f2fs: factor the read/write tracing logic into a helper

Factor the logic to log a path for reads and writs into a helper
shared between the read_iter and write_iter methods.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -4341,6 +4341,27 @@ static ssize_t f2fs_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	return ret;
 }
 
+static void f2fs_trace_rw_file_path(struct kiocb *iocb, size_t count, int rw)
+{
+	struct inode *inode = file_inode(iocb->ki_filp);
+	char *buf, *path;
+
+	buf = f2fs_kmalloc(F2FS_I_SB(inode), PATH_MAX, GFP_KERNEL);
+	if (!buf)
+		return;
+	path = dentry_path_raw(file_dentry(iocb->ki_filp), buf, PATH_MAX);
+	if (IS_ERR(path))
+		goto free_buf;
+	if (rw == WRITE)
+		trace_f2fs_datawrite_start(inode, iocb->ki_pos, count,
+				current->pid, path, current->comm);
+	else
+		trace_f2fs_dataread_start(inode, iocb->ki_pos, count,
+				current->pid, path, current->comm);
+free_buf:
+	kfree(buf);
+}
+
 static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 {
 	struct inode *inode = file_inode(iocb->ki_filp);
@@ -4350,24 +4371,9 @@ static ssize_t f2fs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	if (!f2fs_is_compress_backend_ready(inode))
 		return -EOPNOTSUPP;
 
-	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;
+	if (trace_f2fs_dataread_start_enabled())
+		f2fs_trace_rw_file_path(iocb, iov_iter_count(to), READ);
 
-		path = dentry_path_raw(file_dentry(iocb->ki_filp), p, PATH_MAX);
-		if (IS_ERR(path)) {
-			kfree(p);
-			goto skip_read_trace;
-		}
-
-		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 {
@@ -4673,24 +4679,9 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (preallocated < 0) {
 		ret = preallocated;
 	} 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:
+		if (trace_f2fs_datawrite_start_enabled())
+			f2fs_trace_rw_file_path(iocb, orig_count, WRITE);
+
 		/* Do the actual write. */
 		ret = dio ?
 			f2fs_dio_write_iter(iocb, from, &may_need_sync) :