automount: make user unmounting for automount units more debuggable

Let's add an explicit log message plus an error state for automount
units, if users explicitly unmounted our autofs mount.

Prompted by: #17448

diff --git a/src/core/automount.c b/src/core/automount.c
index 16b9104171c5657987a71ea139edb0ec7efc83f4..df32b8e6fbbb940b4f58fa753590d5ea53b1e6f2 100644 (file)
--- a/src/core/automount.c
+++ b/src/core/automount.c
@@ -971,6 +971,12 @@ static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, vo
         assert(a);
         assert(fd == a->pipe_fd);
 
+        if (events & (EPOLLHUP|EPOLLERR)) {
+                log_unit_error(UNIT(a), "Got hangup/error on autofs pipe from kernel. Likely our automount point has been unmounted by someone or something else?");
+                automount_enter_dead(a, AUTOMOUNT_FAILURE_UNMOUNTED);
+                return 0;
+        }
+
         if (events != EPOLLIN) {
                 log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
                 goto fail;
@@ -1070,6 +1076,7 @@ static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
         [AUTOMOUNT_FAILURE_RESOURCES] = "resources",
         [AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
         [AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
+        [AUTOMOUNT_FAILURE_UNMOUNTED] = "unmounted",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);

diff --git a/src/core/automount.h b/src/core/automount.h
index 21dd1c07744adc8ee29064ae53900bc5b950e754..7a1234b88c7bd8557dcfcb1541313b653e61f4ae 100644 (file)
--- a/src/core/automount.h
+++ b/src/core/automount.h
@@ -8,6 +8,7 @@ typedef struct Automount Automount;
 typedef enum AutomountResult {
         AUTOMOUNT_SUCCESS,
         AUTOMOUNT_FAILURE_RESOURCES,
+        AUTOMOUNT_FAILURE_UNMOUNTED,
         AUTOMOUNT_FAILURE_START_LIMIT_HIT,
         AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT,
         _AUTOMOUNT_RESULT_MAX,