Currently, presence of direct_access() in block_device_operations
indicates support of DAX on its block device. Because
block_device_operations is instantiated with 'const', this DAX
capablity may not be enabled conditinally.
In preparation for supporting DAX to device-mapper devices, add
GENHD_FL_DAX to gendisk flags to indicate that this block device
supports DAX. This will allow to set the DAX capability based on
how mapped device is composed.
Signed-off-by: Toshi Kani <toshi.k...@hpe.com>
Cc: Jens Axboe <ax...@kernel.dk>
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Ross Zwisler <ross.zwis...@linux.intel.com>
Cc: Martin Schwidefsky <schwidef...@de.ibm.com>
Cc: Heiko Carstens <heiko.carst...@de.ibm.com>
Cc: <linux-s...@vger.kernel.org>
---
drivers/block/brd.c | 2 +-
drivers/nvdimm/pmem.c | 2 +-
drivers/s390/block/dcssblk.c | 1 +
include/linux/genhd.h | 2 +-
4 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index c04bd9b..43a6765 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -518,7 +518,7 @@ static struct brd_device *brd_alloc(int i)
disk->fops = &brd_fops;
disk->private_data = brd;
disk->queue = brd->brd_queue;
- disk->flags = GENHD_FL_EXT_DEVT;
+ disk->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DAX;
sprintf(disk->disk_name, "ram%d", i);
set_capacity(disk, rd_size * 2);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 608fc44..3847449 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -295,7 +295,7 @@ static int pmem_attach_disk(struct device *dev,
disk->fops = &pmem_fops;
disk->queue = q;
- disk->flags = GENHD_FL_EXT_DEVT;
+ disk->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DAX;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
disk->driverfs_dev = dev;
set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index bed53c4..60b1857 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -616,6 +616,7 @@ dcssblk_add_store(struct device *dev, struct
device_attribute *attr, const char
dev_info->gd->queue = dev_info->dcssblk_queue;
dev_info->gd->private_data = dev_info;
dev_info->gd->driverfs_dev = &dev_info->dev;
+ dev_info->gd->flags = GENHD_FL_DAX;
blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request);
blk_queue_logical_block_size(dev_info->dcssblk_queue, 4096);
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 359a8e4..9dc3a3d 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -131,7 +131,7 @@ struct hd_struct {
};
#define GENHD_FL_REMOVABLE 1
-/* 2 is unused */
+#define GENHD_FL_DAX 2
#define GENHD_FL_MEDIA_CHANGE_NOTIFY 4
#define GENHD_FL_CD 8
#define GENHD_FL_UP 16
