ANDROID: fs: FS tracepoints to track IO.

Adds tracepoints in ext4/f2fs/mpage to track readpages/buffered
write()s. This allows us to track files that are being read/written
to PIDs.

Change-Id: I26bd36f933108927d6903da04d8cb42fd9c3ef3d
Signed-off-by: Mohan Srinivasan <srmohan@google.com>
Git-commit: 32cbbe59538d2dd0b77822cc27ce32ca487c467d
Git-repo: https://android.googlesource.com/kernel/common/
[runminw@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Runmin Wang <runminw@codeaurora.org>

2 files changed, 110 insertions, 0 deletions

diff --git a/include/trace/events/android_fs.h b/include/trace/events/android_fs.h
new file mode 100644
index 000000000000..531da433a7bc
--- /dev/null
+++ b/include/trace/events/android_fs.h
@@ -0,0 +1,31 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM android_fs
+
+#if !defined(_TRACE_ANDROID_FS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ANDROID_FS_H
+
+#include <linux/tracepoint.h>
+#include <trace/events/android_fs_template.h>
+
+DEFINE_EVENT(android_fs_data_start_template, android_fs_dataread_start,
+	TP_PROTO(struct inode *inode, loff_t offset, int bytes,
+		 pid_t pid, char *command),
+	TP_ARGS(inode, offset, bytes, pid, command));
+
+DEFINE_EVENT(android_fs_data_end_template, android_fs_dataread_end,
+	TP_PROTO(struct inode *inode, loff_t offset, int bytes),
+	TP_ARGS(inode, offset, bytes));
+
+DEFINE_EVENT(android_fs_data_start_template, android_fs_datawrite_start,
+	TP_PROTO(struct inode *inode, loff_t offset, int bytes,
+		 pid_t pid, char *command),
+	TP_ARGS(inode, offset, bytes, pid, command));
+
+DEFINE_EVENT(android_fs_data_end_template, android_fs_datawrite_end,
+	TP_PROTO(struct inode *inode, loff_t offset, int bytes),
+	TP_ARGS(inode, offset, bytes));
+
+#endif /* _TRACE_ANDROID_FS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/include/trace/events/android_fs_template.h b/include/trace/events/android_fs_template.h
new file mode 100644
index 000000000000..618988b047c1
--- /dev/null
+++ b/include/trace/events/android_fs_template.h
@@ -0,0 +1,79 @@
+#if !defined(_TRACE_ANDROID_FS_TEMPLATE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_ANDROID_FS_TEMPLATE_H
+
+#include <linux/tracepoint.h>
+
+DECLARE_EVENT_CLASS(android_fs_data_start_template,
+	TP_PROTO(struct inode *inode, loff_t offset, int bytes,
+		 pid_t pid, char *command),
+	TP_ARGS(inode, offset, bytes, pid, command),
+	TP_STRUCT__entry(
+		__array(char, path, MAX_FILTER_STR_VAL);
+		__field(char *, pathname);
+		__field(loff_t,	offset);
+		__field(int,	bytes);
+		__field(loff_t,	i_size);
+		__string(cmdline, command);
+		__field(pid_t,	pid);
+		__field(ino_t,	ino);
+	),
+	TP_fast_assign(
+		{
+			struct dentry *d;
+
+			/*
+			 * Grab a reference to the inode here because
+			 * d_obtain_alias() will either drop the inode
+			 * reference if it locates an existing dentry
+			 * or transfer the reference to the new dentry
+			 * created. In our case, the file is still open,
+			 * so the dentry is guaranteed to exist (connected),
+			 * so d_obtain_alias() drops the reference we
+			 * grabbed here.
+			 */
+			ihold(inode);
+			d = d_obtain_alias(inode);
+			if (!IS_ERR(d)) {
+				__entry->pathname = dentry_path(d,
+							__entry->path,
+							MAX_FILTER_STR_VAL);
+				dput(d);
+			} else
+				__entry->pathname = ERR_PTR(-EINVAL);
+			__entry->offset		= offset;
+			__entry->bytes		= bytes;
+			__entry->i_size		= i_size_read(inode);
+			__assign_str(cmdline, command);
+			__entry->pid		= pid;
+			__entry->ino		= inode->i_ino;
+		}
+	),
+	TP_printk("entry_name %s, offset %llu, bytes %d, cmdline %s,"
+		  " pid %d, i_size %llu, ino %lu",
+		  (IS_ERR(__entry->pathname) ? "ERROR" : __entry->pathname),
+		  __entry->offset, __entry->bytes, __get_str(cmdline),
+		  __entry->pid, __entry->i_size,
+		  (unsigned long) __entry->ino)
+);
+
+DECLARE_EVENT_CLASS(android_fs_data_end_template,
+	TP_PROTO(struct inode *inode, loff_t offset, int bytes),
+	TP_ARGS(inode, offset, bytes),
+	TP_STRUCT__entry(
+		__field(ino_t,	ino);
+		__field(loff_t,	offset);
+		__field(int,	bytes);
+	),
+	TP_fast_assign(
+		{
+			__entry->ino		= inode->i_ino;
+			__entry->offset		= offset;
+			__entry->bytes		= bytes;
+		}
+	),
+	TP_printk("ino %lu, offset %llu, bytes %d",
+		  (unsigned long) __entry->ino,
+		  __entry->offset, __entry->bytes)
+);
+
+#endif /* _TRACE_ANDROID_FS_TEMPLATE_H */