nvme: make SG_IO support optional

Translation SCSI commands to NVMe commands is rather pointless in general
as applications must not expext to be able to use SCSI commands on a
generic block device.

Make the huge translation layer optional and hope no one will ever enable
it in the future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
index 002a94abdbc45c7f20255b804efae684185283c9..5d6237391dcd4e3851390abe9b1412217d2428d8 100644 (file)
--- a/drivers/nvme/host/Kconfig
+++ b/drivers/nvme/host/Kconfig
@@ -8,3 +8,14 @@ config BLK_DEV_NVME
 
          To compile this driver as a module, choose M here: the
          module will be called nvme.
+
+config BLK_DEV_NVME_SCSI
+       bool "SCSI emulation for NVMe device nodes"
+       depends on BLK_DEV_NVME
+       ---help---
+         This adds support for the SG_IO ioctl on the NVMe character
+         and block devices nodes, as well a a translation for a small
+         number of selected SCSI commands to NVMe commands to the NVMe
+         driver.  If you don't know what this means you probably want
+         to say N here, and if you know what it means you probably
+         want to say N as well.

diff --git a/drivers/nvme/host/Makefile b/drivers/nvme/host/Makefile
index 3e26dc921c3831ec1164c71e217910cd268ef492..baf9f52bbfa5e241e0aa041169fece48e9e32f6f 100644 (file)
--- a/drivers/nvme/host/Makefile
+++ b/drivers/nvme/host/Makefile
@@ -1,4 +1,5 @@
 
 obj-$(CONFIG_BLK_DEV_NVME)     += nvme.o
 
-nvme-y         += core.o pci.o scsi.o lightnvm.o
+nvme-y                                 += core.o pci.o lightnvm.o
+nvme-$(CONFIG_BLK_DEV_NVME_SCSI)        += scsi.o

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 51f6fc83b05158909d52d115528f2eb604c59071..8da4a8a55c496c269c4b97691e4fa579720b2d46 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -467,10 +467,12 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
                return nvme_user_cmd(ns->ctrl, ns, (void __user *)arg);
        case NVME_IOCTL_SUBMIT_IO:
                return nvme_submit_io(ns, (void __user *)arg);
+#ifdef CONFIG_BLK_DEV_NVME_SCSI
        case SG_GET_VERSION_NUM:
                return nvme_sg_get_version_num((void __user *)arg);
        case SG_IO:
                return nvme_sg_io(ns, (void __user *)arg);
+#endif
        default:
                return -ENOTTY;
        }