linux/drivers/md/dm-vdo/vio.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2023 Red Hat
 */

#include "vio.h"

#include <linux/bio.h>
#include <linux/blkdev.h>
#include <linux/kernel.h>
#include <linux/ratelimit.h>

#include "logger.h"
#include "memory-alloc.h"
#include "permassert.h"

#include "constants.h"
#include "io-submitter.h"
#include "vdo.h"

/* A vio_pool is a collection of preallocated vios. */
struct vio_pool { … };

physical_block_number_t pbn_from_vio_bio(struct bio *bio)
{ … }

static int create_multi_block_bio(block_count_t size, struct bio **bio_ptr)
{ … }

int vdo_create_bio(struct bio **bio_ptr)
{ … }

void vdo_free_bio(struct bio *bio)
{ … }

int allocate_vio_components(struct vdo *vdo, enum vio_type vio_type,
			    enum vio_priority priority, void *parent,
			    unsigned int block_count, char *data, struct vio *vio)
{ … }

/**
 * create_multi_block_metadata_vio() - Create a vio.
 * @vdo: The vdo on which the vio will operate.
 * @vio_type: The type of vio to create.
 * @priority: The relative priority to assign to the vio.
 * @parent: The parent of the vio.
 * @block_count: The size of the vio in blocks.
 * @data: The buffer.
 * @vio_ptr: A pointer to hold the new vio.
 *
 * Return: VDO_SUCCESS or an error.
 */
int create_multi_block_metadata_vio(struct vdo *vdo, enum vio_type vio_type,
				    enum vio_priority priority, void *parent,
				    unsigned int block_count, char *data,
				    struct vio **vio_ptr)
{ … }

/**
 * free_vio_components() - Free the components of a vio embedded in a larger structure.
 * @vio: The vio to destroy
 */
void free_vio_components(struct vio *vio)
{ … }

/**
 * free_vio() - Destroy a vio.
 * @vio: The vio to destroy.
 */
void free_vio(struct vio *vio)
{ … }

/* Set bio properties for a VDO read or write. */
void vdo_set_bio_properties(struct bio *bio, struct vio *vio, bio_end_io_t callback,
			    blk_opf_t bi_opf, physical_block_number_t pbn)
{ … }

/*
 * Prepares the bio to perform IO with the specified buffer. May only be used on a VDO-allocated
 * bio, as it assumes the bio wraps a 4k buffer that is 4k aligned, but there does not have to be a
 * vio associated with the bio.
 */
int vio_reset_bio(struct vio *vio, char *data, bio_end_io_t callback,
		  blk_opf_t bi_opf, physical_block_number_t pbn)
{ … }

/**
 * update_vio_error_stats() - Update per-vio error stats and log the error.
 * @vio: The vio which got an error.
 * @format: The format of the message to log (a printf style format).
 */
void update_vio_error_stats(struct vio *vio, const char *format, ...)
{ … }

void vio_record_metadata_io_error(struct vio *vio)
{ … }

/**
 * make_vio_pool() - Create a new vio pool.
 * @vdo: The vdo.
 * @pool_size: The number of vios in the pool.
 * @thread_id: The ID of the thread using this pool.
 * @vio_type: The type of vios in the pool.
 * @priority: The priority with which vios from the pool should be enqueued.
 * @context: The context that each entry will have.
 * @pool_ptr: The resulting pool.
 *
 * Return: A success or error code.
 */
int make_vio_pool(struct vdo *vdo, size_t pool_size, thread_id_t thread_id,
		  enum vio_type vio_type, enum vio_priority priority, void *context,
		  struct vio_pool **pool_ptr)
{ … }

/**
 * free_vio_pool() - Destroy a vio pool.
 * @pool: The pool to free.
 */
void free_vio_pool(struct vio_pool *pool)
{ … }

/**
 * is_vio_pool_busy() - Check whether an vio pool has outstanding entries.
 *
 * Return: true if the pool is busy.
 */
bool is_vio_pool_busy(struct vio_pool *pool)
{ … }

/**
 * acquire_vio_from_pool() - Acquire a vio and buffer from the pool (asynchronous).
 * @pool: The vio pool.
 * @waiter: Object that is requesting a vio.
 */
void acquire_vio_from_pool(struct vio_pool *pool, struct vdo_waiter *waiter)
{ … }

/**
 * return_vio_to_pool() - Return a vio to the pool
 * @pool: The vio pool.
 * @vio: The pooled vio to return.
 */
void return_vio_to_pool(struct vio_pool *pool, struct pooled_vio *vio)
{ … }

/*
 * Various counting functions for statistics.
 * These are used for bios coming into VDO, as well as bios generated by VDO.
 */
void vdo_count_bios(struct atomic_bio_stats *bio_stats, struct bio *bio)
{ … }

static void count_all_bios_completed(struct vio *vio, struct bio *bio)
{ … }

void vdo_count_completed_bios(struct bio *bio)
{ … }