static int delete_loopback(const char *device) {
_cleanup_close_ int fd = -1;
+ struct loop_info64 info;
assert(device);
if (fd < 0)
return errno == ENOENT ? 0 : -errno;
- if (ioctl(fd, LOOP_CLR_FD, 0) >= 0)
+ if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
+ if (errno == ENXIO) /* Nothing bound, didn't do anything */
+ return 0;
+
+ return -errno;
+ }
+
+ if (ioctl(fd, LOOP_GET_STATUS64, &info) < 0) {
+ /* If the LOOP_CLR_FD above succeeded we'll see ENXIO here. */
+ if (errno == ENXIO)
+ log_debug("Successfully detached loopback device %s.", device);
+ else
+ log_debug_errno(errno, "Failed to invoke LOOP_GET_STATUS64 on loopback device %s, ignoring: %m", device); /* the LOOP_CLR_FD at least worked, let's hope for the best */
+
return 1;
+ }
- /* ENXIO: not bound, so no error */
- if (errno == ENXIO)
- return 0;
+ /* Linux makes LOOP_CLR_FD succeed whenever LO_FLAGS_AUTOCLEAR is set without actually doing
+ * anything. Very confusing. Let's hence not claim we did anything in this case. */
+ if (FLAGS_SET(info.lo_flags, LO_FLAGS_AUTOCLEAR))
+ log_debug("Successfully called LOOP_CLR_FD on a loopback device %s with autoclear set, which is a NOP.", device);
+ else
+ log_debug("Weird, LOOP_CLR_FD succeeded but the device is still attached on %s.", device);
- return -errno;
+ return -EBUSY; /* Nothing changed, the device is still attached, hence it apparently is still busy */
}
static int delete_dm(dev_t devnum) {