fail_page_alloc: simplify debugfs initialization

Now cleanup_fault_attr_dentries() recursively removes a directory, So we
can simplify the error handling in the initialization code and no need
to hold dentry structs for each debugfs file.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 72c6820..1dbcf88 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1370,21 +1370,12 @@ failed:
 
 #ifdef CONFIG_FAIL_PAGE_ALLOC
 
-static struct fail_page_alloc_attr {
+static struct {
        struct fault_attr attr;
 
        u32 ignore_gfp_highmem;
        u32 ignore_gfp_wait;
        u32 min_order;
-
-#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
-
-       struct dentry *ignore_gfp_highmem_file;
-       struct dentry *ignore_gfp_wait_file;
-       struct dentry *min_order_file;
-
-#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
-
 } fail_page_alloc = {
        .attr = FAULT_ATTR_INITIALIZER,
        .ignore_gfp_wait = 1,
@@ -1424,30 +1415,24 @@ static int __init fail_page_alloc_debugfs(void)
                                       "fail_page_alloc");
        if (err)
                return err;
+
        dir = fail_page_alloc.attr.dir;
 
-       fail_page_alloc.ignore_gfp_wait_file =
-               debugfs_create_bool("ignore-gfp-wait", mode, dir,
-                                     &fail_page_alloc.ignore_gfp_wait);
-
-       fail_page_alloc.ignore_gfp_highmem_file =
-               debugfs_create_bool("ignore-gfp-highmem", mode, dir,
-                                     &fail_page_alloc.ignore_gfp_highmem);
-       fail_page_alloc.min_order_file =
-               debugfs_create_u32("min-order", mode, dir,
-                                  &fail_page_alloc.min_order);
-
-       if (!fail_page_alloc.ignore_gfp_wait_file ||
-            !fail_page_alloc.ignore_gfp_highmem_file ||
-            !fail_page_alloc.min_order_file) {
-               err = -ENOMEM;
-               debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
-               debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
-               debugfs_remove(fail_page_alloc.min_order_file);
-               cleanup_fault_attr_dentries(&fail_page_alloc.attr);
-       }
+       if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
+                               &fail_page_alloc.ignore_gfp_wait))
+               goto fail;
+       if (!debugfs_create_bool("ignore-gfp-highmem", mode, dir,
+                               &fail_page_alloc.ignore_gfp_highmem))
+               goto fail;
+       if (!debugfs_create_u32("min-order", mode, dir,
+                               &fail_page_alloc.min_order))
+               goto fail;
+
+       return 0;
+fail:
+       cleanup_fault_attr_dentries(&fail_page_alloc.attr);
 
-       return err;
+       return -ENOMEM;
 }
 
 late_initcall(fail_page_alloc_debugfs);