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>

2 files changed, 4 insertions, 0 deletions

diff --git a/fs/jfs/jfs_txnmgr.c b/fs/jfs/jfs_txnmgr.c
index 3555acff12d0..c7a92f9deb2b 100644
--- a/fs/jfs/jfs_txnmgr.c
+++ b/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 {
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index c2abdaee0c0b..9ff89720f93b 100644
--- a/fs/jfs/super.c
+++ b/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;