From a08a166fe77d9f9ad88ed6d06b97e73453661f89 Mon Sep 17 00:00:00 2001
From: Fengguang Wu <wfg@mail.ustc.edu.cn>
Date: Thu, 19 Jul 2007 01:48:03 -0700
Subject: [PATCH] readahead: convert splice invocations
Convert splice reads to use on-demand readahead.
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Cc: Steven Pratt <slpratt@austin.ibm.com>
Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/splice.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/fs/splice.c b/fs/splice.c
index 53fc2082a4681..722449f7d5d6b 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -286,12 +286,6 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
if (nr_pages > PIPE_BUFFERS)
nr_pages = PIPE_BUFFERS;
- /*
- * Don't try to 2nd guess the read-ahead logic, call into
- * page_cache_readahead() like the page cache reads would do.
- */
- page_cache_readahead(mapping, &in->f_ra, in, index, nr_pages);
-
/*
* Lookup the (hopefully) full range of pages we need.
*/
@@ -310,11 +304,8 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
*/
page = find_get_page(mapping, index);
if (!page) {
- /*
- * Make sure the read-ahead engine is notified
- * about this failure.
- */
- handle_ra_miss(mapping, &in->f_ra, index);
+ page_cache_readahead_ondemand(mapping, &in->f_ra, in,
+ NULL, index, nr_pages - spd.nr_pages);
/*
* page didn't exist, allocate one.
@@ -361,6 +352,10 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
this_len = min_t(unsigned long, len, PAGE_CACHE_SIZE - loff);
page = pages[page_nr];
+ if (PageReadahead(page))
+ page_cache_readahead_ondemand(mapping, &in->f_ra, in,
+ page, index, nr_pages - page_nr);
+
/*
* If the page isn't uptodate, we may need to start io on it
*/
@@ -453,6 +448,7 @@ __generic_file_splice_read(struct file *in, loff_t *ppos,
*/
while (page_nr < nr_pages)
page_cache_release(pages[page_nr++]);
+ in->f_ra.prev_index = index;
if (spd.nr_pages)
return splice_to_pipe(pipe, &spd);
--
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