X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=blobdiff_plain;f=libcfs%2Flibcfs%2Fdebug.c;h=8669dad85789a2995d05c60519c6e0c73d35d917;hp=f48d9e5ccded8d18b740cd540acd8258ed5767cd;hb=cfba9a1ecc6b20746c289afc8e3c81097e07d8a3;hpb=9016356a288cb3365ba69c4f287406aa7ebdf97a

diff --git a/libcfs/libcfs/debug.c b/libcfs/libcfs/debug.c
index f48d9e5..8669dad 100644
--- a/libcfs/libcfs/debug.c
+++ b/libcfs/libcfs/debug.c
@@ -400,11 +400,17 @@ static int libcfs_debug_dumplog_thread(void *arg)
 	return 0;
 }
 
+static DEFINE_MUTEX(libcfs_debug_dumplog_lock);
+
 void libcfs_debug_dumplog(void)
 {
 	struct task_struct *dumper;
 
 	ENTRY;
+
+	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
@@ -420,6 +426,8 @@ void libcfs_debug_dumplog(void)
 		       PTR_ERR(dumper));
 	else
 		wait_for_completion_interruptible(&debug_complete);
+
+	mutex_unlock(&libcfs_debug_dumplog_lock);
 }
 EXPORT_SYMBOL(libcfs_debug_dumplog);