Re: [PATCH] erofs-utils: fsck: add concurrent extraction and decompression

[Gao Xiang <hsiangkao@linux.alibaba.com>]

On 2026/7/2 20:59, Nithurshen Karthikeyan wrote:
> On Thu, 2 Jul, 2026, 18:24 Gao Xiang, <hsiangkao@linux.alibaba.com> wrote:
> 
>>
>>
>> On 2026/7/2 16:10, Nithurshen wrote:
>>> This patch introduces a multi-threaded pipeline for fsck.erofs,
>>> combining parallel directory traversal with background pcluster
>>> decompression to significantly reduce extraction time.
>>>
>>> Key architectural changes include:
>>>
>>> - Thread-Safe State: Removes the global dirstack array and
>>>     fsckcfg.extract_path. These are replaced with per-task localized
>>>     paths and thread-local linked lists to eliminate data races.
>>> - Concurrent Traversal: Refactors erofsfsck_dirent_iter to allocate
>>>     task structures and dispatch inode processing to a background
>>>     workqueue (z_erofs_mt_wq).
>>> - Asynchronous Decompression: Introduces z_erofs_mt_read_ctx to
>>>     batch pcluster reads and decouple decompression from main I/O.
>>>     Limits batch size dynamically (32 for LZ4, 8 for compute-heavy
>>>     algorithms) to balance CPU cache hits and memory overhead.
>>> - Memory & Deadlock Safety: Implements inline backpressure during
>>>     directory iteration. If pending inodes exceed workqueue capacity,
>>>     execution falls back to synchronous processing to prevent
>>>     recursive thread-pool starvation and unbounded memory growth.
>>> - Synchronization Primitives: Adds portable condition variable
>>>     wrappers (erofs_cond_t) to ensure the main thread safely waits
>>>     for all pending background inodes before exiting.
>>>
>>> Signed-off-by: Nithurshen <nithurshen.dev@gmail.com>
>>
>> What's the relationship with the previous two patches?
>>
> 
> I made then into one atomic patch, since you wanted them merged at once.

Nope, I didn't want that, I suggested you benchmark each patch.
But it doesn't mean the patches should be merged.

The merge meant merging commits to erofs-utils.

Thanks,
Gao Xiang

> 
> Thanks,
> Nithurshen
> 
> Thanks,
>> Gao Xiang
>>
>