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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _LVM_DEVICE_H
#define _LVM_DEVICE_H
#include "uuid.h"
#include <fcntl.h>
#include <libaio.h>
#define DEV_ACCESSED_W 0x00000001 /* Device written to? */
#define DEV_REGULAR 0x00000002 /* Regular file? */
#define DEV_ALLOCED 0x00000004 /* dm_malloc used */
#define DEV_OPENED_RW 0x00000008 /* Opened RW */
#define DEV_OPENED_EXCL 0x00000010 /* Opened EXCL */
#define DEV_O_DIRECT 0x00000020 /* Use O_DIRECT */
#define DEV_O_DIRECT_TESTED 0x00000040 /* DEV_O_DIRECT is reliable */
#define DEV_OPEN_FAILURE 0x00000080 /* Has last open failed? */
#define DEV_USED_FOR_LV 0x00000100 /* Is device used for an LV */
#define DEV_ASSUMED_FOR_LV 0x00000200 /* Is device assumed for an LV */
#define DEV_NOT_O_NOATIME 0x00000400 /* Don't use O_NOATIME */
/*
* Support for external device info.
* Any new external device info source needs to be
* registered using EXT_REGISTER macro in dev-ext.c.
*/
typedef enum dev_ext_e {
DEV_EXT_NONE,
DEV_EXT_UDEV,
DEV_EXT_NUM
} dev_ext_t;
struct dev_ext {
int enabled;
dev_ext_t src;
void *handle;
};
/*
* All devices in LVM will be represented by one of these.
* pointer comparisons are valid.
*/
struct device {
struct dm_list aliases; /* struct dm_str_list */
dev_t dev;
/* private */
int fd;
int open_count;
int error_count;
int max_error_count;
int phys_block_size;
int block_size;
int read_ahead;
uint32_t flags;
unsigned size_seqno;
uint64_t size;
uint64_t end;
struct dm_list open_list;
struct dev_ext ext;
const char *vgid; /* if device is an LV */
const char *lvid; /* if device is an LV */
char pvid[ID_LEN + 1]; /* if device is a PV */
char _padding[7];
};
struct device_list {
struct dm_list list;
struct device *dev;
};
struct device_id_list {
struct dm_list list;
struct device *dev;
char pvid[ID_LEN + 1];
};
struct device_area {
struct device *dev;
uint64_t start; /* Bytes */
uint64_t size; /* Bytes */
};
/*
* We'll collect the results of this many async reads
* in one system call. It shouldn't matter much what
* number is used here.
*/
#define MAX_GET_EVENTS 16
struct dev_async_context {
io_context_t aio_ctx;
struct io_event events[MAX_GET_EVENTS];
};
struct dev_async_io {
char *buf;
struct iocb iocb;
struct device *dev;
uint32_t buf_len; /* size of buf */
uint32_t len; /* size of submitted io */
int done;
int result;
};
/*
* Support for external device info.
*/
const char *dev_ext_name(struct device *dev);
int dev_ext_enable(struct device *dev, dev_ext_t src);
int dev_ext_disable(struct device *dev);
struct dev_ext *dev_ext_get(struct device *dev);
int dev_ext_release(struct device *dev);
/*
* Increment current dev_size_seqno.
* This is used to control lifetime
* of cached device size.
*/
void dev_size_seqno_inc(void);
/*
* All io should use these routines.
*/
int dev_get_block_size(struct device *dev, unsigned int *phys_block_size, unsigned int *block_size);
int dev_get_size(struct device *dev, uint64_t *size);
int dev_get_read_ahead(struct device *dev, uint32_t *read_ahead);
int dev_discard_blocks(struct device *dev, uint64_t offset_bytes, uint64_t size_bytes);
/* Use quiet version if device number could change e.g. when opening LV */
int dev_open(struct device *dev);
int dev_open_quiet(struct device *dev);
int dev_open_flags(struct device *dev, int flags, int direct, int quiet);
int dev_open_readonly(struct device *dev);
int dev_open_readonly_buffered(struct device *dev);
int dev_open_readonly_quiet(struct device *dev);
int dev_close(struct device *dev);
int dev_close_immediate(struct device *dev);
void dev_close_all(void);
int dev_test_excl(struct device *dev);
int dev_fd(struct device *dev);
const char *dev_name(const struct device *dev);
int dev_read(struct device *dev, uint64_t offset, size_t len, void *buffer);
int dev_read_circular(struct device *dev, uint64_t offset, size_t len,
uint64_t offset2, size_t len2, char *buf);
int dev_write(struct device *dev, uint64_t offset, size_t len, void *buffer);
int dev_append(struct device *dev, size_t len, char *buffer);
int dev_set(struct device *dev, uint64_t offset, size_t len, int value);
void dev_flush(struct device *dev);
struct device *dev_create_file(const char *filename, struct device *dev,
struct dm_str_list *alias, int use_malloc);
void dev_destroy_file(struct device *dev);
/* Return a valid device name from the alias list; NULL otherwise */
const char *dev_name_confirmed(struct device *dev, int quiet);
struct dev_async_context *dev_async_context_setup(unsigned async_event_count);
struct dev_async_io *dev_async_io_alloc(int buf_len);
void dev_async_context_destroy(struct dev_async_context *ac);
void dev_async_io_destroy(struct dev_async_io *aio);
int dev_async_read_submit(struct dev_async_context *ac, struct dev_async_io *aio,
struct device *dev, uint32_t len, uint64_t offset, int *nospace);
int dev_async_getevents(struct dev_async_context *ac, int wait_count, struct timespec *timeout);
#endif
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