Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755245AbXLEToH (ORCPT ); Wed, 5 Dec 2007 14:44:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754322AbXLETjf (ORCPT ); Wed, 5 Dec 2007 14:39:35 -0500 Received: from mx1.redhat.com ([66.187.233.31]:34748 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754344AbXLETj0 (ORCPT ); Wed, 5 Dec 2007 14:39:26 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells Subject: [PATCH 09/28] FS-Cache: Release page->private after failed readahead [try #2] To: viro@ftp.linux.org.uk, hch@infradead.org, Trond.Myklebust@netapp.com, sds@tycho.nsa.gov, casey@schaufler-ca.com Cc: linux-kernel@vger.kernel.org, selinux@tycho.nsa.gov, linux-security-module@vger.kernel.org, dhowells@redhat.com Date: Wed, 05 Dec 2007 19:39:04 +0000 Message-ID: <20071205193904.24617.94077.stgit@warthog.procyon.org.uk> In-Reply-To: <20071205193818.24617.79771.stgit@warthog.procyon.org.uk> References: <20071205193818.24617.79771.stgit@warthog.procyon.org.uk> User-Agent: StGIT/0.13 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 Content-Length: 2638 Lines: 81 The attached patch causes read_cache_pages() to release page-private data on a page for which add_to_page_cache() fails or the filler function fails. This permits pages with caching references associated with them to be cleaned up. The invalidatepage() address space op is called (indirectly) to do the honours. Signed-off-by: David Howells --- mm/readahead.c | 39 +++++++++++++++++++++++++++++++++++++-- 1 files changed, 37 insertions(+), 2 deletions(-) diff --git a/mm/readahead.c b/mm/readahead.c index c9c50ca..75aa6b6 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -44,6 +44,41 @@ EXPORT_SYMBOL_GPL(file_ra_state_init); #define list_to_page(head) (list_entry((head)->prev, struct page, lru)) +/* + * see if a page needs releasing upon read_cache_pages() failure + * - the caller of read_cache_pages() may have set PG_private before calling, + * such as the NFS fs marking pages that are cached locally on disk, thus we + * need to give the fs a chance to clean up in the event of an error + */ +static void read_cache_pages_invalidate_page(struct address_space *mapping, + struct page *page) +{ + if (PagePrivate(page)) { + if (TestSetPageLocked(page)) + BUG(); + page->mapping = mapping; + do_invalidatepage(page, 0); + page->mapping = NULL; + unlock_page(page); + } + page_cache_release(page); +} + +/* + * release a list of pages, invalidating them first if need be + */ +static void read_cache_pages_invalidate_pages(struct address_space *mapping, + struct list_head *pages) +{ + struct page *victim; + + while (!list_empty(pages)) { + victim = list_to_page(pages); + list_del(&victim->lru); + read_cache_pages_invalidate_page(mapping, victim); + } +} + /** * read_cache_pages - populate an address space with some pages & start reads against them * @mapping: the address_space @@ -65,14 +100,14 @@ int read_cache_pages(struct address_space *mapping, struct list_head *pages, list_del(&page->lru); if (add_to_page_cache_lru(page, mapping, page->index, GFP_KERNEL)) { - page_cache_release(page); + read_cache_pages_invalidate_page(mapping, page); continue; } page_cache_release(page); ret = filler(data, page); if (unlikely(ret)) { - put_pages_list(pages); + read_cache_pages_invalidate_pages(mapping, pages); break; } task_io_account_read(PAGE_CACHE_SIZE); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/