From patchwork Fri Oct 21 13:05:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014739 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 D23C9C4332F for ; Fri, 21 Oct 2022 13:06:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230077AbiJUNGM (ORCPT ); Fri, 21 Oct 2022 09:06:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229854AbiJUNGK (ORCPT ); Fri, 21 Oct 2022 09:06:10 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0779E4E854; Fri, 21 Oct 2022 06:06:09 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 99EB761D11; Fri, 21 Oct 2022 13:06:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 251D1C43470; Fri, 21 Oct 2022 13:06:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357568; bh=tc1RUm4guOoZTsO0VdPQH+XnxC1sMtsO6DtotD5Lcrw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eAhmr9yWeS0wVEiVIgOWu1jlRYjG0WT5NB1ecC/uQxCrIfhjwPSsIUbf/tXfO3unE e0r32nDpuAZBm2Lop8vuIwFPI1Vu4ZtCzZErW16ygMxndEcmdWUD7xcbH8+RSOuWHB vbjv+2g0BW9bN052u7XJGnXbsFjzt8s1pPgNSITv5ezyP38rqsZ6oXhh9bQNyhEWvq /8aPUz2dUVAIjZ+JRXPCcyyTRgRJXyH/34pvoqmRLDbFcyfY4rwRbPoXR7Di581w/6 9p67AFlGaMiVsx5GqUjXNpFTm/3/gRaX+eu2ibO8xgOw+GSqs6BrjwgqwBPpxd/4Bq kc+5i0Af2xq7A== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH v8 1/8] fs: uninline inode_query_iversion Date: Fri, 21 Oct 2022 09:05:55 -0400 Message-Id: <20221021130602.99099-2-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Reviewed-by: NeilBrown Signed-off-by: Jeff Layton --- fs/libfs.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/iversion.h | 38 ++------------------------------------ 2 files changed, 38 insertions(+), 36 deletions(-) diff --git a/fs/libfs.c b/fs/libfs.c index 682d56345a1c..5ae81466a422 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1566,3 +1566,39 @@ bool inode_maybe_inc_iversion(struct inode *inode, bool force) return true; } EXPORT_SYMBOL(inode_maybe_inc_iversion); + +/** + * inode_query_iversion - read i_version for later use + * @inode: inode from which i_version should be read + * + * Read the inode i_version counter. This should be used by callers that wish + * to store the returned i_version for later comparison. This will guarantee + * that a later query of the i_version will result in a different value if + * anything has changed. + * + * In this implementation, we fetch the current value, set the QUERIED flag and + * then try to swap it into place with a cmpxchg, if it wasn't already set. If + * that fails, we try again with the newly fetched value from the cmpxchg. + */ +u64 inode_query_iversion(struct inode *inode) +{ + u64 cur, new; + + cur = inode_peek_iversion_raw(inode); + do { + /* If flag is already set, then no need to swap */ + if (cur & I_VERSION_QUERIED) { + /* + * This barrier (and the implicit barrier in the + * cmpxchg below) pairs with the barrier in + * inode_maybe_inc_iversion(). + */ + smp_mb(); + break; + } + + new = cur | I_VERSION_QUERIED; + } while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new)); + return cur >> I_VERSION_QUERIED_SHIFT; +} +EXPORT_SYMBOL(inode_query_iversion); diff --git a/include/linux/iversion.h b/include/linux/iversion.h index e27bd4f55d84..6755d8b4f20b 100644 --- a/include/linux/iversion.h +++ b/include/linux/iversion.h @@ -234,42 +234,6 @@ inode_peek_iversion(const struct inode *inode) return inode_peek_iversion_raw(inode) >> I_VERSION_QUERIED_SHIFT; } -/** - * inode_query_iversion - read i_version for later use - * @inode: inode from which i_version should be read - * - * Read the inode i_version counter. This should be used by callers that wish - * to store the returned i_version for later comparison. This will guarantee - * that a later query of the i_version will result in a different value if - * anything has changed. - * - * In this implementation, we fetch the current value, set the QUERIED flag and - * then try to swap it into place with a cmpxchg, if it wasn't already set. If - * that fails, we try again with the newly fetched value from the cmpxchg. - */ -static inline u64 -inode_query_iversion(struct inode *inode) -{ - u64 cur, new; - - cur = inode_peek_iversion_raw(inode); - do { - /* If flag is already set, then no need to swap */ - if (cur & I_VERSION_QUERIED) { - /* - * This barrier (and the implicit barrier in the - * cmpxchg below) pairs with the barrier in - * inode_maybe_inc_iversion(). - */ - smp_mb(); - break; - } - - new = cur | I_VERSION_QUERIED; - } while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new)); - return cur >> I_VERSION_QUERIED_SHIFT; -} - /* * For filesystems without any sort of change attribute, the best we can * do is fake one up from the ctime: @@ -283,6 +247,8 @@ static inline u64 time_to_chattr(struct timespec64 *t) return chattr; } +u64 inode_query_iversion(struct inode *inode); + /** * inode_eq_iversion_raw - check whether the raw i_version counter has changed * @inode: inode to check From patchwork Fri Oct 21 13:05:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014741 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 EF745C4167D for ; Fri, 21 Oct 2022 13:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230154AbiJUNGZ (ORCPT ); Fri, 21 Oct 2022 09:06:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44936 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229854AbiJUNGP (ORCPT ); Fri, 21 Oct 2022 09:06:15 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F22E44E854; Fri, 21 Oct 2022 06:06:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 991ACB82BFD; Fri, 21 Oct 2022 13:06:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4ECF9C433B5; Fri, 21 Oct 2022 13:06:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357570; bh=3UkiypkQG9xLfg+hS+eOV/U1/Tn/AJ7lMyTpKN5KYY4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nb7Yh47R45XqPtLKFsPoNljbrgHogii3eyJeQw8kYHjoaipnHpNizFXrsizMdjF+r PHs6urb8gnEaX6lrsQW9gE0F2HD99LWIL8nSL1J4uJAXnFtycQJ/32stK0OrJpeRq0 B3mEuntmnKKVKzBO7dC2b6RvaN2SHnSq4CGRVkcuMRHj0nL6p/NSeOTo35Lfog2xra DCIaG2PVYQsS177hQeS57Z/8fw+VgslZwMLCR+MrcbqfRFZ6QzoXM6WJk2x1ulJG1W 0Xl/0GfnwBEsjS/fhLgjWLg4EtHypRr2ix40fu2N5gbUexGEr+A0LI0o/nF3U+UBgB nGToooWNgVthg== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org, Colin Walters Subject: [PATCH v8 2/8] fs: clarify when the i_version counter must be updated Date: Fri, 21 Oct 2022 09:05:56 -0400 Message-Id: <20221021130602.99099-3-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org The i_version field in the kernel has had different semantics over the decades, but NFSv4 has certain expectations. Update the comments in iversion.h to describe when the i_version must change. Cc: Colin Walters Cc: NeilBrown Cc: Trond Myklebust Cc: Dave Chinner Signed-off-by: Jeff Layton --- include/linux/iversion.h | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/include/linux/iversion.h b/include/linux/iversion.h index 6755d8b4f20b..94f4dc620d01 100644 --- a/include/linux/iversion.h +++ b/include/linux/iversion.h @@ -9,8 +9,24 @@ * --------------------------- * The change attribute (i_version) is mandated by NFSv4 and is mostly for * knfsd, but is also used for other purposes (e.g. IMA). The i_version must - * appear different to observers if there was a change to the inode's data or - * metadata since it was last queried. + * appear larger to observers if there was an explicit change to the inode's + * data or metadata since it was last queried. + * + * An explicit change is one that would ordinarily result in a change to the + * inode status change time (aka ctime). i_version must appear to change, even + * if the ctime does not (since the whole point is to avoid missing updates due + * to timestamp granularity). If POSIX mandates that the ctime must change due + * to an operation, then the i_version counter must be incremented as well. + * + * Making the i_version update completely atomic with the operation itself would + * be prohibitively expensive. Traditionally the kernel has updated the times on + * directories after an operation that changes its contents. For regular files, + * the ctime is usually updated before the data is copied into the cache for a + * write. This means that there is a window of time when an observer can + * associate a new timestamp with old file contents. Since the purpose of the + * i_version is to allow for better cache coherency, the i_version must always + * be updated after the results of the operation are visible. Updating it before + * and after a change is also permitted. * * Observers see the i_version as a 64-bit number that never decreases. If it * remains the same since it was last checked, then nothing has changed in the From patchwork Fri Oct 21 13:05:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014742 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 E0505C43217 for ; Fri, 21 Oct 2022 13:06:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230167AbiJUNG1 (ORCPT ); Fri, 21 Oct 2022 09:06:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230093AbiJUNGQ (ORCPT ); Fri, 21 Oct 2022 09:06:16 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 37FCD26B4B6; Fri, 21 Oct 2022 06:06:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id DD05BB80C98; Fri, 21 Oct 2022 13:06:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8CA75C433D6; Fri, 21 Oct 2022 13:06:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357572; bh=HgePQpANeCyNlHouoSiNjOumB4QLppVOqg1bfK18//Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h9mbxrDiIYcO5M594qgki/ibDkOhScW1YhL3UPYCtHT9f8bCwJB8HCFDKdVUKC6wZ 6R0yel5DiglAUUcuypMfskj4I2Dnsz1Qy8q6Q0at8S8blOCfyYKgNLgvI+7HXh3MFN H8+z2wt25heOIhj7XLCQ4eIWO0hi/F1Ou++t2wk3HuueTb4crdcgIuEqy1YiWr6wte yhRSRrpLky8tlchsXPF0Emje/Gq97Dd8G2TojEbb9qM+k0IIXqbo+ksGyHATZo0ySV woTfZv5gdVrUSVlcW5Y1dwhknZhgwxeu1QYwc5eOiJNfeg+KaYQrOZ9o7pQT02mBPn RWddg7Kx8PrLw== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org, Jeff Layton Subject: [PATCH v8 3/8] vfs: plumb i_version handling into struct kstat Date: Fri, 21 Oct 2022 09:05:57 -0400 Message-Id: <20221021130602.99099-4-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Jeff Layton The NFS server has a lot of special handling for different types of change attribute access, depending on the underlying filesystem. In most cases, it's doing a getattr anyway and then fetching that value after the fact. Rather that do that, add a new STATX_CHANGE_COOKIE flag that is a kernel-only symbol (for now). If requested and getattr can implement it, it can fill out this field. For IS_I_VERSION inodes, add a generic implementation in vfs_getattr_nosec. Take care to mask STATX_CHANGE_COOKIE off in requests from userland and in the result mask. Since not all filesystems can give the same guarantees of monotonicity, claim a STATX_ATTR_CHANGE_MONOTONIC flag that filesystems can set to indicate that they offer an i_version value that can never go backward. Eventually if we decide to make the i_version available to userland, we can just designate a field for it in struct statx, and move the STATX_CHANGE_COOKIE definition to the uapi header. Reviewed-by: NeilBrown Signed-off-by: Jeff Layton --- fs/stat.c | 17 +++++++++++++++-- include/linux/stat.h | 9 +++++++++ 2 files changed, 24 insertions(+), 2 deletions(-) diff --git a/fs/stat.c b/fs/stat.c index ef50573c72a2..06fd3fc1ab84 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -119,6 +120,11 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat, stat->attributes_mask |= (STATX_ATTR_AUTOMOUNT | STATX_ATTR_DAX); + if ((request_mask & STATX_CHANGE_COOKIE) && IS_I_VERSION(inode)) { + stat->result_mask |= STATX_CHANGE_COOKIE; + stat->change_cookie = inode_query_iversion(inode); + } + mnt_userns = mnt_user_ns(path->mnt); if (inode->i_op->getattr) return inode->i_op->getattr(mnt_userns, path, stat, @@ -599,9 +605,11 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer) memset(&tmp, 0, sizeof(tmp)); - tmp.stx_mask = stat->result_mask; + /* STATX_CHANGE_COOKIE is kernel-only for now */ + tmp.stx_mask = stat->result_mask & ~STATX_CHANGE_COOKIE; tmp.stx_blksize = stat->blksize; - tmp.stx_attributes = stat->attributes; + /* STATX_ATTR_CHANGE_MONOTONIC is kernel-only for now */ + tmp.stx_attributes = stat->attributes & ~STATX_ATTR_CHANGE_MONOTONIC; tmp.stx_nlink = stat->nlink; tmp.stx_uid = from_kuid_munged(current_user_ns(), stat->uid); tmp.stx_gid = from_kgid_munged(current_user_ns(), stat->gid); @@ -640,6 +648,11 @@ int do_statx(int dfd, struct filename *filename, unsigned int flags, if ((flags & AT_STATX_SYNC_TYPE) == AT_STATX_SYNC_TYPE) return -EINVAL; + /* STATX_CHANGE_COOKIE is kernel-only for now. Ignore requests + * from userland. + */ + mask &= ~STATX_CHANGE_COOKIE; + error = vfs_statx(dfd, filename, flags, &stat, mask); if (error) return error; diff --git a/include/linux/stat.h b/include/linux/stat.h index ff277ced50e9..52150570d37a 100644 --- a/include/linux/stat.h +++ b/include/linux/stat.h @@ -52,6 +52,15 @@ struct kstat { u64 mnt_id; u32 dio_mem_align; u32 dio_offset_align; + u64 change_cookie; }; +/* These definitions are internal to the kernel for now. Mainly used by nfsd. */ + +/* mask values */ +#define STATX_CHANGE_COOKIE 0x40000000U /* Want/got stx_change_attr */ + +/* file attribute values */ +#define STATX_ATTR_CHANGE_MONOTONIC 0x8000000000000000ULL /* version monotonically increases */ + #endif From patchwork Fri Oct 21 13:05:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014775 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 51B2FC4321E for ; Fri, 21 Oct 2022 13:06:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230201AbiJUNGr (ORCPT ); Fri, 21 Oct 2022 09:06:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45140 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230111AbiJUNGX (ORCPT ); Fri, 21 Oct 2022 09:06:23 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8481426CDC5; Fri, 21 Oct 2022 06:06:17 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E96DEB82BCD; Fri, 21 Oct 2022 13:06:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CA703C433D7; Fri, 21 Oct 2022 13:06:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357574; bh=UIL2cdGHjlT4RFj+Zgh2BsP14ice/GgwMMKCqzmvxBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hsLE0fMHuJHPV6jz4Jziq/1iKtp4QV0jMIKjsH2Fz39fKLYKNvUrT4tAb7kgIxVeL SABL1AjbgKF5nDj3REqecr/dsLjjHRo8gDEioYaGR/moQ7nfQDH/YjJWZMu0nj1+su waaqxNgnmTafxvGCW4llU47U1OyTG5dfzyVWMGiF5c6GQ56/3f4ijCuSJL25jq4mSa VQnhkUyk+66LRvO82fjULKBIpFMFh9hN4rnI9S5bksB3mrMj5ogLbV5WWUyvsCXmiR djAuad9OAO2t+J1WicuSzVZPCDaa6r/NiswX76H/tpHQvsQ4t/EmXBB+Mh+VtWjURt 3OsND8of17C1Q== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH v8 4/8] nfs: report the inode version in getattr if requested Date: Fri, 21 Oct 2022 09:05:58 -0400 Message-Id: <20221021130602.99099-5-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Allow NFS to report the i_version in getattr requests. Since the cost to fetch it is relatively cheap, do it unconditionally and just set the flag if it looks like it's valid. Also, conditionally enable the MONOTONIC flag when the server reports its change attr type as such. Reviewed-by: NeilBrown Signed-off-by: Jeff Layton --- fs/nfs/inode.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 6b2cfa59a1a2..f70f11df1ee0 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -825,6 +825,8 @@ static u32 nfs_get_valid_attrmask(struct inode *inode) reply_mask |= STATX_UID | STATX_GID; if (!(cache_validity & NFS_INO_INVALID_BLOCKS)) reply_mask |= STATX_BLOCKS; + if (!(cache_validity & NFS_INO_INVALID_CHANGE)) + reply_mask |= STATX_CHANGE_COOKIE; return reply_mask; } @@ -843,7 +845,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path, request_mask &= STATX_TYPE | STATX_MODE | STATX_NLINK | STATX_UID | STATX_GID | STATX_ATIME | STATX_MTIME | STATX_CTIME | - STATX_INO | STATX_SIZE | STATX_BLOCKS; + STATX_INO | STATX_SIZE | STATX_BLOCKS | STATX_BTIME | + STATX_CHANGE_COOKIE; if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) { if (readdirplus_enabled) @@ -851,8 +854,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path, goto out_no_revalidate; } - /* Flush out writes to the server in order to update c/mtime. */ - if ((request_mask & (STATX_CTIME | STATX_MTIME)) && + /* Flush out writes to the server in order to update c/mtime/version. */ + if ((request_mask & (STATX_CTIME | STATX_MTIME | STATX_CHANGE_COOKIE)) && S_ISREG(inode->i_mode)) filemap_write_and_wait(inode->i_mapping); @@ -872,7 +875,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path, /* Is the user requesting attributes that might need revalidation? */ if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME| STATX_MTIME|STATX_UID|STATX_GID| - STATX_SIZE|STATX_BLOCKS))) + STATX_SIZE|STATX_BLOCKS| + STATX_CHANGE_COOKIE))) goto out_no_revalidate; /* Check whether the cached attributes are stale */ @@ -910,6 +914,10 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path, generic_fillattr(&init_user_ns, inode, stat); stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode)); + stat->change_cookie = inode_peek_iversion_raw(inode); + stat->attributes_mask |= STATX_ATTR_CHANGE_MONOTONIC; + if (server->change_attr_type != NFS4_CHANGE_TYPE_IS_UNDEFINED) + stat->attributes |= STATX_ATTR_CHANGE_MONOTONIC; if (S_ISDIR(inode->i_mode)) stat->blksize = NFS_SERVER(inode)->dtsize; out: From patchwork Fri Oct 21 13:05:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014776 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 80041C4332F for ; Fri, 21 Oct 2022 13:07:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230227AbiJUNG7 (ORCPT ); Fri, 21 Oct 2022 09:06:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230124AbiJUNGX (ORCPT ); Fri, 21 Oct 2022 09:06:23 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5784F26B4BE; Fri, 21 Oct 2022 06:06:18 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7DE8D61E9D; Fri, 21 Oct 2022 13:06:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 044E4C433D6; Fri, 21 Oct 2022 13:06:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357576; bh=XTCQklTYch506fsKvxW5ImA5FCnKyk22+LeCOXARq2w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sOHJ0lyDnodI/pMdW/riO8Mlc7c3TXOUu3cVbHVd0S3sDMkrwQL3useK0XlgQZlSz O0wVWgujInzFgk7f2U+CS93aXxC9Ut4leanCI4L9eyimSUvz/BOrPpxbJ34njq1PJq +jjzkL/YehSxS2O/hgAG0+e+x0uPY/EPCwAme6V1t8tG/L6LtoREMaRXtw59nOYDnz xB6wzbZ62nsMC04zkIlU2EnGtMUQWguL7aBZt8sxvD+L4IfT93F8RkTd8OrpXEEZcY o2e4qO1gm2ecMPUFdp7NQVspCgHEl+eypbf9GaKDBTr6G7zmrTR73aLKp7mTazsJ7R XQH/Jr8JywX0A== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH v8 5/8] ceph: report the inode version in getattr if requested Date: Fri, 21 Oct 2022 09:05:59 -0400 Message-Id: <20221021130602.99099-6-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org When getattr requests the STX_CHANGE_COOKIE, request the full gamut of caps (similarly to how ctime is handled). When the change attribute seems to be valid, return it in the change_cookie field and set the flag in the reply mask. Also, unconditionally enable STATX_ATTR_CHANGE_MONOTONIC. Reviewed-by: Xiubo Li Signed-off-by: Jeff Layton --- fs/ceph/inode.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 4af5e55abc15..0e2e6ca399a9 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -2417,10 +2417,10 @@ static int statx_to_caps(u32 want, umode_t mode) { int mask = 0; - if (want & (STATX_MODE|STATX_UID|STATX_GID|STATX_CTIME|STATX_BTIME)) + if (want & (STATX_MODE|STATX_UID|STATX_GID|STATX_CTIME|STATX_BTIME|STATX_CHANGE_COOKIE)) mask |= CEPH_CAP_AUTH_SHARED; - if (want & (STATX_NLINK|STATX_CTIME)) { + if (want & (STATX_NLINK|STATX_CTIME|STATX_CHANGE_COOKIE)) { /* * The link count for directories depends on inode->i_subdirs, * and that is only updated when Fs caps are held. @@ -2431,11 +2431,10 @@ static int statx_to_caps(u32 want, umode_t mode) mask |= CEPH_CAP_LINK_SHARED; } - if (want & (STATX_ATIME|STATX_MTIME|STATX_CTIME|STATX_SIZE| - STATX_BLOCKS)) + if (want & (STATX_ATIME|STATX_MTIME|STATX_CTIME|STATX_SIZE|STATX_BLOCKS|STATX_CHANGE_COOKIE)) mask |= CEPH_CAP_FILE_SHARED; - if (want & (STATX_CTIME)) + if (want & (STATX_CTIME|STATX_CHANGE_COOKIE)) mask |= CEPH_CAP_XATTR_SHARED; return mask; @@ -2478,6 +2477,11 @@ int ceph_getattr(struct user_namespace *mnt_userns, const struct path *path, valid_mask |= STATX_BTIME; } + if (request_mask & STATX_CHANGE_COOKIE) { + stat->change_cookie = inode_peek_iversion_raw(inode); + valid_mask |= STATX_CHANGE_COOKIE; + } + if (ceph_snap(inode) == CEPH_NOSNAP) stat->dev = sb->s_dev; else @@ -2519,6 +2523,8 @@ int ceph_getattr(struct user_namespace *mnt_userns, const struct path *path, stat->nlink = 1 + 1 + ci->i_subdirs; } + stat->attributes_mask |= STATX_ATTR_CHANGE_MONOTONIC; + stat->attributes |= STATX_ATTR_CHANGE_MONOTONIC; stat->result_mask = request_mask & valid_mask; return err; } From patchwork Fri Oct 21 13:06:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014778 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 8A46EC4332F for ; Fri, 21 Oct 2022 13:07:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230271AbiJUNHH (ORCPT ); Fri, 21 Oct 2022 09:07:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45144 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230144AbiJUNGZ (ORCPT ); Fri, 21 Oct 2022 09:06:25 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 224C826CDE6; Fri, 21 Oct 2022 06:06:20 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id A93F161EA3; Fri, 21 Oct 2022 13:06:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2ED38C43470; Fri, 21 Oct 2022 13:06:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357579; bh=LBaEFSh5DOeyzDGsOyxhMwQpssm5JK6u2HESg5ybNII=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pAkgaXyiv8pAQmQv5zw0PS1FBjghpTjn/+TC5F1qoVrIhLFKWhVZhkykR9YVZDftb 0gvUciPyF8NPSjTQoDmZzrpREJvKzc3SEH0D94VojrUhWRJAPYDt7BkZ92qmUm2YV1 HNU03eZI2/8YPtlqegsQcDdM/eWg1nealcAZHLzfm4oPfXqs0Nw0mZ++2Jmm6QmYBb NUMWmb3sJLfEKoBlTN/vsVY/71rC4StDmuft8LwpOWTMO7YIfORfEW3Q4yGBnMEpj6 u/+aMApkoVUwyk6JCZ1dq1yaexLhZP0AOc0Shj9z1encZN2QKLppMJt/+IrfH2fslP y15IEoy/SuYLw== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH v8 6/8] nfsd: move nfsd4_change_attribute to nfsfh.c Date: Fri, 21 Oct 2022 09:06:00 -0400 Message-Id: <20221021130602.99099-7-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is a pretty big function for inlining. Move it to being non-inlined. Reviewed-by: NeilBrown Signed-off-by: Jeff Layton --- fs/nfsd/nfsfh.c | 27 +++++++++++++++++++++++++++ fs/nfsd/nfsfh.h | 29 +---------------------------- 2 files changed, 28 insertions(+), 28 deletions(-) diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index d73434200df9..7030d9209903 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -748,3 +748,30 @@ enum fsid_source fsid_source(const struct svc_fh *fhp) return FSIDSOURCE_UUID; return FSIDSOURCE_DEV; } + +/* + * We could use i_version alone as the change attribute. However, + * i_version can go backwards after a reboot. On its own that doesn't + * necessarily cause a problem, but if i_version goes backwards and then + * is incremented again it could reuse a value that was previously used + * before boot, and a client who queried the two values might + * incorrectly assume nothing changed. + * + * By using both ctime and the i_version counter we guarantee that as + * long as time doesn't go backwards we never reuse an old value. + */ +u64 nfsd4_change_attribute(struct kstat *stat, struct inode *inode) +{ + if (inode->i_sb->s_export_op->fetch_iversion) + return inode->i_sb->s_export_op->fetch_iversion(inode); + else if (IS_I_VERSION(inode)) { + u64 chattr; + + chattr = stat->ctime.tv_sec; + chattr <<= 30; + chattr += stat->ctime.tv_nsec; + chattr += inode_query_iversion(inode); + return chattr; + } else + return time_to_chattr(&stat->ctime); +} diff --git a/fs/nfsd/nfsfh.h b/fs/nfsd/nfsfh.h index c3ae6414fc5c..4c223a7a91d4 100644 --- a/fs/nfsd/nfsfh.h +++ b/fs/nfsd/nfsfh.h @@ -291,34 +291,7 @@ static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp) fhp->fh_pre_saved = false; } -/* - * We could use i_version alone as the change attribute. However, - * i_version can go backwards after a reboot. On its own that doesn't - * necessarily cause a problem, but if i_version goes backwards and then - * is incremented again it could reuse a value that was previously used - * before boot, and a client who queried the two values might - * incorrectly assume nothing changed. - * - * By using both ctime and the i_version counter we guarantee that as - * long as time doesn't go backwards we never reuse an old value. - */ -static inline u64 nfsd4_change_attribute(struct kstat *stat, - struct inode *inode) -{ - if (inode->i_sb->s_export_op->fetch_iversion) - return inode->i_sb->s_export_op->fetch_iversion(inode); - else if (IS_I_VERSION(inode)) { - u64 chattr; - - chattr = stat->ctime.tv_sec; - chattr <<= 30; - chattr += stat->ctime.tv_nsec; - chattr += inode_query_iversion(inode); - return chattr; - } else - return time_to_chattr(&stat->ctime); -} - +u64 nfsd4_change_attribute(struct kstat *stat, struct inode *inode); extern void fh_fill_pre_attrs(struct svc_fh *fhp); extern void fh_fill_post_attrs(struct svc_fh *fhp); extern void fh_fill_both_attrs(struct svc_fh *fhp); From patchwork Fri Oct 21 13:06:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014777 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 D2B83C43219 for ; Fri, 21 Oct 2022 13:07:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230261AbiJUNHF (ORCPT ); Fri, 21 Oct 2022 09:07:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230161AbiJUNG1 (ORCPT ); Fri, 21 Oct 2022 09:06:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F1E026B4BC; Fri, 21 Oct 2022 06:06:23 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id DBEB961D11; Fri, 21 Oct 2022 13:06:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AA3AC433C1; Fri, 21 Oct 2022 13:06:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357581; bh=o/W2G2/aFsV8kJG6gd0NpL/EXPewZKlzXLb+OuWvXdY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=O/xdn7ai761Bq8YKbEtusR1eNhStdXiq4DeNtVyjL27dDvHnjkTfa/NuLCbwbdAMv zQNuZmSAAzKg2FYhKZnEfk5qNwBii0mwAfeXdchQ0Q+f83XSaGCclNd0/zAhIbmlwX gDL9lBAKlfAMLqJQ3ls/m0Onl0oodOEz9MW+ev1MR54wsIJBOuAqJkQswNfe+HzWOW 8TnJIn8ll/n3PK4WuURjGs/9L2NRayMB7g3RI0wBLwaT9oEhl1yjgKtmmuMTNYhors 3Gxek3h73fYx1bl+sfamccL3WnHB0JVtITLXeCiltyKVqvjwN2Bv7NNMsj0Ym6yRzq k0/ljrt+L8opw== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH v8 7/8] nfsd: use the getattr operation to fetch i_version Date: Fri, 21 Oct 2022 09:06:01 -0400 Message-Id: <20221021130602.99099-8-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Now that we can call into vfs_getattr to get the i_version field, use that facility to fetch it instead of doing it in nfsd4_change_attribute. Neil also pointed out recently that IS_I_VERSION directory operations are always logged, and so we only need to mitigate the rollback problem on regular files. Also, we don't need to factor in the ctime when reexporting NFS or Ceph. Set the STATX_CHANGE_COOKIE (and BTIME) bits in the request when we're dealing with a v4 request. Then, instead of looking at IS_I_VERSION when generating the change attr, look at the result mask and only use it if STATX_CHANGE_COOKIE is set. Change nfsd4_change_attribute to only factor in the ctime if it's a regular file and the fs doesn't advertise STATX_ATTR_CHANGE_MONOTONIC. Reviewed-by: NeilBrown Signed-off-by: Jeff Layton --- fs/nfsd/nfs4xdr.c | 4 +++- fs/nfsd/nfsfh.c | 54 +++++++++++++++++++++++++++++++---------------- fs/nfsd/vfs.h | 7 +++++- 3 files changed, 45 insertions(+), 20 deletions(-) diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index bcfeb1a922c0..06eb1aa7846b 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2906,7 +2906,9 @@ nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp, goto out; } - err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT); + err = vfs_getattr(&path, &stat, + STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE, + AT_STATX_SYNC_AS_STAT); if (err) goto out_nfserr; if (!(stat.result_mask & STATX_BTIME)) diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index 7030d9209903..3e09129db340 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -628,6 +628,10 @@ void fh_fill_pre_attrs(struct svc_fh *fhp) stat.mtime = inode->i_mtime; stat.ctime = inode->i_ctime; stat.size = inode->i_size; + if (v4 && IS_I_VERSION(inode)) { + stat.change_cookie = inode_query_iversion(inode); + stat.result_mask |= STATX_CHANGE_COOKIE; + } } if (v4) fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode); @@ -659,6 +663,10 @@ void fh_fill_post_attrs(struct svc_fh *fhp) if (err) { fhp->fh_post_saved = false; fhp->fh_post_attr.ctime = inode->i_ctime; + if (v4 && IS_I_VERSION(inode)) { + fhp->fh_post_attr.change_cookie = inode_query_iversion(inode); + fhp->fh_post_attr.result_mask |= STATX_CHANGE_COOKIE; + } } else fhp->fh_post_saved = true; if (v4) @@ -750,28 +758,38 @@ enum fsid_source fsid_source(const struct svc_fh *fhp) } /* - * We could use i_version alone as the change attribute. However, - * i_version can go backwards after a reboot. On its own that doesn't - * necessarily cause a problem, but if i_version goes backwards and then - * is incremented again it could reuse a value that was previously used - * before boot, and a client who queried the two values might - * incorrectly assume nothing changed. + * We could use i_version alone as the change attribute. However, i_version + * can go backwards on a regular file after an unclean shutdown. On its own + * that doesn't necessarily cause a problem, but if i_version goes backwards + * and then is incremented again it could reuse a value that was previously + * used before boot, and a client who queried the two values might incorrectly + * assume nothing changed. + * + * By using both ctime and the i_version counter we guarantee that as long as + * time doesn't go backwards we never reuse an old value. If the filesystem + * advertises STATX_ATTR_CHANGE_MONOTONIC, then this mitigation is not + * needed. * - * By using both ctime and the i_version counter we guarantee that as - * long as time doesn't go backwards we never reuse an old value. + * We only need to do this for regular files as well. For directories, we + * assume that the new change attr is always logged to stable storage in some + * fashion before the results can be seen. */ u64 nfsd4_change_attribute(struct kstat *stat, struct inode *inode) { + u64 chattr; + if (inode->i_sb->s_export_op->fetch_iversion) return inode->i_sb->s_export_op->fetch_iversion(inode); - else if (IS_I_VERSION(inode)) { - u64 chattr; - - chattr = stat->ctime.tv_sec; - chattr <<= 30; - chattr += stat->ctime.tv_nsec; - chattr += inode_query_iversion(inode); - return chattr; - } else - return time_to_chattr(&stat->ctime); + if (stat->result_mask & STATX_CHANGE_COOKIE) { + chattr = stat->change_cookie; + + if (S_ISREG(inode->i_mode) && + !(stat->attributes & STATX_ATTR_CHANGE_MONOTONIC)) { + chattr += (u64)stat->ctime.tv_sec << 30; + chattr += stat->ctime.tv_nsec; + } + } else { + chattr = time_to_chattr(&stat->ctime); + } + return chattr; } diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index 120521bc7b24..1b205a27f961 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -168,9 +168,14 @@ static inline void fh_drop_write(struct svc_fh *fh) static inline __be32 fh_getattr(const struct svc_fh *fh, struct kstat *stat) { + u32 request_mask = STATX_BASIC_STATS; struct path p = {.mnt = fh->fh_export->ex_path.mnt, .dentry = fh->fh_dentry}; - return nfserrno(vfs_getattr(&p, stat, STATX_BASIC_STATS, + + if (fh->fh_maxsize == NFS4_FHSIZE) + request_mask |= (STATX_BTIME | STATX_CHANGE_COOKIE); + + return nfserrno(vfs_getattr(&p, stat, request_mask, AT_STATX_SYNC_AS_STAT)); } From patchwork Fri Oct 21 13:06:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13014779 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 31CA0C43217 for ; Fri, 21 Oct 2022 13:07:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230336AbiJUNHr (ORCPT ); Fri, 21 Oct 2022 09:07:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230242AbiJUNHA (ORCPT ); Fri, 21 Oct 2022 09:07:00 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45E7826C440; Fri, 21 Oct 2022 06:06:25 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 12D8E61E9D; Fri, 21 Oct 2022 13:06:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B9A9C43470; Fri, 21 Oct 2022 13:06:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1666357583; bh=A8k10DQZe5/j0onCVE9QxI6roj/l9wmzJGTvPKqqG6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QFs7aCqFVXAySekdGZ4p3ryfOiNkMaOpcCi7/4qlgmjk3VblAe3HSrtPXkwuMDtrl 7P37FbVpYNeUO9d28qUit+vYGLEv2jI60BUCYdM2yL4fjYNPTTg+DNSfw0fGli+TOx kDj69s1BfwU0UQGg7fQUXOed31wbkFKSTqP5aYXeUm274epkCIIr7AsTuJ2DcvF4RK PHjdGEjjp3+y2DEIQgbcG5pdAtKbSXXsmObb4RPSMc865STbUJCy0cdgR94fcpxc5F 4Ehsb7+6NSOIJVsADEmPsHvLXr9LBTjzX8EfxiGY+hJ4xXXp43WVyIGG04imNsNT8k 28IwdbMkB7k8w== From: Jeff Layton To: tytso@mit.edu, adilger.kernel@dilger.ca, djwong@kernel.org, david@fromorbit.com, trondmy@hammerspace.com, neilb@suse.de, viro@zeniv.linux.org.uk, zohar@linux.ibm.com, xiubli@redhat.com, chuck.lever@oracle.com, lczerner@redhat.com, jack@suse.cz, bfields@fieldses.org, brauner@kernel.org, fweimer@redhat.com Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ceph-devel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org Subject: [PATCH v8 8/8] nfsd: remove fetch_iversion export operation Date: Fri, 21 Oct 2022 09:06:02 -0400 Message-Id: <20221021130602.99099-9-jlayton@kernel.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221021130602.99099-1-jlayton@kernel.org> References: <20221021130602.99099-1-jlayton@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Now that the i_version counter is reported in struct kstat, there is no need for this export operation. Reviewed-by: NeilBrown Signed-off-by: Jeff Layton --- fs/nfs/export.c | 7 ------- fs/nfsd/nfsfh.c | 3 --- include/linux/exportfs.h | 1 - 3 files changed, 11 deletions(-) diff --git a/fs/nfs/export.c b/fs/nfs/export.c index 01596f2d0a1e..1a9d5aa51dfb 100644 --- a/fs/nfs/export.c +++ b/fs/nfs/export.c @@ -145,17 +145,10 @@ nfs_get_parent(struct dentry *dentry) return parent; } -static u64 nfs_fetch_iversion(struct inode *inode) -{ - nfs_revalidate_inode(inode, NFS_INO_INVALID_CHANGE); - return inode_peek_iversion_raw(inode); -} - const struct export_operations nfs_export_ops = { .encode_fh = nfs_encode_fh, .fh_to_dentry = nfs_fh_to_dentry, .get_parent = nfs_get_parent, - .fetch_iversion = nfs_fetch_iversion, .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK| EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS| EXPORT_OP_NOATOMIC_ATTR, diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c index 3e09129db340..bd450b141ca4 100644 --- a/fs/nfsd/nfsfh.c +++ b/fs/nfsd/nfsfh.c @@ -778,11 +778,8 @@ u64 nfsd4_change_attribute(struct kstat *stat, struct inode *inode) { u64 chattr; - if (inode->i_sb->s_export_op->fetch_iversion) - return inode->i_sb->s_export_op->fetch_iversion(inode); if (stat->result_mask & STATX_CHANGE_COOKIE) { chattr = stat->change_cookie; - if (S_ISREG(inode->i_mode) && !(stat->attributes & STATX_ATTR_CHANGE_MONOTONIC)) { chattr += (u64)stat->ctime.tv_sec << 30; diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index fe848901fcc3..9f4d4bcbf251 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -213,7 +213,6 @@ struct export_operations { bool write, u32 *device_generation); int (*commit_blocks)(struct inode *inode, struct iomap *iomaps, int nr_iomaps, struct iattr *iattr); - u64 (*fetch_iversion)(struct inode *); #define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */ #define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */ #define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */