Re: cifs unable to access shares with read restricted at root level (bso#8950)

["Aurélien Aptel" <aaptel-IBi9RG/b67k@public.gmane.org>]

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Oops, I forgot to CC my last email to the mailing list; re-sending now.

On Tue, 27 Oct 2015 19:43:46 -0500 Shirish Pargaonkar
<shirishpargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> On Tue, Oct 27, 2015 at 4:59 AM, Aurélien Aptel <aaptel-IBi9RG/b67k@public.gmane.org>
> wrote:  
> > Hi Shirish,
> >
> > On Mon, 26 Oct 2015 22:04:28 -0500 Shirish Pargaonkar
> > <shirishpargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:  
> >> They are stored in a linked list of struct cifs_rdelem off of
> >> superblock where each element of this linked list points to a
> >> disconnected dentry.  
> >
> > This list is only used use when we mount with noserverino. It
> > doesn't work in both case anyway.  
> 
> No, that is not the case. I have tested this against a Windows 2012
> server and did not mount the shares with noserverino option.
> Since we can query info off of disconnected entires, we fill the
> inodes which get filled with correct inode info as dentires get
> spliced.  

The only function that adds elements to the rdlist is this one, and it
only does so with noserverino. I believe d_obtain_alias() doesn't store
the full path on the share associated with the disconnected entry it creates.
The full path is therefore lost and build_path_from_dentry() fails.

static struct dentry *
create_root_dis_dentry(struct super_block *sb, struct inode *rinode,
			char *fpath)
{
	int rc;
	unsigned int xid;
	struct dentry *dentry = NULL;
	struct cifs_rdelem *rdelem = NULL;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);

	printk("create_root_dis_dentry %s, rinode %p\n", fpath, rinode);
	
	xid = get_xid();
	if (tcon->unix_ext)
		rc = cifs_get_inode_info_unix(&rinode, fpath, sb, xid);
	else
		rc = cifs_get_inode_info(&rinode, fpath, NULL, sb, xid, NULL);
	free_xid(xid);
	
	if ((rc == 0) && (rinode != NULL)) {
		dentry = d_obtain_alias(rinode);
		if (IS_ERR(dentry)) {
			iput(rinode);
			goto rdelem_ret;
		}

		if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {

			rdelem =
				cifs_alloc_rdelem(fpath, dentry, rinode);
			if (IS_ERR(rdelem))
				goto rdelem_ret;
			spin_lock(&cifs_sb->rtdislock);
			list_add(&rdelem->rdlist, &cifs_sb->rtdislist);
			spin_unlock(&cifs_sb->rtdislock);
		}
		return dentry;
	}

rdelem_ret:
	return ERR_PTR(-EACCES);
}

 
> Sorry, missed looking at the link before. yes, the same setup.
> I could never get right seutp for Samba server.  

I must be missing something because I cannot make your patch work.
We're using the exact same setup.

-- 
Aurélien Aptel / SUSE Labs Samba Team
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SUSE Linux GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG
Nürnberg)

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