Re: [PATCH] nfs: drop acl cache in __nfs3_proc_setacls

[Trond Myklebust <trondmy@hammerspace.com>]

Hi,

On Fri, 2019-02-22 at 15:35 +0800, yangerkun wrote:
> Ping?
> 
> yangerkun wrote on 2019/2/20 15:29:
> > Since server may call posix_acl_update_mode which can lead acl been
> > NULL. So,just drop acl cache after rpc_call_sync, and if anyone
> > want to
> > use acl, they can get the correct acl by send a msg to server
> > themselves.
> > This can fix xfstests generic/099 over nfsv3.
> > 
> > Signed-off-by: yangerkun <yangerkun@huawei.com>
> > ---
> >   fs/nfs/nfs3acl.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/fs/nfs/nfs3acl.c b/fs/nfs/nfs3acl.c
> > index 9fce185..6c07ebc 100644
> > --- a/fs/nfs/nfs3acl.c
> > +++ b/fs/nfs/nfs3acl.c
> > @@ -222,8 +222,8 @@ static int __nfs3_proc_setacls(struct inode
> > *inode, struct posix_acl *acl,
> >   	switch (status) {
> >   		case 0:
> >   			status = nfs_refresh_inode(inode, fattr);
> > -			set_cached_acl(inode, ACL_TYPE_ACCESS, acl);
> > -			set_cached_acl(inode, ACL_TYPE_DEFAULT, dfacl);
> > +			/* Sever may call posix_acl_update_mode */
> > +			forget_all_cached_acls(inode);
> >   			break;
> >   		case -EPFNOSUPPORT:
> >   		case -EPROTONOSUPPORT:
> > 

I've applied the following patch 
http://git.linux-nfs.org/?p=trondmy/linux-nfs.git;a=commitdiff;h=ded52fbe7020a5696b0b0a0fdbf234e37bf16f94
in order to fix this issue.

The reason why I prefer that fix is that we're already calling
nfs_zap_acl_cache(inode) immediately before this switch statement, so
the call to 'forget_all_cached_acls()' appears redundant.

Thanks!
  Trond 

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com