Re: [PATCH] ceph: don't leak snap_rwsem in handle_cap_grant

["Luís Henriques" <lhenriques@suse.de>]

Jeff Layton <jlayton@kernel.org> writes:

> When handle_cap_grant is called on an IMPORT op, then the snap_rwsem is
> held and the function is expected to release it before returning. It
> currently fails to do that in all cases which could lead to a deadlock.
>
> URL: https://tracker.ceph.com/issues/55857

This looks good.  Maybe it could have here a 'Fixes: e8a4d26771547'.
Otherwise:

Reviewed-by: Luís Henriques <lhenriques@suse.de>

Cheers,
-- 
Luís


> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  fs/ceph/caps.c | 27 +++++++++++++--------------
>  1 file changed, 13 insertions(+), 14 deletions(-)
>
> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
> index 258093e9074d..0a48bf829671 100644
> --- a/fs/ceph/caps.c
> +++ b/fs/ceph/caps.c
> @@ -3579,24 +3579,23 @@ static void handle_cap_grant(struct inode *inode,
>  			fill_inline = true;
>  	}
>  
> -	if (ci->i_auth_cap == cap &&
> -	    le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT) {
> -		if (newcaps & ~extra_info->issued)
> -			wake = true;
> +	if (le32_to_cpu(grant->op) == CEPH_CAP_OP_IMPORT) {
> +		if (ci->i_auth_cap == cap) {
> +			if (newcaps & ~extra_info->issued)
> +				wake = true;
> +
> +			if (ci->i_requested_max_size > max_size ||
> +			    !(le32_to_cpu(grant->wanted) & CEPH_CAP_ANY_FILE_WR)) {
> +				/* re-request max_size if necessary */
> +				ci->i_requested_max_size = 0;
> +				wake = true;
> +			}
>  
> -		if (ci->i_requested_max_size > max_size ||
> -		    !(le32_to_cpu(grant->wanted) & CEPH_CAP_ANY_FILE_WR)) {
> -			/* re-request max_size if necessary */
> -			ci->i_requested_max_size = 0;
> -			wake = true;
> +			ceph_kick_flushing_inode_caps(session, ci);
>  		}
> -
> -		ceph_kick_flushing_inode_caps(session, ci);
> -		spin_unlock(&ci->i_ceph_lock);
>  		up_read(&session->s_mdsc->snap_rwsem);
> -	} else {
> -		spin_unlock(&ci->i_ceph_lock);
>  	}
> +	spin_unlock(&ci->i_ceph_lock);
>  
>  	if (fill_inline)
>  		ceph_fill_inline_data(inode, NULL, extra_info->inline_data,
> -- 
>
> 2.36.1
>