LU-8926 llite: reduce jobstats race window

[fs/lustre-release.git] / lustre / obdclass / class_obd.c

diff --git a/lustre/obdclass/class_obd.c b/lustre/obdclass/class_obd.c
index 293b559..cf38cde 100644 (file)
--- a/lustre/obdclass/class_obd.c
+++ b/lustre/obdclass/class_obd.c
@@ -126,29 +126,29 @@ char obd_jobid_node[LUSTRE_JOBID_SIZE + 1];
 int lustre_get_jobid(char *jobid)
 {
        int jobid_len = LUSTRE_JOBID_SIZE;
 int lustre_get_jobid(char *jobid)
 {
        int jobid_len = LUSTRE_JOBID_SIZE;

+       char tmp_jobid[LUSTRE_JOBID_SIZE] = { 0 };

        int rc = 0;
        ENTRY;
 
        int rc = 0;
        ENTRY;
 

-       memset(jobid, 0, LUSTRE_JOBID_SIZE);

        /* Jobstats isn't enabled */
        if (strcmp(obd_jobid_var, JOBSTATS_DISABLE) == 0)
        /* Jobstats isn't enabled */
        if (strcmp(obd_jobid_var, JOBSTATS_DISABLE) == 0)

-               RETURN(0);
+               GOTO(out, rc = 0);

 
        /* Whole node dedicated to single job */
        if (strcmp(obd_jobid_var, JOBSTATS_NODELOCAL) == 0) {
 
        /* Whole node dedicated to single job */
        if (strcmp(obd_jobid_var, JOBSTATS_NODELOCAL) == 0) {

-               memcpy(jobid, obd_jobid_node, LUSTRE_JOBID_SIZE);
-               RETURN(0);
+               memcpy(tmp_jobid, obd_jobid_node, LUSTRE_JOBID_SIZE);
+               GOTO(out, rc = 0);

        }
 
        /* Use process name + fsuid as jobid */
        if (strcmp(obd_jobid_var, JOBSTATS_PROCNAME_UID) == 0) {
        }
 
        /* Use process name + fsuid as jobid */
        if (strcmp(obd_jobid_var, JOBSTATS_PROCNAME_UID) == 0) {

-               snprintf(jobid, LUSTRE_JOBID_SIZE, "%s.%u",
+               snprintf(tmp_jobid, LUSTRE_JOBID_SIZE, "%s.%u",

                         current_comm(),
                         from_kuid(&init_user_ns, current_fsuid()));
                         current_comm(),
                         from_kuid(&init_user_ns, current_fsuid()));

-               RETURN(0);
+               GOTO(out, rc = 0);

        }
 
        }
 

-       rc = cfs_get_environ(obd_jobid_var, jobid, &jobid_len);
+       rc = cfs_get_environ(obd_jobid_var, tmp_jobid, &jobid_len);

        if (rc) {
                if (rc == -EOVERFLOW) {
                        /* For the PBS_JOBID and LOADL_STEP_ID keys (which are
        if (rc) {
                if (rc == -EOVERFLOW) {
                        /* For the PBS_JOBID and LOADL_STEP_ID keys (which are


@@ -172,7 +172,16 @@ int lustre_get_jobid(char *jobid)
                               obd_jobid_var, rc);
                }
        }
                               obd_jobid_var, rc);
                }
        }

-       RETURN(rc);
+
+out:
+       if (rc != 0)
+               RETURN(rc);
+
+       /* Only replace the job ID if it changed. */
+       if (strcmp(jobid, tmp_jobid) != 0)
+               memcpy(jobid, tmp_jobid, jobid_len);
+
+       RETURN(0);

 }
 EXPORT_SYMBOL(lustre_get_jobid);
 
 }
 EXPORT_SYMBOL(lustre_get_jobid);