Backport erofs to kernel 4.9

[donmark8]

Do you know if erofs is backported to kernel 4.9? If not, how difficult to do that? Thanks

[hsiangkao]

my previous employer once had in-house 4.9 erofs products, but that is quite old.

https://download-c1.huawei.com/download/downloadCenter?downloadId=101094&version=438732&siteCode=worldwide Hulk-AL10E_PIE

anyway, 4.9 kernel is too old for me to consider, we're in 5.19 cycle now.

[donmark8]

Thank you so much for the link, it's very helpful. The reason I would like to try 4.9 erofs is we still use kernel 4.9 in our products. Really appreciate your help!

[hsiangkao]

Thank you so much for the link, it's very helpful. The reason I would like to try 4.9 erofs is we still use kernel 4.9 in our products. Really appreciate your help!

Yet that erofs was a very old on-disk format... should be used with care...

[donmark8]

Thank you for your advice. You are right, after I added that 4.9 erofs in our platform, I was able to mount a file created by using mkfs.erofs 1.0 under ubuntu 20.04, but got Input/output error when trying to access the mounted directory, it looked like the format is not compatible. I am going to backport more the latest patches to 4.9, see if I can make it compatible with at least mkfs.erofs 1.0.

BTW. Is that possible to backport EROFS to kernel 4.4 or 3.10? We have devices running on very old kernel, and those old platforms really need to improve the performance. Do you happen to have the backport for those kernels?

[hsiangkao]

Thank you for your advice. You are right, after I added that 4.9 erofs in our platform, I was able to mount a file created by using mkfs.erofs 1.0 under ubuntu 20.04, but got Input/output error when trying to access the mounted directory, it looked like the format is not compatible. I am going to backport more the latest patches to 4.9, see if I can make it compatible with at least mkfs.erofs 1.0.

BTW. Is that possible to backport EROFS to kernel 4.4 or 3.10? We have devices running on very old kernel, and those old platforms really need to improve the performance. Do you happen to have the backport for those kernels?

... I don't think these can happen ever, anyway, I mostly focus on the mainline kernel. Old kernels are really out of scope for me...

[xiao-k233]

谢谢你的建议。你是对的，在我的平台中添加了 4.9 erofs 后，我能够在 ubuntu 20.04 下挂载使用 mkfs.erofs 1.0 创建的文件，但在尝试访问挂载目录时出现输入/输出错误，看起来格式不兼容。我将把更多最新的补丁向后移植到 4.9，看看我是否可以使其至少与 mkfs.erofs 1.0 兼容。

顺便说一句。是否可以将 EROFS 向后移植到内核 4.4 或 3.10？我们的设备运行在非常旧的内核上，而那些旧平台确实需要提高性能。您是否碰巧有这些内核的向后移植？

so，can you share your 4.9 backport?