1
0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-21 13:34:40 +03:00
lvm2/libdm/ioctl/libdevmapper.c

397 lines
6.8 KiB
C
Raw Normal View History

/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
*
* This file is released under the LGPL.
*/
#include "libdevmapper.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <linux/dm-ioctl.h>
#include <linux/kdev_t.h>
#define DEV_DIR "/dev/"
#define ALIGNMENT sizeof(int)
static char _dm_dir[PATH_MAX] = DEV_DIR DM_DIR;
/*
* Library users can provide their own logging
* function.
*/
static void _default_log(int level, const char *file, int line,
const char *f, ...)
{
va_list ap;
va_start(ap, f);
vfprintf(stderr, f, ap);
va_end(ap);
fprintf(stderr, "\n");
}
static dm_log_fn _log = _default_log;
void dm_log_init(dm_log_fn fn)
{
_log = fn;
}
#define log(msg, x...) _log(1, __FILE__, __LINE__, msg, ## x)
struct target {
unsigned long long start;
unsigned long long length;
char *type;
char *params;
struct target *next;
};
struct dm_task {
int type;
char *dev_name;
struct target *head, *tail;
struct dm_ioctl *dmi;
};
struct dm_task *dm_task_create(int type)
{
struct dm_task *dmt = malloc(sizeof(*dmt));
if (!dmt)
return NULL;
memset(dmt, 0, sizeof(*dmt));
dmt->type = type;
return dmt;
}
void dm_task_destroy(struct dm_task *dmt)
{
struct target *t, *n;
for (t = dmt->head; t; t = n) {
n = t->next;
free(t);
}
if (dmt->dmi)
free(dmt->dmi);
free(dmt);
}
int dm_task_set_name(struct dm_task *dmt, const char *name)
{
if (dmt->dev_name)
free(dmt->dev_name);
return (dmt->dev_name = strdup(name)) ? 1 : 0;
}
int dm_task_get_info(struct dm_task *dmt, struct dm_info *info)
{
if (!dmt->dmi)
return 0;
info->exists = dmt->dmi->exists;
info->suspended = dmt->dmi->suspend;
info->open_count = dmt->dmi->open_count;
info->major = dmt->dmi->major;
info->minor = dmt->dmi->minor;
info->target_count = dmt->dmi->target_count;
return 1;
}
static struct target *_create_target(unsigned long long start,
unsigned long long len,
const char *type, const char *params)
{
struct target *t = malloc(sizeof(*t));
if (!t)
return NULL;
memset(t, 0, sizeof(*t));
if (!(t->params = strdup(params))) {
log("Out of memory");
goto bad;
}
if (!(t->type = strdup(type))) {
log("Out of memory");
goto bad;
}
t->start = start;
t->length = len;
return t;
bad:
free(t->params);
free(t->type);
free(t);
return NULL;
}
int dm_task_add_target(struct dm_task *dmt,
unsigned long long start,
unsigned long long size,
const char *ttype,
const char *params)
{
struct target *t = _create_target(start, size, ttype, params);
if (!t)
return 0;
if (!dmt->head)
dmt->head = dmt->tail = t;
else {
dmt->tail->next = t;
dmt->tail = t;
}
return 1;
}
static void *_align(void *ptr, unsigned int align)
{
align--;
return (void *) (((unsigned long) ptr + align) & ~align);
}
static void *_add_target(struct target *t, void *out, void *end)
{
void *out_sp = out;
struct dm_target_spec sp;
int len;
const char no_space[] = "Ran out of memory building ioctl parameter";
out += sizeof(struct dm_target_spec);
if (out >= end) {
log(no_space);
return NULL;
}
sp.status = 0;
sp.sector_start = t->start;
sp.length = t->length;
strncpy(sp.target_type, t->type, sizeof(sp.target_type));
len = strlen(t->params);
if ((out + len + 1) >= end) {
log(no_space);
log("t->params= '%s'", t->params);
return NULL;
}
strcpy((char *) out, t->params);
out += len + 1;
/* align next block */
out = _align(out, ALIGNMENT);
sp.next = out - out_sp;
memcpy(out_sp, &sp, sizeof(sp));
return out;
}
static struct dm_ioctl *_flatten(struct dm_task *dmt)
{
struct dm_ioctl *dmi;
struct target *t;
size_t len = sizeof(struct dm_ioctl);
void *b, *e;
int count = 0;
for (t = dmt->head; t; t = t->next) {
len += sizeof(struct dm_target_spec);
len += strlen(t->params) + 1 + ALIGNMENT;
count++;
}
if (!(dmi = malloc(len)))
return NULL;
dmi->data_size = len;
strncpy(dmi->name, dmt->dev_name, sizeof(dmi->name));
dmi->suspend = (dmt->type == DM_DEVICE_SUSPEND) ? 1 : 0;
dmi->open_count = 0;
dmi->minor = -1;
dmi->target_count = count;
b = (void *) (dmi + 1);
e = (void *) ((char *) dmi + len);
for (t = dmt->head; t; t = t->next)
if (!(b = _add_target(t, b, e)))
goto bad;
return dmi;
bad:
free(dmi);
return NULL;
}
static void _build_dev_path(char *buffer, size_t len, const char *dev_name)
{
snprintf(buffer, len, "/dev/%s/%s", DM_DIR, dev_name);
}
static int _add_dev_node(const char *dev_name, dev_t dev)
{
char path[PATH_MAX];
struct stat info;
_build_dev_path(path, sizeof(path), dev_name);
if (stat(path, &info) >= 0) {
if (!S_ISBLK(info.st_mode)) {
log("A non-block device file at '%s' "
"is already present", path);
return 0;
}
if (info.st_rdev == dev)
return 1;
if (unlink(path) < 0) {
log("Unable to unlink device node for '%s'", dev_name);
return 0;
}
}
if (mknod(path, S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP, dev) < 0) {
log("Unable to make device node for '%s'", dev_name);
return 0;
}
return 1;
}
static int _rm_dev_node(const char *dev_name)
{
char path[PATH_MAX];
struct stat info;
_build_dev_path(path, sizeof(path), dev_name);
if (stat(path, &info) < 0)
return 1;
if (unlink(path) < 0) {
log("Unable to unlink device node for '%s'", dev_name);
return 0;
}
return 1;
}
int dm_task_run(struct dm_task *dmt)
{
int fd = -1;
struct dm_ioctl *dmi = _flatten(dmt);
unsigned int command;
char control[PATH_MAX];
if (!dmi) {
log("Couldn't create ioctl argument");
return 0;
}
snprintf(control, sizeof(control), "%s/control", _dm_dir);
if ((fd = open(control, O_RDWR)) < 0) {
log("Couldn't open device-mapper control device");
goto bad;
}
switch (dmt->type) {
case DM_DEVICE_CREATE:
command = DM_CREATE;
break;
case DM_DEVICE_RELOAD:
command = DM_RELOAD;
break;
case DM_DEVICE_REMOVE:
command = DM_REMOVE;
break;
case DM_DEVICE_SUSPEND:
command = DM_SUSPEND;
break;
case DM_DEVICE_RESUME:
command = DM_SUSPEND;
break;
case DM_DEVICE_INFO:
command = DM_INFO;
break;
default:
log("Internal error: unknown device-mapper task %d",
dmt->type);
goto bad;
}
if (ioctl(fd, command, dmi) < 0) {
log("device-mapper ioctl cmd %d failed: %s", dmt->type,
strerror(errno));
goto bad;
}
switch (dmt->type) {
case DM_DEVICE_CREATE:
_add_dev_node(dmt->dev_name, MKDEV(dmi->major, dmi->minor));
break;
case DM_DEVICE_REMOVE:
_rm_dev_node(dmt->dev_name);
break;
}
dmt->dmi = dmi;
return 1;
bad:
free(dmi);
if (fd >= 0)
close(fd);
return 0;
}
int dm_set_dev_dir(const char *dir)
{
2001-11-21 22:20:41 +03:00
snprintf(_dm_dir, sizeof(_dm_dir), "%s%s", dir, DM_DIR);
return 1;
}
const char *dm_dir(void)
{
return _dm_dir;
}