Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Block layer patches

- qemu-storage-daemon: Add vhost-user-blk help
- block-backend: Fix use-after-free for BDS pointers after aio_poll()
- qemu-img: Fix sparseness of output image with unaligned ranges
- vvfat: Fix crashes in read-write mode
- Fix device deletion events with -device JSON syntax
- Code cleanups

# gpg: Signature made Fri 14 Jan 2022 13:50:16 GMT
# gpg:                using RSA key DC3DEB159A9AF95D3D7456FE7F09B272C88F2FD6
# gpg:                issuer "kwolf@redhat.com"
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>" [full]
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  iotests/testrunner.py: refactor test_field_width
  block: drop BLK_PERM_GRAPH_MOD
  qemu-img: make is_allocated_sectors() more efficient
  iotests: Test qemu-img convert of zeroed data cluster
  vvfat: Fix vvfat_write() for writes before the root directory
  vvfat: Fix size of temporary qcow file
  iotests/308: Fix for CAP_DAC_OVERRIDE
  iotests/stream-error-on-reset: New test
  block-backend: prevent dangling BDS pointers across aio_poll()
  qapi/block: Restrict vhost-user-blk to CONFIG_VHOST_USER_BLK_SERVER
  qemu-storage-daemon: Add vhost-user-blk help
  docs: Correct 'vhost-user-blk' spelling
  softmmu: fix device deletion events with -device JSON syntax
  include/sysemu/blockdev.h: remove drive_get_max_devs
  include/sysemu/blockdev.h: remove drive_mark_claimed_by_board and inline drive_def
  block_int: make bdrv_backing_overridden static

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

include/block/block.h

@@ -269,12 +269,13 @@ enum {
     BLK_PERM_RESIZE             = 0x08,
 
     /**
-     * This permission is required to change the node that this BdrvChild
-     * points to.
+     * There was a now-removed bit BLK_PERM_GRAPH_MOD, with value of 0x10. QEMU
+     * 6.1 and earlier may still lock the corresponding byte in block/file-posix
+     * locking.  So, implementing some new permission should be very careful to
+     * not interfere with this old unused thing.
      */
-    BLK_PERM_GRAPH_MOD          = 0x10,
 
-    BLK_PERM_ALL                = 0x1f,
+    BLK_PERM_ALL                = 0x0f,
 
     DEFAULT_PERM_PASSTHROUGH    = BLK_PERM_CONSISTENT_READ
                                  | BLK_PERM_WRITE

include/block/block_int.h

@@ -1122,9 +1122,6 @@ BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size,
 void bdrv_parse_filename_strip_prefix(const char *filename, const char *prefix,
                                       QDict *options);
 
-bool bdrv_backing_overridden(BlockDriverState *bs);
-
-
 /**
  * bdrv_add_aio_context_notifier:
  *