From ef6a3c63112e865d632ff7c478ba7c7160cad0d1 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Tue, 22 Mar 2011 16:30:52 -0700 Subject: mm: add replace_page_cache_page() function This function basically does: remove_from_page_cache(old); page_cache_release(old); add_to_page_cache_locked(new); Except it does this atomically, so there's no possibility for the "add" to fail because of a race. If memory cgroups are enabled, then the memory cgroup charge is also moved from the old page to the new. This function is currently used by fuse to move pages into the page cache on read, instead of copying the page contents. [minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()] Signed-off-by: Miklos Szeredi Acked-by: Rik van Riel Acked-by: KAMEZAWA Hiroyuki Cc: Mel Gorman Signed-off-by: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dev.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index 213d3cf4f5e9..640fc229df10 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -737,14 +737,12 @@ static int fuse_try_move_page(struct fuse_copy_state *cs, struct page **pagep) if (WARN_ON(PageMlocked(oldpage))) goto out_fallback_unlock; - remove_from_page_cache(oldpage); - page_cache_release(oldpage); - - err = add_to_page_cache_locked(newpage, mapping, index, GFP_KERNEL); + err = replace_page_cache_page(oldpage, newpage, GFP_KERNEL); if (err) { - printk(KERN_WARNING "fuse_try_move_page: failed to add page"); - goto out_fallback_unlock; + unlock_page(newpage); + return err; } + page_cache_get(newpage); if (!(buf->flags & PIPE_BUF_FLAG_LRU)) -- cgit v1.2.3