diff --git a/fs/aio.c b/fs/aio.c index f8e52a1854c1..cabb5edd9bc1 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -77,6 +77,11 @@ struct kioctx_cpu { unsigned reqs_available; }; +struct ctx_rq_wait { + struct completion comp; + atomic_t count; +}; + struct kioctx { struct percpu_ref users; atomic_t dead; @@ -115,7 +120,7 @@ struct kioctx { /* * signals when all in-flight requests are done */ - struct completion *requests_done; + struct ctx_rq_wait *rq_wait; struct { /* @@ -535,8 +540,8 @@ static void free_ioctx_reqs(struct percpu_ref *ref) struct kioctx *ctx = container_of(ref, struct kioctx, reqs); /* At this point we know that there are no any in-flight requests */ - if (ctx->requests_done) - complete(ctx->requests_done); + if (ctx->rq_wait && atomic_dec_and_test(&ctx->rq_wait->count)) + complete(&ctx->rq_wait->comp); INIT_WORK(&ctx->free_work, free_ioctx); schedule_work(&ctx->free_work); @@ -744,7 +749,7 @@ err: * the rapid destruction of the kioctx. */ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx, - struct completion *requests_done) + struct ctx_rq_wait *wait) { struct kioctx_table *table; @@ -773,7 +778,7 @@ static int kill_ioctx(struct mm_struct *mm, struct kioctx *ctx, if (ctx->mmap_size) vm_munmap(ctx->mmap_base, ctx->mmap_size); - ctx->requests_done = requests_done; + ctx->rq_wait = wait; percpu_ref_kill(&ctx->users); return 0; } @@ -805,18 +810,24 @@ EXPORT_SYMBOL(wait_on_sync_kiocb); void exit_aio(struct mm_struct *mm) { struct kioctx_table *table = rcu_dereference_raw(mm->ioctx_table); - int i; + struct ctx_rq_wait wait; + int i, skipped; if (!table) return; + atomic_set(&wait.count, table->nr); + init_completion(&wait.comp); + + skipped = 0; for (i = 0; i < table->nr; ++i) { struct kioctx *ctx = table->table[i]; - struct completion requests_done = - COMPLETION_INITIALIZER_ONSTACK(requests_done); - if (!ctx) + if (!ctx) { + skipped++; continue; + } + /* * We don't need to bother with munmap() here - exit_mmap(mm) * is coming and it'll unmap everything. And we simply can't, @@ -825,10 +836,12 @@ void exit_aio(struct mm_struct *mm) * that it needs to unmap the area, just set it to 0. */ ctx->mmap_size = 0; - kill_ioctx(mm, ctx, &requests_done); + kill_ioctx(mm, ctx, &wait); + } + if (!atomic_sub_and_test(skipped, &wait.count)) { /* Wait until all IO for the context are done. */ - wait_for_completion(&requests_done); + wait_for_completion(&wait.comp); } RCU_INIT_POINTER(mm->ioctx_table, NULL); @@ -1313,15 +1326,17 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) { struct kioctx *ioctx = lookup_ioctx(ctx); if (likely(NULL != ioctx)) { - struct completion requests_done = - COMPLETION_INITIALIZER_ONSTACK(requests_done); + struct ctx_rq_wait wait; int ret; + init_completion(&wait.comp); + atomic_set(&wait.count, 1); + /* Pass requests_done to kill_ioctx() where it can be set * in a thread-safe way. If we try to set it here then we have * a race condition if two io_destroy() called simultaneously. */ - ret = kill_ioctx(current->mm, ioctx, &requests_done); + ret = kill_ioctx(current->mm, ioctx, &wait); percpu_ref_put(&ioctx->users); /* Wait until all IO for the context are done. Otherwise kernel @@ -1329,7 +1344,7 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) * is destroyed. */ if (!ret) - wait_for_completion(&requests_done); + wait_for_completion(&wait.comp); return ret; }