Re: [v4.14.y PATCH] errseq: Always report a writeback error once

[Greg KH <greg@kroah.com>]

On Sun, May 06, 2018 at 11:59:57AM -0400, Jeff Layton wrote:
> From: Matthew Wilcox <willy@infradead.org>
> 
> The errseq_t infrastructure assumes that errors which occurred before
> the file descriptor was opened are of no interest to the application.
> This turns out to be a regression for some applications, notably Postgres.
> 
> Before errseq_t, a writeback error would be reported exactly once (as
> long as the inode remained in memory), so Postgres could open a file,
> call fsync() and find out whether there had been a writeback error on
> that file from another process.
> 
> This patch changes the errseq infrastructure to report errors to all
> file descriptors which are opened after the error occurred, but before
> it was reported to any file descriptor.  This restores the user-visible
> behaviour.
> 
> [ jlayton: fix up conflicts in comments ]
> 
> Cc: stable@vger.kernel.org
> Fixes: 5660e13d2fd6 ("fs: new infrastructure for writeback error handling and reporting")
> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> Signed-off-by: Jeff Layton <jlayton@redhat.com>
> (cherry picked from commit b4678df184b314a2bd47d2329feca2c2534aa12b)
> ---
>  lib/errseq.c | 25 +++++++++++--------------
>  1 file changed, 11 insertions(+), 14 deletions(-)
> 
> This is a backport to the v4.14 stable series. The only merge conflict
> was due to an earlier patch by Willy to flesh out the comments. There
> were no code changes necessary.

Thanks for the backport, now queued up.

greg k-h