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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172/* SPDX-License-Identifier: GPL-2.0-only *//* * Copyright (C) 2009-2011 Red Hat, Inc. * * Author: Mikulas Patocka <mpatocka@redhat.com> * * This file is released under the GPL. */
#ifndef _LINUX_DM_BUFIO_H#define _LINUX_DM_BUFIO_H
#include <linux/blkdev.h>#include <linux/types.h>
/*----------------------------------------------------------------*/
struct dm_bufio_client;struct dm_buffer;
/* * Flags for dm_bufio_client_create */#define DM_BUFIO_CLIENT_NO_SLEEP 0x1
/* * Create a buffered IO cache on a given device */struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsigned int block_size, unsigned int reserved_buffers, unsigned int aux_size, void (*alloc_callback)(struct dm_buffer *), void (*write_callback)(struct dm_buffer *), unsigned int flags);
/* * Release a buffered IO cache. */void dm_bufio_client_destroy(struct dm_bufio_client *c);
void dm_bufio_client_reset(struct dm_bufio_client *c);
/* * Set the sector range. * When this function is called, there must be no I/O in progress on the bufio * client. */void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start);
/* * WARNING: to avoid deadlocks, these conditions are observed: * * - At most one thread can hold at most "reserved_buffers" simultaneously. * - Each other threads can hold at most one buffer. * - Threads which call only dm_bufio_get can hold unlimited number of * buffers. */
/* * Read a given block from disk. Returns pointer to data. Returns a * pointer to dm_buffer that can be used to release the buffer or to make * it dirty. */void *dm_bufio_read(struct dm_bufio_client *c, sector_t block, struct dm_buffer **bp);
void *dm_bufio_read_with_ioprio(struct dm_bufio_client *c, sector_t block, struct dm_buffer **bp, unsigned short ioprio);
/* * Like dm_bufio_read, but return buffer from cache, don't read * it. If the buffer is not in the cache, return NULL. */void *dm_bufio_get(struct dm_bufio_client *c, sector_t block, struct dm_buffer **bp);
/* * Like dm_bufio_read, but don't read anything from the disk. It is * expected that the caller initializes the buffer and marks it dirty. */void *dm_bufio_new(struct dm_bufio_client *c, sector_t block, struct dm_buffer **bp);
/* * Prefetch the specified blocks to the cache. * The function starts to read the blocks and returns without waiting for * I/O to finish. */void dm_bufio_prefetch(struct dm_bufio_client *c, sector_t block, unsigned int n_blocks);
void dm_bufio_prefetch_with_ioprio(struct dm_bufio_client *c, sector_t block, unsigned int n_blocks, unsigned short ioprio);
/* * Release a reference obtained with dm_bufio_{read,get,new}. The data * pointer and dm_buffer pointer is no longer valid after this call. */void dm_bufio_release(struct dm_buffer *b);
/* * Mark a buffer dirty. It should be called after the buffer is modified. * * In case of memory pressure, the buffer may be written after * dm_bufio_mark_buffer_dirty, but before dm_bufio_write_dirty_buffers. So * dm_bufio_write_dirty_buffers guarantees that the buffer is on-disk but * the actual writing may occur earlier. */void dm_bufio_mark_buffer_dirty(struct dm_buffer *b);
/* * Mark a part of the buffer dirty. * * The specified part of the buffer is scheduled to be written. dm-bufio may * write the specified part of the buffer or it may write a larger superset. */void dm_bufio_mark_partial_buffer_dirty(struct dm_buffer *b, unsigned int start, unsigned int end);
/* * Initiate writing of dirty buffers, without waiting for completion. */void dm_bufio_write_dirty_buffers_async(struct dm_bufio_client *c);
/* * Write all dirty buffers. Guarantees that all dirty buffers created prior * to this call are on disk when this call exits. */int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c);
/* * Send an empty write barrier to the device to flush hardware disk cache. */int dm_bufio_issue_flush(struct dm_bufio_client *c);
/* * Send a discard request to the underlying device. */int dm_bufio_issue_discard(struct dm_bufio_client *c, sector_t block, sector_t count);
/* * Free the given buffer. * This is just a hint, if the buffer is in use or dirty, this function * does nothing. */void dm_bufio_forget(struct dm_bufio_client *c, sector_t block);
/* * Free the given range of buffers. * This is just a hint, if the buffer is in use or dirty, this function * does nothing. */void dm_bufio_forget_buffers(struct dm_bufio_client *c, sector_t block, sector_t n_blocks);
/* * Set the minimum number of buffers before cleanup happens. */void dm_bufio_set_minimum_buffers(struct dm_bufio_client *c, unsigned int n);
unsigned int dm_bufio_get_block_size(struct dm_bufio_client *c);sector_t dm_bufio_get_device_size(struct dm_bufio_client *c);struct dm_io_client *dm_bufio_get_dm_io_client(struct dm_bufio_client *c);sector_t dm_bufio_get_block_number(struct dm_buffer *b);void *dm_bufio_get_block_data(struct dm_buffer *b);void *dm_bufio_get_aux_data(struct dm_buffer *b);struct dm_bufio_client *dm_bufio_get_client(struct dm_buffer *b);
/*----------------------------------------------------------------*/
#endif