Fix "out of memory" error

Drop the no_memory() call from zpool_in_use() when reading the
label fails and instead return the error to the caller.  This
prevents a misleading "internal error: out of memory" error
when the label can't be read.  This will result in is_spare()
returning B_FALSE instead of aborting, which is already safely
handled.

Furthermore, on Linux it's possible for EREMOTEIO to returned
by an NVMVe device if the device has been low-level formatted
and not rescanned.  In this case we want to fallback to the
legacy scanning method and read any of the labels we can.

Signed-off-by: Brian Behlendorf <[email protected]>
Issue openzfs#13538

lib/libzfs/libzfs_import.c

@@ -291,10 +291,8 @@ zpool_in_use(libzfs_handle_t *hdl, int fd, pool_state_t *state, char **namestr,
 
 	*inuse = B_FALSE;
 
-	if (zpool_read_label(fd, &config, NULL) != 0) {
-		(void) no_memory(hdl);
+	if (zpool_read_label(fd, &config, NULL) != 0)
 		return (-1);
-	}
 
 	if (config == NULL)
 		return (0);

lib/libzutil/zutil_import.c

@@ -1056,10 +1056,21 @@ zpool_read_label(int fd, nvlist_t **config, int *num_labels)
 				case EINVAL:
 					break;
 				case EINPROGRESS:
-					// This shouldn't be possible to
-					// encounter, die if we do.
+					/*
+					 * This shouldn't be possible to
+					 * encounter, die if we do.
+					 */
 					ASSERT(B_FALSE);
 					zfs_fallthrough;
+				case EREMOTEIO:
+					/*
+					 * May be returned by an NVMe device
+					 * which is visible in /dev/ but due
+					 * to a low-level format change, or
+					 * other error, needsto be rescanned.
+					 * Try the slow method.
+					 */
+					zfs_fallthrough;
 				case EOPNOTSUPP:
 				case ENOSYS:
 					do_slow = B_TRUE;