diff --git a/src/basic/btrfs-util.c b/src/basic/btrfs-util.c
index 376844b7b1..0308048b7f 100644
--- a/src/basic/btrfs-util.c
+++ b/src/basic/btrfs-util.c
@@ -877,7 +877,7 @@ int btrfs_subvol_set_subtree_quota_limit(const char *path, uint64_t subvol_id, u
 
 int btrfs_resize_loopback_fd(int fd, uint64_t new_size, bool grow_only) {
         struct btrfs_ioctl_vol_args args = {};
-        char p[SYS_BLOCK_PATH_MAX("/loop/backing_file")];
+        char p[SYS_BLOCK_PATH_MAX("/loop/backing_file")], q[DEV_NUM_PATH_MAX];
         _cleanup_free_ char *backing = NULL;
         _cleanup_close_ int loop_fd = -1, backing_fd = -1;
         struct stat st;
@@ -922,8 +922,8 @@ int btrfs_resize_loopback_fd(int fd, uint64_t new_size, bool grow_only) {
         if (grow_only && new_size < (uint64_t) st.st_size)
                 return -EINVAL;
 
-        xsprintf_sys_block_path(p, NULL, dev);
-        loop_fd = open(p, O_RDWR|O_CLOEXEC|O_NOCTTY);
+        xsprintf_dev_num_path(q, "block", dev);
+        loop_fd = open(q, O_RDWR|O_CLOEXEC|O_NOCTTY);
         if (loop_fd < 0)
                 return -errno;
 
diff --git a/src/shared/machine-pool.c b/src/shared/machine-pool.c
index 4fedeb17e3..df56492e7b 100644
--- a/src/shared/machine-pool.c
+++ b/src/shared/machine-pool.c
@@ -378,14 +378,21 @@ int grow_machine_directory(void) {
                 new_size = old_size + max_add;
 
         r = btrfs_resize_loopback("/var/lib/machines", new_size, true);
-        if (r <= 0)
-                return r;
+        if (r < 0)
+                return log_debug_errno(r, "Failed to resize loopback: %m");
+        if (r == 0)
+                return 0;
 
         /* Also bump the quota, of both the subvolume leaf qgroup, as
          * well as of any subtree quota group by the same id but a
          * higher level, if it exists. */
-        (void) btrfs_qgroup_set_limit("/var/lib/machines", 0, new_size);
-        (void) btrfs_subvol_set_subtree_quota_limit("/var/lib/machines", 0, new_size);
+        r = btrfs_qgroup_set_limit("/var/lib/machines", 0, new_size);
+        if (r < 0)
+                log_debug_errno(r, "Failed to set btrfs limit: %m");
+
+        r = btrfs_subvol_set_subtree_quota_limit("/var/lib/machines", 0, new_size);
+        if (r < 0)
+                log_debug_errno(r, "Failed to set btrfs subtree limit: %m");
 
         log_info("Grew /var/lib/machines btrfs loopback file system to %s.", format_bytes(buf, sizeof(buf), new_size));
         return 1;