Merge tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux

Pull more block updates from Jens Axboe:

 - MD pull request via Song:
      - Improve raid5 sequential IO performance on spinning disks, which
        fixes a regression since v6.0 (Jan Kara)
      - Fix bitmap offset types, which fixes an issue introduced in this
        merge window (Jonathan Derrick)

 - Cleanup of hweight type used for cgroup writeback (Maxim)

 - Fix a regression with the "has_submit_bio" changes across partitions
   (Ming)

 - Cleanup of QUEUE_FLAG_ADD_RANDOM clearing.

   We used to set this flag on queues non blk-mq queues, and hence some
   drivers clear it unconditionally. Since all of these have since been
   converted to true blk-mq drivers, drop the useless clear as the bit
   is not set (Chaitanya)

 - Fix the flags being set in a bio for a flush for drbd (Christoph)

 - Cleanup and deduplication of the code handling setting block device
   capacity (Damien)

 - Fix for ublk handling IO timeouts (Ming)

 - Fix for a regression in blk-cgroup teardown (Tao)

 - NBD documentation and code fixes (Eric)

 - Convert blk-integrity to using device_attributes rather than a second
   kobject to manage lifetimes (Thomas)

* tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux:
  ublk: add timeout handler
  drbd: correctly submit flush bio on barrier
  mailmap: add mailmap entries for Jens Axboe
  block: Skip destroyed blkg when restart in blkg_destroy_all()
  writeback: fix call of incorrect macro
  md: Fix bitmap offset type in sb writer
  md/raid5: Improve performance for sequential IO
  docs nbd: userspace NBD now favors github over sourceforge
  block nbd: use req.cookie instead of req.handle
  uapi nbd: add cookie alias to handle
  uapi nbd: improve doc links to userspace spec
  blk-integrity: register sysfs attributes on struct device
  blk-integrity: convert to struct device_attribute
  blk-integrity: use sysfs_emit
  block/drivers: remove dead clear of random flag
  block: sync part's ->bd_has_submit_bio with disk's
  block: Cleanup set_capacity()/bdev_set_nr_sectors()

1 files changed, 20 insertions, 5 deletions

diff --git a/include/uapi/linux/nbd.h b/include/uapi/linux/nbd.h
index 20d6cc91435d..80ce0ef43afd 100644
--- a/include/uapi/linux/nbd.h
+++ b/include/uapi/linux/nbd.h
@@ -11,6 +11,8 @@
  *            Cleanup PARANOIA usage & code.
  * 2004/02/19 Paul Clements
  *            Removed PARANOIA, plus various cleanup and comments
+ * 2023 Copyright Red Hat
+ *            Link to userspace extensions, favor cookie over handle.
  */
 
 #ifndef _UAPILINUX_NBD_H
@@ -30,12 +32,18 @@
 #define NBD_SET_TIMEOUT _IO( 0xab, 9 )
 #define NBD_SET_FLAGS   _IO( 0xab, 10)
 
+/*
+ * See also https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md
+ * for additional userspace extensions not yet utilized in the kernel module.
+ */
+
 enum {
 	NBD_CMD_READ = 0,
 	NBD_CMD_WRITE = 1,
 	NBD_CMD_DISC = 2,
 	NBD_CMD_FLUSH = 3,
 	NBD_CMD_TRIM = 4
+	/* userspace defines additional extension commands */
 };
 
 /* values for flags field, these are server interaction specific. */
@@ -64,15 +72,19 @@ enum {
 #define NBD_REQUEST_MAGIC 0x25609513
 #define NBD_REPLY_MAGIC 0x67446698
 /* Do *not* use magics: 0x12560953 0x96744668. */
+/* magic 0x668e33ef for structured reply not supported by kernel yet */
 
 /*
  * This is the packet used for communication between client and
  * server. All data are in network byte order.
  */
 struct nbd_request {
-	__be32 magic;
-	__be32 type;	/* == READ || == WRITE 	*/
-	char handle[8];
+	__be32 magic;	/* NBD_REQUEST_MAGIC	*/
+	__be32 type;	/* See NBD_CMD_*	*/
+	union {
+		__be64 cookie;	/* Opaque identifier for request	*/
+		char handle[8];	/* older spelling of cookie		*/
+	};
 	__be64 from;
 	__be32 len;
 } __attribute__((packed));
@@ -82,8 +94,11 @@ struct nbd_request {
  * it has completed an I/O request (or an error occurs).
  */
 struct nbd_reply {
-	__be32 magic;
+	__be32 magic;		/* NBD_REPLY_MAGIC	*/
 	__be32 error;		/* 0 = ok, else error	*/
-	char handle[8];		/* handle you got from request	*/
+	union {
+		__be64 cookie;	/* Opaque identifier from request	*/
+		char handle[8];	/* older spelling of cookie		*/
+	};
 };
 #endif /* _UAPILINUX_NBD_H */