[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>

2 files changed, 9 insertions, 1 deletions

diff --git a/fs/splice.c b/fs/splice.c
index 56b802bfbfa4..0a0b79b01d05 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 33e447f98a54..528dcb93c2f2 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 *,