From patchwork Tue Aug 9 11:48:58 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Per Forlin X-Patchwork-Id: 3311 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 5D34023F3F for ; Tue, 9 Aug 2011 11:49:32 +0000 (UTC) Received: from mail-qy0-f180.google.com (mail-qy0-f180.google.com [209.85.216.180]) by fiordland.canonical.com (Postfix) with ESMTP id 0F69BA18099 for ; Tue, 9 Aug 2011 11:49:31 +0000 (UTC) Received: by qyk31 with SMTP id 31so3282088qyk.11 for ; Tue, 09 Aug 2011 04:49:31 -0700 (PDT) Received: by 10.229.44.195 with SMTP id b3mr5286900qcf.7.1312890569995; Tue, 09 Aug 2011 04:49:29 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.229.190.71 with SMTP id dh7cs44219qcb; Tue, 9 Aug 2011 04:49:29 -0700 (PDT) Received: from mr.google.com ([10.213.17.3]) by 10.213.17.3 with SMTP id q3mr943770eba.18.1312890569370 (num_hops = 1); Tue, 09 Aug 2011 04:49:29 -0700 (PDT) Received: by 10.213.17.3 with SMTP id q3mr689870eba.18.1312890568746; Tue, 09 Aug 2011 04:49:28 -0700 (PDT) Received: from mail-ew0-f50.google.com (mail-ew0-f50.google.com [209.85.215.50]) by mx.google.com with ESMTPS id e19si1968605eeb.2.2011.08.09.04.49.28 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 09 Aug 2011 04:49:28 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.215.50 is neither permitted nor denied by best guess record for domain of per.forlin@linaro.org) client-ip=209.85.215.50; Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.215.50 is neither permitted nor denied by best guess record for domain of per.forlin@linaro.org) smtp.mail=per.forlin@linaro.org Received: by mail-ew0-f50.google.com with SMTP id 10so1627696ewy.37 for ; Tue, 09 Aug 2011 04:49:28 -0700 (PDT) Received: by 10.213.14.16 with SMTP id e16mr1916901eba.47.1312890567830; Tue, 09 Aug 2011 04:49:27 -0700 (PDT) Received: from localhost.localdomain (c-c37f71d5.029-82-6c756e10.cust.bredbandsbolaget.se [213.113.127.195]) by mx.google.com with ESMTPS id v20sm2991237eeh.46.2011.08.09.04.49.26 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 09 Aug 2011 04:49:27 -0700 (PDT) From: Per Forlin To: Akinobu Mita , akpm@linux-foundation.org, Linus Walleij , linux-kernel@vger.kernel.org, Randy Dunlap , Chris Ball Cc: linux-doc@vger.kernel.org, linux-mmc@vger.kernel.org, linaro-dev@lists.linaro.org, linux-mm@kvack.org, Per Forlin Subject: [PATCH --mmotm v7 2/3] mmc: core: add random fault injection Date: Tue, 9 Aug 2011 13:48:58 +0200 Message-Id: <1312890539-28177-3-git-send-email-per.forlin@linaro.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1312890539-28177-1-git-send-email-per.forlin@linaro.org> References: <1312890539-28177-1-git-send-email-per.forlin@linaro.org> 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 --- drivers/mmc/core/core.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/debugfs.c | 27 +++++++++++++++++++++++++++ include/linux/mmc/host.h | 7 +++++++ lib/Kconfig.debug | 11 +++++++++++ 4 files changed, 89 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 89bdeae..a4996b0 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -25,6 +25,11 @@ #include #include +#ifdef CONFIG_FAIL_MMC_REQUEST +#include +#include +#endif + #include #include #include @@ -83,6 +88,43 @@ 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 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 +151,8 @@ 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 f573753..189581d 100644 --- a/drivers/mmc/core/debugfs.c +++ b/drivers/mmc/core/debugfs.c @@ -13,6 +13,9 @@ #include #include #include +#ifdef CONFIG_FAIL_MMC_REQUEST +#include +#endif #include #include @@ -159,6 +162,23 @@ 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"); @@ -189,6 +209,13 @@ 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 0f83858..ee472fe 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -12,6 +12,9 @@ #include #include +#ifdef CONFIG_FAIL_MMC_REQUEST +#include +#endif #include #include @@ -304,6 +307,10 @@ 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 47879c7..ebff0c9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1090,6 +1090,17 @@ 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