On Mon, Sep 23, 2024 at 05:28:15PM +0200, Christoph Hellwig wrote:
> Split out a pice of logic from iomap_file_buffered_write_punch_delalloc
> that is useful for all iomap_end implementations.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/iomap/buffered-io.c | 13 ++-----------
> include/linux/iomap.h | 14 ++++++++++++++
> 2 files changed, 16 insertions(+), 11 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 11ea747228aeec..884891ac7a226c 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -1280,7 +1280,6 @@ void iomap_file_buffered_write_punch_delalloc(struct inode *inode,
> {
> loff_t start_byte;
> loff_t end_byte;
> - unsigned int blocksize = i_blocksize(inode);
>
> if (iomap->type != IOMAP_DELALLOC)
> return;
> @@ -1289,16 +1288,8 @@ void iomap_file_buffered_write_punch_delalloc(struct inode *inode,
> if (!(iomap->flags & IOMAP_F_NEW))
> return;
>
> - /*
> - * start_byte refers to the first unused block after a short write. If
> - * nothing was written, round offset down to point at the first block in
> - * the range.
> - */
> - if (unlikely(!written))
> - start_byte = round_down(pos, blocksize);
> - else
> - start_byte = round_up(pos + written, blocksize);
> - end_byte = round_up(pos + length, blocksize);
> + start_byte = iomap_last_written_block(inode, pos, written);
> + end_byte = round_up(pos + length, i_blocksize(inode));
>
> /* Nothing to do if we've written the entire delalloc extent */
> if (start_byte >= end_byte)
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 4ad12a3c8bae22..e62df5d93f04de 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -256,6 +256,20 @@ static inline const struct iomap *iomap_iter_srcmap(const struct iomap_iter *i)
> return &i->iomap;
> }
>
> +/*
> + * Return the file offset for the first unused block after a short write.
the first *unchanged* block after a short write?
> + *
> + * If nothing was written, round offset down to point at the first block in
Might as well make explicit which variable we're operating on:
"...round @pos down..."
--D
> + * the range, else round up to include the partially written block.
> + */
> +static inline loff_t iomap_last_written_block(struct inode *inode, loff_t pos,
> + ssize_t written)
> +{
> + if (unlikely(!written))
> + return round_down(pos, i_blocksize(inode));
> + return round_up(pos + written, i_blocksize(inode));
> +}
> +
> ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
> const struct iomap_ops *ops, void *private);
> int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops);
> --
> 2.45.2
>
