ext4: Add debugging markers that can be used by systemtap
This debugging markers are designed to debug problems such as the
random filesystem latency problems reported by Arjan.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c
index c37d1e8..5afe437 100644
--- a/fs/ext4/fsync.c
+++ b/fs/ext4/fsync.c
@@ -28,6 +28,7 @@
#include <linux/writeback.h>
#include <linux/jbd2.h>
#include <linux/blkdev.h>
+#include <linux/marker.h>
#include "ext4.h"
#include "ext4_jbd2.h"
@@ -51,6 +52,10 @@
J_ASSERT(ext4_journal_current_handle() == NULL);
+ trace_mark(ext4_sync_file, "dev %s datasync %d ino %ld parent %ld",
+ inode->i_sb->s_id, datasync, inode->i_ino,
+ dentry->d_parent->d_inode->i_ino);
+
/*
* data=writeback:
* The caller's filemap_fdatawrite()/wait will sync the data.
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index dfcd41f..9c02146 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -35,6 +35,7 @@
#include <linux/quotaops.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
+#include <linux/marker.h>
#include <linux/log2.h>
#include <linux/crc16.h>
#include <asm/uaccess.h>
@@ -2951,6 +2952,7 @@
{
tid_t target;
+ trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
sb->s_dirt = 0;
if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
if (wait)