Re: [PATCH] super-intel: ensure suspended region is removed when reshape completes.

[Jes Sorensen <Jes.Sorensen@redhat.com>]

NeilBrown <neilb@suse.com> writes:
> A recent commit removed a call to abort_reshape() when IMSM reshape
> completed.  An unanticipated result of this is that the suspended
> region is not cleared as it should be.
> So after a reshape, a region of the array will cause all IO to block.
>
> Re-instate the required updates to suspend_{lo,hi} coped from
> abort_reshape().
>
> This is caught (sometimes) by the test suite.
>
> Also fix a couple of typos found while exploring the code.
>
> Reported-by: Ken Moffat <zarniwhoop@ntlworld.com>
> Cc: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
> Fixes: 2139b03c2080 ("imsm: don't call abort_reshape() in imsm_manage_reshape()")
> Signed-off-by: NeilBrown <neilb@suse.com>
> ---
>  super-intel.c | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/super-intel.c b/super-intel.c
> index 90b7b6dee5d0..80b48d0fdd47 100644
> --- a/super-intel.c
> +++ b/super-intel.c
> @@ -10465,7 +10465,7 @@ int check_degradation_change(struct mdinfo *info,
>   * Function:	imsm_manage_reshape
>   * Description:	Function finds array under reshape and it manages reshape
>   *		process. It creates stripes backups (if required) and sets
> - *		checheckpoits.
> + *		checkpoints.
>   * Parameters:
>   *	afd		: Backup handle (nattive) - not used
>   *	sra		: general array info
> @@ -10595,7 +10595,7 @@ static int imsm_manage_reshape(
>  
>  		start = current_position * 512;
>  
> -		/* allign reading start to old geometry */
> +		/* align reading start to old geometry */
>  		start_buf_shift = start % old_data_stripe_length;
>  		start_src = start - start_buf_shift;
>  
> @@ -10700,6 +10700,9 @@ static int imsm_manage_reshape(
>  	ret_val = 1;
>  abort:
>  	free(buf);
> +	sysfs_set_num(sra, NULL, "suspend_lo", 0x7FFFFFFFFFFFFFFFULL);
> +	sysfs_set_num(sra, NULL, "suspend_hi", 0);
> +	sysfs_set_num(sra, NULL, "suspend_lo", 0);
>  
>  	return ret_val;
>  }

This does indeed match the behavior of abort_reshape(), however looking
through git history, I cannot find any explanation as to why the code
sets suspend_lo twice.

Any chance you can enlighten me why this is necessary?

Thanks,
Jes