Re: [PATCH] lockd: Show pid of lockd for remote locks

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Nov 02, 2018 at 02:45:16PM -0400, J. Bruce Fields wrote:
> On Thu, Nov 01, 2018 at 01:39:49PM -0400, Benjamin Coddington wrote:
> > Commit 9d5b86ac13c5 ("fs/locks: Remove fl_nspid and use fs-specific l_pid
> > for remote locks") specified that the l_pid returned for F_GETLK on a local
> > file that has a remote lock should be the pid of the lock manager process.
> > That commit, while updating other filesystems, failed to update lockd, such
> > that locks created by lockd had their fl_pid set to that of the remote
> > process holding the lock.  Fix that here to be the pid of lockd.
> > 
> > Also, fix the client case so that the returned lock pid is negative, which
> > indicates a remote lock on a remote file.
> 
> ACK.
> 
> Uh, I guess I'll take this if nobody else speaks up.

Applied for 4.21.--b.

> 
> --b.
> 
> > 
> > Fixes: 9d5b86ac13c5 ("fs/locks: Remove fl_nspid and use fs-specific...")
> > Cc: stable@vger.kernel.org
> > 
> > Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
> > ---
> >  fs/lockd/clntproc.c | 2 +-
> >  fs/lockd/xdr.c      | 4 ++--
> >  fs/lockd/xdr4.c     | 4 ++--
> >  3 files changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
> > index d20b92f271c2..0a67dd4250e9 100644
> > --- a/fs/lockd/clntproc.c
> > +++ b/fs/lockd/clntproc.c
> > @@ -442,7 +442,7 @@ nlmclnt_test(struct nlm_rqst *req, struct file_lock *fl)
> >  			fl->fl_start = req->a_res.lock.fl.fl_start;
> >  			fl->fl_end = req->a_res.lock.fl.fl_end;
> >  			fl->fl_type = req->a_res.lock.fl.fl_type;
> > -			fl->fl_pid = 0;
> > +			fl->fl_pid = -req->a_res.lock.fl.fl_pid;
> >  			break;
> >  		default:
> >  			status = nlm_stat_to_errno(req->a_res.status);
> > diff --git a/fs/lockd/xdr.c b/fs/lockd/xdr.c
> > index 7147e4aebecc..9846f7e95282 100644
> > --- a/fs/lockd/xdr.c
> > +++ b/fs/lockd/xdr.c
> > @@ -127,7 +127,7 @@ nlm_decode_lock(__be32 *p, struct nlm_lock *lock)
> >  
> >  	locks_init_lock(fl);
> >  	fl->fl_owner = current->files;
> > -	fl->fl_pid   = (pid_t)lock->svid;
> > +	fl->fl_pid   = current->tgid;
> >  	fl->fl_flags = FL_POSIX;
> >  	fl->fl_type  = F_RDLCK;		/* as good as anything else */
> >  	start = ntohl(*p++);
> > @@ -269,7 +269,7 @@ nlmsvc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
> >  	memset(lock, 0, sizeof(*lock));
> >  	locks_init_lock(&lock->fl);
> >  	lock->svid = ~(u32) 0;
> > -	lock->fl.fl_pid = (pid_t)lock->svid;
> > +	lock->fl.fl_pid = current->tgid;
> >  
> >  	if (!(p = nlm_decode_cookie(p, &argp->cookie))
> >  	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
> > diff --git a/fs/lockd/xdr4.c b/fs/lockd/xdr4.c
> > index 7ed9edf9aed4..70154f376695 100644
> > --- a/fs/lockd/xdr4.c
> > +++ b/fs/lockd/xdr4.c
> > @@ -119,7 +119,7 @@ nlm4_decode_lock(__be32 *p, struct nlm_lock *lock)
> >  
> >  	locks_init_lock(fl);
> >  	fl->fl_owner = current->files;
> > -	fl->fl_pid   = (pid_t)lock->svid;
> > +	fl->fl_pid   = current->tgid;
> >  	fl->fl_flags = FL_POSIX;
> >  	fl->fl_type  = F_RDLCK;		/* as good as anything else */
> >  	p = xdr_decode_hyper(p, &start);
> > @@ -266,7 +266,7 @@ nlm4svc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p)
> >  	memset(lock, 0, sizeof(*lock));
> >  	locks_init_lock(&lock->fl);
> >  	lock->svid = ~(u32) 0;
> > -	lock->fl.fl_pid = (pid_t)lock->svid;
> > +	lock->fl.fl_pid = current->tgid;
> >  
> >  	if (!(p = nlm4_decode_cookie(p, &argp->cookie))
> >  	 || !(p = xdr_decode_string_inplace(p, &lock->caller,
> > -- 
> > 2.14.3