#include <linux/device.h>
#include <trace/events/writeback.h>
-static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
-
struct backing_dev_info noop_backing_dev_info = {
.name = "noop",
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
}
postcore_initcall(bdi_class_init);
+static int bdi_init(struct backing_dev_info *bdi);
+
static int __init default_bdi_init(void)
{
int err;
memset(wb, 0, sizeof(*wb));
+ if (wb != &bdi->wb)
+ bdi_get(bdi);
wb->bdi = bdi;
wb->last_old_flush = jiffies;
INIT_LIST_HEAD(&wb->b_dirty);
wb->dirty_sleep = jiffies;
wb->congested = wb_congested_get_create(bdi, blkcg_id, gfp);
- if (!wb->congested)
- return -ENOMEM;
+ if (!wb->congested) {
+ err = -ENOMEM;
+ goto out_put_bdi;
+ }
err = fprop_local_init_percpu(&wb->completions, gfp);
if (err)
fprop_local_destroy_percpu(&wb->completions);
out_put_cong:
wb_congested_put(wb->congested);
+out_put_bdi:
+ if (wb != &bdi->wb)
+ bdi_put(bdi);
return err;
}
+static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb);
+
/*
* Remove bdi from the global list and shutdown any threads we have running
*/
spin_lock_bh(&wb->work_lock);
if (!test_and_clear_bit(WB_registered, &wb->state)) {
spin_unlock_bh(&wb->work_lock);
+ /*
+ * Wait for wb shutdown to finish if someone else is just
+ * running wb_shutdown(). Otherwise we could proceed to wb /
+ * bdi destruction before wb_shutdown() is finished.
+ */
+ wait_on_bit(&wb->state, WB_shutting_down, TASK_UNINTERRUPTIBLE);
return;
}
+ set_bit(WB_shutting_down, &wb->state);
spin_unlock_bh(&wb->work_lock);
+ cgwb_remove_from_bdi_list(wb);
/*
* Drain work list and shutdown the delayed_work. !WB_registered
* tells wb_workfn() that @wb is dying and its work_list needs to
mod_delayed_work(bdi_wq, &wb->dwork, 0);
flush_delayed_work(&wb->dwork);
WARN_ON(!list_empty(&wb->work_list));
+ /*
+ * Make sure bit gets cleared after shutdown is finished. Matches with
+ * the barrier provided by test_and_clear_bit() above.
+ */
+ smp_wmb();
+ clear_bit(WB_shutting_down, &wb->state);
}
static void wb_exit(struct bdi_writeback *wb)
fprop_local_destroy_percpu(&wb->completions);
wb_congested_put(wb->congested);
+ if (wb != &wb->bdi->wb)
+ bdi_put(wb->bdi);
}
#ifdef CONFIG_CGROUP_WRITEBACK
/*
* cgwb_lock protects bdi->cgwb_tree, bdi->cgwb_congested_tree,
* blkcg->cgwb_list, and memcg->cgwb_list. bdi->cgwb_tree is also RCU
- * protected. cgwb_release_wait is used to wait for the completion of cgwb
- * releases from bdi destruction path.
+ * protected.
*/
static DEFINE_SPINLOCK(cgwb_lock);
-static DECLARE_WAIT_QUEUE_HEAD(cgwb_release_wait);
/**
* wb_congested_get_create - get or create a wb_congested
while (*node != NULL) {
parent = *node;
- congested = container_of(parent, struct bdi_writeback_congested,
- rb_node);
+ congested = rb_entry(parent, struct bdi_writeback_congested,
+ rb_node);
if (congested->blkcg_id < blkcg_id)
node = &parent->rb_left;
else if (congested->blkcg_id > blkcg_id)
return NULL;
atomic_set(&new_congested->refcnt, 0);
- new_congested->bdi = bdi;
+ new_congested->__bdi = bdi;
new_congested->blkcg_id = blkcg_id;
goto retry;
}
/* bdi might already have been destroyed leaving @congested unlinked */
- if (congested->bdi) {
+ if (congested->__bdi) {
rb_erase(&congested->rb_node,
- &congested->bdi->cgwb_congested_tree);
- congested->bdi = NULL;
+ &congested->__bdi->cgwb_congested_tree);
+ congested->__bdi = NULL;
}
spin_unlock_irqrestore(&cgwb_lock, flags);
{
struct bdi_writeback *wb = container_of(work, struct bdi_writeback,
release_work);
- struct backing_dev_info *bdi = wb->bdi;
-
- spin_lock_irq(&cgwb_lock);
- list_del_rcu(&wb->bdi_node);
- spin_unlock_irq(&cgwb_lock);
wb_shutdown(wb);
percpu_ref_exit(&wb->refcnt);
wb_exit(wb);
kfree_rcu(wb, rcu);
-
- if (atomic_dec_and_test(&bdi->usage_cnt))
- wake_up_all(&cgwb_release_wait);
}
static void cgwb_release(struct percpu_ref *refcnt)
percpu_ref_kill(&wb->refcnt);
}
+static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb)
+{
+ spin_lock_irq(&cgwb_lock);
+ list_del_rcu(&wb->bdi_node);
+ spin_unlock_irq(&cgwb_lock);
+}
+
static int cgwb_create(struct backing_dev_info *bdi,
struct cgroup_subsys_state *memcg_css, gfp_t gfp)
{
/* we might have raced another instance of this function */
ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb);
if (!ret) {
- atomic_inc(&bdi->usage_cnt);
list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list);
list_add(&wb->memcg_node, memcg_cgwb_list);
list_add(&wb->blkcg_node, blkcg_cgwb_list);
INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC);
bdi->cgwb_congested_tree = RB_ROOT;
- atomic_set(&bdi->usage_cnt, 1);
ret = wb_init(&bdi->wb, bdi, 1, GFP_KERNEL);
if (!ret) {
return ret;
}
-static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
+static void cgwb_bdi_unregister(struct backing_dev_info *bdi)
{
struct radix_tree_iter iter;
- struct rb_node *rbn;
void **slot;
+ struct bdi_writeback *wb;
WARN_ON(test_bit(WB_registered, &bdi->wb.state));
spin_lock_irq(&cgwb_lock);
-
radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0)
cgwb_kill(*slot);
- while ((rbn = rb_first(&bdi->cgwb_congested_tree))) {
- struct bdi_writeback_congested *congested =
- rb_entry(rbn, struct bdi_writeback_congested, rb_node);
-
- rb_erase(rbn, &bdi->cgwb_congested_tree);
- congested->bdi = NULL; /* mark @congested unlinked */
+ while (!list_empty(&bdi->wb_list)) {
+ wb = list_first_entry(&bdi->wb_list, struct bdi_writeback,
+ bdi_node);
+ spin_unlock_irq(&cgwb_lock);
+ wb_shutdown(wb);
+ spin_lock_irq(&cgwb_lock);
}
-
spin_unlock_irq(&cgwb_lock);
-
- /*
- * All cgwb's and their congested states must be shutdown and
- * released before returning. Drain the usage counter to wait for
- * all cgwb's and cgwb_congested's ever created on @bdi.
- */
- atomic_dec(&bdi->usage_cnt);
- wait_event(cgwb_release_wait, !atomic_read(&bdi->usage_cnt));
}
/**
spin_unlock_irq(&cgwb_lock);
}
+static void cgwb_bdi_exit(struct backing_dev_info *bdi)
+{
+ struct rb_node *rbn;
+
+ spin_lock_irq(&cgwb_lock);
+ while ((rbn = rb_first(&bdi->cgwb_congested_tree))) {
+ struct bdi_writeback_congested *congested =
+ rb_entry(rbn, struct bdi_writeback_congested, rb_node);
+
+ rb_erase(rbn, &bdi->cgwb_congested_tree);
+ congested->__bdi = NULL; /* mark @congested unlinked */
+ }
+ spin_unlock_irq(&cgwb_lock);
+}
+
+static void cgwb_bdi_register(struct backing_dev_info *bdi)
+{
+ spin_lock_irq(&cgwb_lock);
+ list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
+ spin_unlock_irq(&cgwb_lock);
+}
+
#else /* CONFIG_CGROUP_WRITEBACK */
static int cgwb_bdi_init(struct backing_dev_info *bdi)
return 0;
}
-static void cgwb_bdi_destroy(struct backing_dev_info *bdi)
+static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { }
+
+static void cgwb_bdi_exit(struct backing_dev_info *bdi)
{
wb_congested_put(bdi->wb_congested);
}
+static void cgwb_bdi_register(struct backing_dev_info *bdi)
+{
+ list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
+}
+
+static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb)
+{
+ list_del_rcu(&wb->bdi_node);
+}
+
#endif /* CONFIG_CGROUP_WRITEBACK */
-int bdi_init(struct backing_dev_info *bdi)
+static int bdi_init(struct backing_dev_info *bdi)
{
int ret;
ret = cgwb_bdi_init(bdi);
- list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list);
-
return ret;
}
-EXPORT_SYMBOL(bdi_init);
struct backing_dev_info *bdi_alloc_node(gfp_t gfp_mask, int node_id)
{
}
return bdi;
}
+EXPORT_SYMBOL(bdi_alloc_node);
-int bdi_register(struct backing_dev_info *bdi, struct device *parent,
- const char *fmt, ...)
+int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args)
{
- va_list args;
struct device *dev;
if (bdi->dev) /* The driver needs to use separate queues per device */
return 0;
- va_start(args, fmt);
- dev = device_create_vargs(bdi_class, parent, MKDEV(0, 0), bdi, fmt, args);
- va_end(args);
+ dev = device_create_vargs(bdi_class, NULL, MKDEV(0, 0), bdi, fmt, args);
if (IS_ERR(dev))
return PTR_ERR(dev);
+ cgwb_bdi_register(bdi);
bdi->dev = dev;
bdi_debug_register(bdi, dev_name(dev));
trace_writeback_bdi_register(bdi);
return 0;
}
-EXPORT_SYMBOL(bdi_register);
+EXPORT_SYMBOL(bdi_register_va);
-int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
+int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...)
{
- return bdi_register(bdi, NULL, "%u:%u", MAJOR(dev), MINOR(dev));
+ va_list args;
+ int ret;
+
+ va_start(args, fmt);
+ ret = bdi_register_va(bdi, fmt, args);
+ va_end(args);
+ return ret;
}
-EXPORT_SYMBOL(bdi_register_dev);
+EXPORT_SYMBOL(bdi_register);
int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner)
{
int rc;
- rc = bdi_register(bdi, NULL, "%u:%u", MAJOR(owner->devt),
- MINOR(owner->devt));
+ rc = bdi_register(bdi, "%u:%u", MAJOR(owner->devt), MINOR(owner->devt));
if (rc)
return rc;
+ /* Leaking owner reference... */
+ WARN_ON(bdi->owner);
bdi->owner = owner;
get_device(owner);
return 0;
/* make sure nobody finds us on the bdi_list anymore */
bdi_remove_from_list(bdi);
wb_shutdown(&bdi->wb);
- cgwb_bdi_destroy(bdi);
+ cgwb_bdi_unregister(bdi);
if (bdi->dev) {
bdi_debug_unregister(bdi);
}
}
-static void bdi_exit(struct backing_dev_info *bdi)
-{
- WARN_ON_ONCE(bdi->dev);
- wb_exit(&bdi->wb);
-}
-
static void release_bdi(struct kref *ref)
{
struct backing_dev_info *bdi =
container_of(ref, struct backing_dev_info, refcnt);
- bdi_exit(bdi);
+ if (test_bit(WB_registered, &bdi->wb.state))
+ bdi_unregister(bdi);
+ WARN_ON_ONCE(bdi->dev);
+ wb_exit(&bdi->wb);
+ cgwb_bdi_exit(bdi);
kfree(bdi);
}
{
kref_put(&bdi->refcnt, release_bdi);
}
-
-void bdi_destroy(struct backing_dev_info *bdi)
-{
- bdi_unregister(bdi);
- bdi_exit(bdi);
-}
-EXPORT_SYMBOL(bdi_destroy);
-
-/*
- * For use from filesystems to quickly init and register a bdi associated
- * with dirty writeback
- */
-int bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
-{
- int err;
-
- bdi->name = name;
- bdi->capabilities = 0;
- err = bdi_init(bdi);
- if (err)
- return err;
-
- err = bdi_register(bdi, NULL, "%.28s-%ld", name,
- atomic_long_inc_return(&bdi_seq));
- if (err) {
- bdi_destroy(bdi);
- return err;
- }
-
- return 0;
-}
-EXPORT_SYMBOL(bdi_setup_and_register);
+EXPORT_SYMBOL(bdi_put);
static wait_queue_head_t congestion_wqh[2] = {
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
projects / mirror_ubuntu-artful-kernel.git / blobdiff