erofs: convert to use i_blockmask()

[Yangtao Li]

Hi AI,

> Umm...  What's the branchpoint for that series?
> Not the mainline - there we have i_blocksize() open-coded...

Sorry, I'm based on the latest branch of the erofs repository.

https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git/log/?h=dev-test

I think I can resend based on mainline.

> Umm...  That actually asks for DIV_ROUND_UP(i_size_read_inode(), i_blocksize(inode))
> - compiler should bloody well be able to figure out that division by (1 << n)
> is shift down by n and it's easier to follow that way...

So it seems better to change to DIV_ROUND_UP(i_size_read_inode(), i_blocksize(inode))?

> And the fact that the value will be the same (i.e. that ->i_blkbits is never changed by ocfs2)
> is worth mentioning in commit message...

How about the following msg?

Use i_blockmask() to simplify code. BTW convert ocfs2_is_io_unaligned
to return bool type and the fact that the value will be the same
(i.e. that ->i_blkbits is never changed by ocfs2).



A small question, whether this series of changes will be merged
into each fs branch or all merged into vfs?

Thx,
Yangtao