fsnotify: remove group_num altogether

The original fsnotify interface has a group-num which was intended to be
able to find a group after it was added.  I no longer think this is a
necessary thing to do and so we remove the group_num.

Signed-off-by: Eric Paris <eparis@redhat.com>

diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index a213b83a59cf2b25318a69770e1959339b26eaf1..1f46aeac3387f6540d545bb89e7b19f652e37c81 100644 (file)
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -433,8 +433,7 @@ static int __init dnotify_init(void)
        dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC);
        dnotify_mark_entry_cache = KMEM_CACHE(dnotify_mark_entry, SLAB_PANIC);
 
-       dnotify_group = fsnotify_obtain_group(DNOTIFY_GROUP_NUM,
-                                             0, &dnotify_fsnotify_ops);
+       dnotify_group = fsnotify_obtain_group(0, &dnotify_fsnotify_ops);
        if (IS_ERR(dnotify_group))
                panic("unable to allocate fsnotify group for dnotify\n");
        return 0;

diff --git a/fs/notify/group.c b/fs/notify/group.c
index 777ca8212255974103a5b9d8703f60d2c43a312a..62fb8961a57be13d9cb4d461788e77f704322b89 100644 (file)
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -77,15 +77,6 @@ void fsnotify_recalc_group_mask(struct fsnotify_group *group)
                fsnotify_recalc_global_mask();
 }
 
-/*
- * Take a reference to a group so things found under the fsnotify_grp_mutex
- * can't get freed under us
- */
-static void fsnotify_get_group(struct fsnotify_group *group)
-{
-       atomic_inc(&group->refcnt);
-}
-
 /*
  * Final freeing of a group
  */
@@ -170,41 +161,15 @@ void fsnotify_put_group(struct fsnotify_group *group)
        fsnotify_destroy_group(group);
 }
 
-/*
- * Simply run the fsnotify_groups list and find a group which matches
- * the given parameters.  If a group is found we take a reference to that
- * group.
- */
-static struct fsnotify_group *fsnotify_find_group(unsigned int group_num, __u32 mask,
-                                                 const struct fsnotify_ops *ops)
-{
-       struct fsnotify_group *group_iter;
-       struct fsnotify_group *group = NULL;
-
-       BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex));
-
-       list_for_each_entry_rcu(group_iter, &fsnotify_groups, group_list) {
-               if (group_iter->group_num == group_num) {
-                       if ((group_iter->mask == mask) &&
-                           (group_iter->ops == ops)) {
-                               fsnotify_get_group(group_iter);
-                               group = group_iter;
-                       } else
-                               group = ERR_PTR(-EEXIST);
-               }
-       }
-       return group;
-}
-
 /*
  * Either finds an existing group which matches the group_num, mask, and ops or
  * creates a new group and adds it to the global group list.  In either case we
  * take a reference for the group returned.
  */
-struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask,
+struct fsnotify_group *fsnotify_obtain_group(__u32 mask,
                                             const struct fsnotify_ops *ops)
 {
-       struct fsnotify_group *group, *tgroup;
+       struct fsnotify_group *group;
 
        /* very low use, simpler locking if we just always alloc */
        group = kzalloc(sizeof(struct fsnotify_group), GFP_KERNEL);
@@ -214,7 +179,6 @@ struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask,
        atomic_set(&group->refcnt, 1);
 
        group->on_group_list = 0;
-       group->group_num = group_num;
        group->mask = mask;
 
        mutex_init(&group->notification_mutex);
@@ -230,14 +194,6 @@ struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask,
        group->ops = ops;
 
        mutex_lock(&fsnotify_grp_mutex);
-       tgroup = fsnotify_find_group(group_num, mask, ops);
-       if (tgroup) {
-               /* group already exists */
-               mutex_unlock(&fsnotify_grp_mutex);
-               /* destroy the new one we made */
-               fsnotify_put_group(group);
-               return tgroup;
-       }
 
        /* group not found, add a new one */
        list_add_rcu(&group->group_list, &fsnotify_groups);

diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index cbe16df326f8df2975d162720a08fb27e4e0d0a3..cae317f5bd9dcd47125be67c27451dbc08ac5891 100644 (file)
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -51,12 +51,6 @@ int inotify_max_user_watches __read_mostly;
 static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
 struct kmem_cache *event_priv_cachep __read_mostly;
 
-/*
- * When inotify registers a new group it increments this and uses that
- * value as an offset to set the fsnotify group "name" and priority.
- */
-static atomic_t inotify_grp_num;
-
 #ifdef CONFIG_SYSCTL
 
 #include <linux/sysctl.h>
@@ -700,11 +694,8 @@ retry:
 static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsigned int max_events)
 {
        struct fsnotify_group *group;
-       unsigned int grp_num;
 
-       /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */
-       grp_num = (INOTIFY_GROUP_NUM - atomic_inc_return(&inotify_grp_num));
-       group = fsnotify_obtain_group(grp_num, 0, &inotify_fsnotify_ops);
+       group = fsnotify_obtain_group(0, &inotify_fsnotify_ops);
        if (IS_ERR(group))
                return group;
 

diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h
index 427f6ffab127dcbce004d20f28b40d396ef715b2..57e503d017c83d59ca4d8c173beff7ac1f316717 100644 (file)
--- a/include/linux/fsnotify_backend.h
+++ b/include/linux/fsnotify_backend.h
@@ -60,12 +60,6 @@
 
 #define FS_MOVE                        (FS_MOVED_FROM | FS_MOVED_TO)
 
-/* listeners that hard code group numbers near the top */
-#define DNOTIFY_GROUP_NUM      UINT_MAX
-#define AUDIT_WATCH_GROUP_NUM  (DNOTIFY_GROUP_NUM-1)
-#define AUDIT_TREE_GROUP_NUM   (AUDIT_WATCH_GROUP_NUM-1)
-#define INOTIFY_GROUP_NUM      (AUDIT_TREE_GROUP_NUM-1)
-
 struct fsnotify_group;
 struct fsnotify_event;
 struct fsnotify_mark_entry;
@@ -124,7 +118,6 @@ struct fsnotify_group {
         * closed.
         */
        atomic_t refcnt;                /* things with interest in this group */
-       unsigned int group_num;         /* simply prevents accidental group collision */
 
        const struct fsnotify_ops *ops; /* how this group handles things */
 
@@ -312,8 +305,7 @@ static inline void __fsnotify_d_instantiate(struct dentry *dentry, struct inode
 /* must call when a group changes its ->mask */
 extern void fsnotify_recalc_global_mask(void);
 /* get a reference to an existing or create a new group */
-extern struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num,
-                                                   __u32 mask,
+extern struct fsnotify_group *fsnotify_obtain_group(__u32 mask,
                                                    const struct fsnotify_ops *ops);
 /* run all marks associated with this group and update group->mask */
 extern void fsnotify_recalc_group_mask(struct fsnotify_group *group);

diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index e3d63b596ef0b14bb50f421205e157c58598898a..59065e72a2eb1f9d90f896a64e2142606c14a57d 100644 (file)
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -937,8 +937,7 @@ static int __init audit_tree_init(void)
 {
        int i;
 
-       audit_tree_group = fsnotify_obtain_group(AUDIT_TREE_GROUP_NUM,
-                                                0, &audit_tree_ops);
+       audit_tree_group = fsnotify_obtain_group(0, &audit_tree_ops);
        if (IS_ERR(audit_tree_group))
                audit_panic("cannot initialize fsnotify group for rectree watches");
 

diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c
index 85c43aa292e0b92643890c32bcb1964d631c7c31..c500104d38c20144473596e39fb0966834274e95 100644 (file)
--- a/kernel/audit_watch.c
+++ b/kernel/audit_watch.c
@@ -577,7 +577,7 @@ static const struct fsnotify_ops audit_watch_fsnotify_ops = {
 
 static int __init audit_watch_init(void)
 {
-       audit_watch_group = fsnotify_obtain_group(AUDIT_WATCH_GROUP_NUM, AUDIT_FS_WATCH,
+       audit_watch_group = fsnotify_obtain_group(AUDIT_FS_WATCH,
                                                  &audit_watch_fsnotify_ops);
        if (IS_ERR(audit_watch_group)) {
                audit_watch_group = NULL;