Return-Path: linux-nfs-owner@vger.kernel.org Received: from mx1.redhat.com ([209.132.183.28]:40264 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932531Ab3GKOtX (ORCPT ); Thu, 11 Jul 2013 10:49:23 -0400 Date: Thu, 11 Jul 2013 10:49:18 -0400 From: Jeff Layton To: Nadav Shemer Cc: Trond.Myklebust@netapp.com, linux-nfs@vger.kernel.org Subject: Re: [PATCH] NFSv4: fix open(O_RDONLY|O_TRUNC) returning EBADF Message-ID: <20130711104918.589cefe7@tlielax.poochiereds.net> In-Reply-To: <1373386605-18684-1-git-send-email-nadav@tonian.com> References: <1373386605-18684-1-git-send-email-nadav@tonian.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Tue, 9 Jul 2013 19:16:45 +0300 Nadav Shemer wrote: > Move ATTR_OPEN handling from nfs4_proc_setattr into nfs4_do_setattr > > Signed-off-by: Nadav Shemer > --- > Hello. > > I've come across an oddity while testing filesystem coverage > My test creates a non-empty file without write permissions and tries to open it with O_RDONLY|O_TRUNC > It expects EACCES (and gets that for local filesystems and NFSv3) but gets EBADF on NFSv4 (and v4.1) > > I found some history on this: In a previous kernel it would just hang due to mishandling the NFS4ERR_OPENMODE exception > http://www.spinics.net/lists/linux-nfs/msg28881.html > > A fix for this was introduced (it specifically tests for NFS4ERR_OPENMODE and returns EACCES for the open() case, EBADF otherwise) > http://www.spinics.net/linux/fedora/fedora-kernel/msg03736.html > but another patch was also introduced in the same set which seems to break it (it optimizes away the time modification and removes ATTR_OPEN in nfs4_proc_setattr) > http://www.spinics.net/linux/fedora/fedora-kernel/msg03732.html > > By moving the 'Deal with open(O_TRUNC)' bit inside (into nfs4_do_setattr), I got it working again (with no other functional change, as far as I can see) > > fs/nfs/nfs4proc.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c > index 8fbc100..17b9f32 100644 > --- a/fs/nfs/nfs4proc.c > +++ b/fs/nfs/nfs4proc.c > @@ -2180,6 +2180,10 @@ static int nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred, > .inode = inode, > }; > int err; > + int is_o_trunc = sattr->ia_valid & ATTR_OPEN; > + /* Deal with open(O_TRUNC) */ > + if (sattr->ia_valid & ATTR_OPEN) > + sattr->ia_valid &= ~(ATTR_MTIME|ATTR_CTIME|ATTR_OPEN); I'm not sure you really need to move the above if statement into this function, do you? I think it'd be best to leave that where it is and just add the is_o_trunc variable the special handling for it below. > do { > err = _nfs4_do_setattr(inode, cred, fattr, sattr, state); > switch (err) { > @@ -2193,7 +2197,7 @@ static int nfs4_do_setattr(struct inode *inode, struct rpc_cred *cred, > } > if (state && !(state->state & FMODE_WRITE)) { > err = -EBADF; > - if (sattr->ia_valid & ATTR_OPEN) > + if (is_o_trunc) > err = -EACCES; > goto out; > } > @@ -2774,10 +2778,6 @@ nfs4_proc_setattr(struct dentry *dentry, struct nfs_fattr *fattr, > > nfs_fattr_init(fattr); > > - /* Deal with open(O_TRUNC) */ > - if (sattr->ia_valid & ATTR_OPEN) > - sattr->ia_valid &= ~(ATTR_MTIME|ATTR_CTIME|ATTR_OPEN); > - > /* Optimization: if the end result is no change, don't RPC */ > if ((sattr->ia_valid & ~(ATTR_FILE)) == 0) > return 0; Otherwise, it looks reasonable... Acked-by: Jeff Layton