From patchwork Thu Mar 28 16:34:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13609006 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D584A136E01 for ; Thu, 28 Mar 2024 16:36:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711643813; cv=none; b=q4nPS6Hd4KhL4uKpQxC09RBtyhpd2ifCa1ERKsYoOeNwHiIT6hZTDs0fcJg3mJev1q5VJlra6ly5duCedY37kS6fDT3A/sTcjAsl87YQ4xKNGOvkmfme1HhHOw0gsqhMkcdpQjaspJoJq6d0gP2EpE1AAmnQNVslDATrypARNvY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711643813; c=relaxed/simple; bh=WnncWnxxgP9sLHcDQXDUZGQwIjBqKphDXHD0PeS3QKQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=p+WTSim7qJ7q7T1eASet7sKQDOGedT5h/ISLpHg9c5FnoGrAWAT6zTlbJhLt7STiDaQMIXja16VoCY5kFxwneq1uZTnjRQ+bC0thJP9tE98mCQQ7GTkPBJ3GuGit0T4CMsuf57FeC7w6tj86zggCNJrs/lbOPY4jgd0NcRcrbZg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=aya5IaYL; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aya5IaYL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1711643810; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lykrnbha/6S87zBZnY0wz/f7lqvJK6Se2csvQWUZWMQ=; b=aya5IaYLxJnQqfrXaCtDWXSWJ7vAxkhUlnkBI+QPkyYySQMVUeDNet4IFU40DTjG6ONizf bjI4vGqgmYKJl81Z9XwPvunEtxPc9RIRh/klgJiIznIjDpLAoZ4lbUk2OUlgGiFX4iEPOi TMfU2UpyJZngarhySNgcv6cy9rKNiio= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-616-zNPlVeWXO8uUH_TirPk-BA-1; Thu, 28 Mar 2024 12:36:44 -0400 X-MC-Unique: zNPlVeWXO8uUH_TirPk-BA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 37CBF1C05147; Thu, 28 Mar 2024 16:36:43 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.146]) by smtp.corp.redhat.com (Postfix) with ESMTP id F2813C37A87; Thu, 28 Mar 2024 16:36:38 +0000 (UTC) From: David Howells To: Christian Brauner , Jeff Layton , Gao Xiang , Dominique Martinet Cc: David Howells , Matthew Wilcox , Steve French , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Eric Van Hensbergen , Ilya Dryomov , netfs@lists.linux.dev, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-cifs@vger.kernel.org, linux-nfs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs@lists.linux.dev, linux-erofs@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Miklos Szeredi , Trond Myklebust , Christoph Hellwig , Andrew Morton , Alexander Viro , Christian Brauner , devel@lists.orangefs.org Subject: [PATCH 09/26] mm: Provide a means of invalidation without using launder_folio Date: Thu, 28 Mar 2024 16:34:01 +0000 Message-ID: <20240328163424.2781320-10-dhowells@redhat.com> In-Reply-To: <20240328163424.2781320-1-dhowells@redhat.com> References: <20240328163424.2781320-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.8 Implement a replacement for launder_folio. The key feature of invalidate_inode_pages2() is that it locks each folio individually, unmaps it to prevent mmap'd accesses interfering and calls the ->launder_folio() address_space op to flush it. This has problems: firstly, each folio is written individually as one or more small writes; secondly, adjacent folios cannot be added so easily into the laundry; thirdly, it's yet another op to implement. Instead, use the invalidate lock to cause anyone wanting to add a folio to the inode to wait, then unmap all the folios if we have mmaps, then, conditionally, use ->writepages() to flush any dirty data back and then discard all pages. The invalidate lock prevents ->read_iter(), ->write_iter() and faulting through mmap all from adding pages for the duration. Signed-off-by: David Howells cc: Matthew Wilcox cc: Miklos Szeredi cc: Trond Myklebust cc: Christoph Hellwig cc: Andrew Morton cc: Alexander Viro cc: Christian Brauner cc: Jeff Layton cc: linux-mm@kvack.org cc: linux-fsdevel@vger.kernel.org cc: netfs@lists.linux.dev cc: v9fs@lists.linux.dev cc: linux-afs@lists.infradead.org cc: ceph-devel@vger.kernel.org cc: linux-cifs@vger.kernel.org cc: linux-nfs@vger.kernel.org cc: devel@lists.orangefs.org --- include/linux/pagemap.h | 1 + mm/filemap.c | 46 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+) diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 2df35e65557d..4eb3d4177a53 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -40,6 +40,7 @@ int filemap_fdatawait_keep_errors(struct address_space *mapping); int filemap_fdatawait_range(struct address_space *, loff_t lstart, loff_t lend); int filemap_fdatawait_range_keep_errors(struct address_space *mapping, loff_t start_byte, loff_t end_byte); +int filemap_invalidate_inode(struct inode *inode, bool flush); static inline int filemap_fdatawait(struct address_space *mapping) { diff --git a/mm/filemap.c b/mm/filemap.c index 25983f0f96e3..087f685107a5 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -4134,6 +4134,52 @@ bool filemap_release_folio(struct folio *folio, gfp_t gfp) } EXPORT_SYMBOL(filemap_release_folio); +/** + * filemap_invalidate_inode - Invalidate/forcibly write back an inode's pagecache + * @inode: The inode to flush + * @flush: Set to write back rather than simply invalidate. + * + * Invalidate all the folios on an inode, possibly writing them back first. + * Whilst the operation is undertaken, the invalidate lock is held to prevent + * new folios from being installed. + */ +int filemap_invalidate_inode(struct inode *inode, bool flush) +{ + struct address_space *mapping = inode->i_mapping; + + if (!mapping || !mapping->nrpages) + goto out; + + /* Prevent new folios from being added to the inode. */ + filemap_invalidate_lock(mapping); + + if (!mapping->nrpages) + goto unlock; + + unmap_mapping_pages(mapping, 0, ULONG_MAX, false); + + /* Write back the data if we're asked to. */ + if (flush) { + struct writeback_control wbc = { + .sync_mode = WB_SYNC_ALL, + .nr_to_write = LONG_MAX, + .range_start = 0, + .range_end = LLONG_MAX, + }; + + filemap_fdatawrite_wbc(mapping, &wbc); + } + + /* Wait for writeback to complete on all folios and discard. */ + truncate_inode_pages_range(mapping, 0, LLONG_MAX); + +unlock: + filemap_invalidate_unlock(mapping); +out: + return filemap_check_errors(mapping); +} +EXPORT_SYMBOL(filemap_invalidate_inode); + #ifdef CONFIG_CACHESTAT_SYSCALL /** * filemap_cachestat() - compute the page cache statistics of a mapping