From: Rogier Wolff <R.E.Wolff@BitWizard.nl>
To: 焦晓冬 <milestonejxd@gmail.com>
Cc: jlayton@redhat.com, linux-fsdevel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: POSIX violation by writeback error
Date: Tue, 4 Sep 2018 09:53:47 +0200 [thread overview]
Message-ID: <20180904075347.GH11854@BitWizard.nl> (raw)
In-Reply-To: <CAJDTihz-rFb2SGaxZsQnXGnee_2qW_ynhPe=tZ4yzQBSV_KQ1g@mail.gmail.com>
On Tue, Sep 04, 2018 at 02:32:28PM +0800, 焦晓冬 wrote:
> Hi,
>
> After reading several writeback error handling articles from LWN, I
> begin to be upset about writeback error handling.
>
> Jlayton's patch is simple but wonderful idea towards correct error
> reporting. It seems one crucial thing is still here to be fixed. Does
> anyone have some idea?
>
> The crucial thing may be that a read() after a successful
> open()-write()-close() may return old data.
>
> That may happen where an async writeback error occurs after close()
> and the inode/mapping get evicted before read().
Suppose I have 1Gb of RAM. Suppose I open a file, write 0.5Gb to it
and then close it. Then I repeat this 9 times.
Now, when writing those files to storage fails, there is 5Gb of data
to remember and only 1Gb of RAM.
I can choose any part of that 5Gb and try to read it.
Please make a suggestion about where we should store that data?
In the easy case, where the data easily fits in RAM, you COULD write a
solution. But when the hardware fails, the SYSTEM will not be able to
follow the posix rules.
Roger.
--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 **
** Delftechpark 26 2628 XH Delft, The Netherlands. KVK: 27239233 **
*-- BitWizard writes Linux device drivers for any device you may have! --*
The plan was simple, like my brother-in-law Phil. But unlike
Phil, this plan just might work.
next prev parent reply other threads:[~2018-09-04 7:53 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-04 6:32 POSIX violation by writeback error 焦晓冬
2018-09-04 7:53 ` Rogier Wolff [this message]
2018-09-04 8:58 ` 焦晓冬
2018-09-04 9:29 ` Rogier Wolff
2018-09-04 10:45 ` 焦晓冬
2018-09-04 11:09 ` Jeff Layton
2018-09-04 14:56 ` 焦晓冬
2018-09-04 15:44 ` Jeff Layton
2018-09-04 16:12 ` J. Bruce Fields
2018-09-04 16:23 ` Rogier Wolff
2018-09-04 18:54 ` J. Bruce Fields
2018-09-04 20:18 ` Jeff Layton
2018-09-04 20:35 ` Vito Caputo
2018-09-04 21:02 ` Matthew Wilcox
2018-09-05 0:51 ` Dave Chinner
2018-09-05 8:24 ` 焦晓冬
2018-09-05 10:55 ` Jeff Layton
2018-09-05 12:07 ` Rogier Wolff
2018-09-06 2:57 ` Dave Chinner
2018-09-06 9:17 ` Rogier Wolff
2018-09-24 23:09 ` Alan Cox
2018-09-05 13:53 ` J. Bruce Fields
2018-09-05 7:08 ` Rogier Wolff
2018-09-05 7:39 ` Martin Steigerwald
2018-09-05 8:04 ` Rogier Wolff
2018-09-05 8:37 ` 焦晓冬
2018-09-05 12:07 ` Austin S. Hemmelgarn
2018-09-05 12:46 ` Rogier Wolff
2018-09-05 9:32 ` Martin Steigerwald
2018-09-05 7:37 ` Martin Steigerwald
2018-09-05 11:42 ` Jeff Layton
2018-09-05 8:09 ` 焦晓冬
2018-09-05 13:08 ` Theodore Y. Ts'o
2018-09-24 23:21 ` Alan Cox
2018-09-06 7:28 ` 焦晓冬
[not found] <CAJDTihx2yaR-_-9Ks1PoFcrKNZgUOoLdN-wRTTMV76Jg_dCLrw@mail.gmail.com>
2018-09-04 10:56 ` Jeff Layton
2018-09-24 23:30 ` Alan Cox
2018-09-25 11:15 ` Jeff Layton
2018-09-25 15:46 ` Theodore Y. Ts'o
2018-09-25 16:17 ` Rogier Wolff
2018-09-25 16:39 ` Alan Cox
2018-09-25 16:41 ` Jeff Layton
2018-09-25 22:30 ` Theodore Y. Ts'o
2018-09-26 18:10 ` Alan Cox
2018-09-26 21:49 ` Theodore Y. Ts'o
2018-09-27 22:48 ` Alan Cox
2018-09-27 7:18 ` Rogier Wolff
2018-09-27 12:43 ` Jeff Layton
2018-09-27 14:27 ` Theodore Y. Ts'o
2018-09-25 17:35 ` Adam Borowski
2018-09-25 22:46 ` Theodore Y. Ts'o
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