Am Mo., 26. Juli 2021 um 14:17 Uhr schrieb Christoph Hellwig <hch@xxxxxx>:
>
> > Subject: iomap: Support tail packing
>
> I can't say I like this "tail packing" language here when we have the
> perfectly fine inline wording. Same for various comments in the actual
> code.
>
> > + /* inline and tail-packed data must start page aligned in the file */
> > + if (WARN_ON_ONCE(offset_in_page(iomap->offset)))
> > + return -EIO;
> > + if (WARN_ON_ONCE(size > PAGE_SIZE - offset_in_page(iomap->inline_data)))
> > + return -EIO;
>
> Why can't we use iomap_inline_data_size_valid here?
We can now. Gao, can you change that?
> That is how can size be different from iomap->length?
Quoting from my previous reply,
"In the iomap_readpage case (iomap_begin with flags == 0),
iomap->length will be the amount of data up to the end of the inode.
In the iomap_file_buffered_write case (iomap_begin with flags ==
IOMAP_WRITE), iomap->length will be the size of iomap->inline_data.
(For extending writes, we need to write beyond the current end of
inode.) So iomap->length isn't all that useful for
iomap_read_inline_data."
> Shouldn't the offset_in_page also go into iomap_inline_data_size_valid,
> which should probably be called iomap_inline_data_valid then?
Hmm, not sure what you mean: iomap_inline_data_size_valid does take
offset_in_page(iomap->inline_data) into account.
> > if (iomap->type == IOMAP_INLINE) {
> > + int ret = iomap_read_inline_data(inode, page, iomap);
> > + return ret ?: PAGE_SIZE;
>
> The ?: expression without the first leg is really confuing. Especially
> if a good old if is much more readable here.
I'm sure Gao can change this.
> int ret = iomap_read_inline_data(inode, page, iomap);
>
> if (ret)
> return ret;
> return PAGE_SIZE;
>
> > + copied = copy_from_iter(iomap_inline_data(iomap, pos), length, iter);
>
>
> > + copied = copy_to_iter(iomap_inline_data(iomap, pos), length, iter);
>
> Pleae avoid the overly long lines.
I thought people were okay with 80 character long lines?
Thanks,
Andreas
