page cache: Finish XArray conversion

With no more radix tree API users left, we can drop the GFP flags
and use xa_init() instead of INIT_RADIX_TREE().
Signed-off-by: Matthew Wilcox <willy@infradead.org>

fs/inode.c

@@ -349,7 +349,7 @@ EXPORT_SYMBOL(inc_nlink);
 
 static void __address_space_init_once(struct address_space *mapping)
 {
-	INIT_RADIX_TREE(&mapping->i_pages, GFP_ATOMIC | __GFP_ACCOUNT);
+	xa_init_flags(&mapping->i_pages, XA_FLAGS_LOCK_IRQ);
 	init_rwsem(&mapping->i_mmap_rwsem);
 	INIT_LIST_HEAD(&mapping->private_list);
 	spin_lock_init(&mapping->private_lock);

mm/swap_state.c

@@ -586,7 +586,7 @@ int init_swap_address_space(unsigned int type, unsigned long nr_pages)
 		return -ENOMEM;
 	for (i = 0; i < nr; i++) {
 		space = spaces + i;
-		INIT_RADIX_TREE(&space->i_pages, GFP_ATOMIC|__GFP_NOWARN);
+		xa_init_flags(&space->i_pages, XA_FLAGS_LOCK_IRQ);
 		atomic_set(&space->i_mmap_writable, 0);
 		space->a_ops = &swap_aops;
 		/* swap cache doesn't use writeback related tags */