from
- * this list and hand them to kmirrord, which will schedule the
- * recovery io with kcopyd.
- *
- * recovered_regions: Regions that kcopyd has successfully
- * recovered. rh_update_states() will now schedule any delayed
- * io, up the recovery_count, and remove the region from the
- * hash.
- *
- * There are 2 locks:
- * A rw spin lock 'hash_lock' protects just the hash table,
- * this is never held in write mode from interrupt context,
- * which I believe means that we only have to disable irqs when
- * doing a write lock.
- *
- * An ordinary spin lock 'region_lock' that protects the three
- * lists in the region_hash, with the 'state', 'list' and
- * 'bhs_delayed' fields of the regions. This is used from irq
- * context, so all other uses will have to suspend local irqs.
- *---------------------------------------------------------------*/
-struct mirror_set;
-struct region_hash {
- struct mirror_set *ms;
- uint32_t region_size;
- unsigned region_shift;
-
- /* holds persistent region state */
- struct dirty_log *log;
-
- /* hash table */
- rwlock_t hash_lock;
- mempool_t *region_pool;
- unsigned int mask;
- unsigned int nr_buckets;
- struct list_head *buckets;
-
- spinlock_t region_lock;
- atomic_t recovery_in_flight;
- struct semaphore recovery_count;
- struct list_head clean_regions;
- struct list_head quiesced_regions;
- struct list_head recovered_regions;
- struct list_head failed_recovered_regions;
-};
-
-enum {
- RH_CLEAN,
- RH_DIRTY,
- RH_NOSYNC,
- RH_RECOVERING
-};
-
-struct region {
- struct region_hash *rh; /* FIXME: can we get rid of this ? */
- region_t key;
- int state;
-
- struct list_head hash_list;
- struct list_head list;
-
- atomic_t pending;
- struct bio_list delayed_bios;
-};
-
-
-/*-----------------------------------------------------------------
* Mirror set structures.
*---------------------------------------------------------------*/
enum dm_raid1_error {
DM_RAID1_WRITE_ERROR,
+ DM_RAID1_FLUSH_ERROR,
DM_RAID1_SYNC_ERROR,
DM_RAID1_READ_ERROR
};
struct mirror {
struct mirror_set *ms;
atomic_t error_count;
- uint32_t error_type;
+ unsigned long error_type;
struct dm_dev *dev;
sector_t offset;
};
struct mirror_set {
struct dm_target *ti;
struct list_head list;
- struct region_hash rh;
- struct kcopyd_client *kcopyd_client;
+
uint64_t features;
spinlock_t lock; /* protects the lists */
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;
struct dm_io_client *io_client;
+ mempool_t *read_record_pool;
/* recovery */
region_t nr_regions;
int in_sync;
int log_failure;
+ int leg_failure;
+ atomic_t suspend;
atomic_t default_mirror; /* Default mirror */
struct workqueue_struct *kmirrord_wq;
struct work_struct kmirrord_work;
+ struct timer_list timer;
+ unsigned long timer_pending;
+
struct work_struct trigger_event;
- unsigned int nr_mirrors;
+ unsigned nr_mirrors;
struct mirror mirror[0];
};
-/*
- * Conversion fns
- */
-static inline region_t bio_to_region(struct region_hash *rh, struct bio *bio)
+static void wakeup_mirrord(void *context)
{
- return (bio->bi_sector - rh->ms->ti->begin) >> rh->region_shift;
-}
+ struct mirror_set *ms = context;
-static inline sector_t region_to_sector(struct region_hash *rh, region_t region)
-{
- return region << rh->region_shift;
-}
-
-static void wake(struct mirror_set *ms)
-{
queue_work(ms->kmirrord_wq, &ms->kmirrord_work);
}
-/* FIXME move this */
-static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw);
-
-#define MIN_REGIONS 64
-#define MAX_RECOVERY 1
-static int rh_init(struct region_hash *rh, struct mirror_set *ms,
- struct dirty_log *log, uint32_t region_size,
- region_t nr_regions)
+static void delayed_wake_fn(unsigned long data)
{
- unsigned int nr_buckets, max_buckets;
- size_t i;
-
- /*
- * Calculate a suitable number of buckets for our hash
- * table.
- */
- max_buckets = nr_regions >> 6;
- for (nr_buckets = 128u; nr_buckets < max_buckets; nr_buckets <<= 1)
- ;
- nr_buckets >>= 1;
-
- rh->ms = ms;
- rh->log = log;
- rh->region_size = region_size;
- rh->region_shift = ffs(region_size) - 1;
- rwlock_init(&rh->hash_lock);
- rh->mask = nr_buckets - 1;
- rh->nr_buckets = nr_buckets;
-
- rh->buckets = vmalloc(nr_buckets * sizeof(*rh->buckets));
- if (!rh->buckets) {
- DMERR("unable to allocate region hash memory");
- return -ENOMEM;
- }
-
- for (i = 0; i < nr_buckets; i++)
- INIT_LIST_HEAD(rh->buckets + i);
-
- spin_lock_init(&rh->region_lock);
- sema_init(&rh->recovery_count, 0);
- atomic_set(&rh->recovery_in_flight, 0);
- INIT_LIST_HEAD(&rh->clean_regions);
- INIT_LIST_HEAD(&rh->quiesced_regions);
- INIT_LIST_HEAD(&rh->recovered_regions);
- INIT_LIST_HEAD(&rh->failed_recovered_regions);
-
- rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS,
- sizeof(struct region));
- if (!rh->region_pool) {
- vfree(rh->buckets);
- rh->buckets = NULL;
- return -ENOMEM;
- }
+ struct mirror_set *ms = (struct mirror_set *) data;
- return 0;
+ clear_bit(0, &ms->timer_pending);
+ wakeup_mirrord(ms);
}
-static void rh_exit(struct region_hash *rh)
+static void delayed_wake(struct mirror_set *ms)
{
- unsigned int h;
- struct region *reg, *nreg;
-
- BUG_ON(!list_empty(&rh->quiesced_regions));
- for (h = 0; h < rh->nr_buckets; h++) {
- list_for_each_entry_safe(reg, nreg, rh->buckets + h, hash_list) {
- BUG_ON(atomic_read(®->pending));
- mempool_free(reg, rh->region_pool);
- }
- }
-
- if (rh->log)
- dm_destroy_dirty_log(rh->log);
- if (rh->region_pool)
- mempool_destroy(rh->region_pool);
- vfree(rh->buckets);
-}
-
-#define RH_HASH_MULT 2654435387U
-
-static inline unsigned int rh_hash(struct region_hash *rh, region_t region)
-{
- return (unsigned int) ((region * RH_HASH_MULT) >> 12) & rh->mask;
-}
-
-static struct region *__rh_lookup(struct region_hash *rh, region_t region)
-{
- struct region *reg;
-
- list_for_each_entry (reg, rh->buckets + rh_hash(rh, region), hash_list)
- if (reg->key == region)
- return reg;
-
- return NULL;
-}
-
-static void __rh_insert(struct region_hash *rh, struct region *reg)
-{
- unsigned int h = rh_hash(rh, reg->key);
- list_add(®->hash_list, rh->buckets + h);
-}
-
-static struct region *__rh_alloc(struct region_hash *rh, region_t region)
-{
- struct region *reg, *nreg;
-
- read_unlock(&rh->hash_lock);
- nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC);
- if (unlikely(!nreg))
- nreg = kmalloc(sizeof(struct region), GFP_NOIO);
- nreg->state = rh->log->type->in_sync(rh->log, region, 1) ?
- RH_CLEAN : RH_NOSYNC;
- nreg->rh = rh;
- nreg->key = region;
-
- INIT_LIST_HEAD(&nreg->list);
-
- atomic_set(&nreg->pending, 0);
- bio_list_init(&nreg->delayed_bios);
- write_lock_irq(&rh->hash_lock);
-
- reg = __rh_lookup(rh, region);
- if (reg)
- /* we lost the race */
- mempool_free(nreg, rh->region_pool);
-
- else {
- __rh_insert(rh, nreg);
- if (nreg->state == RH_CLEAN) {
- spin_lock(&rh->region_lock);
- list_add(&nreg->list, &rh->clean_regions);
- spin_unlock(&rh->region_lock);
- }
- reg = nreg;
- }
- write_unlock_irq(&rh->hash_lock);
- read_lock(&rh->hash_lock);
-
- return reg;
-}
-
-static inline struct region *__rh_find(struct region_hash *rh, region_t region)
-{
- struct region *reg;
-
- reg = __rh_lookup(rh, region);
- if (!reg)
- reg = __rh_alloc(rh, region);
-
- return reg;
-}
-
-static int rh_state(struct region_hash *rh, region_t region, int may_block)
-{
- int r;
- struct region *reg;
-
- read_lock(&rh->hash_lock);
- reg = __rh_lookup(rh, region);
- read_unlock(&rh->hash_lock);
-
- if (reg)
- return reg->state;
-
- /*
- * The region wasn't in the hash, so we fall back to the
- * dirty log.
- */
- r = rh->log->type->in_sync(rh->log, region, may_block);
-
- /*
- * Any error from the dirty log (eg. -EWOULDBLOCK) gets
- * taken as a RH_NOSYNC
- */
- return r == 1 ? RH_CLEAN : RH_NOSYNC;
-}
-
-static inline int rh_in_sync(struct region_hash *rh,
- region_t region, int may_block)
-{
- int state = rh_state(rh, region, may_block);
- return state == RH_CLEAN || state == RH_DIRTY;
-}
-
-static void dispatch_bios(struct mirror_set *ms, struct bio_list *bio_list)
-{
- struct bio *bio;
-
- while ((bio = bio_list_pop(bio_list))) {
- queue_bio(ms, bio, WRITE);
- }
-}
-
-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_bios(rh->ms, ®->delayed_bios);
- if (atomic_dec_and_test(&rh->recovery_in_flight))
- wake_up_all(&_kmirrord_recovery_stopped);
- up(&rh->recovery_count);
-}
-
-static void rh_update_states(struct region_hash *rh)
-{
- struct region *reg, *next;
-
- LIST_HEAD(clean);
- LIST_HEAD(recovered);
- LIST_HEAD(failed_recovered);
-
- /*
- * Quickly grab the lists.
- */
- write_lock_irq(&rh->hash_lock);
- spin_lock(&rh->region_lock);
- if (!list_empty(&rh->clean_regions)) {
- list_splice(&rh->clean_regions, &clean);
- INIT_LIST_HEAD(&rh->clean_regions);
-
- list_for_each_entry(reg, &clean, list)
- list_del(®->hash_list);
- }
-
- if (!list_empty(&rh->recovered_regions)) {
- list_splice(&rh->recovered_regions, &recovered);
- INIT_LIST_HEAD(&rh->recovered_regions);
-
- list_for_each_entry (reg, &recovered, list)
- list_del(®->hash_list);
- }
-
- if (!list_empty(&rh->failed_recovered_regions)) {
- list_splice(&rh->failed_recovered_regions, &failed_recovered);
- INIT_LIST_HEAD(&rh->failed_recovered_regions);
-
- list_for_each_entry(reg, &failed_recovered, list)
- list_del(®->hash_list);
- }
-
- spin_unlock(&rh->region_lock);
- write_unlock_irq(&rh->hash_lock);
-
- /*
- * All the regions on the recovered and clean lists have
- * now been pulled out of the system, so no need to do
- * any more locking.
- */
- list_for_each_entry_safe (reg, next, &recovered, list) {
- rh->log->type->clear_region(rh->log, reg->key);
- complete_resync_work(reg, 1);
- mempool_free(reg, rh->region_pool);
- }
-
- list_for_each_entry_safe(reg, next, &failed_recovered, list) {
- complete_resync_work(reg, errors_handled(rh->ms) ? 0 : 1);
- mempool_free(reg, rh->region_pool);
- }
-
- list_for_each_entry_safe(reg, next, &clean, list) {
- rh->log->type->clear_region(rh->log, reg->key);
- mempool_free(reg, rh->region_pool);
- }
-
- rh->log->type->flush(rh->log);
-}
-
-static void rh_inc(struct region_hash *rh, region_t region)
-{
- struct region *reg;
-
- read_lock(&rh->hash_lock);
- reg = __rh_find(rh, region);
-
- spin_lock_irq(&rh->region_lock);
- atomic_inc(®->pending);
-
- if (reg->state == RH_CLEAN) {
- reg->state = RH_DIRTY;
- list_del_init(®->list); /* take off the clean list */
- spin_unlock_irq(&rh->region_lock);
-
- rh->log->type->mark_region(rh->log, reg->key);
- } else
- spin_unlock_irq(&rh->region_lock);
-
+ if (test_and_set_bit(0, &ms->timer_pending))
+ return;
- read_unlock(&rh->hash_lock);
+ ms->timer.expires = jiffies + HZ / 5;
+ ms->timer.data = (unsigned long) ms;
+ ms->timer.function = delayed_wake_fn;
+ add_timer(&ms->timer);
}
-static void rh_inc_pending(struct region_hash *rh, struct bio_list *bios)
+static void wakeup_all_recovery_waiters(void *context)
{
- struct bio *bio;
-
- for (bio = bios->head; bio; bio = bio->bi_next)
- rh_inc(rh, bio_to_region(rh, bio));
+ wake_up_all(&_kmirrord_recovery_stopped);
}
-static void rh_dec(struct region_hash *rh, region_t region)
+static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw)
{
unsigned long flags;
- struct region *reg;
int should_wake = 0;
+ struct bio_list *bl;
- read_lock(&rh->hash_lock);
- reg = __rh_lookup(rh, region);
- read_unlock(&rh->hash_lock);
-
- spin_lock_irqsave(&rh->region_lock, flags);
- if (atomic_dec_and_test(®->pending)) {
- /*
- * There is no pending I/O for this region.
- * We can move the region to corresponding list for next action.
- * At this point, the region is not yet connected to any list.
- *
- * If the state is RH_NOSYNC, the region should be kept off
- * from clean list.
- * The hash entry for RH_NOSYNC will remain in memory
- * until the region is recovered or the map is reloaded.
- */
-
- /* do nothing for RH_NOSYNC */
- if (reg->state == RH_RECOVERING) {
- list_add_tail(®->list, &rh->quiesced_regions);
- } else if (reg->state == RH_DIRTY) {
- reg->state = RH_CLEAN;
- list_add(®->list, &rh->clean_regions);
- }
- should_wake = 1;
- }
- spin_unlock_irqrestore(&rh->region_lock, flags);
+ bl = (rw == WRITE) ? &ms->writes : &ms->reads;
+ spin_lock_irqsave(&ms->lock, flags);
+ should_wake = !(bl->head);
+ bio_list_add(bl, bio);
+ spin_unlock_irqrestore(&ms->lock, flags);
if (should_wake)
- wake(rh->ms);
-}
-
-/*
- * Starts quiescing a region in preparation for recovery.
- */
-static int __rh_recovery_prepare(struct region_hash *rh)
-{
- int r;
- struct region *reg;
- region_t region;
-
- /*
- * Ask the dirty log what's next.
- */
- r = rh->log->type->get_resync_work(rh->log, ®ion);
- if (r <= 0)
- return r;
-
- /*
- * Get this region, and start it quiescing by setting the
- * recovering flag.
- */
- read_lock(&rh->hash_lock);
- reg = __rh_find(rh, region);
- read_unlock(&rh->hash_lock);
-
- spin_lock_irq(&rh->region_lock);
- reg->state = RH_RECOVERING;
-
- /* Already quiesced ? */
- if (atomic_read(®->pending))
- list_del_init(®->list);
- else
- list_move(®->list, &rh->quiesced_regions);
-
- spin_unlock_irq(&rh->region_lock);
-
- return 1;
-}
-
-static void rh_recovery_prepare(struct region_hash *rh)
-{
- /* Extra reference to avoid race with rh_stop_recovery */
- atomic_inc(&rh->recovery_in_flight);
-
- while (!down_trylock(&rh->recovery_count)) {
- atomic_inc(&rh->recovery_in_flight);
- if (__rh_recovery_prepare(rh) <= 0) {
- atomic_dec(&rh->recovery_in_flight);
- up(&rh->recovery_count);
- break;
- }
- }
-
- /* Drop the extra reference */
- if (atomic_dec_and_test(&rh->recovery_in_flight))
- wake_up_all(&_kmirrord_recovery_stopped);
-}
-
-/*
- * Returns any quiesced regions.
- */
-static struct region *rh_recovery_start(struct region_hash *rh)
-{
- struct region *reg = NULL;
-
- spin_lock_irq(&rh->region_lock);
- if (!list_empty(&rh->quiesced_regions)) {
- reg = list_entry(rh->quiesced_regions.next,
- struct region, list);
- list_del_init(®->list); /* remove from the quiesced list */
- }
- spin_unlock_irq(&rh->region_lock);
-
- return reg;
+ wakeup_mirrord(ms);
}
-static void rh_recovery_end(struct region *reg, int success)
+static void dispatch_bios(void *context, struct bio_list *bio_list)
{
- struct region_hash *rh = reg->rh;
-
- spin_lock_irq(&rh->region_lock);
- if (success)
- list_add(®->list, ®->rh->recovered_regions);
- else {
- reg->state = RH_NOSYNC;
- list_add(®->list, ®->rh->failed_recovered_regions);
- }
- spin_unlock_irq(&rh->region_lock);
-
- wake(rh->ms);
-}
-
-static int rh_flush(struct region_hash *rh)
-{
- return rh->log->type->flush(rh->log);
-}
-
-static void rh_delay(struct region_hash *rh, struct bio *bio)
-{
- struct region *reg;
-
- read_lock(&rh->hash_lock);
- reg = __rh_find(rh, bio_to_region(rh, bio));
- bio_list_add(®->delayed_bios, bio);
- read_unlock(&rh->hash_lock);
-}
-
-static void rh_stop_recovery(struct region_hash *rh)
-{
- int i;
+ struct mirror_set *ms = context;
+ struct bio *bio;
- /* wait for any recovering regions */
- for (i = 0; i < MAX_RECOVERY; i++)
- down(&rh->recovery_count);
+ while ((bio = bio_list_pop(bio_list)))
+ queue_bio(ms, bio, WRITE);
}
-static void rh_start_recovery(struct region_hash *rh)
-{
- int i;
-
- for (i = 0; i < MAX_RECOVERY; i++)
- up(&rh->recovery_count);
+#define MIN_READ_RECORDS 20
+struct dm_raid1_read_record {
+ struct mirror *m;
+ struct dm_bio_details details;
+};
- wake(rh->ms);
-}
+static struct kmem_cache *_dm_raid1_read_record_cache;
/*
* 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_set *) bio->bi_next;
+ return (struct mirror *) bio->bi_next;
}
-static void bio_set_ms(struct bio *bio, struct mirror_set *ms)
+static void bio_set_m(struct bio *bio, struct mirror *m)
{
- bio->bi_next = (struct bio *) ms;
+ bio->bi_next = (struct bio *) m;
}
static struct mirror *get_default_mirror(struct mirror_set *ms)
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
struct mirror_set *ms = m->ms;
struct mirror *new;
- if (!errors_handled(ms))
- return;
+ ms->leg_failure = 1;
/*
* error_count is used for nothing more than a
if (test_and_set_bit(error_type, &m->error_type))
return;
+ if (!errors_handled(ms))
+ return;
+
if (m != get_default_mirror(ms))
goto out;
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.
*
* are in the no-sync state. We have to recover these by
* recopying from the default mirror to all the others.
*---------------------------------------------------------------*/
-static void recovery_complete(int read_err, unsigned int write_err,
+static void recovery_complete(int read_err, unsigned long write_err,
void *context)
{
- struct region *reg = (struct region *)context;
- struct mirror_set *ms = reg->rh->ms;
+ struct dm_region *reg = context;
+ struct mirror_set *ms = dm_rh_region_context(reg);
int m, bit = 0;
if (read_err) {
}
if (write_err) {
- DMERR_LIMIT("Write error during recovery (error = 0x%x)",
+ DMERR_LIMIT("Write error during recovery (error = 0x%lx)",
write_err);
/*
* Bits correspond to devices (excluding default mirror).
}
}
- rh_recovery_end(reg, !(read_err || write_err));
+ dm_rh_recovery_end(reg, !(read_err || write_err));
}
-static int recover(struct mirror_set *ms, struct region *reg)
+static int recover(struct mirror_set *ms, struct dm_region *reg)
{
int r;
- unsigned int i;
- struct io_region from, to[KCOPYD_MAX_REGIONS], *dest;
+ unsigned i;
+ struct dm_io_region from, to[DM_KCOPYD_MAX_REGIONS], *dest;
struct mirror *m;
unsigned long flags = 0;
+ region_t key = dm_rh_get_region_key(reg);
+ sector_t region_size = dm_rh_get_region_size(ms->rh);
/* fill in the source */
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)) {
+ from.sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
+ if (key == (ms->nr_regions - 1)) {
/*
* The final region may be smaller than
* region_size.
*/
- from.count = ms->ti->len & (reg->rh->region_size - 1);
+ from.count = ms->ti->len & (region_size - 1);
if (!from.count)
- from.count = reg->rh->region_size;
+ from.count = region_size;
} else
- from.count = reg->rh->region_size;
+ from.count = region_size;
/* fill in the destinations */
for (i = 0, dest = to; i < ms->nr_mirrors; i++) {
m = ms->mirror + i;
dest->bdev = m->dev->bdev;
- dest->sector = m->offset + region_to_sector(reg->rh, reg->key);
+ dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
dest->count = from.count;
dest++;
}
/* hand to kcopyd */
- set_bit(KCOPYD_IGNORE_ERROR, &flags);
- r = kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to, flags,
- recovery_complete, reg);
+ if (!errors_handled(ms))
+ set_bit(DM_KCOPYD_IGNORE_ERROR, &flags);
+
+ r = dm_kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to,
+ flags, recovery_complete, reg);
return r;
}
static void do_recovery(struct mirror_set *ms)
{
+ struct dm_region *reg;
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
int r;
- struct region *reg;
- struct dirty_log *log = ms->rh.log;
/*
* Start quiescing some regions.
*/
- rh_recovery_prepare(&ms->rh);
+ dm_rh_recovery_prepare(ms->rh);
/*
* Copy any already quiesced regions.
*/
- while ((reg = rh_recovery_start(&ms->rh))) {
+ while ((reg = dm_rh_recovery_start(ms->rh))) {
r = recover(ms, reg);
if (r)
- rh_recovery_end(reg, 0);
+ dm_rh_recovery_end(reg, 0);
}
/*
*---------------------------------------------------------------*/
static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)
{
- /* FIXME: add read balancing */
- return get_default_mirror(ms);
+ 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)
+{
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+ region_t region = dm_rh_bio_to_region(ms->rh, bio);
+
+ if (log->type->in_sync(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)
+{
+ if (unlikely(!bio->bi_size))
+ return 0;
+ 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 dm_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;
+}
+
+static void hold_bio(struct mirror_set *ms, struct bio *bio)
+{
+ /*
+ * Lock is required to avoid race condition during suspend
+ * process.
+ */
+ spin_lock_irq(&ms->lock);
+
+ if (atomic_read(&ms->suspend)) {
+ spin_unlock_irq(&ms->lock);
+
+ /*
+ * If device is suspended, complete the bio.
+ */
+ 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.
+ */
+ bio_list_add(&ms->holds, bio);
+ spin_unlock_irq(&ms->lock);
+}
+
+/*-----------------------------------------------------------------
+ * 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 dm_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);
+ BUG_ON(dm_io(&io_req, 1, &io, NULL));
+}
+
+static inline int region_in_sync(struct mirror_set *ms, region_t region,
+ int may_block)
+{
+ int state = dm_rh_get_state(ms->rh, region, may_block);
+ return state == DM_RH_CLEAN || state == DM_RH_DIRTY;
}
static void do_reads(struct mirror_set *ms, struct bio_list *reads)
struct mirror *m;
while ((bio = bio_list_pop(reads))) {
- region = bio_to_region(&ms->rh, bio);
+ region = dm_rh_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(region_in_sync(ms, region, 1)))
m = choose_mirror(ms, bio->bi_sector);
- else
- m = get_default_mirror(ms);
+ 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);
}
}
* 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 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,
* 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)
- wake(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)
{
unsigned int i;
- struct io_region io[KCOPYD_MAX_REGIONS+1];
+ 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,
.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);
+ BUG_ON(dm_io(&io_req, ms->nr_mirrors, io, NULL));
}
static void do_writes(struct mirror_set *ms, struct bio_list *writes)
int state;
struct bio *bio;
struct bio_list sync, nosync, recover, *this_list = NULL;
+ struct bio_list requeue;
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+ region_t region;
if (!writes->head)
return;
bio_list_init(&sync);
bio_list_init(&nosync);
bio_list_init(&recover);
+ bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
- state = rh_state(&ms->rh, bio_to_region(&ms->rh, bio), 1);
+ 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 &&
+ log->type->is_remote_recovering(log, region)) {
+ bio_list_add(&requeue, bio);
+ continue;
+ }
+
+ state = dm_rh_get_state(ms->rh, region, 1);
switch (state) {
- case RH_CLEAN:
- case RH_DIRTY:
+ case DM_RH_CLEAN:
+ case DM_RH_DIRTY:
this_list = &sync;
break;
- case RH_NOSYNC:
+ case DM_RH_NOSYNC:
this_list = &nosync;
break;
- case RH_RECOVERING:
+ case DM_RH_RECOVERING:
this_list = &recover;
break;
}
}
/*
+ * Add bios that are delayed due to remote recovery
+ * back on to the write queue
+ */
+ if (unlikely(requeue.head)) {
+ spin_lock_irq(&ms->lock);
+ bio_list_merge(&ms->writes, &requeue);
+ spin_unlock_irq(&ms->lock);
+ delayed_wake(ms);
+ }
+
+ /*
* Increment the pending counts for any regions that will
* be written to (writes to recover regions are going to
* be delayed).
*/
- rh_inc_pending(&ms->rh, &sync);
- rh_inc_pending(&ms->rh, &nosync);
- ms->log_failure = rh_flush(&ms->rh) ? 1 : 0;
+ dm_rh_inc_pending(ms->rh, &sync);
+ dm_rh_inc_pending(ms->rh, &nosync);
+
+ /*
+ * If the flush fails on a previous call and succeeds here,
+ * we must not reset the log_failure variable. We need
+ * userspace interaction to do that.
+ */
+ ms->log_failure = dm_rh_flush(ms->rh) ? 1 : ms->log_failure;
/*
* Dispatch io.
*/
- if (unlikely(ms->log_failure))
+ if (unlikely(ms->log_failure) && errors_handled(ms)) {
+ spin_lock_irq(&ms->lock);
+ bio_list_merge(&ms->failures, &sync);
+ spin_unlock_irq(&ms->lock);
+ wakeup_mirrord(ms);
+ } 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);
+ dm_rh_delay(ms->rh, bio);
while ((bio = bio_list_pop(&nosync))) {
- map_bio(ms, get_default_mirror(ms), bio);
- generic_make_request(bio);
+ if (unlikely(ms->leg_failure) && errors_handled(ms)) {
+ spin_lock_irq(&ms->lock);
+ bio_list_add(&ms->failures, bio);
+ spin_unlock_irq(&ms->lock);
+ wakeup_mirrord(ms);
+ } else {
+ map_bio(get_default_mirror(ms), bio);
+ generic_make_request(bio);
+ }
}
}
{
struct bio *bio;
- if (!failures->head)
+ if (likely(!failures->head))
return;
- while ((bio = bio_list_pop(failures)))
- __bio_mark_nosync(ms, bio, bio->bi_size, 0);
+ /*
+ * If the log has failed, unattempted writes are being
+ * 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
+ * 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.
+ */
+ while ((bio = bio_list_pop(failures))) {
+ if (!ms->log_failure) {
+ ms->in_sync = 0;
+ dm_rh_mark_nosync(ms->rh, bio);
+ }
+
+ /*
+ * 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);
+ else if (errors_handled(ms))
+ hold_bio(ms, bio);
+ else
+ bio_endio(bio, 0);
+ }
}
static void trigger_event(struct work_struct *work)
/*-----------------------------------------------------------------
* kmirrord
*---------------------------------------------------------------*/
-static int _do_mirror(struct work_struct *work)
+static void do_mirror(struct work_struct *work)
{
- struct mirror_set *ms =container_of(work, struct mirror_set,
- kmirrord_work);
+ struct mirror_set *ms = container_of(work, struct mirror_set,
+ kmirrord_work);
struct bio_list reads, writes, failures;
unsigned long flags;
bio_list_init(&ms->failures);
spin_unlock_irqrestore(&ms->lock, flags);
- rh_update_states(&ms->rh);
+ dm_rh_update_states(ms->rh, errors_handled(ms));
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();
+ dm_table_unplug_all(ms->ti->table);
}
-
/*-----------------------------------------------------------------
* Target functions
*---------------------------------------------------------------*/
static struct mirror_set *alloc_context(unsigned int nr_mirrors,
uint32_t region_size,
struct dm_target *ti,
- struct dirty_log *dl)
+ struct dm_dirty_log *dl)
{
size_t len;
struct mirror_set *ms = NULL;
- if (array_too_big(sizeof(*ms), sizeof(ms->mirror[0]), nr_mirrors))
- return NULL;
-
len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors);
ms = kzalloc(len, GFP_KERNEL);
}
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);
+ ms->read_record_pool = mempool_create_slab_pool(MIN_READ_RECORDS,
+ _dm_raid1_read_record_cache);
+
+ 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;
}
- if (rh_init(&ms->rh, ms, dl, region_size, ms->nr_regions)) {
+ ms->rh = dm_region_hash_create(ms, dispatch_bios, wakeup_mirrord,
+ wakeup_all_recovery_waiters,
+ ms->ti->begin, MAX_RECOVERY,
+ dl, region_size, ms->nr_regions);
+ if (IS_ERR(ms->rh)) {
ti->error = "Error creating dirty region hash";
dm_io_client_destroy(ms->io_client);
+ mempool_destroy(ms->read_record_pool);
kfree(ms);
return NULL;
}
dm_put_device(ti, ms->mirror[m].dev);
dm_io_client_destroy(ms->io_client);
- rh_exit(&ms->rh);
+ dm_region_hash_destroy(ms->rh);
+ mempool_destroy(ms->read_record_pool);
kfree(ms);
}
-static inline int _check_region_size(struct dm_target *ti, uint32_t size)
-{
- return !(size % (PAGE_SIZE >> 9) || !is_power_of_2(size) ||
- size > ti->len);
-}
-
static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
unsigned int mirror, char **argv)
{
return -EINVAL;
}
- if (dm_get_device(ti, argv[0], offset, ti->len,
- dm_table_get_mode(ti->table),
+ if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
&ms->mirror[mirror].dev)) {
ti->error = "Device lookup failure";
return -ENXIO;
/*
* Create dirty log: log_type #log_params <log_params>
*/
-static struct dirty_log *create_dirty_log(struct dm_target *ti,
- unsigned int argc, char **argv,
- unsigned int *args_used)
+static struct dm_dirty_log *create_dirty_log(struct dm_target *ti,
+ unsigned argc, char **argv,
+ unsigned *args_used)
{
- unsigned int param_count;
- struct dirty_log *dl;
+ unsigned param_count;
+ struct dm_dirty_log *dl;
if (argc < 2) {
ti->error = "Insufficient mirror log arguments";
return NULL;
}
- dl = dm_create_dirty_log(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;
}
- if (!_check_region_size(ti, dl->type->get_region_size(dl))) {
- ti->error = "Invalid region size";
- dm_destroy_dirty_log(dl);
- return NULL;
- }
-
return dl;
}
int r;
unsigned int nr_mirrors, m, args_used;
struct mirror_set *ms;
- struct dirty_log *dl;
+ struct dm_dirty_log *dl;
dl = create_dirty_log(ti, argc, argv, &args_used);
if (!dl)
argc -= args_used;
if (!argc || sscanf(argv[0], "%u", &nr_mirrors) != 1 ||
- nr_mirrors < 2 || nr_mirrors > KCOPYD_MAX_REGIONS + 1) {
+ nr_mirrors < 2 || nr_mirrors > DM_KCOPYD_MAX_REGIONS + 1) {
ti->error = "Invalid number of mirrors";
- dm_destroy_dirty_log(dl);
+ dm_dirty_log_destroy(dl);
return -EINVAL;
}
if (argc < nr_mirrors * 2) {
ti->error = "Too few mirror arguments";
- dm_destroy_dirty_log(dl);
+ dm_dirty_log_destroy(dl);
return -EINVAL;
}
ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl);
if (!ms) {
- dm_destroy_dirty_log(dl);
+ dm_dirty_log_destroy(dl);
return -ENOMEM;
}
}
ti->private = ms;
- ti->split_io = ms->rh.region_size;
+ 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) {
goto err_free_context;
}
INIT_WORK(&ms->kmirrord_work, do_mirror);
+ init_timer(&ms->timer);
+ ms->timer_pending = 0;
INIT_WORK(&ms->trigger_event, trigger_event);
r = parse_features(ms, argc, argv, &args_used);
goto err_destroy_wq;
}
- r = kcopyd_client_create(DM_IO_PAGES, &ms->kcopyd_client);
+ r = dm_kcopyd_client_create(DM_KCOPYD_PAGES, &ms->kcopyd_client);
if (r)
goto err_destroy_wq;
- wake(ms);
+ wakeup_mirrord(ms);
return 0;
err_destroy_wq:
{
struct mirror_set *ms = (struct mirror_set *) ti->private;
+ del_timer_sync(&ms->timer);
flush_workqueue(ms->kmirrord_wq);
- kcopyd_client_destroy(ms->kcopyd_client);
+ flush_scheduled_work();
+ dm_kcopyd_client_destroy(ms->kcopyd_client);
destroy_workqueue(ms->kmirrord_wq);
free_context(ms, ti, ms->nr_mirrors);
}
-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_irqsave(&ms->lock, flags);
- should_wake = !(bl->head);
- bio_list_add(bl, bio);
- spin_unlock_irqrestore(&ms->lock, flags);
-
- if (should_wake)
- wake(ms);
-}
-
/*
* Mirror mapping function
*/
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;
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
if (rw == WRITE) {
+ /* Save region for mirror_end_io() handler */
+ map_context->ll = dm_rh_bio_to_region(ms->rh, bio);
queue_bio(ms, bio, rw);
return DM_MAPIO_SUBMITTED;
}
- r = ms->rh.log->type->in_sync(ms->rh.log,
- bio_to_region(&ms->rh, bio), 0);
+ r = log->type->in_sync(log, dm_rh_bio_to_region(ms->rh, bio), 0);
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;
}
{
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) {
+ if (likely(!bio_empty_barrier(bio)))
+ dm_rh_dec(ms->rh, map_context->ll);
+ return error;
+ }
- return 0;
+ if (error == -EOPNOTSUPP)
+ goto out;
+
+ if ((error == -EWOULDBLOCK) && bio_rw_flagged(bio, BIO_RW_AHEAD))
+ 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.");
+ return -EIO;
+ }
+
+ m = read_record->m;
+
+ DMERR("Mirror read failed from %s. Trying alternative device.",
+ m->dev->name);
+
+ 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;
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+
+ struct bio_list holds;
+ struct bio *bio;
+
+ atomic_set(&ms->suspend, 1);
- rh_stop_recovery(&ms->rh);
+ /*
+ * Process bios in the hold list to start recovery waiting
+ * for bios in the hold list. After the process, no bio has
+ * a chance to be added in 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);
+
+ /*
+ * We must finish up all the work that we've
+ * generated (i.e. recovery work).
+ */
+ dm_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));
+ !dm_rh_recovery_in_flight(ms->rh));
+
+ 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 dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
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 dirty_log *log = ms->rh.log;
+ struct mirror_set *ms = ti->private;
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+
+ 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);
+ dm_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_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';
+}
+
+
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 dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+ 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(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(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(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");
return 0;
}
+static int mirror_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct mirror_set *ms = ti->private;
+ int ret = 0;
+ unsigned i;
+
+ for (i = 0; !ret && i < ms->nr_mirrors; i++)
+ ret = fn(ti, ms->mirror[i].dev,
+ ms->mirror[i].offset, ti->len, data);
+
+ return ret;
+}
+
static struct target_type mirror_target = {
.name = "mirror",
- .version = {1, 0, 3},
+ .version = {1, 12, 0},
.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,
+ .iterate_devices = mirror_iterate_devices,
};
static int __init dm_mirror_init(void)
{
int r;
- r = dm_dirty_log_init();
- if (r)
- return r;
+ _dm_raid1_read_record_cache = KMEM_CACHE(dm_raid1_read_record, 0);
+ if (!_dm_raid1_read_record_cache) {
+ DMERR("Can't allocate dm_raid1_read_record cache");
+ r = -ENOMEM;
+ goto bad_cache;
+ }
r = dm_register_target(&mirror_target);
if (r < 0) {
DMERR("Failed to register mirror target");
- dm_dirty_log_exit();
+ goto bad_target;
}
+ return 0;
+
+bad_target:
+ kmem_cache_destroy(_dm_raid1_read_record_cache);
+bad_cache:
return r;
}
static void __exit dm_mirror_exit(void)
{
- int r;
-
- r = dm_unregister_target(&mirror_target);
- if (r < 0)
- DMERR("unregister failed %d", r);
-
- dm_dirty_log_exit();
+ dm_unregister_target(&mirror_target);
+ kmem_cache_destroy(_dm_raid1_read_record_cache);
}
/* Module hooks */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff