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Date: Wed, 18 Oct 2023 17:57:32 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Wedson Almeida Filho <wedsonaf@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
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	Wedson Almeida Filho <walmeida@microsoft.com>
Subject: Re: [RFC PATCH 19/19] tarfs: introduce tar fs
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	lindbergh.monkeyblade.net

On Wed, Oct 18, 2023 at 09:25:18AM -0300, Wedson Almeida Filho wrote:
> +    fn read_folio(inode: &INode<Self>, mut folio: LockedFolio<'_>) -> Result {
> +        let pos = u64::try_from(folio.pos()).unwrap_or(u64::MAX);
> +        let size = u64::try_from(inode.size())?;
> +        let sb = inode.super_block();
> +
> +        let copied = if pos >= size {
> +            0
> +        } else {
> +            let offset = inode.data().offset.checked_add(pos).ok_or(ERANGE)?;
> +            let len = core::cmp::min(size - pos, folio.size().try_into()?);
> +            let mut foffset = 0;
> +
> +            if offset.checked_add(len).ok_or(ERANGE)? > sb.data().data_size {
> +                return Err(EIO);
> +            }
> +
> +            for v in sb.read(offset, len)? {
> +                let v = v?;
> +                folio.write(foffset, v.data())?;
> +                foffset += v.data().len();
> +            }
> +            foffset
> +        };
> +
> +        folio.zero_out(copied, folio.size() - copied)?;
> +        folio.mark_uptodate();
> +        folio.flush_dcache();
> +
> +        Ok(())
> +    }

Who unlocks the folio here?