86 lines
1.9 KiB
C
86 lines
1.9 KiB
C
/*
|
|
* Copyright (C) 2003 Sistina Software
|
|
* Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
|
|
*
|
|
* Device-Mapper low-level I/O.
|
|
*
|
|
* This file is released under the GPL.
|
|
*/
|
|
|
|
#ifndef _LINUX_DM_IO_H
|
|
#define _LINUX_DM_IO_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/types.h>
|
|
|
|
struct dm_io_region {
|
|
struct block_device *bdev;
|
|
sector_t sector;
|
|
sector_t count; /* If this is zero the region is ignored. */
|
|
};
|
|
|
|
struct page_list {
|
|
struct page_list *next;
|
|
struct page *page;
|
|
};
|
|
|
|
typedef void (*io_notify_fn)(unsigned long error, void *context);
|
|
|
|
enum dm_io_mem_type {
|
|
DM_IO_PAGE_LIST,/* Page list */
|
|
DM_IO_BIO, /* Bio vector */
|
|
DM_IO_VMA, /* Virtual memory area */
|
|
DM_IO_KMEM, /* Kernel memory */
|
|
};
|
|
|
|
struct dm_io_memory {
|
|
enum dm_io_mem_type type;
|
|
|
|
unsigned offset;
|
|
|
|
union {
|
|
struct page_list *pl;
|
|
struct bio *bio;
|
|
void *vma;
|
|
void *addr;
|
|
} ptr;
|
|
};
|
|
|
|
struct dm_io_notify {
|
|
io_notify_fn fn; /* Callback for asynchronous requests */
|
|
void *context; /* Passed to callback */
|
|
};
|
|
|
|
/*
|
|
* IO request structure
|
|
*/
|
|
struct dm_io_client;
|
|
struct dm_io_request {
|
|
int bi_op; /* REQ_OP */
|
|
int bi_op_flags; /* req_flag_bits */
|
|
struct dm_io_memory mem; /* Memory to use for io */
|
|
struct dm_io_notify notify; /* Synchronous if notify.fn is NULL */
|
|
struct dm_io_client *client; /* Client memory handler */
|
|
};
|
|
|
|
/*
|
|
* For async io calls, users can alternatively use the dm_io() function below
|
|
* and dm_io_client_create() to create private mempools for the client.
|
|
*
|
|
* Create/destroy may block.
|
|
*/
|
|
struct dm_io_client *dm_io_client_create(void);
|
|
void dm_io_client_destroy(struct dm_io_client *client);
|
|
|
|
/*
|
|
* IO interface using private per-client pools.
|
|
* Each bit in the optional 'sync_error_bits' bitset indicates whether an
|
|
* error occurred doing io to the corresponding region.
|
|
*/
|
|
int dm_io(struct dm_io_request *io_req, unsigned num_regions,
|
|
struct dm_io_region *region, unsigned long *sync_error_bits);
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _LINUX_DM_IO_H */
|