The gpiommc configfs context structure needs locking, as configfs
does not lock access between files (or if it does, we shouldn't
depend on this to magically happen).

Signed-off-by: Michael Buesch



Index: linux-next/drivers/mmc/host/gpiommc.c
================================================== =================
--- linux-next.orig/drivers/mmc/host/gpiommc.c 2008-07-20 21:43:42.000000000 +0200
+++ linux-next/drivers/mmc/host/gpiommc.c 2008-07-21 12:10:55.000000000 +0200
@@ -143,6 +143,8 @@ struct gpiommc_configfs_device {
struct platform_device *pdev;
/* The configuration */
struct gpiommc_platform_data pdata;
+ /* Mutex to protect this structure */
+ struct mutex mutex;
};

#define GPIO_INVALID -1
@@ -233,6 +235,8 @@ static ssize_t gpiommc_config_attr_show(
unsigned int gpio;
int err = 0;

+ mutex_lock(&dev->mutex);
+
if (attr == &gpiommc_attr_DI) {
gpio = dev->pdata.pins.gpio_di;
if (gpio == GPIO_INVALID)
@@ -293,6 +297,8 @@ static ssize_t gpiommc_config_attr_show(
WARN_ON(1);
err = -ENOSYS;
out:
+ mutex_unlock(&dev->mutex);
+
return err ? err : count;
}

@@ -352,6 +358,8 @@ static ssize_t gpiommc_config_attr_store
int err = -EINVAL;
unsigned long data;

+ mutex_lock(&dev->mutex);
+
if (attr == &gpiommc_attr_register) {
err = strict_strtoul(page, 10, &data);
if (err)
@@ -477,6 +485,8 @@ static ssize_t gpiommc_config_attr_store
WARN_ON(1);
err = -ENOSYS;
out:
+ mutex_unlock(&dev->mutex);
+
return err ? err : count;
}

@@ -513,6 +523,7 @@ static struct config_item *gpiommc_make_
if (!dev)
return NULL;

+ mutex_init(&dev->mutex);
config_item_init_type_name(&dev->item, name,
&gpiommc_dev_ci_type);


--
Greetings Michael.
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