locks/nfsd: allocate file lock outside of spinlock

As suggested by Christoph Hellwig, this moves allocation
of new file locks out of generic_setlease into the
callers, nfs4_open_delegation and fcntl_setlease in order
to allow GFP_KERNEL allocations when lock_flocks has
become a spinlock.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index bb20373..8d7de08 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1113,6 +1113,7 @@
 
 /* fs/locks.c */
 extern void locks_init_lock(struct file_lock *);
+extern struct file_lock * locks_alloc_lock(void);
 extern void locks_copy_lock(struct file_lock *, struct file_lock *);
 extern void __locks_copy_lock(struct file_lock *, const struct file_lock *);
 extern void locks_remove_posix(struct file *, fl_owner_t);