diff options
| -rw-r--r-- | cache.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/cache.c b/cache.c index 801e63f..900b161 100644 --- a/cache.c +++ b/cache.c @@ -161,10 +161,23 @@ static int close_lock(struct cache_slot *slot) */ static int lock_slot(struct cache_slot *slot) { - slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT | O_EXCL, + struct flock lock = { + .l_type = F_WRLCK, + .l_whence = SEEK_SET, + .l_start = 0, + .l_len = 0, + }; + + slot->lock_fd = open(slot->lock_name, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR); if (slot->lock_fd == -1) return errno; + if (fcntl(slot->lock_fd, F_SETLK, &lock) < 0) { + int saved_errno = errno; + close(slot->lock_fd); + slot->lock_fd = -1; + return saved_errno; + } if (xwrite(slot->lock_fd, slot->key, slot->keylen + 1) < 0) return errno; return 0; |