[PATCH] block: hide badblocks attribute by default

From: Dan Williams
Date: Thu Apr 27 2017 - 17:52:35 EST


Commit 99e6608c9e74 "block: Add badblock management for gendisks"
allowed for drivers like pmem and software-raid to advertise a list of
bad media areas. However, it inadvertently added a 'badblocks' to all
block devices. Lets clean this up by having the 'badblocks' attribute
not be visible when the driver has not populated a 'struct badblocks'
instance in the gendisk.

Cc: Jens Axboe <axboe@xxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Reported-by: Vishal Verma <vishal.l.verma@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
block/genhd.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index a9c516a8b37d..12acd48e1210 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1060,8 +1060,19 @@ static struct attribute *disk_attrs[] = {
NULL
};

+static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
+{
+ struct device *dev = container_of(kobj, typeof(*dev), kobj);
+ struct gendisk *disk = dev_to_disk(dev);
+
+ if (a == &dev_attr_badblocks.attr && !disk->bb)
+ return 0;
+ return a->mode;
+}
+
static struct attribute_group disk_attr_group = {
.attrs = disk_attrs,
+ .is_visible = disk_visible,
};

static const struct attribute_group *disk_attr_groups[] = {