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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-06 06:26:40 +07:00
5339fc2d47
Explicitly initialize bio lists instead of relying on kzalloc. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Takahiro Yasui <tyasui@redhat.com> Tested-by: Takahiro Yasui <tyasui@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
1453 lines
34 KiB
C
1453 lines
34 KiB
C
/*
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* Copyright (C) 2003 Sistina Software Limited.
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* Copyright (C) 2005-2008 Red Hat, Inc. All rights reserved.
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*
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* This file is released under the GPL.
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*/
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#include "dm-bio-record.h"
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#include <linux/init.h>
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#include <linux/mempool.h>
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#include <linux/module.h>
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#include <linux/pagemap.h>
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#include <linux/slab.h>
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#include <linux/workqueue.h>
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#include <linux/device-mapper.h>
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#include <linux/dm-io.h>
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#include <linux/dm-dirty-log.h>
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#include <linux/dm-kcopyd.h>
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#include <linux/dm-region-hash.h>
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#define DM_MSG_PREFIX "raid1"
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#define MAX_RECOVERY 1 /* Maximum number of regions recovered in parallel. */
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#define DM_IO_PAGES 64
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#define DM_KCOPYD_PAGES 64
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#define DM_RAID1_HANDLE_ERRORS 0x01
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#define errors_handled(p) ((p)->features & DM_RAID1_HANDLE_ERRORS)
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static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped);
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/*-----------------------------------------------------------------
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* Mirror set structures.
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*---------------------------------------------------------------*/
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enum dm_raid1_error {
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DM_RAID1_WRITE_ERROR,
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DM_RAID1_FLUSH_ERROR,
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DM_RAID1_SYNC_ERROR,
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DM_RAID1_READ_ERROR
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};
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struct mirror {
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struct mirror_set *ms;
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atomic_t error_count;
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unsigned long error_type;
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struct dm_dev *dev;
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sector_t offset;
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};
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struct mirror_set {
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struct dm_target *ti;
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struct list_head list;
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uint64_t features;
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spinlock_t lock; /* protects the lists */
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struct bio_list reads;
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struct bio_list writes;
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struct bio_list failures;
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struct bio_list holds; /* bios are waiting until suspend */
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struct dm_region_hash *rh;
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struct dm_kcopyd_client *kcopyd_client;
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struct dm_io_client *io_client;
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mempool_t *read_record_pool;
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/* recovery */
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region_t nr_regions;
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int in_sync;
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int log_failure;
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int leg_failure;
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atomic_t suspend;
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atomic_t default_mirror; /* Default mirror */
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struct workqueue_struct *kmirrord_wq;
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struct work_struct kmirrord_work;
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struct timer_list timer;
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unsigned long timer_pending;
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struct work_struct trigger_event;
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unsigned nr_mirrors;
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struct mirror mirror[0];
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};
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static void wakeup_mirrord(void *context)
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{
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struct mirror_set *ms = context;
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queue_work(ms->kmirrord_wq, &ms->kmirrord_work);
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}
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static void delayed_wake_fn(unsigned long data)
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{
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struct mirror_set *ms = (struct mirror_set *) data;
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clear_bit(0, &ms->timer_pending);
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wakeup_mirrord(ms);
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}
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static void delayed_wake(struct mirror_set *ms)
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{
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if (test_and_set_bit(0, &ms->timer_pending))
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return;
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ms->timer.expires = jiffies + HZ / 5;
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ms->timer.data = (unsigned long) ms;
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ms->timer.function = delayed_wake_fn;
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add_timer(&ms->timer);
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}
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static void wakeup_all_recovery_waiters(void *context)
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{
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wake_up_all(&_kmirrord_recovery_stopped);
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}
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static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw)
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{
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unsigned long flags;
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int should_wake = 0;
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struct bio_list *bl;
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bl = (rw == WRITE) ? &ms->writes : &ms->reads;
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spin_lock_irqsave(&ms->lock, flags);
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should_wake = !(bl->head);
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bio_list_add(bl, bio);
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spin_unlock_irqrestore(&ms->lock, flags);
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if (should_wake)
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wakeup_mirrord(ms);
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}
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static void dispatch_bios(void *context, struct bio_list *bio_list)
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{
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struct mirror_set *ms = context;
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struct bio *bio;
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while ((bio = bio_list_pop(bio_list)))
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queue_bio(ms, bio, WRITE);
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}
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#define MIN_READ_RECORDS 20
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struct dm_raid1_read_record {
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struct mirror *m;
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struct dm_bio_details details;
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};
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static struct kmem_cache *_dm_raid1_read_record_cache;
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/*
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* Every mirror should look like this one.
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*/
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#define DEFAULT_MIRROR 0
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/*
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* This is yucky. We squirrel the mirror struct away inside
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* bi_next for read/write buffers. This is safe since the bh
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* doesn't get submitted to the lower levels of block layer.
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*/
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static struct mirror *bio_get_m(struct bio *bio)
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{
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return (struct mirror *) bio->bi_next;
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}
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static void bio_set_m(struct bio *bio, struct mirror *m)
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{
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bio->bi_next = (struct bio *) m;
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}
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static struct mirror *get_default_mirror(struct mirror_set *ms)
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{
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return &ms->mirror[atomic_read(&ms->default_mirror)];
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}
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static void set_default_mirror(struct mirror *m)
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{
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struct mirror_set *ms = m->ms;
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struct mirror *m0 = &(ms->mirror[0]);
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atomic_set(&ms->default_mirror, m - m0);
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}
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static struct mirror *get_valid_mirror(struct mirror_set *ms)
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{
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struct mirror *m;
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for (m = ms->mirror; m < ms->mirror + ms->nr_mirrors; m++)
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if (!atomic_read(&m->error_count))
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return m;
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return NULL;
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}
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/* fail_mirror
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* @m: mirror device to fail
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* @error_type: one of the enum's, DM_RAID1_*_ERROR
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*
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* If errors are being handled, record the type of
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* error encountered for this device. If this type
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* of error has already been recorded, we can return;
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* otherwise, we must signal userspace by triggering
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* an event. Additionally, if the device is the
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* primary device, we must choose a new primary, but
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* only if the mirror is in-sync.
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*
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* This function must not block.
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*/
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static void fail_mirror(struct mirror *m, enum dm_raid1_error error_type)
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{
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struct mirror_set *ms = m->ms;
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struct mirror *new;
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ms->leg_failure = 1;
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/*
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* error_count is used for nothing more than a
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* simple way to tell if a device has encountered
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* errors.
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*/
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atomic_inc(&m->error_count);
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if (test_and_set_bit(error_type, &m->error_type))
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return;
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if (!errors_handled(ms))
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return;
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if (m != get_default_mirror(ms))
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goto out;
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if (!ms->in_sync) {
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/*
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* Better to issue requests to same failing device
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* than to risk returning corrupt data.
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*/
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DMERR("Primary mirror (%s) failed while out-of-sync: "
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"Reads may fail.", m->dev->name);
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goto out;
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}
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new = get_valid_mirror(ms);
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if (new)
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set_default_mirror(new);
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else
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DMWARN("All sides of mirror have failed.");
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out:
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schedule_work(&ms->trigger_event);
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}
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static int mirror_flush(struct dm_target *ti)
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{
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struct mirror_set *ms = ti->private;
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unsigned long error_bits;
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unsigned int i;
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struct dm_io_region io[ms->nr_mirrors];
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struct mirror *m;
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struct dm_io_request io_req = {
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.bi_rw = WRITE_BARRIER,
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.mem.type = DM_IO_KMEM,
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.mem.ptr.bvec = NULL,
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.client = ms->io_client,
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};
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for (i = 0, m = ms->mirror; i < ms->nr_mirrors; i++, m++) {
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io[i].bdev = m->dev->bdev;
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io[i].sector = 0;
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io[i].count = 0;
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}
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error_bits = -1;
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dm_io(&io_req, ms->nr_mirrors, io, &error_bits);
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if (unlikely(error_bits != 0)) {
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for (i = 0; i < ms->nr_mirrors; i++)
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if (test_bit(i, &error_bits))
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fail_mirror(ms->mirror + i,
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DM_RAID1_FLUSH_ERROR);
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return -EIO;
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}
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return 0;
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}
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/*-----------------------------------------------------------------
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* Recovery.
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*
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* When a mirror is first activated we may find that some regions
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* are in the no-sync state. We have to recover these by
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* recopying from the default mirror to all the others.
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*---------------------------------------------------------------*/
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static void recovery_complete(int read_err, unsigned long write_err,
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void *context)
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{
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struct dm_region *reg = context;
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struct mirror_set *ms = dm_rh_region_context(reg);
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int m, bit = 0;
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if (read_err) {
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/* Read error means the failure of default mirror. */
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DMERR_LIMIT("Unable to read primary mirror during recovery");
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fail_mirror(get_default_mirror(ms), DM_RAID1_SYNC_ERROR);
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}
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if (write_err) {
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DMERR_LIMIT("Write error during recovery (error = 0x%lx)",
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write_err);
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/*
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* Bits correspond to devices (excluding default mirror).
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* The default mirror cannot change during recovery.
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*/
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for (m = 0; m < ms->nr_mirrors; m++) {
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if (&ms->mirror[m] == get_default_mirror(ms))
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continue;
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if (test_bit(bit, &write_err))
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fail_mirror(ms->mirror + m,
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DM_RAID1_SYNC_ERROR);
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bit++;
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}
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}
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dm_rh_recovery_end(reg, !(read_err || write_err));
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}
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static int recover(struct mirror_set *ms, struct dm_region *reg)
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{
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int r;
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unsigned i;
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struct dm_io_region from, to[DM_KCOPYD_MAX_REGIONS], *dest;
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struct mirror *m;
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unsigned long flags = 0;
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region_t key = dm_rh_get_region_key(reg);
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sector_t region_size = dm_rh_get_region_size(ms->rh);
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/* fill in the source */
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m = get_default_mirror(ms);
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from.bdev = m->dev->bdev;
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from.sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
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if (key == (ms->nr_regions - 1)) {
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/*
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* The final region may be smaller than
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* region_size.
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*/
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from.count = ms->ti->len & (region_size - 1);
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if (!from.count)
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from.count = region_size;
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} else
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from.count = region_size;
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/* fill in the destinations */
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for (i = 0, dest = to; i < ms->nr_mirrors; i++) {
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if (&ms->mirror[i] == get_default_mirror(ms))
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continue;
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m = ms->mirror + i;
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dest->bdev = m->dev->bdev;
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dest->sector = m->offset + dm_rh_region_to_sector(ms->rh, key);
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dest->count = from.count;
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dest++;
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}
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/* hand to kcopyd */
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if (!errors_handled(ms))
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set_bit(DM_KCOPYD_IGNORE_ERROR, &flags);
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r = dm_kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to,
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flags, recovery_complete, reg);
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return r;
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}
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static void do_recovery(struct mirror_set *ms)
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{
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struct dm_region *reg;
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struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
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int r;
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/*
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* Start quiescing some regions.
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*/
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dm_rh_recovery_prepare(ms->rh);
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/*
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* Copy any already quiesced regions.
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*/
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while ((reg = dm_rh_recovery_start(ms->rh))) {
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r = recover(ms, reg);
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if (r)
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dm_rh_recovery_end(reg, 0);
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}
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/*
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* Update the in sync flag.
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*/
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if (!ms->in_sync &&
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(log->type->get_sync_count(log) == ms->nr_regions)) {
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/* the sync is complete */
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dm_table_event(ms->ti->table);
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ms->in_sync = 1;
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}
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}
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/*-----------------------------------------------------------------
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* Reads
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*---------------------------------------------------------------*/
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static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector)
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{
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struct mirror *m = get_default_mirror(ms);
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do {
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if (likely(!atomic_read(&m->error_count)))
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return m;
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if (m-- == ms->mirror)
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m += ms->nr_mirrors;
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} while (m != get_default_mirror(ms));
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return NULL;
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}
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static int default_ok(struct mirror *m)
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{
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struct mirror *default_mirror = get_default_mirror(m->ms);
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return !atomic_read(&default_mirror->error_count);
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}
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static int mirror_available(struct mirror_set *ms, struct bio *bio)
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{
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struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
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region_t region = dm_rh_bio_to_region(ms->rh, bio);
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if (log->type->in_sync(log, region, 0))
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return choose_mirror(ms, bio->bi_sector) ? 1 : 0;
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return 0;
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}
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/*
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* remap a buffer to a particular mirror.
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*/
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static sector_t map_sector(struct mirror *m, struct bio *bio)
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{
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if (unlikely(!bio->bi_size))
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return 0;
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return m->offset + (bio->bi_sector - m->ms->ti->begin);
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}
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static void map_bio(struct mirror *m, struct bio *bio)
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{
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bio->bi_bdev = m->dev->bdev;
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bio->bi_sector = map_sector(m, bio);
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}
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static void map_region(struct dm_io_region *io, struct mirror *m,
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struct bio *bio)
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{
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io->bdev = m->dev->bdev;
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io->sector = map_sector(m, bio);
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io->count = bio->bi_size >> 9;
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}
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static void hold_bio(struct mirror_set *ms, struct bio *bio)
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{
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/*
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* If device is suspended, complete the bio.
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*/
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if (atomic_read(&ms->suspend)) {
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if (dm_noflush_suspending(ms->ti))
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bio_endio(bio, DM_ENDIO_REQUEUE);
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else
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bio_endio(bio, -EIO);
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return;
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}
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|
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/*
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* Hold bio until the suspend is complete.
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*/
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spin_lock_irq(&ms->lock);
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bio_list_add(&ms->holds, bio);
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spin_unlock_irq(&ms->lock);
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}
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|
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/*-----------------------------------------------------------------
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* Reads
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*---------------------------------------------------------------*/
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static void read_callback(unsigned long error, void *context)
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{
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struct bio *bio = context;
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struct mirror *m;
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m = bio_get_m(bio);
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bio_set_m(bio, NULL);
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if (likely(!error)) {
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bio_endio(bio, 0);
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return;
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}
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fail_mirror(m, DM_RAID1_READ_ERROR);
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if (likely(default_ok(m)) || mirror_available(m->ms, bio)) {
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DMWARN_LIMIT("Read failure on mirror device %s. "
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"Trying alternative device.",
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m->dev->name);
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queue_bio(m->ms, bio, bio_rw(bio));
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return;
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}
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DMERR_LIMIT("Read failure on mirror device %s. Failing I/O.",
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m->dev->name);
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bio_endio(bio, -EIO);
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}
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|
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/* Asynchronous read. */
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static void read_async_bio(struct mirror *m, struct bio *bio)
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{
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struct dm_io_region io;
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struct dm_io_request io_req = {
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.bi_rw = READ,
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.mem.type = DM_IO_BVEC,
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.mem.ptr.bvec = bio->bi_io_vec + bio->bi_idx,
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.notify.fn = read_callback,
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.notify.context = bio,
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.client = m->ms->io_client,
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};
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|
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map_region(&io, m, bio);
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bio_set_m(bio, m);
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BUG_ON(dm_io(&io_req, 1, &io, NULL));
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}
|
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|
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static inline int region_in_sync(struct mirror_set *ms, region_t region,
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int may_block)
|
|
{
|
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int state = dm_rh_get_state(ms->rh, region, may_block);
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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_BARRIER),
|
|
.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,
|
|
};
|
|
|
|
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 (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 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)) {
|
|
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))
|
|
hold_bio(ms, bio);
|
|
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);
|
|
|
|
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 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(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;
|
|
}
|
|
|
|
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;
|
|
|
|
if (sscanf(argv[1], "%llu", &offset) != 1) {
|
|
ti->error = "Invalid offset";
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (dm_get_device(ti, argv[0], offset, ti->len,
|
|
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;
|
|
|
|
if (argc < 2) {
|
|
ti->error = "Insufficient mirror log arguments";
|
|
return NULL;
|
|
}
|
|
|
|
if (sscanf(argv[1], "%u", ¶m_count) != 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;
|
|
|
|
*args_used = 0;
|
|
|
|
if (!argc)
|
|
return 0;
|
|
|
|
if (sscanf(argv[0], "%u", &num_features) != 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;
|
|
|
|
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", &nr_mirrors) != 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;
|
|
|
|
ms->kmirrord_wq = create_singlethread_workqueue("kmirrord");
|
|
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;
|
|
}
|
|
|
|
r = dm_kcopyd_client_create(DM_KCOPYD_PAGES, &ms->kcopyd_client);
|
|
if (r)
|
|
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_scheduled_work();
|
|
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 (likely(!bio_empty_barrier(bio)))
|
|
dm_rh_dec(ms->rh, map_context->ll);
|
|
return error;
|
|
}
|
|
|
|
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_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);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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, 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;
|
|
|
|
_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");
|