lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Fri, 20 Jan 2012 15:01:57 +0100
From:	Jan Kara <jack@...e.cz>
To:	Tomer Margalit <tomermargalit@...il.com>
Cc:	linux-kernel@...r.kernel.org,
	Nezer Zaidenberg <nzaidenberg@....com>
Subject: Re: Failing a bio right

  Hello,

On Thu 19-01-12 18:04:19, Tomer Margalit wrote:
> I have a make_request function that blocks writes (by using
> wait_event_interruptible on some event).
> I want the user to be able to stop the function if it takes too long
> (that's the reason for the interruptible version).
> So when the call is interrupted I call bio_endio with the EINTR error
> to signal the interruption.
> Usually this works fine, but after a lot of writes, the system says
> "lost page write due to I/O error on device".
  This is because end_buffer_write_sync() doesn't really distinguish
errors.  So when some error happens it complains about I/O error.

> At this point the process hangs.
  That is strange - you should probably collect stack trace of the failing
process (e.g. via 'echo w >/proc/sysrq-trigger'). That should tell us more.

> Is this the right way to do what I'm trying to do?
  I'm not sure how is it supposed to work. Writes happen usually in an
async manner (through page cache and flusher thread) or are you using
direct IO? Also if a write is interrupted at this point, you just lost the
content of the buffer (as it is marked clean and !uptodate). Users usually
don't like that.

								Honza
-- 
Jan Kara <jack@...e.cz>
SUSE Labs, CR
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists