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authorKristen Carlson Accardi <kristen.c.accardi@intel.com>2007-05-23 22:57:38 +0200
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-24 05:14:11 +0200
commit86ce18d7b7925bfd6b64c061828ca2a857ee83b8 (patch)
treeb753b7fd6d195aa7ed9eebc5a3917c5f20786260
parentNOHZ: Rate limit the local softirq pending warning output (diff)
downloadlinux-86ce18d7b7925bfd6b64c061828ca2a857ee83b8.tar.xz
linux-86ce18d7b7925bfd6b64c061828ca2a857ee83b8.zip
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>
-rw-r--r--Documentation/block/capability.txt15
-rw-r--r--block/genhd.c10
-rw-r--r--include/linux/genhd.h1
3 files changed, 25 insertions, 1 deletions
diff --git a/Documentation/block/capability.txt b/Documentation/block/capability.txt
new file mode 100644
index 000000000000..2f1729424ef4
--- /dev/null
+++ b/Documentation/block/capability.txt
@@ -0,0 +1,15 @@
+Generic Block Device Capability
+===============================================================================
+This file documents the sysfs file block/<disk>/capability
+
+capability is a hex word indicating which capabilities a specific disk
+supports. For more information on bits not listed here, see
+include/linux/genhd.h
+
+Capability Value
+-------------------------------------------------------------------------------
+GENHD_FL_MEDIA_CHANGE_NOTIFY 4
+ When this bit is set, the disk supports Asynchronous Notification
+ of media change events. These events will be broadcast to user
+ space via kernel uevent.
+
diff --git a/block/genhd.c b/block/genhd.c
index 93a2cf654597..7efa8bb25da9 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -423,7 +423,10 @@ static ssize_t disk_size_read(struct gendisk * disk, char *page)
{
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 @@ static struct disk_attribute disk_attr_size = {
.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 @@ static struct attribute * default_attrs[] = {
&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
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 4c03ee353e78..3fcfed2168a7 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -94,6 +94,7 @@ struct hd_struct {
#define GENHD_FL_REMOVABLE 1
#define GENHD_FL_DRIVERFS 2
+#define GENHD_FL_MEDIA_CHANGE_NOTIFY 4
#define GENHD_FL_CD 8
#define GENHD_FL_UP 16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32