Signed-off-by: J. corwin Coburn <corwin@xxxxxxxxxx> --- drivers/md/dm-vdo/dedupe.c | 622 +++++++++++++++++++++++++++++++++++++ drivers/md/dm-vdo/dedupe.h | 26 ++ 2 files changed, 648 insertions(+) diff --git a/drivers/md/dm-vdo/dedupe.c b/drivers/md/dm-vdo/dedupe.c index 18c7509ef90..6ffecabd772 100644 --- a/drivers/md/dm-vdo/dedupe.c +++ b/drivers/md/dm-vdo/dedupe.c @@ -143,6 +143,48 @@ #include "vdo.h" #include "wait-queue.h" +struct uds_attribute { + struct attribute attr; + const char *(*show_string)(struct hash_zones *hash_zones); +}; + +enum timer_state { + DEDUPE_QUERY_TIMER_IDLE, + DEDUPE_QUERY_TIMER_RUNNING, + DEDUPE_QUERY_TIMER_FIRED, +}; + +enum dedupe_context_state { + DEDUPE_CONTEXT_IDLE, + DEDUPE_CONTEXT_PENDING, + DEDUPE_CONTEXT_TIMED_OUT, + DEDUPE_CONTEXT_COMPLETE, + DEDUPE_CONTEXT_TIMED_OUT_COMPLETE, +}; + +/* Possible index states: closed, opened, or transitioning between those two. */ +enum index_state { + IS_CLOSED, + IS_CHANGING, + IS_OPENED, +}; + +static const char *CLOSED = "closed"; +static const char *CLOSING = "closing"; +static const char *ERROR = "error"; +static const char *OFFLINE = "offline"; +static const char *ONLINE = "online"; +static const char *OPENING = "opening"; +static const char *SUSPENDED = "suspended"; +static const char *UNKNOWN = "unknown"; + +/* Version 2 uses the kernel space UDS index and is limited to 16 bytes */ +enum { + UDS_ADVICE_VERSION = 2, + /* version byte + state byte + 64-bit little-endian PBN */ + UDS_ADVICE_SIZE = 1 + 1 + sizeof(u64), +}; + enum hash_lock_state { /* State for locks that are not in use or are being initialized. */ VDO_HASH_LOCK_INITIALIZING, @@ -264,6 +306,13 @@ struct hash_zones { struct hash_zone zones[]; }; +/* These are in milliseconds. */ +unsigned int vdo_dedupe_index_timeout_interval = 5000; +unsigned int vdo_dedupe_index_min_timer_interval = 100; +/* Same two variables, in jiffies for easier consumption. */ +static u64 vdo_dedupe_index_timeout_jiffies; +static u64 vdo_dedupe_index_min_timer_jiffies; + static inline struct hash_zone *as_hash_zone(struct vdo_completion *completion) { vdo_assert_completion_type(completion, VDO_HASH_ZONE_COMPLETION); @@ -283,6 +332,16 @@ static inline void assert_in_hash_zone(struct hash_zone *zone, const char *name) name); } +static inline bool change_context_state(struct dedupe_context *context, int old, int new) +{ + return (atomic_cmpxchg(&context->state, old, new) == old); +} + +static inline bool change_timer_state(struct hash_zone *zone, int old, int new) +{ + return (atomic_cmpxchg(&zone->timer_state, old, new) == old); +} + /** * return_hash_lock_to_pool() - (Re)initialize a hash lock and return it to its pool. * @zone: The zone from which the lock was borrowed. @@ -1955,6 +2014,376 @@ static u32 hash_key(const void *key) return get_unaligned_le32(&name->name[4]); } +static void dedupe_kobj_release(struct kobject *directory) +{ + UDS_FREE(container_of(directory, struct hash_zones, dedupe_directory)); +} + +static ssize_t dedupe_status_show(struct kobject *directory, struct attribute *attr, char *buf) +{ + struct uds_attribute *ua = container_of(attr, struct uds_attribute, attr); + struct hash_zones *zones = container_of(directory, struct hash_zones, dedupe_directory); + + if (ua->show_string != NULL) + return sprintf(buf, "%s\n", ua->show_string(zones)); + else + return -EINVAL; +} + +static ssize_t dedupe_status_store(struct kobject *kobj __always_unused, + struct attribute *attr __always_unused, + const char *buf __always_unused, + size_t length __always_unused) +{ + return -EINVAL; +} + +/*----------------------------------------------------------------------*/ + +static const struct sysfs_ops dedupe_sysfs_ops = { + .show = dedupe_status_show, + .store = dedupe_status_store, +}; + +static struct uds_attribute dedupe_status_attribute = { + .attr = {.name = "status", .mode = 0444, }, + .show_string = vdo_get_dedupe_index_state_name, +}; + +static struct attribute *dedupe_attrs[] = { + &dedupe_status_attribute.attr, + NULL, +}; +ATTRIBUTE_GROUPS(dedupe); + +static struct kobj_type dedupe_directory_type = { + .release = dedupe_kobj_release, + .sysfs_ops = &dedupe_sysfs_ops, + .default_groups = dedupe_groups, +}; + +static void start_uds_queue(void *ptr) +{ + /* + * Allow the UDS dedupe worker thread to do memory allocations. It will only do allocations + * during the UDS calls that open or close an index, but those allocations can safely sleep + * while reserving a large amount of memory. We could use an allocations_allowed boolean + * (like the base threads do), but it would be an unnecessary embellishment. + */ + struct vdo_thread *thread = vdo_get_work_queue_owner(vdo_get_current_work_queue()); + + uds_register_allocating_thread(&thread->allocating_thread, NULL); +} + +static void finish_uds_queue(void *ptr __always_unused) +{ + uds_unregister_allocating_thread(); +} + +static void close_index(struct hash_zones *zones) +{ + int result; + + /* + * Change the index state so that get_index_statistics() will not try to use the index + * session we are closing. + */ + zones->index_state = IS_CHANGING; + /* Close the index session, while not holding the lock. */ + spin_unlock(&zones->lock); + result = uds_close_index(zones->index_session); + + if (result != UDS_SUCCESS) + uds_log_error_strerror(result, "Error closing index"); + spin_lock(&zones->lock); + zones->index_state = IS_CLOSED; + zones->error_flag |= result != UDS_SUCCESS; + /* ASSERTION: We leave in IS_CLOSED state. */ +} + +static void open_index(struct hash_zones *zones) +{ + /* ASSERTION: We enter in IS_CLOSED state. */ + int result; + bool create_flag = zones->create_flag; + + zones->create_flag = false; + /* + * Change the index state so that the it will be reported to the outside world as + * "opening". + */ + zones->index_state = IS_CHANGING; + zones->error_flag = false; + + /* Open the index session, while not holding the lock */ + spin_unlock(&zones->lock); + result = uds_open_index(create_flag ? UDS_CREATE : UDS_LOAD, + &zones->parameters, + zones->index_session); + if (result != UDS_SUCCESS) + uds_log_error_strerror(result, "Error opening index"); + + spin_lock(&zones->lock); + if (!create_flag) { + switch (result) { + case -ENOENT: + /* + * Either there is no index, or there is no way we can recover the index. + * We will be called again and try to create a new index. + */ + zones->index_state = IS_CLOSED; + zones->create_flag = true; + return; + default: + break; + } + } + if (result == UDS_SUCCESS) { + zones->index_state = IS_OPENED; + } else { + zones->index_state = IS_CLOSED; + zones->index_target = IS_CLOSED; + zones->error_flag = true; + spin_unlock(&zones->lock); + uds_log_info("Setting UDS index target state to error"); + spin_lock(&zones->lock); + } + /* + * ASSERTION: On success, we leave in IS_OPENED state. + * ASSERTION: On failure, we leave in IS_CLOSED state. + */ +} + +static void change_dedupe_state(struct vdo_completion *completion) +{ + struct hash_zones *zones = as_hash_zones(completion); + + spin_lock(&zones->lock); + + /* Loop until the index is in the target state and the create flag is clear. */ + while (vdo_is_state_normal(&zones->state) && + ((zones->index_state != zones->index_target) || zones->create_flag)) { + if (zones->index_state == IS_OPENED) + close_index(zones); + else + open_index(zones); + } + + zones->changing = false; + spin_unlock(&zones->lock); +} + +static void start_expiration_timer(struct dedupe_context *context) +{ + u64 start_time = context->submission_jiffies; + u64 end_time; + + if (!change_timer_state(context->zone, + DEDUPE_QUERY_TIMER_IDLE, + DEDUPE_QUERY_TIMER_RUNNING)) + return; + + end_time = max(start_time + vdo_dedupe_index_timeout_jiffies, + jiffies + vdo_dedupe_index_min_timer_jiffies); + mod_timer(&context->zone->timer, end_time); +} + +/** + * report_dedupe_timeouts() - Record and eventually report that some dedupe requests reached their + * expiration time without getting answers, so we timed them out. + * @zones: the hash zones. + * @timeouts: the number of newly timed out requests. + */ +static void report_dedupe_timeouts(struct hash_zones *zones, unsigned int timeouts) +{ + atomic64_add(timeouts, &zones->timeouts); + spin_lock(&zones->lock); + if (__ratelimit(&zones->ratelimiter)) { + u64 unreported = atomic64_read(&zones->timeouts); + + unreported -= zones->reported_timeouts; + uds_log_debug("UDS index timeout on %llu requests", + (unsigned long long) unreported); + zones->reported_timeouts += unreported; + } + spin_unlock(&zones->lock); +} + +static int initialize_index(struct vdo *vdo, struct hash_zones *zones) +{ + int result; + off_t uds_offset; + struct volume_geometry geometry = vdo->geometry; + static const struct vdo_work_queue_type uds_queue_type = { + .start = start_uds_queue, + .finish = finish_uds_queue, + .max_priority = UDS_Q_MAX_PRIORITY, + .default_priority = UDS_Q_PRIORITY, + }; + + vdo_set_dedupe_index_timeout_interval(vdo_dedupe_index_timeout_interval); + vdo_set_dedupe_index_min_timer_interval(vdo_dedupe_index_min_timer_interval); + + /* + * Since we will save up the timeouts that would have been reported but were ratelimited, + * we don't need to report ratelimiting. + */ + ratelimit_default_init(&zones->ratelimiter); + ratelimit_set_flags(&zones->ratelimiter, RATELIMIT_MSG_ON_RELEASE); + uds_offset = ((vdo_get_index_region_start(geometry) - + geometry.bio_offset) * VDO_BLOCK_SIZE); + zones->parameters = (struct uds_parameters) { + .name = vdo->device_config->parent_device_name, + .offset = uds_offset, + .size = (vdo_get_index_region_size(geometry) * VDO_BLOCK_SIZE), + .memory_size = geometry.index_config.mem, + .sparse = geometry.index_config.sparse, + .nonce = (u64) geometry.nonce, + }; + + result = uds_create_index_session(&zones->index_session); + if (result != UDS_SUCCESS) + return result; + + result = vdo_make_thread(vdo, vdo->thread_config.dedupe_thread, &uds_queue_type, 1, NULL); + if (result != VDO_SUCCESS) { + uds_destroy_index_session(UDS_FORGET(zones->index_session)); + uds_log_error("UDS index queue initialization failed (%d)", result); + return result; + } + + vdo_initialize_completion(&zones->completion, vdo, VDO_HASH_ZONES_COMPLETION); + vdo_set_completion_callback(&zones->completion, + change_dedupe_state, + vdo->thread_config.dedupe_thread); + kobject_init(&zones->dedupe_directory, &dedupe_directory_type); + return VDO_SUCCESS; +} + +/** + * finish_index_operation() - This is the UDS callback for index queries. + * @request: The uds request which has just completed. + */ +static void finish_index_operation(struct uds_request *request) +{ + struct dedupe_context *context = container_of(request, struct dedupe_context, request); + + if (change_context_state(context, DEDUPE_CONTEXT_PENDING, DEDUPE_CONTEXT_COMPLETE)) { + /* + * This query has not timed out, so send its data_vio back to its hash zone to + * process the results. + */ + continue_data_vio(context->requestor); + return; + } + + /* + * This query has timed out, so try to mark it complete and hence eligible for reuse. Its + * data_vio has already moved on. + */ + if (!change_context_state(context, + DEDUPE_CONTEXT_TIMED_OUT, + DEDUPE_CONTEXT_TIMED_OUT_COMPLETE)) + ASSERT_LOG_ONLY(false, + "uds request was timed out (state %d)", + atomic_read(&context->state)); + + uds_funnel_queue_put(context->zone->timed_out_complete, &context->queue_entry); +} + +/** + * check_for_drain_complete() - Check whether this zone has drained. + * @zone: The zone to check. + */ +static void check_for_drain_complete(struct hash_zone *zone) +{ + data_vio_count_t recycled = 0; + + if (!vdo_is_state_draining(&zone->state)) + return; + + if ((atomic_read(&zone->timer_state) == DEDUPE_QUERY_TIMER_IDLE) || + change_timer_state(zone, DEDUPE_QUERY_TIMER_RUNNING, DEDUPE_QUERY_TIMER_IDLE)) + del_timer_sync(&zone->timer); + else + /* + * There is an in flight time-out, which must get processed before we can continue. + */ + return; + + for (;;) { + struct dedupe_context *context; + struct funnel_queue_entry *entry; + + entry = uds_funnel_queue_poll(zone->timed_out_complete); + if (entry == NULL) + break; + + context = container_of(entry, struct dedupe_context, queue_entry); + atomic_set(&context->state, DEDUPE_CONTEXT_IDLE); + list_add(&context->list_entry, &zone->available); + recycled++; + } + + if (recycled > 0) + WRITE_ONCE(zone->active, zone->active - recycled); + ASSERT_LOG_ONLY(READ_ONCE(zone->active) == 0, "all contexts inactive"); + vdo_finish_draining(&zone->state); +} + +static void timeout_index_operations_callback(struct vdo_completion *completion) +{ + struct dedupe_context *context, *tmp; + struct hash_zone *zone = as_hash_zone(completion); + u64 timeout_jiffies = msecs_to_jiffies(vdo_dedupe_index_timeout_interval); + unsigned long cutoff = jiffies - timeout_jiffies; + unsigned int timed_out = 0; + + atomic_set(&zone->timer_state, DEDUPE_QUERY_TIMER_IDLE); + list_for_each_entry_safe(context, tmp, &zone->pending, list_entry) { + if (cutoff <= context->submission_jiffies) { + /* + * We have reached the oldest query which has not timed out yet, so restart + * the timer. + */ + start_expiration_timer(context); + break; + } + + if (!change_context_state(context, + DEDUPE_CONTEXT_PENDING, + DEDUPE_CONTEXT_TIMED_OUT)) + /* + * This context completed between the time the timeout fired, and now. We + * can treat it as a a successful query, its requestor is already enqueued + * to process it. + */ + continue; + + /* + * Remove this context from the pending list so we won't look at it again on a + * subsequent timeout. Once the index completes it, it will be reused. Meanwhile, + * send its requestor on its way. + */ + list_del_init(&context->list_entry); + continue_data_vio(context->requestor); + timed_out++; + } + + if (timed_out > 0) + report_dedupe_timeouts(completion->vdo->hash_zones, timed_out); + + check_for_drain_complete(zone); +} + +static void timeout_index_operations(struct timer_list *t) +{ + struct hash_zone *zone = from_timer(zone, t, timer); + + if (change_timer_state(zone, DEDUPE_QUERY_TIMER_RUNNING, DEDUPE_QUERY_TIMER_FIRED)) + vdo_launch_completion(&zone->completion); +} + static int __must_check initialize_zone(struct vdo *vdo, struct hash_zones *zones, zone_count_t zone_number) { @@ -2449,3 +2878,196 @@ void vdo_dump_hash_zones(struct hash_zones *zones) dump_hash_zone(&zones->zones[zone]); } +void vdo_set_dedupe_index_timeout_interval(unsigned int value) +{ + u64 alb_jiffies; + + /* Arbitrary maximum value is two minutes */ + if (value > 120000) + value = 120000; + /* Arbitrary minimum value is 2 jiffies */ + alb_jiffies = msecs_to_jiffies(value); + + if (alb_jiffies < 2) { + alb_jiffies = 2; + value = jiffies_to_msecs(alb_jiffies); + } + vdo_dedupe_index_timeout_interval = value; + vdo_dedupe_index_timeout_jiffies = alb_jiffies; +} + +void vdo_set_dedupe_index_min_timer_interval(unsigned int value) +{ + u64 min_jiffies; + + /* Arbitrary maximum value is one second */ + if (value > 1000) + value = 1000; + + /* Arbitrary minimum value is 2 jiffies */ + min_jiffies = msecs_to_jiffies(value); + + if (min_jiffies < 2) { + min_jiffies = 2; + value = jiffies_to_msecs(min_jiffies); + } + + vdo_dedupe_index_min_timer_interval = value; + vdo_dedupe_index_min_timer_jiffies = min_jiffies; +} + +/** + * acquire_context() - Acquire a dedupe context from a hash_zone if any are available. + * @zone: the hash zone + * + * Return: A dedupe_context or NULL if none are available + */ +static struct dedupe_context * __must_check acquire_context(struct hash_zone *zone) +{ + struct dedupe_context *context; + struct funnel_queue_entry *entry; + + assert_in_hash_zone(zone, __func__); + + if (!list_empty(&zone->available)) { + WRITE_ONCE(zone->active, zone->active + 1); + context = list_first_entry(&zone->available, struct dedupe_context, list_entry); + list_del_init(&context->list_entry); + return context; + } + + entry = uds_funnel_queue_poll(zone->timed_out_complete); + return ((entry == NULL) ? NULL : container_of(entry, struct dedupe_context, queue_entry)); +} + +static void prepare_uds_request(struct uds_request *request, + struct data_vio *data_vio, + enum uds_request_type operation) +{ + request->record_name = data_vio->record_name; + request->type = operation; + if ((operation == UDS_POST) || (operation == UDS_UPDATE)) { + size_t offset = 0; + struct uds_record_data *encoding = &request->new_metadata; + + encoding->data[offset++] = UDS_ADVICE_VERSION; + encoding->data[offset++] = data_vio->new_mapped.state; + put_unaligned_le64(data_vio->new_mapped.pbn, &encoding->data[offset]); + offset += sizeof(u64); + BUG_ON(offset != UDS_ADVICE_SIZE); + } +} + +/* + * The index operation will inquire about data_vio.record_name, providing (if the operation is + * appropriate) advice from the data_vio's new_mapped fields. The advice found in the index (or + * NULL if none) will be returned via receive_data_vio_dedupe_advice(). dedupe_context.status is + * set to the return status code of any asynchronous index processing. + */ +static void query_index(struct data_vio *data_vio, enum uds_request_type operation) +{ + int result; + struct dedupe_context *context; + struct vdo *vdo = vdo_from_data_vio(data_vio); + struct hash_zone *zone = data_vio->hash_zone; + + assert_data_vio_in_hash_zone(data_vio); + + if (!READ_ONCE(vdo->hash_zones->dedupe_flag)) { + continue_data_vio(data_vio); + return; + } + + context = acquire_context(zone); + if (context == NULL) { + atomic64_inc(&vdo->hash_zones->dedupe_context_busy); + continue_data_vio(data_vio); + return; + } + + data_vio->dedupe_context = context; + context->requestor = data_vio; + context->submission_jiffies = jiffies; + prepare_uds_request(&context->request, data_vio, operation); + atomic_set(&context->state, DEDUPE_CONTEXT_PENDING); + list_add_tail(&context->list_entry, &zone->pending); + start_expiration_timer(context); + result = uds_launch_request(&context->request); + if (result != UDS_SUCCESS) { + context->request.status = result; + finish_index_operation(&context->request); + } +} + +static void set_target_state(struct hash_zones *zones, + enum index_state target, + bool change_dedupe, + bool dedupe, + bool set_create) +{ + const char *old_state, *new_state; + + spin_lock(&zones->lock); + old_state = index_state_to_string(zones, zones->index_target); + if (change_dedupe) + WRITE_ONCE(zones->dedupe_flag, dedupe); + + if (set_create) + zones->create_flag = true; + + zones->index_target = target; + launch_dedupe_state_change(zones); + new_state = index_state_to_string(zones, zones->index_target); + spin_unlock(&zones->lock); + + if (old_state != new_state) + uds_log_info("Setting UDS index target state to %s", new_state); +} + +const char *vdo_get_dedupe_index_state_name(struct hash_zones *zones) +{ + const char *state; + + spin_lock(&zones->lock); + state = index_state_to_string(zones, zones->index_state); + spin_unlock(&zones->lock); + + return state; +} + +/* Handle a dmsetup message relevant to the index. */ +int vdo_message_dedupe_index(struct hash_zones *zones, const char *name) +{ + if (strcasecmp(name, "index-close") == 0) { + set_target_state(zones, IS_CLOSED, false, false, false); + return 0; + } else if (strcasecmp(name, "index-create") == 0) { + set_target_state(zones, IS_OPENED, false, false, true); + return 0; + } else if (strcasecmp(name, "index-disable") == 0) { + set_target_state(zones, IS_OPENED, true, false, false); + return 0; + } else if (strcasecmp(name, "index-enable") == 0) { + set_target_state(zones, IS_OPENED, true, true, false); + return 0; + } + return -EINVAL; +} + +int vdo_add_dedupe_index_sysfs(struct hash_zones *zones) +{ + int result = kobject_add(&zones->dedupe_directory, + &zones->completion.vdo->vdo_directory, + "dedupe"); + + if (result == 0) + vdo_set_admin_state_code(&zones->state, VDO_ADMIN_STATE_NORMAL_OPERATION); + + return result; +} + +/* If create_flag, create a new index without first attempting to load an existing index. */ +void vdo_start_dedupe_index(struct hash_zones *zones, bool create_flag) +{ + set_target_state(zones, IS_OPENED, true, true, create_flag); +} diff --git a/drivers/md/dm-vdo/dedupe.h b/drivers/md/dm-vdo/dedupe.h index e119d74c6f0..60ff7b5dc9f 100644 --- a/drivers/md/dm-vdo/dedupe.h +++ b/drivers/md/dm-vdo/dedupe.h @@ -90,4 +90,30 @@ vdo_select_hash_zone(struct hash_zones *zones, const struct uds_record_name *nam void vdo_dump_hash_zones(struct hash_zones *zones); +const char *vdo_get_dedupe_index_state_name(struct hash_zones *zones); + +u64 vdo_get_dedupe_index_timeout_count(struct hash_zones *zones); + +int vdo_message_dedupe_index(struct hash_zones *zones, const char *name); + +int vdo_add_dedupe_index_sysfs(struct hash_zones *zones); + +void vdo_start_dedupe_index(struct hash_zones *zones, bool create_flag); + +void vdo_resume_hash_zones(struct hash_zones *zones, struct vdo_completion *parent); + +void vdo_finish_dedupe_index(struct hash_zones *zones); + +/* Interval (in milliseconds) from submission until switching to fast path and skipping UDS. */ +extern unsigned int vdo_dedupe_index_timeout_interval; + +/* + * Minimum time interval (in milliseconds) between timer invocations to check for requests waiting + * for UDS that should now time out. + */ +extern unsigned int vdo_dedupe_index_min_timer_interval; + +void vdo_set_dedupe_index_timeout_interval(unsigned int value); +void vdo_set_dedupe_index_min_timer_interval(unsigned int value); + #endif /* VDO_DEDUPE_H */ -- 2.40.1 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel