readahead: combine file_ra_state.prev_index/prev_offset into prev_pos
[linux-2.6.git] / mm / filemap.c
index 5dc18d7..bbcca45 100644 (file)
@@ -879,8 +879,8 @@ void do_generic_mapping_read(struct address_space *mapping,
        cached_page = NULL;
        index = *ppos >> PAGE_CACHE_SHIFT;
        next_index = index;
-       prev_index = ra.prev_index;
-       prev_offset = ra.prev_offset;
+       prev_index = ra.prev_pos >> PAGE_CACHE_SHIFT;
+       prev_offset = ra.prev_pos & (PAGE_CACHE_SIZE-1);
        last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
        offset = *ppos & ~PAGE_CACHE_MASK;
 
@@ -966,7 +966,6 @@ page_ok:
                index += offset >> PAGE_CACHE_SHIFT;
                offset &= ~PAGE_CACHE_MASK;
                prev_offset = offset;
-               ra.prev_offset = offset;
 
                page_cache_release(page);
                if (ret == nr && desc->count)
@@ -1056,9 +1055,11 @@ no_cached_page:
 
 out:
        *_ra = ra;
-       _ra->prev_index = prev_index;
+       _ra->prev_pos = prev_index;
+       _ra->prev_pos <<= PAGE_CACHE_SHIFT;
+       _ra->prev_pos |= prev_offset;
 
-       *ppos = ((loff_t) index << PAGE_CACHE_SHIFT) + offset;
+       *ppos = ((loff_t)index << PAGE_CACHE_SHIFT) + offset;
        if (cached_page)
                page_cache_release(cached_page);
        if (filp)
@@ -1396,7 +1397,7 @@ retry_find:
         * Found the page and have a reference on it.
         */
        mark_page_accessed(page);
-       ra->prev_index = page->index;
+       ra->prev_pos = (loff_t)page->index << PAGE_CACHE_SHIFT;
        vmf->page = page;
        return ret | VM_FAULT_LOCKED;