Re: [RESEND PATCH] block: cmdline-parser: add support for hidden disk space

[Shawn Lin <shawn.lin@rock-chips.com>]

On 2015/9/28 18:48, Caizhiyong wrote:
> Dear Shawn Lin:
>
>       The cmdline-parser is support skip some reserve disk space, or hidden some disk space.
>
>       See Documentation/block/cmdline-partition.txt

Wow, that's just what I need. Thanks.

>
> blkdevparts=<blkdev-def>[;<blkdev-def>]
>    <blkdev-def> := <blkdev-id>:<partdef>[,<partdef>]
>      <partdef> := <size>[@<offset>](part-name)
>
>      The "offset" is next partition start address, If your bootargs is 'blkdevparts=mmcblk0:1G(data0),1G@2G(data1),-;', you will reserve 1G between mmcblk0p1 and mmcblk0p2;
>
> Looking forward to your feedback.
> Best regards.
> Cai Zhiyong.
> http://www.huawei.com
>
>> -----Original Message-----
>> From: Shawn Lin [mailto:shawn.lin@rock-chips.com]
>> Sent: Monday, September 28, 2015 5:51 PM
>> To: Jens Axboe
>> Cc: Caizhiyong; linux-kernel@vger.kernel.org; Shawn Lin
>> Subject: [RESEND PATCH] block: cmdline-parser: add support for hidden disk
>> space
>>
>> cmdline-partition now only support continuous disk space taken from
>> cmdline. When we need to reserve a disk space, for instance, 100m between
>> mmcblk0p1 and mmcblk0p2 for special use and wouldn't let kernel space
>> realize this "disk hole", we add this patch to ship adding this kind of
>> "disk hole" into the partition table. For any such cases, simply append
>> "hidden" to the end of subpart which is need to be reserved.
>>
>> Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
>>
>> ---
>>
>>   block/cmdline-parser.c         | 12 +++++++++++-
>>   include/linux/cmdline-parser.h |  1 +
>>   2 files changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/block/cmdline-parser.c b/block/cmdline-parser.c
>> index 9dbc67e..fcca57d 100644
>> --- a/block/cmdline-parser.c
>> +++ b/block/cmdline-parser.c
>> @@ -68,6 +68,11 @@ static int parse_subpart(struct cmdline_subpart
>> **subpart, char *partdef)
>>   		partdef += 2;
>>   	}
>>
>> +	if (!strncmp(partdef, "hidden", 6)) {
>> +		new_subpart->flags |= PF_HIDDEN;
>> +		partdef += 6;
>> +	}
>> +
>>   	*subpart = new_subpart;
>>   	return 0;
>>   fail:
>> @@ -128,7 +133,9 @@ static int parse_parts(struct cmdline_parts **parts,
>> const char *bdevdef)
>>   		if (ret)
>>   			goto fail;
>>
>> -		newparts->nr_subparts++;
>> +		if (!((*next_subpart)->flags & PF_HIDDEN))
>> +			newparts->nr_subparts++;
>> +
>>   		next_subpart = &(*next_subpart)->next_subpart;
>>   	}
>>
>> @@ -245,6 +252,9 @@ int cmdline_parts_set(struct cmdline_parts *parts,
>> sector_t disk_size,
>>
>>   		from += subpart->size;
>>
>> +		if (subpart->flags & PF_HIDDEN)
>> +			continue;
>> +
>>   		if (add_part(slot, subpart, param))
>>   			break;
>>   	}
>> diff --git a/include/linux/cmdline-parser.h b/include/linux/cmdline-parser.h
>> index 2e6dce6..7c1cb3c 100644
>> --- a/include/linux/cmdline-parser.h
>> +++ b/include/linux/cmdline-parser.h
>> @@ -14,6 +14,7 @@
>>   /* partition flags */
>>   #define PF_RDONLY                   0x01 /* Device is read only */
>>   #define PF_POWERUP_LOCK             0x02 /* Always locked after reset
>> */
>> +#define PF_HIDDEN                   0x04 /* Hidden from partition
>> table */
>>
>>   struct cmdline_subpart {
>>   	char name[BDEVNAME_SIZE]; /* partition name, such as 'rootfs' */
>> --
>> 2.3.7
>>
>
>
>
>


-- 
Best Regards
Shawn Lin