[PATCH 1/2] mm: filemap: Remove redundant code in do_read_cache_page

[Mel Gorman]

do_read_cache_page and __read_cache_page duplicates page filler code
when filling the page for the first time. This patch simply removes the
duplicate logic.

Signed-off-by: Mel Gorman <mgor...@techsingularity.net>
---
 mm/filemap.c | 43 ++++++++++++-------------------------------
 1 file changed, 12 insertions(+), 31 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index bc943867d68c..aa38593d0cd5 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2283,7 +2283,7 @@ static struct page *wait_on_page_read(struct page *page)
        return page;
 }
 
-static struct page *__read_cache_page(struct address_space *mapping,
+static struct page *do_read_cache_page(struct address_space *mapping,
                                pgoff_t index,
                                int (*filler)(void *, struct page *),
                                void *data,
@@ -2305,31 +2305,19 @@ static struct page *__read_cache_page(struct 
address_space *mapping,
                        /* Presumably ENOMEM for radix tree node */
                        return ERR_PTR(err);
                }
+
+filler:
                err = filler(data, page);
                if (err < 0) {
                        page_cache_release(page);
-                       page = ERR_PTR(err);
-               } else {
-                       page = wait_on_page_read(page);
+                       return ERR_PTR(err);
                }
-       }
-       return page;
-}
-
-static struct page *do_read_cache_page(struct address_space *mapping,
-                               pgoff_t index,
-                               int (*filler)(void *, struct page *),
-                               void *data,
-                               gfp_t gfp)
-
-{
-       struct page *page;
-       int err;
 
-retry:
-       page = __read_cache_page(mapping, index, filler, data, gfp);
-       if (IS_ERR(page))
-               return page;
+               page = wait_on_page_read(page);
+               if (IS_ERR(page))
+                       return page;
+               goto out;
+       }
        if (PageUptodate(page))
                goto out;
 
@@ -2337,21 +2325,14 @@ static struct page *do_read_cache_page(struct 
address_space *mapping,
        if (!page->mapping) {
                unlock_page(page);
                page_cache_release(page);
-               goto retry;
+               goto repeat;
        }
        if (PageUptodate(page)) {
                unlock_page(page);
                goto out;
        }
-       err = filler(data, page);
-       if (err < 0) {
-               page_cache_release(page);
-               return ERR_PTR(err);
-       } else {
-               page = wait_on_page_read(page);
-               if (IS_ERR(page))
-                       return page;
-       }
+       goto filler;
+
 out:
        mark_page_accessed(page);
        return page;
-- 
2.6.4