block: Add BLKROTATIONAL ioctl
Introduce an ioctl which permits applications to query whether a block
device is rotational.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index 7b72502..7c668c8 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -719,6 +719,9 @@
case BLKSECTGET:
return compat_put_ushort(arg,
queue_max_sectors(bdev_get_queue(bdev)));
+ case BLKROTATIONAL:
+ return compat_put_ushort(arg,
+ !blk_queue_nonrot(bdev_get_queue(bdev)));
case BLKRASET: /* compatible, but no compat_ptr (!) */
case BLKFRASET:
if (!capable(CAP_SYS_ADMIN))
diff --git a/block/ioctl.c b/block/ioctl.c
index ca939fc..337d207 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -278,6 +278,8 @@
return put_uint(arg, bdev_discard_zeroes_data(bdev));
case BLKSECTGET:
return put_ushort(arg, queue_max_sectors(bdev_get_queue(bdev)));
+ case BLKROTATIONAL:
+ return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev)));
case BLKRASET:
case BLKFRASET:
if(!capable(CAP_SYS_ADMIN))
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e0bc4ff..95dd911 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -319,6 +319,7 @@
#define BLKPBSZGET _IO(0x12,123)
#define BLKDISCARDZEROES _IO(0x12,124)
#define BLKSECDISCARD _IO(0x12,125)
+#define BLKROTATIONAL _IO(0x12,126)
#define BMAP_IOCTL 1 /* obsolete - kept for compatibility */
#define FIBMAP _IO(0x00,1) /* bmap access */
