linux-kernel - Re: POSIX violation by writeback error

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Message-ID: <20180904162348.GN17123@BitWizard.nl>
Date:   Tue, 4 Sep 2018 18:23:48 +0200
From:   Rogier Wolff <R.E.Wolff@...Wizard.nl>
To:     "J. Bruce Fields" <bfields@...ldses.org>
Cc:     Jeff Layton <jlayton@...hat.com>,
        焦晓冬 <milestonejxd@...il.com>,
        linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: POSIX violation by writeback error

On Tue, Sep 04, 2018 at 12:12:03PM -0400, J. Bruce Fields wrote:

> 
> Well, I think the point was that in the above examples you'd prefer that
> the read just fail--no need to keep the data.  A bit marking the file
> (or even the entire filesystem) unreadable would satisfy posix, I guess.
> Whether that's practical, I don't know.

When you would do it like that (mark the whole filesystem as "in
error") things go from bad to worse even faster. The Linux kernel 
tries to keep the system up even in the face of errors. 

With that suggestion, having one application run into a writeback
error would effectively crash the whole system because the filesystem
may be the root filesystem and stuff like "sshd" that you need to
diagnose the problem needs to be read from the disk.... 

	Roger. 

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