static void test_loop_scan(int flags, int debug)
{
struct loopdev_cxt lc;
int rc;
loopcxt_init(&lc, 0);
loopcxt_enable_debug(&lc, debug);
if (loopcxt_init_iterator(&lc, flags))
err(EXIT_FAILURE, "iterator initlization failed");
while((rc = loopcxt_next(&lc)) == 0) {
const char *device = loopcxt_get_device(&lc);
if (flags & LOOPITER_FL_USED) {
char *backing = loopcxt_get_backing_file(&lc);
printf("\t%s: %s\n", device, backing);
free(backing);
} else
printf("\t%s\n", device);
}
if (rc < 0)
err(EXIT_FAILURE, "loopdevs scanning failed");
loopcxt_deinit(&lc);
}
/*
* Returns number of loop devices associated with @file, if only one loop
* device is associeted with the given @filename and @loopdev is not NULL then
* @loopdev returns name of the device.
*/
int loopdev_count_by_backing_file(const char *filename, char **loopdev)
{
struct loopdev_cxt lc;
int count = 0;
if (!filename)
return -1;
loopcxt_init(&lc, 0);
if (loopcxt_init_iterator(&lc, LOOPITER_FL_USED))
return -1;
while(loopcxt_next(&lc) == 0) {
char *backing = loopcxt_get_backing_file(&lc);
if (!backing || strcmp(backing, filename)) {
free(backing);
continue;
}
free(backing);
if (loopdev && count == 0)
*loopdev = loopcxt_strdup_device(&lc);
count++;
}
loopcxt_deinit(&lc);
if (loopdev && count > 1) {
free(*loopdev);
*loopdev = NULL;
}
return count;
}
/*
* Returns: 0 = success, < 0 error, 1 not found
*/
int loopcxt_find_by_backing_file(struct loopdev_cxt *lc, const char *filename,
uint64_t offset, int flags)
{
int rc, hasst;
struct stat st;
if (!filename)
return -EINVAL;
hasst = !stat(filename, &st);
rc = loopcxt_init_iterator(lc, LOOPITER_FL_USED);
if (rc)
return rc;
while ((rc = loopcxt_next(lc)) == 0) {
if (loopcxt_is_used(lc, hasst ? &st : NULL,
filename, offset, flags))
break;
}
loopcxt_deinit_iterator(lc);
return rc;
}
/*
* Note that LOOP_CTL_GET_FREE ioctl is supported since kernel 3.1. In older
* kernels we have to check all loop devices to found unused one.
*
* See kernel commit 770fe30a46a12b6fb6b63fbe1737654d28e8484.
*/
int loopcxt_find_unused(struct loopdev_cxt *lc)
{
int rc = -1;
DBG(lc, loopdev_debug("find_unused requested"));
if (lc->flags & LOOPDEV_FL_CONTROL) {
int ctl = open(_PATH_DEV_LOOPCTL, O_RDWR);
if (ctl >= 0)
rc = ioctl(ctl, LOOP_CTL_GET_FREE);
if (rc >= 0) {
char name[16];
snprintf(name, sizeof(name), "loop%d", rc);
rc = loopiter_set_device(lc, name);
}
if (ctl >= 0)
close(ctl);
DBG(lc, loopdev_debug("find_unused by loop-control [rc=%d]", rc));
}
if (rc < 0) {
rc = loopcxt_init_iterator(lc, LOOPITER_FL_FREE);
if (rc)
return rc;
rc = loopcxt_next(lc);
loopcxt_deinit_iterator(lc);
DBG(lc, loopdev_debug("find_unused by scan [rc=%d]", rc));
}
return rc;
}
static int delete_all_loops(struct loopdev_cxt *lc)
{
int res = 0;
if (loopcxt_init_iterator(lc, LOOPITER_FL_USED))
return -1;
while (loopcxt_next(lc) == 0)
res += delete_loop(lc);
loopcxt_deinit_iterator(lc);
return res;
}
static int show_all_loops(struct loopdev_cxt *lc, const char *file,
uint64_t offset, int flags)
{
struct stat sbuf, *st = &sbuf;
if (loopcxt_init_iterator(lc, LOOPITER_FL_USED))
return -1;
if (!file || stat(file, st))
st = NULL;
while (loopcxt_next(lc) == 0) {
if (file && !loopcxt_is_used(lc, st, file, offset, flags))
continue;
printf_loopdev(lc);
}
loopcxt_deinit_iterator(lc);
return 0;
}