dsync: Fix .dovecot-sync.lock timeout checking

Whenever the lock file was recreated, the lock timeout was reset. Switched
to using file_create_locked(), which already solves this problem and has
compatible locking.

diff --git a/src/doveadm/dsync/dsync-brain.c b/src/doveadm/dsync/dsync-brain.c
index d6e584594d2ed92a9dceed55b72cd2a3c52d7a2a..7c681c087db138c186535eae871b8b4cf2e00dcc 100644 (file)
--- a/src/doveadm/dsync/dsync-brain.c
+++ b/src/doveadm/dsync/dsync-brain.c
@@ -5,6 +5,7 @@
 #include "hash.h"
 #include "hostpid.h"
 #include "str.h"
+#include "file-create-locked.h"
 #include "process-title.h"
 #include "settings-parser.h"
 #include "master-service.h"
@@ -381,8 +382,12 @@ int dsync_brain_deinit(struct dsync_brain **_brain, enum mail_error *error_r)
 static int
 dsync_brain_lock(struct dsync_brain *brain, const char *remote_hostname)
 {
-       struct stat st1, st2;
-       const char *home;
+       const struct file_create_settings lock_set = {
+               .lock_timeout_secs = brain->lock_timeout,
+               .lock_method = FILE_LOCK_METHOD_FCNTL,
+       };
+       const char *home, *error;
+       bool created;
        int ret;
 
        if ((ret = strcmp(remote_hostname, my_hostdomain())) < 0) {
@@ -408,49 +413,13 @@ dsync_brain_lock(struct dsync_brain *brain, const char *remote_hostname)
                process_title_set(dsync_brain_get_proctitle_full(brain, DSYNC_BRAIN_TITLE_LOCKING));
        brain->lock_path = p_strconcat(brain->pool, home,
                                       "/"DSYNC_LOCK_FILENAME, NULL);
-       for (;;) {
-               brain->lock_fd = creat(brain->lock_path, 0600);
-               if (brain->lock_fd == -1) {
-                       i_error("Couldn't create lock %s: %m",
-                               brain->lock_path);
-                       break;
-               }
-
-               if (file_wait_lock(brain->lock_fd, brain->lock_path, F_WRLCK,
-                                  FILE_LOCK_METHOD_FCNTL, brain->lock_timeout,
-                                  &brain->lock) <= 0) {
-                       if (errno == EAGAIN) {
-                               i_error("Couldn't lock %s: Timed out after %u seconds",
-                                       brain->lock_path, brain->lock_timeout);
-                       } else {
-                               i_error("Couldn't lock %s: %m", brain->lock_path);
-                       }
-                       break;
-               }
-               if (fstat(brain->lock_fd, &st1) < 0) {
-                       if (errno != ESTALE) {
-                               i_error("fstat(%s) failed: %m", brain->lock_path);
-                               break;
-                       }
-               } else if (stat(brain->lock_path, &st2) < 0) {
-                       if (errno != ENOENT) {
-                               i_error("stat(%s) failed: %m", brain->lock_path);
-                               break;
-                       }
-               } else if (st1.st_ino == st2.st_ino) {
-                       /* success */
-                       if (brain->verbose_proctitle)
-                               process_title_set(dsync_brain_get_proctitle(brain));
-                       return 0;
-               }
-               /* file was recreated, try again */
-               i_close_fd(&brain->lock_fd);
-       }
-       if (brain->lock_fd != -1)
-               i_close_fd(&brain->lock_fd);
+       brain->lock_fd = file_create_locked(brain->lock_path, &lock_set,
+                                           &brain->lock, &created, &error);
+       if (brain->lock_fd == -1)
+               i_error("Couldn't lock %s: %s", brain->lock_path, error);
        if (brain->verbose_proctitle)
                process_title_set(dsync_brain_get_proctitle(brain));
-       return -1;
+       return brain->lock_fd == -1 ? -1 : 0;
 }
 
 static bool dsync_brain_master_recv_handshake(struct dsync_brain *brain)