btrfs: get rid of goto in alloc_test_extent_buffer()

[PATCH] btrfs: get rid of goto in alloc_test_extent_buffer()

Posted by Daniel Vacek 9 months, 2 weeks ago

The `free_eb` label is used only once. Simplify by moving the code inplace.

Signed-off-by: Daniel Vacek <neelx@suse.com>
---
 fs/btrfs/extent_io.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index ea38c73d4bc5f..20cdddd924852 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3004,15 +3004,13 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 			goto again;
 		}
 		xa_unlock_irq(&fs_info->buffer_tree);
-		goto free_eb;
+		btrfs_release_extent_buffer(eb);
+		return exists;
 	}
 	xa_unlock_irq(&fs_info->buffer_tree);
 	check_buffer_tree_ref(eb);
 
 	return eb;
-free_eb:
-	btrfs_release_extent_buffer(eb);
-	return exists;
 #else
 	/* Stub to avoid linker error when compiled with optimizations turned off. */
 	return NULL;
-- 
2.47.2

Re: [PATCH] btrfs: get rid of goto in alloc_test_extent_buffer()

Posted by David Sterba 9 months, 2 weeks ago

On Fri, Apr 25, 2025 at 09:23:57AM +0200, Daniel Vacek wrote:
> The `free_eb` label is used only once. Simplify by moving the code inplace.
> 
> Signed-off-by: Daniel Vacek <neelx@suse.com>
> ---
>  fs/btrfs/extent_io.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> index ea38c73d4bc5f..20cdddd924852 100644
> --- a/fs/btrfs/extent_io.c
> +++ b/fs/btrfs/extent_io.c
> @@ -3004,15 +3004,13 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
>  			goto again;
>  		}
>  		xa_unlock_irq(&fs_info->buffer_tree);
> -		goto free_eb;
> +		btrfs_release_extent_buffer(eb);
> +		return exists;
>  	}
>  	xa_unlock_irq(&fs_info->buffer_tree);
>  	check_buffer_tree_ref(eb);
>  
>  	return eb;
> -free_eb:
> -	btrfs_release_extent_buffer(eb);

So the xarray conversion removed the other use of the free_eb label and
calls btrfs_release_extent_buffer() + return. Doing the same here and
removing the label completely looks as an improvement, as the whole
function does direct returns instead of goto exit block.

Reviewed-by: David Sterba <dsterba@suse.com>

Re: [PATCH] btrfs: get rid of goto in alloc_test_extent_buffer()

Posted by David Sterba 9 months, 1 week ago

On Fri, Apr 25, 2025 at 01:39:07PM +0200, David Sterba wrote:
> On Fri, Apr 25, 2025 at 09:23:57AM +0200, Daniel Vacek wrote:
> > The `free_eb` label is used only once. Simplify by moving the code inplace.
> > 
> > Signed-off-by: Daniel Vacek <neelx@suse.com>
> > ---
> >  fs/btrfs/extent_io.c | 6 ++----
> >  1 file changed, 2 insertions(+), 4 deletions(-)
> > 
> > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
> > index ea38c73d4bc5f..20cdddd924852 100644
> > --- a/fs/btrfs/extent_io.c
> > +++ b/fs/btrfs/extent_io.c
> > @@ -3004,15 +3004,13 @@ struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
> >  			goto again;
> >  		}
> >  		xa_unlock_irq(&fs_info->buffer_tree);
> > -		goto free_eb;
> > +		btrfs_release_extent_buffer(eb);
> > +		return exists;
> >  	}
> >  	xa_unlock_irq(&fs_info->buffer_tree);
> >  	check_buffer_tree_ref(eb);
> >  
> >  	return eb;
> > -free_eb:
> > -	btrfs_release_extent_buffer(eb);
> 
> So the xarray conversion removed the other use of the free_eb label and
> calls btrfs_release_extent_buffer() + return. Doing the same here and
> removing the label completely looks as an improvement, as the whole
> function does direct returns instead of goto exit block.
> 
> Reviewed-by: David Sterba <dsterba@suse.com>

Xarray conversion is now in for-next so I've added this patch too.