// 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 <linux/completion.h>
#include <linux/device-mapper.h>
#include <linux/kernel.h>
#include <linux/lz4.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#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 "funnel-workqueue.h"
#include "io-submitter.h"
#include "logical-zone.h"
#include "packer.h"
#include "physical-zone.h"
#include "recovery-journal.h"
#include "slab-depot.h"
#include "statistics.h"
#include "status-codes.h"
#include "vio.h"
#define PARANOID_THREAD_CONSISTENCY_CHECKS 0
struct sync_completion {
struct vdo_completion vdo_completion;
struct completion completion;
};
/* A linked list is adequate for the small number of entries we expect. */
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_fn. */
static bool vdo_is_equal(struct vdo *vdo, const void *context)
{
return (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_fn 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_fn 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());
vdo_register_allocating_thread(&thread->allocating_thread,
&thread->vdo->allocations_allowed);
}
static void finish_vdo_request_queue(void *ptr)
{
vdo_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)
{
vdo_free(vdo_forget(config->logical_threads));
vdo_free(vdo_forget(config->physical_threads));
vdo_free(vdo_forget(config->hash_zone_threads));
vdo_free(vdo_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 = vdo_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 = vdo_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 = vdo_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 = vdo_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;
}
/**
* 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 = vdo_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) {
vdo_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(vdo_forget(vio));
vdo_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(vdo_forget(vio));
if (result != 0) {
vdo_log_error_strerror(result, "synchronous read failed");
vdo_free(block);
return -EIO;
}
result = vdo_parse_geometry_block((u8 *) block, &vdo->geometry);
vdo_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 VDO_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 = VDO_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;
}
vdo_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 = vdo_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 = vdo_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;
/* Initialize with a generic failure reason to prevent returning garbage. */
*reason = "Unspecified error";
result = vdo_allocate(1, struct vdo, __func__, &vdo);
if (result != VDO_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 = vdo_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 = vdo_forget(thread->listeners); listener != NULL; listener = next) {
next = vdo_forget(listener->next);
vdo_free(listener);
}
}
static void uninitialize_super_block(struct vdo_super_block *super_block)
{
free_vio_components(&super_block->vio);
vdo_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;
finish_vdo(vdo);
unregister_vdo(vdo);
free_data_vio_pool(vdo->data_vio_pool);
vdo_free_io_submitter(vdo_forget(vdo->io_submitter));
vdo_free_flusher(vdo_forget(vdo->flusher));
vdo_free_packer(vdo_forget(vdo->packer));
vdo_free_recovery_journal(vdo_forget(vdo->recovery_journal));
vdo_free_slab_depot(vdo_forget(vdo->depot));
vdo_uninitialize_layout(&vdo->layout);
vdo_uninitialize_layout(&vdo->next_layout);
if (vdo->partition_copier)
dm_kcopyd_client_destroy(vdo_forget(vdo->partition_copier));
uninitialize_super_block(&vdo->super_block);
vdo_free_block_map(vdo_forget(vdo->block_map));
vdo_free_hash_zones(vdo_forget(vdo->hash_zones));
vdo_free_physical_zones(vdo_forget(vdo->physical_zones));
vdo_free_logical_zones(vdo_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(vdo_forget(vdo->threads[i].queue));
}
vdo_free(vdo_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++)
vdo_free(vdo_forget(vdo->compression_context[i]));
vdo_free(vdo_forget(vdo->compression_context));
}
vdo_free(vdo);
}
static int initialize_super_block(struct vdo *vdo, struct vdo_super_block *super_block)
{
int result;
result = vdo_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(vdo_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;
vdo_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);
}
/**
* 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), NULL, 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) {
vdo_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(vdo_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);
vdo_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;
vdo_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_fn notification,
thread_id_t thread_id)
{
struct vdo_thread *thread = &vdo->threads[thread_id];
struct read_only_listener *read_only_listener;
int result;
result = VDO_ASSERT(thread_id != vdo->thread_config.dedupe_thread,
"read only listener not registered on dedupe thread");
if (result != VDO_SUCCESS)
return result;
result = vdo_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_fn.
*/
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(vdo_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)
vdo_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;
vdo_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_fn 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);
}
}
vdo_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);
vdo_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)
{
VDO_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)
{
VDO_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)
{
VDO_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 = VDO_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;
}
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