Missing 2 blocks on my UBI partition

[Patrick Doyle <wpdster@xxxxxxxxx>]

I'm curious to learn where 2 blocks went missing from my UBI NAND
device... can anybody help me out:

# ubinfo -a
UBI version:                    1
Count of UBI devices:           1
UBI control device major/minor: 10:57
Present UBI devices:            ubi0

ubi0
Volumes count:                           8
Logical eraseblock size:                 126976 bytes, 124.0 KiB
Total amount of logical eraseblocks:     1024 (130023424 bytes, 124.0 MiB)
Amount of available logical eraseblocks: 99 (12570624 bytes, 11.9 MiB)
Maximum count of volumes                 128
Count of bad physical eraseblocks:       0
Count of reserved physical eraseblocks:  20
Current maximum erase counter value:     33
Minimum input/output unit size:          2048 bytes
Character device major/minor:            252:0
Present volumes:                         0, 1, 2, 3, 4, 5, 6, 7

Volume ID:   0 (on ubi0)
Type:        static
Alignment:   1
Size:        127 LEBs (16125952 bytes, 15.3 MiB)
Data bytes:  16031744 bytes (15.2 MiB)
State:       OK
Name:        rootfs
Character device major/minor: 252:1
-----------------------------------
Volume ID:   1 (on ubi0)
Type:        dynamic
Alignment:   1
Size:        529 LEBs (67170304 bytes, 64.0 MiB)
State:       OK
Name:        persistent
Character device major/minor: 252:2
-----------------------------------
Volume ID:   2 (on ubi0)
Type:        static
Alignment:   1
Size:        30 LEBs (3809280 bytes, 3.6 MiB)
Data bytes:  3746638 bytes (3.5 MiB)
State:       OK
Name:        kernel
Character device major/minor: 252:3
-----------------------------------
Volume ID:   3 (on ubi0)
Type:        static
Alignment:   1
Size:        143 LEBs (18157568 bytes, 17.3 MiB)
Data bytes:  18145280 bytes (17.3 MiB)
State:       OK
Name:        old_rootfs
Character device major/minor: 252:4
-----------------------------------
Volume ID:   4 (on ubi0)
Type:        static
Alignment:   1
Size:        30 LEBs (3809280 bytes, 3.6 MiB)
Data bytes:  3745994 bytes (3.5 MiB)
State:       OK
Name:        old_kernel
Character device major/minor: 252:5
-----------------------------------
Volume ID:   5 (on ubi0)
Type:        static
Alignment:   1
Size:        38 LEBs (4825088 bytes, 4.6 MiB)
Data bytes:  4763648 bytes (4.5 MiB)
State:       OK
Name:        language
Character device major/minor: 252:6
-----------------------------------
Volume ID:   6 (on ubi0)
Type:        static
Alignment:   1
Size:        1 LEBs (126976 bytes, 124.0 KiB)
Data bytes:  65536 bytes (64.0 KiB)
State:       OK
Name:        crypto
Character device major/minor: 252:7
-----------------------------------
Volume ID:   7 (on ubi0)
Type:        static
Alignment:   1
Size:        1 LEBs (126976 bytes, 124.0 KiB)
Data bytes:  65536 bytes (64.0 KiB)
State:       OK
Name:        prev_crypto
Character device major/minor: 252:8

This shows that I have 8 UBI Volumes with sized as:
Size:        127 LEBs (16125952 bytes, 15.3 MiB)
Size:        529 LEBs (67170304 bytes, 64.0 MiB)
Size:        30 LEBs (3809280 bytes, 3.6 MiB)
Size:        143 LEBs (18157568 bytes, 17.3 MiB)
Size:        30 LEBs (3809280 bytes, 3.6 MiB)
Size:        38 LEBs (4825088 bytes, 4.6 MiB)
Size:        1 LEBs (126976 bytes, 124.0 KiB)
Size:        1 LEBs (126976 bytes, 124.0 KiB)
Total: 899 LEBs
There are 99 blocks free, 20 blocks reserved, and (according to the
documentation, 4 blocks of UBI management overhead

899+99+20+4=1022

But my NAND flash has 1024 blocks.  According to ubinfo, none of them
are marked as bad.

Where did the other 2 blocks go?

What am I missing?

--wpd

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