[PATCH 22/60] staging: lustre: fid: fix race in fid allocation

Dan Carpenter dan.carpenter at oracle.com
Tue Jan 31 08:55:42 UTC 2017


On Sat, Jan 28, 2017 at 07:04:50PM -0500, James Simmons wrote:
> -		if (!fid_is_zero(&seq->lcs_fid) &&
> -		    fid_oid(&seq->lcs_fid) < seq->lcs_width) {
> +		if (unlikely(!fid_is_zero(&seq->lcs_fid) &&
> +			     fid_oid(&seq->lcs_fid) < seq->lcs_width)) {

What does adding an unlikely have to do with the race condition?  Also
only add likely/unlikely when it makes a difference to benchmarks.
Otherwise leave it out.

>  			/* Just bump last allocated fid and return to caller. */
> -			seq->lcs_fid.f_oid += 1;
> +			seq->lcs_fid.f_oid++;

Ok...  I'm pretty sure the compiler can figure this out on its own.
Stop mixing white space changes into your bug fixes.  It just makes
reviewing more complicated.

>  			rc = 0;
>  			break;
>  		}
>  

regards,
dan carpenter


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