From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42DA3C3F2D1 for ; Tue, 3 Mar 2020 18:09:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 191B4208C3 for ; Tue, 3 Mar 2020 18:09:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583258971; bh=242ju/f1UL0RmgOXdz4af0lNK8ENlCQQx6rAW3hkU6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aBw9C1TtlcxTjnyyS3BiPBLF+yNKGghGXz7KOXEyjnNilIQ38msYQ2fcfgtBR10vQ l0eM3jpWEHqslhG30Zzazuw8dYT3oDXLeG7BjdKl8shAeofNuFeAlkopXIGnSVkrE6 9f14+CWThdPVqnymTMEVBtJCjhzMvwSY0jicHPgk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732132AbgCCRwT (ORCPT ); Tue, 3 Mar 2020 12:52:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:60596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731876AbgCCRwP (ORCPT ); Tue, 3 Mar 2020 12:52:15 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id ADD9D2146E; Tue, 3 Mar 2020 17:52:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257935; bh=242ju/f1UL0RmgOXdz4af0lNK8ENlCQQx6rAW3hkU6s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GN3byUCTlLsELEx6H2hmA73HRYTHBZcNdnk8ktlPDqRapVagXwynzFSNfkFhyXZZm sLf3tgMlWYHy/U9gOYhfGMDuKrPxdwYNQiYhZtIptW1CsJanlVrOcvq3be4He4a1pi wFtLm16XonqDNEQoNricspapdRmIX1lqp8MEdB4Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe , Sasha Levin Subject: [PATCH 5.4 001/152] io_uring: grab ->fs as part of async offload Date: Tue, 3 Mar 2020 18:41:39 +0100 Message-Id: <20200303174302.711223909@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174302.523080016@linuxfoundation.org> References: <20200303174302.523080016@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jens Axboe [ Upstream commits 9392a27d88b9 and ff002b30181d ] Ensure that the async work grabs ->fs from the queueing task if the punted commands needs to do lookups. We don't have these two commits in 5.4-stable: ff002b30181d30cdfbca316dadd099c3ca0d739c 9392a27d88b9707145d713654eb26f0c29789e50 because they don't apply with the rework that was done in how io_uring handles offload. Since there's no io-wq in 5.4, it doesn't make sense to do two patches. I'm attaching my port of the two for 5.4-stable, it's been tested. Please queue it up for the next 5.4-stable, thanks! Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- fs/io_uring.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index ed9a551882cf3..f34a8f7eee5d1 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -71,6 +71,7 @@ #include #include #include +#include #include @@ -334,6 +335,8 @@ struct io_kiocb { u32 result; u32 sequence; + struct fs_struct *fs; + struct work_struct work; }; @@ -651,6 +654,7 @@ static struct io_kiocb *io_get_req(struct io_ring_ctx *ctx, /* one is dropped after submission, the other at completion */ refcount_set(&req->refs, 2); req->result = 0; + req->fs = NULL; return req; out: percpu_ref_put(&ctx->refs); @@ -1663,6 +1667,16 @@ static int io_send_recvmsg(struct io_kiocb *req, const struct io_uring_sqe *sqe, ret = -EINTR; } + if (req->fs) { + struct fs_struct *fs = req->fs; + + spin_lock(&req->fs->lock); + if (--fs->users) + fs = NULL; + spin_unlock(&req->fs->lock); + if (fs) + free_fs_struct(fs); + } io_cqring_add_event(req->ctx, sqe->user_data, ret); io_put_req(req); return 0; @@ -2159,6 +2173,7 @@ static inline bool io_sqe_needs_user(const struct io_uring_sqe *sqe) static void io_sq_wq_submit_work(struct work_struct *work) { struct io_kiocb *req = container_of(work, struct io_kiocb, work); + struct fs_struct *old_fs_struct = current->fs; struct io_ring_ctx *ctx = req->ctx; struct mm_struct *cur_mm = NULL; struct async_list *async_list; @@ -2178,6 +2193,15 @@ restart: /* Ensure we clear previously set non-block flag */ req->rw.ki_flags &= ~IOCB_NOWAIT; + if (req->fs != current->fs && current->fs != old_fs_struct) { + task_lock(current); + if (req->fs) + current->fs = req->fs; + else + current->fs = old_fs_struct; + task_unlock(current); + } + ret = 0; if (io_sqe_needs_user(sqe) && !cur_mm) { if (!mmget_not_zero(ctx->sqo_mm)) { @@ -2276,6 +2300,11 @@ out: mmput(cur_mm); } revert_creds(old_cred); + if (old_fs_struct) { + task_lock(current); + current->fs = old_fs_struct; + task_unlock(current); + } } /* @@ -2503,6 +2532,23 @@ err: req->user_data = s->sqe->user_data; +#if defined(CONFIG_NET) + switch (READ_ONCE(s->sqe->opcode)) { + case IORING_OP_SENDMSG: + case IORING_OP_RECVMSG: + spin_lock(¤t->fs->lock); + if (!current->fs->in_exec) { + req->fs = current->fs; + req->fs->users++; + } + spin_unlock(¤t->fs->lock); + if (!req->fs) { + ret = -EAGAIN; + goto err_req; + } + } +#endif + /* * If we already have a head request, queue this one for async * submittal once the head completes. If we don't have a head but -- 2.20.1