From: Alexander Lochmann <alexander.lochmann@tu-dortmund.de>
To: Jan Kara <jack@suse.cz>
Cc: "Theodore Ts'o" <tytso@mit.edu>,
Horst Schirmeier <horst.schirmeier@tu-dortmund.de>,
Jan Kara <jack@suse.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC] inode.i_opflags - Usage of two different locking schemes
Date: Fri, 26 Mar 2021 17:37:34 +0100 [thread overview]
Message-ID: <0e308673-a350-98af-b0a7-cde63abd4579@tu-dortmund.de> (raw)
In-Reply-To: <20210316171429.GA22701@quack2.suse.cz>
On 16.03.21 18:14, Jan Kara wrote:
>
> So i_lock is supposed to protect i_opflags for writing AFAICT. For reading
> we don't seem to bother in some cases and I agree that is potentially
> problematic. It is *mostly* OK because we initialize i_opflags when loading
> inode into memory / adding it to dcache. But sometimes we also update them
> while the inode is alive. Now this is fine for the particular flag we
> update but in theory, if the compiler wants to screw us and stores
> temporarily some nonsensical value in i_opflags we'd have a problem. This
> is mostly a theoretical issue but eventually we probably want to fix this.
>
> Honza
>
Thx for the detailed explanation. :-)
- Alex
--
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Alexander Lochmann PGP key: 0xBC3EF6FD
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prev parent reply other threads:[~2021-03-26 16:38 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <f63dd495-defb-adc4-aa91-6aacd7f441c7@tu-dortmund.de>
2021-03-05 13:10 ` [RFC] inode.i_opflags - Usage of two different locking schemes Alexander Lochmann
2021-03-05 15:18 ` Theodore Ts'o
2021-03-05 15:35 ` Alexander Lochmann
2021-03-05 16:04 ` Theodore Ts'o
2021-03-08 14:05 ` Alexander Lochmann
2021-03-16 17:14 ` Jan Kara
2021-03-26 16:37 ` Alexander Lochmann [this message]
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