Re: [Xen-devel] [PATCH 2/2] scripts: Use stat to check lock claim

[Wei Liu <wl@xxxxxxx>]

On Thu, Mar 12, 2020 at 10:54:17AM -0400, Jason Andryuk wrote:
> Replace the perl locking check with stat(1).  Stat is able to fstat
> stdin (file descriptor 0) when passed '-' as an argument.  This is now
> used to check $_lockfd.  stat(1) support for '-' was introduced to
> coreutils in 2009.
> 
> After A releases its lock, script B will return from flock and execute
> stat.  Since the lockfile has been removed by A, stat prints an error to
> stderr and exits non-zero.  Redirect stderr to /dev/null to avoid
> filling /var/log/xen/xen-hotplug.log with "No such file or directory"
> messages.
> 
> Placing the stat call inside the "if" condition ensures we only check
> the stat output when the command completed successfully.
> 
> This change removes the only runtime dependency of the xen toolstack on
> perl.
> 
> Suggested-by: Ian Jackson <ian.jackson@xxxxxxxxxx>
> Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>

Ian, ping?

I already applied patch 1. This patch looks to be good as well.

Wei.