Using the O_CLOEXEC flag on open(2) caused the pidfile lock to be lost

when the child process execs daemon's target program thanks to flock(2)
semantics. So, we apparently have to leak the open pidfile's file
descriptor to keep the lock for the pidfile(3) functions to work properly.

Test case demonstrated by trociny:

ref8-amd64:/home/trociny% uname -r
8.2-STABLE
ref8-amd64:/home/trociny% daemon -p /tmp/sleep.pid sleep 10
ref8-amd64:/home/trociny% daemon -p /tmp/sleep.pid sleep 10
daemon: process already running, pid: 19799

kopusha:~% uname -r
10.0-CURRENT
kopusha:~% daemon -p /tmp/sleep.pid sleep 10
kopusha:~% daemon -p /tmp/sleep.pid sleep 10
kopusha:~%
This commit is contained in:
Guy Helmer 2012-02-06 14:11:24 +00:00
parent ade215fd5a
commit 000d6ce285

View File

@ -124,7 +124,7 @@ pidfile_open(const char *path, mode_t mode, pid_t *pidptr)
* pidfile_write() can be called multiple times.
*/
fd = flopen(pfh->pf_path,
O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NONBLOCK, mode);
O_WRONLY | O_CREAT | O_TRUNC | O_NONBLOCK, mode);
if (fd == -1) {
if (errno == EWOULDBLOCK && pidptr != NULL) {
count = 20;