[PATCH-v2 4/5] vfs: add lazytime tracepoints for better debugging

Theodore Ts'o
2014-11-22T16:54:39Z

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/fs-writeback.c | 5 ++++-
fs/inode.c | 5 +++++
include/trace/events/fs.h | 56 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 65 insertions(+), 1 deletion(-)
create mode 100644 include/trace/events/fs.h

diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index eb04277..cab2d6d 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -27,6 +27,7 @@
#include <linux/backing-dev.h>
#include <linux/tracepoint.h>
#include <linux/device.h>
+#include <trace/events/fs.h>
#include "internal.h"

/*
@@ -1304,8 +1305,10 @@ static void flush_sb_dirty_time(struct super_block *sb)
iput(old_inode);
old_inode = inode;

- if (dirty_time)
+ if (dirty_time) {
+ trace_fs_lazytime_flush(inode);
mark_inode_dirty(inode);
+ }
cond_resched();
spin_lock(&inode_sb_list_lock);
}
diff --git a/fs/inode.c b/fs/inode.c
index 0d939a8..5a9a7b0 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -20,6 +20,9 @@
#include <linux/list_lru.h>
#include "internal.h"

+#define CREATE_TRACE_POINTS
+#include <trace/events/fs.h>
+
/*
* Inode locking rules:
*
@@ -544,6 +547,7 @@ static void evict(struct inode *inode)
mark_inode_dirty(inode);
inode->i_sb->s_op->write_inode(inode, &wbc);
}
+ trace_fs_lazytime_evict(inode);
}

if (!list_empty(&inode->i_wb_list))
@@ -1546,6 +1550,7 @@ static int update_time(struct inode *inode, struct timespec *time, int flags)
inode->i_state |= I_DIRTY_TIME;
spin_unlock(&inode->i_lock);
inode->i_ts_dirty_day = days_since_boot;
+ trace_fs_lazytime_defer(inode);
return 0;
}
inode->i_ts_dirty_day = 0;
diff --git a/include/trace/events/fs.h b/include/trace/events/fs.h
new file mode 100644
index 0000000..ca06d5c
--- /dev/null
+++ b/include/trace/events/fs.h
@@ -0,0 +1,56 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fs
+
+#if !defined(_TRACE_FS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FS_H
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(fs__inode,
+ TP_PROTO(struct inode *inode),
+
+ TP_ARGS(inode),
+
+ TP_STRUCT__entry(
+ __field( dev_t, dev )
+ __field( ino_t, ino )
+ __field( uid_t, uid )
+ __field( gid_t, gid )
+ __field( __u16, mode )
+ ),
+
+ TP_fast_assign(
+ __entry->dev = inode->i_sb->s_dev;
+ __entry->ino = inode->i_ino;
+ __entry->uid = i_uid_read(inode);
+ __entry->gid = i_gid_read(inode);
+ __entry->mode = inode->i_mode;
+ ),
+
+ TP_printk("dev %d,%d ino %lu mode 0%o uid %u gid %u",
+ MAJOR(__entry->dev), MINOR(__entry->dev),
+ (unsigned long) __entry->ino, __entry->mode,
+ __entry->uid, __entry->gid)
+);
+
+DEFINE_EVENT(fs__inode, fs_lazytime_defer,
+ TP_PROTO(struct inode *inode),
+
+ TP_ARGS(inode)
+);
+
+DEFINE_EVENT(fs__inode, fs_lazytime_evict,
+ TP_PROTO(struct inode *inode),
+
+ TP_ARGS(inode)
+);
+
+DEFINE_EVENT(fs__inode, fs_lazytime_flush,
+ TP_PROTO(struct inode *inode),
+
+ TP_ARGS(inode)
+);
+#endif /* _TRACE_FS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>