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nvme: Remove SCSI translations

PATCH Superseded Keith Busch 6 participants 6 messages Jun 14, 2017 – Jun 15, 2017 NVMe

v1 of 2 Superseded Latest is v2 →

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Keith Busch

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#0 lore raw

PATCH 1/1 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: 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. The config option has been disabled by default for quite some time now, so hopefully it's safe to remove. If not, this will force people to do the right thing.

Signed-off-by Keith Busch <keith.busch at intel.com>
---
 drivers/nvme/host/Kconfig |   12 -
 drivers/nvme/host/core.c  |   11 -
 drivers/nvme/host/scsi.c  | 2460 ---------------------------------------------
 3 files changed, 2483 deletions(-)
 delete mode 100644 drivers/nvme/host/scsi.c
drivers/nvme/host/Kconfig +0 -12
index 90745a6..46d6cb1 100644
@@ -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 +0 -11
index 4554c60..598d5a0 100644
@@ -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"

@@ -936,12 +935,6 @@ 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)

@@ -958,10 +951,6 @@ 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/scsi.c deleted +0 -2460

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Signature · 1 line
2.5.5
maintainer
#1 lore raw

PATCH 1/1 nvme: Remove SCSI translations

Quoted 11 lines · Keith Busch

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: 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. The config option has been disabled by default for quite some time now, so hopefully it's safe to remove. If not, this will force people to do the right thing.

Signed-off-by Keith Busch <keith.busch at intel.com>
Acked-by Jens Axboe <axboe at kernel.dk>
Signature · 1 line
Jens Axboe
#2 lore raw

PATCH 1/1 nvme: Remove SCSI translations

In reply to Keith Busch

Keith,

Quoted 10 lines

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: 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. The config option has been disabled by default for quite some time now, so hopefully it's safe to remove. If not, this will force people to do the right thing.

Good riddance!

Reviewed-by Martin K. Petersen <martin.petersen at oracle.com>
Signature · 1 line
Martin K. Petersen	Oracle Linux Engineering
maintainer
#3 lore raw

PATCH 1/1 nvme: Remove SCSI translations

In reply to Keith Busch
Quoted 11 lines · Keith Busch

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: 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. The config option has been disabled by default for quite some time now, so hopefully it's safe to remove. If not, this will force people to do the right thing.

Signed-off-by Keith Busch <keith.busch at intel.com>

I like this but would like to hear from the SuSE folks first as indicated in the other mail.

Also at least the nvme_get_log_page and nvme_set_features functions in core.c are unused after this patch and can be removed as well.

#5 lore raw

PATCH 1/1 nvme: Remove SCSI translations

Quoted 1 line · Sagi Grimberg

Beautiful patch,

Yes indeed.

Reviewed-by Max Gurtovoy <maxg at mellanox.com>
Quoted 8 lines
Reviewed-by Sagi Grimberg <sagi at grimberg.me>

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