dotlocks: When locking using hard links, make sure the dotlock's timestamp is new...

diff --git a/src/lib/file-dotlock.c b/src/lib/file-dotlock.c
index 271f34494802493c5c0b0d69c68ca6000a143545..ba12664b8b1a6b8f5fb3ec49de7c2921ee66ed26 100644 (file)
--- a/src/lib/file-dotlock.c
+++ b/src/lib/file-dotlock.c
@@ -316,11 +316,12 @@ static int file_write_pid(int fd, const char *path, bool nfs_flush)
 }
 
 static int try_create_lock_hardlink(struct lock_info *lock_info, bool write_pid,
-                                   string_t *tmp_path)
+                                   string_t *tmp_path, time_t now)
 {
        const char *temp_prefix = lock_info->set->temp_prefix;
        const char *p;
        mode_t old_mask;
+       struct stat st;
 
        if (lock_info->temp_path == NULL) {
                /* we'll need our temp file first. */
@@ -366,6 +367,14 @@ static int try_create_lock_hardlink(struct lock_info *lock_info, bool write_pid,
                }
 
                 lock_info->temp_path = str_c(tmp_path);
+       } else if (fstat(lock_info->fd, &st) < 0) {
+               i_error("fstat(%s) failed: %m", lock_info->temp_path);
+               return -1;
+       } else if (st.st_ctime < now) {
+               /* we've been waiting for a while.
+                  refresh the file's timestamp. */
+               if (utime(lock_info->temp_path, NULL) < 0)
+                       i_error("utime(%s) failed: %m", lock_info->temp_path);
        }
 
        if (nfs_safe_link(lock_info->temp_path,
@@ -520,7 +529,7 @@ dotlock_create(struct dotlock *dotlock, enum dotlock_create_flags flags,
                        ret = set->use_excl_lock ?
                                try_create_lock_excl(&lock_info, write_pid) :
                                try_create_lock_hardlink(&lock_info, write_pid,
-                                                        tmp_path);
+                                                        tmp_path, now);
                        if (ret != 0)
                                break;
                }