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-rw-r--r--cache.c15
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;