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From:   David Howells <dhowells@redhat.com>
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To:     Jeff Layton <jlayton@kernel.org>
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        andres@anarazel.de, cmaiolino@redhat.com,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 0/4] vfs: track per-sb writeback errors and report them via fsinfo()
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Date:   Tue, 10 Jul 2018 15:23:29 +0100
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Jeff Layton <jlayton@kernel.org> wrote:

> v2: drop buffer.c patch to record wb errors when underlying blockdev
> flush fails. We may eventually want that, but at this point I don't have
> a clear way to test it to determine its efficacy.
> 
> At LSF/MM this year, the PostgreSQL developers mentioned that they'd
> like to have some mechanism to check whether there have been any
> writeback errors on a filesystem, without necessarily flushing any of
> the cached data first.
> 
> Given that we have a new fsinfo syscall being introduced, we may as well
> use it to report writeback errors on a per superblock basis. This allows
> us to provide the info that the PostgreSQL developers wanted, without
> needing to change an existing interface.
> 
> This seems to do the right thing when tested by hand, but I don't yet
> have an xfstest for it, since the syscall is still quite new. Once that
> goes in and we get fsinfo support in xfs_io, it should be rather
> trivial to roll a testcase for this.

Reviewed-by: David Howells <dhowells@redhat.com>