nvme: Remove SCSI translations

The SCSI-to-NVMe translations were added to assist storage applications
utilizing SG_IO transitioning to NVMe. It was always recommended,
however, to use native NVMe for device management as too much is lost
in translation and the maintenance burden in keeping this kludgey
layer around has been neglected such that much of the translations are
completely broken.

This patch removes SG_IO handling from NVMe to avoid any confusion
regarding maintenance support for this interface. The config option for
NVMe SCSI emulation has been disabled by default since 4.5. The driver
has supported native nvme user commands since the beginning, and native
tooling is publicly available for use or as reference for anyone writing
their own tools, so there's no excuse for hanging onto a broken crutch.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Guan Junxiong <guanjunxiong@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/Kconfig

@@ -13,18 +13,6 @@ 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 NVME_CORE
-	---help---
-	  This adds support for the SG_IO ioctl on the NVMe character
-	  and block devices nodes, as well as 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, unless you run a distro that abuses the SCSI
-	  emulation to provide stable device names for mount by id, like
-	  some OpenSuSE and SLES versions.
-
 config NVME_FABRICS
 	tristate
 

drivers/nvme/host/core.c

@@ -27,7 +27,6 @@
 #include <linux/nvme_ioctl.h>
 #include <linux/t10-pi.h>
 #include <linux/pm_qos.h>
-#include <scsi/sg.h>
 #include <asm/unaligned.h>
 
 #include "nvme.h"
@@ -756,7 +755,7 @@ void nvme_stop_keep_alive(struct nvme_ctrl *ctrl)
 }
 EXPORT_SYMBOL_GPL(nvme_stop_keep_alive);
 
-int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
+static int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id)
 {
 	struct nvme_command c = { };
 	int error;
@@ -857,7 +856,7 @@ static int nvme_identify_ns_list(struct nvme_ctrl *dev, unsigned nsid, __le32 *n
 	return nvme_submit_sync_cmd(dev->admin_q, &c, ns_list, 0x1000);
 }
 
-int nvme_identify_ns(struct nvme_ctrl *dev, unsigned nsid,
+static int nvme_identify_ns(struct nvme_ctrl *dev, unsigned nsid,
 		struct nvme_id_ns **id)
 {
 	struct nvme_command c = { };
@@ -879,26 +878,7 @@ int nvme_identify_ns(struct nvme_ctrl *dev, unsigned nsid,
 	return error;
 }
 
-int nvme_get_features(struct nvme_ctrl *dev, unsigned fid, unsigned nsid,
-		      void *buffer, size_t buflen, u32 *result)
-{
-	struct nvme_command c;
-	union nvme_result res;
-	int ret;
-
-	memset(&c, 0, sizeof(c));
-	c.features.opcode = nvme_admin_get_features;
-	c.features.nsid = cpu_to_le32(nsid);
-	c.features.fid = cpu_to_le32(fid);
-
-	ret = __nvme_submit_sync_cmd(dev->admin_q, &c, &res, buffer, buflen, 0,
-			NVME_QID_ANY, 0, 0);
-	if (ret >= 0 && result)
-		*result = le32_to_cpu(res.u32);
-	return ret;
-}
-
-int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
+static int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
 		      void *buffer, size_t buflen, u32 *result)
 {
 	struct nvme_command c;
@@ -917,28 +897,6 @@ int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
 	return ret;
 }
 
-int nvme_get_log_page(struct nvme_ctrl *dev, struct nvme_smart_log **log)
-{
-	struct nvme_command c = { };
-	int error;
-
-	c.common.opcode = nvme_admin_get_log_page,
-	c.common.nsid = cpu_to_le32(0xFFFFFFFF),
-	c.common.cdw10[0] = cpu_to_le32(
-			(((sizeof(struct nvme_smart_log) / 4) - 1) << 16) |
-			 NVME_LOG_SMART),
-
-	*log = kmalloc(sizeof(struct nvme_smart_log), GFP_KERNEL);
-	if (!*log)
-		return -ENOMEM;
-
-	error = nvme_submit_sync_cmd(dev->admin_q, &c, *log,
-			sizeof(struct nvme_smart_log));
-	if (error)
-		kfree(*log);
-	return error;
-}
-
 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count)
 {
 	u32 q_count = (*count - 1) | ((*count - 1) << 16);
@@ -1074,12 +1032,6 @@ 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:
 #ifdef CONFIG_NVM
 		if (ns->ndev)
@@ -1096,10 +1048,6 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
 static int nvme_compat_ioctl(struct block_device *bdev, fmode_t mode,
 			unsigned int cmd, unsigned long arg)
 {
-	switch (cmd) {
-	case SG_IO:
-		return -ENOIOCTLCMD;
-	}
 	return nvme_ioctl(bdev, mode, cmd, arg);
 }
 #else

drivers/nvme/host/nvme.h

@@ -319,25 +319,11 @@ int __nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
 		void __user *ubuffer, unsigned bufflen,
 		void __user *meta_buffer, unsigned meta_len, u32 meta_seed,
 		u32 *result, unsigned timeout);
-int nvme_identify_ctrl(struct nvme_ctrl *dev, struct nvme_id_ctrl **id);
-int nvme_identify_ns(struct nvme_ctrl *dev, unsigned nsid,
-		struct nvme_id_ns **id);
-int nvme_get_log_page(struct nvme_ctrl *dev, struct nvme_smart_log **log);
-int nvme_get_features(struct nvme_ctrl *dev, unsigned fid, unsigned nsid,
-		      void *buffer, size_t buflen, u32 *result);
-int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword11,
-		      void *buffer, size_t buflen, u32 *result);
 int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count);
 void nvme_start_keep_alive(struct nvme_ctrl *ctrl);
 void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
 int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
 
-struct sg_io_hdr;
-
-int nvme_sg_io(struct nvme_ns *ns, struct sg_io_hdr __user *u_hdr);
-int nvme_sg_io32(struct nvme_ns *ns, unsigned long arg);
-int nvme_sg_get_version_num(int __user *ip);
-
 #ifdef CONFIG_NVM
 int nvme_nvm_ns_supported(struct nvme_ns *ns, struct nvme_id_ns *id);
 int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node);