From patchwork Wed May 25 17:24:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 12861451 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C317CC433F5 for ; Wed, 25 May 2022 17:23:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245655AbiEYRX7 (ORCPT ); Wed, 25 May 2022 13:23:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229586AbiEYRXz (ORCPT ); Wed, 25 May 2022 13:23:55 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A3A395A34; Wed, 25 May 2022 10:23:54 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 01CC41F897; Wed, 25 May 2022 17:23:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1653499433; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=6qP67cQkbfdwGwYUYrK9vkjemtwnVTSyEF2Iosy1P/8=; b=oTCyXpCmzqlmjVnYszS+cBLQNp+21ld+4SES/K+A6d6mrMqg2wasaXwPp0AnrIG2Eoi1Cc 1tPk0R+dQhOQKcbTSVe+KsrTdBF2RLFFOOjQm4iEED7qQWY6PgUrT7oAzZdTlomkXRzYUQ ugvwjvIiJdn3oQRg6slrXdDFwr2SKfM= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1653499433; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=6qP67cQkbfdwGwYUYrK9vkjemtwnVTSyEF2Iosy1P/8=; b=W/W0n83VL9Wg1HoiRSNld28OQaHegHgpWReZkEEd8uz/ao0AfOPmnI7yBj3LuZ4ru8UTPu xDh+tYBHZsOPw9BQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 824F513ADF; Wed, 25 May 2022 17:23:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id +R0kHChmjmJ4PQAAMHmgww (envelope-from ); Wed, 25 May 2022 17:23:52 +0000 Received: from localhost (brahms.olymp [local]) by brahms.olymp (OpenSMTPD) with ESMTPA id 37a1b265; Wed, 25 May 2022 17:24:28 +0000 (UTC) From: =?utf-8?q?Lu=C3=ADs_Henriques?= To: Jeff Layton , Xiubo Li , Ilya Dryomov Cc: ceph-devel@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Lu?= =?utf-8?q?=C3=ADs_Henriques?= Subject: [RFC PATCH v2] ceph: prevent a client from exceeding the MDS maximum xattr size Date: Wed, 25 May 2022 18:24:27 +0100 Message-Id: <20220525172427.3692-1-lhenriques@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org The MDS tries to enforce a limit on the total key/values in extended attributes. However, this limit is enforced only if doing a synchronous operation (MDS_OP_SETXATTR) -- if we're buffering the xattrs, the MDS doesn't have a chance to enforce these limits. This patch adds support for an extra feature bit that will allow the client to get the MDS max_xattr_pairs_size setting in the session message. Then, when setting an xattr, the kernel will revert to do a synchronous operation if that maximum size is exceeded. While there, fix a dout() that would trigger a printk warning: [ 98.718078] ------------[ cut here ]------------ [ 98.719012] precision 65536 too large [ 98.719039] WARNING: CPU: 1 PID: 3755 at lib/vsprintf.c:2703 vsnprintf+0x5e3/0x600 ... URL: https://tracker.ceph.com/issues/55725 Signed-off-by: Luís Henriques --- fs/ceph/mds_client.c | 12 ++++++++++++ fs/ceph/mds_client.h | 15 ++++++++++++++- fs/ceph/xattr.c | 12 ++++++++---- 3 files changed, 34 insertions(+), 5 deletions(-) * Changes since v1 Added support for new feature bit to get the MDS max_xattr_pairs_size setting. Also note that this patch relies on a patch that hasn't been merged yet ("ceph: use correct index when encoding client supported features"), otherwise the new feature bit won't be correctly encoded. diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 35597fafb48c..87a25b7cf496 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -3500,6 +3500,7 @@ static void handle_session(struct ceph_mds_session *session, struct ceph_mds_session_head *h; u32 op; u64 seq, features = 0; + u64 max_xattr_pairs_size = 0; int wake = 0; bool blocklisted = false; @@ -3545,6 +3546,9 @@ static void handle_session(struct ceph_mds_session *session, } } + if (msg_version >= 6) + ceph_decode_64_safe(&p, end, max_xattr_pairs_size, bad); + mutex_lock(&mdsc->mutex); if (op == CEPH_SESSION_CLOSE) { ceph_get_mds_session(session); @@ -3552,6 +3556,12 @@ static void handle_session(struct ceph_mds_session *session, } /* FIXME: this ttl calculation is generous */ session->s_ttl = jiffies + HZ*mdsc->mdsmap->m_session_autoclose; + + if (max_xattr_pairs_size && (op == CEPH_SESSION_OPEN)) { + dout("Changing MDS max xattrs pairs size: %llu => %llu\n", + mdsc->max_xattr_pairs_size, max_xattr_pairs_size); + mdsc->max_xattr_pairs_size = max_xattr_pairs_size; + } mutex_unlock(&mdsc->mutex); mutex_lock(&session->s_mutex); @@ -4761,6 +4771,8 @@ int ceph_mdsc_init(struct ceph_fs_client *fsc) strscpy(mdsc->nodename, utsname()->nodename, sizeof(mdsc->nodename)); + mdsc->max_xattr_pairs_size = MDS_MAX_XATTR_PAIRS_SIZE; + fsc->mdsc = mdsc; return 0; diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h index ca32f26f5eed..3db777df6d88 100644 --- a/fs/ceph/mds_client.h +++ b/fs/ceph/mds_client.h @@ -29,8 +29,11 @@ enum ceph_feature_type { CEPHFS_FEATURE_MULTI_RECONNECT, CEPHFS_FEATURE_DELEG_INO, CEPHFS_FEATURE_METRIC_COLLECT, + CEPHFS_FEATURE_ALTERNATE_NAME, + CEPHFS_FEATURE_NOTIFY_SESSION_STATE, + CEPHFS_FEATURE_MAX_XATTR_PAIRS_SIZE, - CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_METRIC_COLLECT, + CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_MAX_XATTR_PAIRS_SIZE, }; /* @@ -45,9 +48,16 @@ enum ceph_feature_type { CEPHFS_FEATURE_MULTI_RECONNECT, \ CEPHFS_FEATURE_DELEG_INO, \ CEPHFS_FEATURE_METRIC_COLLECT, \ + CEPHFS_FEATURE_MAX_XATTR_PAIRS_SIZE, \ } #define CEPHFS_FEATURES_CLIENT_REQUIRED {} +/* + * Maximum size of xattrs the MDS can handle per inode by default. This + * includes the attribute name and 4+4 bytes for the key/value sizes. + */ +#define MDS_MAX_XATTR_PAIRS_SIZE (1<<16) /* 64K */ + /* * Some lock dependencies: * @@ -404,6 +414,9 @@ struct ceph_mds_client { struct rb_root quotarealms_inodes; struct mutex quotarealms_inodes_mutex; + /* maximum aggregate size of extended attributes on a file */ + u64 max_xattr_pairs_size; + /* * snap_rwsem will cover cap linkage into snaprealms, and * realm snap contexts. (later, we can do per-realm snap diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c index 8c2dc2c762a4..175a8c1449aa 100644 --- a/fs/ceph/xattr.c +++ b/fs/ceph/xattr.c @@ -1086,7 +1086,7 @@ static int ceph_sync_setxattr(struct inode *inode, const char *name, flags |= CEPH_XATTR_REMOVE; } - dout("setxattr value=%.*s\n", (int)size, value); + dout("setxattr value size: %ld\n", size); /* do request */ req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS); @@ -1184,8 +1184,14 @@ int __ceph_setxattr(struct inode *inode, const char *name, spin_lock(&ci->i_ceph_lock); retry: issued = __ceph_caps_issued(ci, NULL); - if (ci->i_xattrs.version == 0 || !(issued & CEPH_CAP_XATTR_EXCL)) + required_blob_size = __get_required_blob_size(ci, name_len, val_len); + if ((ci->i_xattrs.version == 0) || !(issued & CEPH_CAP_XATTR_EXCL) || + (required_blob_size >= mdsc->max_xattr_pairs_size)) { + dout("%s do sync setxattr: version: %llu size: %d max: %llu\n", + __func__, ci->i_xattrs.version, required_blob_size, + mdsc->max_xattr_pairs_size); goto do_sync; + } if (!lock_snap_rwsem && !ci->i_head_snapc) { lock_snap_rwsem = true; @@ -1201,8 +1207,6 @@ int __ceph_setxattr(struct inode *inode, const char *name, ceph_cap_string(issued)); __build_xattrs(inode); - required_blob_size = __get_required_blob_size(ci, name_len, val_len); - if (!ci->i_xattrs.prealloc_blob || required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) { struct ceph_buffer *blob;