Re: [PATCH v3 3/6] badblocks: improvement badblocks_set() for multiple ranges handling

[Wols Lists <antlists@youngman.org.uk>]

On 09/12/2021 07:28, Geliang Tang wrote:
> On Thu, Dec 02, 2021 at 08:52:41PM +0800, Coly Li wrote:
>> Recently I received a bug report that current badblocks code does not

> 
>> + *        +--------+----+
>> + *        |    S   | E  |
>> + *        +--------+----+
>> + * 2.2) The setting range size == already set range size
>> + * 2.2.1) If S and E are both acked or unacked range, the setting range S can
>> + *    be merged into existing bad range E. The result is,
>> + *        +-------------+
>> + *        |      S      |
>> + *        +-------------+
>> + * 2.2.2) If S is uncked setting and E is acked, the setting will be denied, and
> 
> uncked -> unacked
> 
>> + *    the result is,
>> + *        +-------------+
>> + *        |      E      |
>> + *        +-------------+
>> + * 2.2.3) If S is acked setting and E is unacked, range S can overwirte all of

overwirte -> overwrite

>> +      bad blocks range E. The result is,
>> + *        +-------------+
>> + *        |      S      |
>> + *        +-------------+
>> + * 2.3) The setting range size > already set range size
>> + *        +-------------------+
>> + *        |          S        |
>> + *        +-------------------+
>> + *        +-------------+
>> + *        |      E      |
>> + *        +-------------+
>> + *    For such situation, the setting range S can be treated as two parts, the
>> + *    first part (S1) is as same size as the already set range E, the second
>> + *    part (S2) is the rest of setting range.
>> + *        +-------------+-----+        +-------------+       +-----+
>> + *        |    S1       | S2  |        |     S1      |       | S2  |
>> + *        +-------------+-----+  ===>  +-------------+       +-----+
>> + *        +-------------+              +-------------+
>> + *        |      E      |              |      E      |
>> + *        +-------------+              +-------------+
>> + *    Now we only focus on how to handle the setting range S1 and already set
>> + *    range E, which are already explained in 1.2), for the rest S2 it will be
> 
Cheers,
Wol