From patchwork Tue Jun 21 23:38:40 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Per Forlin X-Patchwork-Id: 2145 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 B435923F3F for ; Tue, 21 Jun 2011 23:40:12 +0000 (UTC) Received: from mail-vw0-f52.google.com (mail-vw0-f52.google.com [209.85.212.52]) by fiordland.canonical.com (Postfix) with ESMTP id 8341FA188A0 for ; Tue, 21 Jun 2011 23:40:12 +0000 (UTC) Received: by mail-vw0-f52.google.com with SMTP id 16so361694vws.11 for ; Tue, 21 Jun 2011 16:40:12 -0700 (PDT) Received: by 10.52.168.65 with SMTP id zu1mr5764773vdb.207.1308699612287; Tue, 21 Jun 2011 16:40:12 -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 10.52.183.130 with SMTP id em2cs104811vdc; Tue, 21 Jun 2011 16:40:12 -0700 (PDT) Received: by 10.204.85.79 with SMTP id n15mr16812bkl.38.1308699611625; Tue, 21 Jun 2011 16:40:11 -0700 (PDT) Received: from mail-bw0-f50.google.com (mail-bw0-f50.google.com [209.85.214.50]) by mx.google.com with ESMTPS id e4si8544892bkt.31.2011.06.21.16.40.10 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 21 Jun 2011 16:40:11 -0700 (PDT) Received-SPF: neutral (google.com: 209.85.214.50 is neither permitted nor denied by best guess record for domain of per.forlin@linaro.org) client-ip=209.85.214.50; Authentication-Results: mx.google.com; spf=neutral (google.com: 209.85.214.50 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-bw0-f50.google.com with SMTP id 2so484016bwz.37 for ; Tue, 21 Jun 2011 16:40:10 -0700 (PDT) Received: by 10.204.48.210 with SMTP id s18mr342513bkf.176.1308699610201; Tue, 21 Jun 2011 16:40:10 -0700 (PDT) Received: from localhost.localdomain (c-3c7b71d5.029-82-6c756e10.cust.bredbandsbolaget.se [213.113.123.60]) by mx.google.com with ESMTPS id g13sm3910735bkd.10.2011.06.21.16.40.08 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 21 Jun 2011 16:40:09 -0700 (PDT) From: Per Forlin To: linaro-dev@lists.linaro.org, Nicolas Pitre , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, Venkatraman S Cc: Chris Ball , Per Forlin Subject: [PATCH v7 10/11] mmc: test: add random fault injection in core.c Date: Wed, 22 Jun 2011 01:38:40 +0200 Message-Id: <1308699521-20556-11-git-send-email-per.forlin@linaro.org> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1308699521-20556-1-git-send-email-per.forlin@linaro.org> References: <1308699521-20556-1-git-send-email-per.forlin@linaro.org> This simple fault injection proved to be very useful to test the error handling in the block.c rw_rq(). It may still be useful to test if the host driver handle pre_req() and post_req() correctly in case of errors. Signed-off-by: Per Forlin --- drivers/mmc/core/core.c | 54 ++++++++++++++++++++++++++++++++++++++++++++ drivers/mmc/core/debugfs.c | 5 ++++ include/linux/mmc/host.h | 3 ++ lib/Kconfig.debug | 11 +++++++++ 4 files changed, 73 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index c82fa3b..481c557 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -23,6 +23,8 @@ #include #include #include +#include +#include #include #include @@ -82,6 +84,56 @@ static void mmc_flush_scheduled_work(void) flush_workqueue(workqueue); } +#ifdef CONFIG_FAIL_MMC_REQUEST + +static DECLARE_FAULT_ATTR(fail_mmc_request); + +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); + +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 || !host->make_it_fail || + !should_fail(&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; +} + +static int __init fail_mmc_request_debugfs(void) +{ + return init_fault_attr_dentries(&fail_mmc_request, + "fail_mmc_request"); +} + +late_initcall(fail_mmc_request_debugfs); + +#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 @@ -108,6 +160,8 @@ 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..588e76f 100644 --- a/drivers/mmc/core/debugfs.c +++ b/drivers/mmc/core/debugfs.c @@ -188,6 +188,11 @@ void mmc_add_host_debugfs(struct mmc_host *host) root, &host->clk_delay)) goto err_node; #endif +#ifdef CONFIG_FAIL_MMC_REQUEST + if (!debugfs_create_u8("make-it-fail", S_IRUSR | S_IWUSR, + root, &host->make_it_fail)) + goto err_node; +#endif return; err_node: diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 8ae44d8..981cbe8 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -302,6 +302,9 @@ struct mmc_host { struct mmc_async_req *areq; /* active async req */ +#ifdef CONFIG_FAIL_MMC_REQUEST + u8 make_it_fail; +#endif unsigned long private[0] ____cacheline_aligned; }; diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c768bcd..330fc70 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1057,6 +1057,17 @@ 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 + help + Provide fault-injection capability for MMC IO. + This will make the mmc core return data errors. This is + useful for testing the error handling in the mmc block device + and how the mmc host driver handle retries from + the block device. + config FAULT_INJECTION_DEBUG_FS bool "Debugfs entries for fault-injection capabilities" depends on FAULT_INJECTION && SYSFS && DEBUG_FS