Release 4.12 include/linux/dm-io.h

/*
 * 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 */
Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Heinz Mauelshagen
138
66.67%
2
22.22%
Alasdair G. Kergon
54
26.09%
1
11.11%
Michael Christie
5
2.42%
1
11.11%
Kent Overstreet
3
1.45%
1
11.11%
Mike Snitzer
3
1.45%
1
11.11%
Milan Broz
2
0.97%
1
11.11%
Mikulas Patocka
1
0.48%
1
11.11%
Christoph Hellwig
1
0.48%
1
11.11%
Total
207
100.00%
9
100.00%
Directory: include/linux

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.