[Cluster-devel] [GFS2 PATCH] GFS2: Allow flocks to use normal glock dq rather than dq_wait

[Steven Whitehouse <swhiteho@redhat.com>]

Hi,

Both patches are now in the -nmw tree. Thanks,

Steve.

On Thu, 2014-06-26 at 10:46 -0400, Bob Peterson wrote:
> Hi,
> 
> This patch allows flock glocks to use a non-blocking dequeue rather
> than dq_wait. It also reverts the previous patch I had posted regarding
> dq_wait. The reverted patch isn't necessarily a bad idea, but I decided
> this might avoid unforeseen side effects, and was therefore safer.
> 
> Regards,
> 
> Bob Peterson
> Red Hat File Systems
> 
> Signed-off-by: Bob Peterson <rpeterso@redhat.com> 
> ---
> diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
> index 0740a57..26b3f95 100644
> --- a/fs/gfs2/file.c
> +++ b/fs/gfs2/file.c
> @@ -991,7 +991,7 @@ static int do_flock(struct file *file, int cmd, struct file_lock *fl)
>  			goto out;
>  		flock_lock_file_wait(file,
>  				     &(struct file_lock){.fl_type = F_UNLCK});
> -		gfs2_glock_dq_wait(fl_gh);
> +		gfs2_glock_dq(fl_gh);
>  		gfs2_holder_reinit(state, flags, fl_gh);
>  	} else {
>  		error = gfs2_glock_get(GFS2_SB(&ip->i_inode), ip->i_no_addr,
> diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
> index b703dcc..ee4e04f 100644
> --- a/fs/gfs2/glock.c
> +++ b/fs/gfs2/glock.c
> @@ -1128,9 +1128,7 @@ void gfs2_glock_dq_wait(struct gfs2_holder *gh)
>  	struct gfs2_glock *gl = gh->gh_gl;
>  	gfs2_glock_dq(gh);
>  	might_sleep();
> -	if (!find_first_holder(gl))
> -		wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait,
> -			    TASK_UNINTERRUPTIBLE);
> +	wait_on_bit(&gl->gl_flags, GLF_DEMOTE, gfs2_glock_demote_wait, TASK_UNINTERRUPTIBLE);
>  }
>  
>  /**
>