LU-9859 libcfs: use wait_event_timeout() in tracefiled().

By using wait_event_timeout() we can make it more clear what is being
waited for, and when the loop terminates.

Signed-off-by: Mr NeilBrown <neilb@suse.de>
Change-Id: I5d015a3cbdbb342a5117e2c328680b3ec13aeb58
Reviewed-on: https://review.whamcloud.com/39293
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/libcfs/libcfs/tracefile.c b/libcfs/libcfs/tracefile.c
index eb89132..7acc5bb 100644 (file)
--- a/libcfs/libcfs/tracefile.c
+++ b/libcfs/libcfs/tracefile.c
@@ -1083,17 +1083,22 @@ static int tracefiled(void *arg)
 
        complete(&tctl->tctl_start);
 
-       while (1) {
-               wait_queue_entry_t __wait;
-
-                pc.pc_want_daemon_pages = 0;
-                collect_pages(&pc);
+       pc.pc_want_daemon_pages = 0;
+
+       while (!last_loop) {
+               wait_event_timeout(tctl->tctl_waitq,
+                                  ({ collect_pages(&pc);
+                                    !list_empty(&pc.pc_pages); }) ||
+                                  atomic_read(&tctl->tctl_shutdown),
+                                  cfs_time_seconds(1));
+               if (atomic_read(&tctl->tctl_shutdown))
+                       last_loop = 1;
                if (list_empty(&pc.pc_pages))
-                        goto end_loop;
+                       continue;
 
-                filp = NULL;
+               filp = NULL;
                down_read(&cfs_tracefile_sem);
-                if (cfs_tracefile[0] != 0) {
+               if (cfs_tracefile[0] != 0) {
                        filp = filp_open(cfs_tracefile,
                                         O_CREAT | O_RDWR | O_LARGEFILE,
                                         0600);
@@ -1105,11 +1110,11 @@ static int tracefiled(void *arg)
                        }
                }
                up_read(&cfs_tracefile_sem);
-                if (filp == NULL) {
-                        put_pages_on_daemon_list(&pc);
+               if (filp == NULL) {
+                       put_pages_on_daemon_list(&pc);
                        __LASSERT(list_empty(&pc.pc_pages));
-                        goto end_loop;
-                }
+                       continue;
+               }
 
                list_for_each_entry_safe(tage, tmp, &pc.pc_pages, linkage) {
                        struct dentry *de = file_dentry(filp);
@@ -1132,12 +1137,12 @@ static int tracefiled(void *arg)
                                __LASSERT(list_empty(&pc.pc_pages));
                                break;
                        }
-                }
+               }
 
                filp_close(filp, NULL);
-                put_pages_on_daemon_list(&pc);
+               put_pages_on_daemon_list(&pc);
                if (!list_empty(&pc.pc_pages)) {
-                        int i;
+                       int i;
 
                        pr_alert("Lustre: trace pages aren't empty\n");
                        pr_err("Lustre: total cpus(%d): ", num_possible_cpus());
@@ -1156,22 +1161,9 @@ static int tracefiled(void *arg)
                        pr_err("Lustre: There are %d pages unwritten\n", i);
                }
                __LASSERT(list_empty(&pc.pc_pages));
-end_loop:
-               if (atomic_read(&tctl->tctl_shutdown)) {
-                       if (last_loop == 0) {
-                               last_loop = 1;
-                               continue;
-                       } else {
-                               break;
-                       }
-               }
-               init_wait(&__wait);
-               add_wait_queue(&tctl->tctl_waitq, &__wait);
-               schedule_timeout_interruptible(cfs_time_seconds(1));
-               remove_wait_queue(&tctl->tctl_waitq, &__wait);
-        }
+       }
        complete(&tctl->tctl_stop);
-        return 0;
+       return 0;
 }
 
 int cfs_trace_start_thread(void)