From mboxrd@z Thu Jan 1 00:00:00 1970 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 76F221B1D7D for ; Fri, 30 Aug 2024 14:04:42 +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=1725026682; cv=none; b=dTXMmHPIorZOnR4ZIH3ISh8WDYvi/d/lAwkZdEY/WbSf1+umdmDnHGMXEFyIBQo98IPRCxBFW4wL8SikGv3e7Fmv6/AG9bc4uO1fP1Zvr7dzMZazzZXkceJA7MTTPeLBQWtQcqCPP7p2znhxLesZ92n+3XGXHgbi5SsMOEOuJPc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725026682; c=relaxed/simple; bh=L3qZxkfAM9sP4M5Q3Qr4itjjlJSJx9il0VGnHrdMS+I=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=qDRZHWmmkps2PIGQAavuKn3q8y49GnQY8gaXOr0S5lhRh5N5IuDQ3UCwsb6ty84iX8c4THn9RL6PqqkgTHzM9tXRnAZsmVOlFqC5Ty9F2vo5VY/r/iM1O9mtiODSpk3ffm2UTLaNgmfNI9PLkGpvbbwrKSPTA9XiznOoVZCRauk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OPw/Vb8c; 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="OPw/Vb8c" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43ADEC4CEC7; Fri, 30 Aug 2024 14:04:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1725026681; bh=L3qZxkfAM9sP4M5Q3Qr4itjjlJSJx9il0VGnHrdMS+I=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=OPw/Vb8cGkziM6i1Ez6QiNNVNa2CgC5hlYeaX5/OeQE/wYx56I/K1aarHClOV3Z+r QLPivQ6qDjZ3gVihWsQM70tx7zjMhcfFrRcA1djkoUGevfjcjfoqkvAGp+HqZTpDCa zgJILLF3X6vVYJU6Q1XMboXJlBC1xiVF/anfut4egGetPXA6EVv7JSNGhvB+p9/2Qu 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member in struct file isn't particularly well-defined. It > is mainly used as a cookie to detect concurrent seeks when iterating > directories. But it is also abused by some subsystems for completely > unrelated things. >=20 > It is mostly a directory specific thing that doesn't really need to live > in struct file and with its wonky semantics it really lacks a specific > function. >=20 > For pipes, f_version is (ab)used to defer poll notifications until a > write has happened. And struct pipe_inode_info is used by multiple > struct files in their ->private_data so there's no chance of pushing > that down into file->private_data without introducing another pointer > indirection. >=20 > But this should be a solvable problem. Only regular files with > FMODE_ATOMIC_POS and directories require f_pos_lock. Pipes and other > files don't. So this adds a union into struct file encompassing > f_pos_lock and a pipe specific f_pipe member that pipes can use. This > union of course can be extended to other file types and is similar to > what we do in struct inode already. >=20 > I hope I got the details right. It at least holds up in xfstests and LTP > and my hand-rolled getdents-seek stressor. > =20 >=20 > Signed-off-by: Christian Brauner > --- > Christian Brauner (20): > file: remove pointless comment > adi: remove unused f_version > ceph: remove unused f_version > s390: remove unused f_version > fs: add vfs_setpos_cookie() > fs: add must_set_pos() > fs: use must_set_pos() > fs: add generic_llseek_cookie() > affs: store cookie in private data > ext2: store cookie in private data > ext4: store cookie in private data > input: remove f_version abuse > ocfs2: store cookie in private data > proc: store cookie in private data > udf: store cookie in private data > ufs: store cookie in private data > ubifs: store cookie in private data > fs: add f_pipe > pipe: use f_pipe > fs: remove f_version >=20 > drivers/char/adi.c | 1 - > drivers/input/input.c | 8 +- > drivers/s390/char/hmcdrv_dev.c | 3 - > fs/affs/dir.c | 44 +++++++++-- > fs/ceph/dir.c | 1 - > fs/ext2/dir.c | 28 ++++++- > fs/ext4/dir.c | 50 ++++++------ > fs/ext4/ext4.h | 2 + > fs/ext4/inline.c | 7 +- > fs/file_table.c | 1 - > fs/ocfs2/dir.c | 3 +- > fs/ocfs2/file.c | 11 ++- > fs/ocfs2/file.h | 1 + > fs/pipe.c | 6 +- > fs/proc/base.c | 18 +++-- > fs/read_write.c | 169 +++++++++++++++++++++++++++++++----= ------ > fs/ubifs/dir.c | 65 +++++++++++----- > fs/udf/dir.c | 28 ++++++- > fs/ufs/dir.c | 28 ++++++- > include/linux/fs.h | 14 +++- > 20 files changed, 366 insertions(+), 122 deletions(-) > --- > base-commit: 79868ff5ce9156228f9aef351d8bf76fb8540230 > change-id: 20240829-vfs-file-f_version-66321e3dafeb >=20 I like it! Fairly straightforward, and it's good to see f_version (which has always been poorly defined) go away. Reviewed-by: Jeff Layton