From: Jinliang Zheng <alexjlzheng@tencent.com>

iomap_folio_state marks the uptodate state in units of block_size, so
it is better to check that pos and length are aligned with block_size.

Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
---
 fs/iomap/buffered-io.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index fd827398afd2..934458850ddb 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -234,6 +234,9 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
 	unsigned first = poff >> block_bits;
 	unsigned last = (poff + plen - 1) >> block_bits;
 
+	BUG_ON(*pos & (block_size - 1));
+	BUG_ON(length & (block_size - 1));
+
 	/*
 	 * If the block size is smaller than the page size, we need to check the
 	 * per-block uptodate status and adjust the offset and length if needed
-- 
2.49.0

Hi Jinliang,

On Mon, 11 Aug 2025 at 18:49, <alexjlzheng@gmail.com> wrote:
> From: Jinliang Zheng <alexjlzheng@tencent.com>
>
> iomap_folio_state marks the uptodate state in units of block_size, so
> it is better to check that pos and length are aligned with block_size.
>
> Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>

Thanks for your patch!

> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -234,6 +234,9 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
>         unsigned first = poff >> block_bits;
>         unsigned last = (poff + plen - 1) >> block_bits;
>
> +       BUG_ON(*pos & (block_size - 1));
> +       BUG_ON(length & (block_size - 1));

!IS_ALIGNED(...)

> +
>         /*
>          * If the block size is smaller than the page size, we need to check the
>          * per-block uptodate status and adjust the offset and length if needed

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

On Sun, Aug 10, 2025 at 06:15:51PM +0800, alexjlzheng@gmail.com wrote:
> From: Jinliang Zheng <alexjlzheng@tencent.com>
> 
> iomap_folio_state marks the uptodate state in units of block_size, so
> it is better to check that pos and length are aligned with block_size.
> 
> Signed-off-by: Jinliang Zheng <alexjlzheng@tencent.com>
> ---
>  fs/iomap/buffered-io.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index fd827398afd2..934458850ddb 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -234,6 +234,9 @@ static void iomap_adjust_read_range(struct inode *inode, struct folio *folio,
>  	unsigned first = poff >> block_bits;
>  	unsigned last = (poff + plen - 1) >> block_bits;
>  
> +	BUG_ON(*pos & (block_size - 1));
> +	BUG_ON(length & (block_size - 1));

We should not add BUG_ON calls like this, please turn these into
WARN_ON_ONCE instead.