From patchwork Thu Jul 11 11:08:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13730442 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 7017815E5CA; Thu, 11 Jul 2024 11:08:37 +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=1720696117; cv=none; b=jkgKt+jWCEYkoPKzikvN/j2rprYjR/FkC7sH411hdjrfteeTsHckJzCDr4v1LVi19s6FlcnAgHqkMcMX6WBk8zX3OhXJS7cGMy8gtzp9T3iqlCbyLcTj6C4Nu0spWTDXLNT5eDiF2KSOcpIaOpZjjb191B+/m6zFl2wxPEqxFgE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720696117; c=relaxed/simple; bh=/g1ddIto05q7VUdUuGmHZRulUXiGWzaifPHAIEfpWmk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=HeBmJFXiiBnUnyuinXhPNwFX7jtp4Wyw1lQOO5dCBo0sllRBDNSd3DjvJn0wXbwu8pYjvEKsgS58jTg32Dmweyni0uTFrbr93CZfx67PzhDVmQaPBldf/uJolg9sEnIBEAJZKFgNh8ZAPA8MwSNsUxtGdBtNh69Y+B2xL8OxoQk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aM6rnkQn; 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="aM6rnkQn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3ED33C4AF0F; Thu, 11 Jul 2024 11:08:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720696117; bh=/g1ddIto05q7VUdUuGmHZRulUXiGWzaifPHAIEfpWmk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=aM6rnkQnft67EwdDPveBEC+aLnbaz9Iw/J9cEyYCG3WskFlIH9k0egFU0+Qi2Q05c PGTgq5xVMimnrOH/NEwwdPJJxHGQC59lahoqxdR1589/Od69pfsq/S4P9rCm6EDfnE CCbH8QPfqjRO2bzt1m/KEINTRYYAeM41mPxo/nmz0cf7H3iakPlLS6s8HITwbeYPU+ i2/lDosNupJCDwHLlMu9LzEE4CucQJZFqhDTVII8U+QLk+uhFR97875JWbKdeb8kEY m6RUPbotcrmnFL7PG2S+dR12jKaQ79i/hUeM6l9cFRvMyW7Ub2xHxlN/HxyaaoQOIU tNrQX0xPxYWJw== From: Jeff Layton Date: Thu, 11 Jul 2024 07:08:08 -0400 Subject: [PATCH v5 4/9] fs: have setattr_copy handle multigrain timestamps appropriately Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240711-mgtime-v5-4-37bb5b465feb@kernel.org> References: <20240711-mgtime-v5-0-37bb5b465feb@kernel.org> In-Reply-To: <20240711-mgtime-v5-0-37bb5b465feb@kernel.org> To: Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Chandan Babu R , "Darrick J. Wong" , Theodore Ts'o , Andreas Dilger , Chris Mason , Josef Bacik , David Sterba , Hugh Dickins , Andrew Morton , Jonathan Corbet Cc: Dave Chinner , Andi Kleen , Christoph Hellwig , Uros Bizjak , Kent Overstreet , Arnd Bergmann , Randy Dunlap , kernel-team@fb.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-doc@vger.kernel.org, Jeff Layton X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3403; i=jlayton@kernel.org; h=from:subject:message-id; bh=/g1ddIto05q7VUdUuGmHZRulUXiGWzaifPHAIEfpWmk=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBmj70l0tB8wkk1mE/fQzmfxmASsaLYnQ6xULsvM medg6N9UiyJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZo+9JQAKCRAADmhBGVaC FRj/D/9/qFMGv96YIkAUDVx329NA3lwGZlqp79bN1JG78zGjqY7RX8Uv8c805I25dhpqy2+jfBk VnWd2HCtg1ShenHgPEfnBAsQNjiSUqeF1uIuEVVrTwFaq8AsGY8LTu0QVyeuGImLKtdQomtuVwt FSmNefB0eXDRt6rmOFfnflJoXglp10hyeikatMaHGEr4ASXHDObg50snibOl81qye5cNJh6LbWT UZSgieB+TtqZzZfxAqwNVBRXLrT8QjDcSyfNuJoiB16Jnejn5qaFVEiGGqomR3//RmFSBozZ16y 1HwtgYp+Wn/io/r+6kKUrUeYHURFsR2sVu7s/XBzTb6gJ3yMjd8YTaCSg8Oy+yKNh32pf39Lhmh arf0zK8/W8lt2iOWSuLYJ2//NzoH8u/p12GqCm2dhWvmIWg1CD7YqW3cDGiWc8bltkudb+doVt7 JnP52FRHLAy8v3Sbp5QD9WLr/4lBVDEaE+ulNhzfxNjI6XIaMRQLWY83t1qsaNRRd9+l/QdIh4D w8GSkDpmq9M+iIPOmGLF2GndPggmO3X5p84sFpQHkNa9P8Nc+DBt0RnoIS+1FTm4LfAs3VrB9Se XHTcE4rfgHM0uGMDzvP3iybkgvcTipYHi9n9zPYC1UflB4CkmguObxvjJKWVAOuSCGxvMhtPjBt g4r/yhDL2VECz9A== 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. Signed-off-by: Jeff Layton Reviewed-by: Darrick J. Wong --- fs/attr.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 46 insertions(+), 6 deletions(-) diff --git a/fs/attr.c b/fs/attr.c index 825007d5cda4..e03ea6951864 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); +/** + * 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 *attr) +{ + unsigned int ia_valid = 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 = 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 inode *inode, 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 = attr->ia_mode; if (!in_group_or_capable(idmap, inode, @@ -316,6 +346,16 @@ void setattr_copy(struct mnt_idmap *idmap, struct inode *inode, mode &= ~S_ISGID; inode->i_mode = 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);