Re: [PATCH 4/4] WORKAROUND: mdadm hangs during reshape

[Neil Brown <neilb@suse.de>]

On Thu, 20 Jan 2011 11:57:46 +0100
Adam Kwolek <adam.kwolek@intel.com> wrote:

> During reshape when reshape is finished in md, progress_reshape()
> hangs on select(). Timeout is introduced to allow for reshape
> conditions check.
> 
> You point in the email that you do not like this solution.
> It is put in to series as reminder.

Thanks for the reminder.  
I figured out what is really happening and wrote a better work-around.
You can find it in the git history - fully commented.

Thanks,
NeilBrown

> 
> Signed-off-by: Adam Kwolek <adam.kwolek@intel.com>
> ---
> 
>  Grow.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/Grow.c b/Grow.c
> index 717d087..c9f4b9c 100644
> --- a/Grow.c
> +++ b/Grow.c
> @@ -2394,6 +2394,7 @@ int progress_reshape(struct mdinfo *info,
> struct reshape *reshape,
>  		 * waiting forever on a dead array
>  		 */
>  		char action[20];
> +		struct timeval timeout;
>  		fd_set rfds;
>  		if (sysfs_get_str(info, NULL, "sync_action",
>  				  action, 20) <= 0 ||
> @@ -2401,7 +2402,9 @@ int progress_reshape(struct mdinfo *info,
> struct reshape *reshape, break;
>  		FD_ZERO(&rfds);
>  		FD_SET(fd, &rfds);
> -		select(fd+1, NULL, NULL, &rfds, NULL);
> +		timeout.tv_sec = 1;
> +		timeout.tv_usec = 0;
> +		select(fd+1, NULL, NULL, &rfds, &timeout);
>  		if (sysfs_fd_get_ll(fd, &completed) < 0) {
>  			close(fd);
>  			goto check_progress;