diff --git a/drivers/target/target_core_tpg.c b/drivers/target/target_core_tpg.c index c036595b17cfc9cfc75f9bd57d146bfb4179d67b..fddfae61222f2e3bf3a063d6ab11d6438e4ff897 100644 --- a/drivers/target/target_core_tpg.c +++ b/drivers/target/target_core_tpg.c @@ -825,7 +825,7 @@ int core_tpg_add_lun( ret = core_dev_export(dev, tpg, lun); if (ret < 0) { - percpu_ref_cancel_init(&lun->lun_ref); + percpu_ref_exit(&lun->lun_ref); return ret; } @@ -880,5 +880,7 @@ int core_tpg_post_dellun( lun->lun_status = TRANSPORT_LUN_STATUS_FREE; spin_unlock(&tpg->tpg_lun_lock); + percpu_ref_exit(&lun->lun_ref); + return 0; } diff --git a/fs/aio.c b/fs/aio.c index 5e0d7f9cb693480f5e214c567585aaa5bdf32792..ea1bc2e8f4f30c2c05d1fd597e0c32cb80bd0c41 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -506,6 +506,8 @@ static void free_ioctx(struct work_struct *work) aio_free_ring(ctx); free_percpu(ctx->cpu); + percpu_ref_exit(&ctx->reqs); + percpu_ref_exit(&ctx->users); kmem_cache_free(kioctx_cachep, ctx); } @@ -715,8 +717,8 @@ static struct kioctx *ioctx_alloc(unsigned nr_events) err: mutex_unlock(&ctx->ring_lock); free_percpu(ctx->cpu); - percpu_ref_cancel_init(&ctx->reqs); - percpu_ref_cancel_init(&ctx->users); + percpu_ref_exit(&ctx->reqs); + percpu_ref_exit(&ctx->users); kmem_cache_free(kioctx_cachep, ctx); pr_debug("error allocating ioctx %d\n", err); return ERR_PTR(err); diff --git a/include/linux/percpu-refcount.h b/include/linux/percpu-refcount.h index 6f8cd4c0546cb63ca18447962cd6cbf787adb8f6..0ddd2839ca846a63ba7f835a05d8d4bfa60e6c54 100644 --- a/include/linux/percpu-refcount.h +++ b/include/linux/percpu-refcount.h @@ -57,9 +57,7 @@ struct percpu_ref { atomic_t count; /* * The low bit of the pointer indicates whether the ref is in percpu - * mode; if set, then get/put will manipulate the atomic_t (this is a - * hack because we need to keep the pointer around for - * percpu_ref_kill_rcu()) + * mode; if set, then get/put will manipulate the atomic_t. */ unsigned long pcpu_count_ptr; percpu_ref_func_t *release; @@ -69,7 +67,7 @@ struct percpu_ref { int __must_check percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release); -void percpu_ref_cancel_init(struct percpu_ref *ref); +void percpu_ref_exit(struct percpu_ref *ref); void percpu_ref_kill_and_confirm(struct percpu_ref *ref, percpu_ref_func_t *confirm_kill); diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 7868fc3c0bc59b3223490114ca8e27f83b4c864c..c06aa5e257a89ab3e1e9bbf777713636bf222661 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1638,7 +1638,7 @@ static int cgroup_setup_root(struct cgroup_root *root, unsigned int ss_mask) exit_root_id: cgroup_exit_root_id(root); cancel_ref: - percpu_ref_cancel_init(&root_cgrp->self.refcnt); + percpu_ref_exit(&root_cgrp->self.refcnt); out: free_cgrp_cset_links(&tmp_links); return ret; @@ -4133,6 +4133,8 @@ static void css_free_work_fn(struct work_struct *work) container_of(work, struct cgroup_subsys_state, destroy_work); struct cgroup *cgrp = css->cgroup; + percpu_ref_exit(&css->refcnt); + if (css->ss) { /* css free path */ if (css->parent) @@ -4330,7 +4332,7 @@ static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss) err_free_id: cgroup_idr_remove(&ss->css_idr, css->id); err_free_percpu_ref: - percpu_ref_cancel_init(&css->refcnt); + percpu_ref_exit(&css->refcnt); err_free_css: call_rcu(&css->rcu_head, css_free_rcu_fn); return err; @@ -4441,7 +4443,7 @@ static int cgroup_mkdir(struct kernfs_node *parent_kn, const char *name, out_free_id: cgroup_idr_remove(&root->cgroup_idr, cgrp->id); out_cancel_ref: - percpu_ref_cancel_init(&cgrp->self.refcnt); + percpu_ref_exit(&cgrp->self.refcnt); out_free_cgrp: kfree(cgrp); out_unlock: diff --git a/lib/percpu-refcount.c b/lib/percpu-refcount.c index 94e5b624de640612a639a12c5fdfe092f77b1270..ac4299120087e3ff25c9cc707f4c175dccfb2da5 100644 --- a/lib/percpu-refcount.c +++ b/lib/percpu-refcount.c @@ -61,36 +61,25 @@ int percpu_ref_init(struct percpu_ref *ref, percpu_ref_func_t *release) EXPORT_SYMBOL_GPL(percpu_ref_init); /** - * percpu_ref_cancel_init - cancel percpu_ref_init() - * @ref: percpu_ref to cancel init for + * percpu_ref_exit - undo percpu_ref_init() + * @ref: percpu_ref to exit * - * Once a percpu_ref is initialized, its destruction is initiated by - * percpu_ref_kill() and completes asynchronously, which can be painful to - * do when destroying a half-constructed object in init failure path. - * - * This function destroys @ref without invoking @ref->release and the - * memory area containing it can be freed immediately on return. To - * prevent accidental misuse, it's required that @ref has finished - * percpu_ref_init(), whether successful or not, but never used. - * - * The weird name and usage restriction are to prevent people from using - * this function by mistake for normal shutdown instead of - * percpu_ref_kill(). + * This function exits @ref. The caller is responsible for ensuring that + * @ref is no longer in active use. The usual places to invoke this + * function from are the @ref->release() callback or in init failure path + * where percpu_ref_init() succeeded but other parts of the initialization + * of the embedding object failed. */ -void percpu_ref_cancel_init(struct percpu_ref *ref) +void percpu_ref_exit(struct percpu_ref *ref) { unsigned __percpu *pcpu_count = pcpu_count_ptr(ref); - int cpu; - - WARN_ON_ONCE(atomic_read(&ref->count) != 1 + PCPU_COUNT_BIAS); if (pcpu_count) { - for_each_possible_cpu(cpu) - WARN_ON_ONCE(*per_cpu_ptr(pcpu_count, cpu)); free_percpu(pcpu_count); + ref->pcpu_count_ptr = PCPU_REF_DEAD; } } -EXPORT_SYMBOL_GPL(percpu_ref_cancel_init); +EXPORT_SYMBOL_GPL(percpu_ref_exit); static void percpu_ref_kill_rcu(struct rcu_head *rcu) { @@ -102,8 +91,6 @@ static void percpu_ref_kill_rcu(struct rcu_head *rcu) for_each_possible_cpu(cpu) count += *per_cpu_ptr(pcpu_count, cpu); - free_percpu(pcpu_count); - pr_debug("global %i pcpu %i", atomic_read(&ref->count), (int) count); /*