From patchwork Fri Aug 19 12:52:37 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Per Forlin X-Patchwork-Id: 1079492 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7JCuQCY005719 for ; Fri, 19 Aug 2011 12:56:26 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753253Ab1HSM4L (ORCPT ); Fri, 19 Aug 2011 08:56:11 -0400 Received: from eu1sys200aog108.obsmtp.com ([207.126.144.125]:47235 "EHLO eu1sys200aog108.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751421Ab1HSMzg (ORCPT ); Fri, 19 Aug 2011 08:55:36 -0400 Received: from beta.dmz-eu.st.com ([164.129.1.35]) (using TLSv1) by eu1sys200aob108.postini.com ([207.126.147.11]) with SMTP ID DSNKTk5dQw9/hzC8Y0VaYj2qV4SWffaL5POY@postini.com; Fri, 19 Aug 2011 12:55:36 UTC Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id ED3BE150; Fri, 19 Aug 2011 12:55:12 +0000 (GMT) Received: from relay1.stm.gmessaging.net (unknown [10.230.100.17]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 60B4D2145; Fri, 19 Aug 2011 12:55:12 +0000 (GMT) Received: from exdcvycastm004.EQ1STM.local (alteon-source-exch [10.230.100.61]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (Client CN "exdcvycastm004", Issuer "exdcvycastm004" (not verified)) by relay1.stm.gmessaging.net (Postfix) with ESMTPS id 41AB524C07C; Fri, 19 Aug 2011 14:55:05 +0200 (CEST) Received: from localhost.localdomain (10.230.100.153) by smtp.stericsson.com (10.230.100.2) with Microsoft SMTP Server (TLS) id 8.3.83.0; Fri, 19 Aug 2011 14:55:11 +0200 From: Per Forlin To: , , , Linus Walleij , Akinobu Mita Cc: Chris Ball , , Per Forlin Subject: [PATCH v9 2/3] mmc: core: add random fault injection Date: Fri, 19 Aug 2011 14:52:37 +0200 Message-ID: <1313758358-27536-3-git-send-email-per.forlin@stericsson.com> X-Mailer: git-send-email 1.6.3.3 In-Reply-To: <1313758358-27536-2-git-send-email-per.forlin@stericsson.com> References: <1313758358-27536-1-git-send-email-per.forlin@stericsson.com> <1313758358-27536-2-git-send-email-per.forlin@stericsson.com> MIME-Version: 1.0 Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Fri, 19 Aug 2011 12:56:26 +0000 (UTC) From: Per Forlin This adds support to inject data errors after a completed host transfer. The mmc core will return error even though the host transfer is successful. This simple fault injection proved to be very useful to test the non-blocking error handling in the mmc_blk_issue_rw_rq(). Random faults can also test how the host driver handles pre_req() and post_req() in case of errors. Signed-off-by: Per Forlin Acked-by: Akinobu Mita Reviewed-by: Linus Walleij --- drivers/mmc/core/core.c | 41 +++++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/debugfs.c | 25 +++++++++++++++++++++++++ include/linux/mmc/host.h | 5 +++++ lib/Kconfig.debug | 11 +++++++++++ 4 files changed, 82 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 91a0a74..d704dfa 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -24,6 +24,8 @@ #include #include #include +#include +#include #include #include @@ -83,6 +85,43 @@ static void mmc_flush_scheduled_work(void) flush_workqueue(workqueue); } +#ifdef CONFIG_FAIL_MMC_REQUEST + +/* + * Internal function. Inject random data errors. + * If mmc_data is NULL no errors are injected. + */ +static void mmc_should_fail_request(struct mmc_host *host, + struct mmc_request *mrq) +{ + struct mmc_command *cmd = mrq->cmd; + struct mmc_data *data = mrq->data; + static const int data_errors[] = { + -ETIMEDOUT, + -EILSEQ, + -EIO, + }; + + if (!data) + return; + + if (cmd->error || data->error || + !should_fail(&host->fail_mmc_request, data->blksz * data->blocks)) + return; + + data->error = data_errors[random32() % ARRAY_SIZE(data_errors)]; + data->bytes_xfered = (random32() % (data->bytes_xfered >> 9)) << 9; +} + +#else /* CONFIG_FAIL_MMC_REQUEST */ + +static inline void mmc_should_fail_request(struct mmc_host *host, + struct mmc_request *mrq) +{ +} + +#endif /* CONFIG_FAIL_MMC_REQUEST */ + /** * mmc_request_done - finish processing an MMC request * @host: MMC host which completed request @@ -109,6 +148,8 @@ void mmc_request_done(struct mmc_host *host, struct mmc_request *mrq) cmd->error = 0; host->ops->request(host, mrq); } else { + mmc_should_fail_request(host, mrq); + led_trigger_event(host->led, LED_OFF); pr_debug("%s: req done (CMD%u): %d: %08x %08x %08x %08x\n", diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c index 998797e..5acd707 100644 --- a/drivers/mmc/core/debugfs.c +++ b/drivers/mmc/core/debugfs.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -158,6 +159,23 @@ static int mmc_clock_opt_set(void *data, u64 val) return 0; } +#ifdef CONFIG_FAIL_MMC_REQUEST + +static DECLARE_FAULT_ATTR(fail_mmc_request); + +#ifdef KERNEL +/* + * Internal function. Pass the boot param fail_mmc_request to + * the setup fault injection attributes routine. + */ +static int __init setup_fail_mmc_request(char *str) +{ + return setup_fault_attr(&fail_mmc_request, str); +} +__setup("fail_mmc_request=", setup_fail_mmc_request); +#endif /* KERNEL */ +#endif /* CONFIG_FAIL_MMC_REQUEST */ + DEFINE_SIMPLE_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set, "%llu\n"); @@ -188,6 +206,13 @@ void mmc_add_host_debugfs(struct mmc_host *host) root, &host->clk_delay)) goto err_node; #endif +#ifdef CONFIG_FAIL_MMC_REQUEST + host->fail_mmc_request = fail_mmc_request; + if (IS_ERR(fault_create_debugfs_attr("fail_mmc_request", + root, + &host->fail_mmc_request))) + goto err_node; +#endif return; err_node: diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 1d09562..4c4bddf 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -12,6 +12,7 @@ #include #include +#include #include #include @@ -302,6 +303,10 @@ struct mmc_host { struct mmc_async_req *areq; /* active async req */ +#ifdef CONFIG_FAIL_MMC_REQUEST + struct fault_attr fail_mmc_request; +#endif + unsigned long private[0] ____cacheline_aligned; }; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c0cb9c4..1c7dbbf 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1070,6 +1070,17 @@ config FAIL_IO_TIMEOUT Only works with drivers that use the generic timeout handling, for others it wont do anything. +config FAIL_MMC_REQUEST + bool "Fault-injection capability for MMC IO" + select DEBUG_FS + depends on FAULT_INJECTION && MMC + help + Provide fault-injection capability for MMC IO. + This will make the mmc core return data errors. This is + useful to test the error handling in the mmc block device + and to test how the mmc host driver handles retries from + the block device. + config FAULT_INJECTION_DEBUG_FS bool "Debugfs entries for fault-injection capabilities" depends on FAULT_INJECTION && SYSFS && DEBUG_FS