From patchwork Thu Jun 27 01:00:21 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13713719 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 B8B49D299; Thu, 27 Jun 2024 01:00:36 +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=1719450036; cv=none; b=cDGFIRmO1YJI3WNXQkOLh8znnfBy7EodGlv3mOADFVAa+SegsuNy4lquDEoiUJRhSnytehWhSIDUzxF5t8NP3ai+ZxivE19tc6T45249PA2Aycy1ykWmCt08VuaTTuzf4Y1pF9Y5sCbCOzo1QKhKg0UcF6onkxDJeznaX35OLhw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719450036; c=relaxed/simple; bh=G1sIrGm75KvOwnRqj2Qr6NVY9492uXV9G5iKNcaenQ4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=nV7R7hJPUS+4x3MoLMfa5fEyEpL58GO+/fVPs7Ihk6MkYJ4wrEvq4UW8UZ4MOfXVIkHesVnDr+xd71hUsn8MDxpCCTheo8E5LkP7kyZgTEtbv7+K0XpBIHuDzFteoh/PyB/kRMcM7QvLLkaec9eA+TzremttYWeJkU5cE8v38no= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uu9bKpll; 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="uu9bKpll" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4AE4CC4AF07; Thu, 27 Jun 2024 01:00:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719450036; bh=G1sIrGm75KvOwnRqj2Qr6NVY9492uXV9G5iKNcaenQ4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=uu9bKpllUfrdSsygooj3Il3q8igpsvcmeAJH22XWhg0c7R4ESyKAy6ypVts8fty9Q A4rOJR86fnWgQq6PivWKbjaJlnw70+VkTI7DxzP60N2Qrir9Ic2bnuGZY/Mn3Kmx5Y 5O2ksEpKXnGnV02Ipp03xM+6wdkL/rOB0LvOe1tMB76udcWzWHkFgREjMAvwSO8liD 62ifGHWLFKbFpThGH6t5XGg0SqzlkqAPGYdd97REc6rKf9Shq9XTLEajv6JPfzo53X Uxs4hQ1uF5VqaGNENGK+CE6KwJhtX1VVXAPDIijDBZZ6duDZxgFvzxWTznJk0QMxVs KZor/o/3gWLEQ== From: Jeff Layton Date: Wed, 26 Jun 2024 21:00:21 -0400 Subject: [PATCH 01/10] fs: turn inode ctime fields into a single ktime_t Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240626-mgtime-v1-1-a189352d0f8f@kernel.org> References: <20240626-mgtime-v1-0-a189352d0f8f@kernel.org> In-Reply-To: <20240626-mgtime-v1-0-a189352d0f8f@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: 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=G1sIrGm75KvOwnRqj2Qr6NVY9492uXV9G5iKNcaenQ4=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBmfLmuOgyuFN9FzwPSoACp7/4FgL4U5ewrxzQPi h6LGQNjmoCJAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZny5rgAKCRAADmhBGVaC FX5ZEACvzw0eK1vFpOnF4nZM3s2zL0NqyeFfw2IuIbYubO0XzKfU/GlcdGAVZD1/oDZDN9X2Ntx tkSoujXFDXsMigQyoXVvDfxIpYSjogrB25YHg+5iMFM+/GLPQhReln8cY/xzbjx01IVuO0RXKE4 QCqFhVlV/I1AzaZ+xC2NOv8CXa/Gf1nSyV1llrK8t0wQT048zrREZqwJy2evRRRJ3ecwRRPh4cl IEJsjenGZNFF5pqNreGFh5eywBPrseN4m29EXntKoztrVnT8HM9FGHWXYI90hiugYxhtyUMLBl9 k7VrSVP5poWdnKgzfthiYN1qmCk4JMEVj0HsIcRPmQi+9kO9CtqDiWvTjKnLsTrNgCcvxWA7s3J fvxvlclGfrgwuT45eja71AqaiM3GYchiM0VjQebvZ8xZXFmqYsti088EqvJ+wjJH9xJgv9zRC66 G9eLzUdSnUckzPOx0BwcdvqOXD8/Dj2hrMXaC/2odyLZwF8XteERYsiPxnY88U2mWd5XGSXAouK D7d0B/OWH5OAovkc6IwLogJExZW8lY8ce4ubLrVbK8TVE5J1NsCvk2Jtj1jsTPlg/8qmVIWjqTz hfSDMcxZZ7/Njq2slc2PrWO+jzycNYolqZgeqH2NlccufsMKSRU4NLkED1LWFh8ynH9T1lR1mMw YmEPaOvwMbs8P+g== 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 5ff362277834..5139dec085f2 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; }