From: "Colin Walters" <walters@verbum.org>
To: "Dave Chinner" <david@fromorbit.com>, "Jann Horn" <jannh@google.com>
Cc: "Omar Sandoval" <osandov@osandov.com>,
"Aleksa Sarai" <cyphar@cyphar.com>,
"Jens Axboe" <axboe@kernel.dk>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-btrfs@vger.kernel.org,
"Linux API" <linux-api@vger.kernel.org>,
"Kernel Team" <kernel-team@fb.com>,
"Andy Lutomirski" <luto@kernel.org>
Subject: Re: [RFC PATCH 2/3] fs: add RWF_ENCODED for writing compressed data
Date: Wed, 25 Sep 2019 08:07:12 -0400 [thread overview]
Message-ID: <60c48ac5-b215-44e1-a628-6145d84a4ce3@www.fastmail.com> (raw)
In-Reply-To: <20190925071129.GB804@dread.disaster.area>
On Wed, Sep 25, 2019, at 3:11 AM, Dave Chinner wrote:
>
> We're talking about user data read/write access here, not some
> special security capability. Access to the data has already been
> permission checked, so why should the format that the data is
> supplied to the kernel in suddenly require new privilege checks?
What happens with BTRFS today if userspace provides invalid compressed data via this interface? Does that show up as filesystem corruption later? If the data is verified at write time, wouldn't that be losing most of the speed advantages of providing pre-compressed data?
Ability for a user to cause fsck errors later would be a new thing that would argue for a privilege check I think.
next prev parent reply other threads:[~2019-09-25 12:07 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-19 6:53 [RFC PATCH 0/3] fs: interface for directly writing encoded (e.g., compressed) data Omar Sandoval
2019-09-19 6:53 ` [RFC PATCH 1/3] fs: pass READ/WRITE to kiocb_set_rw_flags() Omar Sandoval
2019-09-20 14:38 ` Jan Kara
2019-09-19 6:53 ` [PATCH] readv.2: Document new RWF_ENCODED flag to pwritev2() Omar Sandoval
2019-09-19 6:53 ` [RFC PATCH 2/3] fs: add RWF_ENCODED for writing compressed data Omar Sandoval
2019-09-19 15:44 ` Jann Horn
2019-09-20 16:25 ` Jens Axboe
2019-09-24 17:15 ` Omar Sandoval
2019-09-24 19:35 ` Omar Sandoval
2019-09-24 20:01 ` Jann Horn
2019-09-24 20:22 ` Christian Brauner
2019-09-24 20:50 ` Matthew Wilcox
2019-09-24 20:38 ` Omar Sandoval
2019-09-25 7:11 ` Dave Chinner
2019-09-25 12:07 ` Colin Walters [this message]
2019-09-25 14:56 ` [RFC PATCH 2/3] " Chris Mason
2019-09-26 12:17 ` Colin Walters
2019-09-26 17:46 ` Omar Sandoval
2019-09-25 15:08 ` [RFC PATCH 2/3] fs: " Theodore Y. Ts'o
2019-09-25 22:52 ` Dave Chinner
2019-09-26 0:36 ` Omar Sandoval
2019-09-19 6:53 ` [RFC PATCH 3/3] btrfs: implement encoded (compressed) writes Omar Sandoval
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