X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=libcfs%2Flibcfs%2Fdebug.c;h=8669dad85789a2995d05c60519c6e0c73d35d917;hp=b059791572d78b6abd9ed63452bbefc6f0366974;hb=cfba9a1ecc6b20746c289afc8e3c81097e07d8a3;hpb=f6497eb3503b7efff823888ed76422db4e9e078e

diff --git a/libcfs/libcfs/debug.c b/libcfs/libcfs/debug.c
index b059791..8669dad 100644
--- a/libcfs/libcfs/debug.c
+++ b/libcfs/libcfs/debug.c
@@ -69,15 +69,8 @@ static int libcfs_param_debug_mb_set(const char *val,
  * RHEL6 does not support any kind of locking so we have to provide
  * our own
  */
-#if !defined(HAVE_MODULE_PARAM_LOCKING) && !defined(HAVE_KERNEL_PARAM_LOCK)
-	kernel_param_lock(THIS_MODULE);
-#endif
 	if (!*((unsigned int *)kp->arg)) {
 		*((unsigned int *)kp->arg) = num;
-
-#if !defined(HAVE_MODULE_PARAM_LOCKING) && !defined(HAVE_KERNEL_PARAM_LOCK)
-		kernel_param_unlock(THIS_MODULE);
-#endif
 		return 0;
 	}
 
@@ -86,9 +79,6 @@ static int libcfs_param_debug_mb_set(const char *val,
 	if (!rc)
 		*((unsigned int *)kp->arg) = cfs_trace_get_debug_mb();
 
-#if !defined(HAVE_MODULE_PARAM_LOCKING) && !defined(HAVE_KERNEL_PARAM_LOCK)
-	kernel_param_unlock(THIS_MODULE);
-#endif
 	return rc;
 }
 
@@ -259,7 +249,7 @@ MODULE_PARM_DESC(libcfs_panic_on_lbug, "Lustre kernel panic on LBUG");
 atomic_t libcfs_kmemory = ATOMIC_INIT(0);
 EXPORT_SYMBOL(libcfs_kmemory);
 
-static wait_queue_head_t debug_ctlwq;
+static DECLARE_COMPLETION(debug_complete);
 
 char libcfs_debug_file_path_arr[PATH_MAX] = LIBCFS_DEBUG_FILE_PATH_DEFAULT;
 EXPORT_SYMBOL(libcfs_debug_file_path_arr);
@@ -396,8 +386,7 @@ void libcfs_debug_dumplog_internal(void *arg)
 		snprintf(debug_file_name, sizeof(debug_file_name) - 1,
 			 "%s.%lld.%ld", libcfs_debug_file_path_arr,
 			 (s64)current_time, (uintptr_t)arg);
-		printk(KERN_ALERT "LustreError: dumping log to %s\n",
-		       debug_file_name);
+		pr_alert("LustreError: dumping log to %s\n", debug_file_name);
 		cfs_tracefile_dump_all_pages(debug_file_name);
 		libcfs_run_debug_log_upcall(debug_file_name);
 	}
@@ -407,38 +396,38 @@ void libcfs_debug_dumplog_internal(void *arg)
 static int libcfs_debug_dumplog_thread(void *arg)
 {
 	libcfs_debug_dumplog_internal(arg);
-	wake_up(&debug_ctlwq);
+	complete(&debug_complete);
 	return 0;
 }
 
+static DEFINE_MUTEX(libcfs_debug_dumplog_lock);
+
 void libcfs_debug_dumplog(void)
 {
-	wait_queue_entry_t wait;
 	struct task_struct *dumper;
 
 	ENTRY;
 
-	/*
-	 * we're being careful to ensure that the kernel thread is
-	 * able to set our state to running as it exits before we
-	 * get to schedule()
-	 */
-	init_waitqueue_entry(&wait, current);
-	set_current_state(TASK_INTERRUPTIBLE);
-	add_wait_queue(&debug_ctlwq, &wait);
+	if (mutex_trylock(&libcfs_debug_dumplog_lock) == 0)
+		return;
 
+	/* If a previous call was interrupted, debug_complete->done
+	 * might be elevated, and so we won't actually wait here.
+	 * So we reinit the completion to ensure we wait for
+	 * one thread to complete, though it might not be the one
+	 * we start if there are overlaping thread.
+	 */
+	reinit_completion(&debug_complete);
 	dumper = kthread_run(libcfs_debug_dumplog_thread,
 			     (void *)(long)current_pid(),
 			     "libcfs_debug_dumper");
 	if (IS_ERR(dumper))
-		printk(KERN_ERR "LustreError: cannot start log dump thread:"
-		       " %ld\n", PTR_ERR(dumper));
+		pr_err("LustreError: cannot start log dump thread: rc = %ld\n",
+		       PTR_ERR(dumper));
 	else
-		schedule();
+		wait_for_completion_interruptible(&debug_complete);
 
-	/* be sure to teardown if cfs_create_thread() failed */
-	remove_wait_queue(&debug_ctlwq, &wait);
-	set_current_state(TASK_RUNNING);
+	mutex_unlock(&libcfs_debug_dumplog_lock);
 }
 EXPORT_SYMBOL(libcfs_debug_dumplog);
 
@@ -447,8 +436,6 @@ int libcfs_debug_init(unsigned long bufsize)
 	int rc = 0;
 	unsigned int max = libcfs_debug_mb;
 
-	init_waitqueue_head(&debug_ctlwq);
-
 	if (libcfs_console_max_delay <= 0 || /* not set by user or */
 	    libcfs_console_min_delay <= 0 || /* set to invalid values */
 	    libcfs_console_min_delay >= libcfs_console_max_delay) {