Re: [PATCH] nfsd: Fix error cleanup path in nfsd_rename()

[Chuck Lever <chuck.lever@oracle.com>]

On Tue, Mar 19, 2024 at 02:53:54PM +0100, Jan Kara wrote:
> On Mon 18-03-24 16:12:17, Chuck Lever wrote:
> > On Mon, Mar 18, 2024 at 05:32:09PM +0100, Jan Kara wrote:
> > > Commit a8b0026847b8 ("rename(): avoid a deadlock in the case of parents
> > > having no common ancestor") added an error bail out path. However this
> > > path does not drop the remount protection that has been acquired. Fix
> > > the cleanup path to properly drop the remount protection.
> > > 
> > > Fixes: a8b0026847b8 ("rename(): avoid a deadlock in the case of parents having no common ancestor")
> > > Signed-off-by: Jan Kara <jack@suse.cz>
> > 
> > Al, Jan, let me know if you'd like me to take this through the
> > nfsd tree for v6.9-rc. If not:
> > 
> > Acked-by: Chuck Lever <chuck.lever@oracle.com>
> 
> Yeah, I guess taking this through NFS tree is the best.

I've pushed this to my nfsd-fixes branch, and will begin testing.


> 								Honza
> 
> > 
> > 
> > > ---
> > >  fs/nfsd/vfs.c | 3 ++-
> > >  1 file changed, 2 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
> > > index 6a9464262fae..2e41eb4c3cec 100644
> > > --- a/fs/nfsd/vfs.c
> > > +++ b/fs/nfsd/vfs.c
> > > @@ -1852,7 +1852,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> > >  	trap = lock_rename(tdentry, fdentry);
> > >  	if (IS_ERR(trap)) {
> > >  		err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
> > > -		goto out;
> > > +		goto out_want_write;
> > >  	}
> > >  	err = fh_fill_pre_attrs(ffhp);
> > >  	if (err != nfs_ok)
> > > @@ -1922,6 +1922,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
> > >  	}
> > >  out_unlock:
> > >  	unlock_rename(tdentry, fdentry);
> > > +out_want_write:
> > >  	fh_drop_write(ffhp);
> > >  
> > >  	/*
> > > -- 
> > > 2.35.3
> > > 
> > 
> > -- 
> > Chuck Lever
> > 
> -- 
> Jan Kara <jack@suse.com>
> SUSE Labs, CR

-- 
Chuck Lever