28 static bool is_empty_dir(struct ctl_table_header *head)  in is_empty_dir()  argument
30 	return head->ctl_table[0].child == sysctl_mount_point;  in is_empty_dir()
76 static int insert_links(struct ctl_table_header *head);
105 	struct ctl_table_header *head;  in find_entry()  local
116 		head = ctl_node->header;  in find_entry()
117 		entry = &head->ctl_table[ctl_node - head->node];  in find_entry()
126 			*phead = head;  in find_entry()
133 static int insert_entry(struct ctl_table_header *head, struct ctl_table *entry)  in insert_entry()  argument
135 	struct rb_node *node = &head->node[entry - head->ctl_table].node;  in insert_entry()
136 	struct rb_node **p = &head->parent->root.rb_node;  in insert_entry()
161 			sysctl_print_dir(head->parent);  in insert_entry()
168 	rb_insert_color(node, &head->parent->root);  in insert_entry()
172 static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)  in erase_entry()  argument
174 	struct rb_node *node = &head->node[entry - head->ctl_table].node;  in erase_entry()
176 	rb_erase(node, &head->parent->root);  in erase_entry()
179 static void init_header(struct ctl_table_header *head,  in init_header()  argument
183 	head->ctl_table = table;  in init_header()
184 	head->ctl_table_arg = table;  in init_header()
185 	head->used = 0;  in init_header()
186 	head->count = 1;  in init_header()
187 	head->nreg = 1;  in init_header()
188 	head->unregistering = NULL;  in init_header()
189 	head->root = root;  in init_header()
190 	head->set = set;  in init_header()
191 	head->parent = NULL;  in init_header()
192 	head->node = node;  in init_header()
196 			node->header = head;  in init_header()
200 static void erase_header(struct ctl_table_header *head)  in erase_header()  argument
203 	for (entry = head->ctl_table; entry->procname; entry++)  in erase_header()
204 		erase_entry(head, entry);  in erase_header()
287 static void sysctl_head_get(struct ctl_table_header *head)  in sysctl_head_get()  argument
290 	head->count++;  in sysctl_head_get()
294 void sysctl_head_put(struct ctl_table_header *head)  in sysctl_head_put()  argument
297 	if (!--head->count)  in sysctl_head_put()
298 		kfree_rcu(head, rcu);  in sysctl_head_put()
302 static struct ctl_table_header *sysctl_head_grab(struct ctl_table_header *head)  in sysctl_head_grab()  argument
304 	BUG_ON(!head);  in sysctl_head_grab()
306 	if (!use_table(head))  in sysctl_head_grab()
307 		head = ERR_PTR(-ENOENT);  in sysctl_head_grab()
309 	return head;  in sysctl_head_grab()
312 static void sysctl_head_finish(struct ctl_table_header *head)  in sysctl_head_finish()  argument
314 	if (!head)  in sysctl_head_finish()
317 	unuse_table(head);  in sysctl_head_finish()
334 	struct ctl_table_header *head;  in lookup_entry()  local
338 	entry = find_entry(&head, dir, name, namelen);  in lookup_entry()
339 	if (entry && use_table(head))  in lookup_entry()
340 		*phead = head;  in lookup_entry()
362 	struct ctl_table_header *head = NULL;  in first_entry()  local
370 		head = ctl_node->header;  in first_entry()
371 		entry = &head->ctl_table[ctl_node - head->node];  in first_entry()
373 	*phead = head;  in first_entry()
379 	struct ctl_table_header *head = *phead;  in next_entry()  local
381 	struct ctl_node *ctl_node = &head->node[entry - head->ctl_table];  in next_entry()
384 	unuse_table(head);  in next_entry()
388 	head = NULL;  in next_entry()
390 		head = ctl_node->header;  in next_entry()
391 		entry = &head->ctl_table[ctl_node - head->node];  in next_entry()
393 	*phead = head;  in next_entry()
417 static int sysctl_perm(struct ctl_table_header *head, struct ctl_table *table, int op)  in sysctl_perm()  argument
419 	struct ctl_table_root *root = head->root;  in sysctl_perm()
423 		mode = root->permissions(head, table);  in sysctl_perm()
431 		struct ctl_table_header *head, struct ctl_table *table)  in proc_sys_make_inode()  argument
442 	sysctl_head_get(head);  in proc_sys_make_inode()
444 	ei->sysctl = head;  in proc_sys_make_inode()
457 		if (is_empty_dir(head))  in proc_sys_make_inode()
466 	struct ctl_table_header *head = PROC_I(inode)->sysctl;  in grab_header()  local
467 	if (!head)  in grab_header()
468 		head = &sysctl_table_root.default_set.dir.header;  in grab_header()
469 	return sysctl_head_grab(head);  in grab_header()
475 	struct ctl_table_header *head = grab_header(dir);  in proc_sys_lookup()  local
484 	if (IS_ERR(head))  in proc_sys_lookup()
485 		return ERR_CAST(head);  in proc_sys_lookup()
487 	ctl_dir = container_of(head, struct ctl_dir, header);  in proc_sys_lookup()
501 	inode = proc_sys_make_inode(dir->i_sb, h ? h : head, p);  in proc_sys_lookup()
512 	sysctl_head_finish(head);  in proc_sys_lookup()
520 	struct ctl_table_header *head = grab_header(inode);  in proc_sys_call_handler()  local
525 	if (IS_ERR(head))  in proc_sys_call_handler()
526 		return PTR_ERR(head);  in proc_sys_call_handler()
533 	if (sysctl_perm(head, table, write ? MAY_WRITE : MAY_READ))  in proc_sys_call_handler()
547 	sysctl_head_finish(head);  in proc_sys_call_handler()
566 	struct ctl_table_header *head = grab_header(inode);  in proc_sys_open()  local
570 	if (IS_ERR(head))  in proc_sys_open()
571 		return PTR_ERR(head);  in proc_sys_open()
576 	sysctl_head_finish(head);  in proc_sys_open()
584 	struct ctl_table_header *head = grab_header(inode);  in proc_sys_poll()  local
590 	if (IS_ERR(head))  in proc_sys_poll()
608 	sysctl_head_finish(head);  in proc_sys_poll()
615 				struct ctl_table_header *head,  in proc_sys_fill_cache()  argument
632 			inode = proc_sys_make_inode(dir->d_sb, head, table);  in proc_sys_fill_cache()
653 				    struct ctl_table_header *head,  in proc_sys_link_fill_cache()  argument
657 	head = sysctl_head_grab(head);  in proc_sys_link_fill_cache()
661 		int err = sysctl_follow_link(&head, &table, current->nsproxy);  in proc_sys_link_fill_cache()
666 	ret = proc_sys_fill_cache(file, ctx, head, table);  in proc_sys_link_fill_cache()
668 	sysctl_head_finish(head);  in proc_sys_link_fill_cache()
672 static int scan(struct ctl_table_header *head, struct ctl_table *table,  in scan()  argument
682 		res = proc_sys_link_fill_cache(file, ctx, head, table);  in scan()
684 		res = proc_sys_fill_cache(file, ctx, head, table);  in scan()
694 	struct ctl_table_header *head = grab_header(file_inode(file));  in proc_sys_readdir()  local
700 	if (IS_ERR(head))  in proc_sys_readdir()
701 		return PTR_ERR(head);  in proc_sys_readdir()
703 	ctl_dir = container_of(head, struct ctl_dir, header);  in proc_sys_readdir()
716 	sysctl_head_finish(head);  in proc_sys_readdir()
726 	struct ctl_table_header *head;  in proc_sys_permission()  local
734 	head = grab_header(inode);  in proc_sys_permission()
735 	if (IS_ERR(head))  in proc_sys_permission()
736 		return PTR_ERR(head);  in proc_sys_permission()
742 		error = sysctl_perm(head, table, mask & ~MAY_NOT_BLOCK);  in proc_sys_permission()
744 	sysctl_head_finish(head);  in proc_sys_permission()
768 	struct ctl_table_header *head = grab_header(inode);  in proc_sys_getattr()  local
771 	if (IS_ERR(head))  in proc_sys_getattr()
772 		return PTR_ERR(head);  in proc_sys_getattr()
778 	sysctl_head_finish(head);  in proc_sys_getattr()
839 	struct ctl_table_header *head;  in proc_sys_compare()  local
852 	head = rcu_dereference(PROC_I(inode)->sysctl);  in proc_sys_compare()
853 	return !head || !sysctl_is_seen(head);  in proc_sys_compare()
865 	struct ctl_table_header *head;  in find_subdir()  local
868 	entry = find_entry(&head, dir, name, namelen);  in find_subdir()
873 	return container_of(head, struct ctl_dir, header);  in find_subdir()
980 	struct ctl_table_header *head;  in sysctl_follow_link()  local
996 		head = NULL;  in sysctl_follow_link()
997 		entry = find_entry(&head, dir, procname, strlen(procname));  in sysctl_follow_link()
999 		if (entry && use_table(head)) {  in sysctl_follow_link()
1001 			*phead = head;  in sysctl_follow_link()
1103 	struct ctl_table_header *head;  in get_links()  local
1109 		link = find_entry(&head, dir, procname, strlen(procname));  in get_links()
1122 		link = find_entry(&head, dir, procname, strlen(procname));  in get_links()
1123 		head->nreg++;  in get_links()
1128 static int insert_links(struct ctl_table_header *head)  in insert_links()  argument
1135 	if (head->set == root_set)  in insert_links()
1138 	core_parent = xlate_dir(root_set, head->parent);  in insert_links()
1142 	if (get_links(core_parent, head->ctl_table, head->root))  in insert_links()
1148 	links = new_links(core_parent, head->ctl_table, head->root);  in insert_links()
1156 	if (get_links(core_parent, head->ctl_table, head->root)) {  in insert_links()