From b2c5db15cfcbca68e8c2b2b13bb4dd3c11c530a0 Mon Sep 17 00:00:00 2001
From: Anuraag Reddy Patllollu <apatllollu@cs.stonybrook.edu>
Date: Wed, 4 Dec 2024 03:16:36 -0500
Subject: [PATCH] wrapfs_file: Add wrapfs wrappers for splice_read and
 splice_write

---
 fs/wrapfs/file.c | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 44 insertions(+), 2 deletions(-)

diff --git a/fs/wrapfs/file.c b/fs/wrapfs/file.c
index 2f7a6ef9d106..a81d97495f10 100644
--- a/fs/wrapfs/file.c
+++ b/fs/wrapfs/file.c
@@ -41,6 +41,48 @@ static ssize_t wrapfs_copy_file_range(struct file *file_in, loff_t pos_in,
 	return err;
 }
 
+static ssize_t wrapfs_generic_file_splice_read(struct file *file, loff_t *pos,
+					       struct pipe_inode_info *info,
+					       size_t len, unsigned int flags)
+{
+	int err;
+	struct file *lower_file;
+	struct dentry *dentry;
+
+	dentry = file->f_path.dentry;
+	lower_file = wrapfs_lower_file(file);
+	err = generic_file_splice_read(lower_file, pos, info, len, flags);
+
+	if (err >= 0) {
+		fsstack_copy_attr_atime(d_inode(dentry),
+					file_inode(lower_file));
+	}
+
+	return err;
+}
+
+static ssize_t wrapfs_iter_file_splice_write(struct pipe_inode_info *info,
+					     struct file *file, loff_t *pos,
+					     size_t len, unsigned int flags)
+{
+	int err;
+	struct file *lower_file;
+	struct dentry *dentry;
+
+	dentry = file->f_path.dentry;
+	lower_file = wrapfs_lower_file(file);
+	err = iter_file_splice_write(info, lower_file, pos, len, flags);
+
+	if (err >= 0) {
+		fsstack_copy_inode_size(d_inode(dentry),
+					file_inode(lower_file));
+		fsstack_copy_attr_times(d_inode(dentry),
+					file_inode(lower_file));
+	}
+
+	return err;
+}
+
 static ssize_t wrapfs_read(struct file *file, char __user *buf,
 			   size_t count, loff_t *ppos)
 {
@@ -414,8 +456,8 @@ const struct file_operations wrapfs_main_fops = {
 	.fasync		= wrapfs_fasync,
 	.read_iter	= wrapfs_read_iter,
 	.write_iter	= wrapfs_write_iter,
-	.splice_read	= generic_file_splice_read,
-	.splice_write	= iter_file_splice_write,
+	.splice_read	= wrapfs_generic_file_splice_read,
+	.splice_write	= wrapfs_iter_file_splice_write,
 };
 
 /* trimmed directory options */
-- 
2.43.0