[PATCH] UBI: Add ro-mode sysfs attribute

[PATCH] UBI: Add ro-mode sysfs attribute

[Ezequiel Garcia]

On certain situations, UBI may detect serious device corruption,
and switch to read-only mode to protect the data and allow debugging.
This commit exposes this ro-mode on sysfs, so it can be obtained
by userspace tools.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
---
 drivers/mtd/ubi/build.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c
index 22fd19c0c5d3..7091fca0fb44 100644
--- a/drivers/mtd/ubi/build.c
+++ b/drivers/mtd/ubi/build.c
@@ -149,6 +149,8 @@ static struct device_attribute dev_bgt_enabled =
 	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
 static struct device_attribute dev_mtd_num =
 	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
+static struct device_attribute dev_ro_mode =
+	__ATTR(ro_mode, S_IRUGO, dev_attribute_show, NULL);
 
 /**
  * ubi_volume_notify - send a volume change notification.
@@ -385,6 +387,8 @@ static ssize_t dev_attribute_show(struct device *dev,
 		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
 	else if (attr == &dev_mtd_num)
 		ret = sprintf(buf, "%d\n", ubi->mtd->index);
+	else if (attr == &dev_ro_mode)
+		ret = sprintf(buf, "%d\n", ubi->ro_mode);
 	else
 		ret = -EINVAL;
 
@@ -404,6 +408,7 @@ static struct attribute *ubi_dev_attrs[] = {
 	&dev_min_io_size.attr,
 	&dev_bgt_enabled.attr,
 	&dev_mtd_num.attr,
+	&dev_ro_mode.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(ubi_dev);
-- 
2.7.0

Re: [PATCH] UBI: Add ro-mode sysfs attribute

[Richard Weinberger]

Am 28.04.2016 um 20:28 schrieb Ezequiel Garcia:
> On certain situations, UBI may detect serious device corruption,
> and switch to read-only mode to protect the data and allow debugging.
> This commit exposes this ro-mode on sysfs, so it can be obtained
> by userspace tools.
> 
> Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>

Makes sense. Please also document the new attribute in
Documentation/ABI/stable/sysfs-class-ubi,

Thanks,
//richard