1 files changed, 68 insertions, 5 deletions

diff --git a/fs/locks.c b/fs/locks.c
index 686eae21daf6..6970f55daf54 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -212,6 +212,7 @@ struct file_lock_list_struct {
 static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list);
 DEFINE_STATIC_PERCPU_RWSEM(file_rwsem);
 
+
 /*
  * The blocked_hash is used to find POSIX lock loops for deadlock detection.
  * It is protected by blocked_lock_lock.
@@ -1592,7 +1593,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
 	ctx = smp_load_acquire(&inode->i_flctx);
 	if (!ctx) {
 		WARN_ON_ONCE(1);
-		return error;
+		goto free_lock;
 	}
 
 	percpu_down_read(&file_rwsem);
@@ -1672,6 +1673,7 @@ out:
 	spin_unlock(&ctx->flc_lock);
 	percpu_up_read(&file_rwsem);
 	locks_dispose_list(&dispose);
+free_lock:
 	locks_free_lock(new_fl);
 	return error;
 }
@@ -1990,6 +1992,64 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
 }
 EXPORT_SYMBOL(generic_setlease);
 
+#if IS_ENABLED(CONFIG_SRCU)
+/*
+ * Kernel subsystems can register to be notified on any attempt to set
+ * a new lease with the lease_notifier_chain. This is used by (e.g.) nfsd
+ * to close files that it may have cached when there is an attempt to set a
+ * conflicting lease.
+ */
+static struct srcu_notifier_head lease_notifier_chain;
+
+static inline void
+lease_notifier_chain_init(void)
+{
+	srcu_init_notifier_head(&lease_notifier_chain);
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+	if (arg != F_UNLCK)
+		srcu_notifier_call_chain(&lease_notifier_chain, arg, lease);
+}
+
+int lease_register_notifier(struct notifier_block *nb)
+{
+	return srcu_notifier_chain_register(&lease_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(lease_register_notifier);
+
+void lease_unregister_notifier(struct notifier_block *nb)
+{
+	srcu_notifier_chain_unregister(&lease_notifier_chain, nb);
+}
+EXPORT_SYMBOL_GPL(lease_unregister_notifier);
+
+#else /* !IS_ENABLED(CONFIG_SRCU) */
+static inline void
+lease_notifier_chain_init(void)
+{
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+}
+
+int lease_register_notifier(struct notifier_block *nb)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(lease_register_notifier);
+
+void lease_unregister_notifier(struct notifier_block *nb)
+{
+}
+EXPORT_SYMBOL_GPL(lease_unregister_notifier);
+
+#endif /* IS_ENABLED(CONFIG_SRCU) */
+
 /**
  * vfs_setlease        -       sets a lease on an open file
  * @filp:	file pointer
@@ -2010,6 +2070,8 @@ EXPORT_SYMBOL(generic_setlease);
 int
 vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
 {
+	if (lease)
+		setlease_notifier(arg, *lease);
 	if (filp->f_op->setlease)
 		return filp->f_op->setlease(filp, arg, lease, priv);
 	else
@@ -2784,10 +2846,10 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
 			       ? (fl->fl_type & LOCK_WRITE) ? "RW   " : "READ "
 			       : (fl->fl_type & LOCK_WRITE) ? "WRITE" : "NONE ");
 	} else {
-		seq_printf(f, "%s ",
-			       (lease_breaking(fl))
-			       ? (fl->fl_type == F_UNLCK) ? "UNLCK" : "READ "
-			       : (fl->fl_type == F_WRLCK) ? "WRITE" : "READ ");
+		int type = IS_LEASE(fl) ? target_leasetype(fl) : fl->fl_type;
+
+		seq_printf(f, "%s ", (type == F_WRLCK) ? "WRITE" :
+				     (type == F_RDLCK) ? "READ" : "UNLCK");
 	}
 	if (inode) {
 		/* userspace relies on this representation of dev_t */
@@ -2923,6 +2985,7 @@ static int __init filelock_init(void)
 		INIT_HLIST_HEAD(&fll->hlist);
 	}
 
+	lease_notifier_chain_init();
 	return 0;
 }
 core_initcall(filelock_init);