diff options
| -rw-r--r-- | fs/notify/mark.c | 66 | ||||
| -rw-r--r-- | include/linux/fsnotify_backend.h | 5 |
2 files changed, 53 insertions, 18 deletions
diff --git a/fs/notify/mark.c b/fs/notify/mark.c index cfcbf114676e..fc0df4442f7b 100644 --- a/fs/notify/mark.c +++ b/fs/notify/mark.c @@ -92,6 +92,9 @@ #include "fsnotify.h" struct srcu_struct fsnotify_mark_srcu; +static DEFINE_SPINLOCK(destroy_lock); +static LIST_HEAD(destroy_list); +static DECLARE_WAIT_QUEUE_HEAD(destroy_waitq); void fsnotify_get_mark(struct fsnotify_mark *mark) { @@ -165,19 +168,10 @@ void fsnotify_detach_mark(struct fsnotify_mark *mark) atomic_dec(&group->num_marks); } -static void -fsnotify_mark_free_rcu(struct rcu_head *rcu) -{ - struct fsnotify_mark *mark; - - mark = container_of(rcu, struct fsnotify_mark, g_rcu); - fsnotify_put_mark(mark); -} - /* - * Free fsnotify mark. The freeing is actually happening from a call_srcu - * callback. Caller must have a reference to the mark or be protected by - * fsnotify_mark_srcu. + * Free fsnotify mark. The freeing is actually happening from a kthread which + * first waits for srcu period end. Caller must have a reference to the mark + * or be protected by fsnotify_mark_srcu. */ void fsnotify_free_mark(struct fsnotify_mark *mark) { @@ -192,7 +186,10 @@ void fsnotify_free_mark(struct fsnotify_mark *mark) mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE; spin_unlock(&mark->lock); - call_srcu(&fsnotify_mark_srcu, &mark->g_rcu, fsnotify_mark_free_rcu); + spin_lock(&destroy_lock); + list_add(&mark->g_list, &destroy_list); + spin_unlock(&destroy_lock); + wake_up(&destroy_waitq); /* * Some groups like to know that marks are being freed. This is a @@ -388,7 +385,11 @@ err: spin_unlock(&mark->lock); - call_srcu(&fsnotify_mark_srcu, &mark->g_rcu, fsnotify_mark_free_rcu); + spin_lock(&destroy_lock); + list_add(&mark->g_list, &destroy_list); + spin_unlock(&destroy_lock); + wake_up(&destroy_waitq); + return ret; } @@ -491,3 +492,40 @@ void fsnotify_init_mark(struct fsnotify_mark *mark, atomic_set(&mark->refcnt, 1); mark->free_mark = free_mark; } + +static int fsnotify_mark_destroy(void *ignored) +{ + struct fsnotify_mark *mark, *next; + struct list_head private_destroy_list; + + for (;;) { + spin_lock(&destroy_lock); + /* exchange the list head */ + list_replace_init(&destroy_list, &private_destroy_list); + spin_unlock(&destroy_lock); + + synchronize_srcu(&fsnotify_mark_srcu); + + list_for_each_entry_safe(mark, next, &private_destroy_list, g_list) { + list_del_init(&mark->g_list); + fsnotify_put_mark(mark); + } + + wait_event_interruptible(destroy_waitq, !list_empty(&destroy_list)); + } + + return 0; +} + +static int __init fsnotify_mark_init(void) +{ + struct task_struct *thread; + + thread = kthread_run(fsnotify_mark_destroy, NULL, + "fsnotify_mark"); + if (IS_ERR(thread)) + panic("unable to start fsnotify mark destruction thread."); + + return 0; +} +device_initcall(fsnotify_mark_init); diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index 6b7e89f45aa4..533c4408529a 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -220,10 +220,7 @@ struct fsnotify_mark { /* 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. [group->mark_mutex] */ - union { - struct list_head g_list; - struct rcu_head g_rcu; - }; + struct list_head g_list; /* Protects inode / mnt pointers, flags, masks */ spinlock_t lock; /* List of marks for inode / vfsmount [obj_lock] */ |