From bbdfc2f70610bebb841d0874dc901c648308e43a Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 6 Nov 2007 23:29:47 -0800
Subject: [PATCH] [SPLICE]: Don't assume regular pages in splice_to_pipe()

Allow caller to pass in a release function, there might be
other resources that need releasing as well. Needed for
network receive.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 fs/splice.c            | 9 ++++++++-
 include/linux/splice.h | 1 +
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/splice.c b/fs/splice.c
index 56b802bfbfa..0a0b79b01d0 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -254,11 +254,16 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
 	}
 
 	while (page_nr < spd_pages)
-		page_cache_release(spd->pages[page_nr++]);
+		spd->spd_release(spd, page_nr++);
 
 	return ret;
 }
 
+static void spd_release_page(struct splice_pipe_desc *spd, unsigned int i)
+{
+	page_cache_release(spd->pages[i]);
+}
+
 static int
 __generic_file_splice_read(struct file *in, loff_t *ppos,
 			   struct pipe_inode_info *pipe, size_t len,
@@ -277,6 +282,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
 		.partial = partial,
 		.flags = flags,
 		.ops = &page_cache_pipe_buf_ops,
+		.spd_release = spd_release_page,
 	};
 
 	index = *ppos >> PAGE_CACHE_SHIFT;
@@ -1432,6 +1438,7 @@ static long vmsplice_to_pipe(struct file *file, const struct iovec __user *iov,
 		.partial = partial,
 		.flags = flags,
 		.ops = &user_page_pipe_buf_ops,
+		.spd_release = spd_release_page,
 	};
 
 	pipe = pipe_info(file->f_path.dentry->d_inode);
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 33e447f98a5..528dcb93c2f 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -53,6 +53,7 @@ struct splice_pipe_desc {
 	int nr_pages;			/* number of pages in map */
 	unsigned int flags;		/* splice flags */
 	const struct pipe_buf_operations *ops;/* ops associated with output pipe */
+	void (*spd_release)(struct splice_pipe_desc *, unsigned int);
 };
 
 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
-- 
2.41.3