Re: git: d09a955a605d - main - zfs: Fix positive ABD size assertion in abd_verify().

I found it as part of some new development and never saw it triggered 
otherwise, so AFAIK it didn't require any urgency.

On 26.04.2023 14:01, Mateusz Guzik wrote:
> The branch main has been updated by mjg:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=d09a955a605d03471c5ab7bd17b8a6186fdc148c
> 
> commit d09a955a605d03471c5ab7bd17b8a6186fdc148c
> Author:     Mateusz Guzik <mjg@FreeBSD.org>
> AuthorDate: 2023-04-26 17:59:24 +0000
> Commit:     Mateusz Guzik <mjg@FreeBSD.org>
> CommitDate: 2023-04-26 18:00:36 +0000
> 
>      zfs: Fix positive ABD size assertion in abd_verify().
>      
>      This cherry-picks upstream:
>      commit bba7cbf0a481ab16f9a9a4874b7dbd5682e4d3a4
>      Author: Alexander Motin <mav@FreeBSD.org>
>      Date:   Wed Apr 26 12:20:43 2023 -0400
>      
>          Fix positive ABD size assertion in abd_verify().
>      
>          Gang ABDs without childred are legal, and they do have zero size.
>          For other ABD types zero size doesn't have much sense and likely
>          not working correctly now.
>      
>          Reviewed-by: Igor Kozhukhov <igor@dilos.org>
>          Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
>          Signed-off-by:  Alexander Motin <mav@FreeBSD.org>
>          Sponsored by:   iXsystems, Inc.
>          Closes #14795
>      
>      Sponsored by:   Rubicon Communications, LLC ("Netgate")
> ---
>   sys/contrib/openzfs/module/zfs/abd.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sys/contrib/openzfs/module/zfs/abd.c b/sys/contrib/openzfs/module/zfs/abd.c
> index d4921d0ba7db..26222d2efe3f 100644
> --- a/sys/contrib/openzfs/module/zfs/abd.c
> +++ b/sys/contrib/openzfs/module/zfs/abd.c
> @@ -109,7 +109,6 @@ void
>   abd_verify(abd_t *abd)
>   {
>   #ifdef ZFS_DEBUG
> -	ASSERT3U(abd->abd_size, >, 0);
>   	ASSERT3U(abd->abd_size, <=, SPA_MAXBLOCKSIZE);
>   	ASSERT3U(abd->abd_flags, ==, abd->abd_flags & (ABD_FLAG_LINEAR |
>   	    ABD_FLAG_OWNER | ABD_FLAG_META | ABD_FLAG_MULTI_ZONE |
> @@ -118,6 +117,7 @@ abd_verify(abd_t *abd)
>   	IMPLY(abd->abd_parent != NULL, !(abd->abd_flags & ABD_FLAG_OWNER));
>   	IMPLY(abd->abd_flags & ABD_FLAG_META, abd->abd_flags & ABD_FLAG_OWNER);
>   	if (abd_is_linear(abd)) {
> +		ASSERT3U(abd->abd_size, >, 0);
>   		ASSERT3P(ABD_LINEAR_BUF(abd), !=, NULL);
>   	} else if (abd_is_gang(abd)) {
>   		uint_t child_sizes = 0;
> @@ -130,6 +130,7 @@ abd_verify(abd_t *abd)
>   		}
>   		ASSERT3U(abd->abd_size, ==, child_sizes);
>   	} else {
> +		ASSERT3U(abd->abd_size, >, 0);
>   		abd_verify_scatter(abd);
>   	}
>   #endif

-- 
Alexander Motin