Commit cc0191ae authored by Neil Horman's avatar Neil Horman Committed by David S. Miller
Browse files

[IPVS]: Fix state variable on failure to start ipvs threads 



ip_vs currently fails to reset its ip_vs_sync_state variable if the
sync thread fails to start properly.  The result is that the kernel
will report a running daemon when their actuall is none.

If you issue the following commands:

1. ipvsadm --start-daemon master --mcast-interface bla
2. ipvsadm -L --daemon
3. ipvsadm --stop-daemon master

Assuming that bla is not an actual interface, step 2 should return no
data, but instead returns:

$ ipvsadm -L --daemon
master sync daemon (mcast=bla, syncid=0)

Signed-off-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 28121617

net/ipv4/ipvs/ip_vs_sync.c

+39 −2
Original line number Diff line number Diff line
@@ -67,6 +67,11 @@ struct ip_vs_sync_conn_options { 
	struct ip_vs_seq        out_seq;        /* outgoing seq. struct */

};



struct ip_vs_sync_thread_data {

	struct completion *startup;

	int state;

};



#define IP_VS_SYNC_CONN_TIMEOUT (3*60*HZ)

#define SIMPLE_CONN_SIZE  (sizeof(struct ip_vs_sync_conn))

#define FULL_CONN_SIZE  \
@@ -751,6 +756,7 @@ static int sync_thread(void *startup) 
	mm_segment_t oldmm;

	int state;

	const char *name;

	struct ip_vs_sync_thread_data *tinfo = startup;



	/* increase the module use count */

	ip_vs_use_count_inc();
@@ -789,7 +795,14 @@ static int sync_thread(void *startup) 
	add_wait_queue(&sync_wait, &wait);



	set_sync_pid(state, current->pid);

	complete((struct completion *)startup);

	complete(tinfo->startup);



	/*

	 * once we call the completion queue above, we should

	 * null out that reference, since its allocated on the

	 * stack of the creating kernel thread

	 */

	tinfo->startup = NULL;



	/* processing master/backup loop here */

	if (state == IP_VS_STATE_MASTER)
@@ -801,6 +814,14 @@ static int sync_thread(void *startup) 
	remove_wait_queue(&sync_wait, &wait);



	/* thread exits */



	/*

	 * If we weren't explicitly stopped, then we

	 * exited in error, and should undo our state

	 */

	if ((!stop_master_sync) && (!stop_backup_sync))

		ip_vs_sync_state -= tinfo->state;



	set_sync_pid(state, 0);

	IP_VS_INFO("sync thread stopped!\n");
@@ -812,6 +833,11 @@ static int sync_thread(void *startup) 
	set_stop_sync(state, 0);

	wake_up(&stop_sync_wait);



	/*

	 * we need to free the structure that was allocated

	 * for us in start_sync_thread

	 */

	kfree(tinfo);

	return 0;

}
@@ -838,11 +864,19 @@ int start_sync_thread(int state, char *mcast_ifn, __u8 syncid) 
{

	DECLARE_COMPLETION_ONSTACK(startup);

	pid_t pid;

	struct ip_vs_sync_thread_data *tinfo;



	if ((state == IP_VS_STATE_MASTER && sync_master_pid) ||

	    (state == IP_VS_STATE_BACKUP && sync_backup_pid))

		return -EEXIST;



	/*

	 * Note that tinfo will be freed in sync_thread on exit

	 */

	tinfo = kmalloc(sizeof(struct ip_vs_sync_thread_data), GFP_KERNEL);

	if (!tinfo)

		return -ENOMEM;



	IP_VS_DBG(7, "%s: pid %d\n", __FUNCTION__, current->pid);

	IP_VS_DBG(7, "Each ip_vs_sync_conn entry need %Zd bytes\n",

		  sizeof(struct ip_vs_sync_conn));
@@ -858,8 +892,11 @@ int start_sync_thread(int state, char *mcast_ifn, __u8 syncid) 
		ip_vs_backup_syncid = syncid;

	}



	tinfo->state = state;

	tinfo->startup = &startup;



  repeat:

	if ((pid = kernel_thread(fork_sync_thread, &startup, 0)) < 0) {

	if ((pid = kernel_thread(fork_sync_thread, tinfo, 0)) < 0) {

		IP_VS_ERR("could not create fork_sync_thread due to %d... "

			  "retrying.\n", pid);

		msleep_interruptible(1000);

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