importd: automatically grow /var/lib/machines/ loopback filesystem during downloads

If /var/lib/machines is mounted as btrfs loopback file system in
/var/lib/machines.raw with this change we automatically grow the file
system as it fills up. After each 10M we write to it during imports, we
check the free disk space, and if the fill level grows beyond 66% we
increase the size of the file system to 3x the fill level (thus lowering
it to 33%).

1 files changed, 5 insertions, 3 deletions

diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index 5ab40b0410..adba8122f3 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -805,14 +805,16 @@ static int method_set_pool_limit(sd_bus *bus, sd_bus_message *message, void *use
         if (r < 0)
                 return r;
 
-        r = btrfs_resize_loopback("/var/lib/machines", limit);
-        if (r < 0 && r != -ENODEV)
+        r = btrfs_resize_loopback("/var/lib/machines", limit, false);
+        if (r == -ENOTTY)
+                return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Quota is only supported on btrfs.");
+        if (r < 0 && r != -ENODEV) /* ignore ENODEV, as that's what is returned if the file system is not on loopback */
                 return sd_bus_error_set_errnof(error, r, "Failed to adjust loopback limit: %m");
 
         r = btrfs_quota_limit("/var/lib/machines", limit);
         if (r == -ENOTTY)
                 return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Quota is only supported on btrfs.");
-        else if (r < 0)
+        if (r < 0)
                 return sd_bus_error_set_errnof(error, r, "Failed to adjust quota limit: %m");
 
         return sd_bus_reply_method_return(message, NULL);