From nobody Fri Nov 29 22:39:35 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BE0C71D31AB; Sat, 14 Sep 2024 17:07:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726333652; cv=none; b=RW8OeaykdGsLkKXYXG2ybq2taEpVi4Vxi/+aZsaEnkiu8rOK81CksEizIF/g431MKawHIKbcM/u+z9L3lFcdJC6IOnUxobytaQ4uW0kMl+qqNb2cFxBfqDbSjdJZwXfcsl1G46Xnu7bRoGnoTEUcUU3VvxtcLNmTG6vvcxzLYIQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726333652; c=relaxed/simple; bh=9/XBaGHpEs7172AZ1LJbIYF77AkYkko2J3CyGkwFfPc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Y/AMT9Z8d/OaqoW3/FA1s2Vuqi4t6Vqqq1RXol8b81q1VggO82AGaxPGRMQ8Sh50aLvwVOV0aaj7h4bALf+1bCKq1Z5+QpDd/sFKLCzmVKtJkSvRLSwTtICDCwD1DJrn7L4z4G39d6zdqPk8xsuBA+cuoFT0KAVFS3PNQ6DPJz4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZCOpnIci; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZCOpnIci" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A40BFC4CED2; Sat, 14 Sep 2024 17:07:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1726333650; bh=9/XBaGHpEs7172AZ1LJbIYF77AkYkko2J3CyGkwFfPc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=ZCOpnIci9ttfjhsJzdlcwY1nYcNFUbiD1dipumSZt87w3MACEWPzaGdku7J58Ocut 7HnIhiMDQAIoUXSnyL904jY9IAOTXxIxiIR1LWhnuDUgwkupg8+oSupET1iJss0j6j 58zUooisPaBhdB4W13l3tpEKZ/zhOH9LDKDAINhpnCC8r6Ajx/nmf0AhEdr/uUo0Oc CjPVoNLSKEWHCQEGyvzxrzRJEqsldglkPe2BcUgUhDpbf1SwnPrBrDTtNubansxew5 /6dR/EZrDa8YIK8KYySDQSYx4czlItz8HflLG4e7RWbLXVLXgWgfxKuTUczpylZw1Y XmuT7q3oYEnbw== From: Jeff Layton Date: Sat, 14 Sep 2024 13:07:16 -0400 Subject: [PATCH v8 03/11] fs: have setattr_copy handle multigrain timestamps appropriately Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20240914-mgtime-v8-3-5bd872330bed@kernel.org> References: <20240914-mgtime-v8-0-5bd872330bed@kernel.org> In-Reply-To: <20240914-mgtime-v8-0-5bd872330bed@kernel.org> To: John Stultz , Thomas Gleixner , Stephen Boyd , Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Chandan Babu R , "Darrick J. Wong" , Theodore Ts'o , Andreas Dilger , Chris Mason , Josef Bacik , David Sterba , Hugh Dickins , Andrew Morton , Chuck Lever , Vadim Fedorenko Cc: Randy Dunlap , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mm@kvack.org, Jeff Layton X-Mailer: b4 0.14.1 X-Developer-Signature: v=1; a=openpgp-sha256; l=3540; i=jlayton@kernel.org; h=from:subject:message-id; bh=9/XBaGHpEs7172AZ1LJbIYF77AkYkko2J3CyGkwFfPc=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBm5cLFOqolNl/xZsf6WUTQki64XUYvRpIiwgA6E 8I95y8GTEWJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZuXCxQAKCRAADmhBGVaC FV3xEACKkDWRY2iDTOCIYD0Vc9W6MmuR9SEw96FMPF1lO+jbD26E8dxf0hrkhre9oBUikVhQVAK mso6eiHYIR5pTUeQadzyNEdK8QQwVDVIq95IG5F1sp5NZBdW+myoBZzaVbX6i42BeAmKBFm+EAR uc0WhyS1vxp/5G2TzkAGEot1iMRUtgptkCYA1ksBNkbAQuAUpc28ksyE7gtXE+XTYRjt1+h7lb8 cXQakAWWrU9Q6lvD5Eu3kI30Ml47tKa/aLFyPct/CMVP1wzQT79+5bCbUQeoa3EmPsYZG3i6tgS TXVg1FFqlViABoU1Khb1RT0U4PY2i8jCrcZbncFaS2IJqlBSy2X3Eq618IyGtKF2ZOLoZV80axd hJFet3BIa4P64HQ4Fwjedi/V4OdyKodhAbbAzinWTRT89vH6DMI6nNlFCRSayI4PGlcoqrD4gZK rDvvA59XFLCJ978lHKKngt2iaKf3f90k955si5r2iZahPIjkJNnt1y1GRg1hVrP8NwwI2cyrNxV q0N4yXSUlEdwbb42iJKH5aKp7AADnCwtFkCZ/W3qxfAyhlm3eVtV/60AuQS3lzjIXr+TYqy5CWC BFUrQdbfj9XMZMNWLwf4qTQqvZKxw+Pt2OUbDcndFIk5qB1yYq0dgaRpOrtgUPx9FAtsIGGKb+8 vkCknd986DS7deg== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 The setattr codepath is still using coarse-grained timestamps, even on multigrain filesystems. To fix this, we need to fetch the timestamp for ctime updates later, at the point where the assignment occurs in setattr_copy. On a multigrain inode, ignore the ia_ctime in the attrs, and always update the ctime to the current clock value. Update the atime and mtime with the same value (if needed) unless they are being set to other specific values, a'la utimes(). Note that we don't want to do this universally however, as some filesystems (e.g. most networked fs) want to do an explicit update elsewhere before updating the local inode. Reviewed-by: Darrick J. Wong Reviewed-by: Josef Bacik Reviewed-by: Jan Kara Signed-off-by: Jeff Layton --- fs/attr.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 46 insertions(+), 6 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index c04d19b58f12..3bcbc45708a3 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -271,6 +271,42 @@ int inode_newsize_ok(const struct inode *inode, loff_t= offset) } EXPORT_SYMBOL(inode_newsize_ok); =20 +/** + * setattr_copy_mgtime - update timestamps for mgtime inodes + * @inode: inode timestamps to be updated + * @attr: attrs for the update + * + * With multigrain timestamps, we need to take more care to prevent races + * when updating the ctime. Always update the ctime to the very latest + * using the standard mechanism, and use that to populate the atime and + * mtime appropriately (unless we're setting those to specific values). + */ +static void setattr_copy_mgtime(struct inode *inode, const struct iattr *a= ttr) +{ + unsigned int ia_valid =3D attr->ia_valid; + struct timespec64 now; + + /* + * If the ctime isn't being updated then nothing else should be + * either. + */ + if (!(ia_valid & ATTR_CTIME)) { + WARN_ON_ONCE(ia_valid & (ATTR_ATIME|ATTR_MTIME)); + return; + } + + now =3D inode_set_ctime_current(inode); + if (ia_valid & ATTR_ATIME_SET) + inode_set_atime_to_ts(inode, attr->ia_atime); + else if (ia_valid & ATTR_ATIME) + inode_set_atime_to_ts(inode, now); + + if (ia_valid & ATTR_MTIME_SET) + inode_set_mtime_to_ts(inode, attr->ia_mtime); + else if (ia_valid & ATTR_MTIME) + inode_set_mtime_to_ts(inode, now); +} + /** * setattr_copy - copy simple metadata updates into the generic inode * @idmap: idmap of the mount the inode was found from @@ -303,12 +339,6 @@ void setattr_copy(struct mnt_idmap *idmap, struct inod= e *inode, =20 i_uid_update(idmap, attr, inode); i_gid_update(idmap, attr, inode); - if (ia_valid & ATTR_ATIME) - inode_set_atime_to_ts(inode, attr->ia_atime); - if (ia_valid & ATTR_MTIME) - inode_set_mtime_to_ts(inode, attr->ia_mtime); - if (ia_valid & ATTR_CTIME) - inode_set_ctime_to_ts(inode, attr->ia_ctime); if (ia_valid & ATTR_MODE) { umode_t mode =3D attr->ia_mode; if (!in_group_or_capable(idmap, inode, @@ -316,6 +346,16 @@ void setattr_copy(struct mnt_idmap *idmap, struct inod= e *inode, mode &=3D ~S_ISGID; inode->i_mode =3D mode; } + + if (is_mgtime(inode)) + return setattr_copy_mgtime(inode, attr); + + if (ia_valid & ATTR_ATIME) + inode_set_atime_to_ts(inode, attr->ia_atime); + if (ia_valid & ATTR_MTIME) + inode_set_mtime_to_ts(inode, attr->ia_mtime); + if (ia_valid & ATTR_CTIME) + inode_set_ctime_to_ts(inode, attr->ia_ctime); } EXPORT_SYMBOL(setattr_copy); =20 --=20 2.46.0