From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753159Ab2KPRKS (ORCPT ); Fri, 16 Nov 2012 12:10:18 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:7946 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753006Ab2KPRKP (ORCPT ); Fri, 16 Nov 2012 12:10:15 -0500 Subject: [PATCH 10/14] fuse: fuse_writepage_locked() should wait on writeback To: miklos@szeredi.hu From: Maxim Patlasov Cc: dev@parallels.com, fuse-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, jbottomley@parallels.com, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, xemul@openvz.org Date: Fri, 16 Nov 2012 21:09:55 +0400 Message-ID: <20121116170944.3196.66478.stgit@maximpc.sw.ru> In-Reply-To: <20121116170123.3196.93431.stgit@maximpc.sw.ru> References: <20121116170123.3196.93431.stgit@maximpc.sw.ru> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org fuse_writepage_locked() should never submit new i/o for given page->index if there is another one 'in progress' already. In most cases it's safe to wait on page writeback. But if it was called due to memory shortage (WB_SYNC_NONE), we should redirty page rather than blocking caller. Signed-off-by: Maxim Patlasov --- fs/fuse/file.c | 18 +++++++++++++++--- 1 files changed, 15 insertions(+), 3 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 3274708..4e4f6fd 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1370,7 +1370,8 @@ static struct fuse_file *fuse_write_file(struct fuse_conn *fc, return ff; } -static int fuse_writepage_locked(struct page *page) +static int fuse_writepage_locked(struct page *page, + struct writeback_control *wbc) { struct address_space *mapping = page->mapping; struct inode *inode = mapping->host; @@ -1379,6 +1380,14 @@ static int fuse_writepage_locked(struct page *page) struct fuse_req *req; struct page *tmp_page; + if (fuse_page_is_writeback(inode, page->index)) { + if (wbc->sync_mode != WB_SYNC_ALL) { + redirty_page_for_writepage(wbc, page); + return 0; + } + fuse_wait_on_page_writeback(inode, page->index); + } + set_page_writeback(page); req = fuse_request_alloc_nofs(); @@ -1424,7 +1433,7 @@ static int fuse_writepage(struct page *page, struct writeback_control *wbc) { int err; - err = fuse_writepage_locked(page); + err = fuse_writepage_locked(page, wbc); unlock_page(page); return err; @@ -1678,7 +1687,10 @@ static int fuse_launder_page(struct page *page) int err = 0; if (clear_page_dirty_for_io(page)) { struct inode *inode = page->mapping->host; - err = fuse_writepage_locked(page); + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + }; + err = fuse_writepage_locked(page, &wbc); if (!err) fuse_wait_on_page_writeback(inode, page->index); }