FAILED: patch "[PATCH] block: flag zoned disks with GENHD_FL_NO_PART" failed to apply to 5.10-stable tree

PATCH New [email protected] 2 participants 8 messages Sep 8 – Sep 10

Subsystems (2)

Stable branch Block layer

lore

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lore

[email protected]

author maintainer

2026-09-08 13:43 UTC #0 lore raw

The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 3f9c7a108c0e8f14425384912017071b71341e3b
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026090834-voyage-donut-60bd@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3f9c7a108c0e8f14425384912017071b71341e3b Mon Sep 17 00:00:00 2001
From: Damien Le Moal <[email protected]>
Date: Mon, 31 Aug 2026 11:50:50 +0900
Subject: [PATCH] block: flag zoned disks with GENHD_FL_NO_PART

Zoned block devices do not support partitions. However, the partition table is nevertheless still inspected, and any partition found ignored with a warning in add_partition(). While this is generally not a problem, and in fact beneficial to the user as it indicates an invalid use of a zoned block device, scanning for a partition table on the device may result in issuing read operations to offline zones (e.g. after a disk head is depopulated for disks that support head management operations).

Since partitions are ignored anyway, completely disable partition scanning for zoned gendisks by setting the flag GENHD_FL_NO_PART in __add_disk(). The existing check in add_partition() is left as-is to ensure that we still get a warning if for whatever reason, despite GENHD_FL_NO_PART, we still endup trying to add partitions.

Flagging zoned disks with GENHD_FL_NO_PART also has the benefit to expose through sysfs the ext_range attribute with the value of 1 instead of the default DISK_MAX_PARTS, thus correctly advertizing the fact that zoned disks do not support partitions.

Fixes 5eac3eb30c9a ("block: Remove partition support for zoned block devices")

Cc [email protected]

Signed-off-by Damien Le Moal <[email protected]>

Reviewed-by Bart Van Assche <[email protected]>

Reviewed-by Hannes Reinecke <[email protected]>

Reviewed-by Christoph Hellwig <[email protected]>

Reviewed-by Hannes Reinecke <[email protected]>

Link https://patch.msgid.link/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

block/genhd.c +7 -0

index f1990c7cdfb9..10ca8b4d6eea 100644
@@ -447,6 +447,13 @@ static int __add_disk(struct device *parent, struct gendisk *disk,
 		bdev_set_flag(disk->part0, BD_HAS_SUBMIT_BIO);
 	}
 
+	/*
+	 * We do not support partitions with zoned block devices, so do not try
+	 * to scan the partitions table.
+	 */
+	if (blk_queue_is_zoned(disk->queue))
+		disk->flags |= GENHD_FL_NO_PART;
+
 	/*
 	 * If the driver provides an explicit major number it also must provide
 	 * the number of minors numbers supported, and those will be used to

Sasha Levin

maintainer

2026-09-10 19:08 UTC #1 lore raw

PATCH 1/7 block: remove a dead check in show_partition

From: Christoph Hellwig <[email protected]>

[ Upstream commit e3b3bad3f29878d13fdbc96f9e59674bd9b06bae ]

disk_max_parts never returns 0 given that ->minors for devices not using the extended dev_t must be non-zero, and disk_max_parts always returns DISK_MAX_PARTS for the latter.

Signed-off-by Christoph Hellwig <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Stable-dep-of: 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART")

Signed-off-by Sasha Levin <[email protected]>

---
 block/genhd.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

block/genhd.c +1 -3

index 768a49460bf19..01a7b81eca751 100644
@@ -1174,9 +1174,7 @@ static int show_partition(struct seq_file *seqf, void *v)
 	struct hd_struct *part;
 	char buf[BDEVNAME_SIZE];
 
-	/* Don't show non-partitionable removeable devices or empty devices */
-	if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
-				   (sgp->flags & GENHD_FL_REMOVABLE)))
+	if (!get_capacity(sgp))
 		return 0;
 	if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 		return 0;

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-10 19:08 UTC #2 lore raw

PATCH 2/7 block: rename GENHD_FL_NO_PART_SCAN to GENHD_FL_NO_PART

From: Christoph Hellwig <[email protected]>

[ Upstream commit 46e7eac647b34ed4106a8262f8bedbb90801fadd ]

The GENHD_FL_NO_PART_SCAN controls more than just partitions canning, so rename it to GENHD_FL_NO_PART.

Signed-off-by Christoph Hellwig <[email protected]>

Acked-by Ulf Hansson <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Adapt the dependency for 5.10 and prepare for 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART"):

Keep the loop_set_status() block-device assignment and the native-capacity and exclusive-write event flags, which are still needed on this branch. Drop the n64cart hunk because that driver does not exist in 5.10.

Move the existing register_disk() definition below __device_add_disk(), with a forward declaration, and align the device-number comment with upstream. This preserves the existing registration logic while allowing the target's three-way cherry-pick to insert its zoned-disk check in __device_add_disk(), before partition scanning. No functions are added.

Make ext_range report one for GENHD_FL_NO_PART disks, as expected by the target, while retaining disk_max_parts() for other disks. Keep the existing partition allocation limits and extended device-number handling.

[ sashal: Reduced backport -- upstream 46e7eac647b34 touches 5 file(s), this
backport carries 4. Not backported here:
drivers/block/n64cart.c
This note is generated from the file lists only; see the resolution record for the reasoning. ]

Stable-dep-of: 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART")

Signed-off-by Sasha Levin <[email protected]>

---
 block/genhd.c            | 137 +++++++++++++++++++++------------------
 drivers/block/loop.c     |   8 +--
 drivers/mmc/core/block.c |   4 +-
 include/linux/genhd.h    |  13 ++--
 4 files changed, 85 insertions(+), 77 deletions(-)

block/genhd.c +73 ~~-64~~

index 01a7b81eca751..fef31a2f50a80 100644
@@ -690,67 +690,7 @@ static void disk_scan_partitions(struct gendisk *disk)
 }
 
 static void register_disk(struct device *parent, struct gendisk *disk,
-			  const struct attribute_group **groups)
-{
-	struct device *ddev = disk_to_dev(disk);
-	struct disk_part_iter piter;
-	struct hd_struct *part;
-	int err;
-
-	ddev->parent = parent;
-
-	dev_set_name(ddev, "%s", disk->disk_name);
-
-	/* delay uevents, until we scanned partition table */
-	dev_set_uevent_suppress(ddev, 1);
-
-	if (groups) {
-		WARN_ON(ddev->groups);
-		ddev->groups = groups;
-	}
-	if (device_add(ddev))
-		return;
-	if (!sysfs_deprecated) {
-		err = sysfs_create_link(block_depr, &ddev->kobj,
-					kobject_name(&ddev->kobj));
-		if (err) {
-			device_del(ddev);
-			return;
-		}
-	}
-
-	/*
-	 * avoid probable deadlock caused by allocating memory with
-	 * GFP_KERNEL in runtime_resume callback of its all ancestor
-	 * devices
-	 */
-	pm_runtime_set_memalloc_noio(ddev, true);
-
-	disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
-	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
-
-	if (disk->flags & GENHD_FL_HIDDEN)
-		return;
-
-	disk_scan_partitions(disk);
-
-	/* announce disk after possible partitions are created */
-	dev_set_uevent_suppress(ddev, 0);
-	kobject_uevent(&ddev->kobj, KOBJ_ADD);
-
-	/* announce possible partitions */
-	disk_part_iter_init(&piter, disk, 0);
-	while ((part = disk_part_iter_next(&piter)))
-		kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
-	disk_part_iter_exit(&piter);
-
-	if (disk->queue->backing_dev_info->dev) {
-		err = sysfs_create_link(&ddev->kobj,
-			  &disk->queue->backing_dev_info->dev->kobj,
-			  "bdi");
-		WARN_ON(err);
-	}
-}
+			  const struct attribute_group **groups);
 
 /**
  * __device_add_disk - add disk information to kernel list

@@ -780,7 +720,12 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 	if (register_queue)
 		elevator_init_mq(disk->queue);
 
-	/* minors == 0 indicates to use ext devt from part0 and should
+	/*
+	 * If the driver provides an explicit major number it also must provide
+	 * the number of minors numbers supported, and those will be used to
+	 * setup the gendisk.
+	 *
+	 * minors == 0 indicates to use ext devt from part0 and should
 	 * be accompanied with EXT_DEVT flag.  Make sure all
 	 * parameters make sense.
 	 */

@@ -806,7 +751,7 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 		 * and don't bother scanning for partitions either.
 		 */
 		disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
-		disk->flags |= GENHD_FL_NO_PART_SCAN;
+		disk->flags |= GENHD_FL_NO_PART;
 	} else {
 		struct backing_dev_info *bdi = disk->queue->backing_dev_info;
 		struct device *dev = disk_to_dev(disk);

@@ -834,6 +779,69 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 	blk_integrity_add(disk);
 }
 
+static void register_disk(struct device *parent, struct gendisk *disk,
+			  const struct attribute_group **groups)
+{
+	struct device *ddev = disk_to_dev(disk);
+	struct disk_part_iter piter;
+	struct hd_struct *part;
+	int err;
+
+	ddev->parent = parent;
+
+	dev_set_name(ddev, "%s", disk->disk_name);
+
+	/* delay uevents, until we scanned partition table */
+	dev_set_uevent_suppress(ddev, 1);
+
+	if (groups) {
+		WARN_ON(ddev->groups);
+		ddev->groups = groups;
+	}
+	if (device_add(ddev))
+		return;
+	if (!sysfs_deprecated) {
+		err = sysfs_create_link(block_depr, &ddev->kobj,
+					kobject_name(&ddev->kobj));
+		if (err) {
+			device_del(ddev);
+			return;
+		}
+	}
+
+	/*
+	 * avoid probable deadlock caused by allocating memory with
+	 * GFP_KERNEL in runtime_resume callback of its all ancestor
+	 * devices
+	 */
+	pm_runtime_set_memalloc_noio(ddev, true);
+
+	disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
+	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
+
+	if (disk->flags & GENHD_FL_HIDDEN)
+		return;
+
+	disk_scan_partitions(disk);
+
+	/* announce disk after possible partitions are created */
+	dev_set_uevent_suppress(ddev, 0);
+	kobject_uevent(&ddev->kobj, KOBJ_ADD);
+
+	/* announce possible partitions */
+	disk_part_iter_init(&piter, disk, 0);
+	while ((part = disk_part_iter_next(&piter)))
+		kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
+	disk_part_iter_exit(&piter);
+
+	if (disk->queue->backing_dev_info->dev) {
+		err = sysfs_create_link(&ddev->kobj,
+			  &disk->queue->backing_dev_info->dev->kobj,
+			  "bdi");
+		WARN_ON(err);
+	}
+}
+
 void device_add_disk(struct device *parent, struct gendisk *disk,
 		     const struct attribute_group **groups)

@@ -1242,7 +1250,8 @@ static ssize_t disk_ext_range_show(struct device *dev,
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
-	return sprintf(buf, "%d\n", disk_max_parts(disk));
+	return sprintf(buf, "%d\n",
+		       (disk->flags & GENHD_FL_NO_PART) ? 1 : disk_max_parts(disk));
 }
 
 static ssize_t disk_removable_show(struct device *dev,

drivers/block/loop.c +4 -4

index 3db4dad0d072a..e11e25a799aba 100644
@@ -1165,7 +1165,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 		lo->lo_flags |= LO_FLAGS_PARTSCAN;
 	partscan = lo->lo_flags & LO_FLAGS_PARTSCAN;
 	if (partscan)
-		lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN;
+		lo->lo_disk->flags &= ~GENHD_FL_NO_PART;
 
 	/* Grab the block_device to prevent its destruction after we
 	 * put /dev/loopXX inode. Later in __loop_clr_fd() we bdput(bdev).

@@ -1291,7 +1291,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
 	mutex_lock(&loop_ctl_mutex);
 	lo->lo_flags = 0;
 	if (!part_shift)
-		lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN;
+		lo->lo_disk->flags |= GENHD_FL_NO_PART;
 	lo->lo_state = Lo_unbound;
 	mutex_unlock(&loop_ctl_mutex);

@@ -1410,7 +1410,7 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 
 	if (!err && (lo->lo_flags & LO_FLAGS_PARTSCAN) &&
 	     !(prev_lo_flags & LO_FLAGS_PARTSCAN)) {
-		lo->lo_disk->flags &= ~GENHD_FL_NO_PART_SCAN;
+		lo->lo_disk->flags &= ~GENHD_FL_NO_PART;
 		bdev = lo->lo_device;
 		partscan = true;
 	}

@@ -2154,7 +2154,7 @@ static int loop_add(struct loop_device **l, int i)
 	 * userspace tools. Parameters like this in general should be avoided.
 	 */
 	if (!part_shift)
-		disk->flags |= GENHD_FL_NO_PART_SCAN;
+		disk->flags |= GENHD_FL_NO_PART;
 	disk->flags |= GENHD_FL_EXT_DEVT;
 	atomic_set(&lo->lo_refcnt, 0);
 	lo->lo_number		= i;

drivers/mmc/core/block.c +2 -2

index e5506c793b6bd..51b43895e3a2d 100644
@@ -2411,8 +2411,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	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_SCAN
-				   | GENHD_FL_SUPPRESS_PARTITION_INFO;
+		md->disk->flags |= GENHD_FL_NO_PART |
+				   GENHD_FL_SUPPRESS_PARTITION_INFO;
 
 	/*
 	 * As discussed on lkml, GENHD_FL_REMOVABLE should:

include/linux/genhd.h +6 -7

index 4b22bfd9336e1..30e1841630b1f 100644
@@ -111,15 +111,15 @@ struct hd_struct {
  * ``GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE`` (0x0100): event polling is
  * blocked whenever a writer holds an exclusive lock.
  *
- * ``GENHD_FL_NO_PART_SCAN`` (0x0200): partition scanning is disabled.
- * Used for loop devices in their default settings and some MMC
- * devices.
+ * ``GENHD_FL_NO_PART`` (0x0200): partition support is disabled.
+ * The kernel will not scan for partitions from add_disk, and users
+ * can't add partitions manually.
  *
  * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
  * doesn't produce events, doesn't appear in sysfs, and doesn't have
  * an associated ``bdev``.
  * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
- * ``GENHD_FL_NO_PART_SCAN``.
+ * ``GENHD_FL_NO_PART``.
  * Used for multipath devices.
  */
 #define GENHD_FL_REMOVABLE			0x0001

@@ -131,7 +131,7 @@ struct hd_struct {
 #define GENHD_FL_EXT_DEVT			0x0040
 #define GENHD_FL_NATIVE_CAPACITY		0x0080
 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	0x0100
-#define GENHD_FL_NO_PART_SCAN			0x0200
+#define GENHD_FL_NO_PART			0x0200
 #define GENHD_FL_HIDDEN				0x0400
 
 enum {

@@ -236,8 +236,7 @@ static inline int disk_max_parts(struct gendisk *disk)
 
 static inline bool disk_part_scan_enabled(struct gendisk *disk)
 {
-	return disk_max_parts(disk) > 1 &&
-		!(disk->flags & GENHD_FL_NO_PART_SCAN);
+	return disk_max_parts(disk) > 1 && !(disk->flags & GENHD_FL_NO_PART);
 }
 
 static inline dev_t disk_devt(struct gendisk *disk)

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-10 19:08 UTC #3 lore raw

PATCH 3/7 null_blk: don't suppress partitioning information

In reply to Sasha Levin

From: Christoph Hellwig <[email protected]>

[ Upstream commit 94b49c3ddb2127f84a133d70cef49054e1ebaaa4 ]

This manually reverts commit 27290b469051 ("null_blk: suppress invalid partition info"). The message in that commit log can't appearch as the flag is never checked during probing, and there is no good reason to treat null_blk special in /proc/partitions.

Signed-off-by Christoph Hellwig <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Stable-dep-of: 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART")

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/block/null_blk/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/block/null_blk/main.c +1 -1

index 8e24fb93324cb..de14af5232ae2 100644
@@ -1692,7 +1692,7 @@ static int null_gendisk_register(struct nullb *nullb)
 		return -ENOMEM;
 	set_capacity(disk, size);
 
-	disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO;
+	disk->flags |= GENHD_FL_EXT_DEVT;
 	disk->major		= null_major;
 	disk->first_minor	= nullb->index;
 	if (queue_is_mq(nullb->q))

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-10 19:08 UTC #4 lore raw

PATCH 4/7 mmc: don't set GENHD_FL_SUPPRESS_PARTITION_INFO

In reply to Sasha Levin

From: Christoph Hellwig <[email protected]>

[ Upstream commit 79b0f79a835c6f1103c06e449cd88fb13e67f405 ]

This manually reverts 07b652cdbec3 ("mmc: card: Don't show eMMC RPMB and BOOT areas in /proc/partitions"). Based on the commit description that change was purely cosmetic. mmc is the last driver that sets this flag and thus prevents it from being removed.

Signed-off-by Christoph Hellwig <[email protected]>

Acked-by Ulf Hansson <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Stable-dep-of: 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART")

Signed-off-by Sasha Levin <[email protected]>

---
 drivers/mmc/core/block.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

drivers/mmc/core/block.c +1 -2

index 51b43895e3a2d..1f7f52697b1e4 100644
@@ -2411,8 +2411,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	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 |
-				   GENHD_FL_SUPPRESS_PARTITION_INFO;
+		md->disk->flags |= GENHD_FL_NO_PART;
 
 	/*
 	 * As discussed on lkml, GENHD_FL_REMOVABLE should:

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-10 19:08 UTC #5 lore raw

PATCH 5/7 block: remove GENHD_FL_SUPPRESS_PARTITION_INFO

In reply to Sasha Levin

From: Christoph Hellwig <[email protected]>

[ Upstream commit 3b5149ac50970669ee0ddb9629ec77ffd5c0622d ]

This flag is not set directly anywhere and only inherited from GENHD_FL_HIDDEN. Just check for GENHD_FL_HIDDEN instead.

Signed-off-by Christoph Hellwig <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Adapt the dependency to the 5.10 disk-registration layout. Remove the hidden-disk suppression assignment from __device_add_disk(), where this branch sets GENHD_FL_NO_PART, and keep register_disk() and its existing uevent and backing-device registration flow intact.

Preserve GENHD_FL_CD, GENHD_FL_UP, GENHD_FL_NATIVE_CAPACITY and GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE, which are still used on this branch. Only remove GENHD_FL_SUPPRESS_PARTITION_INFO and check GENHD_FL_HIDDEN in both partition-listing paths. No functions are added.

The preceding dependencies already removed the MMC and null_blk users. Verified that target 3f9c7a108c0e applies cleanly with a three-way merge, inserting its zoned-disk check in __device_add_disk() before partition scanning. The existing GENHD_FL_NO_PART ext_range handling is retained.

Stable-dep-of: 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART")

Signed-off-by Sasha Levin <[email protected]>

---
 block/genhd.c         | 11 +++--------
 include/linux/genhd.h |  9 +--------
 2 files changed, 4 insertions(+), 16 deletions(-)

block/genhd.c +3 -8

index fef31a2f50a80..4ecab2f503719 100644
@@ -747,10 +747,8 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 
 	if (disk->flags & GENHD_FL_HIDDEN) {
 		/*
-		 * Don't let hidden disks show up in /proc/partitions,
-		 * and don't bother scanning for partitions either.
+		 * Don't bother scanning for partitions.
 		 */
-		disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
 		disk->flags |= GENHD_FL_NO_PART;
 	} else {
 		struct backing_dev_info *bdi = disk->queue->backing_dev_info;

@@ -1086,8 +1084,7 @@ void __init printk_all_partitions(void)
 		 * Don't show empty devices or things that have been
 		 * suppressed
 		 */
-		if (get_capacity(disk) == 0 ||
-		    (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
+		if (get_capacity(disk) == 0 || (disk->flags & GENHD_FL_HIDDEN))
 			continue;
 
 		/*

@@ -1182,9 +1179,7 @@ static int show_partition(struct seq_file *seqf, void *v)
 	struct hd_struct *part;
 	char buf[BDEVNAME_SIZE];
 
-	if (!get_capacity(sgp))
-		return 0;
-	if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
+	if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN))
 		return 0;
 
 	/* show the full disk and all non-0 size partitions of it */

include/linux/genhd.h +1 -8

index 30e1841630b1f..d6892e2f31c37 100644
@@ -92,11 +92,6 @@ struct hd_struct {
  * ``GENHD_FL_UP`` (0x0010): indicates that the block device is "up",
  * with a similar meaning to network interfaces.
  *
- * ``GENHD_FL_SUPPRESS_PARTITION_INFO`` (0x0020): don't include
- * partition information in ``/proc/partitions`` or in the output of
- * printk_all_partitions().
- * Used for the null block device and some MMC devices.
- *
  * ``GENHD_FL_EXT_DEVT`` (0x0040): the driver supports extended
  * dynamic ``dev_t``, i.e. it wants extended device numbers
  * (``BLOCK_EXT_MAJOR``).

@@ -118,8 +113,7 @@ struct hd_struct {
  * ``GENHD_FL_HIDDEN`` (0x0400): the block device is hidden; it
  * doesn't produce events, doesn't appear in sysfs, and doesn't have
  * an associated ``bdev``.
- * Implies ``GENHD_FL_SUPPRESS_PARTITION_INFO`` and
- * ``GENHD_FL_NO_PART``.
+ * Implies ``GENHD_FL_NO_PART``.
  * Used for multipath devices.
  */
 #define GENHD_FL_REMOVABLE			0x0001

@@ -127,7 +121,6 @@ struct hd_struct {
 /* 4 is unused (used to be GENHD_FL_MEDIA_CHANGE_NOTIFY) */
 #define GENHD_FL_CD				0x0008
 #define GENHD_FL_UP				0x0010
-#define GENHD_FL_SUPPRESS_PARTITION_INFO	0x0020
 #define GENHD_FL_EXT_DEVT			0x0040
 #define GENHD_FL_NATIVE_CAPACITY		0x0080
 #define GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE	0x0100

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-10 19:08 UTC #6 lore raw

PATCH 6/7 block: don't set GENHD_FL_NO_PART for hidden gendisks

In reply to Sasha Levin

From: Christoph Hellwig <[email protected]>

[ Upstream commit 9f18db572c97bc327b63528d195fdb252f47e9de ]

Hidden gendisks can't be opened using blkdev_get_*, so we can't really reach any of the partition scanning paths or partitioning ioctls except for the initial partition scan from add_disk.

Signed-off-by Christoph Hellwig <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Adapt the dependency to the 5.10 disk-registration layout. Keep the void disk_scan_partitions() interface and its capacity and partition-scan checks, adding a direct GENHD_FL_HIDDEN check before requesting a scan.

Remove the implicit GENHD_FL_NO_PART assignment from __device_add_disk(), where this branch handles hidden disks. Preserve its existing BDI and region registration, and keep register_disk()'s hidden-disk early return, uevents and sysfs links intact. No functions are added.

Verified that target 3f9c7a108c0e applies cleanly with a three-way merge, placing its zoned-disk check in __device_add_disk() before partition scanning. The existing GENHD_FL_NO_PART ext_range handling is retained.

Stable-dep-of: 3f9c7a108c0e ("block: flag zoned disks with GENHD_FL_NO_PART")

Signed-off-by Sasha Levin <[email protected]>

---
 block/genhd.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

block/genhd.c +3 -7

index 4ecab2f503719..ea81203f6a036 100644
@@ -680,7 +680,8 @@ static void disk_scan_partitions(struct gendisk *disk)
 {
 	struct block_device *bdev;
 
-	if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
+	if (!get_capacity(disk) || !disk_part_scan_enabled(disk) ||
+	    (disk->flags & GENHD_FL_HIDDEN))
 		return;
 
 	set_bit(GD_NEED_PART_SCAN, &disk->state);

@@ -745,12 +746,7 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 
 	disk_alloc_events(disk);
 
-	if (disk->flags & GENHD_FL_HIDDEN) {
-		/*
-		 * Don't bother scanning for partitions.
-		 */
-		disk->flags |= GENHD_FL_NO_PART;
-	} else {
+	if (!(disk->flags & GENHD_FL_HIDDEN)) {
 		struct backing_dev_info *bdi = disk->queue->backing_dev_info;
 		struct device *dev = disk_to_dev(disk);
 		int ret;

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-10 19:08 UTC #7 lore raw

PATCH 7/7 block: flag zoned disks with GENHD_FL_NO_PART

In reply to Sasha Levin

From: Damien Le Moal <[email protected]>

[ Upstream commit 3f9c7a108c0e8f14425384912017071b71341e3b ]

Fixes 5eac3eb30c9a ("block: Remove partition support for zoned block devices")

Cc [email protected]

Signed-off-by Damien Le Moal <[email protected]>

Reviewed-by Bart Van Assche <[email protected]>

Reviewed-by Hannes Reinecke <[email protected]>

Reviewed-by Christoph Hellwig <[email protected]>

Reviewed-by Hannes Reinecke <[email protected]>

Link https://patch.msgid.link/[email protected] open here

Signed-off-by Jens Axboe <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

---
 block/genhd.c | 7 +++++++
 1 file changed, 7 insertions(+)

block/genhd.c +7 -0

index ea81203f6a036..976d2d77a1e0f 100644
@@ -721,6 +721,13 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk,
 	if (register_queue)
 		elevator_init_mq(disk->queue);
 
+	/*
+	 * We do not support partitions with zoned block devices, so do not try
+	 * to scan the partitions table.
+	 */
+	if (blk_queue_is_zoned(disk->queue))
+		disk->flags |= GENHD_FL_NO_PART;
+
 	/*
 	 * If the driver provides an explicit major number it also must provide
 	 * the number of minors numbers supported, and those will be used to

Signature · 1 line

2.53.0