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);
}
/**
* mnt_pretty_path:
* @path: any path
* @cache: NULL or pointer to the cache
*
* Converts path:
* - to the absolute path
* - /dev/dm-N to /dev/mapper/name
* - /dev/loopN to the loop backing filename
* - empty path (NULL) to 'none'
*
* Returns: newly allocated string with path, result always has to be deallocated
* by free().
*/
char *mnt_pretty_path(const char *path, struct libmnt_cache *cache)
{
char *pretty = mnt_resolve_path(path, cache);
if (!pretty)
return strdup("none");
#ifdef __linux__
/* users assume backing file name rather than /dev/loopN in
* output if the device has been initialized by mount(8).
*/
if (strncmp(pretty, "/dev/loop", 9) == 0) {
struct loopdev_cxt lc;
if (loopcxt_init(&lc, 0) || loopcxt_set_device(&lc, pretty))
goto done;
if (loopcxt_is_autoclear(&lc)) {
char *tmp = loopcxt_get_backing_file(&lc);
if (tmp) {
if (!cache)
free(pretty); /* not cached, deallocate */
return tmp; /* return backing file */
}
}
loopcxt_deinit(&lc);
}
#endif
done:
/* don't return pointer to the cache, allocate a new string */
return cache ? strdup(pretty) : pretty;
}
static void test_loop_info(const char *device, int flags, int debug)
{
struct loopdev_cxt lc;
char *p;
uint64_t u64;
loopcxt_init(&lc, flags);
loopcxt_enable_debug(&lc, debug);
if (loopcxt_set_device(&lc, device))
err(EXIT_FAILURE, "failed to set device");
p = loopcxt_get_backing_file(&lc);
printf("\tBACKING FILE: %s\n", p);
free(p);
if (loopcxt_get_offset(&lc, &u64) == 0)
printf("\tOFFSET: %jd\n", u64);
if (loopcxt_get_sizelimit(&lc, &u64) == 0)
printf("\tSIZE LIMIT: %jd\n", u64);
printf("\tAUTOCLEAR: %s\n", loopcxt_is_autoclear(&lc) ? "YES" : "NOT");
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;
}
static int printf_loopdev(struct loopdev_cxt *lc)
{
uint64_t x;
dev_t dev = 0;
ino_t ino = 0;
char *fname = NULL;
uint32_t type;
fname = loopcxt_get_backing_file(lc);
if (!fname)
return -EINVAL;
if (loopcxt_get_backing_devno(lc, &dev) == 0)
loopcxt_get_backing_inode(lc, &ino);
if (!dev && !ino) {
/*
* Probably non-root user (no permissions to
* call LOOP_GET_STATUS ioctls).
*/
printf("%s: []: (%s)",
loopcxt_get_device(lc), fname);
if (loopcxt_get_offset(lc, &x) == 0 && x)
printf(_(", offset %ju"), x);
if (loopcxt_get_sizelimit(lc, &x) == 0 && x)
printf(_(", sizelimit %ju"), x);
printf("\n");
return 0;
}
printf("%s: [%04d]:%" PRIu64 " (%s)",
loopcxt_get_device(lc), (int) dev, ino, fname);
if (loopcxt_get_offset(lc, &x) == 0 && x)
printf(_(", offset %ju"), x);
if (loopcxt_get_sizelimit(lc, &x) == 0 && x)
printf(_(", sizelimit %ju"), x);
if (loopcxt_get_encrypt_type(lc, &type) == 0) {
const char *e = loopcxt_get_crypt_name(lc);
if ((!e || !*e) && type == 1)
e = "XOR";
if (e && *e)
printf(_(", encryption %s (type %u)"), e, type);
}
printf("\n");
return 0;
}
char *loopdev_get_backing_file(const char *device)
{
struct loopdev_cxt lc;
char *res;
if (!device)
return NULL;
loopcxt_init(&lc, 0);
loopcxt_set_device(&lc, device);
res = loopcxt_get_backing_file(&lc);
loopcxt_deinit(&lc);
return res;
}
/*
* @lc: context
* @st: backing file stat or NULL
* @backing_file: filename
* @offset: offset
* @flags: LOOPDEV_FL_OFFSET if @offset should not be ignored
*
* Returns 1 if the current @lc loopdev is associated with the given backing
* file. Note that the preferred way is to use devno and inode number rather
* than filename. The @backing_file filename is poor solution usable in case
* that you don't have rights to call stat().
*
* Don't forget that old kernels provide very restricted (in size) backing
* filename by LOOP_GET_STAT64 ioctl only.
*/
int loopcxt_is_used(struct loopdev_cxt *lc,
struct stat *st,
const char *backing_file,
uint64_t offset,
int flags)
{
ino_t ino;
dev_t dev;
if (!lc)
return 0;
DBG(lc, loopdev_debug("checking %s vs. %s",
loopcxt_get_device(lc),
backing_file));
if (st && loopcxt_get_backing_inode(lc, &ino) == 0 &&
loopcxt_get_backing_devno(lc, &dev) == 0) {
if (ino == st->st_ino && dev == st->st_dev)
goto found;
/* don't use filename if we have devno and inode */
return 0;
}
/* poor man's solution */
if (backing_file) {
char *name = loopcxt_get_backing_file(lc);
int rc = name && strcmp(name, backing_file) == 0;
free(name);
if (rc)
goto found;
}
return 0;
found:
if (flags & LOOPDEV_FL_OFFSET) {
uint64_t off;
return loopcxt_get_offset(lc, &off) == 0 && off == offset;
}
return 1;
}