From patchwork Tue Sep 22 10:13:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 258463 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=-6.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=no 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 7EF34C4727F for ; Tue, 22 Sep 2020 10:13:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28D52238D7 for ; Tue, 22 Sep 2020 10:13:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="XPRf7nmt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726613AbgIVKNz (ORCPT ); Tue, 22 Sep 2020 06:13:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:57238 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726424AbgIVKNy (ORCPT ); Tue, 22 Sep 2020 06:13:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1600769632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc; bh=hLNlwK4aAmxhaviZBEgCNkRcatYwoWqvV4tnyBUTyhM=; b=XPRf7nmtsmeOOSAfhiA8PUQkskgvCH4U88hWGCK3UFf3vOr74eOCXhLwwoK6C60kU7Lf7W b3q0CyVGknC6GF2YP13ijbx9gBPt+pqdN+RaCS3cTiZMQzcy3M++D15dJUCNXFsTgTd8Ky xn5+B8siVj+05y8Nsu+3A4n8k17Y+gM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E7D46ADAB; Tue, 22 Sep 2020 10:14:28 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Subject: [RFC] fixes for hangs and error reporting in CDC_WDM Date: Tue, 22 Sep 2020 12:13:23 +0200 Message-Id: <20200922101329.14801-1-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Stress testing has shown that CDC-WDM has some issues with hangs and error reporting 1. wakeups are not correctly handled in multhreaded environments 2. unresponsive hardware is not handled 3. errors are not correctly reported. This needs flush() to be implemented. For easier review all squashed together: --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -58,6 +58,9 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_MAX 16 +/* flush() is uninterruptible, but we cannot wait forever */ +#define WDM_FLUSH_TIMEOUT (30 * HZ) + /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ #define WDM_DEFAULT_BUFSIZE 256 @@ -151,7 +154,7 @@ static void wdm_out_callback(struct urb *urb) kfree(desc->outbuf); desc->outbuf = NULL; clear_bit(WDM_IN_USE, &desc->flags); - wake_up(&desc->wait); + wake_up_all(&desc->wait); } static void wdm_in_callback(struct urb *urb) @@ -393,6 +396,9 @@ static ssize_t wdm_write if (test_bit(WDM_RESETTING, &desc->flags)) r = -EIO; + if (test_bit(WDM_DISCONNECTING, &desc->flags)) + r = -ENODEV; + if (r < 0) { rv = r; goto out_free_mem_pm; @@ -424,6 +430,7 @@ static ssize_t wdm_write if (rv < 0) { desc->outbuf = NULL; clear_bit(WDM_IN_USE, &desc->flags); + wake_up_all(&desc->wait); /* for flush() */ dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv); rv = usb_translate_errors(rv); goto out_free_mem_pm; @@ -583,11 +590,39 @@ static ssize_t wdm_read return rv; } +/* + * The difference to flush is that we wait forever. If you don't like + * that behavior, you need to send a signal. + */ + +static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct wdm_device *desc = file->private_data; + int rv; + + rv = wait_event_interruptible(desc->wait, + !test_bit(WDM_IN_USE, &desc->flags) || + test_bit(WDM_DISCONNECTING, &desc->flags)); + + if (test_bit(WDM_DISCONNECTING, &desc->flags)) + return -ENODEV; + if (rv < 0) + return -EINTR; + + spin_lock_irq(&desc->iuspin); + rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); + + return usb_translate_errors(rv); +} + static int wdm_flush(struct file *file, fl_owner_t id) { struct wdm_device *desc = file->private_data; + int rv; - wait_event(desc->wait, + rv = wait_event_timeout(desc->wait, /* * needs both flags. We cannot do with one * because resetting it would cause a race @@ -595,16 +630,25 @@ static int wdm_flush(struct file *file, fl_owner_t id) * a disconnect */ !test_bit(WDM_IN_USE, &desc->flags) || - test_bit(WDM_DISCONNECTING, &desc->flags)); + test_bit(WDM_DISCONNECTING, &desc->flags), + WDM_FLUSH_TIMEOUT); - /* cannot dereference desc->intf if WDM_DISCONNECTING */ + /* + * to report the correct error. + * This is best effort + * We are inevitably racing with the hardware. + */ if (test_bit(WDM_DISCONNECTING, &desc->flags)) return -ENODEV; - if (desc->werr < 0) - dev_err(&desc->intf->dev, "Error in flush path: %d\n", - desc->werr); + if (!rv) + return -EIO; + + spin_lock_irq(&desc->iuspin); + rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); - return usb_translate_errors(desc->werr); + return usb_translate_errors(rv); } static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait) @@ -729,6 +773,7 @@ static const struct file_operations wdm_fops = { .owner = THIS_MODULE, .read = wdm_read, .write = wdm_write, + .fsync = wdm_fsync, .open = wdm_open, .flush = wdm_flush, From patchwork Tue Sep 22 10:13:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 258465 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 2EC7AC4727E for ; Tue, 22 Sep 2020 10:13:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2B00238D7 for ; Tue, 22 Sep 2020 10:13:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="ClIR5y/A" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726610AbgIVKNz (ORCPT ); Tue, 22 Sep 2020 06:13:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:57288 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726603AbgIVKNy (ORCPT ); Tue, 22 Sep 2020 06:13:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1600769632; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=A1zUt81juSwPNJhRNl1BNHYKJV8/bvmy1vlgpsFmi6U=; b=ClIR5y/AzkBBrptKFa/nsVH3qtXs6ZN8ruJYF41+FxNTnVbY40YZQPtyvUmjjsSjIFlKI6 D9TgVVs5UqosWZDrccx3HLiYZSrKV/3kPHYVzaxeuTD+g0DoCFRkHgDE7cKpuux6JZkTo0 fB8CCwRY+ZzP7uLNmkrSnQpVhr/tsFU= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 80328B03D; Tue, 22 Sep 2020 10:14:29 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 2/6] CDC-WDM: introduce a timeout in flush() Date: Tue, 22 Sep 2020 12:13:25 +0200 Message-Id: <20200922101329.14801-3-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922101329.14801-1-oneukum@suse.com> References: <20200922101329.14801-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Malicious or defective hardware may cease communication while flush() is running. In last consequence we need a timeout, as hardware that remains silent must be ignored. Making the wait for IO interruptible would not solve the issue. While it would avoid a hang, it would not allow any progress and we would end up with an unclosable fd. The 30 seconds are coming out of thin air. Reported-by: Tetsuo Handa Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index adb3fc307083..b3a3f249a915 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -58,6 +58,9 @@ MODULE_DEVICE_TABLE (usb, wdm_ids); #define WDM_MAX 16 +/* flush() is uninterruptible, but we cannot wait forever */ +#define WDM_FLUSH_TIMEOUT (30 * HZ) + /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */ #define WDM_DEFAULT_BUFSIZE 256 @@ -589,7 +592,7 @@ static int wdm_flush(struct file *file, fl_owner_t id) struct wdm_device *desc = file->private_data; int rv; - wait_event(desc->wait, + rv = wait_event_timeout(desc->wait, /* * needs both flags. We cannot do with one * because resetting it would cause a race @@ -597,11 +600,15 @@ static int wdm_flush(struct file *file, fl_owner_t id) * a disconnect */ !test_bit(WDM_IN_USE, &desc->flags) || - test_bit(WDM_DISCONNECTING, &desc->flags)); + test_bit(WDM_DISCONNECTING, &desc->flags), + WDM_FLUSH_TIMEOUT); /* cannot dereference desc->intf if WDM_DISCONNECTING */ if (test_bit(WDM_DISCONNECTING, &desc->flags)) return -ENODEV; + if (!rv) + return -EIO; + rv = desc->werr; if (rv < 0) dev_err(&desc->intf->dev, "Error in flush path: %d\n", From patchwork Tue Sep 22 10:13:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 297554 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 8D533C2D0E2 for ; Tue, 22 Sep 2020 10:13:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40C752395B for ; Tue, 22 Sep 2020 10:13:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="m/ttvBtC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726607AbgIVKNy (ORCPT ); Tue, 22 Sep 2020 06:13:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:57334 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726604AbgIVKNy (ORCPT ); Tue, 22 Sep 2020 06:13:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1600769633; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=RxFQPXtnIY8PwL4wcaQVQPCXz6qQ+yIZN0Kpgnlyksg=; b=m/ttvBtCfIEOJJJwtIHFToehD7wQ20YaUX4a8XvM+B5UpiIzar//Vl6dIh0eV5loFVPPtI q+NJzZjvdj153zK2nAZ5IepWat1iojtBzElToDtRusz0501scdqKKrPnjwuR5uXBAip0gi R8gqZvNWUuKOGdImyB/3IUsuZrtFrm0= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C748BB213; Tue, 22 Sep 2020 10:14:29 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 3/6] CDC-WDM: remove use of intf->dev after potential disconnect Date: Tue, 22 Sep 2020 12:13:26 +0200 Message-Id: <20200922101329.14801-4-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922101329.14801-1-oneukum@suse.com> References: <20200922101329.14801-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org After a disconnect intf->dev is not a valid pointer any longer. As flush() uses it only for logging purposes logging is not worth it. Remove the dev_err() Reported-by: Tetsuo Handa Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index b3a3f249a915..1ca2c85a977d 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -603,16 +603,17 @@ static int wdm_flush(struct file *file, fl_owner_t id) test_bit(WDM_DISCONNECTING, &desc->flags), WDM_FLUSH_TIMEOUT); - /* cannot dereference desc->intf if WDM_DISCONNECTING */ + /* + * to report the correct error. + * This is best effort + * We are inevitably racing with the hardware. + */ if (test_bit(WDM_DISCONNECTING, &desc->flags)) return -ENODEV; if (!rv) return -EIO; rv = desc->werr; - if (rv < 0) - dev_err(&desc->intf->dev, "Error in flush path: %d\n", - rv); return usb_translate_errors(rv); } From patchwork Tue Sep 22 10:13:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 297553 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 A8850C2D0E2 for ; Tue, 22 Sep 2020 10:13:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56E3A2395B for ; Tue, 22 Sep 2020 10:13:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="It8rTNJz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726509AbgIVKNz (ORCPT ); Tue, 22 Sep 2020 06:13:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:57352 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726605AbgIVKNy (ORCPT ); Tue, 22 Sep 2020 06:13:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1600769633; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=3J4awFmP6XNuAxKP8nvMUO9NLGMgKpv8n8B5oWGFW6o=; b=It8rTNJzce86wU+tUp1PnTI34w/VBTqETGCQ5NlyRgXO+iJ19TJ70cVcrcgPpGp3HiOgyv b1rtjSZ3TRFCn/huAi2WD3WUwhgQlAXMogv27Gy7hO9i34oROqFYAfwiWQ25LobEzyvWtE uXVOsZgtZiPBNklTTkSd0uNHDLIDYgM= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 1BDF0ABD2; Tue, 22 Sep 2020 10:14:30 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 4/6] CDC-WDM: fix race reporting errors in flush Date: Tue, 22 Sep 2020 12:13:27 +0200 Message-Id: <20200922101329.14801-5-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922101329.14801-1-oneukum@suse.com> References: <20200922101329.14801-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In case a race was lost and multiple fds used, an error could be reported multiple times. To fix this a spinlock must be taken. Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 1ca2c85a977d..5fb855404403 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -613,7 +613,10 @@ static int wdm_flush(struct file *file, fl_owner_t id) if (!rv) return -EIO; + spin_lock_irq(&desc->iuspin); rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); return usb_translate_errors(rv); } From patchwork Tue Sep 22 10:13:28 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 297552 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 4246DC4741F for ; Tue, 22 Sep 2020 10:13:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAD7A2395B for ; Tue, 22 Sep 2020 10:13:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="kjG0aSqX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726461AbgIVKN5 (ORCPT ); Tue, 22 Sep 2020 06:13:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:57420 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726609AbgIVKNz (ORCPT ); Tue, 22 Sep 2020 06:13:55 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1600769633; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=enkvzSACilXPdBEKnE+T7BwCxIvLK9Ib/5smmf0iTFA=; b=kjG0aSqXh3sVlnYVFb7chij5FgUp8MxK8Qfsftj3ObS92JGytJGyYuhOuDdBNaX4nhLT1h ZwE87Nbm167CgBw9qhFZYYblaSBKZDDd5SKQa3xBHbRFHsXAlCGNsWJukkKzJeK0iQKz5G bj63IhycLk9FdpDcEmDDzJgmxKpAxs8= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 64191B215; Tue, 22 Sep 2020 10:14:30 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 5/6] CDC-WDM: correct error reporting in write() Date: Tue, 22 Sep 2020 12:13:28 +0200 Message-Id: <20200922101329.14801-6-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922101329.14801-1-oneukum@suse.com> References: <20200922101329.14801-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In case our wait was interrupted by a disconnect, we should report that. Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 5fb855404403..242f83118208 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -396,6 +396,9 @@ static ssize_t wdm_write if (test_bit(WDM_RESETTING, &desc->flags)) r = -EIO; + if (test_bit(WDM_DISCONNECTING, &desc->flags)) + r = -ENODEV; + if (r < 0) { rv = r; goto out_free_mem_pm; From patchwork Tue Sep 22 10:13:29 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oliver Neukum X-Patchwork-Id: 297551 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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 724CAC2D0E2 for ; Tue, 22 Sep 2020 10:14:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B52F239A1 for ; Tue, 22 Sep 2020 10:14:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=suse.com header.i=@suse.com header.b="BbKT2oAC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726617AbgIVKN6 (ORCPT ); Tue, 22 Sep 2020 06:13:58 -0400 Received: from mx2.suse.de ([195.135.220.15]:57422 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726604AbgIVKNz (ORCPT ); Tue, 22 Sep 2020 06:13:55 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1600769634; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:in-reply-to:in-reply-to:references:references; bh=IRlIWc5ddJjwc1HhS2ARyazLOr5MJTHSYzCeSf9kUQU=; b=BbKT2oAC6RvZNYxT5mDZK+I2Q+SKnEYByF9E4nkQUJIG10mZ8ZtUPJq8TQ0r1O7sP00WTp Uz7sSyvWyr8L0t1mktrhe3b7+EHRNwFnzbKyfgWAgJoSO6wAZXglKZTRcc1M8Lb0ugd/jZ 3W8gYtgwbu2qdM94h9gmSxv2Aynh8C4= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id AC59BB18C; Tue, 22 Sep 2020 10:14:30 +0000 (UTC) From: Oliver Neukum To: penguin-kernel@i-love.sakura.ne.jp, bjorn@mork.no, linux-usb@vger.kernel.org Cc: Oliver Neukum Subject: [RFC 6/6] CDC-WDM: implement fsync Date: Tue, 22 Sep 2020 12:13:29 +0200 Message-Id: <20200922101329.14801-7-oneukum@suse.com> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200922101329.14801-1-oneukum@suse.com> References: <20200922101329.14801-1-oneukum@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org Some users want to be very sure that data has gone out to the device. This needs fsync. Reported-by: Tetsuo Handa Signed-off-by: Oliver Neukum --- drivers/usb/class/cdc-wdm.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 242f83118208..6ea03c12380c 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -590,6 +590,33 @@ static ssize_t wdm_read return rv; } +/* + * The difference to flush is that we wait forever. If you don't like + * that behavior, you need to send a signal. + */ + +static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync) +{ + struct wdm_device *desc = file->private_data; + int rv; + + rv = wait_event_interruptible(desc->wait, + !test_bit(WDM_IN_USE, &desc->flags) || + test_bit(WDM_DISCONNECTING, &desc->flags)); + + if (test_bit(WDM_DISCONNECTING, &desc->flags)) + return -ENODEV; + if (rv < 0) + return -EINTR; + + spin_lock_irq(&desc->iuspin); + rv = desc->werr; + desc->werr = 0; + spin_unlock_irq(&desc->iuspin); + + return usb_translate_errors(rv); +} + static int wdm_flush(struct file *file, fl_owner_t id) { struct wdm_device *desc = file->private_data; @@ -746,6 +773,7 @@ static const struct file_operations wdm_fops = { .owner = THIS_MODULE, .read = wdm_read, .write = wdm_write, + .fsync = wdm_fsync, .open = wdm_open, .flush = wdm_flush, .release = wdm_release,