ask-password: improve log message when inotify limit is reached

When inotify_add_watch() fails because of the inotify limit, errno is
set to ENOSPC and then gets shown to users as "No space left on device".
That is very confusing and requires in-depth knowledge of the C library.
Therefore, show user-friendly message when inotify limit is reached.

Fixes #6030.

diff --git a/src/tty-ask-password-agent/tty-ask-password-agent.c b/src/tty-ask-password-agent/tty-ask-password-agent.c
index ba2e1d37f0e03d4a8d0abe17c9417640d582b297..1aa90b6040078667505c3f784802b487a04b3bcc 100644 (file)
--- a/src/tty-ask-password-agent/tty-ask-password-agent.c
+++ b/src/tty-ask-password-agent/tty-ask-password-agent.c
@@ -519,8 +519,12 @@ static int watch_passwords(void) {
         if (notify < 0)
                 return log_error_errno(errno, "Failed to allocate directory watch: %m");
 
-        if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_MOVED_TO) < 0)
-                return log_error_errno(errno, "Failed to add /run/systemd/ask-password to directory watch: %m");
+        if (inotify_add_watch(notify, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_MOVED_TO) < 0) {
+                if (errno == ENOSPC)
+                        return log_error_errno(errno, "Failed to add /run/systemd/ask-password to directory watch: inotify watch limit reached");
+                else
+                        return log_error_errno(errno, "Failed to add /run/systemd/ask-password to directory watch: %m");
+        }
 
         assert_se(sigemptyset(&mask) >= 0);
         assert_se(sigset_add_many(&mask, SIGINT, SIGTERM, -1) >= 0);