From: John Hubbard <jhubbard@nvidia.com>
To: Souptick Joarder <jrdr.linux@gmail.com>, <takedakn@nttdata.co.jp>,
<penguin-kernel@I-love.SAKURA.ne.jp>, <jmorris@namei.org>,
<serge@hallyn.com>
Cc: <linux-security-module@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, Jan Kara <jack@suse.cz>,
Matthew Wilcox <willy@infradead.org>
Subject: Re: [PATCH 1/2] tomoyo: Convert get_user_pages*() to pin_user_pages*()
Date: Sat, 7 Nov 2020 11:17:52 -0800 [thread overview]
Message-ID: <e6859981-bc3c-9513-99e5-a99849786156@nvidia.com> (raw)
In-Reply-To: <e5401549-8c31-2c6d-58dd-864232de17af@nvidia.com>
On 11/7/20 1:04 AM, John Hubbard wrote:
> On 11/7/20 12:24 AM, Souptick Joarder wrote:
>> In 2019, we introduced pin_user_pages*() and now we are converting
>> get_user_pages*() to the new API as appropriate. [1] & [2] could
>> be referred for more information. This is case 5 as per document [1].
>
> It turns out that Case 5 can be implemented via a better pattern, as long
> as we're just dealing with a page at a time, briefly:
>
> lock_page()
> write to page's data
> unlock_page()
>
> ...which neatly synchronizes with writeback and other fs activities.
Ahem, I left out a key step: set_page_dirty()!
lock_page()
write to page's data
set_page_dirty()
unlock_page()
thanks,
--
John Hubbard
NVIDIA
next prev parent reply other threads:[~2020-11-07 19:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-07 8:24 Souptick Joarder
2020-11-07 8:24 ` [PATCH 2/2] tomoyo: Fixed typo in documentation Souptick Joarder
2020-11-07 8:57 ` John Hubbard
2020-11-09 3:41 ` Souptick Joarder
2020-11-09 4:17 ` John Hubbard
2020-11-07 9:04 ` [PATCH 1/2] tomoyo: Convert get_user_pages*() to pin_user_pages*() John Hubbard
2020-11-07 19:17 ` John Hubbard [this message]
2020-11-08 1:13 ` Tetsuo Handa
2020-11-08 2:17 ` John Hubbard
2020-11-08 4:12 ` Tetsuo Handa
2020-11-08 5:00 ` John Hubbard
2020-11-09 3:38 ` Souptick Joarder
2020-11-09 3:36 ` Souptick Joarder
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