From patchwork Mon Oct 18 15:02:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 12567157 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1597EC433EF for ; Mon, 18 Oct 2021 15:05:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F2D38610A1 for ; Mon, 18 Oct 2021 15:05:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233608AbhJRPHO (ORCPT ); Mon, 18 Oct 2021 11:07:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:33567 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233295AbhJRPEg (ORCPT ); Mon, 18 Oct 2021 11:04:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1634569334; 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=UhcaIo/ficWK/PPSZVzJujLXQ8djt/id9tCh3dUyTWg=; b=ZIFLOUW5bpLsAeDWNfhpvLfroG6jhlqYvvoq1q55Hd81DQft8CaiasO2+QMHssaehPoML1 9dLCymP9dxiHrKWd8zCKXA702rJoZcGQraVwyW0OlfDsgI9UT/4FFccSUzyWWjr+udOScM f6E/zP1kx/yWqHunqz+pCg4G3D29FTI= 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-389-CyF1J0hxMHmBDKdcq6LdIg-1; Mon, 18 Oct 2021 11:02:11 -0400 X-MC-Unique: CyF1J0hxMHmBDKdcq6LdIg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CDD67801FCE; Mon, 18 Oct 2021 15:02:08 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.33.36.19]) by smtp.corp.redhat.com (Postfix) with ESMTP id A731D62A44; Mon, 18 Oct 2021 15:02:02 +0000 (UTC) Organization: Red Hat UK Ltd. 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Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 47/67] cachefiles: Put more information in the xattr attached to the cache file From: David Howells To: linux-cachefs@redhat.com Cc: dhowells@redhat.com, Trond Myklebust , Anna Schumaker , Steve French , Dominique Martinet , Jeff Layton , Matthew Wilcox , Alexander Viro , Omar Sandoval , Linus Torvalds , 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, 18 Oct 2021 16:02:01 +0100 Message-ID: <163456932180.2614702.9793858366854318097.stgit@warthog.procyon.org.uk> In-Reply-To: <163456861570.2614702.14754548462706508617.stgit@warthog.procyon.org.uk> References: <163456861570.2614702.14754548462706508617.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.23 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Put some more information into the xattr attached to a cache file including the size of the object (i_size may get rounded to a block size for DIO purposes), the point after which the server has no data and a content mapping type. Note that the new cache and the old cache will see each other's cache files as being incoherent and discard them. Signed-off-by: David Howells --- fs/cachefiles/interface.c | 1 + fs/cachefiles/internal.h | 11 +++++++++++ fs/cachefiles/xattr.c | 25 +++++++++++++++++++------ 3 files changed, 31 insertions(+), 6 deletions(-) diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index f90f6ddd07a5..751b0fec4591 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -420,6 +420,7 @@ static bool cachefiles_invalidate_cookie(struct fscache_cookie *cookie) old_file = object->file; object->file = new_file; + object->content_info = CACHEFILES_CONTENT_NO_DATA; set_bit(CACHEFILES_OBJECT_USING_TMPFILE, &object->flags); set_bit(FSCACHE_COOKIE_NEEDS_UPDATE, &object->cookie->flags); diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h index a2d2ed2f19eb..1d3e37bca087 100644 --- a/fs/cachefiles/internal.h +++ b/fs/cachefiles/internal.h @@ -31,6 +31,16 @@ extern unsigned cachefiles_debug; #define cachefiles_gfp (__GFP_RECLAIM | __GFP_NORETRY | __GFP_NOMEMALLOC) +enum cachefiles_content { + /* These values are saved on disk */ + CACHEFILES_CONTENT_NO_DATA = 0, /* No content stored */ + CACHEFILES_CONTENT_SINGLE = 1, /* Content is monolithic, all is present */ + CACHEFILES_CONTENT_ALL = 2, /* Content is all present, no map */ + CACHEFILES_CONTENT_BACKFS_MAP = 3, /* Content is piecemeal, mapped through backing fs */ + CACHEFILES_CONTENT_DIRTY = 4, /* Content is dirty (only seen on disk) */ + nr__cachefiles_content +}; + /* * Cached volume representation. */ @@ -59,6 +69,7 @@ struct cachefiles_object { u8 key_hash; /* Hash of object key */ unsigned long flags; #define CACHEFILES_OBJECT_USING_TMPFILE 0 /* Have an unlinked tmpfile */ + enum cachefiles_content content_info:8; /* Info about content presence */ }; extern struct kmem_cache *cachefiles_object_jar; diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c index 50b2a4588946..ba3d050a5174 100644 --- a/fs/cachefiles/xattr.c +++ b/fs/cachefiles/xattr.c @@ -18,8 +18,11 @@ #define CACHEFILES_COOKIE_TYPE_DATA 1 struct cachefiles_xattr { - uint8_t type; - uint8_t data[]; + __be64 object_size; /* Actual size of the object */ + __be64 zero_point; /* Size after which server has no data not written by us */ + __u8 type; /* Type of object */ + __u8 content; /* Content presence (enum cachefiles_content) */ + __u8 data[]; /* netfs coherency data */ } __packed; static const char cachefiles_xattr_cache[] = @@ -46,7 +49,10 @@ int cachefiles_set_object_xattr(struct cachefiles_object *object) if (!buf) return -ENOMEM; - buf->type = CACHEFILES_COOKIE_TYPE_DATA; + buf->object_size = cpu_to_be64(object->cookie->object_size); + buf->zero_point = 0; + buf->type = CACHEFILES_COOKIE_TYPE_DATA; + buf->content = object->content_info; if (len > 0) memcpy(buf->data, fscache_get_aux(object->cookie), len); @@ -54,7 +60,7 @@ int cachefiles_set_object_xattr(struct cachefiles_object *object) buf, sizeof(struct cachefiles_xattr) + len, 0); if (ret < 0) { trace_cachefiles_coherency(object, file_inode(file)->i_ino, - 0, + buf->content, cachefiles_coherency_set_fail); if (ret != -ENOMEM) cachefiles_io_error_obj( @@ -62,7 +68,7 @@ int cachefiles_set_object_xattr(struct cachefiles_object *object) "Failed to set xattr with error %d", ret); } else { trace_cachefiles_coherency(object, file_inode(file)->i_ino, - 0, + buf->content, cachefiles_coherency_set_ok); } @@ -100,12 +106,19 @@ int cachefiles_check_auxdata(struct cachefiles_object *object, struct file *file why = cachefiles_coherency_check_type; } else if (memcmp(buf->data, p, len) != 0) { why = cachefiles_coherency_check_aux; + } else if (be64_to_cpu(buf->object_size) != object->cookie->object_size) { + why = cachefiles_coherency_check_objsize; + } else if (buf->content == CACHEFILES_CONTENT_DIRTY) { + // TODO: Begin conflict resolution + pr_warn("Dirty object in cache\n"); + why = cachefiles_coherency_check_dirty; } else { why = cachefiles_coherency_check_ok; ret = 0; } - trace_cachefiles_coherency(object, file_inode(file)->i_ino, 0, why); + trace_cachefiles_coherency(object, file_inode(file)->i_ino, + buf->content, why); kfree(buf); return ret; }