From patchwork Mon Jul 1 10:26:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13717805 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 F076A14A605; Mon, 1 Jul 2024 10:27:10 +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=1719829631; cv=none; b=ot1PcnUQNRQF+ECUWYTgOPdd/hOREarXxdURjumiKZAcErfb0ZV2eAtp7DfVR4wAs5PRzxmZCC2DFDp5BSCtrPo15e/9K6KThacKl5IpprwdWfUqwT01czX0XQDTOQ1Dj5a8IaCFwg4C0xNLAtaD4u3X1IjvDnr4oLV/AtA0hT0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719829631; c=relaxed/simple; bh=ZBKByquYEdSc8HMPTmMqO17BDUigbAna6N8Jb8o7VIE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=rSydsjo5dTiERTbMQxVjfkUPBoJPkbEerrAx6lpS3qiiAxBVqVSNbf5MAMcIzxgQsdDvtqRt/mcyMUZnDxIQ93YllVTDEC0+3/9rcJSivMNQDpK/ZLD3wrP91hS7OXZj//LhWkaHUdBVfYOd8186Ptx0X0JRWj+Tk8/b9GXLLD4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fH62UWFL; 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="fH62UWFL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61429C4AF0F; Mon, 1 Jul 2024 10:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719829630; bh=ZBKByquYEdSc8HMPTmMqO17BDUigbAna6N8Jb8o7VIE=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=fH62UWFLV1muAZCZ9Uqg8bup5NTWlC8DFd1KVhJmlGrmNURVzr8eb8sA0Ls90voPR BbWcdY9SGonGUlyLLohh8+/QHnD9ygByoLBqltTBBsxFJG8QpTGWgi+DTFDv40qK2k FoaAfg3P+swSTgSp56VoeYVv3XfaKaaOmfXxmuqvBBmKFtikx+s7Yd0In339RLRYtH 5DvYLSg6Z+QQFmoaTW5xjJjLvLIoqs0qwKH0u2qrUxflf/dYxqRXZjdcX5xrYSNoD1 6Bu6MS8IxZDMSEHAo90bvmQWpynDEH0t3qJ5M+xLfvP0rnFo0ZTsCBL4UM5tjESSK3 UbDe+sB/rUbqA== From: Jeff Layton Date: Mon, 01 Jul 2024 06:26:37 -0400 Subject: [PATCH v2 01/11] fs: turn inode ctime fields into a single ktime_t Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240701-mgtime-v2-1-19d412a940d9@kernel.org> References: <20240701-mgtime-v2-0-19d412a940d9@kernel.org> In-Reply-To: <20240701-mgtime-v2-0-19d412a940d9@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 Cc: Andi Kleen , 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, Jeff Layton X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3344; i=jlayton@kernel.org; h=from:subject:message-id; bh=ZBKByquYEdSc8HMPTmMqO17BDUigbAna6N8Jb8o7VIE=; b=kA0DAAgBAA5oQRlWghUByyZiAGaChHij2CN1I/zkl//fedCXp9VjMU5Dtw3Kbn8GML+q0mPsf 4kCMwQAAQgAHRYhBEvA17JEcbKhhOr10wAOaEEZVoIVBQJmgoR4AAoJEAAOaEEZVoIVvDQQAMSY w7rzKxq0PvZZk5HYZj1Fd+MbtYtz2FqcFHuKdCL1wNI9qSIh5roycQHJdjwhp7tcgrSW076CBD8 tEJj4kkd46Nm7jKcMAy2Kv00LGcN29a5c5wnqj9AGRoTXpLf7C5tJBL31pKHj5ignjT4+59wlte o5ZuEo+Gm0ijd/j3es9lK7BIJMyMyFR3BDO5e7dg5rdhPOnt90Y8e9OjTkzc1rCeeVWeBCDDGcb 8LX8+xKrMExJonsClph8lXkxT5LrzJLbSIouBeBicEkm/xh5sbO0sV7fRuNPFZYm7CUyqJNnDJA /Olm4VSauOArxzOmuk+e6jPxboFFxHB7AuIWY1i8KcowJ1FQ4sIsGaqrJOiLnDyhrSeDIJAtOHf j2vthNwFYecOlAWDma4SRUfGpzuwd9Bxb1VZzZWUeL1PqOU+FIA81Wm88el2cdOV8SN4aH6ZcQF E1KZJsOwuDXw/FSgbgFifdijqi3jpaEfiyTiUfOSV/lh4GIYFpHc+1eHkgPOxYO2ty/NxZh35Z6 NJ/e1UPJRnNiFRMKHvPx16kwE4KAsvREDbAd3SRBhXkwBhw/aL1Sx7nYpQv9JENH+6dZeWBgTd9 INL5kJ3hGTS8vYlHAU/WeNNJlO44ASLpvswExclby6lH+tUv/o82oJAcjjfCPr/Y7ri/o+HSzLL 7WR8L X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 The ctime is not settable to arbitrary values. It always comes from the system clock, so we'll never stamp an inode with a value that can't be represented there. If we disregard people setting their system clock past the year 2262, there is no reason we can't replace the ctime fields with a ktime_t. Switch the ctime fields to a single ktime_t. Move the i_generation down above i_fsnotify_mask and then move the i_version into the resulting 8 byte hole. This shrinks struct inode by 8 bytes total, and should improve the cache footprint as the i_version and ctime are usually updated together. The one downside I can see to switching to a ktime_t is that if someone has a filesystem with files on it that has ctimes outside the ktime_t range (before ~1678 AD or after ~2262 AD), we won't be able to display them properly in stat() without some special treatment in the filesystem. The operating assumption here is that that is not a practical problem. Signed-off-by: Jeff Layton --- include/linux/fs.h | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/include/linux/fs.h b/include/linux/fs.h index 2fa06a4d197a..7110d6dc9aab 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -662,11 +662,10 @@ struct inode { loff_t i_size; time64_t i_atime_sec; time64_t i_mtime_sec; - time64_t i_ctime_sec; u32 i_atime_nsec; u32 i_mtime_nsec; - u32 i_ctime_nsec; - u32 i_generation; + ktime_t __i_ctime; + atomic64_t i_version; spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */ unsigned short i_bytes; u8 i_blkbits; @@ -701,7 +700,6 @@ struct inode { struct hlist_head i_dentry; struct rcu_head i_rcu; }; - atomic64_t i_version; atomic64_t i_sequence; /* see futex */ atomic_t i_count; atomic_t i_dio_count; @@ -724,6 +722,8 @@ struct inode { }; + u32 i_generation; + #ifdef CONFIG_FSNOTIFY __u32 i_fsnotify_mask; /* all events this inode cares about */ /* 32-bit hole reserved for expanding i_fsnotify_mask */ @@ -1608,29 +1608,25 @@ static inline struct timespec64 inode_set_mtime(struct inode *inode, return inode_set_mtime_to_ts(inode, ts); } -static inline time64_t inode_get_ctime_sec(const struct inode *inode) +static inline struct timespec64 inode_get_ctime(const struct inode *inode) { - return inode->i_ctime_sec; + return ktime_to_timespec64(inode->__i_ctime); } -static inline long inode_get_ctime_nsec(const struct inode *inode) +static inline time64_t inode_get_ctime_sec(const struct inode *inode) { - return inode->i_ctime_nsec; + return inode_get_ctime(inode).tv_sec; } -static inline struct timespec64 inode_get_ctime(const struct inode *inode) +static inline long inode_get_ctime_nsec(const struct inode *inode) { - struct timespec64 ts = { .tv_sec = inode_get_ctime_sec(inode), - .tv_nsec = inode_get_ctime_nsec(inode) }; - - return ts; + return inode_get_ctime(inode).tv_nsec; } static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode, struct timespec64 ts) { - inode->i_ctime_sec = ts.tv_sec; - inode->i_ctime_nsec = ts.tv_nsec; + inode->__i_ctime = ktime_set(ts.tv_sec, ts.tv_nsec); return ts; }