[PATCH 11/11] splice: fold __generic_file_splice_read() into caller

From: Miklos Szeredi
Date: Wed Sep 14 2016 - 04:38:42 EST


generic_file_splice_read() does so little that it makes no sense to keep
__generic_file_splice_read() a separate function.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
fs/splice.c | 70 +++++++++++++++++++++++++------------------------------------
1 file changed, 29 insertions(+), 41 deletions(-)

diff --git a/fs/splice.c b/fs/splice.c
index bee282803ccf..395cbb6b4926 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -260,17 +260,30 @@ void splice_shrink_spd(struct splice_pipe_desc *spd)
kfree(spd->partial);
}

-static int
-__generic_file_splice_read(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags)
+/**
+ * generic_file_splice_read - splice data from file to a pipe
+ * @in: file to splice from
+ * @ppos: position in @in
+ * @pipe: pipe to splice to
+ * @len: number of bytes to splice
+ * @flags: splice modifier flags
+ *
+ * Description:
+ * Will read pages from given file and fill them into a pipe. Can be
+ * used as long as the address_space operations for the source implements
+ * a readpage() hook.
+ *
+ */
+ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags)
{
unsigned int loff, nr_pages, req_pages;
struct page *pages[PIPE_DEF_BUFFERS];
struct partial_page partial[PIPE_DEF_BUFFERS];
struct page *page;
pgoff_t index;
- int error;
+ int ret = 0;
struct splice_pipe_desc spd = {
.pages = pages,
.partial = partial,
@@ -280,6 +293,9 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
.spd_release = spd_release_page,
};

+ if (IS_DAX(in->f_mapping->host))
+ return default_file_splice_read(in, ppos, pipe, len, flags);
+
if (splice_grow_spd(pipe, &spd))
return -ENOMEM;

@@ -288,62 +304,34 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
req_pages = (len + loff + PAGE_SIZE - 1) >> PAGE_SHIFT;
nr_pages = min(req_pages, spd.nr_pages_max);

- error = 0;
while (spd.nr_pages < nr_pages && len) {
- long ret;
+ int nr;

- ret = get_page_for_read(in, loff, len, index, &page);
- if (ret <= 0) {
- error = ret;
+ nr = get_page_for_read(in, loff, len, index, &page);
+ if (nr <= 0) {
+ ret = nr;
break;
}

spd.pages[spd.nr_pages] = page;
spd.partial[spd.nr_pages].offset = loff;
- spd.partial[spd.nr_pages].len = ret;
+ spd.partial[spd.nr_pages].len = nr;
spd.nr_pages++;
index++;
- len -= ret;
+ len -= nr;
loff = 0;
}

in->f_ra.prev_pos = (loff_t)index << PAGE_SHIFT;

if (spd.nr_pages)
- error = splice_to_pipe(pipe, &spd);
-
- splice_shrink_spd(&spd);
- return error;
-}
-
-/**
- * generic_file_splice_read - splice data from file to a pipe
- * @in: file to splice from
- * @ppos: position in @in
- * @pipe: pipe to splice to
- * @len: number of bytes to splice
- * @flags: splice modifier flags
- *
- * Description:
- * Will read pages from given file and fill them into a pipe. Can be
- * used as long as the address_space operations for the source implements
- * a readpage() hook.
- *
- */
-ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
- struct pipe_inode_info *pipe, size_t len,
- unsigned int flags)
-{
- int ret;
-
- if (IS_DAX(in->f_mapping->host))
- return default_file_splice_read(in, ppos, pipe, len, flags);
+ ret = splice_to_pipe(pipe, &spd);

- ret = __generic_file_splice_read(in, ppos, pipe, len, flags);
if (ret > 0) {
*ppos += ret;
file_accessed(in);
}
+ splice_shrink_spd(&spd);

return ret;
}
--
2.5.5