block: remove GENHD_FL_EXT_DEVT

All modern drivers can support extra partitions using the extended
dev_t.  In fact except for the ioctl method drivers never even see
partitions in normal operation.

So remove the GENHD_FL_EXT_DEVT and allow extra partitions for all
block devices that do support partitions, and require those that
do not support partitions to explicit disallow them using
GENHD_FL_NO_PART.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211122130625.1136848-12-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

24 files changed, 18 insertions, 17 deletions

diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index bf5c124c5452..1eec5113d0b5 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1790,6 +1790,7 @@ static int fd_alloc_disk(int drive, int system)
 	disk->first_minor = drive + system;
 	disk->minors = 1;
 	disk->fops = &floppy_fops;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	if (system)
 		sprintf(disk->disk_name, "fd%d_msdos", drive);
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index bf769e6e32fe..f3ff9babdb5c 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -2000,6 +2000,7 @@ static int ataflop_alloc_disk(unsigned int drive, unsigned int type)
 	disk->minors = 1;
 	sprintf(disk->disk_name, "fd%d", drive);
 	disk->fops = &floppy_fops;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->private_data = &unit[drive];
 	set_capacity(disk, MAX_DISK_SIZE * 2);
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index a896ee175d86..8fe2e4289dae 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -405,7 +405,6 @@ static int brd_alloc(int i)
 	disk->minors		= max_part;
 	disk->fops		= &brd_fops;
 	disk->private_data	= brd;
-	disk->flags		= GENHD_FL_EXT_DEVT;
 	strlcpy(disk->disk_name, buf, DISK_NAME_LEN);
 	set_capacity(disk, rd_size * 2);
 	
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 53ba2dddba6e..07b3c6093e7d 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2734,6 +2734,7 @@ enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsig
 	disk->first_minor = minor;
 	disk->minors = 1;
 	disk->fops = &drbd_ops;
+	disk->flags |= GENHD_FL_NO_PART;
 	sprintf(disk->disk_name, "drbd%d", minor);
 	disk->private_data = device;
 
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index c4267da716fe..7f0a60c4079f 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -4503,6 +4503,7 @@ static int floppy_alloc_disk(unsigned int drive, unsigned int type)
 	disk->first_minor = TOMINOR(drive) | (type << 2);
 	disk->minors = 1;
 	disk->fops = &floppy_fops;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	if (type)
 		sprintf(disk->disk_name, "fd%d_type%d", drive, type);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 7219d98c6fb8..0954ea8cf9e3 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -2033,7 +2033,6 @@ static int loop_add(int i)
 	 */
 	if (!part_shift)
 		disk->flags |= GENHD_FL_NO_PART;
-	disk->flags |= GENHD_FL_EXT_DEVT;
 	atomic_set(&lo->lo_refcnt, 0);
 	mutex_init(&lo->lo_mutex);
 	lo->lo_number		= i;
diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index eb17def1f265..54f7d490f8eb 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -1850,7 +1850,6 @@ static int null_gendisk_register(struct nullb *nullb)
 
 	set_capacity(disk, size);
 
-	disk->flags |= GENHD_FL_EXT_DEVT;
 	disk->major		= null_major;
 	disk->first_minor	= nullb->index;
 	disk->minors		= 1;
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 430ee8004a51..255fd3d4b8a8 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -928,6 +928,7 @@ static int pcd_init_unit(struct pcd_unit *cd, bool autoprobe, int port,
 	disk->minors = 1;
 	strcpy(disk->disk_name, cd->name);	/* umm... */
 	disk->fops = &pcd_bdops;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->event_flags = DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE;
 
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index bf8d0ef41a0a..b84a6448a4f7 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -942,6 +942,7 @@ static int __init pf_init_unit(struct pf_unit *pf, bool autoprobe, int port,
 	disk->minors = 1;
 	strcpy(disk->disk_name, pf->name);
 	disk->fops = &pf_fops;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->private_data = pf;
 
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index b53f648302c1..3af0499857ec 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2719,7 +2719,7 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 	disk->first_minor = idx;
 	disk->minors = 1;
 	disk->fops = &pktcdvd_ops;
-	disk->flags = GENHD_FL_REMOVABLE;
+	disk->flags = GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
 	strcpy(disk->disk_name, pd->name);
 	disk->private_data = pd;
 
diff --git a/drivers/block/ps3vram.c b/drivers/block/ps3vram.c
index c1876646a4cb..4f90819e245e 100644
--- a/drivers/block/ps3vram.c
+++ b/drivers/block/ps3vram.c
@@ -742,6 +742,7 @@ static int ps3vram_probe(struct ps3_system_bus_device *dev)
 	priv->gendisk = gendisk;
 	gendisk->major = ps3vram_major;
 	gendisk->minors = 1;
+	gendisk->flags |= GENHD_FL_NO_PART;
 	gendisk->fops = &ps3vram_fops;
 	gendisk->private_data = dev;
 	strlcpy(gendisk->disk_name, DEVICE_NAME, sizeof(gendisk->disk_name));
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 953fa134cd3d..8f140da1efe3 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4924,12 +4924,10 @@ static int rbd_init_disk(struct rbd_device *rbd_dev)
 		 rbd_dev->dev_id);
 	disk->major = rbd_dev->major;
 	disk->first_minor = rbd_dev->minor;
-	if (single_major) {
+	if (single_major)
 		disk->minors = (1 << RBD_SINGLE_MAJOR_PART_SHIFT);
-		disk->flags |= GENHD_FL_EXT_DEVT;
-	} else {
+	else
 		disk->minors = RBD_MINORS_PER_MAJOR;
-	}
 	disk->fops = &rbd_bd_ops;
 	disk->private_data = rbd_dev;
 
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 821594cd1315..fef65a18d56f 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -840,6 +840,7 @@ static int swim_floppy_init(struct swim_priv *swd)
 		swd->unit[drive].disk->minors = 1;
 		sprintf(swd->unit[drive].disk->disk_name, "fd%d", drive);
 		swd->unit[drive].disk->fops = &floppy_fops;
+		swd->unit[drive].disk->flags |= GENHD_FL_NO_PART;
 		swd->unit[drive].disk->events = DISK_EVENT_MEDIA_CHANGE;
 		swd->unit[drive].disk->private_data = &swd->unit[drive];
 		set_capacity(swd->unit[drive].disk, 2880);
diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 4b91c9aa5892..6c39f2c9f806 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -1227,7 +1227,7 @@ static int swim3_attach(struct macio_dev *mdev,
 	disk->fops = &floppy_fops;
 	disk->private_data = fs;
 	disk->events = DISK_EVENT_MEDIA_CHANGE;
-	disk->flags |= GENHD_FL_REMOVABLE;
+	disk->flags |= GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
 	sprintf(disk->disk_name, "fd%d", floppy_count);
 	set_capacity(disk, 2880);
 	rc = add_disk(disk);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 6ae38776e30e..cfa303fa7318 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -843,7 +843,6 @@ static int virtblk_probe(struct virtio_device *vdev)
 	vblk->disk->minors = 1 << PART_BITS;
 	vblk->disk->private_data = vblk;
 	vblk->disk->fops = &virtblk_fops;
-	vblk->disk->flags |= GENHD_FL_EXT_DEVT;
 	vblk->index = index;
 
 	/* configure queue flush support */
diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c
index ccc52c935faf..7a6ed83481b8 100644
--- a/drivers/block/z2ram.c
+++ b/drivers/block/z2ram.c
@@ -327,6 +327,7 @@ static int z2ram_register_disk(int minor)
 	disk->major = Z2RAM_MAJOR;
 	disk->first_minor = minor;
 	disk->minors = 1;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->fops = &z2_fops;
 	if (minor)
 		sprintf(disk->disk_name, "z2ram%d", minor);
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 25071126995b..f6da5293b913 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1947,6 +1947,7 @@ static int zram_add(void)
 	zram->disk->major = zram_major;
 	zram->disk->first_minor = device_id;
 	zram->disk->minors = 1;
+	zram->disk->flags |= GENHD_FL_NO_PART;
 	zram->disk->fops = &zram_devops;
 	zram->disk->private_data = zram;
 	snprintf(zram->disk->disk_name, 16, "zram%d", device_id);
diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
index d50cc1fd34d5..faead41709bc 100644
--- a/drivers/cdrom/gdrom.c
+++ b/drivers/cdrom/gdrom.c
@@ -719,6 +719,7 @@ static void probe_gdrom_setupdisk(void)
 	gd.disk->major = gdrom_major;
 	gd.disk->first_minor = 1;
 	gd.disk->minors = 1;
+	gd.disk->flags |= GENHD_FL_NO_PART;
 	strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
 }
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 662742a310cb..280918cdcabd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1778,6 +1778,7 @@ static struct mapped_device *alloc_dev(int minor)
 	md->disk->major = _major;
 	md->disk->first_minor = minor;
 	md->disk->minors = 1;
+	md->disk->flags |= GENHD_FL_NO_PART;
 	md->disk->fops = &dm_blk_dops;
 	md->disk->queue = md->queue;
 	md->disk->private_data = md;
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 5111ed966947..7fbf6f0ac01b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5707,11 +5707,6 @@ static int md_alloc(dev_t dev, char *name)
 	mddev->queue = disk->queue;
 	blk_set_stacking_limits(&mddev->queue->limits);
 	blk_queue_write_cache(mddev->queue, true, true);
-	/* Allow extended partitions.  This makes the
-	 * 'mdp' device redundant, but we can't really
-	 * remove it now.
-	 */
-	disk->flags |= GENHD_FL_EXT_DEVT;
 	disk->events |= DISK_EVENT_MEDIA_CHANGE;
 	mddev->gendisk = disk;
 	error = add_disk(disk);
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 2dd93d49d822..5e0960560eab 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -2395,7 +2395,6 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	md->disk->private_data = md;
 	md->parent = parent;
 	set_disk_ro(md->disk, md->read_only || default_ro);
-	md->disk->flags = GENHD_FL_EXT_DEVT;
 	if (area_type & (MMC_BLK_DATA_AREA_RPMB | MMC_BLK_DATA_AREA_BOOT))
 		md->disk->flags |= GENHD_FL_NO_PART;
 
diff --git a/drivers/mtd/ubi/block.c b/drivers/mtd/ubi/block.c
index 302426ab30f8..a78fdf3b30f7 100644
--- a/drivers/mtd/ubi/block.c
+++ b/drivers/mtd/ubi/block.c
@@ -430,6 +430,7 @@ int ubiblock_create(struct ubi_volume_info *vi)
 		ret = -ENODEV;
 		goto out_cleanup_disk;
 	}
+	gd->flags |= GENHD_FL_NO_PART;
 	gd->private_data = dev;
 	sprintf(gd->disk_name, "ubiblock%d_%d", dev->ubi_num, dev->vol_id);
 	set_capacity(gd, disk_capacity);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 65875a598d62..bba1f5dafd38 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3566,7 +3566,6 @@ static int sd_probe(struct device *dev)
 
 	sd_revalidate_disk(gd);
 
-	gd->flags = GENHD_FL_EXT_DEVT;
 	if (sdp->removable) {
 		gd->flags |= GENHD_FL_REMOVABLE;
 		gd->events |= DISK_EVENT_MEDIA_CHANGE;
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 6646797a7756..cf093387e42a 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -684,6 +684,7 @@ static int sr_probe(struct device *dev)
 	disk->minors = 1;
 	sprintf(disk->disk_name, "sr%d", minor);
 	disk->fops = &sr_bdops;
+	disk->flags |= GENHD_FL_NO_PART;
 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT |
 				DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE;