[LEDE-DEV] [PATCH] include: image.mk: ext4: double the default inode counter

[Felix Fietkau]

On 2016-11-22 18:04, Felix Fietkau wrote:
> On 2016-11-22 17:57, David Lang wrote:
>> On Tue, 22 Nov 2016, Felix Fietkau wrote:
>> 
>>> On 2016-11-22 17:48, David Lang wrote:
>>>> On Tue, 22 Nov 2016, Felix Fietkau wrote:
>>>>
>>>>> On 2016-11-22 17:43, David Lang wrote:
>>>>>> On Tue, 22 Nov 2016, Felix Fietkau wrote:
>>>>>>
>>>>>>>> On a 16M filesystem, we probably want to use a 1K block size and have an inode
>>>>>>>> for every couple of blocks.
>>>>>>> I'd say on a 16M filesystem we probably want to use squashfs+ext4
>>>>>>> instead of plain ext4 and avoid the inode issue altogether.
>>>>>>
>>>>>> I'm not sure I understand how this would work?
>>>>> Pad a plain squashfs image to the intended target size, include mke2fs
>>>>> and mkf2fs (for bigger sizes) in the image.
>>>>> fstools will take care of the rest at boot time.
>>>>
>>>> you still have to set the parameters for mkfs to use.
>>> It will be created as an empty overlay filesystem, so there's lots of
>>> free inodes available.
>> 
>> but by default, it wouldn't have lots of free inodes, the default is one inode 
>> per 16K of filesystem, which is how we get to 1024 inodes on a 16M filesystem.
>> 
>> We need to be able to say that this is a tiny filesystem, and should really use 
>> a smaller blocksize and more inodes.
> FWIW, I just pushed a commit to my staging tree that adds squashfs
> support for the uml target.
> I tested it and it's usable with 16M rootfs.
Here's some more information: it creates the overlay filesystem with a
block size of 1K, and it has 3493 free inodes after booting up.

- Felix