Merge remote-tracking branch 'file-locks/linux-next'

[karo-tx-linux.git] / fs / locks.c

diff --git a/fs/locks.c b/fs/locks.c
index 0d2b3267e2a3eb8fefbffb3cd3f58b31fe4ed04d..ba7fcdb6fc7a641add53e4d8223d65b66991cf2e 100644 (file)
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1784,6 +1784,40 @@ 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.
+ */
+struct srcu_notifier_head lease_notifier_chain;
+EXPORT_SYMBOL_GPL(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);
+}
+#else /* !IS_ENABLED(CONFIG_SRCU) */
+static inline void
+lease_notifier_chain_init(void)
+{
+}
+
+static inline void
+setlease_notifier(long arg, struct file_lock *lease)
+{
+}
+#endif /* IS_ENABLED(CONFIG_SRCU) */
+
 /**
  * vfs_setlease        -       sets a lease on an open file
  * @filp:      file pointer
@@ -1804,6 +1838,8 @@ 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
@@ -2724,6 +2760,7 @@ static int __init filelock_init(void)
        for_each_possible_cpu(i)
                INIT_HLIST_HEAD(per_cpu_ptr(&file_lock_list, i));
 
+       lease_notifier_chain_init();
        return 0;
 }