From 1432873af7ae29d4bb3c56114c05b539d078ca62 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 3 May 2006 10:35:26 +0200 Subject: [PATCH] splice: LRU fixups Nick says that the current construct isn't safe. This goes back to the original, but sets PIPE_BUF_FLAG_LRU on user pages as well as they all seem to be on the LRU in the first place. Signed-off-by: Jens Axboe --- fs/splice.c | 33 +++++++++++---------------------- include/linux/pipe_fs_i.h | 5 +++-- 2 files changed, 14 insertions(+), 24 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index 27f5e3738a7..0b202425b0b 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -78,6 +78,7 @@ static int page_cache_pipe_buf_steal(struct pipe_inode_info *info, return 1; } + buf->flags |= PIPE_BUF_FLAG_LRU; return 0; } @@ -85,6 +86,7 @@ static void page_cache_pipe_buf_release(struct pipe_inode_info *info, struct pipe_buffer *buf) { page_cache_release(buf->page); + buf->flags &= ~PIPE_BUF_FLAG_LRU; } static int page_cache_pipe_buf_pin(struct pipe_inode_info *info, @@ -141,6 +143,7 @@ static int user_page_pipe_buf_steal(struct pipe_inode_info *pipe, if (!(buf->flags & PIPE_BUF_FLAG_GIFT)) return 1; + buf->flags |= PIPE_BUF_FLAG_LRU; return generic_pipe_buf_steal(pipe, buf); } @@ -566,37 +569,23 @@ 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 (page cache) and we can reuse it. The page will also - * be locked on successful return. + * If steal succeeds, buf->page is now pruned from the + * pagecache 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); diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index ba73108cbf8..ea4f7cd7bfd 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -5,8 +5,9 @@ #define PIPE_BUFFERS (16) -#define PIPE_BUF_FLAG_ATOMIC 0x01 /* was atomically mapped */ -#define PIPE_BUF_FLAG_GIFT 0x02 /* page is a gift */ +#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */ +#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */ +#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */ struct pipe_buffer { struct page *page; -- cgit v1.2.3