[PATCH v7 2/2] erofs-utils: lib: add API to iterate dirs in EROFS

[Gao Xiang]

Hi Kelvin,

On Fri, Dec 17, 2021 at 02:54:09PM -0500, Kelvin Zhang wrote:
> Hi Gao,
>     I drafted a new patchset on top of the dev branch. Changes since v6:
> 
>     1. block buffer moved to the heap, due to stack size concerns when
> iterating recursively
>     2. Added a "recursive" option to input parameters
>     3. dname buffers are still on the heap, but allocation is done once per
> directory, instead of once for each directory entry.
>     4. Added a void* arg which will be forwarded to the callback function.
> 
> I ran scripts/checkpatch.pl . Hopefully this makes your life easier. Thanks
> for the reply!.
> 
> 

Many thanks for your reply! I plan to take the patches in the
experimental branch.

The reason was written in include/erofs/dir.h:
https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs-utils.git/tree/include/erofs/dir.h?h=experimenta

 erofs_dir_context can be allocated on heap (in summary, by
 the caller) and chain together in order to avoid recursion
 totally later. I think it should benefit Android scenario to
 avoid stack overflow due to deep level as well.

Also Igor Eisberg sent a patch for a new get_pathname in the
erofs_dir_context reuse way:
 https://lore.kernel.org/linux-erofs/CABjEcnE84FNBgiHFk6Q+V3d-4L-93bUFDkdfN4ftPX19kpC=ww@mail.gmail.com/

I plan to polish and apply them as well.

Thanks,
Gao Xiang