Am Montag 07 März 2011 schrieb Or Gerlitz:
> Roland Friedwagner wrote:
> > - Fix logging semaphore key clash between iscsd and tgtd
>
> I tend to think we have that/similar clash also between multiple tgtd
> instances, e.g running two instances and using strace, I can see that
> both did "semget(0x54475444, 1, IPC_CREAT|0666)" is that also
> something we need to address?
>
> Or.
>
I think you are right!
My suggested patch did create a ipc semaphore keyid based on
the managment socket file by calling ftok(3).
To avoid to have the mgmt socket path in mgmt.c and log.c
I made it extern in mgmt.c
(for the symbol uniqueness change the name to mgmt_path).
Also log a warning if the semkey already exits (ipcs -m), but
continue to initialize tgtd.
(I think have tgtd running to serve requests has priority to
some possible logging clash with other instance.)
Suggestions/Improvements?
---------------------------------%<----------------------------------------
diff -Nurp tgt-1.0.14.orig/usr/log.c tgt-1.0.14/usr/log.c
--- tgt-1.0.14.orig/usr/log.c 2011-03-01 12:53:45.000000000 +0100
+++ tgt-1.0.14/usr/log.c 2011-03-08 12:09:16.000000000 +0100
@@ -33,7 +33,6 @@
#include "log.h"
-#define SEMKEY 0xA7L
#define LOGDBG 0
#if LOGDBG
@@ -50,6 +49,8 @@ static pid_t pid;
static int logarea_init (int size)
{
int shmid;
+ extern char mgmt_path[];
+ key_t semkey;
logdbg(stderr,"enter logarea_init\n");
@@ -109,13 +110,23 @@ static int logarea_init (int size)
shmctl(shmid, IPC_RMID, NULL);
- if ((la->semid = semget(SEMKEY, 1, 0666 | IPC_CREAT)) < 0) {
+ if ((semkey = ftok(mgmt_path, 'a')) < 0) {
+ syslog(LOG_ERR, "semkey failed %d", errno);
+ return 1;
+ }
+
+ if ((semget(semkey, 0, IPC_EXCL)) > 0) {
+ /* Semkey may exists after SIGKILL tgtd */
+ syslog(LOG_WARNING, "semkey 0x%x already exists", semkey);
+ }
+ if ((la->semid = semget(semkey, 1, 0666 | IPC_CREAT)) < 0) {
syslog(LOG_ERR, "semget failed %d", errno);
shmdt(la->buff);
shmdt(la->start);
shmdt(la);
return 1;
}
+ syslog(LOG_DAEMON, "semkey 0x%x", semkey);
la->semarg.val=1;
if (semctl(la->semid, 0, SETVAL, la->semarg) < 0) {
diff -Nurp tgt-1.0.14.orig/usr/mgmt.c tgt-1.0.14/usr/mgmt.c
--- tgt-1.0.14.orig/usr/mgmt.c 2011-03-01 12:53:45.000000000 +0100
+++ tgt-1.0.14/usr/mgmt.c 2011-03-08 11:59:04.000000000 +0100
@@ -59,6 +59,7 @@ struct mgmt_task {
};
static int ipc_fd;
+char mgmt_path[256];
static void set_show_results(struct tgtadm_rsp *rsp, int *err)
{
@@ -567,7 +568,7 @@ int ipc_init(void)
extern short control_port;
int fd, err;
struct sockaddr_un addr;
- char path[256];
+ extern char mgmt_path[];
fd = socket(AF_LOCAL, SOCK_STREAM, 0);
if (fd < 0) {
@@ -575,11 +576,11 @@ int ipc_init(void)
return -1;
}
- sprintf(path, "%s.%d", TGT_IPC_NAMESPACE, control_port);
- unlink(path);
+ sprintf(mgmt_path, "%s.%d", TGT_IPC_NAMESPACE, control_port);
+ unlink(mgmt_path);
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_LOCAL;
- strncpy(addr.sun_path, path, sizeof(addr.sun_path));
+ strncpy(addr.sun_path, mgmt_path, sizeof(addr.sun_path));
err = bind(fd, (struct sockaddr *) &addr, sizeof(addr));
if (err) {
diff -Nurp tgt-1.0.14.orig/usr/tgtadm.c tgt-1.0.14/usr/tgtadm.c
--- tgt-1.0.14.orig/usr/tgtadm.c 2011-03-01 12:53:45.000000000 +0100
+++ tgt-1.0.14/usr/tgtadm.c 2011-03-08 11:59:43.000000000 +0100
@@ -190,7 +190,7 @@ static int ipc_mgmt_connect(int *fd)
{
int err;
struct sockaddr_un addr;
- char path[256];
+ char mgmt_path[256];
*fd = socket(AF_LOCAL, SOCK_STREAM, 0);
if (*fd < 0) {
@@ -200,8 +200,8 @@ static int ipc_mgmt_connect(int *fd)
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_LOCAL;
- sprintf(path, "%s.%d", TGT_IPC_NAMESPACE, control_port);
- strncpy(addr.sun_path, path, sizeof(addr.sun_path));
+ sprintf(mgmt_path, "%s.%d", TGT_IPC_NAMESPACE, control_port);
+ strncpy(addr.sun_path, mgmt_path, sizeof(addr.sun_path));
err = connect(*fd, (struct sockaddr *) &addr, sizeof(addr));
if (err < 0)
---------------------------------%<----------------------------------------
Kind Regards,
Roland
--
Roland.Friedwagner@xxxxxxxx Phone: +43 1 31336 5377
IT Services - WU (Vienna University of Economics and Business)
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