Re: iov_iter_pipe warning.

From	Al Viro <viro@ZenIV.linux.org.uk>
Newsgroups	linux.kernel
Subject	Re: iov_iter_pipe warning.
Date	2017-09-10 23:20 +0200
Message-ID	<uohO3-1dX-33@gated-at.bofh.it> (permalink)
References	(5 earlier) <umSeZ-dZ-5@gated-at.bofh.it> <unfXX-8dp-3@gated-at.bofh.it> <unYV3-4ZZ-5@gated-at.bofh.it> <uo0Dv-5VJ-3@gated-at.bofh.it> <uohO2-1dX-19@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon, Sep 11, 2017 at 07:11:10AM +1000, Dave Chinner wrote:
> On Sun, Sep 10, 2017 at 03:57:21AM +0100, Al Viro wrote:
> > On Sat, Sep 09, 2017 at 09:07:56PM -0400, Dave Jones wrote:
> > 
> > > With this in place, I'm still seeing -EBUSY from invalidate_inode_pages2_range
> > > which doesn't end well...
> > 
> > Different issue, and I'm not sure why that WARN_ON() is there in the
> > first place.  Note that in a similar situation generic_file_direct_write()
> > simply buggers off and lets the caller do buffered write...
> 
> XFS does not fall back to buffered IO when direct IO fails.  A
> direct IO failure is indicative of a problem that needs to be fixed,
> not use a "let's hope we can hide this" fallback path. Especially in
> this case - EBUSY usually comes from the app is doing something we
> /know/ is dangerous and it's occurrence to completely timing
> dependent - if the timing is slightly different, we miss detection
> and that can lead to silent data corruption.

In this case app is a fuzzer, which is bloody well supposed to poke
into all kinds of odd usage patterns, though...

Thread

Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-08-28 22:40 +0200
  Re: iov_iter_pipe warning. "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-08-29 06:30 +0200
    Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-08-30 19:10 +0200
      Re: iov_iter_pipe warning. "Darrick J. Wong" <darrick.wong@oracle.com> - 2017-08-30 19:20 +0200
        Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-08-30 19:20 +0200
    Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-09-06 22:10 +0200
      Re: iov_iter_pipe warning. Dave Chinner <david@fromorbit.com> - 2017-09-07 01:50 +0200
        Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-09-07 05:50 +0200
          Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-07 06:40 +0200
        Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-08 03:10 +0200
          Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-09-10 03:10 +0200
            Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-10 05:00 +0200
              Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-09-10 18:10 +0200
                Re: iov_iter_pipe warning. Dave Jones <davej@codemonkey.org.uk> - 2017-09-10 22:10 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-10 22:40 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-10 22:10 +0200
              Re: iov_iter_pipe warning. Dave Chinner <david@fromorbit.com> - 2017-09-10 23:20 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-10 23:20 +0200
                Re: iov_iter_pipe warning. Dave Chinner <david@fromorbit.com> - 2017-09-11 00:10 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-11 01:10 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-11 01:20 +0200
                Re: iov_iter_pipe warning. Dave Chinner <david@fromorbit.com> - 2017-09-11 02:40 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-11 05:40 +0200
                Re: iov_iter_pipe warning. Dave Chinner <david@fromorbit.com> - 2017-09-11 08:50 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-11 22:10 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-11 22:20 +0200
                Re: iov_iter_pipe warning. Dave Chinner <david@fromorbit.com> - 2017-09-12 08:10 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-12 13:20 +0200
                Re: iov_iter_pipe warning. Christoph Hellwig <hch@infradead.org> - 2017-09-11 14:10 +0200
                Re: iov_iter_pipe warning. Al Viro <viro@ZenIV.linux.org.uk> - 2017-09-11 15:00 +0200

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