From: Al Viro <viro@zeniv.linux.org.uk>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-kernel@vger.kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Song Liu <song@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 17/23] initramfs: switch initramfs unpacking to struct file based APIs
Date: Mon, 27 Jul 2020 03:55:07 +0100 [thread overview]
Message-ID: <20200727025507.GC795125@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20200714190427.4332-18-hch@lst.de>
On Tue, Jul 14, 2020 at 09:04:21PM +0200, Christoph Hellwig wrote:
> - ssize_t rv = ksys_write(fd, p, count);
> + ssize_t rv = kernel_write(file, p, count, &file->f_pos);
No. Sure, that'll work for ramfs with nobody else playing with those.
However, this is the wrong way to do such things; do *NOT* pass the
address of file->f_pos to anything. The few places that still do that
are wrong.
As a general rule, ->read() and ->write() instances should never be
given &file->f_pos. Address of a local variable - sure, no problem.
Copy it back into ->f_pos when they are done? Also fine. But not
this,
Keep that offset in a variable (static in file, argument of xwrite(),
whatever).
next prev parent reply other threads:[~2020-07-27 2:55 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 19:04 decruft the early init / initrd / initramfs code v2 Christoph Hellwig
2020-07-14 19:04 ` [PATCH 01/23] fs: add a vfs_fchown helper Christoph Hellwig
2020-07-14 19:04 ` [PATCH 02/23] fs: add a vfs_fchmod helper Christoph Hellwig
2020-07-14 19:04 ` [PATCH 03/23] init: remove the bstat helper Christoph Hellwig
2020-07-15 23:14 ` NeilBrown
2020-07-14 19:04 ` [PATCH 04/23] md: move the early init autodetect code to drivers/md/ Christoph Hellwig
2020-07-14 19:04 ` [PATCH 05/23] md: replace the RAID_AUTORUN ioctl with a direct function call Christoph Hellwig
2020-07-15 23:33 ` NeilBrown
2020-07-14 19:04 ` [PATCH 06/23] md: remove the autoscan partition re-read Christoph Hellwig
2020-07-15 23:34 ` NeilBrown
2020-07-14 19:04 ` [PATCH 07/23] md: remove the kernel version of md_u.h Christoph Hellwig
2020-07-14 19:04 ` [PATCH 08/23] md: simplify md_setup_drive Christoph Hellwig
2020-07-15 23:37 ` NeilBrown
2020-07-14 19:04 ` [PATCH 09/23] md: rewrite md_setup_drive to avoid ioctls Christoph Hellwig
2020-07-15 23:50 ` NeilBrown
2020-07-16 13:38 ` Christoph Hellwig
2020-07-14 19:04 ` [PATCH 10/23] initrd: remove support for multiple floppies Christoph Hellwig
2020-07-14 19:04 ` [PATCH 11/23] initrd: remove the BLKFLSBUF call in handle_initrd Christoph Hellwig
2020-07-14 19:04 ` [PATCH 12/23] initrd: switch initrd loading to struct file based APIs Christoph Hellwig
2020-07-27 1:50 ` Al Viro
2020-07-14 19:04 ` [PATCH 13/23] initrd: mark init_linuxrc as __init Christoph Hellwig
2020-07-14 19:04 ` [PATCH 14/23] initrd: mark initrd support as deprecated Christoph Hellwig
2020-07-14 19:04 ` [PATCH 15/23] initramfs: remove the populate_initrd_image and clean_rootfs stubs Christoph Hellwig
2020-07-14 19:04 ` [PATCH 16/23] initramfs: simplify clean_rootfs Christoph Hellwig
[not found] ` <CGME20200717205549eucas1p13fca9a8496836faa71df515524743648@eucas1p1.samsung.com>
2020-07-17 20:55 ` Marek Szyprowski
2020-07-18 10:00 ` Christoph Hellwig
2020-07-23 9:22 ` Christoph Hellwig
2020-07-23 14:25 ` Lukasz Stelmach
2020-07-23 14:27 ` Christoph Hellwig
2020-07-27 2:41 ` Al Viro
2020-07-27 2:44 ` Matthew Wilcox
2020-07-14 19:04 ` [PATCH 17/23] initramfs: switch initramfs unpacking to struct file based APIs Christoph Hellwig
2020-07-14 19:31 ` Linus Torvalds
2020-07-15 6:27 ` Christoph Hellwig
2020-07-27 2:55 ` Al Viro [this message]
2020-07-14 19:04 ` [PATCH 18/23] init: open code setting up stdin/stdout/stderr Christoph Hellwig
2020-07-27 3:05 ` Al Viro
2020-07-27 5:46 ` Christoph Hellwig
2020-07-27 6:03 ` Al Viro
2020-07-27 6:48 ` Christoph Hellwig
2020-07-27 15:54 ` Al Viro
2020-07-27 15:58 ` Christoph Hellwig
2020-07-27 6:20 ` hpa
2020-07-27 6:24 ` Christoph Hellwig
2020-07-27 6:36 ` hpa
2020-07-27 6:49 ` Christoph Hellwig
2020-07-14 19:04 ` [PATCH 19/23] fs: remove ksys_getdents64 Christoph Hellwig
2020-07-14 19:04 ` [PATCH 20/23] fs: remove ksys_open Christoph Hellwig
2020-07-14 19:04 ` [PATCH 21/23] fs: remove ksys_dup Christoph Hellwig
2020-07-14 19:04 ` [PATCH 22/23] fs: remove ksys_fchmod Christoph Hellwig
2020-07-14 19:04 ` [PATCH 23/23] fs: remove ksys_ioctl Christoph Hellwig
2020-07-14 19:34 ` decruft the early init / initrd / initramfs code v2 Linus Torvalds
2020-07-15 6:51 ` Christoph Hellwig
2020-07-16 15:57 ` Guoqing Jiang
2020-07-16 16:00 ` Christoph Hellwig
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