Re: [PATCH] btrfs: stop printing condition result in assertion failure messages

[David Sterba <dsterba@suse.cz>]

On Thu, Feb 19, 2026 at 03:45:39PM +0000, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> It's useless to print the result of the condition, it's always 0 if the
> assertion is triggered, so it doesn't provide any useful information.
> Examples:
> 
>    assertion failed: cb->bbio.bio.bi_iter.bi_size == disk_num_bytes :: 0, in inode.c:9991
>    assertion failed: folio_test_writeback(folio) :: 0, in subpage.c:476
> 
> So stop printing that, it's always ":: 0" for any assertion triggered.

I've put it there because of the single value conditions like

	ASSERT(flag);

In most cases the condition is compound and boolean so the result is not
useful and there are also many cases with simple pointer value so the
exact value is also not providing anything.

For any case we want to know exact values or possibly of subexpressions
too (like start + length or other calculations) we should use the
extended ASSERT syntax.


> Signed-off-by: Filipe Manana <fdmanana@suse.com>
> ---
>  fs/btrfs/messages.h | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/messages.h b/fs/btrfs/messages.h
> index 81f59afe4a99..17cdc14dc89d 100644
> --- a/fs/btrfs/messages.h
> +++ b/fs/btrfs/messages.h
> @@ -141,11 +141,11 @@ do {										\
>  	verify_assert_printk_format("check the format string" args);		\
>  	if (!likely(cond)) {							\

This should probably become "if (likely(!cond))" as mentioned recently.