JFS: Fix race in txLock

TxAnchor.anon_list is protected by jfsTxnLock (TXN_LOCK), but there was
a place in txLock() that was removing an entry from the list without holding
the spinlock.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>

fs/jfs/jfs_txnmgr.c

@@ -657,7 +657,9 @@ struct tlock *txLock(tid_t tid, struct inode *ip, struct metapage * mp,
 				/* only anonymous txn.
 				 * Remove from anon_list
 				 */
+				TXN_LOCK();
 				list_del_init(&jfs_ip->anon_inode_list);
+				TXN_UNLOCK();
 			}
 			jfs_ip->atlhead = tlck->next;
 		} else {

fs/jfs/super.c

@@ -114,6 +114,8 @@ static void jfs_destroy_inode(struct inode *inode)
 {
 	struct jfs_inode_info *ji = JFS_IP(inode);
 
+	BUG_ON(!list_empty(&ji->anon_inode_list));
+
 	spin_lock_irq(&ji->ag_lock);
 	if (ji->active_ag != -1) {
 		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;