block ioctl cleanups v2

block ioctl cleanups v2

[Christoph Hellwig]

Hi Jens,

this series has a bunch of cleanups for the block layer ioctl code.

Changes since v1:
 - drop the patch to return the correct error for unknown ioctls in mtip
 - add back an empty line in rbd
 - various spelling fixes

[PATCH 01/10] mtd_blkdevs: don't override BLKFLSBUF

[Christoph Hellwig]

BLKFLSBUF is not supposed to actually send a flush command to the device,
but to tear down buffer cache structures.  Remove the mtd_blkdevs
implementation and just use the default semantics instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Weinberger <richard@nod.at>
---
 drivers/mtd/mtd_blkdevs.c | 28 ----------------------------
 1 file changed, 28 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 0c05f77f9b216e..fb8e12d590a13a 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -298,38 +298,10 @@ static int blktrans_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return ret;
 }
 
-static int blktrans_ioctl(struct block_device *bdev, fmode_t mode,
-			      unsigned int cmd, unsigned long arg)
-{
-	struct mtd_blktrans_dev *dev = blktrans_dev_get(bdev->bd_disk);
-	int ret = -ENXIO;
-
-	if (!dev)
-		return ret;
-
-	mutex_lock(&dev->lock);
-
-	if (!dev->mtd)
-		goto unlock;
-
-	switch (cmd) {
-	case BLKFLSBUF:
-		ret = dev->tr->flush ? dev->tr->flush(dev) : 0;
-		break;
-	default:
-		ret = -ENOTTY;
-	}
-unlock:
-	mutex_unlock(&dev->lock);
-	blktrans_dev_put(dev);
-	return ret;
-}
-
 static const struct block_device_operations mtd_block_ops = {
 	.owner		= THIS_MODULE,
 	.open		= blktrans_open,
 	.release	= blktrans_release,
-	.ioctl		= blktrans_ioctl,
 	.getgeo		= blktrans_getgeo,
 };
 
-- 
2.28.0

[PATCH 02/10] block: don't call into the driver for BLKFLSBUF

[Christoph Hellwig]

BLKFLSBUF is entirely contained in the block core, and there is no
good reason to give the driver a hook into processing it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/ioctl.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index 3fbc382eb926d4..c6d8863f040945 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -369,15 +369,8 @@ static inline int is_unrecognized_ioctl(int ret)
 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
 		unsigned cmd, unsigned long arg)
 {
-	int ret;
-
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
-
-	ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
-	if (!is_unrecognized_ioctl(ret))
-		return ret;
-
 	fsync_bdev(bdev);
 	invalidate_bdev(bdev);
 	return 0;
-- 
2.28.0

[PATCH 03/10] block: add a new set_read_only method

[Christoph Hellwig]

Add a new method to allow for driver-specific processing when setting or
clearing the block device read-only state.  This allows to replace the
cumbersome and error-prone override of the whole ioctl implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/ioctl.c          | 5 +++++
 include/linux/blkdev.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/block/ioctl.c b/block/ioctl.c
index c6d8863f040945..a6fa16b9770593 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -389,6 +389,11 @@ static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 		return ret;
 	if (get_user(n, (int __user *)arg))
 		return -EFAULT;
+	if (bdev->bd_disk->fops->set_read_only) {
+		ret = bdev->bd_disk->fops->set_read_only(bdev, n);
+		if (ret)
+			return ret;
+	}
 	set_device_ro(bdev, n);
 	return 0;
 }
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 639cae2c158b59..5c1ba8a8d2bc7e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1850,6 +1850,7 @@ struct block_device_operations {
 	void (*unlock_native_capacity) (struct gendisk *);
 	int (*revalidate_disk) (struct gendisk *);
 	int (*getgeo)(struct block_device *, struct hd_geometry *);
+	int (*set_read_only)(struct block_device *bdev, bool ro);
 	/* this callback is with swap_lock and sometimes page table lock held */
 	void (*swap_slot_free_notify) (struct block_device *, unsigned long);
 	int (*report_zones)(struct gendisk *, sector_t sector,
-- 
2.28.0

[PATCH 04/10] rbd: implement ->set_read_only to hook into BLKROSET processing

[Christoph Hellwig]

Implement the ->set_read_only method instead of parsing the actual
ioctl command.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ilya Dryomov <idryomov@gmail.com>
---
 drivers/block/rbd.c | 40 ++++------------------------------------
 1 file changed, 4 insertions(+), 36 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index f84128abade319..671733e459cf47 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -692,12 +692,9 @@ static void rbd_release(struct gendisk *disk, fmode_t mode)
 	put_device(&rbd_dev->dev);
 }
 
-static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
+static int rbd_set_read_only(struct block_device *bdev, bool ro)
 {
-	int ro;
-
-	if (get_user(ro, (int __user *)arg))
-		return -EFAULT;
+	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
 
 	/*
 	 * Both images mapped read-only and snapshots can't be marked
@@ -710,43 +707,14 @@ static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
 		rbd_assert(!rbd_is_snap(rbd_dev));
 	}
 
-	/* Let blkdev_roset() handle it */
-	return -ENOTTY;
-}
-
-static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
-			unsigned int cmd, unsigned long arg)
-{
-	struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
-	int ret;
-
-	switch (cmd) {
-	case BLKROSET:
-		ret = rbd_ioctl_set_ro(rbd_dev, arg);
-		break;
-	default:
-		ret = -ENOTTY;
-	}
-
-	return ret;
-}
-
-#ifdef CONFIG_COMPAT
-static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
-				unsigned int cmd, unsigned long arg)
-{
-	return rbd_ioctl(bdev, mode, cmd, arg);
+	return 0;
 }
-#endif /* CONFIG_COMPAT */
 
 static const struct block_device_operations rbd_bd_ops = {
 	.owner			= THIS_MODULE,
 	.open			= rbd_open,
 	.release		= rbd_release,
-	.ioctl			= rbd_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl		= rbd_compat_ioctl,
-#endif
+	.set_read_only		= rbd_set_read_only,
 };
 
 /*
-- 
2.28.0

[PATCH 05/10] md: implement ->set_read_only to hook into BLKROSET processing

[Christoph Hellwig]

Implement the ->set_read_only method instead of parsing the actual
ioctl command.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/md.c | 62 ++++++++++++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 31 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 98bac4f304ae26..96d31336ad43fe 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7480,7 +7480,6 @@ static inline bool md_ioctl_valid(unsigned int cmd)
 {
 	switch (cmd) {
 	case ADD_NEW_DISK:
-	case BLKROSET:
 	case GET_ARRAY_INFO:
 	case GET_BITMAP_FILE:
 	case GET_DISK_INFO:
@@ -7507,7 +7506,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
 	int err = 0;
 	void __user *argp = (void __user *)arg;
 	struct mddev *mddev = NULL;
-	int ro;
 	bool did_set_md_closing = false;
 
 	if (!md_ioctl_valid(cmd))
@@ -7687,35 +7685,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
 			goto unlock;
 		}
 		break;
-
-	case BLKROSET:
-		if (get_user(ro, (int __user *)(arg))) {
-			err = -EFAULT;
-			goto unlock;
-		}
-		err = -EINVAL;
-
-		/* if the bdev is going readonly the value of mddev->ro
-		 * does not matter, no writes are coming
-		 */
-		if (ro)
-			goto unlock;
-
-		/* are we are already prepared for writes? */
-		if (mddev->ro != 1)
-			goto unlock;
-
-		/* transitioning to readauto need only happen for
-		 * arrays that call md_write_start
-		 */
-		if (mddev->pers) {
-			err = restart_array(mddev);
-			if (err == 0) {
-				mddev->ro = 2;
-				set_disk_ro(mddev->gendisk, 0);
-			}
-		}
-		goto unlock;
 	}
 
 	/*
@@ -7809,6 +7778,36 @@ static int md_compat_ioctl(struct block_device *bdev, fmode_t mode,
 }
 #endif /* CONFIG_COMPAT */
 
+static int md_set_read_only(struct block_device *bdev, bool ro)
+{
+	struct mddev *mddev = bdev->bd_disk->private_data;
+	int err;
+
+	err = mddev_lock(mddev);
+	if (err)
+		return err;
+
+	if (!mddev->raid_disks && !mddev->external) {
+		err = -ENODEV;
+		goto out_unlock;
+	}
+
+	/*
+	 * Transitioning to read-auto need only happen for arrays that call
+	 * md_write_start and which are not ready for writes yet.
+	 */
+	if (!ro && mddev->ro == 1 && mddev->pers) {
+		err = restart_array(mddev);
+		if (err)
+			goto out_unlock;
+		mddev->ro = 2;
+	}
+
+out_unlock:
+	mddev_unlock(mddev);
+	return err;
+}
+
 static int md_open(struct block_device *bdev, fmode_t mode)
 {
 	/*
@@ -7886,6 +7885,7 @@ const struct block_device_operations md_fops =
 #endif
 	.getgeo		= md_getgeo,
 	.check_events	= md_check_events,
+	.set_read_only	= md_set_read_only,
 };
 
 static int md_thread(void *arg)
-- 
2.28.0

[PATCH 06/10] dasd: implement ->set_read_only to hook into BLKROSET processing

[Christoph Hellwig]

Implement the ->set_read_only method instead of parsing the actual
ioctl command.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/s390/block/dasd.c       |  1 +
 drivers/s390/block/dasd_int.h   |  3 ++-
 drivers/s390/block/dasd_ioctl.c | 27 +++++++++------------------
 3 files changed, 12 insertions(+), 19 deletions(-)

diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index eb17fea8075c6f..db24e04ee9781e 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -3394,6 +3394,7 @@ dasd_device_operations = {
 	.ioctl		= dasd_ioctl,
 	.compat_ioctl	= dasd_ioctl,
 	.getgeo		= dasd_getgeo,
+	.set_read_only	= dasd_set_read_only,
 };
 
 /*******************************************************************************
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index fa552f9f166671..c59a0d63b506e6 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -844,7 +844,8 @@ int dasd_scan_partitions(struct dasd_block *);
 void dasd_destroy_partitions(struct dasd_block *);
 
 /* externals in dasd_ioctl.c */
-int  dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
+int dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
+int dasd_set_read_only(struct block_device *bdev, bool ro);
 
 /* externals in dasd_proc.c */
 int dasd_proc_init(void);
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index cb6427fb9f3d16..3359559517bfcf 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -532,28 +532,22 @@ static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
 /*
  * Set read only
  */
-static int
-dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
+int dasd_set_read_only(struct block_device *bdev, bool ro)
 {
 	struct dasd_device *base;
-	int intval, rc;
+	int rc;
 
-	if (!capable(CAP_SYS_ADMIN))
-		return -EACCES;
+	/* do not manipulate hardware state for partitions */
 	if (bdev_is_partition(bdev))
-		// ro setting is not allowed for partitions
-		return -EINVAL;
-	if (get_user(intval, (int __user *)argp))
-		return -EFAULT;
+		return 0;
+
 	base = dasd_device_from_gendisk(bdev->bd_disk);
 	if (!base)
 		return -ENODEV;
-	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
-		dasd_put_device(base);
-		return -EROFS;
-	}
-	set_disk_ro(bdev->bd_disk, intval);
-	rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
+	if (!ro && test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
+		rc = -EROFS;
+	else
+		rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, ro);
 	dasd_put_device(base);
 	return rc;
 }
@@ -633,9 +627,6 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
 	case BIODASDPRRST:
 		rc = dasd_ioctl_reset_profile(block);
 		break;
-	case BLKROSET:
-		rc = dasd_ioctl_set_ro(bdev, argp);
-		break;
 	case DASDAPIVER:
 		rc = dasd_ioctl_api_version(argp);
 		break;
-- 
2.28.0

[PATCH 07/10] block: don't call into the driver for BLKROSET

[Christoph Hellwig]

Now that all drivers that want to hook into setting or clearing the
read-only flag use the set_read_only method, this code can be removed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/ioctl.c | 23 -----------------------
 1 file changed, 23 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index a6fa16b9770593..96cb4544736468 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -346,26 +346,6 @@ static int blkdev_pr_clear(struct block_device *bdev,
 	return ops->pr_clear(bdev, c.key);
 }
 
-/*
- * Is it an unrecognized ioctl? The correct returns are either
- * ENOTTY (final) or ENOIOCTLCMD ("I don't know this one, try a
- * fallback"). ENOIOCTLCMD gets turned into ENOTTY by the ioctl
- * code before returning.
- *
- * Confused drivers sometimes return EINVAL, which is wrong. It
- * means "I understood the ioctl command, but the parameters to
- * it were wrong".
- *
- * We should aim to just fix the broken drivers, the EINVAL case
- * should go away.
- */
-static inline int is_unrecognized_ioctl(int ret)
-{
-	return	ret == -EINVAL ||
-		ret == -ENOTTY ||
-		ret == -ENOIOCTLCMD;
-}
-
 static int blkdev_flushbuf(struct block_device *bdev, fmode_t mode,
 		unsigned cmd, unsigned long arg)
 {
@@ -384,9 +364,6 @@ static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
 
-	ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
-	if (!is_unrecognized_ioctl(ret))
-		return ret;
 	if (get_user(n, (int __user *)arg))
 		return -EFAULT;
 	if (bdev->bd_disk->fops->set_read_only) {
-- 
2.28.0

[PATCH 08/10] loop: use set_disk_ro

[Christoph Hellwig]

Use set_disk_ro instead of set_device_ro to match all other block
drivers and to ensure all partitions mirror the read-only flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/loop.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index cb1191d6e945f2..3e1ea45bb315d8 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1137,7 +1137,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	if (error)
 		goto out_unlock;
 
-	set_device_ro(bdev, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);
+	set_disk_ro(lo->lo_disk, (lo->lo_flags & LO_FLAGS_READ_ONLY) != 0);
 
 	lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO;
 	lo->lo_device = bdev;
-- 
2.28.0

[PATCH 09/10] block: remove set_device_ro

[Christoph Hellwig]

Fold set_device_ro into its only remaining caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c         | 7 -------
 block/ioctl.c         | 2 +-
 include/linux/genhd.h | 1 -
 3 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 0a273211fec283..a487590b365e89 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1843,13 +1843,6 @@ static void set_disk_ro_uevent(struct gendisk *gd, int ro)
 	kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
 }
 
-void set_device_ro(struct block_device *bdev, int flag)
-{
-	bdev->bd_part->policy = flag;
-}
-
-EXPORT_SYMBOL(set_device_ro);
-
 void set_disk_ro(struct gendisk *disk, int flag)
 {
 	struct disk_part_iter piter;
diff --git a/block/ioctl.c b/block/ioctl.c
index 96cb4544736468..04255dc5f3bff3 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -371,7 +371,7 @@ static int blkdev_roset(struct block_device *bdev, fmode_t mode,
 		if (ret)
 			return ret;
 	}
-	set_device_ro(bdev, n);
+	bdev->bd_part->policy = n;
 	return 0;
 }
 
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 38f23d75701379..f232f26d7c777b 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -304,7 +304,6 @@ extern void del_gendisk(struct gendisk *gp);
 extern struct gendisk *get_gendisk(dev_t dev, int *partno);
 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 
-extern void set_device_ro(struct block_device *bdev, int flag);
 extern void set_disk_ro(struct gendisk *disk, int flag);
 
 static inline int get_disk_ro(struct gendisk *disk)
-- 
2.28.0

[PATCH 10/10] block: remove __blkdev_driver_ioctl

[Christoph Hellwig]

Just open code it in the few callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/ioctl.c               | 25 +++++--------------------
 drivers/block/pktcdvd.c     |  6 ++++--
 drivers/md/bcache/request.c |  5 +++--
 drivers/md/dm.c             |  5 ++++-
 include/linux/blkdev.h      |  2 --
 5 files changed, 16 insertions(+), 27 deletions(-)

diff --git a/block/ioctl.c b/block/ioctl.c
index 04255dc5f3bff3..6b785181344fe1 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -219,23 +219,6 @@ static int compat_put_ulong(compat_ulong_t __user *argp, compat_ulong_t val)
 }
 #endif
 
-int __blkdev_driver_ioctl(struct block_device *bdev, fmode_t mode,
-			unsigned cmd, unsigned long arg)
-{
-	struct gendisk *disk = bdev->bd_disk;
-
-	if (disk->fops->ioctl)
-		return disk->fops->ioctl(bdev, mode, cmd, arg);
-
-	return -ENOTTY;
-}
-/*
- * For the record: _GPL here is only because somebody decided to slap it
- * on the previous export.  Sheer idiocy, since it wasn't copyrightable
- * at all and could be open-coded without any exports by anybody who cares.
- */
-EXPORT_SYMBOL_GPL(__blkdev_driver_ioctl);
-
 #ifdef CONFIG_COMPAT
 /*
  * This is the equivalent of compat_ptr_ioctl(), to be used by block
@@ -594,10 +577,12 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 	}
 
 	ret = blkdev_common_ioctl(bdev, mode, cmd, arg, argp);
-	if (ret == -ENOIOCTLCMD)
-		return __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
 
-	return ret;
+	if (!bdev->bd_disk->fops->ioctl)
+		return -ENOTTY;
+	return bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
 }
 EXPORT_SYMBOL_GPL(blkdev_ioctl); /* for /dev/raw */
 
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 467dbd06b7cdb1..ef1c1f094ea4fc 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2584,9 +2584,11 @@ static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 	case CDROM_LAST_WRITTEN:
 	case CDROM_SEND_PACKET:
 	case SCSI_IOCTL_SEND_COMMAND:
-		ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
+		if (!bdev->bd_disk->fops->ioctl)
+			ret = -ENOTTY;
+		else
+			ret = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
 		break;
-
 	default:
 		pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
 		ret = -ENOTTY;
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index 21432638314562..afac8d07c1bd00 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -1230,8 +1230,9 @@ static int cached_dev_ioctl(struct bcache_device *d, fmode_t mode,
 
 	if (dc->io_disable)
 		return -EIO;
-
-	return __blkdev_driver_ioctl(dc->bdev, mode, cmd, arg);
+	if (!dc->bdev->bd_disk->fops->ioctl)
+		return -ENOTTY;
+	return dc->bdev->bd_disk->fops->ioctl(dc->bdev, mode, cmd, arg);
 }
 
 void bch_cached_dev_request_init(struct cached_dev *dc)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index c18fc25485186d..6db395c3d28be8 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -570,7 +570,10 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode,
 		}
 	}
 
-	r =  __blkdev_driver_ioctl(bdev, mode, cmd, arg);
+	if (!bdev->bd_disk->fops->ioctl)
+		r = -ENOTTY;
+	else
+		r = bdev->bd_disk->fops->ioctl(bdev, mode, cmd, arg);
 out:
 	dm_unprepare_ioctl(md, srcu_idx);
 	return r;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5c1ba8a8d2bc7e..05b346a68c2eee 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1867,8 +1867,6 @@ extern int blkdev_compat_ptr_ioctl(struct block_device *, fmode_t,
 #define blkdev_compat_ptr_ioctl NULL
 #endif
 
-extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int,
-				 unsigned long);
 extern int bdev_read_page(struct block_device *, sector_t, struct page *);
 extern int bdev_write_page(struct block_device *, sector_t, struct page *,
 						struct writeback_control *);
-- 
2.28.0

Re: [PATCH 06/10] dasd: implement ->set_read_only to hook into BLKROSET processing

[Stefan Haberland]

Christoph Hellwig <hch@lst.de> schrieb am Tue, 03. Nov 11:00:
> Implement the ->set_read_only method instead of parsing the actual
> ioctl command.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/s390/block/dasd.c       |  1 +
>  drivers/s390/block/dasd_int.h   |  3 ++-
>  drivers/s390/block/dasd_ioctl.c | 27 +++++++++------------------
>  3 files changed, 12 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
> index eb17fea8075c6f..db24e04ee9781e 100644
> --- a/drivers/s390/block/dasd.c
> +++ b/drivers/s390/block/dasd.c
> @@ -3394,6 +3394,7 @@ dasd_device_operations = {
>  	.ioctl		= dasd_ioctl,
>  	.compat_ioctl	= dasd_ioctl,
>  	.getgeo		= dasd_getgeo,
> +	.set_read_only	= dasd_set_read_only,
>  };
>  
>  /*******************************************************************************
> diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
> index fa552f9f166671..c59a0d63b506e6 100644
> --- a/drivers/s390/block/dasd_int.h
> +++ b/drivers/s390/block/dasd_int.h
> @@ -844,7 +844,8 @@ int dasd_scan_partitions(struct dasd_block *);
>  void dasd_destroy_partitions(struct dasd_block *);
>  
>  /* externals in dasd_ioctl.c */
> -int  dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
> +int dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
> +int dasd_set_read_only(struct block_device *bdev, bool ro);
>  
>  /* externals in dasd_proc.c */
>  int dasd_proc_init(void);
> diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
> index cb6427fb9f3d16..3359559517bfcf 100644
> --- a/drivers/s390/block/dasd_ioctl.c
> +++ b/drivers/s390/block/dasd_ioctl.c
> @@ -532,28 +532,22 @@ static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
>  /*
>   * Set read only
>   */
> -static int
> -dasd_ioctl_set_ro(struct block_device *bdev, void __user *argp)
> +int dasd_set_read_only(struct block_device *bdev, bool ro)
>  {
>  	struct dasd_device *base;
> -	int intval, rc;
> +	int rc;
>  
> -	if (!capable(CAP_SYS_ADMIN))
> -		return -EACCES;
> +	/* do not manipulate hardware state for partitions */
>  	if (bdev_is_partition(bdev))
> -		// ro setting is not allowed for partitions
> -		return -EINVAL;
> -	if (get_user(intval, (int __user *)argp))
> -		return -EFAULT;
> +		return 0;
> +
>  	base = dasd_device_from_gendisk(bdev->bd_disk);
>  	if (!base)
>  		return -ENODEV;
> -	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
> -		dasd_put_device(base);
> -		return -EROFS;
> -	}
> -	set_disk_ro(bdev->bd_disk, intval);


While testing this patch I just noticed that when I set a device readonly this is
not going to be passed on to the partitions on this device any longer.

This is caused by the removed call to set_disk_ro().

Is this intentional or was this removed by accident?

> -	rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, intval);
> +	if (!ro && test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
> +		rc = -EROFS;
> +	else
> +		rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, ro);
>  	dasd_put_device(base);
>  	return rc;
>  }
> @@ -633,9 +627,6 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
>  	case BIODASDPRRST:
>  		rc = dasd_ioctl_reset_profile(block);
>  		break;
> -	case BLKROSET:
> -		rc = dasd_ioctl_set_ro(bdev, argp);
> -		break;
>  	case DASDAPIVER:
>  		rc = dasd_ioctl_api_version(argp);
>  		break;
> -- 
> 2.28.0
> 

Re: [PATCH 05/10] md: implement ->set_read_only to hook into BLKROSET processing

[Song Liu]

On Tue, Nov 3, 2020 at 2:13 AM Christoph Hellwig <hch@lst.de> wrote:
>
> Implement the ->set_read_only method instead of parsing the actual
> ioctl command.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

LGTM!

Acked-by: Song Liu <song@kernel.org>

Re: [PATCH 06/10] dasd: implement ->set_read_only to hook into BLKROSET processing

[Christoph Hellwig]

On Thu, Nov 05, 2020 at 09:56:47PM +0100, Stefan Haberland wrote:
> > +	/* do not manipulate hardware state for partitions */
> >  	if (bdev_is_partition(bdev))
> > -		// ro setting is not allowed for partitions
> > -		return -EINVAL;
> > -	if (get_user(intval, (int __user *)argp))
> > -		return -EFAULT;
> > +		return 0;
> > +
> >  	base = dasd_device_from_gendisk(bdev->bd_disk);
> >  	if (!base)
> >  		return -ENODEV;
> > -	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
> > -		dasd_put_device(base);
> > -		return -EROFS;
> > -	}
> > -	set_disk_ro(bdev->bd_disk, intval);
> 
> 
> While testing this patch I just noticed that when I set a device readonly this is
> not going to be passed on to the partitions on this device any longer.
> 
> This is caused by the removed call to set_disk_ro().
> 
> Is this intentional or was this removed by accident?

It was unintentionally intentional :)

The generic code used already by almost all drivers in mainline only
calls set_device_ro from blkdev_roset, that is it only sets the main
device read-only.  dasd was the outlier here, and I didn't notice it
actually called set_disk_ro instead of set_device_ro.   That being
said I think setting all the partitions read-only as well when the
full device is set read-only makes perfect sense.  I'm just a little
worried it could cause regressions.  Let me prepare a follow on patch
on top of the series that switches to that behavior.

Re: [PATCH 06/10] dasd: implement ->set_read_only to hook into BLKROSET processing

[Stefan Haberland]

Christoph Hellwig <hch@lst.de> schrieb am Fri, 06. Nov 15:02:
> On Thu, Nov 05, 2020 at 09:56:47PM +0100, Stefan Haberland wrote:
> > > +	/* do not manipulate hardware state for partitions */
> > >  	if (bdev_is_partition(bdev))
> > > -		// ro setting is not allowed for partitions
> > > -		return -EINVAL;
> > > -	if (get_user(intval, (int __user *)argp))
> > > -		return -EFAULT;
> > > +		return 0;
> > > +
> > >  	base = dasd_device_from_gendisk(bdev->bd_disk);
> > >  	if (!base)
> > >  		return -ENODEV;
> > > -	if (!intval && test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
> > > -		dasd_put_device(base);
> > > -		return -EROFS;
> > > -	}
> > > -	set_disk_ro(bdev->bd_disk, intval);
> > 
> > 
> > While testing this patch I just noticed that when I set a device readonly this is
> > not going to be passed on to the partitions on this device any longer.
> > 
> > This is caused by the removed call to set_disk_ro().
> > 
> > Is this intentional or was this removed by accident?
> 
> It was unintentionally intentional :)
> 
> The generic code used already by almost all drivers in mainline only
> calls set_device_ro from blkdev_roset, that is it only sets the main
> device read-only.  dasd was the outlier here, and I didn't notice it
> actually called set_disk_ro instead of set_device_ro.   That being
> said I think setting all the partitions read-only as well when the
> full device is set read-only makes perfect sense.  I'm just a little
> worried it could cause regressions.  Let me prepare a follow on patch
> on top of the series that switches to that behavior.

Makes sense.
I am fine with that.

With this in mind:

Reviewed-by: Stefan Haberland <sth@linux.ibm.com>

Re: block ioctl cleanups v2

[Christoph Hellwig]

Jens, can you take a look and possibly pick this series up?

On Tue, Nov 03, 2020 at 11:00:08AM +0100, Christoph Hellwig wrote:
> Hi Jens,
> 
> this series has a bunch of cleanups for the block layer ioctl code.
> 
> Changes since v1:
>  - drop the patch to return the correct error for unknown ioctls in mtip
>  - add back an empty line in rbd
>  - various spelling fixes
---end quoted text---

Re: block ioctl cleanups v2

[Jens Axboe]

On 11/11/20 12:58 AM, Christoph Hellwig wrote:
> Jens, can you take a look and possibly pick this series up?

Looks good to me - but what is the final resolution on the BLKROSET
propagation?

-- 
Jens Axboe

Re: block ioctl cleanups v2

[Christoph Hellwig]

On Wed, Nov 11, 2020 at 09:13:05AM -0700, Jens Axboe wrote:
> On 11/11/20 12:58 AM, Christoph Hellwig wrote:
> > Jens, can you take a look and possibly pick this series up?
> 
> Looks good to me - but what is the final resolution on the BLKROSET
> propagation?

Do it properly including a hard read only flag.  Martin has an old
patch that I'm going to forward port.  For now I think we need to
adjust dasd to match the behavior of all drivers, so that we can fix
the common code to behave more like dasd in the next step.

Re: block ioctl cleanups v2

[Jens Axboe]

On 11/11/20 9:20 AM, Christoph Hellwig wrote:
> On Wed, Nov 11, 2020 at 09:13:05AM -0700, Jens Axboe wrote:
>> On 11/11/20 12:58 AM, Christoph Hellwig wrote:
>>> Jens, can you take a look and possibly pick this series up?
>>
>> Looks good to me - but what is the final resolution on the BLKROSET
>> propagation?
> 
> Do it properly including a hard read only flag.  Martin has an old
> patch that I'm going to forward port.  For now I think we need to
> adjust dasd to match the behavior of all drivers, so that we can fix
> the common code to behave more like dasd in the next step.

I applied the series, so just send something for this on top.

-- 
Jens Axboe