Merge tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux

Pull block updates from Jens Axboe:

 - NVMe updates via Christoph:
      - Small improvements to the logging functionality (Amit Engel)
      - Authentication cleanups (Hannes Reinecke)
      - Cleanup and optimize the DMA mapping cod in the PCIe driver
        (Keith Busch)
      - Work around the command effects for Format NVM (Keith Busch)
      - Misc cleanups (Keith Busch, Christoph Hellwig)
      - Fix and cleanup freeing single sgl (Keith Busch)

 - MD updates via Song:
      - Fix a rare crash during the takeover process
      - Don't update recovery_cp when curr_resync is ACTIVE
      - Free writes_pending in md_stop
      - Change active_io to percpu

 - Updates to drbd, inching us closer to unifying the out-of-tree driver
   with the in-tree one (Andreas, Christoph, Lars, Robert)

 - BFQ update adding support for multi-actuator drives (Paolo, Federico,
   Davide)

 - Make brd compliant with REQ_NOWAIT (me)

 - Fix for IOPOLL and queue entering, fixing stalled IO waiting on
   timeouts (me)

 - Fix for REQ_NOWAIT with multiple bios (me)

 - Fix memory leak in blktrace cleanup (Greg)

 - Clean up sbitmap and fix a potential hang (Kemeng)

 - Clean up some bits in BFQ, and fix a bug in the request injection
   (Kemeng)

 - Clean up the request allocation and issue code, and fix some bugs
   related to that (Kemeng)

 - ublk updates and fixes:
      - Add support for unprivileged ublk (Ming)
      - Improve device deletion handling (Ming)
      - Misc (Liu, Ziyang)

 - s390 dasd fixes (Alexander, Qiheng)

 - Improve utility of request caching and fixes (Anuj, Xiao)

 - zoned cleanups (Pankaj)

 - More constification for kobjs (Thomas)

 - blk-iocost cleanups (Yu)

 - Remove bio splitting from drivers that don't need it (Christoph)

 - Switch blk-cgroups to use struct gendisk. Some of this is now
   incomplete as select late reverts were done. (Christoph)

 - Add bvec initialization helpers, and convert callers to use that
   rather than open-coding it (Christoph)

 - Misc fixes and cleanups (Jinke, Keith, Arnd, Bart, Li, Martin,
   Matthew, Ulf, Zhong)

* tag 'for-6.3/block-2023-02-16' of git://git.kernel.dk/linux: (169 commits)
  brd: use radix_tree_maybe_preload instead of radix_tree_preload
  block: use proper return value from bio_failfast()
  block: bio-integrity: Copy flags when bio_integrity_payload is cloned
  block: Fix io statistics for cgroup in throttle path
  brd: mark as nowait compatible
  brd: check for REQ_NOWAIT and set correct page allocation mask
  brd: return 0/-error from brd_insert_page()
  block: sync mixed merged request's failfast with 1st bio's
  Revert "blk-cgroup: pin the gendisk in struct blkcg_gq"
  Revert "blk-cgroup: pass a gendisk to blkg_lookup"
  Revert "blk-cgroup: delay blk-cgroup initialization until add_disk"
  Revert "blk-cgroup: delay calling blkcg_exit_disk until disk_release"
  Revert "blk-cgroup: move the cgroup information to struct gendisk"
  nvme-pci: remove iod use_sgls
  nvme-pci: fix freeing single sgl
  block: ublk: check IO buffer based on flag need_get_data
  s390/dasd: Fix potential memleak in dasd_eckd_init()
  s390/dasd: sort out physical vs virtual pointers usage
  block: Remove the ALLOC_CACHE_SLACK constant
  block: make kobj_type structures constant
  ...

1 files changed, 47 insertions, 2 deletions

diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 8f88e3a29998..f6238ccc7800 100644
--- a/include/uapi/linux/ublk_cmd.h
+++ b/include/uapi/linux/ublk_cmd.h
@@ -19,6 +19,8 @@
 #define	UBLK_CMD_GET_PARAMS	0x09
 #define	UBLK_CMD_START_USER_RECOVERY	0x10
 #define	UBLK_CMD_END_USER_RECOVERY	0x11
+#define	UBLK_CMD_GET_DEV_INFO2		0x12
+
 /*
  * IO commands, issued by ublk server, and handled by ublk driver.
  *
@@ -79,6 +81,27 @@
 
 #define UBLK_F_USER_RECOVERY_REISSUE	(1UL << 4)
 
+/*
+ * Unprivileged user can create /dev/ublkcN and /dev/ublkbN.
+ *
+ * /dev/ublk-control needs to be available for unprivileged user, and it
+ * can be done via udev rule to make all control commands available to
+ * unprivileged user. Except for the command of UBLK_CMD_ADD_DEV, all
+ * other commands are only allowed for the owner of the specified device.
+ *
+ * When userspace sends UBLK_CMD_ADD_DEV, the device pair's owner_uid and
+ * owner_gid are stored to ublksrv_ctrl_dev_info by kernel, so far only
+ * the current user's uid/gid is stored, that said owner of the created
+ * device is always the current user.
+ *
+ * We still need udev rule to apply OWNER/GROUP with the stored owner_uid
+ * and owner_gid.
+ *
+ * Then ublk server can be run as unprivileged user, and /dev/ublkbN can
+ * be accessed and managed by its owner represented by owner_uid/owner_gid.
+ */
+#define UBLK_F_UNPRIVILEGED_DEV	(1UL << 5)
+
 /* device state */
 #define UBLK_S_DEV_DEAD	0
 #define UBLK_S_DEV_LIVE	1
@@ -98,7 +121,15 @@ struct ublksrv_ctrl_cmd {
 	__u64	addr;
 
 	/* inline data */
-	__u64	data[2];
+	__u64	data[1];
+
+	/*
+	 * Used for UBLK_F_UNPRIVILEGED_DEV and UBLK_CMD_GET_DEV_INFO2
+	 * only, include null char
+	 */
+	__u16	dev_path_len;
+	__u16	pad;
+	__u32	reserved;
 };
 
 struct ublksrv_ctrl_dev_info {
@@ -118,7 +149,8 @@ struct ublksrv_ctrl_dev_info {
 	/* For ublksrv internal use, invisible to ublk driver */
 	__u64	ublksrv_flags;
 
-	__u64	reserved0;
+	__u32	owner_uid;	/* store by kernel */
+	__u32	owner_gid;	/* store by kernel */
 	__u64	reserved1;
 	__u64   reserved2;
 };
@@ -214,6 +246,17 @@ struct ublk_param_discard {
 	__u16	reserved0;
 };
 
+/*
+ * read-only, can't set via UBLK_CMD_SET_PARAMS, disk_devt is available
+ * after device is started
+ */
+struct ublk_param_devt {
+	__u32   char_major;
+	__u32   char_minor;
+	__u32   disk_major;
+	__u32   disk_minor;
+};
+
 struct ublk_params {
 	/*
 	 * Total length of parameters, userspace has to set 'len' for both
@@ -224,10 +267,12 @@ struct ublk_params {
 	__u32	len;
 #define UBLK_PARAM_TYPE_BASIC           (1 << 0)
 #define UBLK_PARAM_TYPE_DISCARD         (1 << 1)
+#define UBLK_PARAM_TYPE_DEVT            (1 << 2)
 	__u32	types;			/* types of parameter included */
 
 	struct ublk_param_basic		basic;
 	struct ublk_param_discard	discard;
+	struct ublk_param_devt		devt;
 };
 
 #endif