From: Dave Chinner <david@fromorbit.com>
To: Bill Kendall <wkendall@sgi.com>
Cc: xfs@oss.sgi.com
Subject: Re: [PATCH] xfsdump: allow system() to obtain exit status
Date: Thu, 12 Jan 2012 09:20:36 +1100 [thread overview]
Message-ID: <20120111222036.GK24410@dastard> (raw)
In-Reply-To: <1326316073-15033-1-git-send-email-wkendall@sgi.com>
On Wed, Jan 11, 2012 at 03:07:53PM -0600, Bill Kendall wrote:
> xfsdump explicitly ignores SIGCHLD in order to prevent librmt rsh
> processes from becoming zombies. However, doing so interferes with the
> ability for system() to determine a command's exit status.
>
> Setting up a handler for SIGCHLD will not work either, since xfsdump is
> now multi-threaded and the main thread (which handles signals) might
> handle a child exit before the thread running system() can.
>
> I also attempted to use waitpid() when tearing down a librmt session,
> but this has the potential to block indefinitely if there is a problem
> on the remote side. (And using WNOHANG tended to never catch the exit.)
>
> In the end, I settled on just not touching SIGCHLD at all. There may be
> a zombie rsh when librmt is used, but typically it will be alive until
> the end of the backup and in any case will be cleaned up when
> xfsdump/restore exits.
>
> Signed-off-by: Bill Kendall <wkendall@sgi.com>
Looks OK to me.
Reviewed-by: Dave Chinner <dchinner@redhat.com>
--
Dave Chinner
david@fromorbit.com
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prev parent reply other threads:[~2012-01-11 22:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-10 2:42 xfsdump 3.0.6, ERROR: xfs_quota failed with exit status: -1 Tommy Wu
2012-01-11 14:53 ` Bill Kendall
2012-01-11 21:07 ` [PATCH] xfsdump: allow system() to obtain exit status Bill Kendall
2012-01-11 22:20 ` Dave Chinner [this message]
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