From patchwork Mon Jul 13 16:39:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 11660703 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C69B16C1 for ; Mon, 13 Jul 2020 16:39:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACADD20738 for ; Mon, 13 Jul 2020 16:39:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="goHkOIOY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730472AbgGMQjW (ORCPT ); Mon, 13 Jul 2020 12:39:22 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:36304 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730633AbgGMQjV (ORCPT ); Mon, 13 Jul 2020 12:39:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594658358; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=q/UEZJh6DxJYQ3NJ0rsCIBC20umyEHBIxGnpwbS930w=; b=goHkOIOYNCmpPhcqMekVBwZ8yrEMevIHEPHt2q0nJ5MgRLfki8Y5DX1xN2c6HwidFJimEF GlH7Y3avnNxOh/+bhDVHDegkPemrPBfruaaFkFNtzT1osGvk/7nmnsgV0SlEhdZ+qV/Y7v N94rLMGIUI5R9S2x+0ydD867XyVuFI8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-294-_j0I8sfdN9yYFVLd3GQOIQ-1; Mon, 13 Jul 2020 12:39:15 -0400 X-MC-Unique: _j0I8sfdN9yYFVLd3GQOIQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B9C5980040A; Mon, 13 Jul 2020 16:39:13 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-112-113.rdu2.redhat.com [10.10.112.113]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2FD1B5D9CC; Mon, 13 Jul 2020 16:39:08 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 11/13] afs: Copy local writes to the cache when writing to the server From: David Howells To: Trond Myklebust , Anna Schumaker , Steve French , Alexander Viro , Matthew Wilcox Cc: Jeff Layton , Dave Wysochanski , dhowells@redhat.com, linux-cachefs@redhat.com, linux-afs@lists.infradead.org, linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org, ceph-devel@vger.kernel.org, v9fs-developer@lists.sourceforge.net, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 13 Jul 2020 17:39:07 +0100 Message-ID: <159465834740.1377938.16996503111636748338.stgit@warthog.procyon.org.uk> In-Reply-To: <159465821598.1377938.2046362270225008168.stgit@warthog.procyon.org.uk> References: <159465821598.1377938.2046362270225008168.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.22 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org When writing to the server from afs_writepage() or afs_writepages(), copy the data to the cache object too. Signed-off-by: David Howells --- fs/afs/write.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 128 insertions(+), 4 deletions(-) diff --git a/fs/afs/write.c b/fs/afs/write.c index cb27027c06bb..10c60837775e 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -13,6 +13,9 @@ #include #include "internal.h" +static void afs_write_to_cache(struct afs_vnode *vnode, + pgoff_t start, pgoff_t end, loff_t a, loff_t b); + /* * mark a page as having been made dirty and thus needing writeback */ @@ -427,6 +430,8 @@ static int afs_write_back_from_locked_page(struct address_space *mapping, count = 1; if (test_set_page_writeback(primary_page)) BUG(); + if (TestSetPageFsCache(primary_page)) + BUG(); /* Find all consecutive lockable dirty pages that have contiguous * written regions, stopping when we find a page that is not @@ -475,7 +480,8 @@ static int afs_write_back_from_locked_page(struct address_space *mapping, break; if (!trylock_page(page)) break; - if (!PageDirty(page) || PageWriteback(page)) { + if (!PageDirty(page) || PageWriteback(page) || + PageFsCache(page)) { unlock_page(page); break; } @@ -497,6 +503,8 @@ static int afs_write_back_from_locked_page(struct address_space *mapping, BUG(); if (test_set_page_writeback(page)) BUG(); + if (TestSetPageFsCache(page)) + BUG(); unlock_page(page); put_page(page); } @@ -534,6 +542,11 @@ static int afs_write_back_from_locked_page(struct address_space *mapping, end = i_size; if (pos < i_size) { + /* Speculatively write to the cache. We have to fix this up + * later if the store fails. + */ + afs_write_to_cache(vnode, first, last, pos, end); + iov_iter_mapping(&iter, WRITE, mapping, pos, end - pos); ret = afs_store_data(vnode, &iter, pos, first, last); } else { @@ -592,6 +605,10 @@ int afs_writepage(struct page *page, struct writeback_control *wbc) _enter("{%lx},", page->index); +#ifdef CONFIG_AFS_FSCACHE + wait_on_page_fscache(page); +#endif + ret = afs_write_back_from_locked_page(page->mapping, wbc, page, wbc->range_end >> PAGE_SHIFT); if (ret < 0) { @@ -619,7 +636,7 @@ static int afs_writepages_region(struct address_space *mapping, do { n = find_get_pages_range_tag(mapping, &index, end, - PAGECACHE_TAG_DIRTY, 1, &page); + PAGECACHE_TAG_DIRTY, 1, &page); if (!n) break; @@ -644,10 +661,14 @@ static int afs_writepages_region(struct address_space *mapping, continue; } - if (PageWriteback(page)) { + if (PageWriteback(page) || PageFsCache(page)) { unlock_page(page); - if (wbc->sync_mode != WB_SYNC_NONE) + if (wbc->sync_mode != WB_SYNC_NONE) { wait_on_page_writeback(page); +#ifdef CONFIG_AFS_FSCACHE + wait_on_page_fscache(page); +#endif + } put_page(page); continue; } @@ -868,3 +889,106 @@ int afs_launder_page(struct page *page) ClearPagePrivate(page); return ret; } + +/* + * Clear the PG_fscache flag from a sequence of pages and wake up anyone who's + * waiting. The last page is included in the sequence. + */ +static void afs_clear_fscache_bits(struct address_space *mapping, + pgoff_t start, pgoff_t last) +{ + struct page *page; + + XA_STATE(xas, &mapping->i_pages, start); + + rcu_read_lock(); + xas_for_each(&xas, page, last) { + unlock_page_fscache(page); + } + rcu_read_unlock(); +} + +/* + * Deal with the completion of writing the data to the cache. + */ +static void afs_write_to_cache_done(struct fscache_io_request *_req) +{ + struct afs_read *req = container_of(_req, struct afs_read, cache); + pgoff_t index = req->cache.pos >> PAGE_SHIFT; + pgoff_t last = index + req->cache.nr_pages - 1; + + _enter("%lx,%x,%llx", index, req->cache.nr_pages, req->cache.transferred); + + afs_clear_fscache_bits(req->cache.mapping, index, last); + + if (req->cache.error && req->cache.error != -ENOBUFS) { + struct afs_vnode *vnode = req->vnode; + struct afs_vnode_cache_aux aux = { + .data_version = vnode->status.data_version, + }; + _debug("inval wr %d", req->cache.error); + fscache_invalidate(req->cache.cookie, &aux, + i_size_read(&vnode->vfs_inode), 0); + } +} + +static const struct fscache_io_request_ops afs_write_req_ops = { + .get = afs_req_get, + .put = afs_req_put, +}; + +/* + * Save the write to the cache also. + */ +static void afs_write_to_cache(struct afs_vnode *vnode, + pgoff_t start, pgoff_t last, loff_t a, loff_t b) +{ + struct afs_read *req; + struct iov_iter iter; + + struct fscache_request_shape shape = { + .proposed_start = start, + .proposed_nr_pages = last - start + 1, + .max_io_pages = UINT_MAX, + .i_size = i_size_read(&vnode->vfs_inode), + .for_write = true, + }; + + _enter("%lx,%lx,%llx,%llx", start, last, a, b); + + fscache_shape_request(afs_vnode_cache(vnode), &shape); + if (!(shape.to_be_done & FSCACHE_WRITE_TO_CACHE) || + shape.actual_nr_pages == 0 || + shape.actual_start != start) + goto abandon; + + if (shape.actual_nr_pages < shape.proposed_nr_pages) { + afs_clear_fscache_bits(vnode->vfs_inode.i_mapping, + start + shape.actual_nr_pages, + start + shape.proposed_nr_pages - 1); + last = start + shape.actual_nr_pages - 1; + b = (loff_t)(last + 1) << PAGE_SHIFT; + } + + req = afs_alloc_read(GFP_NOFS); + if (!req) + goto abandon; + + fscache_init_io_request(&req->cache, afs_vnode_cache(vnode), + &afs_write_req_ops); + req->vnode = vnode; + req->cache.pos = round_down(a, shape.dio_block_size); + req->cache.len = round_up(b, shape.dio_block_size) - req->cache.pos; + req->cache.nr_pages = shape.actual_nr_pages; + req->cache.mapping = vnode->vfs_inode.i_mapping; + req->cache.io_done = &afs_write_to_cache_done; + + iov_iter_mapping(&iter, WRITE, req->cache.mapping, + req->cache.pos, req->cache.len); + fscache_write(&req->cache, &iter); + afs_put_read(req); + return; + +abandon: + afs_clear_fscache_bits(vnode->vfs_inode.i_mapping, start, last); +}