Re: [PATCH] squash4: fix handling of fragments and sparse files

[Andrei Borzenkov]

24.02.2017 19:19, Andrei Borzenkov пишет:
>> How do you create those files reliably? Feel free to add any files to
>> grub-fs-tester. Feel free to commit without tests, we can add tests later.
>>
> 
> I would say, we need to generally create less "nice" test files
> 
> 1. Generate test files that are not exact multiple of filesystem block.
> This would cover squash tail packing and may uncover similar issues in
> other drivers as well.
> 
> 2. Generate sparse files by seeking beyond end of file. We already had
> similar problem with indirect ext* blocks that was not caught by tests.
> We should produce holes both for direct and indirect blocks (we may pick
> common offset or make it fs-specific if necessary).
> 
> 3. We need to produce really small files also to test inlining. Again we
> can pick common size or make it fs-specific.
> 
> Assuming we generate files as described, for squash4 just call it with
> -always-use-fragments to force tail packing. -nopad may be interesting
> as well to stress our driver even more.
> 
> 

Attached patch implements 1 + -always-use-fragments. It reliably causes
squash4 test to fail without my patch. I can change BLOCKCNT for squash4
only, but I think it makes sense to do globally.

sparse files need some tweaking in garbage-gen, will look into it.

squash4-tests.patch
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