btrfs: correct the assert for subpage case

[PATCH] btrfs: correct the assert for subpage case

Posted by Daniel Vacek 9 months ago

The assert is only true in !subpage case. We can either fix it this way
or completely remove it.

This fixes and should be folded into:
	btrfs: fix broken drop_caches on extent buffer folios

Signed-off-by: Daniel Vacek <neelx@suse.com>
---
 fs/btrfs/extent_io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 80a8563a25add..3b3f73894ffe2 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3411,7 +3411,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
 			continue;
 		}
 
-		ASSERT(!folio_test_private(folio));
+		ASSERT(!btrfs_meta_is_subpage(fs_info) && !folio_test_private(folio));
 		folio_put(folio);
 		eb->folios[i] = NULL;
 	}
-- 
2.47.2

Re: [PATCH] btrfs: correct the assert for subpage case

Posted by Qu Wenruo 9 months ago


在 2025/5/12 22:58, Daniel Vacek 写道:
> The assert is only true in !subpage case. We can either fix it this way
> or completely remove it.
> 
> This fixes and should be folded into:
> 	btrfs: fix broken drop_caches on extent buffer folios
> 
> Signed-off-by: Daniel Vacek <neelx@suse.com>

Looks good to me.

Although I agree with Boris, it's better to remove the ASSERT().
Subpage is no longer a corner/minor usage anymore, we shouldn't treat 
subpage and normal cases differently when possible.

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu

> ---
>   fs/btrfs/extent_io.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 80a8563a25add..3b3f73894ffe2 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -3411,7 +3411,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
>   			continue;
>   		}
>   
> -		ASSERT(!folio_test_private(folio));
> +		ASSERT(!btrfs_meta_is_subpage(fs_info) && !folio_test_private(folio));
>   		folio_put(folio);
>   		eb->folios[i] = NULL;
>   	}

Re: [PATCH] btrfs: correct the assert for subpage case

Posted by Boris Burkov 9 months ago

On Mon, May 12, 2025 at 03:28:50PM +0200, Daniel Vacek wrote:
> The assert is only true in !subpage case. We can either fix it this way
> or completely remove it.
> 
> This fixes and should be folded into:
> 	btrfs: fix broken drop_caches on extent buffer folios
> 
> Signed-off-by: Daniel Vacek <neelx@suse.com>

I would lean towards removing it, personally. But LGTM, thanks.

Reviewed-by: Boris Burkov <boris@bur.io>

> ---
>  fs/btrfs/extent_io.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index 80a8563a25add..3b3f73894ffe2 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -3411,7 +3411,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
>  			continue;
>  		}
>  
> -		ASSERT(!folio_test_private(folio));
> +		ASSERT(!btrfs_meta_is_subpage(fs_info) && !folio_test_private(folio));
>  		folio_put(folio);
>  		eb->folios[i] = NULL;
>  	}
> -- 
> 2.47.2
>

Re: [PATCH] btrfs: correct the assert for subpage case

Posted by Daniel Vacek 9 months ago

On Mon, 12 May 2025 at 19:53, Boris Burkov <boris@bur.io> wrote:
>
> On Mon, May 12, 2025 at 03:28:50PM +0200, Daniel Vacek wrote:
> > The assert is only true in !subpage case. We can either fix it this way
> > or completely remove it.
> >
> > This fixes and should be folded into:
> >       btrfs: fix broken drop_caches on extent buffer folios
> >
> > Signed-off-by: Daniel Vacek <neelx@suse.com>
>
> I would lean towards removing it, personally. But LGTM, thanks.

Good. Let's remove it then. Will you amend your patch?

> Reviewed-by: Boris Burkov <boris@bur.io>
>
> > ---
> >  fs/btrfs/extent_io.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> > index 80a8563a25add..3b3f73894ffe2 100644
> > --- a/fs/btrfs/extent_io.c
> > +++ b/fs/btrfs/extent_io.c
> > @@ -3411,7 +3411,7 @@ struct extent_buffer *alloc_extent_buffer(struct btrfs_fs_info *fs_info,
> >                       continue;
> >               }
> >
> > -             ASSERT(!folio_test_private(folio));
> > +             ASSERT(!btrfs_meta_is_subpage(fs_info) && !folio_test_private(folio));
> >               folio_put(folio);
> >               eb->folios[i] = NULL;
> >       }
> > --
> > 2.47.2
> >