f2fs: introduce data read/write showing path info

This was used in Android for a long time. Let's upstream it.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 51 insertions, 7 deletions

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 5b89af0f27f0..f08e6208e183 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -4329,17 +4329,39 @@ out:
 static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct inode *inode = file_inode(iocb->ki_filp);
+	const loff_t pos = iocb->ki_pos;
 	ssize_t ret;
 
 	if (!f2fs_is_compress_backend_ready(inode))
 		return -EOPNOTSUPP;
 
-	if (f2fs_should_use_dio(inode, iocb, to))
-		return f2fs_dio_read_iter(iocb, to);
+	if (trace_f2fs_dataread_start_enabled()) {
+		char *p = f2fs_kmalloc(F2FS_I_SB(inode), PATH_MAX, GFP_KERNEL);
+		char *path;
+
+		if (!p)
+			goto skip_read_trace;
+
+		path = dentry_path_raw(file_dentry(iocb->ki_filp), p, PATH_MAX);
+		if (IS_ERR(path)) {
+			kfree(p);
+			goto skip_read_trace;
+		}
 
-	ret = filemap_read(iocb, to, 0);
-	if (ret > 0)
-		f2fs_update_iostat(F2FS_I_SB(inode), APP_BUFFERED_READ_IO, ret);
+		trace_f2fs_dataread_start(inode, pos, iov_iter_count(to),
+					current->pid, path, current->comm);
+		kfree(p);
+	}
+skip_read_trace:
+	if (f2fs_should_use_dio(inode, iocb, to)) {
+		ret = f2fs_dio_read_iter(iocb, to);
+	} else {
+		ret = filemap_read(iocb, to, 0);
+		if (ret > 0)
+			f2fs_update_iostat(F2FS_I_SB(inode), APP_BUFFERED_READ_IO, ret);
+	}
+	if (trace_f2fs_dataread_end_enabled())
+		trace_f2fs_dataread_end(inode, pos, ret);
 	return ret;
 }
 
@@ -4631,14 +4653,36 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	/* Possibly preallocate the blocks for the write. */
 	target_size = iocb->ki_pos + iov_iter_count(from);
 	preallocated = f2fs_preallocate_blocks(iocb, from, dio);
-	if (preallocated < 0)
+	if (preallocated < 0) {
 		ret = preallocated;
-	else
+	} else {
+		if (trace_f2fs_datawrite_start_enabled()) {
+			char *p = f2fs_kmalloc(F2FS_I_SB(inode),
+						PATH_MAX, GFP_KERNEL);
+			char *path;
+
+			if (!p)
+				goto skip_write_trace;
+			path = dentry_path_raw(file_dentry(iocb->ki_filp),
+								p, PATH_MAX);
+			if (IS_ERR(path)) {
+				kfree(p);
+				goto skip_write_trace;
+			}
+			trace_f2fs_datawrite_start(inode, orig_pos, orig_count,
+					current->pid, path, current->comm);
+			kfree(p);
+		}
+skip_write_trace:
 		/* Do the actual write. */
 		ret = dio ?
 			f2fs_dio_write_iter(iocb, from, &may_need_sync):
 			f2fs_buffered_write_iter(iocb, from);
 
+		if (trace_f2fs_datawrite_end_enabled())
+			trace_f2fs_datawrite_end(inode, orig_pos, ret);
+	}
+
 	/* Don't leave any preallocated blocks around past i_size. */
 	if (preallocated && i_size_read(inode) < target_size) {
 		f2fs_down_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);