automount: handle expire_tokens when the mount unit changes its state (#3434)

This basically reverts 7b2fd9d51259f6cf350791434e640ac3519acc6c ("core:
remove duplicate code in automount_update_mount()").

This was not duplicate code. The expire_tokens need to be handled as well:
Send 0 == success for MOUNT_DEAD (umount successful), do nothing for
MOUNT_UNMOUNTING (not yet done) and an error for everything else.

Otherwise the automount logic will assume unmounting is not done and will
not send any new requests for mounting. As a result, the corresponding
mount unit is never mounted.

Without this, automounts with TimeoutIdleSec= are broken. Once the idle
timeout triggered a umount, any access to the corresponding filesystem
hangs forever.

Fixes #3332.

diff --git a/src/core/automount.c b/src/core/automount.c
index f06d837e300c48262d9df7af6d21a922f77195df..85803a9c4ab355b101f42d518a024886437a3c2c 100644 (file)
--- a/src/core/automount.c
+++ b/src/core/automount.c
@@ -502,6 +502,20 @@ static void automount_trigger_notify(Unit *u, Unit *other) {
                 automount_set_state(a, AUTOMOUNT_RUNNING);
         }
 
+        if (IN_SET(MOUNT(other)->state,
+                   MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
+                   MOUNT_MOUNTED, MOUNT_REMOUNTING,
+                   MOUNT_MOUNTING_SIGTERM, MOUNT_MOUNTING_SIGKILL,
+                   MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
+                   MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
+                   MOUNT_FAILED)) {
+
+                (void) automount_send_ready(a, a->expire_tokens, -ENODEV);
+        }
+
+        if (MOUNT(other)->state == MOUNT_DEAD)
+                (void) automount_send_ready(a, a->expire_tokens, 0);
+
         /* The mount is in some unhappy state now, let's unfreeze any waiting clients */
         if (IN_SET(MOUNT(other)->state,
                    MOUNT_DEAD, MOUNT_UNMOUNTING,