proc: Rename in proc_inode rename sysctl_inodes sibling_inodes

I about to need and use the same functionality for pid based
inodes and there is no point in adding a second field when
this field is already here and serving the same purporse.

Just give the field a generic name so it is clear that
it is no longer sysctl specific.

Also for good measure initialize sibling_inodes when
proc_inode is initialized.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

fs/proc/inode.c

@@ -68,6 +68,7 @@ static struct inode *proc_alloc_inode(struct super_block *sb)
 	ei->pde = NULL;
 	ei->sysctl = NULL;
 	ei->sysctl_entry = NULL;
+	INIT_HLIST_NODE(&ei->sibling_inodes);
 	ei->ns_ops = NULL;
 	return &ei->vfs_inode;
 }

fs/proc/internal.h

@@ -91,7 +91,7 @@ struct proc_inode {
 	struct proc_dir_entry *pde;
 	struct ctl_table_header *sysctl;
 	struct ctl_table *sysctl_entry;
-	struct hlist_node sysctl_inodes;
+	struct hlist_node sibling_inodes;
 	const struct proc_ns_operations *ns_ops;
 	struct inode vfs_inode;
 } __randomize_layout;

fs/proc/proc_sysctl.c

@@ -279,9 +279,9 @@ static void proc_sys_prune_dcache(struct ctl_table_header *head)
 		node = hlist_first_rcu(&head->inodes);
 		if (!node)
 			break;
-		ei = hlist_entry(node, struct proc_inode, sysctl_inodes);
+		ei = hlist_entry(node, struct proc_inode, sibling_inodes);
 		spin_lock(&sysctl_lock);
-		hlist_del_init_rcu(&ei->sysctl_inodes);
+		hlist_del_init_rcu(&ei->sibling_inodes);
 		spin_unlock(&sysctl_lock);
 
 		inode = &ei->vfs_inode;
@@ -483,7 +483,7 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
 	}
 	ei->sysctl = head;
 	ei->sysctl_entry = table;
-	hlist_add_head_rcu(&ei->sysctl_inodes, &head->inodes);
+	hlist_add_head_rcu(&ei->sibling_inodes, &head->inodes);
 	head->count++;
 	spin_unlock(&sysctl_lock);
 
@@ -514,7 +514,7 @@ static struct inode *proc_sys_make_inode(struct super_block *sb,
 void proc_sys_evict_inode(struct inode *inode, struct ctl_table_header *head)
 {
 	spin_lock(&sysctl_lock);
-	hlist_del_init_rcu(&PROC_I(inode)->sysctl_inodes);
+	hlist_del_init_rcu(&PROC_I(inode)->sibling_inodes);
 	if (!--head->count)
 		kfree_rcu(head, rcu);
 	spin_unlock(&sysctl_lock);