fanotify: add BUILD_BUG_ON() to count the bits of fanotify constants

Also define the FANOTIFY_EVENT_FLAGS consisting of the extra flags
FAN_ONDIR and FAN_ON_CHILD.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 03498eb..361e3a0 100644 (file)
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -205,6 +205,8 @@ static int fanotify_handle_event(struct fsnotify_group *group,
        BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
        BUILD_BUG_ON(FAN_ONDIR != FS_ISDIR);
 
+       BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 10);
+
        if (!fanotify_should_send_event(iter_info, mask, data, data_type))
                return 0;
 

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 530e5e4..14594e4 100644 (file)
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -803,7 +803,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
        struct fsnotify_group *group;
        struct fd f;
        struct path path;
-       u32 valid_mask = FANOTIFY_EVENTS | FAN_EVENT_ON_CHILD | FAN_ONDIR;
+       u32 valid_mask = FANOTIFY_EVENTS | FANOTIFY_EVENT_FLAGS;
        unsigned int mark_type = flags & FANOTIFY_MARK_TYPE_BITS;
        int ret;
 
@@ -944,6 +944,9 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark,
  */
 static int __init fanotify_user_setup(void)
 {
+       BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 6);
+       BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9);
+
        fanotify_mark_cache = KMEM_CACHE(fsnotify_mark,
                                         SLAB_PANIC|SLAB_ACCOUNT);
        fanotify_event_cachep = KMEM_CACHE(fanotify_event_info, SLAB_PANIC);

diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index 4519b09..caf55c6 100644 (file)
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -41,11 +41,17 @@
 /* Events that require a permission response from user */
 #define FANOTIFY_PERM_EVENTS   (FAN_OPEN_PERM | FAN_ACCESS_PERM)
 
+/* Extra flags that may be reported with event or control handling of events */
+#define FANOTIFY_EVENT_FLAGS   (FAN_EVENT_ON_CHILD | FAN_ONDIR)
+
 /* Events that may be reported to user */
 #define FANOTIFY_OUTGOING_EVENTS       (FANOTIFY_EVENTS | \
                                         FANOTIFY_PERM_EVENTS | \
                                         FAN_Q_OVERFLOW)
 
+#define ALL_FANOTIFY_EVENT_BITS                (FANOTIFY_OUTGOING_EVENTS | \
+                                        FANOTIFY_EVENT_FLAGS)
+
 /* Do not use these old uapi constants internally */
 #undef FAN_ALL_CLASS_BITS
 #undef FAN_ALL_INIT_FLAGS