[PATCH] splice: be smarter about calling do_page_cache_readahead()
We don't want to call into the read-ahead logic unless we are at the
start of a page, _or_ we have multiple pages to read.
Signed-off-by: Jens Axboe <axboe@suse.de>
diff --git a/fs/splice.c b/fs/splice.c
index 50c43a1..9bfd6af 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -250,9 +250,12 @@
nr_pages = PIPE_BUFFERS;
/*
- * initiate read-ahead on this page range
+ * initiate read-ahead on this page range. however, don't call into
+ * read-ahead if this is a non-zero offset (we are likely doing small
+ * chunk splice and the page is already there) for a single page.
*/
- do_page_cache_readahead(mapping, in, index, nr_pages);
+ if (!offset || nr_pages > 1)
+ do_page_cache_readahead(mapping, in, index, nr_pages);
/*
* now fill in the holes