From 37d469e7673a663cbf38360beb1eaa3224c9d272 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Fri, 12 Dec 2014 16:58:39 -0800 Subject: [PATCH] fsnotify: remove destroy_list from fsnotify_mark destroy_list is used to track marks which still need waiting for srcu period end before they can be freed. However by the time mark is added to destroy_list it isn't in group's list of marks anymore and thus we can reuse fsnotify_mark->g_list for queueing into destroy_list. This saves two pointers for each fsnotify_mark. Signed-off-by: Jan Kara Cc: Eric Paris Cc: Heinrich Schuchardt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/notify/mark.c | 8 ++++---- include/linux/fsnotify_backend.h | 7 +++++-- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/fs/notify/mark.c b/fs/notify/mark.c index 3942d5c9eb8d..92e48c70f0f0 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -161,7 +161,7 @@ void fsnotify_destroy_mark_locked(struct fsnotify_mark *mark, mutex_unlock(&group->mark_mutex); spin_lock(&destroy_lock); - list_add(&mark->destroy_list, &destroy_list); + list_add(&mark->g_list, &destroy_list); spin_unlock(&destroy_lock); wake_up(&destroy_waitq); /* @@ -370,7 +370,7 @@ err: spin_unlock(&mark->lock); spin_lock(&destroy_lock); - list_add(&mark->destroy_list, &destroy_list); + list_add(&mark->g_list, &destroy_list); spin_unlock(&destroy_lock); wake_up(&destroy_waitq); @@ -469,8 +469,8 @@ static int fsnotify_mark_destroy(void *ignored) synchronize_srcu(&fsnotify_mark_srcu); - list_for_each_entry_safe(mark, next, &private_destroy_list, destroy_list) { - list_del_init(&mark->destroy_list); + list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) { + list_del_init(&mark->g_list); fsnotify_put_mark(mark); } diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 442847a02b8f..0f313f93c586 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -212,7 +212,11 @@ struct fsnotify_mark { * in kernel that found and may be using this mark. */ atomic_t refcnt; /* active things looking at this mark */ struct fsnotify_group *group; /* group this mark is for */ - struct list_head g_list; /* list of marks by group->i_fsnotify_marks */ + struct list_head g_list; /* list of marks by group->i_fsnotify_marks + * Also reused for queueing mark into + * destroy_list when it's waiting for + * the end of SRCU period before it can + * be freed */ spinlock_t lock; /* protect group and inode */ struct hlist_node obj_list; /* list of marks for inode / vfsmount */ struct list_head free_list; /* tmp list used when freeing this mark */ @@ -227,7 +231,6 @@ struct fsnotify_mark { #define FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY 0x08 #define FSNOTIFY_MARK_FLAG_ALIVE 0x10 unsigned int flags; /* vfsmount or inode mark? */ - struct list_head destroy_list; void (*free_mark)(struct fsnotify_mark *mark); /* called on final put+free */ };