[RFC] disk/part: partition number parsed as hex in blk_get_device_part_str

Hello,

While testing GPT partitions on USB media, I noticed that partition identifiers passed on the command line appear to be parsed as hexadecimal values.

Example:

=> part list usb 0

Partition Map for USB device 0  --   Partition Type: EFI

Part    Start LBA       End LBA         Name
        Attributes
        Type GUID
        Partition GUID
  1     0x00000800      0x008007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   5d33e1b1-c3ae-4e58-8677-13a295ce7b41
  2     0x00800800      0x010007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   277f159b-1239-4be1-bc1e-54c718331584
  3     0x01000800      0x018007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   470b684e-6d99-4a26-866f-14663b13dcbf
  4     0x01800800      0x020007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   1f598bf7-5d31-47bf-9a1d-75c2c6b74dd4
  5     0x02000800      0x028007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   30491f52-e2d7-4f15-8925-92c00ca6e8fb
  6     0x02800800      0x030007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   aef06b97-9320-494b-bff9-3f2cb472ba7f
  7     0x03000800      0x038007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   74143690-f5ab-4437-949e-b098199435c3
  8     0x03800800      0x040007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   fca32ea9-8165-404a-8eac-b22b80a15c8a
  9     0x04000800      0x048007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   fd4d818b-205e-43ef-9de5-7be6bf8550c8
10     0x04800800      0x050007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   a4b21c4c-f0cf-4fb7-b70a-0f191b9fd874
11     0x05000800      0x058007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   243ae3ce-4fd5-4230-ba83-137d8655ea8c
12     0x05800800      0x060007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   671bdeba-dd6a-43e0-a99c-e880ebab991b
13     0x06000800      0x068007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   b5fd6923-e40b-4018-9808-541c91ec81f5
14     0x06800800      0x070007ff      ""
        attrs:  0x0000000000000000
        type:   0fc63daf-8483-4772-8e79-3d69d8477de4
        guid:   29634671-56d8-45f7-8a22-f2b7c33520a5


Partition 9 can be accessed successfully:

=> part uuid usb 0:9
fd4d818b-205e-43ef-9de5-7be6bf8550c8

However:

=> part uuid usb 0:10
** Invalid partition 16 **

=> part uuid usb 0:11
** Invalid partition 17 **

Looking at blk_get_device_part_str() the partition number is parsed with:

    part = (int)hextoul(part_str, &ep);

which converts:

    10 -> 16
    11 -> 17

Since "part list" displays partition identifiers in decimal, users reasonably expect "0:10" to refer to partition 10 rather than partition 16.

Is this behavior intentional for backward compatibility, or would decimal parsing be preferred?

Thanks,
Albin Raj
Best Regards,
Albin Raj R J
Advanced Software Engineer
APTIV, TCI, Bangalore.



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