block: add GENHD_FL_NO_PART_SCAN
There are cases where suppressing partition scan is useful - e.g. for
lo devices and pseudo SATA devices which advertise to be a disk but
get upset on partition scan (some port multiplier control devices show
such behavior).
This patch adds GENHD_FL_NO_PART_SCAN which suppresses partition scan
regardless of the number of possible partitions. disk_partitionable()
is renamed to disk_part_scan_enabled() as suppressing partition scan
doesn't imply the device can't be partitioned using
BLKPG_ADD/DEL_PARTITION calls from userland. show_partition() now
directly tests disk_max_parts() to maintain backward-compatibility.
-v2: Updated to make it clear that only partition scan is suppressed
not partitioning itself as suggested by Kay Sievers.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 02fa469..6d18f35 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -128,6 +128,7 @@
#define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
#define GENHD_FL_NATIVE_CAPACITY 128
#define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE 256
+#define GENHD_FL_NO_PART_SCAN 512
enum {
DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
@@ -234,9 +235,10 @@
return disk->minors;
}
-static inline bool disk_partitionable(struct gendisk *disk)
+static inline bool disk_part_scan_enabled(struct gendisk *disk)
{
- return disk_max_parts(disk) > 1;
+ return disk_max_parts(disk) > 1 &&
+ !(disk->flags & GENHD_FL_NO_PART_SCAN);
}
static inline dev_t disk_devt(struct gendisk *disk)