From patchwork Tue Oct 1 10:58:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Layton X-Patchwork-Id: 13817845 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 272E81BF305; Tue, 1 Oct 2024 10:59:19 +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=1727780359; cv=none; b=hkEPSEt2ipatFsFmEFn2w8bIp4iBvty0AX2BWHQqff0+ba4GC2HygQ6UOoHJ3pLiEFeqwzvZfyOyYppCBKq3MEkUROsa5WT7dCXaa8x+Xpkjsed/H2iwH2ulqr8uDI9jvmXdajQ3qljZXV83AlVwI7+VAJG1TweOWQTl66cUq5k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727780359; c=relaxed/simple; bh=IlK6pMQl1VZaRTQUEj0w67Ch4gWJlIpgXXZruOpOJpc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Nca1RnKD0Y0T+UDtoSp6YyV94i4Ta/RZDGDrLamsHQiSCDTvBaLLmmd5c2gJvNXu/vGhfNg51liLM9SJ397w8kQSSke63uEIdm+ABe9vdmFSYgdbzeJygwZh4sgXO6aBguaPnY/feZzji7xZOfe+LRnjVUtLefQLlEjt6AnzRRA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jdWGxNnl; 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="jdWGxNnl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64621C4CED4; Tue, 1 Oct 2024 10:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1727780358; bh=IlK6pMQl1VZaRTQUEj0w67Ch4gWJlIpgXXZruOpOJpc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=jdWGxNnlxMwS3+6yjpiIb4x86c6Y3TIErGhniYiNJEOlBFtaxtSGyGJt+YG5JfF5f Co1d4yP95nQF48Y/dcoyaN9DwQBiAFu65Q0MGvTNlhACrPKqHrmzHIAABtrJz47+Fw 3jm3yyjCpgoEKgki1HQlYZFsxXrxk8jaNcgNtoRRRGLXZCym4pKWd8+zTdVtwDO6x6 94owkToMnnnb7OJ5AxGK2IsD08ngJDcukm/REUzkRh1mhDiXycOKyXO67/ReZ60dMa bDAWfvx38Ki4Gisf95iOtoLVvJ5cvcqpxn6qTV2WmySIld5q86F3P4s4KSPwK9/a7C 0phOrYwm4fXmg== From: Jeff Layton Date: Tue, 01 Oct 2024 06:58:57 -0400 Subject: [PATCH v8 03/12] 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: <20241001-mgtime-v8-3-903343d91bc3@kernel.org> References: <20241001-mgtime-v8-0-903343d91bc3@kernel.org> In-Reply-To: <20241001-mgtime-v8-0-903343d91bc3@kernel.org> To: John Stultz , Thomas Gleixner , Stephen Boyd , Alexander Viro , Christian Brauner , Jan Kara , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Randy Dunlap , 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: 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=3610; i=jlayton@kernel.org; h=from:subject:message-id; bh=IlK6pMQl1VZaRTQUEj0w67Ch4gWJlIpgXXZruOpOJpc=; b=owEBbQKS/ZANAwAIAQAOaEEZVoIVAcsmYgBm+9X5YIAUQIyeGlbkZz0C3Ucs84y+6R8LaUnqt K6DgFg2Ba6JAjMEAAEIAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCZvvV+QAKCRAADmhBGVaC FUcAD/9+TpkoTJObmH1PTrMTi9b6fcDncKerKYhSvomtiUjooe9rP/Z43xb4vfBPHr+mdv9BMDk vMyzIlNK4KZJczt626wn0uV7YrtEHK4SbfNP87PPyZpGztVypqDRAKlx+F5+brwhkYFacDgOiHb WWj6/5oN+zfWHwoMYoa7MuCyf65x1tipBW992ENarxxcFfvFXMeEX2HyJSwu/xlDSQlObSu562a 2GqqvYxaIyJOApO1L4X3rYAoH64xrsCaXWR+4yub4SVu/T3kLXA9K4OxTtJDTnFF1K2Vc+jJEgF 91PqQ61OrRHOuI2CeuSP+K66j/Bo+7/MuDZVhTbRPUTUbaio8MVXLyc0Ak4Q1Nwq1AsPSQPZGba I7htvHUy7c2gRCSoY+tbesZaCesFgqvjRD64fzIy6QNUNb1tfdfEbswaX4cbp2xRZd6mcB52Y0S 4KA63naImLEGCVt+sEGX23x7sv/d1LsFbl/5FlJnIsx/XYNr1Zcb4MwnohlwMTZOFGRge2BXO1Y LxXZ+rUZPw3WDGnO9ONYeKb4juvJy2C1Psgq1Sb5RbG947cVEhpsoVUd6j6EBpXLWIP1RrTcomR a840JJBQ7phKKl3uGoFB/BWexhtYGZCe9RWI79hcjdxdHDq2Kd0JKKT177yuKkshdKXvQpfvVSC kV8NlS8NDSS/E2A== 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 Tested-by: Randy Dunlap # documentation bits 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); +/** + * 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);