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@xxxxxxxxxx> 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@xxxxxxxxxx>
> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
> Reviewed-by: Venkatraman S <svenkatr@xxxxxx>
> Tested-by: Sourav Poddar<sourav.poddar@xxxxxx>
> Tested-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> ---
> 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
--
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