ocfs2: limit printk when journal is aborted

Once JBD2_ABORT is set, ocfs2_commit_cache will fail in
ocfs2_commit_thread.  Then it will get into a loop with mass logs.  This
will meaninglessly consume a larger number of resource and may lead to
the system hanging.  So limit printk in this case.

[akpm@linux-foundation.org: document the msleep]
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/journal.c

@@ -30,6 +30,7 @@
 #include <linux/kthread.h>
 #include <linux/time.h>
 #include <linux/random.h>
+#include <linux/delay.h>
 
 #include <cluster/masklog.h>
 
@@ -2185,8 +2186,20 @@ static int ocfs2_commit_thread(void *arg)
 					 || kthread_should_stop());
 
 		status = ocfs2_commit_cache(osb);
-		if (status < 0)
-			mlog_errno(status);
+		if (status < 0) {
+			static unsigned long abort_warn_time;
+
+			/* Warn about this once per minute */
+			if (printk_timed_ratelimit(&abort_warn_time, 60*HZ))
+				mlog(ML_ERROR, "status = %d, journal is "
+						"already aborted.\n", status);
+			/*
+			 * After ocfs2_commit_cache() fails, j_num_trans has a
+			 * non-zero value.  Sleep here to avoid a busy-wait
+			 * loop.
+			 */
+			msleep_interruptible(1000);
+		}
 
 		if (kthread_should_stop() && atomic_read(&journal->j_num_trans)){
 			mlog(ML_KTHREAD,