From patchwork Wed Dec 13 15:23:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13491342 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GWas0VzM" Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71BD5D54 for ; Wed, 13 Dec 2023 07:25:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702481101; 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=PLa1FYhVvXUSTtOx9SWX7UrxEmhpA+746l5QW31q7Os=; b=GWas0VzMN/uK6EEIlxvX55cnrOZYVjUGMdRfxlwI5j428YI6dLodX1eVrbHS46Y3hqhzr+ BaBvI4RasAmwUXyFXxQXh6mSSp4csTUKKOLrduCviVuGVWTHJT/Y32Jv+grmLVM6N9Nyjg 1CtyITbv0WohGquXPMKdRfHmkCARdYY= 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-471-JqQgBQZUPnO1fkGTGEhnIw-1; Wed, 13 Dec 2023 10:24:56 -0500 X-MC-Unique: JqQgBQZUPnO1fkGTGEhnIw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (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 952AD280CFA0; Wed, 13 Dec 2023 15:24:54 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.2]) by smtp.corp.redhat.com (Postfix) with ESMTP id BD2A340C6EBA; Wed, 13 Dec 2023 15:24:51 +0000 (UTC) From: David Howells To: Jeff Layton , Steve French Cc: David Howells , Matthew Wilcox , Marc Dionne , Paulo Alcantara , Shyam Prasad N , Tom Talpey , Dominique Martinet , Eric Van Hensbergen , Ilya Dryomov , Christian Brauner , 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-fsdevel@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 14/39] netfs: Provide tools to create a buffer in an xarray Date: Wed, 13 Dec 2023 15:23:24 +0000 Message-ID: <20231213152350.431591-15-dhowells@redhat.com> In-Reply-To: <20231213152350.431591-1-dhowells@redhat.com> References: <20231213152350.431591-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-nfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.2 Provide tools to create a buffer in an xarray, with a function to add new folios with a mark. This will be used to create bounce buffer and can be used more easily to create a list of folios the span of which would require more than a page's worth of bio_vec structs. Signed-off-by: David Howells cc: Jeff Layton cc: linux-cachefs@redhat.com cc: linux-fsdevel@vger.kernel.org cc: linux-mm@kvack.org --- fs/netfs/internal.h | 13 +++++++ fs/netfs/misc.c | 81 +++++++++++++++++++++++++++++++++++++++++++ include/linux/netfs.h | 4 +++ 3 files changed, 98 insertions(+) diff --git a/fs/netfs/internal.h b/fs/netfs/internal.h index 937d9a22f178..20eb1fd6986e 100644 --- a/fs/netfs/internal.h +++ b/fs/netfs/internal.h @@ -56,6 +56,19 @@ static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {} static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {} #endif +/* + * misc.c + */ +#define NETFS_FLAG_PUT_MARK BIT(0) +#define NETFS_FLAG_PAGECACHE_MARK BIT(1) +int netfs_xa_store_and_mark(struct xarray *xa, unsigned long index, + struct folio *folio, unsigned int flags, + gfp_t gfp_mask); +int netfs_add_folios_to_buffer(struct xarray *buffer, + struct address_space *mapping, + pgoff_t index, pgoff_t to, gfp_t gfp_mask); +void netfs_clear_buffer(struct xarray *buffer); + /* * objects.c */ diff --git a/fs/netfs/misc.c b/fs/netfs/misc.c index d946d85764de..96014c3d1683 100644 --- a/fs/netfs/misc.c +++ b/fs/netfs/misc.c @@ -8,6 +8,87 @@ #include #include "internal.h" +/* + * Attach a folio to the buffer and maybe set marks on it to say that we need + * to put the folio later and twiddle the pagecache flags. + */ +int netfs_xa_store_and_mark(struct xarray *xa, unsigned long index, + struct folio *folio, unsigned int flags, + gfp_t gfp_mask) +{ + XA_STATE_ORDER(xas, xa, index, folio_order(folio)); + +retry: + xas_lock(&xas); + for (;;) { + xas_store(&xas, folio); + if (!xas_error(&xas)) + break; + xas_unlock(&xas); + if (!xas_nomem(&xas, gfp_mask)) + return xas_error(&xas); + goto retry; + } + + if (flags & NETFS_FLAG_PUT_MARK) + xas_set_mark(&xas, NETFS_BUF_PUT_MARK); + if (flags & NETFS_FLAG_PAGECACHE_MARK) + xas_set_mark(&xas, NETFS_BUF_PAGECACHE_MARK); + xas_unlock(&xas); + return xas_error(&xas); +} + +/* + * Create the specified range of folios in the buffer attached to the read + * request. The folios are marked with NETFS_BUF_PUT_MARK so that we know that + * these need freeing later. + */ +int netfs_add_folios_to_buffer(struct xarray *buffer, + struct address_space *mapping, + pgoff_t index, pgoff_t to, gfp_t gfp_mask) +{ + struct folio *folio; + int ret; + + if (to + 1 == index) /* Page range is inclusive */ + return 0; + + do { + /* TODO: Figure out what order folio can be allocated here */ + folio = filemap_alloc_folio(readahead_gfp_mask(mapping), 0); + if (!folio) + return -ENOMEM; + folio->index = index; + ret = netfs_xa_store_and_mark(buffer, index, folio, + NETFS_FLAG_PUT_MARK, gfp_mask); + if (ret < 0) { + folio_put(folio); + return ret; + } + + index += folio_nr_pages(folio); + } while (index <= to && index != 0); + + return 0; +} + +/* + * Clear an xarray buffer, putting a ref on the folios that have + * NETFS_BUF_PUT_MARK set. + */ +void netfs_clear_buffer(struct xarray *buffer) +{ + struct folio *folio; + XA_STATE(xas, buffer, 0); + + rcu_read_lock(); + xas_for_each_marked(&xas, folio, ULONG_MAX, NETFS_BUF_PUT_MARK) { + folio_put(folio); + } + rcu_read_unlock(); + xa_destroy(buffer); +} + /** * netfs_dirty_folio - Mark folio dirty and pin a cache object for writeback * @mapping: The mapping the folio belongs to. diff --git a/include/linux/netfs.h b/include/linux/netfs.h index bbb33ccbf719..c05150f51beb 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -109,6 +109,10 @@ static inline int wait_on_page_fscache_killable(struct page *page) return folio_wait_private_2_killable(page_folio(page)); } +/* Marks used on xarray-based buffers */ +#define NETFS_BUF_PUT_MARK XA_MARK_0 /* - Page needs putting */ +#define NETFS_BUF_PAGECACHE_MARK XA_MARK_1 /* - Page needs wb/dirty flag wrangling */ + enum netfs_io_source { NETFS_FILL_WITH_ZEROES, NETFS_DOWNLOAD_FROM_SERVER,