mm: filemap: remove redundant code in do_read_cache_page

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

Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/filemap.c b/mm/filemap.c
index da7a35d83de7edc4ed562caa5e1925194f2c7229..deae0b9ad90bb692b0d1eae8ab603abaf4042542 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2303,7 +2303,7 @@ 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,
@@ -2325,31 +2325,19 @@ repeat:
                        /* 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;
 
@@ -2357,21 +2345,14 @@ retry:
        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;