From 74be0cc82835aecad332a29896b0f212ba893403 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 17 Dec 2009 21:24:22 -0500 Subject: [PATCH] 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 --- fs/notify/dnotify/dnotify.c | 3 +- fs/notify/group.c | 48 ++------------------------------ fs/notify/inotify/inotify_user.c | 11 +------- include/linux/fsnotify_backend.h | 10 +------ kernel/audit_tree.c | 3 +- kernel/audit_watch.c | 2 +- 6 files changed, 7 insertions(+), 70 deletions(-) diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c index a213b83a59c..1f46aeac338 100644 --- 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 777ca821225..62fb8961a57 100644 --- 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 cbe16df326f..cae317f5bd9 100644 --- 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 @@ -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 427f6ffab12..57e503d017c 100644 --- 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 e3d63b596ef..59065e72a2e 100644 --- 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 85c43aa292e..c500104d38c 100644 --- 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; -- 2.39.3