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Diffstat (limited to 'ANDROID_3.4.5/drivers/md/dm-raid1.c')
-rw-r--r--ANDROID_3.4.5/drivers/md/dm-raid1.c1470
1 files changed, 0 insertions, 1470 deletions
diff --git a/ANDROID_3.4.5/drivers/md/dm-raid1.c b/ANDROID_3.4.5/drivers/md/dm-raid1.c
deleted file mode 100644
index d039de83..00000000
--- a/ANDROID_3.4.5/drivers/md/dm-raid1.c
+++ /dev/null
@@ -1,1470 +0,0 @@
-/*
- * 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-bio-record.h"
-
-#include <linux/init.h>
-#include <linux/mempool.h>
-#include <linux/module.h>
-#include <linux/pagemap.h>
-#include <linux/slab.h>
-#include <linux/workqueue.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_RAID1_HANDLE_ERRORS 0x01
-#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
-
-static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
-
-/*-----------------------------------------------------------------
- * 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;
- unsigned long error_type;
- struct dm_dev *dev;
- sector_t offset;
-};
-
-struct mirror_set {
- struct dm_target *ti;
- struct list_head list;
-
- 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 nr_mirrors;
- struct mirror mirror[0];
-};
-
-static void wakeup_mirrord(void *context)
-{
- struct mirror_set *ms = context;
-
- queue_work(ms->kmirrord_wq, &ms->kmirrord_work);
-}
-
-static void delayed_wake_fn(unsigned long data)
-{
- struct mirror_set *ms = (struct mirror_set *) data;
-
- clear_bit(0, &ms->timer_pending);
- wakeup_mirrord(ms);
-}
-
-static void delayed_wake(struct mirror_set *ms)
-{
- if (test_and_set_bit(0, &ms->timer_pending))
- return;
-
- ms->timer.expires = jiffies + HZ / 5;
- ms->timer.data = (unsigned long) ms;
- ms->timer.function = delayed_wake_fn;
- add_timer(&ms->timer);
-}
-
-static void wakeup_all_recovery_waiters(void *context)
-{
- wake_up_all(&_kmirrord_recovery_stopped);
-}
-
-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)
- wakeup_mirrord(ms);
-}
-
-static void dispatch_bios(void *context, struct bio_list *bio_list)
-{
- struct mirror_set *ms = context;
- struct bio *bio;
-
- while ((bio = bio_list_pop(bio_list)))
- queue_bio(ms, bio, WRITE);
-}
-
-#define MIN_READ_RECORDS 20
-struct dm_raid1_read_record {
- struct mirror *m;
- struct dm_bio_details details;
-};
-
-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 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 *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 &ms->mirror[atomic_read(&ms->default_mirror)];
-}
-
-static void set_default_mirror(struct mirror *m)
-{
- struct mirror_set *ms = m->ms;
- struct mirror *m0 = &(ms->mirror[0]);
-
- 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
- *
- * 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;
-
- ms->leg_failure = 1;
-
- /*
- * 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 (!errors_handled(ms))
- 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;
- }
-
- 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_FLUSH,
- .mem.type = DM_IO_KMEM,
- .mem.ptr.addr = 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.
- *
- * When a mirror is first activated we may find that some regions
- * 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 long write_err,
- void *context)
-{
- struct dm_region *reg = context;
- struct mirror_set *ms = dm_rh_region_context(reg);
- int m, bit = 0;
-
- 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) {
- DMERR_LIMIT("Write error during recovery (error = 0x%lx)",
- 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++;
- }
- }
-
- dm_rh_recovery_end(reg, !(read_err || write_err));
-}
-
-static int recover(struct mirror_set *ms, struct dm_region *reg)
-{
- int r;
- 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 + 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 & (region_size - 1);
- if (!from.count)
- from.count = region_size;
- } else
- from.count = region_size;
-
- /* fill in the destinations */
- for (i = 0, dest = to; i < ms->nr_mirrors; i++) {
- if (&ms->mirror[i] == get_default_mirror(ms))
- continue;
-
- m = ms->mirror + i;
- dest->bdev = m->dev->bdev;
- dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
- dest->count = from.count;
- dest++;
- }
-
- /* hand to kcopyd */
- 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;
-
- /*
- * Start quiescing some regions.
- */
- dm_rh_recovery_prepare(ms->rh);
-
- /*
- * Copy any already quiesced regions.
- */
- while ((reg = dm_rh_recovery_start(ms->rh))) {
- r = recover(ms, reg);
- if (r)
- dm_rh_recovery_end(reg, 0);
- }
-
- /*
- * Update the in sync flag.
- */
- if (!ms->in_sync &&
- (log->type->get_sync_count(log) == ms->nr_regions)) {
- /* the sync is complete */
- dm_table_event(ms->ti->table);
- ms->in_sync = 1;
- }
-}
-
-/*-----------------------------------------------------------------
- * Reads
- *---------------------------------------------------------------*/
-static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)
-{
- 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 sector_t map_sector(struct mirror *m, struct bio *bio)
-{
- if (unlikely(!bio->bi_size))
- return 0;
- return m->offset + dm_target_offset(m->ms->ti, bio->bi_sector);
-}
-
-static void map_bio(struct mirror *m, struct bio *bio)
-{
- bio->bi_bdev = m->dev->bdev;
- 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)
-{
- region_t region;
- struct bio *bio;
- struct mirror *m;
-
- while ((bio = bio_list_pop(reads))) {
- 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 (likely(region_in_sync(ms, region, 1)))
- m = choose_mirror(ms, bio->bi_sector);
- else if (m && atomic_read(&m->error_count))
- m = NULL;
-
- if (likely(m))
- read_async_bio(m, bio);
- else
- bio_endio(bio, -EIO);
- }
-}
-
-/*-----------------------------------------------------------------
- * Writes.
- *
- * We do different things with the write io depending on the
- * state of the region that it's in:
- *
- * SYNC: increment pending, use kcopyd to write to *all* mirrors
- * RECOVERING: delay the io until recovery completes
- * NOSYNC: increment pending, just write to the default mirror
- *---------------------------------------------------------------*/
-
-
-static void write_callback(unsigned long error, void *context)
-{
- unsigned i, ret = 0;
- struct bio *bio = (struct bio *) context;
- struct mirror_set *ms;
- int should_wake = 0;
- unsigned long flags;
-
- ms = bio_get_m(bio)->ms;
- bio_set_m(bio, NULL);
-
- /*
- * NOTE: We don't decrement the pending count here,
- * instead it is done by the targets endio function.
- * This way we handle both writes to SYNC and NOSYNC
- * regions with the same code.
- */
- 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);
-
- /*
- * 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 dm_io_region io[ms->nr_mirrors], *dest = io;
- struct mirror *m;
- struct dm_io_request io_req = {
- .bi_rw = WRITE | (bio->bi_rw & WRITE_FLUSH_FUA),
- .mem.type = DM_IO_BVEC,
- .mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
- .notify.fn = write_callback,
- .notify.context = bio,
- .client = ms->io_client,
- };
-
- if (bio->bi_rw & REQ_DISCARD) {
- io_req.bi_rw |= REQ_DISCARD;
- io_req.mem.type = DM_IO_KMEM;
- io_req.mem.ptr.addr = NULL;
- }
-
- for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++)
- map_region(dest++, m, bio);
-
- /*
- * 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));
-
- 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;
-
- /*
- * Classify each write.
- */
- bio_list_init(&sync);
- bio_list_init(&nosync);
- bio_list_init(&recover);
- bio_list_init(&requeue);
-
- while ((bio = bio_list_pop(writes))) {
- if ((bio->bi_rw & REQ_FLUSH) ||
- (bio->bi_rw & REQ_DISCARD)) {
- 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 DM_RH_CLEAN:
- case DM_RH_DIRTY:
- this_list = &sync;
- break;
-
- case DM_RH_NOSYNC:
- this_list = &nosync;
- break;
-
- case DM_RH_RECOVERING:
- this_list = &recover;
- break;
- }
-
- bio_list_add(this_list, bio);
- }
-
- /*
- * 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).
- */
- 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) && 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)))
- do_write(ms, bio);
-
- while ((bio = bio_list_pop(&recover)))
- dm_rh_delay(ms->rh, bio);
-
- while ((bio = bio_list_pop(&nosync))) {
- 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);
- }
- }
-}
-
-static void do_failures(struct mirror_set *ms, struct bio_list *failures)
-{
- struct bio *bio;
-
- if (likely(!failures->head))
- return;
-
- /*
- * 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)
-{
- 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)
-{
- struct mirror_set *ms = container_of(work, struct mirror_set,
- kmirrord_work);
- struct bio_list reads, writes, failures;
- unsigned long flags;
-
- 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);
- bio_list_init(&ms->failures);
- spin_unlock_irqrestore(&ms->lock, flags);
-
- dm_rh_update_states(ms->rh, errors_handled(ms));
- do_recovery(ms);
- do_reads(ms, &reads);
- do_writes(ms, &writes);
- do_failures(ms, &failures);
-}
-
-/*-----------------------------------------------------------------
- * Target functions
- *---------------------------------------------------------------*/
-static struct mirror_set *alloc_context(unsigned int nr_mirrors,
- uint32_t region_size,
- struct dm_target *ti,
- struct dm_dirty_log *dl)
-{
- size_t len;
- struct mirror_set *ms = NULL;
-
- len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors);
-
- ms = kzalloc(len, GFP_KERNEL);
- if (!ms) {
- ti->error = "Cannot allocate mirror context";
- return NULL;
- }
-
- 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();
- if (IS_ERR(ms->io_client)) {
- ti->error = "Error creating dm_io client";
- mempool_destroy(ms->read_record_pool);
- kfree(ms);
- return NULL;
- }
-
- 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;
- }
-
- return ms;
-}
-
-static void free_context(struct mirror_set *ms, struct dm_target *ti,
- unsigned int m)
-{
- while (m--)
- dm_put_device(ti, ms->mirror[m].dev);
-
- dm_io_client_destroy(ms->io_client);
- dm_region_hash_destroy(ms->rh);
- mempool_destroy(ms->read_record_pool);
- kfree(ms);
-}
-
-static int get_mirror(struct mirror_set *ms, struct dm_target *ti,
- unsigned int mirror, char **argv)
-{
- unsigned long long offset;
- char dummy;
-
- if (sscanf(argv[1], "%llu%c", &offset, &dummy) != 1) {
- ti->error = "Invalid offset";
- return -EINVAL;
- }
-
- if (dm_get_device(ti, argv[0], dm_table_get_mode(ti->table),
- &ms->mirror[mirror].dev)) {
- ti->error = "Device lookup failure";
- return -ENXIO;
- }
-
- 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;
-}
-
-/*
- * Create dirty log: log_type #log_params <log_params>
- */
-static struct dm_dirty_log *create_dirty_log(struct dm_target *ti,
- unsigned argc, char **argv,
- unsigned *args_used)
-{
- unsigned param_count;
- struct dm_dirty_log *dl;
- char dummy;
-
- if (argc < 2) {
- ti->error = "Insufficient mirror log arguments";
- return NULL;
- }
-
- if (sscanf(argv[1], "%u%c", &param_count, &dummy) != 1) {
- ti->error = "Invalid mirror log argument count";
- return NULL;
- }
-
- *args_used = 2 + param_count;
-
- if (argc < *args_used) {
- ti->error = "Insufficient mirror log arguments";
- return NULL;
- }
-
- 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;
- }
-
- return dl;
-}
-
-static int parse_features(struct mirror_set *ms, unsigned argc, char **argv,
- unsigned *args_used)
-{
- unsigned num_features;
- struct dm_target *ti = ms->ti;
- char dummy;
-
- *args_used = 0;
-
- if (!argc)
- return 0;
-
- if (sscanf(argv[0], "%u%c", &num_features, &dummy) != 1) {
- ti->error = "Invalid number of features";
- return -EINVAL;
- }
-
- argc--;
- argv++;
- (*args_used)++;
-
- if (num_features > argc) {
- ti->error = "Not enough arguments to support feature count";
- return -EINVAL;
- }
-
- if (!strcmp("handle_errors", argv[0]))
- ms->features |= DM_RAID1_HANDLE_ERRORS;
- else {
- ti->error = "Unrecognised feature requested";
- return -EINVAL;
- }
-
- (*args_used)++;
-
- return 0;
-}
-
-/*
- * Construct a mirror mapping:
- *
- * log_type #log_params <log_params>
- * #mirrors [mirror_path offset]{2,}
- * [#features <features>]
- *
- * log_type is "core" or "disk"
- * #log_params is between 1 and 3
- *
- * If present, features must be "handle_errors".
- */
-static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv)
-{
- int r;
- unsigned int nr_mirrors, m, args_used;
- struct mirror_set *ms;
- struct dm_dirty_log *dl;
- char dummy;
-
- dl = create_dirty_log(ti, argc, argv, &args_used);
- if (!dl)
- return -EINVAL;
-
- argv += args_used;
- argc -= args_used;
-
- if (!argc || sscanf(argv[0], "%u%c", &nr_mirrors, &dummy) != 1 ||
- nr_mirrors < 2 || nr_mirrors > DM_KCOPYD_MAX_REGIONS + 1) {
- ti->error = "Invalid number of mirrors";
- dm_dirty_log_destroy(dl);
- return -EINVAL;
- }
-
- argv++, argc--;
-
- if (argc < nr_mirrors * 2) {
- ti->error = "Too few mirror arguments";
- dm_dirty_log_destroy(dl);
- return -EINVAL;
- }
-
- ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl);
- if (!ms) {
- dm_dirty_log_destroy(dl);
- return -ENOMEM;
- }
-
- /* Get the mirror parameter sets */
- for (m = 0; m < nr_mirrors; m++) {
- r = get_mirror(ms, ti, m, argv);
- if (r) {
- free_context(ms, ti, m);
- return r;
- }
- argv += 2;
- argc -= 2;
- }
-
- ti->private = ms;
- ti->split_io = dm_rh_get_region_size(ms->rh);
- ti->num_flush_requests = 1;
- ti->num_discard_requests = 1;
-
- ms->kmirrord_wq = alloc_workqueue("kmirrord",
- WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0);
- if (!ms->kmirrord_wq) {
- DMERR("couldn't start kmirrord");
- r = -ENOMEM;
- 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);
- if (r)
- goto err_destroy_wq;
-
- argv += args_used;
- argc -= args_used;
-
- /*
- * Any read-balancing addition depends on the
- * DM_RAID1_HANDLE_ERRORS flag being present.
- * This is because the decision to balance depends
- * on the sync state of a region. If the above
- * flag is not present, we ignore errors; and
- * the sync state may be inaccurate.
- */
-
- if (argc) {
- ti->error = "Too many mirror arguments";
- r = -EINVAL;
- goto err_destroy_wq;
- }
-
- ms->kcopyd_client = dm_kcopyd_client_create();
- if (IS_ERR(ms->kcopyd_client)) {
- r = PTR_ERR(ms->kcopyd_client);
- goto err_destroy_wq;
- }
-
- wakeup_mirrord(ms);
- return 0;
-
-err_destroy_wq:
- destroy_workqueue(ms->kmirrord_wq);
-err_free_context:
- free_context(ms, ti, ms->nr_mirrors);
- return r;
-}
-
-static void mirror_dtr(struct dm_target *ti)
-{
- struct mirror_set *ms = (struct mirror_set *) ti->private;
-
- del_timer_sync(&ms->timer);
- flush_workqueue(ms->kmirrord_wq);
- flush_work_sync(&ms->trigger_event);
- dm_kcopyd_client_destroy(ms->kcopyd_client);
- destroy_workqueue(ms->kmirrord_wq);
- free_context(ms, ti, ms->nr_mirrors);
-}
-
-/*
- * Mirror mapping function
- */
-static int mirror_map(struct dm_target *ti, struct bio *bio,
- union map_info *map_context)
-{
- int r, rw = bio_rw(bio);
- struct mirror *m;
- struct mirror_set *ms = ti->private;
- 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 = log->type->in_sync(log, dm_rh_bio_to_region(ms->rh, bio), 0);
- if (r < 0 && r != -EWOULDBLOCK)
- return r;
-
- /*
- * If region is not in-sync queue the bio.
- */
- if (!r || (r == -EWOULDBLOCK)) {
- if (rw == READA)
- return -EWOULDBLOCK;
-
- 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 (unlikely(!m))
- return -EIO;
-
- 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;
-}
-
-static int mirror_end_io(struct dm_target *ti, struct bio *bio,
- int error, union map_info *map_context)
-{
- int rw = bio_rw(bio);
- struct mirror_set *ms = (struct mirror_set *) ti->private;
- 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) {
- if (!(bio->bi_rw & REQ_FLUSH))
- dm_rh_dec(ms->rh, map_context->ll);
- return error;
- }
-
- if (error == -EOPNOTSUPP)
- goto out;
-
- if ((error == -EWOULDBLOCK) && (bio->bi_rw & REQ_RAHEAD))
- 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_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);
-
- /*
- * 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_event(_kmirrord_recovery_stopped,
- !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 postsuspend failed");
-}
-
-static void mirror_resume(struct dm_target *ti)
-{
- 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");
- 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++) {
- DMEMIT("%s ", ms->mirror[m].dev->name);
- buffer[m] = device_status_char(&(ms->mirror[m]));
- }
- buffer[m] = '\0';
-
- DMEMIT("%llu/%llu 1 %s ",
- (unsigned long long)log->type->get_sync_count(log),
- (unsigned long long)ms->nr_regions, buffer);
-
- sz += log->type->status(log, type, result+sz, maxlen-sz);
-
- break;
-
- case STATUSTYPE_TABLE:
- 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);
-
- 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, 12, 1},
- .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;
-
- _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");
- 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)
-{
- dm_unregister_target(&mirror_target);
- kmem_cache_destroy(_dm_raid1_read_record_cache);
-}
-
-/* Module hooks */
-module_init(dm_mirror_init);
-module_exit(dm_mirror_exit);
-
-MODULE_DESCRIPTION(DM_NAME " mirror target");
-MODULE_AUTHOR("Joe Thornber");
-MODULE_LICENSE("GPL");
generated by cgit (git 2.34.1) at 2025-07-08 09:53:57 +0000