* [PATCH 17/19] init: factor out root device lookup into lookup_root_device()
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS root detection will also need to work if root_wait is set, meaning
that wait_for_root() needs to handle the DPS logic.
Move early_lookup_bdev() out of wait_for_root() into the new
lookup_root_device() so later changes can extend the lookup policy
without duplicating the retry logic.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
init/do_mounts.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 95e0b3a0f711..5fb5aeb88da9 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -402,6 +402,11 @@ void __init mount_root(char *root_device_name)
}
}
+static int __init lookup_root_device(char *root_device_name)
+{
+ return early_lookup_bdev(root_device_name, &ROOT_DEV);
+}
+
/* wait for any asynchronous scanning to complete */
static void __init wait_for_root(char *root_device_name)
{
@@ -415,7 +420,7 @@ static void __init wait_for_root(char *root_device_name)
end = ktime_add_ms(ktime_get_raw(), root_wait);
while (!driver_probe_done() ||
- early_lookup_bdev(root_device_name, &ROOT_DEV) < 0) {
+ lookup_root_device(root_device_name) < 0) {
msleep(5);
if (root_wait > 0 && ktime_after(ktime_get_raw(), end))
break;
--
2.53.0
^ permalink raw reply related
* [PATCH 16/19] block: don't discover partition with DPS no-auto GPT attribute
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] defines GPT attribute bit 63 as no-auto. Partitions with this
bit set must not be used by automatic discovery.
Add the new GPT_ATTRIBUTE_NO_AUTO flag to designate the GPT attribute
bit 63.
Add the new ADDPART_FLAG_NO_AUTO flag and set it when
GPT_ATTRIBUTE_NO_AUTO is set during the partition scan. Then, propagate
it to the new BD_NO_AUTO_DISCOVERY flag.
Finally, add a condition to match_dev_by_type_uuid() to exclude any
partition with that flag from the automatic discovery.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
block/blk.h | 1 +
block/early-lookup.c | 1 +
block/partitions/core.c | 2 ++
block/partitions/efi.c | 2 ++
block/partitions/efi.h | 3 +++
include/linux/blk_types.h | 1 +
6 files changed, 10 insertions(+)
diff --git a/block/blk.h b/block/blk.h
index b998a7761faf..14e0f349ff14 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -604,6 +604,7 @@ void blk_free_ext_minor(unsigned int minor);
#define ADDPART_FLAG_RAID 1
#define ADDPART_FLAG_WHOLEDISK 2
#define ADDPART_FLAG_READONLY 4
+#define ADDPART_FLAG_NO_AUTO 8
int bdev_add_partition(struct gendisk *disk, int partno, sector_t start,
sector_t length);
int bdev_del_partition(struct gendisk *disk, int partno);
diff --git a/block/early-lookup.c b/block/early-lookup.c
index cd10785e70ac..8db0abec141e 100644
--- a/block/early-lookup.c
+++ b/block/early-lookup.c
@@ -266,6 +266,7 @@ static int __init match_dev_by_type_uuid(struct device *dev, const void *data)
const struct uuidcmp *cmp = data;
return bdev->bd_disk == cmp->disk && bdev->bd_meta_info &&
+ !bdev_test_flag(bdev, BD_NO_AUTO_DISCOVERY) &&
!strcasecmp(cmp->uuid, bdev->bd_meta_info->type_uuid);
}
diff --git a/block/partitions/core.c b/block/partitions/core.c
index 5d5332ce586b..4529ea1d308e 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -382,6 +382,8 @@ static struct block_device *add_partition(struct gendisk *disk, int partno,
if (flags & ADDPART_FLAG_READONLY)
bdev_set_flag(bdev, BD_READ_ONLY);
+ if (flags & ADDPART_FLAG_NO_AUTO)
+ bdev_set_flag(bdev, BD_NO_AUTO_DISCOVERY);
/* everything is up and running, commence */
err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index 4a3835ed9561..50c21625e256 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -739,6 +739,8 @@ int efi_partition(struct parsed_partitions *state)
/* If this is a RAID volume, tell md */
if (!efi_guidcmp(ptes[i].partition_type_guid, PARTITION_LINUX_RAID_GUID))
state->parts[i + 1].flags = ADDPART_FLAG_RAID;
+ if (le64_to_cpu(ptes[i].attributes) & GPT_ATTRIBUTE_NO_AUTO)
+ state->parts[i + 1].flags |= ADDPART_FLAG_NO_AUTO;
info = &state->parts[i + 1].info;
efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
diff --git a/block/partitions/efi.h b/block/partitions/efi.h
index 1f56f93b2804..fb50edb66e84 100644
--- a/block/partitions/efi.h
+++ b/block/partitions/efi.h
@@ -11,6 +11,7 @@
#ifndef FS_PART_EFI_H_INCLUDED
#define FS_PART_EFI_H_INCLUDED
+#include <linux/bits.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/kernel.h>
@@ -30,6 +31,8 @@
#define GPT_HEADER_REVISION_V1 0x00010000
#define GPT_PRIMARY_PARTITION_TABLE_LBA 1
+#define GPT_ATTRIBUTE_NO_AUTO BIT_U64(63)
+
#define PARTITION_SYSTEM_GUID \
EFI_GUID( 0xC12A7328, 0xF81F, 0x11d2, \
0xBA, 0x4B, 0x00, 0xA0, 0xC9, 0x3E, 0xC9, 0x3B)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 8808ee76e73c..c6cdc99b0490 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -54,6 +54,7 @@ struct block_device {
#ifdef CONFIG_FAIL_MAKE_REQUEST
#define BD_MAKE_IT_FAIL (1u<<12)
#endif
+#define BD_NO_AUTO_DISCOVERY (1u<<13)
dev_t bd_dev;
struct address_space *bd_mapping; /* page cache */
--
2.53.0
^ permalink raw reply related
* [PATCH 15/19] block: store GPT attributes as a raw value
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
struct _gpt_entry_attributes currently models the GPT partition entry
attributes field with bitfields. This is broken on machines using the
__BIG_ENDIAN_BITFIELD ABI because GPT always stores the attributes on
disk as a 64-bit little-endian.
No current code consumes individual fields from that structure. So just
remove struct _gpt_entry_attributes entirely and replace it by an __le64
value in struct _gpt_entry.
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
block/partitions/efi.h | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/block/partitions/efi.h b/block/partitions/efi.h
index 84b9f36b9e47..1f56f93b2804 100644
--- a/block/partitions/efi.h
+++ b/block/partitions/efi.h
@@ -75,18 +75,12 @@ typedef struct _gpt_header {
*/
} __packed gpt_header;
-typedef struct _gpt_entry_attributes {
- u64 required_to_function:1;
- u64 reserved:47;
- u64 type_guid_specific:16;
-} __packed gpt_entry_attributes;
-
typedef struct _gpt_entry {
efi_guid_t partition_type_guid;
efi_guid_t unique_partition_guid;
__le64 starting_lba;
__le64 ending_lba;
- gpt_entry_attributes attributes;
+ __le64 attributes;
__le16 partition_name[72/sizeof(__le16)];
} __packed gpt_entry;
--
2.53.0
^ permalink raw reply related
* [PATCH 14/19] block: add early_lookup_bdev_by_type_uuid()
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
Add early_lookup_bdev_by_type_uuid() to find the root block device by
its GPT type UUID on the disk containing the active EFI System
Partition.
DPS [1] requires OS partition discovery to be limited to the disk
containing the active EFI System Partition. Reuse the existing block
class lookup and UUID matching callback to identify that disk, then do a
second lookup constrained to it. If the disk contains several partitions
with a matching type UUID, use the first match, following the DPS
discovery rule.
Extend struct uuidcmp with the new disk field so that it can be used in
the new match_dev_by_type_uuid() callback function.
Update devt_from_partuuid() to initialize cmp with a designated
initializer so that the new cmp.disk field is zero-initialized. This is
not strictly needed, but keeps the code cleaner.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
block/early-lookup.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++---
include/linux/blkdev.h | 4 +++
2 files changed, 68 insertions(+), 3 deletions(-)
diff --git a/block/early-lookup.c b/block/early-lookup.c
index 3fb57f7d2b12..cd10785e70ac 100644
--- a/block/early-lookup.c
+++ b/block/early-lookup.c
@@ -5,10 +5,12 @@
*/
#include <linux/blkdev.h>
#include <linux/ctype.h>
+#include <linux/uuid.h>
struct uuidcmp {
const char *uuid;
int len;
+ struct gendisk *disk;
};
/**
@@ -45,13 +47,11 @@ static int __init match_dev_by_uuid(struct device *dev, const void *data)
*/
static int __init devt_from_partuuid(const char *uuid_str, dev_t *devt)
{
- struct uuidcmp cmp;
+ struct uuidcmp cmp = { .uuid = uuid_str };
struct device *dev = NULL;
int offset = 0;
char *slash;
- cmp.uuid = uuid_str;
-
slash = strchr(uuid_str, '/');
/* Check for optional partition number offset attributes. */
if (slash) {
@@ -252,6 +252,67 @@ int __init early_lookup_bdev(const char *name, dev_t *devt)
return devt_from_devnum(name, devt);
}
+#ifdef CONFIG_DPS_ROOT_AUTO_DISCOVERY
+/**
+ * match_dev_by_type_uuid - callback for finding a partition using its type UUID
+ * @dev: device passed in by the caller
+ * @data: opaque pointer to the desired struct uuidcmp to match
+ *
+ * Returns: 1 if the device matches, and 0 otherwise.
+ */
+static int __init match_dev_by_type_uuid(struct device *dev, const void *data)
+{
+ struct block_device *bdev = dev_to_bdev(dev);
+ const struct uuidcmp *cmp = data;
+
+ return bdev->bd_disk == cmp->disk && bdev->bd_meta_info &&
+ !strcasecmp(cmp->uuid, bdev->bd_meta_info->type_uuid);
+}
+
+/**
+ * early_lookup_bdev_by_type_uuid - look up a partition by its type UUID
+ * @type_uuid: partition type UUID to search for
+ * @efi_partuuid: partition UUID identifying the active EFI partition
+ * @devt: matching dev_t result
+ *
+ * This helper follows the Discoverable Partitions Specification rules. It uses
+ * @efi_partuuid to find the disk containing the active EFI System Partition,
+ * then searches only partitions on that disk for the partition type UUID
+ * specified by @type_uuid.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int __init early_lookup_bdev_by_type_uuid(const char *type_uuid,
+ const char *efi_partuuid, dev_t *devt)
+{
+ struct uuidcmp efi_cmp = {
+ .uuid = efi_partuuid,
+ .len = UUID_STRING_LEN,
+ };
+ struct uuidcmp type_cmp = {
+ .uuid = type_uuid,
+ };
+ struct device *efi_dev;
+ struct device *type_dev;
+
+ efi_dev = class_find_device(&block_class, NULL, &efi_cmp,
+ &match_dev_by_uuid);
+ if (!efi_dev)
+ return -ENODEV;
+
+ type_cmp.disk = dev_to_disk(efi_dev);
+ type_dev = class_find_device(&block_class, NULL, &type_cmp,
+ &match_dev_by_type_uuid);
+ put_device(efi_dev);
+ if (!type_dev)
+ return -ENODEV;
+
+ *devt = type_dev->devt;
+ put_device(type_dev);
+ return 0;
+}
+#endif
+
static char __init *bdevt_str(dev_t devt, char *buf)
{
if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 8ce85d21a1f4..c2b7d07c92e7 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1800,6 +1800,10 @@ void sync_bdevs(bool wait);
void bdev_statx(const struct path *path, struct kstat *stat, u32 request_mask);
void printk_all_partitions(void);
int __init early_lookup_bdev(const char *pathname, dev_t *dev);
+#ifdef CONFIG_DPS_ROOT_AUTO_DISCOVERY
+int __init early_lookup_bdev_by_type_uuid(const char *type_uuid,
+ const char *efi_partuuid, dev_t *dev);
+#endif
#else
static inline void invalidate_bdev(struct block_device *bdev)
{
--
2.53.0
^ permalink raw reply related
* [PATCH 13/19] block: store GPT partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] identifies OS partitions by GPT partition type UUID.
Keep that UUID in partition_meta_info and populate it while scanning EFI
partition tables so early root discovery can use it.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
block/partitions/efi.c | 1 +
include/linux/blkdev.h | 1 +
2 files changed, 2 insertions(+)
diff --git a/block/partitions/efi.c b/block/partitions/efi.c
index 9865d59093fa..4a3835ed9561 100644
--- a/block/partitions/efi.c
+++ b/block/partitions/efi.c
@@ -742,6 +742,7 @@ int efi_partition(struct parsed_partitions *state)
info = &state->parts[i + 1].info;
efi_guid_to_str(&ptes[i].unique_partition_guid, info->uuid);
+ efi_guid_to_str(&ptes[i].partition_type_guid, info->type_uuid);
/* Naively convert UTF16-LE to 7 bits. */
label_max = min(ARRAY_SIZE(info->volname) - 1,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 890128cdea1c..8ce85d21a1f4 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -67,6 +67,7 @@ extern const struct class block_class;
struct partition_meta_info {
char uuid[PARTITION_META_INFO_UUIDLTH];
+ char type_uuid[PARTITION_META_INFO_UUIDLTH];
u8 volname[PARTITION_META_INFO_VOLNAMELTH];
};
--
2.53.0
^ permalink raw reply related
* [PATCH 12/19] x86: define DPS root partition type UUIDs
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
Dave Hansen, x86
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for the x86
32/64-bit variants described by the specification and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: x86@kernel.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/dps_root.h | 12 ++++++++++++
2 files changed, 13 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b875d2f27e48..6b6e7b56f972 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -82,6 +82,7 @@ config X86
select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_OPS if GART_IOMMU || XEN
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_EARLY_DEBUG if KGDB
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_EXECMEM_ROX if X86_64 && STRICT_MODULE_RWX
diff --git a/arch/x86/include/asm/dps_root.h b/arch/x86/include/asm/dps_root.h
new file mode 100644
index 000000000000..7c6ba5519d88
--- /dev/null
+++ b/arch/x86/include/asm/dps_root.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_X86_DPS_ROOT_H
+#define _ASM_X86_DPS_ROOT_H
+
+#ifdef CONFIG_X86_64
+#define DPS_ROOT_PARTITION_TYPE_UUID "4f68bce3-e8cd-4db1-96e7-fbcaf984b709"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "44479540-f297-41b2-9af7-d131d5f0458a"
+#endif
+
+#endif /* _ASM_X86_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 11/19] s390: define DPS root partition type UUIDs
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Heiko Carstens, Vasily Gorbik, Alexander Gordeev,
linux-s390
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for the s390
(32-bit) and s390x (64-bit) variants described by the specification and
select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/s390/Kconfig | 1 +
arch/s390/include/asm/dps_root.h | 12 ++++++++++++
2 files changed, 13 insertions(+)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 9921a3772bf7..af2cf67fffd7 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -91,6 +91,7 @@ config S390
select ARCH_HAS_DEBUG_WX
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_OPS if PCI
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORCE_DMA_UNENCRYPTED
select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/s390/include/asm/dps_root.h b/arch/s390/include/asm/dps_root.h
new file mode 100644
index 000000000000..e72e44a66097
--- /dev/null
+++ b/arch/s390/include/asm/dps_root.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_S390_DPS_ROOT_H
+#define _ASM_S390_DPS_ROOT_H
+
+#ifdef CONFIG_64BIT
+#define DPS_ROOT_PARTITION_TYPE_UUID "5eead9a9-fe09-4a1e-a1d7-520d00531306"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "08a7acea-624c-4a20-91e8-6e0fa67d23f9"
+#endif
+
+#endif /* _ASM_S390_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 10/19] riscv: define DPS root partition type UUIDs
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Paul Walmsley, Palmer Dabbelt, Albert Ou,
linux-riscv
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for the RISC-V
32/64-bit variants described by the specification and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/dps_root.h | 12 ++++++++++++
2 files changed, 13 insertions(+)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 1a2fadccd4c4..526be67e858a 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -28,6 +28,7 @@ config RISCV
select ARCH_HAS_DEBUG_VIRTUAL if MMU
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DEBUG_WX
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_ELF_CORE_EFLAGS if BINFMT_ELF && ELF_CORE
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/riscv/include/asm/dps_root.h b/arch/riscv/include/asm/dps_root.h
new file mode 100644
index 000000000000..86f8e1dbd6ad
--- /dev/null
+++ b/arch/riscv/include/asm/dps_root.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_RISCV_DPS_ROOT_H
+#define _ASM_RISCV_DPS_ROOT_H
+
+#ifdef CONFIG_64BIT
+#define DPS_ROOT_PARTITION_TYPE_UUID "72ec70a6-cf74-40e6-bd49-4bda08e8f224"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "60d5a7fe-8e7d-435c-b714-3dd8162144e1"
+#endif
+
+#endif /* _ASM_RISCV_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 09/19] powerpc: define DPS root partition type UUIDs
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Madhavan Srinivasan, Michael Ellerman,
linuxppc-dev
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for the powerpc
endian and 32/64-bit variants described by the specification and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/dps_root.h | 16 ++++++++++++++++
2 files changed, 17 insertions(+)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e93df95b79e7..e611280a6057 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -134,6 +134,7 @@ config PPC
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_DMA_MAP_DIRECT if PPC_PSERIES
select ARCH_HAS_DMA_OPS if PPC64
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_GCOV_PROFILE_ALL
select ARCH_HAS_GIGANTIC_PAGE if ARCH_SUPPORTS_HUGETLBFS
diff --git a/arch/powerpc/include/asm/dps_root.h b/arch/powerpc/include/asm/dps_root.h
new file mode 100644
index 000000000000..6b3592a73d3d
--- /dev/null
+++ b/arch/powerpc/include/asm/dps_root.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_POWERPC_DPS_ROOT_H
+#define _ASM_POWERPC_DPS_ROOT_H
+
+#ifdef CONFIG_PPC64
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+#define DPS_ROOT_PARTITION_TYPE_UUID "c31c45e6-3f39-412e-80fb-4809c4980599"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "912ade1d-a839-4913-8964-a10eee08fbd2"
+#endif
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "1de3f1ef-fa98-47b5-8dcd-4a860a654d78"
+#endif
+
+#endif /* _ASM_POWERPC_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 08/19] parisc: define DPS root partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, James E.J. Bottomley, Helge Deller, linux-parisc
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for parisc and
select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/dps_root.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index d3afac2f0d9b..94f0a758176a 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -24,6 +24,7 @@ config PARISC
select ARCH_STACKWALK
select ARCH_HAS_CACHE_LINE_SIZE
select ARCH_HAS_DEBUG_VM_PGTABLE
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select HAVE_RELIABLE_STACKTRACE
select RTC_CLASS
select RTC_DRV_GENERIC
diff --git a/arch/parisc/include/asm/dps_root.h b/arch/parisc/include/asm/dps_root.h
new file mode 100644
index 000000000000..bf475cd5b01c
--- /dev/null
+++ b/arch/parisc/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_PARISC_DPS_ROOT_H
+#define _ASM_PARISC_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "1aacdb3b-5444-4138-bd9e-e5c2239b2346"
+
+#endif /* _ASM_PARISC_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 07/19] mips: define DPS root partition type UUIDs
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Thomas Bogendoerfer, linux-mips
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for the MIPS
endian and 32/64-bit variants described by the specification and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/mips/Kconfig | 1 +
arch/mips/include/asm/dps_root.h | 20 ++++++++++++++++++++
2 files changed, 21 insertions(+)
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 4364f3dba688..15dd7d336cfa 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -10,6 +10,7 @@ config MIPS
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VIRTUAL if !64BIT
select ARCH_HAS_DMA_OPS if MACH_JAZZ
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_KCOV
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if !EVA
diff --git a/arch/mips/include/asm/dps_root.h b/arch/mips/include/asm/dps_root.h
new file mode 100644
index 000000000000..b07cab7399ad
--- /dev/null
+++ b/arch/mips/include/asm/dps_root.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_MIPS_DPS_ROOT_H
+#define _ASM_MIPS_DPS_ROOT_H
+
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+#ifdef CONFIG_64BIT
+#define DPS_ROOT_PARTITION_TYPE_UUID "700bda43-7a34-4507-b179-eeb93d7a7ca3"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "37c58c8a-d913-4156-a25f-48b1b64e07f0"
+#endif
+#else
+#ifdef CONFIG_64BIT
+#define DPS_ROOT_PARTITION_TYPE_UUID "d113af76-80ef-41b4-bdb6-0cff4d3d4a25"
+#else
+#define DPS_ROOT_PARTITION_TYPE_UUID "e9434544-6e2c-47cc-bae2-12d6deafb44c"
+#endif
+#endif
+
+#endif /* _ASM_MIPS_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 06/19] loongarch: define DPS root partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Huacai Chen, WANG Xuerui, loongarch
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for LoongArch64
and select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: loongarch@lists.linux.dev
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/dps_root.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 606597da46b8..64c27740b8a1 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -17,6 +17,7 @@ config LOONGARCH
select ARCH_HAS_CPU_FINALIZE_INIT
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DEBUG_VM_PGTABLE
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_KCOV
diff --git a/arch/loongarch/include/asm/dps_root.h b/arch/loongarch/include/asm/dps_root.h
new file mode 100644
index 000000000000..6022b60428ad
--- /dev/null
+++ b/arch/loongarch/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_LOONGARCH_DPS_ROOT_H
+#define _ASM_LOONGARCH_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "77055800-792c-4f94-b39a-98c91b762bb6"
+
+#endif /* _ASM_LOONGARCH_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 05/19] arm64: define DPS root partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Catalin Marinas, Will Deacon, linux-arm-kernel
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for arm64 and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/dps_root.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fe60738e5943..190f8dde63b2 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -26,6 +26,7 @@ config ARM64
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DMA_OPS if XEN
select ARCH_HAS_DMA_PREP_COHERENT
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
select ARCH_HAS_FAST_MULTIPLIER
select ARCH_HAS_FORTIFY_SOURCE
diff --git a/arch/arm64/include/asm/dps_root.h b/arch/arm64/include/asm/dps_root.h
new file mode 100644
index 000000000000..7344f9a52343
--- /dev/null
+++ b/arch/arm64/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_ARM64_DPS_ROOT_H
+#define _ASM_ARM64_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "b921b045-1df0-41c3-af44-4c6f280d3fae"
+
+#endif /* _ASM_ARM64_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 04/19] arm: define DPS root partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:09 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Russell King, linux-arm-kernel
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for ARM and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/dps_root.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 73e6647bea46..deedb5d808fb 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -14,6 +14,7 @@ config ARM
select ARCH_HAS_DMA_ALLOC if MMU
select ARCH_HAS_DMA_OPS
select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_ELF_RANDOMIZE
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_KEEPINITRD
diff --git a/arch/arm/include/asm/dps_root.h b/arch/arm/include/asm/dps_root.h
new file mode 100644
index 000000000000..e9f0f24bcac2
--- /dev/null
+++ b/arch/arm/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_ARM_DPS_ROOT_H
+#define _ASM_ARM_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "69dad710-2ce4-4e3c-b16c-21a1d49abed3"
+
+#endif /* _ASM_ARM_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 03/19] arc: define DPS root partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:08 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Vineet Gupta, linux-snps-arc
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for ARC and select
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/arc/Kconfig | 1 +
arch/arc/include/asm/dps_root.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 2ed7186c81c5..cc3a57a0111f 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -10,6 +10,7 @@ config ARC
select ARCH_HAS_CACHE_LINE_SIZE
select ARCH_HAS_DEBUG_VM_PGTABLE
select ARCH_HAS_DMA_PREP_COHERENT
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_SETUP_DMA_OPS
select ARCH_HAS_SYNC_DMA_FOR_CPU
diff --git a/arch/arc/include/asm/dps_root.h b/arch/arc/include/asm/dps_root.h
new file mode 100644
index 000000000000..c9db3ddf1a53
--- /dev/null
+++ b/arch/arc/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_ARC_DPS_ROOT_H
+#define _ASM_ARC_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "d27f46ed-2919-4cb8-bd25-9531f3c16534"
+
+#endif /* _ASM_ARC_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 02/19] alpha: define DPS root partition type UUID
From: Vincent Mailhol @ 2026-06-15 16:08 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Richard Henderson, Matt Turner, Magnus Lindholm,
linux-alpha
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns GPT partition type UUIDs to operating system partitions.
Root partitions use architecture-specific type UUIDs so the OS can
discover the intended root filesystem without relying on a root= cmdline
option.
Define DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h for alpha and
select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: linux-alpha@vger.kernel.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
arch/alpha/Kconfig | 1 +
arch/alpha/include/asm/dps_root.h | 8 ++++++++
2 files changed, 9 insertions(+)
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 7b7dafe7d9df..400cbb7525c8 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -5,6 +5,7 @@ config ALPHA
select ARCH_32BIT_USTAT_F_TINODE
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_DMA_OPS if PCI
+ select ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_MIGHT_HAVE_PC_SERIO
select ARCH_MODULE_NEEDS_WEAK_PER_CPU if SMP
diff --git a/arch/alpha/include/asm/dps_root.h b/arch/alpha/include/asm/dps_root.h
new file mode 100644
index 000000000000..7f70a83f72de
--- /dev/null
+++ b/arch/alpha/include/asm/dps_root.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ASM_ALPHA_DPS_ROOT_H
+#define _ASM_ALPHA_DPS_ROOT_H
+
+#define DPS_ROOT_PARTITION_TYPE_UUID "6523f8ae-3eb1-4e2a-a05a-18b695ae656f"
+
+#endif /* _ASM_ALPHA_DPS_ROOT_H */
--
2.53.0
^ permalink raw reply related
* [PATCH 01/19] init: add DPS root partition type UUID capability
From: Vincent Mailhol @ 2026-06-15 16:08 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol
In-Reply-To: <20260615-discoverable-root_partitions-v1-0-39c78fac42e2@kernel.org>
DPS [1] assigns native root partition type UUIDs per architecture.
Add the ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID config option so that
architectures can opt in.
Architectures that support this feature should define
DPS_ROOT_PARTITION_TYPE_UUID in asm/dps_root.h as a string
representation of the architecture's DPS root partition type UUID.
Add the hidden DPS_ROOT_AUTO_DISCOVERY symbol for the combination of
BLOCK, EFI and ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID, and use it to
expose DPS_ROOT_PARTITION_TYPE_UUID from the common linux/root_dev.h
header only when all prerequisites are met.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
include/linux/root_dev.h | 6 ++++++
init/Kconfig | 6 ++++++
2 files changed, 12 insertions(+)
diff --git a/include/linux/root_dev.h b/include/linux/root_dev.h
index 847c9a06101b..6b52a10b0bca 100644
--- a/include/linux/root_dev.h
+++ b/include/linux/root_dev.h
@@ -5,6 +5,12 @@
#include <linux/major.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
+#include <linux/uuid.h>
+
+#ifdef CONFIG_DPS_ROOT_AUTO_DISCOVERY
+#include <asm/dps_root.h>
+static_assert(sizeof(DPS_ROOT_PARTITION_TYPE_UUID) == UUID_STRING_LEN + 1);
+#endif
enum {
Root_NFS = MKDEV(UNNAMED_MAJOR, 255),
diff --git a/init/Kconfig b/init/Kconfig
index 147da6370bf0..982c6ad9da4d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -2287,6 +2287,12 @@ config ARCH_HAS_PREPARE_SYNC_CORE_CMD
config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
bool
+config ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
+ bool
+
+config DPS_ROOT_AUTO_DISCOVERY
+ def_bool BLOCK && EFI && ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID
+
# It may be useful for an architecture to override the definitions of the
# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
--
2.53.0
^ permalink raw reply related
* [PATCH 00/19] init: discoverable root partitions, a.k.a. an omittable "root=" cmdline option
From: Vincent Mailhol @ 2026-06-15 16:08 UTC (permalink / raw)
To: Jens Axboe, Davidlohr Bueso, Alexander Viro, Christian Brauner,
Jan Kara
Cc: linux-kernel, linux-block, linux-efi, linux-fsdevel,
Vincent Mailhol, Richard Henderson, Matt Turner, Magnus Lindholm,
linux-alpha, Vineet Gupta, linux-snps-arc, Russell King,
linux-arm-kernel, Catalin Marinas, Will Deacon, Huacai Chen,
WANG Xuerui, loongarch, Thomas Bogendoerfer, linux-mips,
James E.J. Bottomley, Helge Deller, linux-parisc,
Madhavan Srinivasan, Michael Ellerman, linuxppc-dev,
Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv,
Heiko Carstens, Vasily Gorbik, Alexander Gordeev, linux-s390,
Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen, x86,
Jonathan Corbet, Shuah Khan, linux-doc
DPS [1] defines GPT partition type UUIDs for OS partitions and
attributes that control whether such partitions should be
automatically discovered. The specification states that:
The OS can discover and mount the necessary file systems with a
non-existent or incomplete /etc/fstab file and without the root=
kernel command line option.
DPS is already implemented in systemd-gpt-auto-generator [2], which,
when embedded in an initrd, indeed allows automatic detection of the
root filesystem through its partition type UUID.
This series adds this discovery feature directly into the kernel so
that people who are not using systemd or not using an initrd can still
benefit from it. The implementation follows the same model as
systemd-gpt-auto-generator:
- GPT partition type UUIDs are used for automatic discovery policy
only. No root=PARTTYPEUUID=xxx cmdline option or similar syntax is
added.
- The root= cmdline option takes precedence. This prevents unexpected
behaviour.
- Only the disk with the active EFI System Partition is scanned, as
required by DPS. The disk is identified through the Boot Loader
Interface LoaderDevicePartUUID EFI variable.
The DPS no-auto attribute is also implemented, giving another option for
the user to disable this auto discovery. However, the DPS read-only
attribute is intentionally not enforced. The kernel already mounts the
root filesystem read-only by default unless the command line requests
rw, and user space remains responsible for deciding whether a discovered
root should later be remounted read-write based on DPS metadata and
local policy. The other partition type UUIDs (home, swap, var...) are
also out of scope for the same reason: user space remains responsible
for mounting anything other than the root partition.
Patch 1 adds the ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID capability and
the hidden CONFIG_DPS_ROOT_AUTO_DISCOVERY Kconfig symbol used to signal
whether the feature is available. Patches 2 to 12 declare the
ARCH_HAS_DPS_ROOT_PARTITION_TYPE_UUID capability for the supported
architectures and define their architecture-specific root partition type
UUID values in asm/dps_root.h.
Patches 13 to 16 make the GPT partition type UUID and the no-auto
attribute available during early block lookup.
Patch 17 is a small code refactor that prepares for patch 18, which
updates the root mount path so that, when root= is omitted, the kernel
reads LoaderDevicePartUUID and uses the early block lookup
infrastructure to discover the DPS root partition on that disk.
Finally, patch 19 documents this automatic root discovery feature.
Tested with GRUB, which implements the LoaderDevicePartUUID EFI variable
in its bli module [3]. With this, I was able to boot a kernel with a
completely empty cmdline and no initrd.
[1] The Discoverable Partitions Specification (DPS)
Link: https://uapi-group.org/specifications/specs/discoverable_partitions_specification/
[2] systemd-gpt-auto-generator
Link: https://www.freedesktop.org/software/systemd/man/latest/systemd-gpt-auto-generator.html
[3] GRUB -- §16.2 bli
Link: https://www.gnu.org/software/grub/manual/grub/html_node/bli_005fmodule.html
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
Vincent Mailhol (19):
init: add DPS root partition type UUID capability
alpha: define DPS root partition type UUID
arc: define DPS root partition type UUID
arm: define DPS root partition type UUID
arm64: define DPS root partition type UUID
loongarch: define DPS root partition type UUID
mips: define DPS root partition type UUIDs
parisc: define DPS root partition type UUID
powerpc: define DPS root partition type UUIDs
riscv: define DPS root partition type UUIDs
s390: define DPS root partition type UUIDs
x86: define DPS root partition type UUIDs
block: store GPT partition type UUID
block: add early_lookup_bdev_by_type_uuid()
block: store GPT attributes as a raw value
block: don't discover partition with DPS no-auto GPT attribute
init: factor out root device lookup into lookup_root_device()
init: discover root by DPS partition type UUID
docs: document discoverable root partitions
Documentation/admin-guide/discoverable-root.rst | 33 +++++++++
Documentation/admin-guide/index.rst | 1 +
Documentation/admin-guide/kernel-parameters.txt | 5 ++
arch/alpha/Kconfig | 1 +
arch/alpha/include/asm/dps_root.h | 8 +++
arch/arc/Kconfig | 1 +
arch/arc/include/asm/dps_root.h | 8 +++
arch/arm/Kconfig | 1 +
arch/arm/include/asm/dps_root.h | 8 +++
arch/arm64/Kconfig | 1 +
arch/arm64/include/asm/dps_root.h | 8 +++
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/dps_root.h | 8 +++
arch/mips/Kconfig | 1 +
arch/mips/include/asm/dps_root.h | 20 ++++++
arch/parisc/Kconfig | 1 +
arch/parisc/include/asm/dps_root.h | 8 +++
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/dps_root.h | 16 +++++
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/dps_root.h | 12 ++++
arch/s390/Kconfig | 1 +
arch/s390/include/asm/dps_root.h | 12 ++++
arch/x86/Kconfig | 1 +
arch/x86/include/asm/dps_root.h | 12 ++++
block/blk.h | 1 +
block/early-lookup.c | 68 +++++++++++++++++-
block/partitions/core.c | 2 +
block/partitions/efi.c | 3 +
block/partitions/efi.h | 11 ++-
include/linux/blk_types.h | 1 +
include/linux/blkdev.h | 5 ++
include/linux/root_dev.h | 6 ++
init/Kconfig | 6 ++
init/do_mounts.c | 94 ++++++++++++++++++++++++-
35 files changed, 355 insertions(+), 12 deletions(-)
---
base-commit: 36808d5e983985bbda87e01059cccc071fe3ec8d
change-id: 20260611-discoverable-root_partitions-bdacbada570d
Best regards,
--
Vincent Mailhol <mailhol@kernel.org>
^ permalink raw reply
* Re: Repeatable, raid1+O_DIRECT, hang/warn
From: Keith Busch @ 2026-06-15 15:35 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: linux-block, dm-devel
In-Reply-To: <ajAYN_mmjzYBAimV@kbusch-mbp>
On Mon, Jun 15, 2026 at 09:20:23AM -0600, Keith Busch wrote:
> On Sun, Jun 14, 2026 at 05:57:48PM +0000, Dr. David Alan Gilbert wrote:
> > Jun 14 18:08:32 dalek kernel: device-mapper: raid1: Mirror read failed from 252:24. Trying alternative device.
> > Jun 14 18:08:32 dalek kernel: ------------[ cut here ]------------
> > Jun 14 18:08:32 dalek dmeventd[1010]: Primary mirror device 252:24 read failed.
> > Jun 14 18:08:32 dalek kernel: WARNING: block/bio.c:1044 at bio_add_page+0x18b/0x250, CPU#15: kworker/15:1/369
> > Jun 14 18:08:32 dalek dmeventd[1010]: main-lvol0 is now in-sync.
> > Jun 14 18:08:32 dalek kernel: Modules linked in: nft_masq nft_reject_ipv4 act_csum cls_u32 sch_htb nf_nat_tftp nf_conntrack_tftp bridge stp llc rfkill nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reje>
> > Jun 14 18:08:32 dalek kernel: drm_panel_backlight_quirks gpu_sched drm_suballoc_helper video nvme drm_display_helper nvme_core cec nvme_keyring sp5100_tco nvme_auth wmi serio_raw fuse scsi_dh_alua i2c_dev scsi_dh_rdac scsi_dh_emc
> > Jun 14 18:08:32 dalek kernel: CPU: 15 UID: 0 PID: 369 Comm: kworker/15:1 Not tainted 7.1.0-rc7+ #786 PREEMPT(lazy)
> > Jun 14 18:08:32 dalek kernel: Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X570 Pro4, BIOS P3.10 07/13/2020
> > Jun 14 18:08:32 dalek kernel: Workqueue: kmirrord do_mirror
> > Jun 14 18:08:32 dalek kernel: RIP: 0010:bio_add_page+0x18b/0x250
> > Jun 14 18:08:32 dalek kernel: Code: 24 10 4c 8b 04 24 84 c0 0f 85 c9 00 00 00 41 0f b7 40 78 48 8b 74 24 08 8b 4c 24 14 e9 b4 fe ff ff 0f 0b 31 c0 e9 55 d1 af 00 <0f> 0b eb f5 48 8b 7f 08 83 7f 60 05 0f 85 00 ff ff ff 49 8b 3b 4c
> > Jun 14 18:08:32 dalek kernel: RSP: 0018:ffffd1fb8176fc10 EFLAGS: 00010246
> > Jun 14 18:08:32 dalek kernel: RAX: 0000000000000000 RBX: ffffd1fb8176fd18 RCX: 0000000000000000
> > Jun 14 18:08:32 dalek kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8d1a8eb28b00
> > Jun 14 18:08:32 dalek kernel: RBP: 0000000000000000 R08: ffffd1fb8176fc38 R09: ffffd1fb8176fc40
> > Jun 14 18:08:32 dalek kernel: R10: ffffd1fb8176fc34 R11: 0000000000000000 R12: 0000000000000000
> > Jun 14 18:08:32 dalek kernel: R13: ffffd1fb8176fd90 R14: 0000000000000001 R15: ffff8d1a8eb28b00
> > Jun 14 18:08:32 dalek kernel: FS: 0000000000000000(0000) GS:ffff8d29d161f000(0000) knlGS:0000000000000000
> > Jun 14 18:08:32 dalek kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > Jun 14 18:08:32 dalek kernel: CR2: 00007f0ddcd7b9d0 CR3: 000000023dcbf000 CR4: 0000000000350ef0
> > Jun 14 18:08:32 dalek kernel: Call Trace:
> > Jun 14 18:08:32 dalek kernel: <TASK>
> > Jun 14 18:08:32 dalek kernel: do_region+0x227/0x2a0
>
> I think the problem is that do_region is tracking the "remaining" in
> sector granularity, but devices can have dma alignment such that it's
> valid to have sub-sector vectors. Rounding the length appended
> to_sectors() creates a 0 length subtraction, so the loop thinks no
> progress is made and loops forever. If we track it in bytes instead of
> sectors, then that should fix this observation.
I recreated your observation and this patch below appears to fix the
stuck behavior.
---
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c
index 1db565b376200..d72b9331c2fd1 100644
--- a/drivers/md/dm-io.c
+++ b/drivers/md/dm-io.c
@@ -362,19 +362,26 @@ static void do_region(const blk_opf_t opf, unsigned int region,
bio->bi_iter.bi_size = num_sectors << SECTOR_SHIFT;
remaining -= num_sectors;
} else {
- while (remaining) {
+ unsigned long byte_remaining = to_bytes(remaining);
+
+ while (byte_remaining) {
/*
* Try and add as many pages as possible.
*/
dp->get_page(dp, &page, &len, &offset);
- len = min(len, to_bytes(remaining));
+ len = min(len, byte_remaining);
if (!bio_add_page(bio, page, len, offset))
break;
offset = 0;
- remaining -= to_sector(len);
+ byte_remaining -= len;
dp->next_page(dp);
}
+ remaining = to_sector(byte_remaining);
}
atomic_inc(&io->count);
--
^ permalink raw reply related
* [GIT PULL] Block updates for 7.2
From: Jens Axboe @ 2026-06-15 15:24 UTC (permalink / raw)
To: Linus Torvalds; +Cc: linux-block@vger.kernel.org
Hi Linus,
Here are the block updates queued up for the 7.2 merge window. This
contains:
- NVMe pull request via Keith:
- Per-controller admin and IO timeout sysfs attributes, and
letting the block layer set request timeouts (Maurizio,
Maximilian)
- Multipath passthrough iostats, and PCI P2PDMA enablement for
multipath devices (Keith, Kiran)
- A new diag sysfs attribute group exporting per-controller
counters (retries, multipath failover, error counters, requeue
and failure counts, reset and reconnect events) (Nilay)
- FDP configuration validation and bounds check fixes (liuxixin)
- Various nvmet fixes, including a pre-auth out-of-bounds read in
the Discovery Get Log Page handler, auth payload bounds
validation, and tcp error-path leak fixes (Bryam, Tianchu,
Geliang)
- nvme-tcp lockdep and workqueue fixes (Shin'ichiro, Kuniyuki,
Eric)
- Assorted other fixes and cleanups (John, Yao, Chao, Mateusz,
Achkinazi, Wentao)
- MD pull request via Yu Kuai:
- raid1/raid10 fixes for a deadlock in the read error recovery
path, error-path detection and bio accounting with cloned bios,
and an nr_pending leak in the REQ_ATOMIC bad-block error path
(Abd-Alrhman)
- PCI P2PDMA propagation from member devices to the RAID device
(Kiran)
- dm-raid bio requeue fix, and various smaller fixes and cleanups
(Benjamin, Chen, Li, Thorsten)
- Enable Clang lock context analysis for the block layer, with the
accompanying annotations across queue limits, the blk_holder_ops
callbacks, crypto, cgroup, iocost, kyber and mq-deadline (Bart)
- Block status code infrastructure work: a tagged status table, a
str_to_blk_op() helper, a bio_endio_status() helper, and on top of
that a new configurable block-layer error injection facility (Christoph)
- DRBD netlink rework, replacing the genl_magic machinery with explicit
netlink serialization and moving the DRBD UAPI headers to
include/uapi/linux/ (Christoph Böhmwalder)
- bvec improvements: a bvec_folio() helper and making the bvec_iter
helpers proper inline functions (Willy, Christoph)
- ublk cleanups and a canceling-flag fix for the disk-not-allocated
case (Caleb, Ming)
- Partition handling fixes: bound the AIX pp_count scan, fix an of_node
refcount leak, and replace __get_free_page() with kmalloc() (Bryam,
Wentao, Mike)
- Convert numa_node to int in blk_mq_hw_ctx and ->init_request, and add
WQ_PERCPU to the block workqueue users (Mateusz, Marco)
- Block statistics and tracing: propagate in-flight to the whole disk
on partition IO, export passthrough stats, and a new
block_rq_tag_wait tracepoint (Tang, Keith, Aaron)
- A round of removals, unexports and cleanups across bio, direct-io and
the bvec helpers (Christoph)
- Various driver fixes (mtip32xx use-after-free, rbd snap_count
validation and strscpy conversion, nbd socket lockdep reclassify,
virtio-blk zone report clamp, floppy) and a batch of MAINTAINERS
email/list updates (Coly, Li, Yu, Christoph Böhmwalder)
- Other little fixes and cleanups all over
Please pull!
The following changes since commit 7fd2df204f342fc17d1a0bfcd474b24232fb0f32:
Linux 7.1-rc2 (2026-05-03 14:21:25 -0700)
are available in the Git repository at:
https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux.git tags/for-7.2/block-20260615
for you to fetch changes up to c7c76f9232bd34835d821f14abdc5fafc17bc938:
MAINTAINERS: Update Coly Li's email address (2026-06-13 09:29:02 -0600)
----------------------------------------------------------------
for-7.2/block-20260615
----------------------------------------------------------------
Aaron Tomlin (1):
blk-mq: add tracepoint block_rq_tag_wait
Abd-Alrhman Masalkhi (5):
md: skip redundant raid_disks update when value is unchanged
md/raid1,raid10: fix deadlock in read error recovery path
md/raid1,raid10: fix error-path detection with md_cloned_bio()
md/raid1,raid10: fix bio accounting for split md cloned bios
raid1: fix nr_pending leak in REQ_ATOMIC bad-block error path
Achkinazi, Igor (1):
nvme-multipath: set BIO_REMAPPED on bios remapped to per-path namespace disks
Andreas Hindborg (1):
rust: block: mq: align init_request numa_node arg with C signature
Bart Van Assche (14):
block: Annotate the queue limits functions
block/bdev: Annotate the blk_holder_ops callback functions
block/cgroup: Split blkg_conf_prep()
block/cgroup: Split blkg_conf_exit()
block/cgroup: Improve lock context annotations
block/blk-iocost: Combine two error paths in ioc_qos_write()
block/cgroup: Inline blkg_conf_{open,close}_bdev_frozen()
block/crypto: Annotate the crypto functions
block/blk-iocost: Split ioc_rqos_throttle()
block/blk-iocost: Inline iocg_lock() and iocg_unlock()
block/blk-mq-debugfs: Improve lock context annotations
block/Kyber: Make the lock context annotations compatible with Clang
block/mq-deadline: Make the lock context annotations compatible with Clang
block: Enable lock context analysis
Benjamin Marzinski (1):
dm-raid: only requeue bios when dm is suspending
Bryam Vargas (2):
nvmet: fix pre-auth out-of-bounds heap read in Discovery Get Log Page
partitions: aix: bound the pp_count scan to the ppe array
Caleb Sander Mateos (4):
blk-mq: introduce blk_rq_has_data()
ublk: optimize ublk_rq_has_data()
ublk: move ublk_req_build_flags() earlier
ublk: factor out ublk_init_iod() helper
Chaitanya Kulkarni (1):
block: clear BLK_FEAT_PCI_P2PDMA in blk_stack_limits() for non-supporting devices
Chao Shi (2):
nvme: core: reject invalid LBA data size from Identify Namespace
block: skip sync_blockdev() on surprise removal in bdev_mark_dead()
Chen Cheng (1):
md/raid10: reset read_slot when reusing r10bio for discard
Christoph Böhmwalder (4):
drbd: move UAPI headers to include/uapi/linux/
drbd: replace genl_magic with explicit netlink serialization
drbd: clean up UAPI headers
MAINTAINERS: use new drbd-dev mailing list
Christoph Hellwig (18):
block: remove zero_fill_bio_iter
block: remove bio_copy_data_iter
block: unexport blk_io_schedule
block: unexport blk_status_to_str
block: unexport bio_{set,check}_pages_dirty
direct-io: remove IOCB_NOWAIT support
block: don't set BIO_QUIET for BLK_STS_AGAIN
block: mark biovec_init_pool static
loop: cleanup lo_rw_aio
nvme-tcp: cleanup nvme_tcp_init_iter
bvec: make the bvec_iter helpers inline functions
block: add a bio_endio_status helper
md/raid1: cleanup handle_read_error
md/raid1: move the exceed_read_errors condition out of fix_read_error
block: add a macro to initialize the status table
block: add a "tag" for block status codes
block: add a str_to_blk_op helper
block: add configurable error injection
Coly Li (1):
MAINTAINERS: Update Coly Li's email address
David Laight (1):
drivers/block/rbd: Use strscpy() to copy strings into arrays
Denis Arefev (1):
block: Avoid mounting the bdev pseudo-filesystem in userspace
Eric Dumazet (1):
nbd: Reclassify sockets to avoid lockdep circular dependency
Geliang Tang (2):
nvmet-tcp: fix page fragment cache leak in error path
nvmet-tcp: check return value of nvmet_tcp_set_queue_sock
Haoze Xie (1):
rust: block: fix GenDisk cleanup paths
Jens Axboe (2):
Merge tag 'md-7.2-20260531' of https://git.kernel.org/pub/scm/linux/kernel/git/mdraid/linux into for-7.2/block
Merge tag 'nvme-7.2-2026-06-04' of git://git.infradead.org/nvme into for-7.2/block
John Garry (2):
nvme: use DEFINE_SIMPLE_SYSFS_GROUP_VISIBLE for multipath_sysfs
nvme-multipath: pass NS head to nvme_mpath_revalidate_paths()
Keith Busch (3):
block: export passthrough stats enabled
nvme: add support multipath passthrough iostats
block: check bio split for unaligned bvec
Kiran Kumar Modukuri (2):
md: propagate BLK_FEAT_PCI_P2PDMA from member devices to RAID device
nvme-multipath: enable PCI P2PDMA for multipath devices
Kuniyuki Iwashima (1):
nvme-tcp: Use WQ_PERCPU explicitly if wq_unbound is false.
Li Nan (1):
MAINTAINERS: Update Li Nan's E-mail address
Marco Crivellari (1):
block: Add WQ_PERCPU to alloc_workqueue users
Mateusz Nowicki (2):
block: switch numa_node to int in blk_mq_hw_ctx and init_request
nvme-pci: fix out-of-bounds access in nvme_setup_descriptor_pools
Matthew Wilcox (Oracle) (2):
block: Add bvec_folio()
block: Include bvec.h kernel-doc in the htmldocs
Maurizio Lombardi (7):
nvme: remove redundant timeout argument from nvme_wait_freeze_timeout
nvme: add sysfs attribute to change admin timeout per nvme controller
nvme: add sysfs attribute to change IO timeout per controller
nvme-core: align fabrics_q teardown with admin_q in nvme_free_ctrl
nvmet-loop: do not alloc admin tag set during reset
nvme-core: warn on allocating admin tag set with existing queue
nvme-core: fix unsigned comparison warning in nvme_wait_freeze_timeout
Maximilian Heyne (1):
nvme: Let the blocklayer set timeouts for requests
Michael Bommarito (1):
virtio-blk: clamp zone report to the report buffer capacity
Mike Rapoport (Microsoft) (1):
block: partitions: replace __get_free_page() with kmalloc()
Ming Lei (1):
ublk: set canceling flag even when disk is not allocated
Nilay Shroff (9):
nvme-multipath: fix flex array size in struct nvme_ns_head
nvme: add diag attribute group under sysfs
nvme: export command retry count via sysfs
nvme: export multipath failover count via sysfs
nvme: export command error counters via sysfs
nvme: export I/O requeue count when no path is usable via sysfs
nvme: export I/O failure count when no path is available via sysfs
nvme: export controller reset event count via sysfs
nvme: export controller reconnect event count via sysfs
Rosen Penev (1):
rbd: check snap_count against RBD_MAX_SNAP_COUNT
Shin'ichiro Kawasaki (2):
nvme-tcp: move nvme_tcp_reclassify_socket()
nvme-tcp: lockdep: use dynamic lockdep keys per socket instance
Steven Feng (1):
block: optimize I/O merge hot path with unlikely() hints
Tal Zussman (1):
block: remove blkdev_write_begin() and blkdev_write_end()
Tang Yizhou (1):
block: propagate in_flight to whole disk on partition I/O
Tao Cui (1):
blk-throttle: schedule parent dispatch in tg_flush_bios()
Thorsten Blum (3):
md/raid0: use str_plural helper in dump_zones
block/partitions/acorn: use min in {riscix,linux}_partition
n64cart: use strscpy in n64cart_probe
Tianchu Chen (1):
nvmet-auth: validate reply message payload bounds against transfer length
Uwe Kleine-König (The Capable Hub) (1):
floppy: Drop unused pnp driver data
Wentao Liang (2):
block: partitions: fix of_node refcount leak in of_partition()
nvme: target: rdma: fix ndev refcount leak on queue connect
Yao Sang (1):
nvme: refresh multipath head zoned limits from path limits
Yu Kuai (2):
MAINTAINERS: update Yu Kuai's email address
block, bfq: release cgroup stats with bfq_group
Yuho Choi (1):
mtip32xx: fix use-after-free on service thread failure
liuxixin (2):
nvme: fix FDP fdpcidx bounds check
nvme: validate FDP configuration descriptor sizes
liyouhong (1):
nvme-multipath: require exact iopolicy names for module parameter
Documentation/block/error-injection.rst | 59 +
Documentation/block/index.rst | 1 +
Documentation/core-api/kernel-api.rst | 1 +
MAINTAINERS | 10 +-
block/Kconfig | 8 +
block/Makefile | 3 +
block/bdev.c | 13 +-
block/bfq-cgroup.c | 54 +-
block/bio.c | 52 +-
block/blk-cgroup.c | 98 +-
block/blk-cgroup.h | 13 +-
block/blk-core.c | 104 +-
block/blk-crypto-fallback.c | 9 +-
block/blk-crypto-profile.c | 2 +
block/blk-crypto.c | 3 +-
block/blk-iocost.c | 306 ++-
block/blk-iolatency.c | 19 +-
block/blk-merge.c | 17 +-
block/blk-mq-debugfs.c | 24 +-
block/blk-mq-tag.c | 6 +
block/blk-mq.c | 43 +-
block/blk-settings.c | 2 +
block/blk-sysfs.c | 5 +
block/blk-throttle.c | 85 +-
block/blk-zoned.c | 2 +-
block/blk.h | 32 +
block/bsg-lib.c | 2 +-
block/error-injection.c | 315 +++
block/error-injection.h | 21 +
block/fops.c | 27 +-
block/genhd.c | 4 +
block/kyber-iosched.c | 7 +-
block/mq-deadline.c | 12 +-
block/partitions/acorn.c | 5 +-
block/partitions/aix.c | 9 +
block/partitions/core.c | 6 +-
block/partitions/of.c | 5 +-
drivers/block/drbd/Makefile | 1 +
drivers/block/drbd/drbd_buildtag.c | 2 +-
.../linux => drivers/block/drbd}/drbd_config.h | 0
drivers/block/drbd/drbd_debugfs.c | 2 +-
drivers/block/drbd/drbd_int.h | 6 +-
drivers/block/drbd/drbd_main.c | 6 +-
drivers/block/drbd/drbd_nl.c | 416 ++--
drivers/block/drbd/drbd_nl_gen.c | 2606 ++++++++++++++++++++
drivers/block/drbd/drbd_nl_gen.h | 395 +++
drivers/block/drbd/drbd_proc.c | 2 +-
drivers/block/floppy.c | 4 +-
drivers/block/loop.c | 24 +-
drivers/block/mtip32xx/mtip32xx.c | 19 +-
drivers/block/n64cart.c | 3 +-
drivers/block/nbd.c | 39 +-
drivers/block/rbd.c | 9 +-
drivers/block/ublk_drv.c | 174 +-
drivers/block/virtio_blk.c | 2 +
drivers/md/dm-raid.c | 6 +
drivers/md/dm-rq.c | 2 +-
drivers/md/md.c | 32 +-
drivers/md/md.h | 7 +
drivers/md/raid0.c | 4 +-
drivers/md/raid1.c | 64 +-
drivers/md/raid10.c | 30 +-
drivers/md/raid5.c | 7 +-
drivers/mmc/core/queue.c | 2 +-
drivers/mtd/ubi/block.c | 2 +-
drivers/nvme/host/apple.c | 4 +-
drivers/nvme/host/core.c | 74 +-
drivers/nvme/host/fc.c | 5 +-
drivers/nvme/host/ioctl.c | 9 +
drivers/nvme/host/multipath.c | 144 +-
drivers/nvme/host/nvme.h | 21 +-
drivers/nvme/host/pci.c | 16 +-
drivers/nvme/host/rdma.c | 6 +-
drivers/nvme/host/sysfs.c | 311 ++-
drivers/nvme/host/tcp.c | 127 +-
drivers/nvme/target/discovery.c | 23 +-
drivers/nvme/target/fabrics-cmd-auth.c | 15 +-
drivers/nvme/target/loop.c | 33 +-
drivers/nvme/target/rdma.c | 6 +-
drivers/nvme/target/tcp.c | 11 +-
drivers/scsi/scsi_lib.c | 2 +-
fs/direct-io.c | 15 +-
include/linux/bio.h | 32 +-
include/linux/blk-mq.h | 53 +-
include/linux/blkdev.h | 28 +-
include/linux/bvec.h | 112 +-
include/linux/drbd_genl.h | 536 ----
include/linux/drbd_genl_api.h | 56 -
include/linux/genl_magic_func.h | 413 ----
include/linux/genl_magic_struct.h | 272 --
include/trace/events/block.h | 59 +
include/{ => uapi}/linux/drbd.h | 73 +-
include/uapi/linux/drbd_genl.h | 359 +++
include/{ => uapi}/linux/drbd_limits.h | 10 +-
io_uring/rsrc.c | 2 +-
mm/page_io.c | 4 +-
rust/kernel/block/mq/gen_disk.rs | 20 +-
rust/kernel/block/mq/operations.rs | 2 +-
98 files changed, 5781 insertions(+), 2322 deletions(-)
create mode 100644 Documentation/block/error-injection.rst
create mode 100644 block/error-injection.c
create mode 100644 block/error-injection.h
rename {include/linux => drivers/block/drbd}/drbd_config.h (100%)
create mode 100644 drivers/block/drbd/drbd_nl_gen.c
create mode 100644 drivers/block/drbd/drbd_nl_gen.h
delete mode 100644 include/linux/drbd_genl.h
delete mode 100644 include/linux/drbd_genl_api.h
delete mode 100644 include/linux/genl_magic_func.h
delete mode 100644 include/linux/genl_magic_struct.h
rename include/{ => uapi}/linux/drbd.h (85%)
create mode 100644 include/uapi/linux/drbd_genl.h
rename include/{ => uapi}/linux/drbd_limits.h (97%)
--
Jens Axboe
^ permalink raw reply
* Re: Repeatable, raid1+O_DIRECT, hang/warn
From: Keith Busch @ 2026-06-15 15:20 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: linux-block, dm-devel
In-Reply-To: <ai7rnH20IYeSmY8s@gallifrey>
On Sun, Jun 14, 2026 at 05:57:48PM +0000, Dr. David Alan Gilbert wrote:
> Jun 14 18:08:32 dalek kernel: device-mapper: raid1: Mirror read failed from 252:24. Trying alternative device.
> Jun 14 18:08:32 dalek kernel: ------------[ cut here ]------------
> Jun 14 18:08:32 dalek dmeventd[1010]: Primary mirror device 252:24 read failed.
> Jun 14 18:08:32 dalek kernel: WARNING: block/bio.c:1044 at bio_add_page+0x18b/0x250, CPU#15: kworker/15:1/369
> Jun 14 18:08:32 dalek dmeventd[1010]: main-lvol0 is now in-sync.
> Jun 14 18:08:32 dalek kernel: Modules linked in: nft_masq nft_reject_ipv4 act_csum cls_u32 sch_htb nf_nat_tftp nf_conntrack_tftp bridge stp llc rfkill nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reje>
> Jun 14 18:08:32 dalek kernel: drm_panel_backlight_quirks gpu_sched drm_suballoc_helper video nvme drm_display_helper nvme_core cec nvme_keyring sp5100_tco nvme_auth wmi serio_raw fuse scsi_dh_alua i2c_dev scsi_dh_rdac scsi_dh_emc
> Jun 14 18:08:32 dalek kernel: CPU: 15 UID: 0 PID: 369 Comm: kworker/15:1 Not tainted 7.1.0-rc7+ #786 PREEMPT(lazy)
> Jun 14 18:08:32 dalek kernel: Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X570 Pro4, BIOS P3.10 07/13/2020
> Jun 14 18:08:32 dalek kernel: Workqueue: kmirrord do_mirror
> Jun 14 18:08:32 dalek kernel: RIP: 0010:bio_add_page+0x18b/0x250
> Jun 14 18:08:32 dalek kernel: Code: 24 10 4c 8b 04 24 84 c0 0f 85 c9 00 00 00 41 0f b7 40 78 48 8b 74 24 08 8b 4c 24 14 e9 b4 fe ff ff 0f 0b 31 c0 e9 55 d1 af 00 <0f> 0b eb f5 48 8b 7f 08 83 7f 60 05 0f 85 00 ff ff ff 49 8b 3b 4c
> Jun 14 18:08:32 dalek kernel: RSP: 0018:ffffd1fb8176fc10 EFLAGS: 00010246
> Jun 14 18:08:32 dalek kernel: RAX: 0000000000000000 RBX: ffffd1fb8176fd18 RCX: 0000000000000000
> Jun 14 18:08:32 dalek kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8d1a8eb28b00
> Jun 14 18:08:32 dalek kernel: RBP: 0000000000000000 R08: ffffd1fb8176fc38 R09: ffffd1fb8176fc40
> Jun 14 18:08:32 dalek kernel: R10: ffffd1fb8176fc34 R11: 0000000000000000 R12: 0000000000000000
> Jun 14 18:08:32 dalek kernel: R13: ffffd1fb8176fd90 R14: 0000000000000001 R15: ffff8d1a8eb28b00
> Jun 14 18:08:32 dalek kernel: FS: 0000000000000000(0000) GS:ffff8d29d161f000(0000) knlGS:0000000000000000
> Jun 14 18:08:32 dalek kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> Jun 14 18:08:32 dalek kernel: CR2: 00007f0ddcd7b9d0 CR3: 000000023dcbf000 CR4: 0000000000350ef0
> Jun 14 18:08:32 dalek kernel: Call Trace:
> Jun 14 18:08:32 dalek kernel: <TASK>
> Jun 14 18:08:32 dalek kernel: do_region+0x227/0x2a0
I think the problem is that do_region is tracking the "remaining" in
sector granularity, but devices can have dma alignment such that it's
valid to have sub-sector vectors. Rounding the length appended
to_sectors() creates a 0 length subtraction, so the loop thinks no
progress is made and loops forever. If we track it in bytes instead of
sectors, then that should fix this observation.
^ permalink raw reply
* Re: [PATCH v3 3/4] iomap: reject NOWAIT and BOUNCE direct IOs
From: Christoph Hellwig @ 2026-06-15 15:05 UTC (permalink / raw)
To: Qu Wenruo; +Cc: linux-btrfs, linux-block, linux-fsdevel, linux-xfs
In-Reply-To: <3d739b6dc37e34ca2a2a3780d12d0288a4060d57.1781253428.git.wqu@suse.com>
On Fri, Jun 12, 2026 at 07:21:14PM +0930, Qu Wenruo wrote:
> If a direct IO requires bounced pages for stable buffer, it will always
> allocate memory, and both bio_iov_iter_bounce_write() and
> bio_iov_iter_bounce_read() are allocating pages using GFP_KERNEL, which
> can sleep and break NOWAIT requirement.
>
> So we need to reject such NOWAIT and BOUNCE direct IO in
> iomap_dio_bio_iter().
That's a bit heavy handed. Just do a noretry allocation.
^ permalink raw reply
* Re: [PATCH v3 2/4] block: respect iov_iter::nofault flag in bio_iov_iter_bounce_write()
From: Christoph Hellwig @ 2026-06-15 15:05 UTC (permalink / raw)
To: Qu Wenruo; +Cc: linux-btrfs, linux-block, linux-fsdevel, linux-xfs
In-Reply-To: <35a61301ea76c71d101533bf7d4aeffb7752fb85.1781253428.git.wqu@suse.com>
On Fri, Jun 12, 2026 at 07:21:13PM +0930, Qu Wenruo wrote:
> diff --git a/block/bio.c b/block/bio.c
> index b33ff69bb722..01bb76d9717c 100644
> --- a/block/bio.c
> +++ b/block/bio.c
> @@ -1335,7 +1335,10 @@ static int bio_iov_iter_bounce_write(struct bio *bio, struct iov_iter *iter,
> break;
> bio_add_folio_nofail(bio, folio, this_len, 0);
>
> - copied = copy_from_iter(folio_address(folio), this_len, iter);
> + if (iter->nofault)
> + copied = copy_folio_from_iter_atomic(folio, 0, this_len, iter);
Same here, please keep a sane line length.
^ permalink raw reply
* Re: [PATCH v3 1/4] block: revert the iov_iter after a short copy in bio_iov_iter_bounce_write()
From: Christoph Hellwig @ 2026-06-15 15:03 UTC (permalink / raw)
To: Qu Wenruo; +Cc: linux-btrfs, linux-block, linux-fsdevel, linux-xfs
In-Reply-To: <ed47077f3d4336b64a177486e74b4f6a460b2392.1781253428.git.wqu@suse.com>
On Fri, Jun 12, 2026 at 07:21:12PM +0930, Qu Wenruo wrote:
> + copied = copy_from_iter(folio_address(folio), this_len, iter);
> + if (copied < this_len) {
> + iov_iter_revert(iter, bio->bi_iter.bi_size - this_len + copied);
Please keep the line below 80 characters. And maybe add the explanation
for the amount reverted here based on what you wrote above in the commit
log.
^ permalink raw reply
* Re: [PATCH v1 0/2] virtio: PCI ERS permanent failure teardown for virtio-blk
From: Stefan Hajnoczi @ 2026-06-15 14:52 UTC (permalink / raw)
To: Xixin Liu
Cc: linux-block, virtualization, mst, jasowang, xuanzhuo, eperezma,
pbonzini, axboe, linux-kernel, Parav Pandit
In-Reply-To: <cover.virtio-blk-ers-v1.1780449274.git.liuxixin@kylinos.cn>
[-- Attachment #1: Type: text/plain, Size: 1472 bytes --]
On Mon, Jun 15, 2026 at 10:00:00AM +0800, Xixin Liu wrote:
> Hi,
>
> This series adds proper PCI AER error recovery handling for virtio-pci and
> completes virtio-blk teardown when ERS reports pci_channel_io_perm_failure.
CCing Parav because he previously looked at surprise removal:
https://lore.kernel.org/virtualization/20250822091706.21170-1-parav@nvidia.com/
>
> virtio-pci only registered reset_prepare/reset_done. The recovery core
> treats devices without error_detected as NO_AER_DRIVER and does not
> deliver perm_failure to the driver after a failed recovery. When bus
> reset fails (reproduced on QEMU with DLLLA not set within 100 ms after
> secondary bus reset), virtio-blk disks stay live even though virtqueues
> may already have been torn down during the frozen phase.
>
> Patch 1 registers error_detected (frozen quiesce + perm_failure notify).
> Patch 2 calls the virtio driver shutdown hook from virtio-pci on
> perm_failure, implements virtio-blk shutdown with blk_mark_disk_dead(),
> and fail-fast guards in virtio_queue_rq.
>
> Thanks,
> Xixin Liu
>
> ---
>
> Xixin Liu (2):
> virtio-pci: add error_detected for PCI AER recovery
> virtio-blk: mark disk dead on ERS permanent failure
>
> drivers/block/virtio_blk.c | 39 +++++++++++++++++++++++++++++++
> drivers/virtio/virtio_pci_common.c | 47 ++++++++++++++++++++++++++++++++++
> 2 files changed, 85 insertions(+)
>
> --
> 2.43.0
>
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^ permalink raw reply
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