[PATCH] splice: fix page LRU accounting

[powerpc.git] / fs / splice.c

diff --git a/fs/splice.c b/fs/splice.c
index b0c157d..3318b96 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -78,7 +78,6 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info,
                return 1;
        }
 
-       buf->flags |= PIPE_BUF_FLAG_LRU;
        return 0;
 }
 
@@ -86,8 +85,6 @@ static void page_cache_pipe_buf_release(struct pipe_inode_info *info,
                                        struct pipe_buffer *buf)
 {
        page_cache_release(buf->page);
-       buf->page = NULL;
-       buf->flags &= ~PIPE_BUF_FLAG_LRU;
 }
 
 static int page_cache_pipe_buf_pin(struct pipe_inode_info *info,
@@ -570,22 +567,36 @@ static int pipe_to_file(struct pipe_inode_info *info, struct pipe_buffer *buf,
        if ((sd->flags & SPLICE_F_MOVE) && this_len == PAGE_CACHE_SIZE) {
                /*
                 * If steal succeeds, buf->page is now pruned from the vm
-                * side (LRU and page cache) and we can reuse it. The page
-                * will also be looked on successful return.
+                * side (page cache) and we can reuse it. The page will also
+                * be locked on successful return.
                 */
                if (buf->ops->steal(info, buf))
                        goto find_page;
 
                page = buf->page;
+               page_cache_get(page);
+
+               /*
+                * page must be on the LRU for adding to the pagecache.
+                * Check this without grabbing the zone lock, if it isn't
+                * the do grab the zone lock, recheck, and add if necessary.
+                */
+               if (!PageLRU(page)) {
+                       struct zone *zone = page_zone(page);
+
+                       spin_lock_irq(&zone->lru_lock);
+                       if (!PageLRU(page)) {
+                               SetPageLRU(page);
+                               add_page_to_inactive_list(zone, page);
+                       }
+                       spin_unlock_irq(&zone->lru_lock);
+               }
+
                if (add_to_page_cache(page, mapping, index, gfp_mask)) {
+                       page_cache_release(page);
                        unlock_page(page);
                        goto find_page;
                }
-
-               page_cache_get(page);
-
-               if (!(buf->flags & PIPE_BUF_FLAG_LRU))
-                       lru_cache_add(page);
        } else {
 find_page:
                page = find_lock_page(mapping, index);