From cd52ed35535ef443f08bf5cd3331d350272885b8 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 20 Mar 2006 13:44:04 -0500 Subject: NFS: Avoid races between writebacks and truncation Currently, there is no serialisation between NFS asynchronous writebacks and truncation at the page level due to the fact that nfs_sync_inode() cannot lock the pages that it is about to write out. This means that it is possible to be flushing out data (and calling something like set_page_writeback()) while the page cache is busy evicting the page. Oops... Use the hooks provided in try_to_release_page() to ensure that dirty pages are always written back to storage before we evict them. Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'fs/nfs/pagelist.c') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index d53857b148e2..d6e076c9dbe1 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -85,6 +85,10 @@ nfs_create_request(struct nfs_open_context *ctx, struct inode *inode, atomic_set(&req->wb_complete, 0); req->wb_index = page->index; page_cache_get(page); + BUG_ON(PagePrivate(page)); + BUG_ON(!PageLocked(page)); + BUG_ON(page->mapping->host != inode); + SetPagePrivate(page); req->wb_offset = offset; req->wb_pgbase = offset; req->wb_bytes = count; @@ -147,8 +151,10 @@ void nfs_clear_page_writeback(struct nfs_page *req) */ void nfs_clear_request(struct nfs_page *req) { - if (req->wb_page) { - page_cache_release(req->wb_page); + struct page *page = req->wb_page; + if (page != NULL) { + ClearPagePrivate(page); + page_cache_release(page); req->wb_page = NULL; } } -- cgit v1.2.3-59-g8ed1b