diff options
| -rw-r--r-- | Documentation/device-mapper/cache.txt | 11 | ||||
| -rw-r--r-- | Documentation/device-mapper/thin-provisioning.txt | 34 | ||||
| -rw-r--r-- | drivers/md/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/md/dm-cache-policy-mq.c | 4 | ||||
| -rw-r--r-- | drivers/md/dm-snap-persistent.c | 3 | ||||
| -rw-r--r-- | drivers/md/dm-thin-metadata.c | 37 | ||||
| -rw-r--r-- | drivers/md/dm-thin-metadata.h | 11 | ||||
| -rw-r--r-- | drivers/md/dm-thin.c | 304 | ||||
| -rw-r--r-- | drivers/md/persistent-data/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/md/persistent-data/dm-space-map-metadata.c | 113 |
10 files changed, 425 insertions, 112 deletions
diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt index e6b72d3..68c0f51 100644 --- a/Documentation/device-mapper/cache.txt +++ b/Documentation/device-mapper/cache.txt @@ -124,12 +124,11 @@ the default being 204800 sectors (or 100MB). Updating on-disk metadata ------------------------- -On-disk metadata is committed every time a REQ_SYNC or REQ_FUA bio is -written. If no such requests are made then commits will occur every -second. This means the cache behaves like a physical disk that has a -write cache (the same is true of the thin-provisioning target). If -power is lost you may lose some recent writes. The metadata should -always be consistent in spite of any crash. +On-disk metadata is committed every time a FLUSH or FUA bio is written. +If no such requests are made then commits will occur every second. This +means the cache behaves like a physical disk that has a volatile write +cache. If power is lost you may lose some recent writes. The metadata +should always be consistent in spite of any crash. The 'dirty' state for a cache block changes far too frequently for us to keep updating it on the fly. So we treat it as a hint. In normal diff --git a/Documentation/device-mapper/thin-provisioning.txt b/Documentation/device-mapper/thin-provisioning.txt index 8a7a3d4..05a27e9 100644 --- a/Documentation/device-mapper/thin-provisioning.txt +++ b/Documentation/device-mapper/thin-provisioning.txt @@ -116,6 +116,35 @@ Resuming a device with a new table itself triggers an event so the userspace daemon can use this to detect a situation where a new table already exceeds the threshold. +A low water mark for the metadata device is maintained in the kernel and +will trigger a dm event if free space on the metadata device drops below +it. + +Updating on-disk metadata +------------------------- + +On-disk metadata is committed every time a FLUSH or FUA bio is written. +If no such requests are made then commits will occur every second. This +means the thin-provisioning target behaves like a physical disk that has +a volatile write cache. If power is lost you may lose some recent +writes. The metadata should always be consistent in spite of any crash. + +If data space is exhausted the pool will either error or queue IO +according to the configuration (see: error_if_no_space). If metadata +space is exhausted or a metadata operation fails: the pool will error IO +until the pool is taken offline and repair is performed to 1) fix any +potential inconsistencies and 2) clear the flag that imposes repair. +Once the pool's metadata device is repaired it may be resized, which +will allow the pool to return to normal operation. Note that if a pool +is flagged as needing repair, the pool's data and metadata devices +cannot be resized until repair is performed. It should also be noted +that when the pool's metadata space is exhausted the current metadata +transaction is aborted. Given that the pool will cache IO whose +completion may have already been acknowledged to upper IO layers +(e.g. filesystem) it is strongly suggested that consistency checks +(e.g. fsck) be performed on those layers when repair of the pool is +required. + Thin provisioning ----------------- @@ -258,10 +287,9 @@ ii) Status should register for the event and then check the target's status. held metadata root: - The location, in sectors, of the metadata root that has been + The location, in blocks, of the metadata root that has been 'held' for userspace read access. '-' indicates there is no - held root. This feature is not yet implemented so '-' is - always returned. + held root. discard_passdown|no_discard_passdown Whether or not discards are actually being passed down to the diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig index 9a06fe8..95ad936 100644 --- a/drivers/md/Kconfig +++ b/drivers/md/Kconfig @@ -254,16 +254,6 @@ config DM_THIN_PROVISIONING ---help--- Provides thin provisioning and snapshots that share a data store. -config DM_DEBUG_BLOCK_STACK_TRACING - boolean "Keep stack trace of persistent data block lock holders" - depends on STACKTRACE_SUPPORT && DM_PERSISTENT_DATA - select STACKTRACE - ---help--- - Enable this for messages that may help debug problems with the - block manager locking used by thin provisioning and caching. - - If unsure, say N. - config DM_CACHE tristate "Cache target (EXPERIMENTAL)" depends on BLK_DEV_DM diff --git a/drivers/md/dm-cache-policy-mq.c b/drivers/md/dm-cache-policy-mq.c index 1e018e9..0e385e4 100644 --- a/drivers/md/dm-cache-policy-mq.c +++ b/drivers/md/dm-cache-policy-mq.c @@ -872,7 +872,7 @@ static void mq_destroy(struct dm_cache_policy *p) { struct mq_policy *mq = to_mq_policy(p); - kfree(mq->table); + vfree(mq->table); epool_exit(&mq->cache_pool); epool_exit(&mq->pre_cache_pool); kfree(mq); @@ -1245,7 +1245,7 @@ static struct dm_cache_policy *mq_create(dm_cblock_t cache_size, mq->nr_buckets = next_power(from_cblock(cache_size) / 2, 16); mq->hash_bits = ffs(mq->nr_buckets) - 1; - mq->table = kzalloc(sizeof(*mq->table) * mq->nr_buckets, GFP_KERNEL); + mq->table = vzalloc(sizeof(*mq->table) * mq->nr_buckets); if (!mq->table) goto bad_alloc_table; diff --git a/drivers/md/dm-snap-persistent.c b/drivers/md/dm-snap-persistent.c index afc3d01..d6e8817 100644 --- a/drivers/md/dm-snap-persistent.c +++ b/drivers/md/dm-snap-persistent.c @@ -546,6 +546,9 @@ static int read_exceptions(struct pstore *ps, r = insert_exceptions(ps, area, callback, callback_context, &full); + if (!full) + memcpy(ps->area, area, ps->store->chunk_size << SECTOR_SHIFT); + dm_bufio_release(bp); dm_bufio_forget(client, chunk); diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c index baa87ff..fb9efc8 100644 --- a/drivers/md/dm-thin-metadata.c +++ b/drivers/md/dm-thin-metadata.c @@ -76,7 +76,7 @@ #define THIN_SUPERBLOCK_MAGIC 27022010 #define THIN_SUPERBLOCK_LOCATION 0 -#define THIN_VERSION 1 +#define THIN_VERSION 2 #define THIN_METADATA_CACHE_SIZE 64 #define SECTOR_TO_BLOCK_SHIFT 3 @@ -1755,3 +1755,38 @@ int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, return r; } + +int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd) +{ + int r; + struct dm_block *sblock; + struct thin_disk_superblock *disk_super; + + down_write(&pmd->root_lock); + pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG; + + r = superblock_lock(pmd, &sblock); + if (r) { + DMERR("couldn't read superblock"); + goto out; + } + + disk_super = dm_block_data(sblock); + disk_super->flags = cpu_to_le32(pmd->flags); + + dm_bm_unlock(sblock); +out: + up_write(&pmd->root_lock); + return r; +} + +bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd) +{ + bool needs_check; + + down_read(&pmd->root_lock); + needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG; + up_read(&pmd->root_lock); + + return needs_check; +} diff --git a/drivers/md/dm-thin-metadata.h b/drivers/md/dm-thin-metadata.h index 82ea384..e3c857d 100644 --- a/drivers/md/dm-thin-metadata.h +++ b/drivers/md/dm-thin-metadata.h @@ -25,6 +25,11 @@ /*----------------------------------------------------------------*/ +/* + * Thin metadata superblock flags. + */ +#define THIN_METADATA_NEEDS_CHECK_FLAG (1 << 0) + struct dm_pool_metadata; struct dm_thin_device; @@ -202,6 +207,12 @@ int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, dm_sm_threshold_fn fn, void *context); +/* + * Updates the superblock immediately. + */ +int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd); +bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd); + /*----------------------------------------------------------------*/ #endif diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 7e84bac..be70d38 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -130,10 +130,11 @@ static void build_virtual_key(struct dm_thin_device *td, dm_block_t b, struct dm_thin_new_mapping; /* - * The pool runs in 3 modes. Ordered in degraded order for comparisons. + * The pool runs in 4 modes. Ordered in degraded order for comparisons. */ enum pool_mode { PM_WRITE, /* metadata may be changed */ + PM_OUT_OF_DATA_SPACE, /* metadata may be changed, though data may not be allocated */ PM_READ_ONLY, /* metadata may not be changed */ PM_FAIL, /* all I/O fails */ }; @@ -198,7 +199,6 @@ struct pool { }; static enum pool_mode get_pool_mode(struct pool *pool); -static void out_of_data_space(struct pool *pool); static void metadata_operation_failed(struct pool *pool, const char *op, int r); /* @@ -226,6 +226,7 @@ struct thin_c { struct pool *pool; struct dm_thin_device *td; + bool requeue_mode:1; }; /*----------------------------------------------------------------*/ @@ -369,14 +370,18 @@ struct dm_thin_endio_hook { struct dm_thin_new_mapping *overwrite_mapping; }; -static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master) +static void requeue_bio_list(struct thin_c *tc, struct bio_list *master) { struct bio *bio; struct bio_list bios; + unsigned long flags; bio_list_init(&bios); + + spin_lock_irqsave(&tc->pool->lock, flags); bio_list_merge(&bios, master); bio_list_init(master); + spin_unlock_irqrestore(&tc->pool->lock, flags); while ((bio = bio_list_pop(&bios))) { struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); @@ -391,12 +396,26 @@ static void __requeue_bio_list(struct thin_c *tc, struct bio_list *master) static void requeue_io(struct thin_c *tc) { struct pool *pool = tc->pool; + + requeue_bio_list(tc, &pool->deferred_bios); + requeue_bio_list(tc, &pool->retry_on_resume_list); +} + +static void error_retry_list(struct pool *pool) +{ + struct bio *bio; unsigned long flags; + struct bio_list bios; + + bio_list_init(&bios); spin_lock_irqsave(&pool->lock, flags); - __requeue_bio_list(tc, &pool->deferred_bios); - __requeue_bio_list(tc, &pool->retry_on_resume_list); + bio_list_merge(&bios, &pool->retry_on_resume_list); + bio_list_init(&pool->retry_on_resume_list); spin_unlock_irqrestore(&pool->lock, flags); + + while ((bio = bio_list_pop(&bios))) + bio_io_error(bio); } /* @@ -925,13 +944,15 @@ static void check_low_water_mark(struct pool *pool, dm_block_t free_blocks) } } +static void set_pool_mode(struct pool *pool, enum pool_mode new_mode); + static int alloc_data_block(struct thin_c *tc, dm_block_t *result) { int r; dm_block_t free_blocks; struct pool *pool = tc->pool; - if (get_pool_mode(pool) != PM_WRITE) + if (WARN_ON(get_pool_mode(pool) != PM_WRITE)) return -EINVAL; r = dm_pool_get_free_block_count(pool->pmd, &free_blocks); @@ -958,7 +979,7 @@ static int alloc_data_block(struct thin_c *tc, dm_block_t *result) } if (!free_blocks) { - out_of_data_space(pool); + set_pool_mode(pool, PM_OUT_OF_DATA_SPACE); return -ENOSPC; } } @@ -988,15 +1009,32 @@ static void retry_on_resume(struct bio *bio) spin_unlock_irqrestore(&pool->lock, flags); } -static void handle_unserviceable_bio(struct pool *pool, struct bio *bio) +static bool should_error_unserviceable_bio(struct pool *pool) { - /* - * When pool is read-only, no cell locking is needed because - * nothing is changing. - */ - WARN_ON_ONCE(get_pool_mode(pool) != PM_READ_ONLY); + enum pool_mode m = get_pool_mode(pool); + + switch (m) { + case PM_WRITE: + /* Shouldn't get here */ + DMERR_LIMIT("bio unserviceable, yet pool is in PM_WRITE mode"); + return true; + + case PM_OUT_OF_DATA_SPACE: + return pool->pf.error_if_no_space; - if (pool->pf.error_if_no_space) + case PM_READ_ONLY: + case PM_FAIL: + return true; + default: + /* Shouldn't get here */ + DMERR_LIMIT("bio unserviceable, yet pool has an unknown mode"); + return true; + } +} + +static void handle_unserviceable_bio(struct pool *pool, struct bio *bio) +{ + if (should_error_unserviceable_bio(pool)) bio_io_error(bio); else retry_on_resume(bio); @@ -1007,11 +1045,20 @@ static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *c struct bio *bio; struct bio_list bios; + if (should_error_unserviceable_bio(pool)) { + cell_error(pool, cell); + return; + } + bio_list_init(&bios); cell_release(pool, cell, &bios); - while ((bio = bio_list_pop(&bios))) - handle_unserviceable_bio(pool, bio); + if (should_error_unserviceable_bio(pool)) + while ((bio = bio_list_pop(&bios))) + bio_io_error(bio); + else + while ((bio = bio_list_pop(&bios))) + retry_on_resume(bio); } static void process_discard(struct thin_c *tc, struct bio *bio) @@ -1296,6 +1343,11 @@ static void process_bio_read_only(struct thin_c *tc, struct bio *bio) } } +static void process_bio_success(struct thin_c *tc, struct bio *bio) +{ + bio_endio(bio, 0); +} + static void process_bio_fail(struct thin_c *tc, struct bio *bio) { bio_io_error(bio); @@ -1328,6 +1380,11 @@ static void process_deferred_bios(struct pool *pool) struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook)); struct thin_c *tc = h->tc; + if (tc->requeue_mode) { + bio_endio(bio, DM_ENDIO_REQUEUE); + continue; + } + /* * If we've got no free new_mapping structs, and processing * this bio might require one, we pause until there are some @@ -1394,51 +1451,134 @@ static void do_waker(struct work_struct *ws) /*----------------------------------------------------------------*/ +struct noflush_work { + struct work_struct worker; + struct thin_c *tc; + + atomic_t complete; + wait_queue_head_t wait; +}; + +static void complete_noflush_work(struct noflush_work *w) +{ + atomic_set(&w->complete, 1); + wake_up(&w->wait); +} + +static void do_noflush_start(struct work_struct *ws) +{ + struct noflush_work *w = container_of(ws, struct noflush_work, worker); + w->tc->requeue_mode = true; + requeue_io(w->tc); + complete_noflush_work(w); +} + +static void do_noflush_stop(struct work_struct *ws) +{ + struct noflush_work *w = container_of(ws, struct noflush_work, worker); + w->tc->requeue_mode = false; + complete_noflush_work(w); +} + +static void noflush_work(struct thin_c *tc, void (*fn)(struct work_struct *)) +{ + struct noflush_work w; + + INIT_WORK(&w.worker, fn); + w.tc = tc; + atomic_set(&w.complete, 0); + init_waitqueue_head(&w.wait); + + queue_work(tc->pool->wq, &w.worker); + + wait_event(w.wait, atomic_read(&w.complete)); +} + +/*----------------------------------------------------------------*/ + static enum pool_mode get_pool_mode(struct pool *pool) { return pool->pf.mode; } +static void notify_of_pool_mode_change(struct pool *pool, const char *new_mode) +{ + dm_table_event(pool->ti->table); + DMINFO("%s: switching pool to %s mode", + dm_device_name(pool->pool_md), new_mode); +} + static void set_pool_mode(struct pool *pool, enum pool_mode new_mode) { - int r; - enum pool_mode old_mode = pool->pf.mode; + struct pool_c *pt = pool->ti->private; + bool needs_check = dm_pool_metadata_needs_check(pool->pmd); + enum pool_mode old_mode = get_pool_mode(pool); + + /* + * Never allow the pool to transition to PM_WRITE mode if user + * intervention is required to verify metadata and data consistency. + */ + if (new_mode == PM_WRITE && needs_check) { + DMERR("%s: unable to switch pool to write mode until repaired.", + dm_device_name(pool->pool_md)); + if (old_mode != new_mode) + new_mode = old_mode; + else + new_mode = PM_READ_ONLY; + } + /* + * If we were in PM_FAIL mode, rollback of metadata failed. We're + * not going to recover without a thin_repair. So we never let the + * pool move out of the old mode. + */ + if (old_mode == PM_FAIL) + new_mode = old_mode; switch (new_mode) { case PM_FAIL: if (old_mode != new_mode) - DMERR("%s: switching pool to failure mode", - dm_device_name(pool->pool_md)); + notify_of_pool_mode_change(pool, "failure"); dm_pool_metadata_read_only(pool->pmd); pool->process_bio = process_bio_fail; pool->process_discard = process_bio_fail; pool->process_prepared_mapping = process_prepared_mapping_fail; pool->process_prepared_discard = process_prepared_discard_fail; + + error_retry_list(pool); break; case PM_READ_ONLY: if (old_mode != new_mode) - DMERR("%s: switching pool to read-only mode", - dm_device_name(pool->pool_md)); - r = dm_pool_abort_metadata(pool->pmd); - if (r) { - DMERR("%s: aborting transaction failed", - dm_device_name(pool->pool_md)); - new_mode = PM_FAIL; - set_pool_mode(pool, new_mode); - } else { - dm_pool_metadata_read_only(pool->pmd); - pool->process_bio = process_bio_read_only; - pool->process_discard = process_discard; - pool->process_prepared_mapping = process_prepared_mapping_fail; - pool->process_prepared_discard = process_prepared_discard_passdown; - } + notify_of_pool_mode_change(pool, "read-only"); + dm_pool_metadata_read_only(pool->pmd); + pool->process_bio = process_bio_read_only; + pool->process_discard = process_bio_success; + pool->process_prepared_mapping = process_prepared_mapping_fail; + pool->process_prepared_discard = process_prepared_discard_passdown; + + error_retry_list(pool); + break; + + case PM_OUT_OF_DATA_SPACE: + /* + * Ideally we'd never hit this state; the low water mark + * would trigger userland to extend the pool before we + * completely run out of data space. However, many small + * IOs to unprovisioned space can consume data space at an + * alarming rate. Adjust your low water mark if you're + * frequently seeing this mode. + */ + if (old_mode != new_mode) + notify_of_pool_mode_change(pool, "out-of-data-space"); + pool->process_bio = process_bio_read_only; + pool->process_discard = process_discard; + pool->process_prepared_mapping = process_prepared_mapping; + pool->process_prepared_discard = process_prepared_discard_passdown; break; case PM_WRITE: if (old_mode != new_mode) - DMINFO("%s: switching pool to write mode", - dm_device_name(pool->pool_md)); + notify_of_pool_mode_change(pool, "write"); dm_pool_metadata_read_write(pool->pmd); pool->process_bio = process_bio; pool->process_discard = process_discard; @@ -1448,32 +1588,35 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode) } pool->pf.mode = new_mode; + /* + * The pool mode may have changed, sync it so bind_control_target() + * doesn't cause an unexpected mode transition on resume. + */ + pt->adjusted_pf.mode = new_mode; } -/* - * Rather than calling set_pool_mode directly, use these which describe the - * reason for mode degradation. - */ -static void out_of_data_space(struct pool *pool) +static void abort_transaction(struct pool *pool) { - DMERR_LIMIT("%s: no free data space available.", - dm_device_name(pool->pool_md)); - set_pool_mode(pool, PM_READ_ONLY); + const char *dev_name = dm_device_name(pool->pool_md); + + DMERR_LIMIT("%s: aborting current metadata transaction", dev_name); + if (dm_pool_abort_metadata(pool->pmd)) { + DMERR("%s: failed to abort metadata transaction", dev_name); + set_pool_mode(pool, PM_FAIL); + } + + if (dm_pool_metadata_set_needs_check(pool->pmd)) { + DMERR("%s: failed to set 'needs_check' flag in metadata", dev_name); + set_pool_mode(pool, PM_FAIL); + } } static void metadata_operation_failed(struct pool *pool, const char *op, int r) { - dm_block_t free_blocks; - DMERR_LIMIT("%s: metadata operation '%s' failed: error = %d", dm_device_name(pool->pool_md), op, r); - if (r == -ENOSPC && - !dm_pool_get_free_metadata_block_count(pool->pmd, &free_blocks) && - !free_blocks) - DMERR_LIMIT("%s: no free metadata space available.", - dm_device_name(pool->pool_md)); - + abort_transaction(pool); set_pool_mode(pool, PM_READ_ONLY); } @@ -1524,6 +1667,11 @@ static int thin_bio_map(struct dm_target *ti, struct bio *bio) thin_hook_bio(tc, bio); + if (tc->requeue_mode) { + bio_endio(bio, DM_ENDIO_REQUEUE); + return DM_MAPIO_SUBMITTED; + } + if (get_pool_mode(tc->pool) == PM_FAIL) { bio_io_error(bio); return DM_MAPIO_SUBMITTED; @@ -1687,7 +1835,7 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti) /* * We want to make sure that a pool in PM_FAIL mode is never upgraded. */ - enum pool_mode old_mode = pool->pf.mode; + enum pool_mode old_mode = get_pool_mode(pool); enum pool_mode new_mode = pt->adjusted_pf.mode; /* @@ -1701,16 +1849,6 @@ static int bind_control_target(struct pool *pool, struct dm_target *ti) pool->pf = pt->adjusted_pf; pool->low_water_blocks = pt->low_water_blocks; - /* - * If we were in PM_FAIL mode, rollback of metadata failed. We're - * not going to recover without a thin_repair. So we never let the - * pool move out of the old mode. On the other hand a PM_READ_ONLY - * may have been due to a lack of metadata or data space, and may - * now work (ie. if the underlying devices have been resized). - */ - if (old_mode == PM_FAIL) - new_mode = old_mode; - set_pool_mode(pool, new_mode); return 0; @@ -2253,6 +2391,12 @@ static int maybe_resize_data_dev(struct dm_target *ti, bool *need_commit) return -EINVAL; } else if (data_size > sb_data_size) { + if (dm_pool_metadata_needs_check(pool->pmd)) { + DMERR("%s: unable to grow the data device until repaired.", + dm_device_name(pool->pool_md)); + return 0; + } + if (sb_data_size) DMINFO("%s: growing the data device from %llu to %llu blocks", dm_device_name(pool->pool_md), @@ -2294,6 +2438,12 @@ static int maybe_resize_metadata_dev(struct dm_target *ti, bool *need_commit) return -EINVAL; } else if (metadata_dev_size > sb_metadata_dev_size) { + if (dm_pool_metadata_needs_check(pool->pmd)) { + DMERR("%s: unable to grow the metadata device until repaired.", + dm_device_name(pool->pool_md)); + return 0; + } + warn_if_metadata_device_too_big(pool->md_dev); DMINFO("%s: growing the metadata device from %llu to %llu blocks", dm_device_name(pool->pool_md), @@ -2681,7 +2831,9 @@ static void pool_status(struct dm_target *ti, status_type_t type, else DMEMIT("- "); - if (pool->pf.mode == PM_READ_ONLY) + if (pool->pf.mode == PM_OUT_OF_DATA_SPACE) + DMEMIT("out_of_data_space "); + else if (pool->pf.mode == PM_READ_ONLY) DMEMIT("ro "); else DMEMIT("rw "); @@ -2795,7 +2947,7 @@ static struct target_type pool_target = { .name = "thin-pool", .features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE | DM_TARGET_IMMUTABLE, - .version = {1, 10, 0}, + .version = {1, 11, 0}, .module = THIS_MODULE, .ctr = pool_ctr, .dtr = pool_dtr, @@ -2997,10 +3149,23 @@ static int thin_endio(struct dm_target *ti, struct bio *bio, int err) return 0; } -static void thin_postsuspend(struct dm_target *ti) +static void thin_presuspend(struct dm_target *ti) { + struct thin_c *tc = ti->private; + if (dm_noflush_suspending(ti)) - requeue_io((struct thin_c *)ti->private); + noflush_work(tc, do_noflush_start); +} + +static void thin_postsuspend(struct dm_target *ti) +{ + struct thin_c *tc = ti->private; + + /* + * The dm_noflush_suspending flag has been cleared by now, so + * unfortunately we must always run this. + */ + noflush_work(tc, do_noflush_stop); } /* @@ -3085,12 +3250,13 @@ static int thin_iterate_devices(struct dm_target *ti, static struct target_type thin_target = { .name = "thin", - .version = {1, 10, 0}, + .version = {1, 11, 0}, .module = THIS_MODULE, .ctr = thin_ctr, .dtr = thin_dtr, .map = thin_map, .end_io = thin_endio, + .presuspend = thin_presuspend, .postsuspend = thin_postsuspend, .status = thin_status, .iterate_devices = thin_iterate_devices, diff --git a/drivers/md/persistent-data/Kconfig b/drivers/md/persistent-data/Kconfig index 19b2687..0c2dec7 100644 --- a/drivers/md/persistent-data/Kconfig +++ b/drivers/md/persistent-data/Kconfig @@ -6,3 +6,13 @@ config DM_PERSISTENT_DATA ---help--- Library providing immutable on-disk data structure support for device-mapper targets such as the thin provisioning target. + +config DM_DEBUG_BLOCK_STACK_TRACING + boolean "Keep stack trace of persistent data block lock holders" + depends on STACKTRACE_SUPPORT && DM_PERSISTENT_DATA + select STACKTRACE + ---help--- + Enable this for messages that may help debug problems with the + block manager locking used by thin provisioning and caching. + + If unsure, say N. diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c index e9bdd46..786b689 100644 --- a/drivers/md/persistent-data/dm-space-map-metadata.c +++ b/drivers/md/persistent-data/dm-space-map-metadata.c @@ -91,6 +91,69 @@ struct block_op { dm_block_t block; }; +struct bop_ring_buffer { + unsigned begin; + unsigned end; + struct block_op bops[MAX_RECURSIVE_ALLOCATIONS + 1]; +}; + +static void brb_init(struct bop_ring_buffer *brb) +{ + brb->begin = 0; + brb->end = 0; +} + +static bool brb_empty(struct bop_ring_buffer *brb) +{ + return brb->begin == brb->end; +} + +static unsigned brb_next(struct bop_ring_buffer *brb, unsigned old) +{ + unsigned r = old + 1; + return (r >= (sizeof(brb->bops) / sizeof(*brb->bops))) ? 0 : r; +} + +static int brb_push(struct bop_ring_buffer *brb, + enum block_op_type type, dm_block_t b) +{ + struct block_op *bop; + unsigned next = brb_next(brb, brb->end); + + /* + * We don't allow the last bop to be filled, this way we can + * differentiate between full and empty. + */ + if (next == brb->begin) + return -ENOMEM; + + bop = brb->bops + brb->end; + bop->type = type; + bop->block = b; + + brb->end = next; + + return 0; +} + +static int brb_pop(struct bop_ring_buffer *brb, struct block_op *result) +{ + struct block_op *bop; + + if (brb_empty(brb)) + return -ENODATA; + + bop = brb->bops + brb->begin; + result->type = bop->type; + result->block = bop->block; + + brb->begin = brb_next(brb, brb->begin); + + return 0; +} + +/*----------------------------------------------------------------*/ + struct sm_metadata { struct dm_space_map sm; @@ -101,25 +164,20 @@ struct sm_metadata { unsigned recursion_count; unsigned allocated_this_transaction; - unsigned nr_uncommitted; - struct block_op uncommitted[MAX_RECURSIVE_ALLOCATIONS]; + struct bop_ring_buffer uncommitted; struct threshold threshold; }; static int add_bop(struct sm_metadata *smm, enum block_op_type type, dm_block_t b) { - struct block_op *op; + int r = brb_push(&smm->uncommitted, type, b); - if (smm->nr_uncommitted == MAX_RECURSIVE_ALLOCATIONS) { + if (r) { DMERR("too many recursive allocations"); return -ENOMEM; } - op = smm->uncommitted + smm->nr_uncommitted++; - op->type = type; - op->block = b; - return 0; } @@ -158,11 +216,17 @@ static int out(struct sm_metadata *smm) return -ENOMEM; } - if (smm->recursion_count == 1 && smm->nr_uncommitted) { - while (smm->nr_uncommitted && !r) { - smm->nr_uncommitted--; - r = commit_bop(smm, smm->uncommitted + - smm->nr_uncommitted); + if (smm->recursion_count == 1) { + while (!brb_empty(&smm->uncommitted)) { + struct block_op bop; + + r = brb_pop(&smm->uncommitted, &bop); + if (r) { + DMERR("bug in bop ring buffer"); + break; + } + + r = commit_bop(smm, &bop); if (r) break; } @@ -217,7 +281,8 @@ static int sm_metadata_get_nr_free(struct dm_space_map *sm, dm_block_t *count) static int sm_metadata_get_count(struct dm_space_map *sm, dm_block_t b, uint32_t *result) { - int r, i; + int r; + unsigned i; struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm); unsigned adjustment = 0; @@ -225,8 +290,10 @@ static int sm_metadata_get_count(struct dm_space_map *sm, dm_block_t b, * We may have some uncommitted adjustments to add. This list * should always be really short. */ - for (i = 0; i < smm->nr_uncommitted; i++) { - struct block_op *op = smm->uncommitted + i; + for (i = smm->uncommitted.begin; + i != smm->uncommitted.end; + i = brb_next(&smm->uncommitted, i)) { + struct block_op *op = smm->uncommitted.bops + i; if (op->block != b) continue; @@ -254,7 +321,8 @@ static int sm_metadata_get_count(struct dm_space_map *sm, dm_block_t b, static int sm_metadata_count_is_more_than_one(struct dm_space_map *sm, dm_block_t b, int *result) { - int r, i, adjustment = 0; + int r, adjustment = 0; + unsigned i; struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm); uint32_t rc; @@ -262,8 +330,11 @@ static int sm_metadata_count_is_more_than_one(struct dm_space_map *sm, * We may have some uncommitted adjustments to add. This list * should always be really short. */ - for (i = 0; i < smm->nr_uncommitted; i++) { - struct block_op *op = smm->uncommitted + i; + for (i = smm->uncommitted.begin; + i != smm->uncommitted.end; + i = brb_next(&smm->uncommitted, i)) { + + struct block_op *op = smm->uncommitted.bops + i; if (op->block != b) continue; @@ -671,7 +742,7 @@ int dm_sm_metadata_create(struct dm_space_map *sm, smm->begin = superblock + 1; smm->recursion_count = 0; smm->allocated_this_transaction = 0; - smm->nr_uncommitted = 0; + brb_init(&smm->uncommitted); threshold_init(&smm->threshold); memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm)); @@ -715,7 +786,7 @@ int dm_sm_metadata_open(struct dm_space_map *sm, smm->begin = 0; smm->recursion_count = 0; smm->allocated_this_transaction = 0; - smm->nr_uncommitted = 0; + brb_init(&smm->uncommitted); threshold_init(&smm->threshold); memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll)); |
