genhd: expose AN to user space
Allow user space to determine if a disk supports Asynchronous Notification of
media changes. This is done by adding a new sysfs file "capability_flags",
which is documented in (insert file name). This sysfs file will export all
disk capabilities flags to user space. We also define a new flag to define
the media change notification capability.
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/genhd.c b/block/genhd.c
index 93a2cf6..7efa8bb 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -423,7 +423,10 @@
{
return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
}
-
+static ssize_t disk_capability_read(struct gendisk *disk, char *page)
+{
+ return sprintf(page, "%x\n", disk->flags);
+}
static ssize_t disk_stats_read(struct gendisk * disk, char *page)
{
preempt_disable();
@@ -466,6 +469,10 @@
.attr = {.name = "size", .mode = S_IRUGO },
.show = disk_size_read
};
+static struct disk_attribute disk_attr_capability = {
+ .attr = {.name = "capability", .mode = S_IRUGO },
+ .show = disk_capability_read
+};
static struct disk_attribute disk_attr_stat = {
.attr = {.name = "stat", .mode = S_IRUGO },
.show = disk_stats_read
@@ -506,6 +513,7 @@
&disk_attr_removable.attr,
&disk_attr_size.attr,
&disk_attr_stat.attr,
+ &disk_attr_capability.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&disk_attr_fail.attr,
#endif