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authorKent Overstreet <kent.overstreet@gmail.com>2017-03-19 15:56:34 -0800
committerKent Overstreet <kent.overstreet@gmail.com>2017-03-19 17:31:47 -0800
commit5ec39af8eaba49aee7bafa44c661da39e2f40dc3 (patch)
tree1fb1a981602cbf22c7d2b2dba1168c715d7cecb5 /linux/closure.c
parentbb1941de5378a7b8122d3575dcbc7d0aeb6326f0 (diff)
Rename from bcache-tools to bcachefs-tools
Diffstat (limited to 'linux/closure.c')
-rw-r--r--linux/closure.c211
1 files changed, 211 insertions, 0 deletions
diff --git a/linux/closure.c b/linux/closure.c
new file mode 100644
index 00000000..26a29356
--- /dev/null
+++ b/linux/closure.c
@@ -0,0 +1,211 @@
+/*
+ * Asynchronous refcounty things
+ *
+ * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
+ * Copyright 2012 Google, Inc.
+ */
+
+#include <linux/closure.h>
+#include <linux/debugfs.h>
+#include <linux/export.h>
+#include <linux/seq_file.h>
+
+static inline void closure_put_after_sub(struct closure *cl, int flags)
+{
+ int r = flags & CLOSURE_REMAINING_MASK;
+
+ BUG_ON(flags & CLOSURE_GUARD_MASK);
+ BUG_ON(!r && (flags & ~CLOSURE_DESTRUCTOR));
+
+ if (!r) {
+ if (cl->fn && !(flags & CLOSURE_DESTRUCTOR)) {
+ atomic_set(&cl->remaining,
+ CLOSURE_REMAINING_INITIALIZER);
+ closure_queue(cl);
+ } else {
+ struct closure *parent = cl->parent;
+ closure_fn *destructor = cl->fn;
+
+ closure_debug_destroy(cl);
+
+ if (destructor)
+ destructor(cl);
+
+ if (parent)
+ closure_put(parent);
+ }
+ }
+}
+
+/* For clearing flags with the same atomic op as a put */
+void closure_sub(struct closure *cl, int v)
+{
+ closure_put_after_sub(cl, atomic_sub_return(v, &cl->remaining));
+}
+EXPORT_SYMBOL(closure_sub);
+
+/**
+ * closure_put - decrement a closure's refcount
+ */
+void closure_put(struct closure *cl)
+{
+ closure_put_after_sub(cl, atomic_dec_return(&cl->remaining));
+}
+EXPORT_SYMBOL(closure_put);
+
+/**
+ * closure_wake_up - wake up all closures on a wait list, without memory barrier
+ */
+void __closure_wake_up(struct closure_waitlist *wait_list)
+{
+ struct llist_node *list, *next;
+ struct closure *cl;
+
+ /*
+ * Grab entire list, reverse order to preserve FIFO ordering, and wake
+ * everything up
+ */
+ for (list = llist_reverse_order(llist_del_all(&wait_list->list));
+ list;
+ list = next) {
+ next = llist_next(list);
+ cl = container_of(list, struct closure, list);
+
+ closure_set_waiting(cl, 0);
+ closure_sub(cl, CLOSURE_WAITING + 1);
+ }
+}
+EXPORT_SYMBOL(__closure_wake_up);
+
+/**
+ * closure_wait - add a closure to a waitlist
+ *
+ * @waitlist will own a ref on @cl, which will be released when
+ * closure_wake_up() is called on @waitlist.
+ *
+ */
+bool closure_wait(struct closure_waitlist *waitlist, struct closure *cl)
+{
+ if (atomic_read(&cl->remaining) & CLOSURE_WAITING)
+ return false;
+
+ closure_set_waiting(cl, _RET_IP_);
+ atomic_add(CLOSURE_WAITING + 1, &cl->remaining);
+ llist_add(&cl->list, &waitlist->list);
+
+ return true;
+}
+EXPORT_SYMBOL(closure_wait);
+
+struct closure_syncer {
+ struct task_struct *task;
+ int done;
+};
+
+static void closure_sync_fn(struct closure *cl)
+{
+ cl->s->done = 1;
+ wake_up_process(cl->s->task);
+}
+
+void __sched __closure_sync(struct closure *cl)
+{
+ struct closure_syncer s = { .task = current };
+
+ cl->s = &s;
+ continue_at_noreturn(cl, closure_sync_fn, NULL);
+
+ while (1) {
+ __set_current_state(TASK_UNINTERRUPTIBLE);
+ smp_mb();
+ if (s.done)
+ break;
+ schedule();
+ }
+
+ __set_current_state(TASK_RUNNING);
+}
+EXPORT_SYMBOL(__closure_sync);
+
+#ifdef CONFIG_DEBUG_CLOSURES
+
+static LIST_HEAD(closure_list);
+static DEFINE_SPINLOCK(closure_list_lock);
+
+void closure_debug_create(struct closure *cl)
+{
+ unsigned long flags;
+
+ BUG_ON(cl->magic == CLOSURE_MAGIC_ALIVE);
+ cl->magic = CLOSURE_MAGIC_ALIVE;
+
+ spin_lock_irqsave(&closure_list_lock, flags);
+ list_add(&cl->all, &closure_list);
+ spin_unlock_irqrestore(&closure_list_lock, flags);
+}
+EXPORT_SYMBOL(closure_debug_create);
+
+void closure_debug_destroy(struct closure *cl)
+{
+ unsigned long flags;
+
+ BUG_ON(cl->magic != CLOSURE_MAGIC_ALIVE);
+ cl->magic = CLOSURE_MAGIC_DEAD;
+
+ spin_lock_irqsave(&closure_list_lock, flags);
+ list_del(&cl->all);
+ spin_unlock_irqrestore(&closure_list_lock, flags);
+}
+EXPORT_SYMBOL(closure_debug_destroy);
+
+static struct dentry *debug;
+
+static int debug_seq_show(struct seq_file *f, void *data)
+{
+ struct closure *cl;
+
+ spin_lock_irq(&closure_list_lock);
+
+ list_for_each_entry(cl, &closure_list, all) {
+ int r = atomic_read(&cl->remaining);
+
+ seq_printf(f, "%p: %pF -> %pf p %p r %i ",
+ cl, (void *) cl->ip, cl->fn, cl->parent,
+ r & CLOSURE_REMAINING_MASK);
+
+ seq_printf(f, "%s%s\n",
+ test_bit(WORK_STRUCT_PENDING_BIT,
+ work_data_bits(&cl->work)) ? "Q" : "",
+ r & CLOSURE_RUNNING ? "R" : "");
+
+ if (r & CLOSURE_WAITING)
+ seq_printf(f, " W %pF\n",
+ (void *) cl->waiting_on);
+
+ seq_puts(f, "\n");
+ }
+
+ spin_unlock_irq(&closure_list_lock);
+ return 0;
+}
+
+static int debug_seq_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, debug_seq_show, NULL);
+}
+
+static const struct file_operations debug_ops = {
+ .owner = THIS_MODULE,
+ .open = debug_seq_open,
+ .read = seq_read,
+ .release = single_release
+};
+
+static int __init closure_debug_init(void)
+{
+ debug = debugfs_create_file("closures", 0400, NULL, NULL, &debug_ops);
+ return 0;
+}
+late_initcall(closure_debug_init)
+
+#endif