Linux Virtualization - Dec 2019 - [PATCH 00/24] block, scsi: final compat_ioctl cleanup

Hi Jens, James and Martin,

This series concludes the work I did for linux-5.5 on the compat_ioctl()
cleanup, killing off fs/compat_ioctl.c and block/compat_ioctl.c by moving
everything into drivers.

Overall this would be a reduction both in complexity and line count, but
as I'm also adding documentation the overall number of lines increases
in the end.

My plan was originally to keep the SCSI and block parts separate.
This did not work easily because of interdependencies: I cannot
do the final SCSI cleanup in a good way without first addressing the
CDROM ioctls, so this is one series that I hope could be merged through
either the block or the scsi git trees, or possibly both if you can
pull in the same branch.

The series comes in these steps:

1. clean up the sg v3 interface as suggested by Linus. I have
   talked about this with Doug Gilbert as well, and he would
   rebase his sg v4 patches on top of "compat: scsi: sg: fix v3
   compat read/write interface"

2. Four patches for missing block compat_ioctl handlers, to be
   backported into stable kernels. Separate patches because they
   are needed in different stable versions.

3. Actually moving handlers out of block/compat_ioctl.c and
   block/scsi_ioctl.c into drivers, mixed in with cleanup
   patches

4. Document how to do this right. I keep getting asked about this,
   and it helps to point to some documentation file.

The series is avaialable for testing at [1].

       Arnd

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/arnd/playground.git/log/?h=compat-ioctl-endgame

Arnd Bergmann (24):
  compat: ARM64: always include asm-generic/compat.h
  compat: scsi: sg: fix v3 compat read/write interface
  compat_ioctl: block: handle BLKREPORTZONE/BLKRESETZONE
  compat_ioctl: block: handle BLKGETZONESZ/BLKGETNRZONES
  compat_ioctl: block: handle add zone open, close and finish ioctl
  compat_ioctl: block: handle Persistent Reservations
  compaT_ioctl: ubd, aoe: use blkdev_compat_ptr_ioctl
  compat_ioctl: move CDROM_SEND_PACKET handling into scsi
  compat_ioctl: move CDROMREADADIO to cdrom.c
  compat_ioctl: cdrom: handle CDROM_LAST_WRITTEN
  compat_ioctl: block: handle cdrom compat ioctl in non-cdrom drivers
  compat_ioctl: add scsi_compat_ioctl
  compat_ioctl: bsg: add handler
  compat_ioctl: ide: floppy: add handler
  compat_ioctl: scsi: move ioctl handling into drivers
  compat_ioctl: move sys_compat_ioctl() to ioctl.c
  compat_ioctl: simplify the implementation
  compat_ioctl: move cdrom commands into cdrom.c
  compat_ioctl: scsi: handle HDIO commands from drivers
  compat_ioctl: move HDIO ioctl handling into drivers/ide
  compat_ioctl: block: move blkdev_compat_ioctl() into ioctl.c
  compat_ioctl: block: simplify compat_blkpg_ioctl()
  compat_ioctl: simplify up block/ioctl.c
  Documentation: document ioctl interfaces better

 Documentation/core-api/index.rst       |   1 +
 Documentation/core-api/ioctl.rst       | 250 +++++++++++++++
 arch/arm64/include/asm/compat.h        |   5 +-
 arch/um/drivers/ubd_kern.c             |   1 +
 block/Makefile                         |   1 -
 block/bsg.c                            |   1 +
 block/compat_ioctl.c                   | 411 -------------------------
 block/ioctl.c                          | 319 +++++++++++++++----
 block/scsi_ioctl.c                     | 214 ++++++++-----
 drivers/ata/libata-scsi.c              |   9 +
 drivers/block/aoe/aoeblk.c             |   1 +
 drivers/block/floppy.c                 |   3 +
 drivers/block/paride/pcd.c             |   3 +
 drivers/block/paride/pd.c              |   1 +
 drivers/block/paride/pf.c              |   1 +
 drivers/block/pktcdvd.c                |  26 +-
 drivers/block/sunvdc.c                 |   1 +
 drivers/block/virtio_blk.c             |   3 +
 drivers/block/xen-blkfront.c           |   1 +
 drivers/cdrom/cdrom.c                  |  35 ++-
 drivers/cdrom/gdrom.c                  |   3 +
 drivers/ide/ide-cd.c                   |  40 +++
 drivers/ide/ide-disk.c                 |   3 +
 drivers/ide/ide-floppy.c               |   4 +
 drivers/ide/ide-floppy.h               |   2 +
 drivers/ide/ide-floppy_ioctl.c         |  35 +++
 drivers/ide/ide-gd.c                   |  14 +
 drivers/ide/ide-ioctls.c               |  47 ++-
 drivers/ide/ide-tape.c                 |  14 +
 drivers/scsi/aic94xx/aic94xx_init.c    |   3 +
 drivers/scsi/ch.c                      |   9 +-
 drivers/scsi/hisi_sas/hisi_sas_v1_hw.c |   3 +
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c |   3 +
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c |   3 +
 drivers/scsi/ipr.c                     |   3 +
 drivers/scsi/isci/init.c               |   3 +
 drivers/scsi/mvsas/mv_init.c           |   3 +
 drivers/scsi/pm8001/pm8001_init.c      |   3 +
 drivers/scsi/scsi_ioctl.c              |  54 +++-
 drivers/scsi/sd.c                      |  50 ++-
 drivers/scsi/sg.c                      | 169 +++++-----
 drivers/scsi/sr.c                      |  53 +++-
 drivers/scsi/st.c                      |  51 +--
 fs/Makefile                            |   2 +-
 fs/compat_ioctl.c                      | 261 ----------------
 fs/internal.h                          |   6 -
 fs/ioctl.c                             | 131 +++++---
 include/linux/blkdev.h                 |   7 +
 include/linux/falloc.h                 |   2 -
 include/linux/fs.h                     |   4 -
 include/linux/ide.h                    |   2 +
 include/linux/libata.h                 |   6 +
 include/scsi/scsi_ioctl.h              |   1 +
 include/scsi/sg.h                      |  30 ++
 54 files changed, 1249 insertions(+), 1062 deletions(-)
 create mode 100644 Documentation/core-api/ioctl.rst
 delete mode 100644 block/compat_ioctl.c
 delete mode 100644 fs/compat_ioctl.c

-- 
2.20.0

Cc: corbet at lwn.net
Cc: catalin.marinas at arm.com
Cc: will at kernel.org
Cc: jdike at addtoit.com
Cc: richard at nod.at
Cc: anton.ivanov at cambridgegreys.com
Cc: fujita.tomonori at lab.ntt.co.jp
Cc: justin at coraid.com
Cc: efremov at linux.com
Cc: tim at cyberelk.net
Cc: mst at redhat.com
Cc: jasowang at redhat.com
Cc: pbonzini at redhat.com
Cc: stefanha at redhat.com
Cc: boris.ostrovsky at oracle.com
Cc: jgross at suse.com
Cc: sstabellini at kernel.org
Cc: konrad.wilk at oracle.com
Cc: roger.pau at citrix.com
Cc: bp at alien8.de
Cc: davem at davemloft.net
Cc: john.garry at huawei.com
Cc: brking at us.ibm.com
Cc: intel-linux-scu at intel.com
Cc: artur.paszkiewicz at intel.com
Cc: jinpu.wang at cloud.ionos.com
Cc: dgilbert at interlog.com
Cc: Kai.Makisara at kolumbus.fi
Cc: arnd at arndb.de
Cc: damien.lemoal at hgst.com
Cc: hare at suse.com
Cc: linux-doc at vger.kernel.org
Cc: linux-kernel at vger.kernel.org
Cc: linux-block at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-um at lists.infradead.org
Cc: linux-scsi at vger.kernel.org
Cc: linux-ide at vger.kernel.org
Cc: virtualization at lists.linux-foundation.org
Cc: xen-devel at lists.xenproject.org
Cc: linux-fsdevel at vger.kernel.org

Each driver calling scsi_ioctl() gets an equivalent compat_ioctl()
handler that implements the same commands by calling scsi_compat_ioctl().

The scsi_cmd_ioctl() and scsi_cmd_blk_ioctl() functions are compatible
at this point, so any driver that calls those can do so for both native
and compat mode, with the argument passed through compat_ptr().

With this, we can remove the entries from fs/compat_ioctl.c.  The new
code is larger, but should be easier to maintain and keep updated with
newly added commands.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
 drivers/block/virtio_blk.c |   3 +
 drivers/scsi/ch.c          |   9 ++-
 drivers/scsi/sd.c          |  50 ++++++--------
 drivers/scsi/sg.c          |  44 ++++++++-----
 drivers/scsi/sr.c          |  57 ++++++++++++++--
 drivers/scsi/st.c          |  51 ++++++++------
 fs/compat_ioctl.c          | 132 +------------------------------------
 7 files changed, 142 insertions(+), 204 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 7ffd719d89de..fbbf18ac1d5d 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -405,6 +405,9 @@ static int virtblk_getgeo(struct block_device *bd, struct
hd_geometry *geo)
 
 static const struct block_device_operations virtblk_fops = {
 	.ioctl  = virtblk_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = blkdev_compat_ptr_ioctl,
+#endif
 	.owner  = THIS_MODULE,
 	.getgeo = virtblk_getgeo,
 };
diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
index 76751d6c7f0d..ed5f4a6ae270 100644
--- a/drivers/scsi/ch.c
+++ b/drivers/scsi/ch.c
@@ -872,6 +872,10 @@ static long ch_ioctl_compat(struct file * file,
 			    unsigned int cmd, unsigned long arg)
 {
 	scsi_changer *ch = file->private_data;
+	int retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
+							file->f_flags & O_NDELAY);
+	if (retval)
+		return retval;
 
 	switch (cmd) {
 	case CHIOGPARAMS:
@@ -883,7 +887,7 @@ static long ch_ioctl_compat(struct file * file,
 	case CHIOINITELEM:
 	case CHIOSVOLTAG:
 		/* compatible */
-		return ch_ioctl(file, cmd, arg);
+		return ch_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
 	case CHIOGSTATUS32:
 	{
 		struct changer_element_status32 ces32;
@@ -898,8 +902,7 @@ static long ch_ioctl_compat(struct file * file,
 		return ch_gstatus(ch, ces32.ces_type, data);
 	}
 	default:
-		// return scsi_ioctl_compat(ch->device, cmd, (void*)arg);
-		return -ENOIOCTLCMD;
+		return scsi_compat_ioctl(ch->device, cmd, compat_ptr(arg));
 
 	}
 }
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index cea625906440..5afb0046b12a 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1465,13 +1465,12 @@ static int sd_getgeo(struct block_device *bdev, struct
hd_geometry *geo)
  *	Note: most ioctls are forward onto the block subsystem or further
  *	down in the scsi subsystem.
  **/
-static int sd_ioctl(struct block_device *bdev, fmode_t mode,
-		    unsigned int cmd, unsigned long arg)
+static int sd_ioctl_common(struct block_device *bdev, fmode_t mode,
+			   unsigned int cmd, void __user *p)
 {
 	struct gendisk *disk = bdev->bd_disk;
 	struct scsi_disk *sdkp = scsi_disk(disk);
 	struct scsi_device *sdp = sdkp->device;
-	void __user *p = (void __user *)arg;
 	int error;
     
 	SCSI_LOG_IOCTL(1, sd_printk(KERN_INFO, sdkp, "sd_ioctl: disk=%s, "
@@ -1507,9 +1506,6 @@ static int sd_ioctl(struct block_device *bdev, fmode_t
mode,
 			break;
 		default:
 			error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
-			if (error != -ENOTTY)
-				break;
-			error = scsi_ioctl(sdp, cmd, p);
 			break;
 	}
 out:
@@ -1691,39 +1687,31 @@ static void sd_rescan(struct device *dev)
 	revalidate_disk(sdkp->disk);
 }
 
+static int sd_ioctl(struct block_device *bdev, fmode_t mode,
+		    unsigned int cmd, unsigned long arg)
+{
+	void __user *p = (void __user *)arg;
+	int ret;
+
+	ret = sd_ioctl_common(bdev, mode, cmd, p);
+	if (ret != -ENOTTY)
+		return ret;
+
+	return scsi_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p);
+}
 
 #ifdef CONFIG_COMPAT
-/* 
- * This gets directly called from VFS. When the ioctl 
- * is not recognized we go back to the other translation paths. 
- */
 static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
 			   unsigned int cmd, unsigned long arg)
 {
-	struct gendisk *disk = bdev->bd_disk;
-	struct scsi_disk *sdkp = scsi_disk(disk);
-	struct scsi_device *sdev = sdkp->device;
 	void __user *p = compat_ptr(arg);
-	int error;
-
-	error = scsi_verify_blk_ioctl(bdev, cmd);
-	if (error < 0)
-		return error;
+	int ret;
 
-	error = scsi_ioctl_block_when_processing_errors(sdev, cmd,
-			(mode & FMODE_NDELAY) != 0);
-	if (error)
-		return error;
+	ret = sd_ioctl_common(bdev, mode, cmd, p);
+	if (ret != -ENOTTY)
+		return ret;
 
-	if (is_sed_ioctl(cmd))
-		return sed_ioctl(sdkp->opal_dev, cmd, p);
-	       
-	/* 
-	 * Let the static ioctl translation table take care of it.
-	 */
-	if (!sdev->host->hostt->compat_ioctl)
-		return -ENOIOCTLCMD; 
-	return sdev->host->hostt->compat_ioctl(sdev, cmd, p);
+	return scsi_compat_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p);
 }
 #endif
 
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 985546aac236..08efcee7a34d 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -910,19 +910,14 @@ static int put_compat_request_table(struct
compat_sg_req_info __user *o,
 #endif
 
 static long
-sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
+sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
+		unsigned int cmd_in, void __user *p)
 {
-	void __user *p = (void __user *)arg;
 	int __user *ip = p;
 	int result, val, read_only;
-	Sg_device *sdp;
-	Sg_fd *sfp;
 	Sg_request *srp;
 	unsigned long iflags;
 
-	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
-		return -ENXIO;
-
 	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
 				   "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
 	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
@@ -1145,29 +1140,44 @@ sg_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
 			cmd_in, filp->f_flags & O_NDELAY);
 	if (result)
 		return result;
+
+	return -ENOIOCTLCMD;
+}
+
+static long
+sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
+{
+	void __user *p = (void __user *)arg;
+	Sg_device *sdp;
+	Sg_fd *sfp;
+	int ret;
+
+	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
+		return -ENXIO;
+
+	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
+
 	return scsi_ioctl(sdp->device, cmd_in, p);
 }
 
 #ifdef CONFIG_COMPAT
 static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned
long arg)
 {
+	void __user *p = compat_ptr(arg);
 	Sg_device *sdp;
 	Sg_fd *sfp;
-	struct scsi_device *sdev;
+	int ret;
 
 	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
 		return -ENXIO;
 
-	sdev = sdp->device;
-	if (sdev->host->hostt->compat_ioctl) { 
-		int ret;
-
-		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user
*)arg);
-
+	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
+	if (ret != -ENOIOCTLCMD)
 		return ret;
-	}
-	
-	return -ENOIOCTLCMD;
+
+	return scsi_compat_ioctl(sdp->device, cmd_in, p);
 }
 #endif
 
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 4664fdf75c0f..6033a886c42c 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -38,6 +38,7 @@
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/bio.h>
+#include <linux/compat.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/cdrom.h>
@@ -598,6 +599,55 @@ static int sr_block_ioctl(struct block_device *bdev,
fmode_t mode, unsigned cmd,
 	return ret;
 }
 
+#ifdef CONFIG_COMPAT
+static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode,
unsigned cmd,
+			  unsigned long arg)
+{
+	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
+	struct scsi_device *sdev = cd->device;
+	void __user *argp = compat_ptr(arg);
+	int ret;
+
+	mutex_lock(&sr_mutex);
+
+	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
+			(mode & FMODE_NDELAY) != 0);
+	if (ret)
+		goto out;
+
+	scsi_autopm_get_device(sdev);
+
+	/*
+	 * Send SCSI addressing ioctls directly to mid level, send other
+	 * ioctls to cdrom/block level.
+	 */
+	switch (cmd) {
+	case SCSI_IOCTL_GET_IDLUN:
+	case SCSI_IOCTL_GET_BUS_NUMBER:
+		ret = scsi_compat_ioctl(sdev, cmd, argp);
+		goto put;
+	}
+
+	/*
+	 * CDROM ioctls are handled in the block layer, but
+	 * do the scsi blk ioctls here.
+	 */
+	ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
+	if (ret != -ENOTTY)
+		return ret;
+
+	ret = scsi_compat_ioctl(sdev, cmd, argp);
+
+put:
+	scsi_autopm_put_device(sdev);
+
+out:
+	mutex_unlock(&sr_mutex);
+	return ret;
+
+}
+#endif
+
 static unsigned int sr_block_check_events(struct gendisk *disk,
 					  unsigned int clearing)
 {
@@ -641,12 +691,11 @@ static const struct block_device_operations sr_bdops  
.open		= sr_block_open,
 	.release	= sr_block_release,
 	.ioctl		= sr_block_ioctl,
+#ifdef CONFIG_COMPAT
+	.ioctl		= sr_block_compat_ioctl,
+#endif
 	.check_events	= sr_block_check_events,
 	.revalidate_disk = sr_block_revalidate_disk,
-	/* 
-	 * No compat_ioctl for now because sr_block_ioctl never
-	 * seems to pass arbitrary ioctls down to host drivers.
-	 */
 };
 
 static int sr_open(struct cdrom_device_info *cdi, int purpose)
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 9e3fff2de83e..393f3019ccac 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -3501,7 +3501,7 @@ static int partition_tape(struct scsi_tape *STp, int size)
 
 
 /* The ioctl command */
-static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
+static long st_ioctl_common(struct file *file, unsigned int cmd_in, void __user
*p)
 {
 	int i, cmd_nr, cmd_type, bt;
 	int retval = 0;
@@ -3509,7 +3509,6 @@ static long st_ioctl(struct file *file, unsigned int
cmd_in, unsigned long arg)
 	struct scsi_tape *STp = file->private_data;
 	struct st_modedef *STm;
 	struct st_partstat *STps;
-	void __user *p = (void __user *)arg;
 
 	if (mutex_lock_interruptible(&STp->lock))
 		return -ERESTARTSYS;
@@ -3824,9 +3823,19 @@ static long st_ioctl(struct file *file, unsigned int
cmd_in, unsigned long arg)
 	}
 	mutex_unlock(&STp->lock);
 	switch (cmd_in) {
+		case SCSI_IOCTL_STOP_UNIT:
+			/* unload */
+			retval = scsi_ioctl(STp->device, cmd_in, p);
+			if (!retval) {
+				STp->rew_at_close = 0;
+				STp->ready = ST_NO_TAPE;
+			}
+			return retval;
+
 		case SCSI_IOCTL_GET_IDLUN:
 		case SCSI_IOCTL_GET_BUS_NUMBER:
 			break;
+
 		default:
 			if ((cmd_in == SG_IO ||
 			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
@@ -3840,42 +3849,46 @@ static long st_ioctl(struct file *file, unsigned int
cmd_in, unsigned long arg)
 				return i;
 			break;
 	}
-	retval = scsi_ioctl(STp->device, cmd_in, p);
-	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
-		STp->rew_at_close = 0;
-		STp->ready = ST_NO_TAPE;
-	}
-	return retval;
+	return -ENOTTY;
 
  out:
 	mutex_unlock(&STp->lock);
 	return retval;
 }
 
+static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
+{
+	void __user *p = (void __user *)arg;
+	struct scsi_tape *STp = file->private_data;
+	int ret;
+
+	ret = st_ioctl_common(file, cmd_in, p);
+	if (ret != -ENOTTY)
+		return ret;
+
+	return scsi_ioctl(STp->device, cmd_in, p);
+}
+
 #ifdef CONFIG_COMPAT
 static long st_compat_ioctl(struct file *file, unsigned int cmd_in, unsigned
long arg)
 {
 	void __user *p = compat_ptr(arg);
 	struct scsi_tape *STp = file->private_data;
-	struct scsi_device *sdev = STp->device;
-	int ret = -ENOIOCTLCMD;
+	int ret;
 
 	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
 	switch (cmd_in) {
-	case MTIOCTOP:
-		return st_ioctl(file, MTIOCTOP, (unsigned long)p);
 	case MTIOCPOS32:
-		return st_ioctl(file, MTIOCPOS, (unsigned long)p);
+		return st_ioctl_common(file, MTIOCPOS, p);
 	case MTIOCGET32:
-		return st_ioctl(file, MTIOCGET, (unsigned long)p);
+		return st_ioctl_common(file, MTIOCGET, p);
 	}
 
-	if (sdev->host->hostt->compat_ioctl) { 
+	ret = st_ioctl_common(file, cmd_in, p);
+	if (ret != -ENOTTY)
+		return ret;
 
-		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user
*)arg);
-
-	}
-	return ret;
+	return scsi_compat_ioctl(STp->device, cmd_in, p);
 }
 #endif
 
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index 358ea2ecf36b..ab4471f469e6 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -36,109 +36,11 @@
 
 #include "internal.h"
 
-#ifdef CONFIG_BLOCK
-#include <linux/cdrom.h>
-#include <linux/fd.h>
-#include <scsi/scsi.h>
-#include <scsi/scsi_ioctl.h>
-#include <scsi/sg.h>
-#endif
-
 #include <linux/uaccess.h>
 #include <linux/watchdog.h>
 
 #include <linux/hiddev.h>
 
-
-#include <linux/sort.h>
-
-/*
- * simple reversible transform to make our table more evenly
- * distributed after sorting.
- */
-#define XFORM(i) (((i) ^ ((i) << 27) ^ ((i) << 17)) &
0xffffffff)
-
-#define COMPATIBLE_IOCTL(cmd) XFORM((u32)cmd),
-static unsigned int ioctl_pointer[] = {
-#ifdef CONFIG_BLOCK
-/* Big S */
-COMPATIBLE_IOCTL(SCSI_IOCTL_GET_IDLUN)
-COMPATIBLE_IOCTL(SCSI_IOCTL_DOORLOCK)
-COMPATIBLE_IOCTL(SCSI_IOCTL_DOORUNLOCK)
-COMPATIBLE_IOCTL(SCSI_IOCTL_TEST_UNIT_READY)
-COMPATIBLE_IOCTL(SCSI_IOCTL_GET_BUS_NUMBER)
-COMPATIBLE_IOCTL(SCSI_IOCTL_SEND_COMMAND)
-COMPATIBLE_IOCTL(SCSI_IOCTL_PROBE_HOST)
-COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI)
-#endif
-#ifdef CONFIG_BLOCK
-/* SG stuff */
-COMPATIBLE_IOCTL(SG_IO)
-COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE)
-COMPATIBLE_IOCTL(SG_SET_TIMEOUT)
-COMPATIBLE_IOCTL(SG_GET_TIMEOUT)
-COMPATIBLE_IOCTL(SG_EMULATED_HOST)
-COMPATIBLE_IOCTL(SG_GET_TRANSFORM)
-COMPATIBLE_IOCTL(SG_SET_RESERVED_SIZE)
-COMPATIBLE_IOCTL(SG_GET_RESERVED_SIZE)
-COMPATIBLE_IOCTL(SG_GET_SCSI_ID)
-COMPATIBLE_IOCTL(SG_SET_FORCE_LOW_DMA)
-COMPATIBLE_IOCTL(SG_GET_LOW_DMA)
-COMPATIBLE_IOCTL(SG_SET_FORCE_PACK_ID)
-COMPATIBLE_IOCTL(SG_GET_PACK_ID)
-COMPATIBLE_IOCTL(SG_GET_NUM_WAITING)
-COMPATIBLE_IOCTL(SG_SET_DEBUG)
-COMPATIBLE_IOCTL(SG_GET_SG_TABLESIZE)
-COMPATIBLE_IOCTL(SG_GET_COMMAND_Q)
-COMPATIBLE_IOCTL(SG_SET_COMMAND_Q)
-COMPATIBLE_IOCTL(SG_GET_VERSION_NUM)
-COMPATIBLE_IOCTL(SG_NEXT_CMD_LEN)
-COMPATIBLE_IOCTL(SG_SCSI_RESET)
-COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE)
-COMPATIBLE_IOCTL(SG_SET_KEEP_ORPHAN)
-COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN)
-#endif
-};
-
-/*
- * Convert common ioctl arguments based on their command number
- *
- * Please do not add any code in here. Instead, implement
- * a compat_ioctl operation in the place that handle? the
- * ioctl for the native case.
- */
-static long do_ioctl_trans(unsigned int cmd,
-		 unsigned long arg, struct file *file)
-{
-	return -ENOIOCTLCMD;
-}
-
-static int compat_ioctl_check_table(unsigned int xcmd)
-{
-#ifdef CONFIG_BLOCK
-	int i;
-	const int max = ARRAY_SIZE(ioctl_pointer) - 1;
-
-	BUILD_BUG_ON(max >= (1 << 16));
-
-	/* guess initial offset into table, assuming a
-	   normalized distribution */
-	i = ((xcmd >> 16) * max) >> 16;
-
-	/* do linear search up first, until greater or equal */
-	while (ioctl_pointer[i] < xcmd && i < max)
-		i++;
-
-	/* then do linear search down */
-	while (ioctl_pointer[i] > xcmd && i > 0)
-		i--;
-
-	return ioctl_pointer[i] == xcmd;
-#else
-	return 0;
-#endif
-}
-
 COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
 		       compat_ulong_t, arg32)
 {
@@ -216,19 +118,9 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned
int, cmd,
 				goto out_fput;
 		}
 
-		if (!f.file->f_op->unlocked_ioctl)
-			goto do_ioctl;
-		break;
-	}
-
-	if (compat_ioctl_check_table(XFORM(cmd)))
-		goto found_handler;
-
-	error = do_ioctl_trans(cmd, arg, f.file);
-	if (error == -ENOIOCTLCMD)
 		error = -ENOTTY;
-
-	goto out_fput;
+		goto out_fput;
+	}
 
  found_handler:
 	arg = (unsigned long)compat_ptr(arg);
@@ -239,23 +131,3 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned
int, cmd,
  out:
 	return error;
 }
-
-static int __init init_sys32_ioctl_cmp(const void *p, const void *q)
-{
-	unsigned int a, b;
-	a = *(unsigned int *)p;
-	b = *(unsigned int *)q;
-	if (a > b)
-		return 1;
-	if (a < b)
-		return -1;
-	return 0;
-}
-
-static int __init init_sys32_ioctl(void)
-{
-	sort(ioctl_pointer, ARRAY_SIZE(ioctl_pointer), sizeof(*ioctl_pointer),
-		init_sys32_ioctl_cmp, NULL);
-	return 0;
-}
-__initcall(init_sys32_ioctl);
-- 
2.20.0

On Wed, Dec 11, 2019 at 09:42:49PM +0100, Arnd Bergmann
wrote:
> Each driver calling scsi_ioctl() gets an equivalent compat_ioctl()
> handler that implements the same commands by calling scsi_compat_ioctl().
> 
> The scsi_cmd_ioctl() and scsi_cmd_blk_ioctl() functions are compatible
> at this point, so any driver that calls those can do so for both native
> and compat mode, with the argument passed through compat_ptr().
> 
> With this, we can remove the entries from fs/compat_ioctl.c.  The new
> code is larger, but should be easier to maintain and keep updated with
> newly added commands.
> 
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> ---
>  drivers/block/virtio_blk.c |   3 +
>  drivers/scsi/ch.c          |   9 ++-
>  drivers/scsi/sd.c          |  50 ++++++--------
>  drivers/scsi/sg.c          |  44 ++++++++-----
>  drivers/scsi/sr.c          |  57 ++++++++++++++--
>  drivers/scsi/st.c          |  51 ++++++++------
>  fs/compat_ioctl.c          | 132 +------------------------------------
>  7 files changed, 142 insertions(+), 204 deletions(-)
> 
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 7ffd719d89de..fbbf18ac1d5d 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -405,6 +405,9 @@ static int virtblk_getgeo(struct block_device *bd,
struct hd_geometry *geo)
>  
>  static const struct block_device_operations virtblk_fops = {
>  	.ioctl  = virtblk_ioctl,
> +#ifdef CONFIG_COMPAT
> +	.compat_ioctl = blkdev_compat_ptr_ioctl,
> +#endif
>  	.owner  = THIS_MODULE,
>  	.getgeo = virtblk_getgeo,
>  };
Hmm - is virtio blk lumped in with scsi things intentionally?

-- 
MST

On Wed, Dec 11, 2019 at 09:42:49PM +0100, Arnd Bergmann
wrote:
> Each driver calling scsi_ioctl() gets an equivalent compat_ioctl()
> handler that implements the same commands by calling scsi_compat_ioctl().
> 
> The scsi_cmd_ioctl() and scsi_cmd_blk_ioctl() functions are compatible
> at this point, so any driver that calls those can do so for both native
> and compat mode, with the argument passed through compat_ptr().
> 
> With this, we can remove the entries from fs/compat_ioctl.c.  The new
> code is larger, but should be easier to maintain and keep updated with
> newly added commands.
> 
> Signed-off-by: Arnd Bergmann <arnd at arndb.de>
> ---
>  drivers/block/virtio_blk.c |   3 +
>  drivers/scsi/ch.c          |   9 ++-
>  drivers/scsi/sd.c          |  50 ++++++--------
>  drivers/scsi/sg.c          |  44 ++++++++-----
>  drivers/scsi/sr.c          |  57 ++++++++++++++--
>  drivers/scsi/st.c          |  51 ++++++++------
>  fs/compat_ioctl.c          | 132 +------------------------------------
>  7 files changed, 142 insertions(+), 204 deletions(-)
> 
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index 7ffd719d89de..fbbf18ac1d5d 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -405,6 +405,9 @@ static int virtblk_getgeo(struct block_device *bd,
struct hd_geometry *geo)
>  
>  static const struct block_device_operations virtblk_fops = {
>  	.ioctl  = virtblk_ioctl,
> +#ifdef CONFIG_COMPAT
> +	.compat_ioctl = blkdev_compat_ptr_ioctl,
> +#endif
>  	.owner  = THIS_MODULE,
>  	.getgeo = virtblk_getgeo,
>  };

virtio part:

Acked-by: Michael S. Tsirkin <mst at redhat.com>
> diff --git a/drivers/scsi/ch.c b/drivers/scsi/ch.c
> index 76751d6c7f0d..ed5f4a6ae270 100644
> --- a/drivers/scsi/ch.c
> +++ b/drivers/scsi/ch.c
> @@ -872,6 +872,10 @@ static long ch_ioctl_compat(struct file * file,
>  			    unsigned int cmd, unsigned long arg)
>  {
>  	scsi_changer *ch = file->private_data;
> +	int retval = scsi_ioctl_block_when_processing_errors(ch->device, cmd,
> +							file->f_flags & O_NDELAY);
> +	if (retval)
> +		return retval;
>  
>  	switch (cmd) {
>  	case CHIOGPARAMS:
> @@ -883,7 +887,7 @@ static long ch_ioctl_compat(struct file * file,
>  	case CHIOINITELEM:
>  	case CHIOSVOLTAG:
>  		/* compatible */
> -		return ch_ioctl(file, cmd, arg);
> +		return ch_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
>  	case CHIOGSTATUS32:
>  	{
>  		struct changer_element_status32 ces32;
> @@ -898,8 +902,7 @@ static long ch_ioctl_compat(struct file * file,
>  		return ch_gstatus(ch, ces32.ces_type, data);
>  	}
>  	default:
> -		// return scsi_ioctl_compat(ch->device, cmd, (void*)arg);
> -		return -ENOIOCTLCMD;
> +		return scsi_compat_ioctl(ch->device, cmd, compat_ptr(arg));
>  
>  	}
>  }
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index cea625906440..5afb0046b12a 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1465,13 +1465,12 @@ static int sd_getgeo(struct block_device *bdev,
struct hd_geometry *geo)
>   *	Note: most ioctls are forward onto the block subsystem or further
>   *	down in the scsi subsystem.
>   **/
> -static int sd_ioctl(struct block_device *bdev, fmode_t mode,
> -		    unsigned int cmd, unsigned long arg)
> +static int sd_ioctl_common(struct block_device *bdev, fmode_t mode,
> +			   unsigned int cmd, void __user *p)
>  {
>  	struct gendisk *disk = bdev->bd_disk;
>  	struct scsi_disk *sdkp = scsi_disk(disk);
>  	struct scsi_device *sdp = sdkp->device;
> -	void __user *p = (void __user *)arg;
>  	int error;
>      
>  	SCSI_LOG_IOCTL(1, sd_printk(KERN_INFO, sdkp, "sd_ioctl: disk=%s,
"
> @@ -1507,9 +1506,6 @@ static int sd_ioctl(struct block_device *bdev,
fmode_t mode,
>  			break;
>  		default:
>  			error = scsi_cmd_blk_ioctl(bdev, mode, cmd, p);
> -			if (error != -ENOTTY)
> -				break;
> -			error = scsi_ioctl(sdp, cmd, p);
>  			break;
>  	}
>  out:
> @@ -1691,39 +1687,31 @@ static void sd_rescan(struct device *dev)
>  	revalidate_disk(sdkp->disk);
>  }
>  
> +static int sd_ioctl(struct block_device *bdev, fmode_t mode,
> +		    unsigned int cmd, unsigned long arg)
> +{
> +	void __user *p = (void __user *)arg;
> +	int ret;
> +
> +	ret = sd_ioctl_common(bdev, mode, cmd, p);
> +	if (ret != -ENOTTY)
> +		return ret;
> +
> +	return scsi_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p);
> +}
>  
>  #ifdef CONFIG_COMPAT
> -/* 
> - * This gets directly called from VFS. When the ioctl 
> - * is not recognized we go back to the other translation paths. 
> - */
>  static int sd_compat_ioctl(struct block_device *bdev, fmode_t mode,
>  			   unsigned int cmd, unsigned long arg)
>  {
> -	struct gendisk *disk = bdev->bd_disk;
> -	struct scsi_disk *sdkp = scsi_disk(disk);
> -	struct scsi_device *sdev = sdkp->device;
>  	void __user *p = compat_ptr(arg);
> -	int error;
> -
> -	error = scsi_verify_blk_ioctl(bdev, cmd);
> -	if (error < 0)
> -		return error;
> +	int ret;
>  
> -	error = scsi_ioctl_block_when_processing_errors(sdev, cmd,
> -			(mode & FMODE_NDELAY) != 0);
> -	if (error)
> -		return error;
> +	ret = sd_ioctl_common(bdev, mode, cmd, p);
> +	if (ret != -ENOTTY)
> +		return ret;
>  
> -	if (is_sed_ioctl(cmd))
> -		return sed_ioctl(sdkp->opal_dev, cmd, p);
> -	       
> -	/* 
> -	 * Let the static ioctl translation table take care of it.
> -	 */
> -	if (!sdev->host->hostt->compat_ioctl)
> -		return -ENOIOCTLCMD; 
> -	return sdev->host->hostt->compat_ioctl(sdev, cmd, p);
> +	return scsi_compat_ioctl(scsi_disk(bdev->bd_disk)->device, cmd, p);
>  }
>  #endif
>  
> diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
> index 985546aac236..08efcee7a34d 100644
> --- a/drivers/scsi/sg.c
> +++ b/drivers/scsi/sg.c
> @@ -910,19 +910,14 @@ static int put_compat_request_table(struct
compat_sg_req_info __user *o,
>  #endif
>  
>  static long
> -sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
> +sg_ioctl_common(struct file *filp, Sg_device *sdp, Sg_fd *sfp,
> +		unsigned int cmd_in, void __user *p)
>  {
> -	void __user *p = (void __user *)arg;
>  	int __user *ip = p;
>  	int result, val, read_only;
> -	Sg_device *sdp;
> -	Sg_fd *sfp;
>  	Sg_request *srp;
>  	unsigned long iflags;
>  
> -	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp =
sfp->parentdp)))
> -		return -ENXIO;
> -
>  	SCSI_LOG_TIMEOUT(3, sg_printk(KERN_INFO, sdp,
>  				   "sg_ioctl: cmd=0x%x\n", (int) cmd_in));
>  	read_only = (O_RDWR != (filp->f_flags & O_ACCMODE));
> @@ -1145,29 +1140,44 @@ sg_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
>  			cmd_in, filp->f_flags & O_NDELAY);
>  	if (result)
>  		return result;
> +
> +	return -ENOIOCTLCMD;
> +}
> +
> +static long
> +sg_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
> +{
> +	void __user *p = (void __user *)arg;
> +	Sg_device *sdp;
> +	Sg_fd *sfp;
> +	int ret;
> +
> +	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp =
sfp->parentdp)))
> +		return -ENXIO;
> +
> +	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
> +	if (ret != -ENOIOCTLCMD)
> +		return ret;
> +
>  	return scsi_ioctl(sdp->device, cmd_in, p);
>  }
>  
>  #ifdef CONFIG_COMPAT
>  static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in,
unsigned long arg)
>  {
> +	void __user *p = compat_ptr(arg);
>  	Sg_device *sdp;
>  	Sg_fd *sfp;
> -	struct scsi_device *sdev;
> +	int ret;
>  
>  	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp =
sfp->parentdp)))
>  		return -ENXIO;
>  
> -	sdev = sdp->device;
> -	if (sdev->host->hostt->compat_ioctl) { 
> -		int ret;
> -
> -		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void
__user *)arg);
> -
> +	ret = sg_ioctl_common(filp, sdp, sfp, cmd_in, p);
> +	if (ret != -ENOIOCTLCMD)
>  		return ret;
> -	}
> -	
> -	return -ENOIOCTLCMD;
> +
> +	return scsi_compat_ioctl(sdp->device, cmd_in, p);
>  }
>  #endif
>  
> diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
> index 4664fdf75c0f..6033a886c42c 100644
> --- a/drivers/scsi/sr.c
> +++ b/drivers/scsi/sr.c
> @@ -38,6 +38,7 @@
>  #include <linux/kernel.h>
>  #include <linux/mm.h>
>  #include <linux/bio.h>
> +#include <linux/compat.h>
>  #include <linux/string.h>
>  #include <linux/errno.h>
>  #include <linux/cdrom.h>
> @@ -598,6 +599,55 @@ static int sr_block_ioctl(struct block_device *bdev,
fmode_t mode, unsigned cmd,
>  	return ret;
>  }
>  
> +#ifdef CONFIG_COMPAT
> +static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode,
unsigned cmd,
> +			  unsigned long arg)
> +{
> +	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
> +	struct scsi_device *sdev = cd->device;
> +	void __user *argp = compat_ptr(arg);
> +	int ret;
> +
> +	mutex_lock(&sr_mutex);
> +
> +	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
> +			(mode & FMODE_NDELAY) != 0);
> +	if (ret)
> +		goto out;
> +
> +	scsi_autopm_get_device(sdev);
> +
> +	/*
> +	 * Send SCSI addressing ioctls directly to mid level, send other
> +	 * ioctls to cdrom/block level.
> +	 */
> +	switch (cmd) {
> +	case SCSI_IOCTL_GET_IDLUN:
> +	case SCSI_IOCTL_GET_BUS_NUMBER:
> +		ret = scsi_compat_ioctl(sdev, cmd, argp);
> +		goto put;
> +	}
> +
> +	/*
> +	 * CDROM ioctls are handled in the block layer, but
> +	 * do the scsi blk ioctls here.
> +	 */
> +	ret = scsi_cmd_blk_ioctl(bdev, mode, cmd, argp);
> +	if (ret != -ENOTTY)
> +		return ret;
> +
> +	ret = scsi_compat_ioctl(sdev, cmd, argp);
> +
> +put:
> +	scsi_autopm_put_device(sdev);
> +
> +out:
> +	mutex_unlock(&sr_mutex);
> +	return ret;
> +
> +}
> +#endif
> +
>  static unsigned int sr_block_check_events(struct gendisk *disk,
>  					  unsigned int clearing)
>  {
> @@ -641,12 +691,11 @@ static const struct block_device_operations sr_bdops
>  	.open		= sr_block_open,
>  	.release	= sr_block_release,
>  	.ioctl		= sr_block_ioctl,
> +#ifdef CONFIG_COMPAT
> +	.ioctl		= sr_block_compat_ioctl,
> +#endif
>  	.check_events	= sr_block_check_events,
>  	.revalidate_disk = sr_block_revalidate_disk,
> -	/* 
> -	 * No compat_ioctl for now because sr_block_ioctl never
> -	 * seems to pass arbitrary ioctls down to host drivers.
> -	 */
>  };
>  
>  static int sr_open(struct cdrom_device_info *cdi, int purpose)
> diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
> index 9e3fff2de83e..393f3019ccac 100644
> --- a/drivers/scsi/st.c
> +++ b/drivers/scsi/st.c
> @@ -3501,7 +3501,7 @@ static int partition_tape(struct scsi_tape *STp, int
size)
>  
>  
>  /* The ioctl command */
> -static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long
arg)
> +static long st_ioctl_common(struct file *file, unsigned int cmd_in, void
__user *p)
>  {
>  	int i, cmd_nr, cmd_type, bt;
>  	int retval = 0;
> @@ -3509,7 +3509,6 @@ static long st_ioctl(struct file *file, unsigned int
cmd_in, unsigned long arg)
>  	struct scsi_tape *STp = file->private_data;
>  	struct st_modedef *STm;
>  	struct st_partstat *STps;
> -	void __user *p = (void __user *)arg;
>  
>  	if (mutex_lock_interruptible(&STp->lock))
>  		return -ERESTARTSYS;
> @@ -3824,9 +3823,19 @@ static long st_ioctl(struct file *file, unsigned int
cmd_in, unsigned long arg)
>  	}
>  	mutex_unlock(&STp->lock);
>  	switch (cmd_in) {
> +		case SCSI_IOCTL_STOP_UNIT:
> +			/* unload */
> +			retval = scsi_ioctl(STp->device, cmd_in, p);
> +			if (!retval) {
> +				STp->rew_at_close = 0;
> +				STp->ready = ST_NO_TAPE;
> +			}
> +			return retval;
> +
>  		case SCSI_IOCTL_GET_IDLUN:
>  		case SCSI_IOCTL_GET_BUS_NUMBER:
>  			break;
> +
>  		default:
>  			if ((cmd_in == SG_IO ||
>  			     cmd_in == SCSI_IOCTL_SEND_COMMAND ||
> @@ -3840,42 +3849,46 @@ static long st_ioctl(struct file *file, unsigned
int cmd_in, unsigned long arg)
>  				return i;
>  			break;
>  	}
> -	retval = scsi_ioctl(STp->device, cmd_in, p);
> -	if (!retval && cmd_in == SCSI_IOCTL_STOP_UNIT) { /* unload */
> -		STp->rew_at_close = 0;
> -		STp->ready = ST_NO_TAPE;
> -	}
> -	return retval;
> +	return -ENOTTY;
>  
>   out:
>  	mutex_unlock(&STp->lock);
>  	return retval;
>  }
>  
> +static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long
arg)
> +{
> +	void __user *p = (void __user *)arg;
> +	struct scsi_tape *STp = file->private_data;
> +	int ret;
> +
> +	ret = st_ioctl_common(file, cmd_in, p);
> +	if (ret != -ENOTTY)
> +		return ret;
> +
> +	return scsi_ioctl(STp->device, cmd_in, p);
> +}
> +
>  #ifdef CONFIG_COMPAT
>  static long st_compat_ioctl(struct file *file, unsigned int cmd_in,
unsigned long arg)
>  {
>  	void __user *p = compat_ptr(arg);
>  	struct scsi_tape *STp = file->private_data;
> -	struct scsi_device *sdev = STp->device;
> -	int ret = -ENOIOCTLCMD;
> +	int ret;
>  
>  	/* argument conversion is handled using put_user_mtpos/put_user_mtget */
>  	switch (cmd_in) {
> -	case MTIOCTOP:
> -		return st_ioctl(file, MTIOCTOP, (unsigned long)p);
>  	case MTIOCPOS32:
> -		return st_ioctl(file, MTIOCPOS, (unsigned long)p);
> +		return st_ioctl_common(file, MTIOCPOS, p);
>  	case MTIOCGET32:
> -		return st_ioctl(file, MTIOCGET, (unsigned long)p);
> +		return st_ioctl_common(file, MTIOCGET, p);
>  	}
>  
> -	if (sdev->host->hostt->compat_ioctl) { 
> +	ret = st_ioctl_common(file, cmd_in, p);
> +	if (ret != -ENOTTY)
> +		return ret;
>  
> -		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void
__user *)arg);
> -
> -	}
> -	return ret;
> +	return scsi_compat_ioctl(STp->device, cmd_in, p);
>  }
>  #endif
>  
> diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
> index 358ea2ecf36b..ab4471f469e6 100644
> --- a/fs/compat_ioctl.c
> +++ b/fs/compat_ioctl.c
> @@ -36,109 +36,11 @@
>  
>  #include "internal.h"
>  
> -#ifdef CONFIG_BLOCK
> -#include <linux/cdrom.h>
> -#include <linux/fd.h>
> -#include <scsi/scsi.h>
> -#include <scsi/scsi_ioctl.h>
> -#include <scsi/sg.h>
> -#endif
> -
>  #include <linux/uaccess.h>
>  #include <linux/watchdog.h>
>  
>  #include <linux/hiddev.h>
>  
> -
> -#include <linux/sort.h>
> -
> -/*
> - * simple reversible transform to make our table more evenly
> - * distributed after sorting.
> - */
> -#define XFORM(i) (((i) ^ ((i) << 27) ^ ((i) << 17)) &
0xffffffff)
> -
> -#define COMPATIBLE_IOCTL(cmd) XFORM((u32)cmd),
> -static unsigned int ioctl_pointer[] = {
> -#ifdef CONFIG_BLOCK
> -/* Big S */
> -COMPATIBLE_IOCTL(SCSI_IOCTL_GET_IDLUN)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_DOORLOCK)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_DOORUNLOCK)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_TEST_UNIT_READY)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_GET_BUS_NUMBER)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_SEND_COMMAND)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_PROBE_HOST)
> -COMPATIBLE_IOCTL(SCSI_IOCTL_GET_PCI)
> -#endif
> -#ifdef CONFIG_BLOCK
> -/* SG stuff */
> -COMPATIBLE_IOCTL(SG_IO)
> -COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE)
> -COMPATIBLE_IOCTL(SG_SET_TIMEOUT)
> -COMPATIBLE_IOCTL(SG_GET_TIMEOUT)
> -COMPATIBLE_IOCTL(SG_EMULATED_HOST)
> -COMPATIBLE_IOCTL(SG_GET_TRANSFORM)
> -COMPATIBLE_IOCTL(SG_SET_RESERVED_SIZE)
> -COMPATIBLE_IOCTL(SG_GET_RESERVED_SIZE)
> -COMPATIBLE_IOCTL(SG_GET_SCSI_ID)
> -COMPATIBLE_IOCTL(SG_SET_FORCE_LOW_DMA)
> -COMPATIBLE_IOCTL(SG_GET_LOW_DMA)
> -COMPATIBLE_IOCTL(SG_SET_FORCE_PACK_ID)
> -COMPATIBLE_IOCTL(SG_GET_PACK_ID)
> -COMPATIBLE_IOCTL(SG_GET_NUM_WAITING)
> -COMPATIBLE_IOCTL(SG_SET_DEBUG)
> -COMPATIBLE_IOCTL(SG_GET_SG_TABLESIZE)
> -COMPATIBLE_IOCTL(SG_GET_COMMAND_Q)
> -COMPATIBLE_IOCTL(SG_SET_COMMAND_Q)
> -COMPATIBLE_IOCTL(SG_GET_VERSION_NUM)
> -COMPATIBLE_IOCTL(SG_NEXT_CMD_LEN)
> -COMPATIBLE_IOCTL(SG_SCSI_RESET)
> -COMPATIBLE_IOCTL(SG_GET_REQUEST_TABLE)
> -COMPATIBLE_IOCTL(SG_SET_KEEP_ORPHAN)
> -COMPATIBLE_IOCTL(SG_GET_KEEP_ORPHAN)
> -#endif
> -};
> -
> -/*
> - * Convert common ioctl arguments based on their command number
> - *
> - * Please do not add any code in here. Instead, implement
> - * a compat_ioctl operation in the place that handle? the
> - * ioctl for the native case.
> - */
> -static long do_ioctl_trans(unsigned int cmd,
> -		 unsigned long arg, struct file *file)
> -{
> -	return -ENOIOCTLCMD;
> -}
> -
> -static int compat_ioctl_check_table(unsigned int xcmd)
> -{
> -#ifdef CONFIG_BLOCK
> -	int i;
> -	const int max = ARRAY_SIZE(ioctl_pointer) - 1;
> -
> -	BUILD_BUG_ON(max >= (1 << 16));
> -
> -	/* guess initial offset into table, assuming a
> -	   normalized distribution */
> -	i = ((xcmd >> 16) * max) >> 16;
> -
> -	/* do linear search up first, until greater or equal */
> -	while (ioctl_pointer[i] < xcmd && i < max)
> -		i++;
> -
> -	/* then do linear search down */
> -	while (ioctl_pointer[i] > xcmd && i > 0)
> -		i--;
> -
> -	return ioctl_pointer[i] == xcmd;
> -#else
> -	return 0;
> -#endif
> -}
> -
>  COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd, unsigned int, cmd,
>  		       compat_ulong_t, arg32)
>  {
> @@ -216,19 +118,9 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd,
unsigned int, cmd,
>  				goto out_fput;
>  		}
>  
> -		if (!f.file->f_op->unlocked_ioctl)
> -			goto do_ioctl;
> -		break;
> -	}
> -
> -	if (compat_ioctl_check_table(XFORM(cmd)))
> -		goto found_handler;
> -
> -	error = do_ioctl_trans(cmd, arg, f.file);
> -	if (error == -ENOIOCTLCMD)
>  		error = -ENOTTY;
> -
> -	goto out_fput;
> +		goto out_fput;
> +	}
>  
>   found_handler:
>  	arg = (unsigned long)compat_ptr(arg);
> @@ -239,23 +131,3 @@ COMPAT_SYSCALL_DEFINE3(ioctl, unsigned int, fd,
unsigned int, cmd,
>   out:
>  	return error;
>  }
> -
> -static int __init init_sys32_ioctl_cmp(const void *p, const void *q)
> -{
> -	unsigned int a, b;
> -	a = *(unsigned int *)p;
> -	b = *(unsigned int *)q;
> -	if (a > b)
> -		return 1;
> -	if (a < b)
> -		return -1;
> -	return 0;
> -}
> -
> -static int __init init_sys32_ioctl(void)
> -{
> -	sort(ioctl_pointer, ARRAY_SIZE(ioctl_pointer), sizeof(*ioctl_pointer),
> -		init_sys32_ioctl_cmp, NULL);
> -	return 0;
> -}
> -__initcall(init_sys32_ioctl);
> -- 
> 2.20.0