[PATCH v4 0/3] block: show crypto capabilities in sysfs

[PATCH v4 0/3] block: show crypto capabilities in sysfs

[Eric Biggers]

This series adds sysfs files that expose the inline encryption
capabilities of request queues.

Patches 1 and 2 are some related cleanups for existing blk-sysfs code.
Patch 3 is the real change; see there for more details.

This series applies to v5.17-rc1.

Changed v3 => v4:
   - Reworded a comment in patch 2.
   - Updated dates in sysfs documentation.
   - Added more Reviewed-by tags.

Changed v2 => v3:
   - Moved the documentation into Documentation/ABI/stable/sysfs-block,
     and improved it a bit.
   - Write "/sys/block/" instead of "/sys/class/block/".
   - Added Reviewed-by tags.

Changed v1 => v2:
   - Use sysfs_emit() instead of sprintf().
   - Use __ATTR_RO().

Eric Biggers (3):
  block: simplify calling convention of elv_unregister_queue()
  block: don't delete queue kobject before its children
  blk-crypto: show crypto capabilities in sysfs

 Documentation/ABI/stable/sysfs-block |  49 ++++++++
 block/Makefile                       |   3 +-
 block/blk-crypto-internal.h          |  12 ++
 block/blk-crypto-sysfs.c             | 172 +++++++++++++++++++++++++++
 block/blk-crypto.c                   |   3 +
 block/blk-sysfs.c                    |  17 ++-
 block/elevator.c                     |   8 +-
 include/linux/blkdev.h               |   1 +
 8 files changed, 255 insertions(+), 10 deletions(-)
 create mode 100644 block/blk-crypto-sysfs.c


base-commit: e783362eb54cd99b2cac8b3a9aeac942e6f6ac07
-- 
2.34.1

[PATCH v4 1/3] block: simplify calling convention of elv_unregister_queue()

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

Make elv_unregister_queue() a no-op if q->elevator is NULL or is not
registered.

This simplifies the existing callers, as well as the future caller in
the error path of blk_register_queue().

Also don't bother checking whether q is NULL, since it never is.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 block/blk-sysfs.c | 3 +--
 block/elevator.c  | 8 ++++----
 2 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 9f32882ceb2f6..a02b42ad9a6e0 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -960,8 +960,7 @@ void blk_unregister_queue(struct gendisk *disk)
 	blk_trace_remove_sysfs(disk_to_dev(disk));
 
 	mutex_lock(&q->sysfs_lock);
-	if (q->elevator)
-		elv_unregister_queue(q);
+	elv_unregister_queue(q);
 	disk_unregister_independent_access_ranges(disk);
 	mutex_unlock(&q->sysfs_lock);
 	mutex_unlock(&q->sysfs_dir_lock);
diff --git a/block/elevator.c b/block/elevator.c
index ec98aed39c4f5..b062c5bc10b9a 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -516,9 +516,11 @@ int elv_register_queue(struct request_queue *q, bool uevent)
 
 void elv_unregister_queue(struct request_queue *q)
 {
+	struct elevator_queue *e = q->elevator;
+
 	lockdep_assert_held(&q->sysfs_lock);
 
-	if (q) {
+	if (e && e->registered) {
 		struct elevator_queue *e = q->elevator;
 
 		kobject_uevent(&e->kobj, KOBJ_REMOVE);
@@ -593,9 +595,7 @@ int elevator_switch_mq(struct request_queue *q,
 	lockdep_assert_held(&q->sysfs_lock);
 
 	if (q->elevator) {
-		if (q->elevator->registered)
-			elv_unregister_queue(q);
-
+		elv_unregister_queue(q);
 		ioc_clear_queue(q);
 		blk_mq_sched_free_rqs(q);
 		elevator_exit(q);
-- 
2.34.1

[PATCH v4 2/3] block: don't delete queue kobject before its children

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

kobjects aren't supposed to be deleted before their child kobjects are
deleted.  Apparently this is usually benign; however, a WARN will be
triggered if one of the child kobjects has a named attribute group:

    sysfs group 'modes' not found for kobject 'crypto'
    WARNING: CPU: 0 PID: 1 at fs/sysfs/group.c:278 sysfs_remove_group+0x72/0x80
    ...
    Call Trace:
      sysfs_remove_groups+0x29/0x40 fs/sysfs/group.c:312
      __kobject_del+0x20/0x80 lib/kobject.c:611
      kobject_cleanup+0xa4/0x140 lib/kobject.c:696
      kobject_release lib/kobject.c:736 [inline]
      kref_put include/linux/kref.h:65 [inline]
      kobject_put+0x53/0x70 lib/kobject.c:753
      blk_crypto_sysfs_unregister+0x10/0x20 block/blk-crypto-sysfs.c:159
      blk_unregister_queue+0xb0/0x110 block/blk-sysfs.c:962
      del_gendisk+0x117/0x250 block/genhd.c:610

Fix this by moving the kobject_del() and the corresponding
kobject_uevent() to the correct place.

Fixes: 2c2086afc2b8 ("block: Protect less code with sysfs_lock in blk_{un,}register_queue()")
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 block/blk-sysfs.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index a02b42ad9a6e0..66deaa9f3bc97 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -954,15 +954,17 @@ void blk_unregister_queue(struct gendisk *disk)
 	 */
 	if (queue_is_mq(q))
 		blk_mq_unregister_dev(disk_to_dev(disk), q);
-
-	kobject_uevent(&q->kobj, KOBJ_REMOVE);
-	kobject_del(&q->kobj);
 	blk_trace_remove_sysfs(disk_to_dev(disk));
 
 	mutex_lock(&q->sysfs_lock);
 	elv_unregister_queue(q);
 	disk_unregister_independent_access_ranges(disk);
 	mutex_unlock(&q->sysfs_lock);
+
+	/* Now that we've deleted all child objects, we can delete the queue. */
+	kobject_uevent(&q->kobj, KOBJ_REMOVE);
+	kobject_del(&q->kobj);
+
 	mutex_unlock(&q->sysfs_dir_lock);
 
 	kobject_put(&disk_to_dev(disk)->kobj);
-- 
2.34.1

[PATCH v4 3/3] blk-crypto: show crypto capabilities in sysfs

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

Add sysfs files that expose the inline encryption capabilities of
request queues:

	/sys/block/$disk/queue/crypto/max_dun_bits
	/sys/block/$disk/queue/crypto/modes/$mode
	/sys/block/$disk/queue/crypto/num_keyslots

Userspace can use these new files to decide what encryption settings to
use, or whether to use inline encryption at all.  This also brings the
crypto capabilities in line with the other queue properties, which are
already discoverable via the queue directory in sysfs.

Design notes:

  - Place the new files in a new subdirectory "crypto" to group them
    together and to avoid complicating the main "queue" directory.  This
    also makes it possible to replace "crypto" with a symlink later if
    we ever make the blk_crypto_profiles into real kobjects (see below).

  - It was necessary to define a new kobject that corresponds to the
    crypto subdirectory.  For now, this kobject just contains a pointer
    to the blk_crypto_profile.  Note that multiple queues (and hence
    multiple such kobjects) may refer to the same blk_crypto_profile.

    An alternative design would more closely match the current kernel
    data structures: the blk_crypto_profile could be a kobject itself,
    located directly under the host controller device's kobject, while
    /sys/block/$disk/queue/crypto would be a symlink to it.

    I decided not to do that for now because it would require a lot more
    changes, such as no longer embedding blk_crypto_profile in other
    structures, and also because I'm not sure we can rule out moving the
    crypto capabilities into 'struct queue_limits' in the future.  (Even
    if multiple queues share the same crypto engine, maybe the supported
    data unit sizes could differ due to other queue properties.)  It
    would also still be possible to switch to that design later without
    breaking userspace, by replacing the directory with a symlink.

  - Use "max_dun_bits" instead of "max_dun_bytes".  Currently, the
    kernel internally stores this value in bytes, but that's an
    implementation detail.  It probably makes more sense to talk about
    this value in bits, and choosing bits is more future-proof.

  - "modes" is a sub-subdirectory, since there may be multiple supported
    crypto modes, sysfs is supposed to have one value per file, and it
    makes sense to group all the mode files together.

  - Each mode had to be named.  The crypto API names like "xts(aes)" are
    not appropriate because they don't specify the key size.  Therefore,
    I assigned new names.  The exact names chosen are arbitrary, but
    they happen to match the names used in log messages in fs/crypto/.

  - The "num_keyslots" file is a bit different from the others in that
    it is only useful to know for performance reasons.  However, it's
    included as it can still be useful.  For example, a user might not
    want to use inline encryption if there aren't very many keyslots.

Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 Documentation/ABI/stable/sysfs-block |  49 ++++++++
 block/Makefile                       |   3 +-
 block/blk-crypto-internal.h          |  12 ++
 block/blk-crypto-sysfs.c             | 172 +++++++++++++++++++++++++++
 block/blk-crypto.c                   |   3 +
 block/blk-sysfs.c                    |   6 +
 include/linux/blkdev.h               |   1 +
 7 files changed, 245 insertions(+), 1 deletion(-)
 create mode 100644 block/blk-crypto-sysfs.c

diff --git a/Documentation/ABI/stable/sysfs-block b/Documentation/ABI/stable/sysfs-block
index 8dd3e84a8aade..e8797cd09aff9 100644
--- a/Documentation/ABI/stable/sysfs-block
+++ b/Documentation/ABI/stable/sysfs-block
@@ -155,6 +155,55 @@ Description:
 		last zone of the device which may be smaller.
 
 
+What:		/sys/block/<disk>/queue/crypto/
+Date:		February 2022
+Contact:	linux-block@vger.kernel.org
+Description:
+		The presence of this subdirectory of /sys/block/<disk>/queue/
+		indicates that the device supports inline encryption.  This
+		subdirectory contains files which describe the inline encryption
+		capabilities of the device.  For more information about inline
+		encryption, refer to Documentation/block/inline-encryption.rst.
+
+
+What:		/sys/block/<disk>/queue/crypto/max_dun_bits
+Date:		February 2022
+Contact:	linux-block@vger.kernel.org
+Description:
+		[RO] This file shows the maximum length, in bits, of data unit
+		numbers accepted by the device in inline encryption requests.
+
+
+What:		/sys/block/<disk>/queue/crypto/modes/<mode>
+Date:		February 2022
+Contact:	linux-block@vger.kernel.org
+Description:
+		[RO] For each crypto mode (i.e., encryption/decryption
+		algorithm) the device supports with inline encryption, a file
+		will exist at this location.  It will contain a hexadecimal
+		number that is a bitmask of the supported data unit sizes, in
+		bytes, for that crypto mode.
+
+		Currently, the crypto modes that may be supported are:
+
+		   * AES-256-XTS
+		   * AES-128-CBC-ESSIV
+		   * Adiantum
+
+		For example, if a device supports AES-256-XTS inline encryption
+		with data unit sizes of 512 and 4096 bytes, the file
+		/sys/block/<disk>/queue/crypto/modes/AES-256-XTS will exist and
+		will contain "0x1200".
+
+
+What:		/sys/block/<disk>/queue/crypto/num_keyslots
+Date:		February 2022
+Contact:	linux-block@vger.kernel.org
+Description:
+		[RO] This file shows the number of keyslots the device has for
+		use with inline encryption.
+
+
 What:		/sys/block/<disk>/queue/dax
 Date:		June 2016
 Contact:	linux-block@vger.kernel.org
diff --git a/block/Makefile b/block/Makefile
index f38eaa6129296..3950ecbc5c263 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -36,6 +36,7 @@ obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o
 obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o
 obj-$(CONFIG_BLK_SED_OPAL)	+= sed-opal.o
 obj-$(CONFIG_BLK_PM)		+= blk-pm.o
-obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o
+obj-$(CONFIG_BLK_INLINE_ENCRYPTION)	+= blk-crypto.o blk-crypto-profile.o \
+					   blk-crypto-sysfs.o
 obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK)	+= blk-crypto-fallback.o
 obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED)	+= holder.o
diff --git a/block/blk-crypto-internal.h b/block/blk-crypto-internal.h
index 2fb0d65a464ca..e6818ffaddbf8 100644
--- a/block/blk-crypto-internal.h
+++ b/block/blk-crypto-internal.h
@@ -11,6 +11,7 @@
 
 /* Represents a crypto mode supported by blk-crypto  */
 struct blk_crypto_mode {
+	const char *name; /* name of this mode, shown in sysfs */
 	const char *cipher_str; /* crypto API name (for fallback case) */
 	unsigned int keysize; /* key size in bytes */
 	unsigned int ivsize; /* iv size in bytes */
@@ -20,6 +21,10 @@ extern const struct blk_crypto_mode blk_crypto_modes[];
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 
+int blk_crypto_sysfs_register(struct request_queue *q);
+
+void blk_crypto_sysfs_unregister(struct request_queue *q);
+
 void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
 			     unsigned int inc);
 
@@ -62,6 +67,13 @@ static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
 
 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
 
+static inline int blk_crypto_sysfs_register(struct request_queue *q)
+{
+	return 0;
+}
+
+static inline void blk_crypto_sysfs_unregister(struct request_queue *q) { }
+
 static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
 					       struct bio *bio)
 {
diff --git a/block/blk-crypto-sysfs.c b/block/blk-crypto-sysfs.c
new file mode 100644
index 0000000000000..fd93bd2f33b75
--- /dev/null
+++ b/block/blk-crypto-sysfs.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 Google LLC
+ *
+ * sysfs support for blk-crypto.  This file contains the code which exports the
+ * crypto capabilities of devices via /sys/block/$disk/queue/crypto/.
+ */
+
+#include <linux/blk-crypto-profile.h>
+
+#include "blk-crypto-internal.h"
+
+struct blk_crypto_kobj {
+	struct kobject kobj;
+	struct blk_crypto_profile *profile;
+};
+
+struct blk_crypto_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct blk_crypto_profile *profile,
+			struct blk_crypto_attr *attr, char *page);
+};
+
+static struct blk_crypto_profile *kobj_to_crypto_profile(struct kobject *kobj)
+{
+	return container_of(kobj, struct blk_crypto_kobj, kobj)->profile;
+}
+
+static struct blk_crypto_attr *attr_to_crypto_attr(struct attribute *attr)
+{
+	return container_of(attr, struct blk_crypto_attr, attr);
+}
+
+static ssize_t max_dun_bits_show(struct blk_crypto_profile *profile,
+				 struct blk_crypto_attr *attr, char *page)
+{
+	return sysfs_emit(page, "%u\n", 8 * profile->max_dun_bytes_supported);
+}
+
+static ssize_t num_keyslots_show(struct blk_crypto_profile *profile,
+				 struct blk_crypto_attr *attr, char *page)
+{
+	return sysfs_emit(page, "%u\n", profile->num_slots);
+}
+
+#define BLK_CRYPTO_RO_ATTR(_name) \
+	static struct blk_crypto_attr _name##_attr = __ATTR_RO(_name)
+
+BLK_CRYPTO_RO_ATTR(max_dun_bits);
+BLK_CRYPTO_RO_ATTR(num_keyslots);
+
+static struct attribute *blk_crypto_attrs[] = {
+	&max_dun_bits_attr.attr,
+	&num_keyslots_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group blk_crypto_attr_group = {
+	.attrs = blk_crypto_attrs,
+};
+
+/*
+ * The encryption mode attributes.  To avoid hard-coding the list of encryption
+ * modes, these are initialized at boot time by blk_crypto_sysfs_init().
+ */
+static struct blk_crypto_attr __blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX];
+static struct attribute *blk_crypto_mode_attrs[BLK_ENCRYPTION_MODE_MAX + 1];
+
+static umode_t blk_crypto_mode_is_visible(struct kobject *kobj,
+					  struct attribute *attr, int n)
+{
+	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
+	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
+	int mode_num = a - __blk_crypto_mode_attrs;
+
+	if (profile->modes_supported[mode_num])
+		return 0444;
+	return 0;
+}
+
+static ssize_t blk_crypto_mode_show(struct blk_crypto_profile *profile,
+				    struct blk_crypto_attr *attr, char *page)
+{
+	int mode_num = attr - __blk_crypto_mode_attrs;
+
+	return sysfs_emit(page, "0x%x\n", profile->modes_supported[mode_num]);
+}
+
+static const struct attribute_group blk_crypto_modes_attr_group = {
+	.name = "modes",
+	.attrs = blk_crypto_mode_attrs,
+	.is_visible = blk_crypto_mode_is_visible,
+};
+
+static const struct attribute_group *blk_crypto_attr_groups[] = {
+	&blk_crypto_attr_group,
+	&blk_crypto_modes_attr_group,
+	NULL,
+};
+
+static ssize_t blk_crypto_attr_show(struct kobject *kobj,
+				    struct attribute *attr, char *page)
+{
+	struct blk_crypto_profile *profile = kobj_to_crypto_profile(kobj);
+	struct blk_crypto_attr *a = attr_to_crypto_attr(attr);
+
+	return a->show(profile, a, page);
+}
+
+static const struct sysfs_ops blk_crypto_attr_ops = {
+	.show = blk_crypto_attr_show,
+};
+
+static void blk_crypto_release(struct kobject *kobj)
+{
+	kfree(container_of(kobj, struct blk_crypto_kobj, kobj));
+}
+
+static struct kobj_type blk_crypto_ktype = {
+	.default_groups = blk_crypto_attr_groups,
+	.sysfs_ops	= &blk_crypto_attr_ops,
+	.release	= blk_crypto_release,
+};
+
+/*
+ * If the request_queue has a blk_crypto_profile, create the "crypto"
+ * subdirectory in sysfs (/sys/block/$disk/queue/crypto/).
+ */
+int blk_crypto_sysfs_register(struct request_queue *q)
+{
+	struct blk_crypto_kobj *obj;
+	int err;
+
+	if (!q->crypto_profile)
+		return 0;
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return -ENOMEM;
+	obj->profile = q->crypto_profile;
+
+	err = kobject_init_and_add(&obj->kobj, &blk_crypto_ktype, &q->kobj,
+				   "crypto");
+	if (err) {
+		kobject_put(&obj->kobj);
+		return err;
+	}
+	q->crypto_kobject = &obj->kobj;
+	return 0;
+}
+
+void blk_crypto_sysfs_unregister(struct request_queue *q)
+{
+	kobject_put(q->crypto_kobject);
+}
+
+static int __init blk_crypto_sysfs_init(void)
+{
+	int i;
+
+	BUILD_BUG_ON(BLK_ENCRYPTION_MODE_INVALID != 0);
+	for (i = 1; i < BLK_ENCRYPTION_MODE_MAX; i++) {
+		struct blk_crypto_attr *attr = &__blk_crypto_mode_attrs[i];
+
+		attr->attr.name = blk_crypto_modes[i].name;
+		attr->attr.mode = 0444;
+		attr->show = blk_crypto_mode_show;
+		blk_crypto_mode_attrs[i - 1] = &attr->attr;
+	}
+	return 0;
+}
+subsys_initcall(blk_crypto_sysfs_init);
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index ec9efeeeca918..f8a36c723a987 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -19,16 +19,19 @@
 
 const struct blk_crypto_mode blk_crypto_modes[] = {
 	[BLK_ENCRYPTION_MODE_AES_256_XTS] = {
+		.name = "AES-256-XTS",
 		.cipher_str = "xts(aes)",
 		.keysize = 64,
 		.ivsize = 16,
 	},
 	[BLK_ENCRYPTION_MODE_AES_128_CBC_ESSIV] = {
+		.name = "AES-128-CBC-ESSIV",
 		.cipher_str = "essiv(cbc(aes),sha256)",
 		.keysize = 16,
 		.ivsize = 16,
 	},
 	[BLK_ENCRYPTION_MODE_ADIANTUM] = {
+		.name = "Adiantum",
 		.cipher_str = "adiantum(xchacha12,aes)",
 		.keysize = 32,
 		.ivsize = 32,
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 66deaa9f3bc97..60092ce8e5f7c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -880,6 +880,10 @@ int blk_register_queue(struct gendisk *disk)
 			goto put_dev;
 	}
 
+	ret = blk_crypto_sysfs_register(q);
+	if (ret)
+		goto put_dev;
+
 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
 	wbt_enable_default(q);
 	blk_throtl_register_queue(q);
@@ -910,6 +914,7 @@ int blk_register_queue(struct gendisk *disk)
 	return ret;
 
 put_dev:
+	elv_unregister_queue(q);
 	disk_unregister_independent_access_ranges(disk);
 	mutex_unlock(&q->sysfs_lock);
 	mutex_unlock(&q->sysfs_dir_lock);
@@ -954,6 +959,7 @@ void blk_unregister_queue(struct gendisk *disk)
 	 */
 	if (queue_is_mq(q))
 		blk_mq_unregister_dev(disk_to_dev(disk), q);
+	blk_crypto_sysfs_unregister(q);
 	blk_trace_remove_sysfs(disk_to_dev(disk));
 
 	mutex_lock(&q->sysfs_lock);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9c95df26fc26b..c7e4ee7a24f8e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -262,6 +262,7 @@ struct request_queue {
 
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 	struct blk_crypto_profile *crypto_profile;
+	struct kobject *crypto_kobject;
 #endif
 
 	unsigned int		rq_timeout;
-- 
2.34.1

Re: [PATCH v4 1/3] block: simplify calling convention of elv_unregister_queue()

[Christoph Hellwig]

On Mon, Jan 24, 2022 at 01:59:36PM -0800, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Make elv_unregister_queue() a no-op if q->elevator is NULL or is not
> registered.
> 
> This simplifies the existing callers, as well as the future caller in
> the error path of blk_register_queue().
> 
> Also don't bother checking whether q is NULL, since it never is.
> 
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Reviewed-by: Bart Van Assche <bvanassche@acm.org>
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH v4 2/3] block: don't delete queue kobject before its children

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH v4 0/3] block: show crypto capabilities in sysfs

[Eric Biggers]

On Mon, Jan 24, 2022 at 01:59:35PM -0800, Eric Biggers wrote:
> This series adds sysfs files that expose the inline encryption
> capabilities of request queues.
> 
> Patches 1 and 2 are some related cleanups for existing blk-sysfs code.
> Patch 3 is the real change; see there for more details.
> 
> This series applies to v5.17-rc1.
> 
> Changed v3 => v4:
>    - Reworded a comment in patch 2.
>    - Updated dates in sysfs documentation.
>    - Added more Reviewed-by tags.
> 
> Changed v2 => v3:
>    - Moved the documentation into Documentation/ABI/stable/sysfs-block,
>      and improved it a bit.
>    - Write "/sys/block/" instead of "/sys/class/block/".
>    - Added Reviewed-by tags.
> 
> Changed v1 => v2:
>    - Use sysfs_emit() instead of sprintf().
>    - Use __ATTR_RO().
> 
> Eric Biggers (3):
>   block: simplify calling convention of elv_unregister_queue()
>   block: don't delete queue kobject before its children
>   blk-crypto: show crypto capabilities in sysfs
> 

Any more feedback on this?

- Eric

Re: [PATCH v4 0/3] block: show crypto capabilities in sysfs

[Eric Biggers]

On Sun, Feb 20, 2022 at 06:23:29PM -0800, Eric Biggers wrote:
> On Mon, Jan 24, 2022 at 01:59:35PM -0800, Eric Biggers wrote:
> > This series adds sysfs files that expose the inline encryption
> > capabilities of request queues.
> > 
> > Patches 1 and 2 are some related cleanups for existing blk-sysfs code.
> > Patch 3 is the real change; see there for more details.
> > 
> > This series applies to v5.17-rc1.
> > 
> > Changed v3 => v4:
> >    - Reworded a comment in patch 2.
> >    - Updated dates in sysfs documentation.
> >    - Added more Reviewed-by tags.
> > 
> > Changed v2 => v3:
> >    - Moved the documentation into Documentation/ABI/stable/sysfs-block,
> >      and improved it a bit.
> >    - Write "/sys/block/" instead of "/sys/class/block/".
> >    - Added Reviewed-by tags.
> > 
> > Changed v1 => v2:
> >    - Use sysfs_emit() instead of sprintf().
> >    - Use __ATTR_RO().
> > 
> > Eric Biggers (3):
> >   block: simplify calling convention of elv_unregister_queue()
> >   block: don't delete queue kobject before its children
> >   blk-crypto: show crypto capabilities in sysfs
> > 
> 
> Any more feedback on this?
> 

Jens, can you apply this for 5.18?  Is there anything else you're waiting for?

- Eric

Re: [PATCH v4 0/3] block: show crypto capabilities in sysfs

[Jens Axboe]

On Mon, 24 Jan 2022 13:59:35 -0800, Eric Biggers wrote:
> This series adds sysfs files that expose the inline encryption
> capabilities of request queues.
> 
> Patches 1 and 2 are some related cleanups for existing blk-sysfs code.
> Patch 3 is the real change; see there for more details.
> 
> This series applies to v5.17-rc1.
> 
> [...]

Applied, thanks!

[1/3] block: simplify calling convention of elv_unregister_queue()
      commit: f5ec592dd3bcf7c91f7c262a7f5011e001d269cd
[2/3] block: don't delete queue kobject before its children
      commit: 0f69288253e9fc7c495047720e523b9f1aba5712
[3/3] blk-crypto: show crypto capabilities in sysfs
      commit: 20f01f163203666010ee1560852590a0c0572726

Best regards,
-- 
Jens Axboe