25  * Probe to see if a cell may exist.  This prevents positive dentries from
30 	struct afs_cell *cell;  in afs_probe_cell_name()  local
31 	const char *name = dentry->d_name.name;  in afs_probe_cell_name()
32 	size_t len = dentry->d_name.len;  in afs_probe_cell_name()
37 		if (len == 1)  in afs_probe_cell_name()
38 			return -EINVAL;  in afs_probe_cell_name()
40 		len--;  in afs_probe_cell_name()
43 	cell = afs_lookup_cell_rcu(afs_d2net(dentry), name, len);  in afs_probe_cell_name()
44 	if (!IS_ERR(cell)) {  in afs_probe_cell_name()
45 		afs_put_cell(afs_d2net(dentry), cell);  in afs_probe_cell_name()
50 	if (ret == -ENODATA)  in afs_probe_cell_name()
51 		ret = -EDESTADDRREQ;  in afs_probe_cell_name()
63 	int ret = -ENOENT;  in afs_try_auto_mntpt()
66 	       dentry, dentry, vnode->fid.vid, vnode->fid.vnode);  in afs_try_auto_mntpt()
68 	if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))  in afs_try_auto_mntpt()
75 	inode = afs_iget_pseudo_dir(dir->i_sb, false);  in afs_try_auto_mntpt()
86 	return ret == -ENOENT ? NULL : ERR_PTR(ret);  in afs_try_auto_mntpt()
90  * Look up @cell in a dynroot directory.  This is a substitution for the
91  * local cell name for the net namespace.
95 	struct afs_cell *cell;  in afs_lookup_atcell()  local
102 	if (!net->ws_cell)  in afs_lookup_atcell()
103 		return ERR_PTR(-ENOENT);  in afs_lookup_atcell()
105 	ret = ERR_PTR(-ENOMEM);  in afs_lookup_atcell()
106 	name = kmalloc(AFS_MAXCELLNAME + 1, GFP_KERNEL);  in afs_lookup_atcell()
112 		read_seqbegin_or_lock(&net->cells_lock, &seq);  in afs_lookup_atcell()
113 		cell = rcu_dereference_raw(net->ws_cell);  in afs_lookup_atcell()
114 		if (cell) {  in afs_lookup_atcell()
115 			len = cell->name_len;  in afs_lookup_atcell()
116 			memcpy(name, cell->name, len + 1);  in afs_lookup_atcell()
118 	} while (need_seqretry(&net->cells_lock, seq));  in afs_lookup_atcell()
119 	done_seqretry(&net->cells_lock, seq);  in afs_lookup_atcell()
122 	ret = ERR_PTR(-ENOENT);  in afs_lookup_atcell()
123 	if (!cell)  in afs_lookup_atcell()
126 	ret = lookup_one_len(name, dentry->d_parent, len);  in afs_lookup_atcell()
128 	/* We don't want to d_add() the @cell dentry here as we don't want to  in afs_lookup_atcell()
129 	 * the cached dentry to hide changes to the local cell name.  in afs_lookup_atcell()
149 		return ERR_PTR(-EOPNOTSUPP);  in afs_dynroot_lookup()
151 	if (dentry->d_name.len >= AFSNAMEMAX) {  in afs_dynroot_lookup()
152 		_leave(" = -ENAMETOOLONG");  in afs_dynroot_lookup()
153 		return ERR_PTR(-ENAMETOOLONG);  in afs_dynroot_lookup()
156 	if (dentry->d_name.len == 5 &&  in afs_dynroot_lookup()
157 	    memcmp(dentry->d_name.name, "@cell", 5) == 0)  in afs_dynroot_lookup()
172 	return 1;  in afs_dynroot_d_revalidate()
178  * - called from dput() when d_count is going to 0.
179  * - return 1 to request dentry be unhashed, 0 otherwise
194  * Create a manually added cell mount directory.
195  * - The caller must hold net->proc_cells_lock
197 int afs_dynroot_mkdir(struct afs_net *net, struct afs_cell *cell)  in afs_dynroot_mkdir()  argument
199 	struct super_block *sb = net->dynroot_sb;  in afs_dynroot_mkdir()
203 	if (!sb || atomic_read(&sb->s_active) == 0)  in afs_dynroot_mkdir()
206 	/* Let the ->lookup op do the creation */  in afs_dynroot_mkdir()
207 	root = sb->s_root;  in afs_dynroot_mkdir()
208 	inode_lock(root->d_inode);  in afs_dynroot_mkdir()
209 	subdir = lookup_one_len(cell->name, root, cell->name_len);  in afs_dynroot_mkdir()
216 	subdir->d_fsdata = (void *)1UL;  in afs_dynroot_mkdir()
219 	inode_unlock(root->d_inode);  in afs_dynroot_mkdir()
224  * Remove a manually added cell mount directory.
225  * - The caller must hold net->proc_cells_lock
227 void afs_dynroot_rmdir(struct afs_net *net, struct afs_cell *cell)  in afs_dynroot_rmdir()  argument
229 	struct super_block *sb = net->dynroot_sb;  in afs_dynroot_rmdir()
232 	if (!sb || atomic_read(&sb->s_active) == 0)  in afs_dynroot_rmdir()
235 	root = sb->s_root;  in afs_dynroot_rmdir()
236 	inode_lock(root->d_inode);  in afs_dynroot_rmdir()
238 	/* Don't want to trigger a lookup call, which will re-add the cell */  in afs_dynroot_rmdir()
239 	subdir = try_lookup_one_len(cell->name, root, cell->name_len);  in afs_dynroot_rmdir()
247 	if (subdir->d_fsdata) {  in afs_dynroot_rmdir()
249 		subdir->d_fsdata = NULL;  in afs_dynroot_rmdir()
254 	inode_unlock(root->d_inode);  in afs_dynroot_rmdir()
259  * Populate a newly created dynamic root with cell names.
263 	struct afs_cell *cell;  in afs_dynroot_populate()  local
267 	if (mutex_lock_interruptible(&net->proc_cells_lock) < 0)  in afs_dynroot_populate()
268 		return -ERESTARTSYS;  in afs_dynroot_populate()
270 	net->dynroot_sb = sb;  in afs_dynroot_populate()
271 	hlist_for_each_entry(cell, &net->proc_cells, proc_link) {  in afs_dynroot_populate()
272 		ret = afs_dynroot_mkdir(net, cell);  in afs_dynroot_populate()
279 	mutex_unlock(&net->proc_cells_lock);  in afs_dynroot_populate()
283 	net->dynroot_sb = NULL;  in afs_dynroot_populate()
294 	struct dentry *root = sb->s_root, *subdir, *tmp;  in afs_dynroot_depopulate()
297 	mutex_lock(&net->proc_cells_lock);  in afs_dynroot_depopulate()
298 	if (net->dynroot_sb == sb)  in afs_dynroot_depopulate()
299 		net->dynroot_sb = NULL;  in afs_dynroot_depopulate()
300 	mutex_unlock(&net->proc_cells_lock);  in afs_dynroot_depopulate()
303 		inode_lock(root->d_inode);  in afs_dynroot_depopulate()
306 		list_for_each_entry_safe(subdir, tmp, &root->d_subdirs, d_child) {  in afs_dynroot_depopulate()
307 			if (subdir->d_fsdata) {  in afs_dynroot_depopulate()
308 				subdir->d_fsdata = NULL;  in afs_dynroot_depopulate()
313 		inode_unlock(root->d_inode);  in afs_dynroot_depopulate()