diff options
| -rw-r--r-- | fs/aio.c | 17 |
1 files changed, 17 insertions, 0 deletions
@@ -1642,6 +1642,23 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, goto out_put_req; spin_lock_irq(&ctx->ctx_lock); + /* + * We could have raced with io_destroy() and are currently holding a + * reference to ctx which should be destroyed. We cannot submit IO + * since ctx gets freed as soon as io_submit() puts its reference. The + * check here is reliable: io_destroy() sets ctx->dead before waiting + * for outstanding IO and the barrier between these two is realized by + * unlock of mm->ioctx_lock and lock of ctx->ctx_lock. Analogously we + * increment ctx->reqs_active before checking for ctx->dead and the + * barrier is realized by unlock and lock of ctx->ctx_lock. Thus if we + * don't see ctx->dead set here, io_destroy() waits for our IO to + * finish. + */ + if (ctx->dead) { + spin_unlock_irq(&ctx->ctx_lock); + ret = -EINVAL; + goto out_put_req; + } aio_run_iocb(req); if (!list_empty(&ctx->run_list)) { /* drain the run list */ |
