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[68.160.141.91]) by smtp.gmail.com with ESMTPSA id o21-20020ac872d5000000b004120400921csm636716qtp.94.2023.09.14.12.17.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Sep 2023 12:17:41 -0700 (PDT) From: Mike Snitzer To: dm-devel@redhat.com Date: Thu, 14 Sep 2023 15:16:29 -0400 Message-Id: <20230914191635.39805-34-snitzer@kernel.org> In-Reply-To: <20230914191635.39805-1-snitzer@kernel.org> References: <20230914191635.39805-1-snitzer@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.2 Subject: [dm-devel] [PATCH v3 33/39] dm vdo: add the vdo structure itself X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Matthew Sakai Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org From: Matthew Sakai Add the data and methods that manage the dm-vdo target itself. This includes the overall state of the target and its threads, the state of the logical volumes, startup, shutdown, and statistics. Co-developed-by: J. corwin Coburn Signed-off-by: J. corwin Coburn Co-developed-by: Michael Sclafani Signed-off-by: Michael Sclafani Co-developed-by: Sweet Tea Dorminy Signed-off-by: Sweet Tea Dorminy Signed-off-by: Matthew Sakai Signed-off-by: Mike Snitzer --- drivers/md/dm-vdo/vdo.c | 1845 +++++++++++++++++++++++++++++++++++++++ drivers/md/dm-vdo/vdo.h | 381 ++++++++ 2 files changed, 2226 insertions(+) create mode 100644 drivers/md/dm-vdo/vdo.c create mode 100644 drivers/md/dm-vdo/vdo.h diff --git a/drivers/md/dm-vdo/vdo.c b/drivers/md/dm-vdo/vdo.c new file mode 100644 index 000000000000..72cbe6921893 --- /dev/null +++ b/drivers/md/dm-vdo/vdo.c @@ -0,0 +1,1845 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2023 Red Hat + */ + +/* + * This file contains the main entry points for normal operations on a vdo as well as functions for + * constructing and destroying vdo instances (in memory). + */ + +/** + * DOC: + * + * A read_only_notifier has a single completion which is used to perform read-only notifications, + * however, vdo_enter_read_only_mode() may be called from any thread. A pair of fields, protected + * by a spinlock, are used to control the read-only mode entry process. The first field holds the + * read-only error. The second is the state field, which may hold any of the four special values + * enumerated here. + * + * When vdo_enter_read_only_mode() is called from some vdo thread, if the read_only_error field + * already contains an error (i.e. its value is not VDO_SUCCESS), then some other error has already + * initiated the read-only process, and nothing more is done. Otherwise, the new error is stored in + * the read_only_error field, and the state field is consulted. If the state is MAY_NOTIFY, it is + * set to NOTIFYING, and the notification process begins. If the state is MAY_NOT_NOTIFY, then + * notifications are currently disallowed, generally due to the vdo being suspended. In this case, + * the nothing more will be done until the vdo is resumed, at which point the notification will be + * performed. In any other case, the vdo is already read-only, and there is nothing more to do. + */ + +#include "vdo.h" + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "logger.h" +#include "memory-alloc.h" +#include "permassert.h" +#include "string-utils.h" + +#include "block-map.h" +#include "completion.h" +#include "data-vio.h" +#include "dedupe.h" +#include "encodings.h" +#include "io-submitter.h" +#include "logical-zone.h" +#include "packer.h" +#include "physical-zone.h" +#include "pool-sysfs.h" +#include "recovery-journal.h" +#include "slab-depot.h" +#include "statistics.h" +#include "status-codes.h" +#include "vio.h" +#include "work-queue.h" + + +enum { PARANOID_THREAD_CONSISTENCY_CHECKS = 0 }; + +struct sync_completion { + struct vdo_completion vdo_completion; + struct completion completion; +}; + +/* + * We don't expect this set to ever get really large, so a linked list is adequate. We can use a + * pointer_map if we need to later. + */ +struct device_registry { + struct list_head links; + /* TODO: Convert to rcu per kernel recommendation. */ + rwlock_t lock; +}; + +static struct device_registry registry; + +/** + * vdo_initialize_device_registry_once() - Initialize the necessary structures for the device + * registry. + */ +void vdo_initialize_device_registry_once(void) +{ + INIT_LIST_HEAD(®istry.links); + rwlock_init(®istry.lock); +} + +/** vdo_is_equal() - Implements vdo_filter_t. */ +static bool vdo_is_equal(struct vdo *vdo, const void *context) +{ + return ((void *) vdo == context); +} + +/** + * filter_vdos_locked() - Find a vdo in the registry if it exists there. + * @filter: The filter function to apply to devices. + * @context: A bit of context to provide the filter. + * + * Context: Must be called holding the lock. + * + * Return: the vdo object found, if any. + */ +static struct vdo * __must_check filter_vdos_locked(vdo_filter_t *filter, const void *context) +{ + struct vdo *vdo; + + list_for_each_entry(vdo, ®istry.links, registration) + if (filter(vdo, context)) + return vdo; + + return NULL; +} + +/** + * vdo_find_matching() - Find and return the first (if any) vdo matching a given filter function. + * @filter: The filter function to apply to vdos. + * @context: A bit of context to provide the filter. + */ +struct vdo *vdo_find_matching(vdo_filter_t *filter, const void *context) +{ + struct vdo *vdo; + + read_lock(®istry.lock); + vdo = filter_vdos_locked(filter, context); + read_unlock(®istry.lock); + return vdo; +} + +static void start_vdo_request_queue(void *ptr) +{ + struct vdo_thread *thread = vdo_get_work_queue_owner(vdo_get_current_work_queue()); + + uds_register_allocating_thread(&thread->allocating_thread, + &thread->vdo->allocations_allowed); +} + +static void finish_vdo_request_queue(void *ptr) +{ + uds_unregister_allocating_thread(); +} + +#ifdef MODULE +#define MODULE_NAME THIS_MODULE->name +#else +#define MODULE_NAME "dm-vdo" +#endif /* MODULE */ + +static const struct vdo_work_queue_type default_queue_type = { + .start = start_vdo_request_queue, + .finish = finish_vdo_request_queue, + .max_priority = VDO_DEFAULT_Q_MAX_PRIORITY, + .default_priority = VDO_DEFAULT_Q_COMPLETION_PRIORITY, +}; + +static const struct vdo_work_queue_type bio_ack_q_type = { + .start = NULL, + .finish = NULL, + .max_priority = BIO_ACK_Q_MAX_PRIORITY, + .default_priority = BIO_ACK_Q_ACK_PRIORITY, +}; + +static const struct vdo_work_queue_type cpu_q_type = { + .start = NULL, + .finish = NULL, + .max_priority = CPU_Q_MAX_PRIORITY, + .default_priority = CPU_Q_MAX_PRIORITY, +}; + +static void uninitialize_thread_config(struct thread_config *config) +{ + UDS_FREE(UDS_FORGET(config->logical_threads)); + UDS_FREE(UDS_FORGET(config->physical_threads)); + UDS_FREE(UDS_FORGET(config->hash_zone_threads)); + UDS_FREE(UDS_FORGET(config->bio_threads)); + memset(config, 0, sizeof(struct thread_config)); +} + +static void +assign_thread_ids(struct thread_config *config, thread_id_t thread_ids[], zone_count_t count) +{ + zone_count_t zone; + + for (zone = 0; zone < count; zone++) + thread_ids[zone] = config->thread_count++; +} + +/** + * initialize_thread_config() - Initialize the thread mapping + * + * If the logical, physical, and hash zone counts are all 0, a single thread will be shared by all + * three plus the packer and recovery journal. Otherwise, there must be at least one of each type, + * and each will have its own thread, as will the packer and recovery journal. + * + * Return: VDO_SUCCESS or an error. + */ +static int __must_check +initialize_thread_config(struct thread_count_config counts, struct thread_config *config) +{ + int result; + bool single = ((counts.logical_zones + counts.physical_zones + counts.hash_zones) == 0); + + config->bio_thread_count = counts.bio_threads; + if (single) { + config->logical_zone_count = 1; + config->physical_zone_count = 1; + config->hash_zone_count = 1; + } else { + config->logical_zone_count = counts.logical_zones; + config->physical_zone_count = counts.physical_zones; + config->hash_zone_count = counts.hash_zones; + } + + result = UDS_ALLOCATE(config->logical_zone_count, + thread_id_t, + "logical thread array", + &config->logical_threads); + if (result != VDO_SUCCESS) { + uninitialize_thread_config(config); + return result; + } + + result = UDS_ALLOCATE(config->physical_zone_count, + thread_id_t, + "physical thread array", + &config->physical_threads); + if (result != VDO_SUCCESS) { + uninitialize_thread_config(config); + return result; + } + + result = UDS_ALLOCATE(config->hash_zone_count, + thread_id_t, + "hash thread array", + &config->hash_zone_threads); + if (result != VDO_SUCCESS) { + uninitialize_thread_config(config); + return result; + } + + result = UDS_ALLOCATE(config->bio_thread_count, + thread_id_t, + "bio thread array", + &config->bio_threads); + if (result != VDO_SUCCESS) { + uninitialize_thread_config(config); + return result; + } + + if (single) { + config->logical_threads[0] = config->thread_count; + config->physical_threads[0] = config->thread_count; + config->hash_zone_threads[0] = config->thread_count++; + } else { + config->admin_thread = config->thread_count; + config->journal_thread = config->thread_count++; + config->packer_thread = config->thread_count++; + assign_thread_ids(config, config->logical_threads, counts.logical_zones); + assign_thread_ids(config, config->physical_threads, counts.physical_zones); + assign_thread_ids(config, config->hash_zone_threads, counts.hash_zones); + } + + config->dedupe_thread = config->thread_count++; + config->bio_ack_thread = + ((counts.bio_ack_threads > 0) ? config->thread_count++ : VDO_INVALID_THREAD_ID); + config->cpu_thread = config->thread_count++; + assign_thread_ids(config, config->bio_threads, counts.bio_threads); + return VDO_SUCCESS; +} + +/** + * vdo_read_geometry_block() - Synchronously read the geometry block from a vdo's underlying block + * device. + * @vdo: The vdo whose geometry is to be read. + * + * Return: VDO_SUCCESS or an error code. + */ +static int __must_check read_geometry_block(struct vdo *vdo) +{ + struct vio *vio; + char *block; + int result; + + result = UDS_ALLOCATE(VDO_BLOCK_SIZE, u8, __func__, &block); + if (result != VDO_SUCCESS) + return result; + + result = create_metadata_vio(vdo, VIO_TYPE_GEOMETRY, VIO_PRIORITY_HIGH, NULL, block, &vio); + if (result != VDO_SUCCESS) { + UDS_FREE(block); + return result; + } + + /* + * This is only safe because, having not already loaded the geometry, the vdo's geometry's + * bio_offset field is 0, so the fact that vio_reset_bio() will subtract that offset from + * the supplied pbn is not a problem. + */ + result = vio_reset_bio(vio, block, NULL, REQ_OP_READ, VDO_GEOMETRY_BLOCK_LOCATION); + if (result != VDO_SUCCESS) { + free_vio(UDS_FORGET(vio)); + UDS_FREE(block); + return result; + } + + bio_set_dev(vio->bio, vdo_get_backing_device(vdo)); + submit_bio_wait(vio->bio); + result = blk_status_to_errno(vio->bio->bi_status); + free_vio(UDS_FORGET(vio)); + if (result != 0) { + uds_log_error_strerror(result, "synchronous read failed"); + UDS_FREE(block); + return -EIO; + } + + result = vdo_parse_geometry_block((u8 *) block, &vdo->geometry); + UDS_FREE(block); + return result; +} + +static bool get_zone_thread_name(const thread_id_t thread_ids[], + zone_count_t count, + thread_id_t id, + const char *prefix, + char *buffer, + size_t buffer_length) +{ + if (id >= thread_ids[0]) { + thread_id_t index = id - thread_ids[0]; + + if (index < count) { + snprintf(buffer, buffer_length, "%s%d", prefix, index); + return true; + } + } + return false; +} + +/** + * get_thread_name() - Format the name of the worker thread desired to support a given work queue. + * @thread_config: The thread configuration. + * @thread_id: The thread id. + * @buffer: Where to put the formatted name. + * @buffer_length: Size of the output buffer. + * + * The physical layer may add a prefix identifying the product; the output from this function + * should just identify the thread. + */ +static void +get_thread_name(const struct thread_config *thread_config, + thread_id_t thread_id, + char *buffer, + size_t buffer_length) +{ + if (thread_id == thread_config->journal_thread) { + if (thread_config->packer_thread == thread_id) { + /* + * This is the "single thread" config where one thread is used for the + * journal, packer, logical, physical, and hash zones. In that case, it is + * known as the "request queue." + */ + snprintf(buffer, buffer_length, "reqQ"); + return; + } + + snprintf(buffer, buffer_length, "journalQ"); + return; + } else if (thread_id == thread_config->admin_thread) { + /* Theoretically this could be different from the journal thread. */ + snprintf(buffer, buffer_length, "adminQ"); + return; + } else if (thread_id == thread_config->packer_thread) { + snprintf(buffer, buffer_length, "packerQ"); + return; + } else if (thread_id == thread_config->dedupe_thread) { + snprintf(buffer, buffer_length, "dedupeQ"); + return; + } else if (thread_id == thread_config->bio_ack_thread) { + snprintf(buffer, buffer_length, "ackQ"); + return; + } else if (thread_id == thread_config->cpu_thread) { + snprintf(buffer, buffer_length, "cpuQ"); + return; + } + + if (get_zone_thread_name(thread_config->logical_threads, + thread_config->logical_zone_count, + thread_id, + "logQ", + buffer, + buffer_length)) + return; + + if (get_zone_thread_name(thread_config->physical_threads, + thread_config->physical_zone_count, + thread_id, + "physQ", + buffer, + buffer_length)) + return; + + if (get_zone_thread_name(thread_config->hash_zone_threads, + thread_config->hash_zone_count, + thread_id, + "hashQ", + buffer, + buffer_length)) + return; + + if (get_zone_thread_name(thread_config->bio_threads, + thread_config->bio_thread_count, + thread_id, + "bioQ", + buffer, + buffer_length)) + return; + + /* Some sort of misconfiguration? */ + snprintf(buffer, buffer_length, "reqQ%d", thread_id); +} + +/** + * vdo_make_thread() - Construct a single vdo work_queue and its associated thread (or threads for + * round-robin queues). + * @vdo: The vdo which owns the thread. + * @thread_id: The id of the thread to create (as determined by the thread_config). + * @type: The description of the work queue for this thread. + * @queue_count: The number of actual threads/queues contained in the "thread". + * @contexts: An array of queue_count contexts, one for each individual queue; may be NULL. + * + * Each "thread" constructed by this method is represented by a unique thread id in the thread + * config, and completions can be enqueued to the queue and run on the threads comprising this + * entity. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_make_thread(struct vdo *vdo, + thread_id_t thread_id, + const struct vdo_work_queue_type *type, + unsigned int queue_count, + void *contexts[]) +{ + struct vdo_thread *thread = &vdo->threads[thread_id]; + char queue_name[MAX_VDO_WORK_QUEUE_NAME_LEN]; + + if (type == NULL) + type = &default_queue_type; + + if (thread->queue != NULL) + return ASSERT(vdo_work_queue_type_is(thread->queue, type), + "already constructed vdo thread %u is of the correct type", + thread_id); + + thread->vdo = vdo; + thread->thread_id = thread_id; + get_thread_name(&vdo->thread_config, thread_id, queue_name, sizeof(queue_name)); + return vdo_make_work_queue(vdo->thread_name_prefix, + queue_name, + thread, + type, + queue_count, + contexts, + &thread->queue); +} + +/** + * register_vdo() - Register a VDO; it must not already be registered. + * @vdo: The vdo to register. + * + * Return: VDO_SUCCESS or an error. + */ +static int register_vdo(struct vdo *vdo) +{ + int result; + + write_lock(®istry.lock); + result = ASSERT(filter_vdos_locked(vdo_is_equal, vdo) == NULL, + "VDO not already registered"); + if (result == VDO_SUCCESS) { + INIT_LIST_HEAD(&vdo->registration); + list_add_tail(&vdo->registration, ®istry.links); + } + write_unlock(®istry.lock); + + return result; +} + +/** + * initialize_vdo() - Do the portion of initializing a vdo which will clean up after itself on + * error. + * @vdo: The vdo being initialized + * @config: The configuration of the vdo + * @instance: The instance number of the vdo + * @reason: The buffer to hold the failure reason on error + */ +static int +initialize_vdo(struct vdo *vdo, struct device_config *config, unsigned int instance, char **reason) +{ + int result; + zone_count_t i; + + vdo->device_config = config; + vdo->starting_sector_offset = config->owning_target->begin; + vdo->instance = instance; + vdo->allocations_allowed = true; + vdo_set_admin_state_code(&vdo->admin.state, VDO_ADMIN_STATE_NEW); + INIT_LIST_HEAD(&vdo->device_config_list); + vdo_initialize_completion(&vdo->admin.completion, vdo, VDO_ADMIN_COMPLETION); + init_completion(&vdo->admin.callback_sync); + mutex_init(&vdo->stats_mutex); + result = read_geometry_block(vdo); + if (result != VDO_SUCCESS) { + *reason = "Could not load geometry block"; + return result; + } + + result = initialize_thread_config(config->thread_counts, &vdo->thread_config); + if (result != VDO_SUCCESS) { + *reason = "Cannot create thread configuration"; + return result; + } + + uds_log_info("zones: %d logical, %d physical, %d hash; total threads: %d", + config->thread_counts.logical_zones, + config->thread_counts.physical_zones, + config->thread_counts.hash_zones, + vdo->thread_config.thread_count); + + /* Compression context storage */ + result = UDS_ALLOCATE(config->thread_counts.cpu_threads, + char *, + "LZ4 context", + &vdo->compression_context); + if (result != VDO_SUCCESS) { + *reason = "cannot allocate LZ4 context"; + return result; + } + + for (i = 0; i < config->thread_counts.cpu_threads; i++) { + result = UDS_ALLOCATE(LZ4_MEM_COMPRESS, + char, + "LZ4 context", + &vdo->compression_context[i]); + if (result != VDO_SUCCESS) { + *reason = "cannot allocate LZ4 context"; + return result; + } + } + + result = register_vdo(vdo); + if (result != VDO_SUCCESS) { + *reason = "Cannot add VDO to device registry"; + return result; + } + + vdo_set_admin_state_code(&vdo->admin.state, VDO_ADMIN_STATE_INITIALIZED); + return result; +} + +/** + * vdo_make() - Allocate and initialize a vdo. + * @instance: Device instantiation counter. + * @config: The device configuration. + * @reason: The reason for any failure during this call. + * @vdo_ptr: A pointer to hold the created vdo. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_make(unsigned int instance, + struct device_config *config, + char **reason, + struct vdo **vdo_ptr) +{ + int result; + struct vdo *vdo; + + /* VDO-3769 - Set a generic reason so we don't ever return garbage. */ + *reason = "Unspecified error"; + + result = UDS_ALLOCATE(1, struct vdo, __func__, &vdo); + if (result != UDS_SUCCESS) { + *reason = "Cannot allocate VDO"; + return result; + } + + result = initialize_vdo(vdo, config, instance, reason); + if (result != VDO_SUCCESS) { + vdo_destroy(vdo); + return result; + } + + /* From here on, the caller will clean up if there is an error. */ + *vdo_ptr = vdo; + + snprintf(vdo->thread_name_prefix, + sizeof(vdo->thread_name_prefix), + "%s%u", + MODULE_NAME, + instance); + BUG_ON(vdo->thread_name_prefix[0] == '\0'); + result = UDS_ALLOCATE(vdo->thread_config.thread_count, + struct vdo_thread, + __func__, + &vdo->threads); + if (result != VDO_SUCCESS) { + *reason = "Cannot allocate thread structures"; + return result; + } + + result = vdo_make_thread(vdo, + vdo->thread_config.admin_thread, + &default_queue_type, + 1, + NULL); + if (result != VDO_SUCCESS) { + *reason = "Cannot make admin thread"; + return result; + } + + result = vdo_make_flusher(vdo); + if (result != VDO_SUCCESS) { + *reason = "Cannot make flusher zones"; + return result; + } + + result = vdo_make_packer(vdo, DEFAULT_PACKER_BINS, &vdo->packer); + if (result != VDO_SUCCESS) { + *reason = "Cannot make packer zones"; + return result; + } + + BUG_ON(vdo->device_config->logical_block_size <= 0); + BUG_ON(vdo->device_config->owned_device == NULL); + result = make_data_vio_pool(vdo, + MAXIMUM_VDO_USER_VIOS, + MAXIMUM_VDO_USER_VIOS * 3 / 4, + &vdo->data_vio_pool); + if (result != VDO_SUCCESS) { + *reason = "Cannot allocate data_vio pool"; + return result; + } + + result = vdo_make_io_submitter(config->thread_counts.bio_threads, + config->thread_counts.bio_rotation_interval, + get_data_vio_pool_request_limit(vdo->data_vio_pool), + vdo, + &vdo->io_submitter); + if (result != VDO_SUCCESS) { + *reason = "bio submission initialization failed"; + return result; + } + + if (vdo_uses_bio_ack_queue(vdo)) { + result = vdo_make_thread(vdo, + vdo->thread_config.bio_ack_thread, + &bio_ack_q_type, + config->thread_counts.bio_ack_threads, + NULL); + if (result != VDO_SUCCESS) { + *reason = "bio ack queue initialization failed"; + return result; + } + } + + result = vdo_make_thread(vdo, + vdo->thread_config.cpu_thread, + &cpu_q_type, + config->thread_counts.cpu_threads, + (void **) vdo->compression_context); + if (result != VDO_SUCCESS) { + *reason = "CPU queue initialization failed"; + return result; + } + + return VDO_SUCCESS; +} + +static void finish_vdo(struct vdo *vdo) +{ + int i; + + if (vdo->threads == NULL) + return; + + vdo_cleanup_io_submitter(vdo->io_submitter); + vdo_finish_dedupe_index(vdo->hash_zones); + + for (i = 0; i < vdo->thread_config.thread_count; i++) + vdo_finish_work_queue(vdo->threads[i].queue); +} + +/** + * free_listeners() - Free the list of read-only listeners associated with a thread. + * @thread_data: The thread holding the list to free. + */ +static void free_listeners(struct vdo_thread *thread) +{ + struct read_only_listener *listener, *next; + + for (listener = UDS_FORGET(thread->listeners); listener != NULL; listener = next) { + next = UDS_FORGET(listener->next); + UDS_FREE(listener); + } +} + +static void uninitialize_super_block(struct vdo_super_block *super_block) +{ + free_vio_components(&super_block->vio); + UDS_FREE(super_block->buffer); +} + +/** + * unregister_vdo() - Remove a vdo from the device registry. + * @vdo: The vdo to remove. + */ +static void unregister_vdo(struct vdo *vdo) +{ + write_lock(®istry.lock); + if (filter_vdos_locked(vdo_is_equal, vdo) == vdo) + list_del_init(&vdo->registration); + + write_unlock(®istry.lock); +} + +/** + * vdo_destroy() - Destroy a vdo instance. + * @vdo: The vdo to destroy (may be NULL). + */ +void vdo_destroy(struct vdo *vdo) +{ + unsigned int i; + + if (vdo == NULL) + return; + + /* A running VDO should never be destroyed without suspending first. */ + BUG_ON(vdo_get_admin_state(vdo)->normal); + + vdo->allocations_allowed = true; + + /* Stop services that need to gather VDO statistics from the worker threads. */ + if (vdo->sysfs_added) { + init_completion(&vdo->stats_shutdown); + kobject_put(&vdo->stats_directory); + wait_for_completion(&vdo->stats_shutdown); + } + + finish_vdo(vdo); + unregister_vdo(vdo); + free_data_vio_pool(vdo->data_vio_pool); + vdo_free_io_submitter(UDS_FORGET(vdo->io_submitter)); + vdo_free_flusher(UDS_FORGET(vdo->flusher)); + vdo_free_packer(UDS_FORGET(vdo->packer)); + vdo_free_recovery_journal(UDS_FORGET(vdo->recovery_journal)); + vdo_free_slab_depot(UDS_FORGET(vdo->depot)); + vdo_uninitialize_layout(&vdo->layout); + vdo_uninitialize_layout(&vdo->next_layout); + if (vdo->partition_copier) + dm_kcopyd_client_destroy(UDS_FORGET(vdo->partition_copier)); + uninitialize_super_block(&vdo->super_block); + vdo_free_block_map(UDS_FORGET(vdo->block_map)); + vdo_free_hash_zones(UDS_FORGET(vdo->hash_zones)); + vdo_free_physical_zones(UDS_FORGET(vdo->physical_zones)); + vdo_free_logical_zones(UDS_FORGET(vdo->logical_zones)); + + if (vdo->threads != NULL) { + for (i = 0; i < vdo->thread_config.thread_count; i++) { + free_listeners(&vdo->threads[i]); + vdo_free_work_queue(UDS_FORGET(vdo->threads[i].queue)); + } + UDS_FREE(UDS_FORGET(vdo->threads)); + } + + uninitialize_thread_config(&vdo->thread_config); + + if (vdo->compression_context != NULL) { + for (i = 0; i < vdo->device_config->thread_counts.cpu_threads; i++) + UDS_FREE(UDS_FORGET(vdo->compression_context[i])); + + UDS_FREE(UDS_FORGET(vdo->compression_context)); + } + + /* + * The call to kobject_put on the kobj sysfs node will decrement its reference count; when + * the count goes to zero the VDO object will be freed as a side effect. + */ + if (!vdo->sysfs_added) + UDS_FREE(vdo); + else + kobject_put(&vdo->vdo_directory); +} + +static int initialize_super_block(struct vdo *vdo, struct vdo_super_block *super_block) +{ + int result; + + result = UDS_ALLOCATE(VDO_BLOCK_SIZE, + char, + "encoded super block", + (char **) &vdo->super_block.buffer); + if (result != VDO_SUCCESS) + return result; + + return allocate_vio_components(vdo, + VIO_TYPE_SUPER_BLOCK, + VIO_PRIORITY_METADATA, + NULL, + 1, + (char *) super_block->buffer, + &vdo->super_block.vio); +} + +/** + * finish_reading_super_block() - Continue after loading the super block. + * @completion: The super block vio. + * + * This callback is registered in vdo_load_super_block(). + */ +static void finish_reading_super_block(struct vdo_completion *completion) +{ + struct vdo_super_block *super_block = + container_of(as_vio(completion), struct vdo_super_block, vio); + + vdo_continue_completion(UDS_FORGET(completion->parent), + vdo_decode_super_block(super_block->buffer)); +} + +/** + * handle_super_block_read_error() - Handle an error reading the super block. + * @completion: The super block vio. + * + * This error handler is registered in vdo_load_super_block(). + */ +static void handle_super_block_read_error(struct vdo_completion *completion) +{ + vio_record_metadata_io_error(as_vio(completion)); + finish_reading_super_block(completion); +} + +static void read_super_block_endio(struct bio *bio) +{ + struct vio *vio = bio->bi_private; + struct vdo_completion *parent = vio->completion.parent; + + continue_vio_after_io(vio, finish_reading_super_block, parent->callback_thread_id); +} + +/** + * vdo_load_super_block() - Allocate a super block and read its contents from storage. + * @vdo: The vdo containing the super block on disk. + * @parent: The completion to notify after loading the super block. + */ +void vdo_load_super_block(struct vdo *vdo, struct vdo_completion *parent) +{ + int result; + + result = initialize_super_block(vdo, &vdo->super_block); + if (result != VDO_SUCCESS) { + vdo_continue_completion(parent, result); + return; + } + + vdo->super_block.vio.completion.parent = parent; + submit_metadata_vio(&vdo->super_block.vio, + vdo_get_data_region_start(vdo->geometry), + read_super_block_endio, + handle_super_block_read_error, + REQ_OP_READ); +} + +/** + * pool_stats_release() - Signal that sysfs stats have been shut down. + * @directory: The vdo stats directory. + */ +static void pool_stats_release(struct kobject *directory) +{ + struct vdo *vdo = container_of(directory, struct vdo, stats_directory); + + complete(&vdo->stats_shutdown); +} + +ATTRIBUTE_GROUPS(vdo_pool_stats); +static const struct kobj_type stats_directory_type = { + .release = pool_stats_release, + .sysfs_ops = &vdo_pool_stats_sysfs_ops, + .default_groups = vdo_pool_stats_groups, +}; + +/** + * vdo_add_sysfs_stats_dir() - Add the stats directory to the vdo sysfs directory. + * @vdo: The vdo. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_add_sysfs_stats_dir(struct vdo *vdo) +{ + int result; + + kobject_init(&vdo->stats_directory, &stats_directory_type); + result = kobject_add(&vdo->stats_directory, &vdo->vdo_directory, "statistics"); + if (result != 0) + return VDO_CANT_ADD_SYSFS_NODE; + + return VDO_SUCCESS; +} + +/** + * vdo_get_backing_device() - Get the block device object underlying a vdo. + * @vdo: The vdo. + * + * Return: The vdo's current block device. + */ +struct block_device *vdo_get_backing_device(const struct vdo *vdo) +{ + return vdo->device_config->owned_device->bdev; +} + +/** + * vdo_get_device_name() - Get the device name associated with the vdo target. + * @target: The target device interface. + * + * Return: The block device name. + */ +const char *vdo_get_device_name(const struct dm_target *target) +{ + return dm_device_name(dm_table_get_md(target->table)); +} + +/** + * vdo_synchronous_flush() - Issue a flush request and wait for it to complete. + * @vdo: The vdo. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_synchronous_flush(struct vdo *vdo) +{ + int result; + struct bio bio; + + bio_init(&bio, vdo_get_backing_device(vdo), 0, 0, + REQ_OP_WRITE | REQ_PREFLUSH); + submit_bio_wait(&bio); + result = blk_status_to_errno(bio.bi_status); + + atomic64_inc(&vdo->stats.flush_out); + if (result != 0) { + uds_log_error_strerror(result, "synchronous flush failed"); + result = -EIO; + } + + bio_uninit(&bio); + return result; +} + +/** + * vdo_get_state() - Get the current state of the vdo. + * @vdo: The vdo. + + * Context: This method may be called from any thread. + * + * Return: The current state of the vdo. + */ +enum vdo_state vdo_get_state(const struct vdo *vdo) +{ + enum vdo_state state = atomic_read(&vdo->state); + + /* pairs with barriers where state field is changed */ + smp_rmb(); + return state; +} + +/** + * vdo_set_state() - Set the current state of the vdo. + * @vdo: The vdo whose state is to be set. + * @state: The new state of the vdo. + * + * Context: This method may be called from any thread. + */ +void vdo_set_state(struct vdo *vdo, enum vdo_state state) +{ + /* pairs with barrier in vdo_get_state */ + smp_wmb(); + atomic_set(&vdo->state, state); +} + +/** + * vdo_get_admin_state() - Get the admin state of the vdo. + * @vdo: The vdo. + * + * Return: The code for the vdo's current admin state. + */ +const struct admin_state_code *vdo_get_admin_state(const struct vdo *vdo) +{ + return vdo_get_admin_state_code(&vdo->admin.state); +} + +/** + * record_vdo() - Record the state of the VDO for encoding in the super block. + */ +static void record_vdo(struct vdo *vdo) +{ + /* This is for backwards compatibility. */ + vdo->states.unused = vdo->geometry.unused; + vdo->states.vdo.state = vdo_get_state(vdo); + vdo->states.block_map = vdo_record_block_map(vdo->block_map); + vdo->states.recovery_journal = vdo_record_recovery_journal(vdo->recovery_journal); + vdo->states.slab_depot = vdo_record_slab_depot(vdo->depot); + vdo->states.layout = vdo->layout; +} + +/** + * continue_super_block_parent() - Continue the parent of a super block save operation. + * @completion: The super block vio. + * + * This callback is registered in vdo_save_components(). + */ +static void continue_super_block_parent(struct vdo_completion *completion) +{ + vdo_continue_completion(UDS_FORGET(completion->parent), completion->result); +} + +/** + * handle_save_error() - Log a super block save error. + * @completion: The super block vio. + * + * This error handler is registered in vdo_save_components(). + */ +static void handle_save_error(struct vdo_completion *completion) +{ + struct vdo_super_block *super_block = + container_of(as_vio(completion), struct vdo_super_block, vio); + + vio_record_metadata_io_error(&super_block->vio); + uds_log_error_strerror(completion->result, "super block save failed"); + /* + * Mark the super block as unwritable so that we won't attempt to write it again. This + * avoids the case where a growth attempt fails writing the super block with the new size, + * but the subsequent attempt to write out the read-only state succeeds. In this case, + * writes which happened just before the suspend would not be visible if the VDO is + * restarted without rebuilding, but, after a read-only rebuild, the effects of those + * writes would reappear. + */ + super_block->unwritable = true; + completion->callback(completion); +} + +static void super_block_write_endio(struct bio *bio) +{ + struct vio *vio = bio->bi_private; + struct vdo_completion *parent = vio->completion.parent; + + continue_vio_after_io(vio, continue_super_block_parent, parent->callback_thread_id); +} + +/** + * vdo_save_components() - Encode the vdo and save the super block asynchronously. + * @vdo: The vdo whose state is being saved. + * @parent: The completion to notify when the save is complete. + */ +void vdo_save_components(struct vdo *vdo, struct vdo_completion *parent) +{ + struct vdo_super_block *super_block = &vdo->super_block; + + if (super_block->unwritable) { + vdo_continue_completion(parent, VDO_READ_ONLY); + return; + } + + if (super_block->vio.completion.parent != NULL) { + vdo_continue_completion(parent, VDO_COMPONENT_BUSY); + return; + } + + record_vdo(vdo); + + vdo_encode_super_block(super_block->buffer, &vdo->states); + super_block->vio.completion.parent = parent; + super_block->vio.completion.callback_thread_id = parent->callback_thread_id; + submit_metadata_vio(&super_block->vio, + vdo_get_data_region_start(vdo->geometry), + super_block_write_endio, + handle_save_error, + REQ_OP_WRITE | REQ_PREFLUSH | REQ_FUA); +} + +/** + * vdo_register_read_only_listener() - Register a listener to be notified when the VDO goes + * read-only. + * @vdo: The vdo to register with. + * @listener: The object to notify. + * @notification: The function to call to send the notification. + * @thread_id: The id of the thread on which to send the notification. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_register_read_only_listener(struct vdo *vdo, + void *listener, + vdo_read_only_notification *notification, + thread_id_t thread_id) +{ + struct vdo_thread *thread = &vdo->threads[thread_id]; + struct read_only_listener *read_only_listener; + int result; + + result = ASSERT(thread_id != vdo->thread_config.dedupe_thread, + "read only listener not registered on dedupe thread"); + if (result != VDO_SUCCESS) + return result; + + result = UDS_ALLOCATE(1, struct read_only_listener, __func__, &read_only_listener); + if (result != VDO_SUCCESS) + return result; + + *read_only_listener = (struct read_only_listener) { + .listener = listener, + .notify = notification, + .next = thread->listeners, + }; + + thread->listeners = read_only_listener; + return VDO_SUCCESS; +} + +/** + * notify_vdo_of_read_only_mode() - Notify a vdo that it is going read-only. + * @listener: The vdo. + * @parent: The completion to notify in order to acknowledge the notification. + * + * This will save the read-only state to the super block. + * + * Implements vdo_read_only_notification. + */ +static void notify_vdo_of_read_only_mode(void *listener, struct vdo_completion *parent) +{ + struct vdo *vdo = listener; + + if (vdo_in_read_only_mode(vdo)) + vdo_finish_completion(parent); + + vdo_set_state(vdo, VDO_READ_ONLY_MODE); + vdo_save_components(vdo, parent); +} + +/** + * vdo_enable_read_only_entry() - Enable a vdo to enter read-only mode on errors. + * @vdo: The vdo to enable. + * + * Return: VDO_SUCCESS or an error. + */ +int vdo_enable_read_only_entry(struct vdo *vdo) +{ + thread_id_t id; + bool is_read_only = vdo_in_read_only_mode(vdo); + struct read_only_notifier *notifier = &vdo->read_only_notifier; + + if (is_read_only) { + notifier->read_only_error = VDO_READ_ONLY; + notifier->state = NOTIFIED; + } else { + notifier->state = MAY_NOT_NOTIFY; + } + + spin_lock_init(¬ifier->lock); + vdo_initialize_completion(¬ifier->completion, vdo, VDO_READ_ONLY_MODE_COMPLETION); + + for (id = 0; id < vdo->thread_config.thread_count; id++) + vdo->threads[id].is_read_only = is_read_only; + + return vdo_register_read_only_listener(vdo, + vdo, + notify_vdo_of_read_only_mode, + vdo->thread_config.admin_thread); +} + +/** + * vdo_wait_until_not_entering_read_only_mode() - Wait until no read-only notifications are in + * progress and prevent any subsequent + * notifications. + * @parent: The completion to notify when no threads are entering read-only mode. + * + * Notifications may be re-enabled by calling vdo_allow_read_only_mode_entry(). + */ +void vdo_wait_until_not_entering_read_only_mode(struct vdo_completion *parent) +{ + struct vdo *vdo = parent->vdo; + struct read_only_notifier *notifier = &vdo->read_only_notifier; + + vdo_assert_on_admin_thread(vdo, __func__); + + if (notifier->waiter != NULL) { + vdo_continue_completion(parent, VDO_COMPONENT_BUSY); + return; + } + + spin_lock(¬ifier->lock); + if (notifier->state == NOTIFYING) + notifier->waiter = parent; + else if (notifier->state == MAY_NOTIFY) + notifier->state = MAY_NOT_NOTIFY; + spin_unlock(¬ifier->lock); + + if (notifier->waiter == NULL) { + /* + * A notification was not in progress, and now they are + * disallowed. + */ + vdo_launch_completion(parent); + return; + } +} + +/** + * as_notifier() - Convert a generic vdo_completion to a read_only_notifier. + * @completion: The completion to convert. + * + * Return: The completion as a read_only_notifier. + */ +static inline struct read_only_notifier *as_notifier(struct vdo_completion *completion) +{ + vdo_assert_completion_type(completion, VDO_READ_ONLY_MODE_COMPLETION); + return container_of(completion, struct read_only_notifier, completion); +} + +/** + * finish_entering_read_only_mode() - Complete the process of entering read only mode. + * @completion: The read-only mode completion. + */ +static void finish_entering_read_only_mode(struct vdo_completion *completion) +{ + struct read_only_notifier *notifier = as_notifier(completion); + + vdo_assert_on_admin_thread(completion->vdo, __func__); + + spin_lock(¬ifier->lock); + notifier->state = NOTIFIED; + spin_unlock(¬ifier->lock); + + if (notifier->waiter != NULL) + vdo_continue_completion(UDS_FORGET(notifier->waiter), completion->result); +} + +/** + * make_thread_read_only() - Inform each thread that the VDO is in read-only mode. + * @completion: The read-only mode completion. + */ +static void make_thread_read_only(struct vdo_completion *completion) +{ + struct vdo *vdo = completion->vdo; + thread_id_t thread_id = completion->callback_thread_id; + struct read_only_notifier *notifier = as_notifier(completion); + struct read_only_listener *listener = completion->parent; + + if (listener == NULL) { + /* This is the first call on this thread */ + struct vdo_thread *thread = &vdo->threads[thread_id]; + + thread->is_read_only = true; + listener = thread->listeners; + if (thread_id == 0) + uds_log_error_strerror(READ_ONCE(notifier->read_only_error), + "Unrecoverable error, entering read-only mode"); + } else { + /* We've just finished notifying a listener */ + listener = listener->next; + } + + if (listener != NULL) { + /* We have a listener to notify */ + vdo_prepare_completion(completion, + make_thread_read_only, + make_thread_read_only, + thread_id, + listener); + listener->notify(listener->listener, completion); + return; + } + + /* We're done with this thread */ + if (++thread_id == vdo->thread_config.dedupe_thread) + /* + * We don't want to notify the dedupe thread since it may be + * blocked rebuilding the index. + */ + ++thread_id; + + if (thread_id >= vdo->thread_config.thread_count) + /* There are no more threads */ + vdo_prepare_completion(completion, + finish_entering_read_only_mode, + finish_entering_read_only_mode, + vdo->thread_config.admin_thread, + NULL); + else + vdo_prepare_completion(completion, + make_thread_read_only, + make_thread_read_only, + thread_id, + NULL); + + vdo_launch_completion(completion); +} + +/** + * vdo_allow_read_only_mode_entry() - Allow the notifier to put the VDO into read-only mode, + * reversing the effects of + * vdo_wait_until_not_entering_read_only_mode(). + * @parent: The object to notify once the operation is complete. + * + * If some thread tried to put the vdo into read-only mode while notifications were disallowed, it + * will be done when this method is called. If that happens, the parent will not be notified until + * the vdo has actually entered read-only mode and attempted to save the super block. + * + * Context: This method may only be called from the admin thread. + */ +void vdo_allow_read_only_mode_entry(struct vdo_completion *parent) +{ + struct vdo *vdo = parent->vdo; + struct read_only_notifier *notifier = &vdo->read_only_notifier; + + vdo_assert_on_admin_thread(vdo, __func__); + + if (notifier->waiter != NULL) { + vdo_continue_completion(parent, VDO_COMPONENT_BUSY); + return; + } + + spin_lock(¬ifier->lock); + if (notifier->state == MAY_NOT_NOTIFY) { + if (notifier->read_only_error == VDO_SUCCESS) { + notifier->state = MAY_NOTIFY; + } else { + notifier->state = NOTIFYING; + notifier->waiter = parent; + } + } + spin_unlock(¬ifier->lock); + + if (notifier->waiter == NULL) { + /* We're done */ + vdo_launch_completion(parent); + return; + } + + /* Do the pending notification. */ + make_thread_read_only(¬ifier->completion); +} + +/** + * vdo_enter_read_only_mode() - Put a VDO into read-only mode and save the read-only state in the + * super block. + * @vdo: The vdo. + * @error_code: The error which caused the VDO to enter read-only mode. + * + * This method is a no-op if the VDO is already read-only. + */ +void vdo_enter_read_only_mode(struct vdo *vdo, int error_code) +{ + bool notify = false; + thread_id_t thread_id = vdo_get_callback_thread_id(); + struct read_only_notifier *notifier = &vdo->read_only_notifier; + struct vdo_thread *thread; + + if (thread_id != VDO_INVALID_THREAD_ID) { + thread = &vdo->threads[thread_id]; + if (thread->is_read_only) + /* This thread has already gone read-only. */ + return; + + /* Record for this thread that the VDO is read-only. */ + thread->is_read_only = true; + } + + spin_lock(¬ifier->lock); + if (notifier->read_only_error == VDO_SUCCESS) { + WRITE_ONCE(notifier->read_only_error, error_code); + if (notifier->state == MAY_NOTIFY) { + notifier->state = NOTIFYING; + notify = true; + } + } + spin_unlock(¬ifier->lock); + + if (!notify) + /* The notifier is already aware of a read-only error */ + return; + + /* Initiate a notification starting on the lowest numbered thread. */ + vdo_launch_completion_callback(¬ifier->completion, make_thread_read_only, 0); +} + +/** + * vdo_is_read_only() - Check whether the VDO is read-only. + * @vdo: The vdo. + * + * Return: true if the vdo is read-only. + * + * This method may be called from any thread, as opposed to examining the VDO's state field which + * is only safe to check from the admin thread. + */ +bool vdo_is_read_only(struct vdo *vdo) +{ + return vdo->threads[vdo_get_callback_thread_id()].is_read_only; +} + +/** + * vdo_in_read_only_mode() - Check whether a vdo is in read-only mode. + * @vdo: The vdo to query. + * + * Return: true if the vdo is in read-only mode. + */ +bool vdo_in_read_only_mode(const struct vdo *vdo) +{ + return (vdo_get_state(vdo) == VDO_READ_ONLY_MODE); +} + +/** + * vdo_in_recovery_mode() - Check whether the vdo is in recovery mode. + * @vdo: The vdo to query. + * + * Return: true if the vdo is in recovery mode. + */ +bool vdo_in_recovery_mode(const struct vdo *vdo) +{ + return (vdo_get_state(vdo) == VDO_RECOVERING); +} + +/** + * vdo_enter_recovery_mode() - Put the vdo into recovery mode. + * @vdo: The vdo. + */ +void vdo_enter_recovery_mode(struct vdo *vdo) +{ + vdo_assert_on_admin_thread(vdo, __func__); + + if (vdo_in_read_only_mode(vdo)) + return; + + uds_log_info("Entering recovery mode"); + vdo_set_state(vdo, VDO_RECOVERING); +} + +/** + * complete_synchronous_action() - Signal the waiting thread that a synchronous action is complete. + * @completion: The sync completion. + */ +static void complete_synchronous_action(struct vdo_completion *completion) +{ + vdo_assert_completion_type(completion, VDO_SYNC_COMPLETION); + complete(&(container_of(completion, struct sync_completion, vdo_completion)->completion)); +} + +/** + * perform_synchronous_action() - Launch an action on a VDO thread and wait for it to complete. + * @vdo: The vdo. + * @action: The callback to launch. + * @thread_id: The thread on which to run the action. + * @parent: The parent of the sync completion (may be NULL). + */ +static int perform_synchronous_action(struct vdo *vdo, + vdo_action *action, + thread_id_t thread_id, + void *parent) +{ + struct sync_completion sync; + + vdo_initialize_completion(&sync.vdo_completion, vdo, VDO_SYNC_COMPLETION); + init_completion(&sync.completion); + sync.vdo_completion.parent = parent; + vdo_launch_completion_callback(&sync.vdo_completion, action, thread_id); + wait_for_completion(&sync.completion); + return sync.vdo_completion.result; +} + +/** + * set_compression_callback() - Callback to turn compression on or off. + * @completion: The completion. + */ +static void set_compression_callback(struct vdo_completion *completion) +{ + struct vdo *vdo = completion->vdo; + bool *enable = completion->parent; + bool was_enabled = vdo_get_compressing(vdo); + + if (*enable != was_enabled) { + WRITE_ONCE(vdo->compressing, *enable); + if (was_enabled) + /* Signal the packer to flush since compression has been disabled. */ + vdo_flush_packer(vdo->packer); + } + + uds_log_info("compression is %s", (*enable ? "enabled" : "disabled")); + *enable = was_enabled; + complete_synchronous_action(completion); +} + +/** + * vdo_set_compressing() - Turn compression on or off. + * @vdo: The vdo. + * @enable: Whether to enable or disable compression. + * + * Return: Whether compression was previously on or off. + */ +bool vdo_set_compressing(struct vdo *vdo, bool enable) +{ + perform_synchronous_action(vdo, + set_compression_callback, + vdo->thread_config.packer_thread, + &enable); + return enable; +} + +/** + * vdo_get_compressing() - Get whether compression is enabled in a vdo. + * @vdo: The vdo. + * + * Return: State of compression. + */ +bool vdo_get_compressing(struct vdo *vdo) +{ + return READ_ONCE(vdo->compressing); +} + +static size_t get_block_map_cache_size(const struct vdo *vdo) +{ + return ((size_t) vdo->device_config->cache_size) * VDO_BLOCK_SIZE; +} + +static struct error_statistics __must_check get_vdo_error_statistics(const struct vdo *vdo) +{ + /* + * The error counts can be incremented from arbitrary threads and so must be incremented + * atomically, but they are just statistics with no semantics that could rely on memory + * order, so unfenced reads are sufficient. + */ + const struct atomic_statistics *atoms = &vdo->stats; + + return (struct error_statistics) { + .invalid_advice_pbn_count = atomic64_read(&atoms->invalid_advice_pbn_count), + .no_space_error_count = atomic64_read(&atoms->no_space_error_count), + .read_only_error_count = atomic64_read(&atoms->read_only_error_count), + }; +} + +static void copy_bio_stat(struct bio_stats *b, const struct atomic_bio_stats *a) +{ + b->read = atomic64_read(&a->read); + b->write = atomic64_read(&a->write); + b->discard = atomic64_read(&a->discard); + b->flush = atomic64_read(&a->flush); + b->empty_flush = atomic64_read(&a->empty_flush); + b->fua = atomic64_read(&a->fua); +} + +static struct bio_stats subtract_bio_stats(struct bio_stats minuend, struct bio_stats subtrahend) +{ + return (struct bio_stats) { + .read = minuend.read - subtrahend.read, + .write = minuend.write - subtrahend.write, + .discard = minuend.discard - subtrahend.discard, + .flush = minuend.flush - subtrahend.flush, + .empty_flush = minuend.empty_flush - subtrahend.empty_flush, + .fua = minuend.fua - subtrahend.fua, + }; +} + +/** + * vdo_get_physical_blocks_allocated() - Get the number of physical blocks in use by user data. + * @vdo: The vdo. + * + * Return: The number of blocks allocated for user data. + */ +static block_count_t __must_check vdo_get_physical_blocks_allocated(const struct vdo *vdo) +{ + return (vdo_get_slab_depot_allocated_blocks(vdo->depot) - + vdo_get_journal_block_map_data_blocks_used(vdo->recovery_journal)); +} + +/** + * vdo_get_physical_blocks_overhead() - Get the number of physical blocks used by vdo metadata. + * @vdo: The vdo. + * + * Return: The number of overhead blocks. + */ +static block_count_t __must_check vdo_get_physical_blocks_overhead(const struct vdo *vdo) +{ + /* + * config.physical_blocks is mutated during resize and is in a packed structure, + * but resize runs on admin thread. + * TODO: Verify that this is always safe. + */ + return (vdo->states.vdo.config.physical_blocks - + vdo_get_slab_depot_data_blocks(vdo->depot) + + vdo_get_journal_block_map_data_blocks_used(vdo->recovery_journal)); +} + +static const char *vdo_describe_state(enum vdo_state state) +{ + /* These strings should all fit in the 15 chars of VDOStatistics.mode. */ + switch (state) { + case VDO_RECOVERING: + return "recovering"; + + case VDO_READ_ONLY_MODE: + return "read-only"; + + default: + return "normal"; + } +} + +/** + * get_vdo_statistics() - Populate a vdo_statistics structure on the admin thread. + * @vdo: The vdo. + * @stats: The statistics structure to populate. + */ +static void get_vdo_statistics(const struct vdo *vdo, struct vdo_statistics *stats) +{ + struct recovery_journal *journal = vdo->recovery_journal; + enum vdo_state state = vdo_get_state(vdo); + + vdo_assert_on_admin_thread(vdo, __func__); + + /* start with a clean slate */ + memset(stats, 0, sizeof(struct vdo_statistics)); + + /* + * These are immutable properties of the vdo object, so it is safe to query them from any + * thread. + */ + stats->version = STATISTICS_VERSION; + stats->logical_blocks = vdo->states.vdo.config.logical_blocks; + /* + * config.physical_blocks is mutated during resize and is in a packed structure, but resize + * runs on the admin thread. + * TODO: verify that this is always safe + */ + stats->physical_blocks = vdo->states.vdo.config.physical_blocks; + stats->block_size = VDO_BLOCK_SIZE; + stats->complete_recoveries = vdo->states.vdo.complete_recoveries; + stats->read_only_recoveries = vdo->states.vdo.read_only_recoveries; + stats->block_map_cache_size = get_block_map_cache_size(vdo); + + /* The callees are responsible for thread-safety. */ + stats->data_blocks_used = vdo_get_physical_blocks_allocated(vdo); + stats->overhead_blocks_used = vdo_get_physical_blocks_overhead(vdo); + stats->logical_blocks_used = vdo_get_recovery_journal_logical_blocks_used(journal); + vdo_get_slab_depot_statistics(vdo->depot, stats); + stats->journal = vdo_get_recovery_journal_statistics(journal); + stats->packer = vdo_get_packer_statistics(vdo->packer); + stats->block_map = vdo_get_block_map_statistics(vdo->block_map); + vdo_get_dedupe_statistics(vdo->hash_zones, stats); + stats->errors = get_vdo_error_statistics(vdo); + stats->in_recovery_mode = (state == VDO_RECOVERING); + snprintf(stats->mode, sizeof(stats->mode), "%s", vdo_describe_state(state)); + + stats->instance = vdo->instance; + stats->current_vios_in_progress = get_data_vio_pool_active_requests(vdo->data_vio_pool); + stats->max_vios = get_data_vio_pool_maximum_requests(vdo->data_vio_pool); + + stats->flush_out = atomic64_read(&vdo->stats.flush_out); + stats->logical_block_size = vdo->device_config->logical_block_size; + copy_bio_stat(&stats->bios_in, &vdo->stats.bios_in); + copy_bio_stat(&stats->bios_in_partial, &vdo->stats.bios_in_partial); + copy_bio_stat(&stats->bios_out, &vdo->stats.bios_out); + copy_bio_stat(&stats->bios_meta, &vdo->stats.bios_meta); + copy_bio_stat(&stats->bios_journal, &vdo->stats.bios_journal); + copy_bio_stat(&stats->bios_page_cache, &vdo->stats.bios_page_cache); + copy_bio_stat(&stats->bios_out_completed, &vdo->stats.bios_out_completed); + copy_bio_stat(&stats->bios_meta_completed, &vdo->stats.bios_meta_completed); + copy_bio_stat(&stats->bios_journal_completed, &vdo->stats.bios_journal_completed); + copy_bio_stat(&stats->bios_page_cache_completed, &vdo->stats.bios_page_cache_completed); + copy_bio_stat(&stats->bios_acknowledged, &vdo->stats.bios_acknowledged); + copy_bio_stat(&stats->bios_acknowledged_partial, &vdo->stats.bios_acknowledged_partial); + stats->bios_in_progress = subtract_bio_stats(stats->bios_in, stats->bios_acknowledged); + uds_get_memory_stats(&stats->memory_usage.bytes_used, + &stats->memory_usage.peak_bytes_used); +} + +/** + * vdo_fetch_statistics_callback() - Action to populate a vdo_statistics + * structure on the admin thread. + * @completion: The completion. + * + * This callback is registered in vdo_fetch_statistics(). + */ +static void vdo_fetch_statistics_callback(struct vdo_completion *completion) +{ + get_vdo_statistics(completion->vdo, completion->parent); + complete_synchronous_action(completion); +} + +/** + * vdo_fetch_statistics() - Fetch statistics on the correct thread. + * @vdo: The vdo. + * @stats: The vdo statistics are returned here. + */ +void vdo_fetch_statistics(struct vdo *vdo, struct vdo_statistics *stats) +{ + perform_synchronous_action(vdo, + vdo_fetch_statistics_callback, + vdo->thread_config.admin_thread, + stats); +} + +/** + * vdo_get_callback_thread_id() - Get the id of the callback thread on which a completion is + * currently running. + * + * Return: The current thread ID, or -1 if no such thread. + */ +thread_id_t vdo_get_callback_thread_id(void) +{ + struct vdo_work_queue *queue = vdo_get_current_work_queue(); + struct vdo_thread *thread; + thread_id_t thread_id; + + if (queue == NULL) + return VDO_INVALID_THREAD_ID; + + thread = vdo_get_work_queue_owner(queue); + thread_id = thread->thread_id; + + if (PARANOID_THREAD_CONSISTENCY_CHECKS) { + BUG_ON(thread_id >= thread->vdo->thread_config.thread_count); + BUG_ON(thread != &thread->vdo->threads[thread_id]); + } + + return thread_id; +} + +/** + * vdo_dump_status() - Dump status information about a vdo to the log for debugging. + * @vdo: The vdo to dump. + */ +void vdo_dump_status(const struct vdo *vdo) +{ + zone_count_t zone; + + vdo_dump_flusher(vdo->flusher); + vdo_dump_recovery_journal_statistics(vdo->recovery_journal); + vdo_dump_packer(vdo->packer); + vdo_dump_slab_depot(vdo->depot); + + for (zone = 0; zone < vdo->thread_config.logical_zone_count; zone++) + vdo_dump_logical_zone(&vdo->logical_zones->zones[zone]); + + for (zone = 0; zone < vdo->thread_config.physical_zone_count; zone++) + vdo_dump_physical_zone(&vdo->physical_zones->zones[zone]); + + vdo_dump_hash_zones(vdo->hash_zones); +} + +/** + * vdo_assert_on_admin_thread() - Assert that we are running on the admin thread. + * @vdo: The vdo. + * @name: The name of the function which should be running on the admin thread (for logging). + */ +void vdo_assert_on_admin_thread(const struct vdo *vdo, const char *name) +{ + ASSERT_LOG_ONLY((vdo_get_callback_thread_id() == vdo->thread_config.admin_thread), + "%s called on admin thread", + name); +} + +/** + * vdo_assert_on_logical_zone_thread() - Assert that this function was called on the specified + * logical zone thread. + * @vdo: The vdo. + * @logical_zone: The number of the logical zone. + * @name: The name of the calling function. + */ +void vdo_assert_on_logical_zone_thread(const struct vdo *vdo, + zone_count_t logical_zone, + const char *name) +{ + ASSERT_LOG_ONLY((vdo_get_callback_thread_id() == + vdo->thread_config.logical_threads[logical_zone]), + "%s called on logical thread", + name); +} + +/** + * vdo_assert_on_physical_zone_thread() - Assert that this function was called on the specified + * physical zone thread. + * @vdo: The vdo. + * @physical_zone: The number of the physical zone. + * @name: The name of the calling function. + */ +void vdo_assert_on_physical_zone_thread(const struct vdo *vdo, + zone_count_t physical_zone, + const char *name) +{ + ASSERT_LOG_ONLY((vdo_get_callback_thread_id() == + vdo->thread_config.physical_threads[physical_zone]), + "%s called on physical thread", + name); +} + +/** + * vdo_get_physical_zone() - Get the physical zone responsible for a given physical block number. + * @vdo: The vdo containing the physical zones. + * @pbn: The PBN of the data block. + * @zone_ptr: A pointer to return the physical zone. + * + * Gets the physical zone responsible for a given physical block number of a data block in this vdo + * instance, or of the zero block (for which a NULL zone is returned). For any other block number + * that is not in the range of valid data block numbers in any slab, an error will be returned. + * This function is safe to call on invalid block numbers; it will not put the vdo into read-only + * mode. + * + * Return: VDO_SUCCESS or VDO_OUT_OF_RANGE if the block number is invalid or an error code for any + * other failure. + */ +int vdo_get_physical_zone(const struct vdo *vdo, + physical_block_number_t pbn, + struct physical_zone **zone_ptr) +{ + struct vdo_slab *slab; + int result; + + if (pbn == VDO_ZERO_BLOCK) { + *zone_ptr = NULL; + return VDO_SUCCESS; + } + + /* + * Used because it does a more restrictive bounds check than vdo_get_slab(), and done first + * because it won't trigger read-only mode on an invalid PBN. + */ + if (!vdo_is_physical_data_block(vdo->depot, pbn)) + return VDO_OUT_OF_RANGE; + + /* With the PBN already checked, we should always succeed in finding a slab. */ + slab = vdo_get_slab(vdo->depot, pbn); + result = ASSERT(slab != NULL, "vdo_get_slab must succeed on all valid PBNs"); + if (result != VDO_SUCCESS) + return result; + + *zone_ptr = &vdo->physical_zones->zones[slab->allocator->zone_number]; + return VDO_SUCCESS; +} diff --git a/drivers/md/dm-vdo/vdo.h b/drivers/md/dm-vdo/vdo.h new file mode 100644 index 000000000000..a2caf54221c8 --- /dev/null +++ b/drivers/md/dm-vdo/vdo.h @@ -0,0 +1,381 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2023 Red Hat + */ + +#ifndef VDO_H +#define VDO_H + +#include +#include +#include +#include +#include +#include +#include + +#include "admin-state.h" +#include "encodings.h" +#include "packer.h" +#include "physical-zone.h" +#include "statistics.h" +#include "thread-registry.h" +#include "types.h" +#include "uds.h" +#include "work-queue.h" + +enum notifier_state { + /** Notifications are allowed but not in progress */ + MAY_NOTIFY, + /** A notification is in progress */ + NOTIFYING, + /** Notifications are not allowed */ + MAY_NOT_NOTIFY, + /** A notification has completed */ + NOTIFIED, +}; + +/** + * typedef vdo_read_only_notification - A function to notify a listener that the VDO has gone + * read-only. + * @listener: The object to notify. + * @parent: The completion to notify in order to acknowledge the notification. + */ +typedef void vdo_read_only_notification(void *listener, struct vdo_completion *parent); + +/* + * An object to be notified when the VDO enters read-only mode + */ +struct read_only_listener { + /* The listener */ + void *listener; + /* The method to call to notify the listener */ + vdo_read_only_notification *notify; + /* A pointer to the next listener */ + struct read_only_listener *next; +}; + +struct vdo_thread { + struct vdo *vdo; + thread_id_t thread_id; + struct vdo_work_queue *queue; + /* + * Each thread maintains its own notion of whether the VDO is read-only so that the + * read-only state can be checked from any base thread without worrying about + * synchronization or thread safety. This does mean that knowledge of the VDO going + * read-only does not occur simultaneously across the VDO's threads, but that does not seem + * to cause any problems. + */ + bool is_read_only; + /* + * A list of objects waiting to be notified on this thread that the VDO has entered + * read-only mode. + */ + struct read_only_listener *listeners; + struct registered_thread allocating_thread; +}; + +/* Keep struct bio statistics atomically */ +struct atomic_bio_stats { + atomic64_t read; /* Number of not REQ_WRITE bios */ + atomic64_t write; /* Number of REQ_WRITE bios */ + atomic64_t discard; /* Number of REQ_DISCARD bios */ + atomic64_t flush; /* Number of REQ_FLUSH bios */ + atomic64_t empty_flush; /* Number of REQ_PREFLUSH bios without data */ + atomic64_t fua; /* Number of REQ_FUA bios */ +}; + +/* Counters are atomic since updates can arrive concurrently from arbitrary threads. */ +struct atomic_statistics { + atomic64_t bios_submitted; + atomic64_t bios_completed; + atomic64_t flush_out; + atomic64_t invalid_advice_pbn_count; + atomic64_t no_space_error_count; + atomic64_t read_only_error_count; + struct atomic_bio_stats bios_in; + struct atomic_bio_stats bios_in_partial; + struct atomic_bio_stats bios_out; + struct atomic_bio_stats bios_out_completed; + struct atomic_bio_stats bios_acknowledged; + struct atomic_bio_stats bios_acknowledged_partial; + struct atomic_bio_stats bios_meta; + struct atomic_bio_stats bios_meta_completed; + struct atomic_bio_stats bios_journal; + struct atomic_bio_stats bios_journal_completed; + struct atomic_bio_stats bios_page_cache; + struct atomic_bio_stats bios_page_cache_completed; +}; + +struct read_only_notifier { + /* The completion for entering read-only mode */ + struct vdo_completion completion; + /* A completion waiting for notifications to be drained or enabled */ + struct vdo_completion *waiter; + /* Lock to protect the next two fields */ + spinlock_t lock; + /* The code of the error which put the VDO into read-only mode */ + int read_only_error; + /* The current state of the notifier (values described above) */ + enum notifier_state state; +}; + +/* + * The thread ID returned when the current thread is not a vdo thread, or can not be determined + * (usually due to being at interrupt context). + */ +#define VDO_INVALID_THREAD_ID ((thread_id_t) -1) + +struct thread_config { + zone_count_t logical_zone_count; + zone_count_t physical_zone_count; + zone_count_t hash_zone_count; + thread_count_t bio_thread_count; + thread_count_t thread_count; + thread_id_t admin_thread; + thread_id_t journal_thread; + thread_id_t packer_thread; + thread_id_t dedupe_thread; + thread_id_t bio_ack_thread; + thread_id_t cpu_thread; + thread_id_t *logical_threads; + thread_id_t *physical_threads; + thread_id_t *hash_zone_threads; + thread_id_t *bio_threads; +}; + +struct thread_count_config; + +struct vdo_super_block { + /* The vio for reading and writing the super block to disk */ + struct vio vio; + /* A buffer to hold the super block */ + u8 *buffer; + /* Whether this super block may not be written */ + bool unwritable; +}; + +struct data_vio_pool; + +struct vdo_administrator { + struct vdo_completion completion; + struct admin_state state; + atomic_t busy; + u32 phase; + struct completion callback_sync; +}; + +struct vdo { + char thread_name_prefix[MAX_VDO_WORK_QUEUE_NAME_LEN]; + struct vdo_thread *threads; + vdo_action *action; + struct vdo_completion *completion; + struct vio_tracer *vio_tracer; + + /* The atomic version of the state of this vdo */ + atomic_t state; + /* The full state of all components */ + struct vdo_component_states states; + /* + * A counter value to attach to thread names and log messages to identify the individual + * device. + */ + unsigned int instance; + /* The read-only notifier */ + struct read_only_notifier read_only_notifier; + /* The load-time configuration of this vdo */ + struct device_config *device_config; + /* The thread mapping */ + struct thread_config thread_config; + + /* The super block */ + struct vdo_super_block super_block; + + /* The partitioning of the underlying storage */ + struct layout layout; + struct layout next_layout; + struct dm_kcopyd_client *partition_copier; + + /* The block map */ + struct block_map *block_map; + + /* The journal for block map recovery */ + struct recovery_journal *recovery_journal; + + /* The slab depot */ + struct slab_depot *depot; + + /* The compressed-block packer */ + struct packer *packer; + /* Whether incoming data should be compressed */ + bool compressing; + + /* The handler for flush requests */ + struct flusher *flusher; + + /* The state the vdo was in when loaded (primarily for unit tests) */ + enum vdo_state load_state; + + /* The logical zones of this vdo */ + struct logical_zones *logical_zones; + + /* The physical zones of this vdo */ + struct physical_zones *physical_zones; + + /* The hash lock zones of this vdo */ + struct hash_zones *hash_zones; + + /* Bio submission manager used for sending bios to the storage device. */ + struct io_submitter *io_submitter; + + /* The pool of data_vios for servicing incoming bios */ + struct data_vio_pool *data_vio_pool; + + /* The manager for administrative operations */ + struct vdo_administrator admin; + + /* Flags controlling administrative operations */ + const struct admin_state_code *suspend_type; + bool allocations_allowed; + bool dump_on_shutdown; + atomic_t processing_message; + + /* + * Statistics + * Atomic stats counters + */ + struct atomic_statistics stats; + /* Used to gather statistics without allocating memory */ + struct vdo_statistics stats_buffer; + /* Protects the stats_buffer */ + struct mutex stats_mutex; + /* true if sysfs directory is set up */ + bool sysfs_added; + /* Used when shutting down the sysfs statistics */ + struct completion stats_shutdown; + + + /* A list of all device_configs referencing this vdo */ + struct list_head device_config_list; + + /* This VDO's list entry for the device registry */ + struct list_head registration; + + /* Underlying block device info. */ + u64 starting_sector_offset; + struct volume_geometry geometry; + + /* For sysfs */ + struct kobject vdo_directory; + struct kobject stats_directory; + + /* N blobs of context data for LZ4 code, one per CPU thread. */ + char **compression_context; +}; + + +/** + * vdo_uses_bio_ack_queue() - Indicate whether the vdo is configured to use a separate work queue + * for acknowledging received and processed bios. + * @vdo: The vdo. + * + * Note that this directly controls the handling of write operations, but the compile-time flag + * VDO_USE_BIO_ACK_QUEUE_FOR_READ is also checked for read operations. + * + * Return: Whether a bio-acknowledgement work queue is in use. + */ +static inline bool vdo_uses_bio_ack_queue(struct vdo *vdo) +{ + return vdo->device_config->thread_counts.bio_ack_threads > 0; +} + +/** + * typedef vdo_filter_t - Method type for vdo matching methods. + * + * A filter function returns false if the vdo doesn't match. + */ +typedef bool vdo_filter_t(struct vdo *vdo, const void *context); + +void vdo_initialize_device_registry_once(void); +struct vdo * __must_check vdo_find_matching(vdo_filter_t *filter, const void *context); + +int __must_check vdo_make_thread(struct vdo *vdo, + thread_id_t thread_id, + const struct vdo_work_queue_type *type, + unsigned int queue_count, + void *contexts[]); + +static inline int __must_check vdo_make_default_thread(struct vdo *vdo, thread_id_t thread_id) +{ + return vdo_make_thread(vdo, thread_id, NULL, 1, NULL); +} + +int __must_check +vdo_make(unsigned int instance, struct device_config *config, char **reason, struct vdo **vdo_ptr); + +void vdo_destroy(struct vdo *vdo); + +void vdo_load_super_block(struct vdo *vdo, struct vdo_completion *parent); + +int __must_check vdo_add_sysfs_stats_dir(struct vdo *vdo); + +struct block_device * __must_check vdo_get_backing_device(const struct vdo *vdo); + +const char * __must_check vdo_get_device_name(const struct dm_target *target); + +int __must_check vdo_synchronous_flush(struct vdo *vdo); + +const struct admin_state_code * __must_check vdo_get_admin_state(const struct vdo *vdo); + +bool vdo_set_compressing(struct vdo *vdo, bool enable); + +bool vdo_get_compressing(struct vdo *vdo); + +void vdo_fetch_statistics(struct vdo *vdo, struct vdo_statistics *stats); + +thread_id_t vdo_get_callback_thread_id(void); + +enum vdo_state __must_check vdo_get_state(const struct vdo *vdo); + +void vdo_set_state(struct vdo *vdo, enum vdo_state state); + +void vdo_save_components(struct vdo *vdo, struct vdo_completion *parent); + +int vdo_register_read_only_listener(struct vdo *vdo, + void *listener, + vdo_read_only_notification *notification, + thread_id_t thread_id); + +int vdo_enable_read_only_entry(struct vdo *vdo); + +void vdo_wait_until_not_entering_read_only_mode(struct vdo_completion *parent); + +void vdo_allow_read_only_mode_entry(struct vdo_completion *parent); + +void vdo_enter_read_only_mode(struct vdo *vdo, int error_code); + +bool __must_check vdo_is_read_only(struct vdo *vdo); + +bool __must_check vdo_in_read_only_mode(const struct vdo *vdo); + +bool __must_check vdo_in_recovery_mode(const struct vdo *vdo); + +void vdo_enter_recovery_mode(struct vdo *vdo); + +void vdo_assert_on_admin_thread(const struct vdo *vdo, const char *name); + +void vdo_assert_on_logical_zone_thread(const struct vdo *vdo, + zone_count_t logical_zone, + const char *name); + +void vdo_assert_on_physical_zone_thread(const struct vdo *vdo, + zone_count_t physical_zone, + const char *name); + +int __must_check vdo_get_physical_zone(const struct vdo *vdo, + physical_block_number_t pbn, + struct physical_zone **zone_ptr); + +void vdo_dump_status(const struct vdo *vdo); + +#endif /* VDO_H */