On Thu, 11 Jul 2013 10:49:18 -0400 Jeff Layton <jlayton@xxxxxxxxxx> wrote: > On Tue, 9 Jul 2013 19:16:45 +0300 > Nadav Shemer <nadav@xxxxxxxxxx> wrote: > > > Move ATTR_OPEN handling from nfs4_proc_setattr into nfs4_do_setattr > > > > Signed-off-by: Nadav Shemer <nadav@xxxxxxxxxx> > > --- > > 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. > Actually, disregard that comment. I was confused as to which function calls which here... Still, I think we'd do better to keep this logic consolidated in nfs4_proc_setattr instead of spreading it around. I'm a little concerned that this may change the behavior in the open codepath, which also calls nfs4_do_setattr. More 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; > It looks like we're just clearing ATTR_OPEN here in order to make the check that follows that happy. Would it make more sense to instead leave ATTR_OPEN set in this place and fix that check to ignore ATTR_OPEN? -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
