This patch prevents mmc core to be built as a module if mmc fault injection is selected.
Changes needed to resolve this: * remove fault inject module from core.c * export should_fail() and init_fault_attr_dentries() in fault-injection.c * update documentation fault-injection.txt
On 1 July 2011 18:55, Per Forlin per.forlin@linaro.org wrote:
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 per.forlin@linaro.org Acked-by: Kyungmin Park kyungmin.park@samsung.com Acked-by: Arnd Bergmann arnd@arndb.de Reviewed-by: Venkatraman S svenkatr@ti.com Tested-by: Sourav Poddarsourav.poddar@ti.com Tested-by: Linus Walleij linus.walleij@linaro.org
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 d2d7239..62a8cc7 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -23,6 +23,8 @@ #include <linux/log2.h> #include <linux/regulator/consumer.h> #include <linux/pm_runtime.h> +#include <linux/fault-inject.h> +#include <linux/random.h>
#include <linux/mmc/card.h> #include <linux/mmc/host.h> @@ -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);
This line prevents mmc core to be built as a module, since there will be two init_module (the mmc core one and this one) for the same module.
+#else /* CONFIG_FAIL_MMC_REQUEST */
+static void mmc_should_fail_request(struct mmc_host *host,
- struct mmc_request *mrq)
+{ +}
+static int __init fail_mmc_request_debugfs(void) +{ +} Add fail_mmc_request_debugfs here and call it from mmc_init()
+#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 59db6f2..0d0a48f 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -301,6 +301,9 @@ 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
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 for testing the error handling in the mmc block device
- and how the mmc host driver handle retries from
- the block device.
and test how the mmc host driver handle retries from