Re: [PATCH v3] btrfs-progs: receive: fix unused variable warning without LZO

[Qu Wenruo <wqu@suse.com>]

在 2026/9/30 16:13, liuh0329 写道:
> When btrfs-progs is built without LZO support, sector_shift is still
> declared in decompress_and_write(), while all its uses are guarded by
> COMPRESSION_LZO. This results in an unused variable warning.
> 
> Move the sector_shift declaration to the LZO-specific code path so it is
> only declared when LZO support is enabled.
> 
> Fixes: 345731fff32d ("btrfs-progs: receive: optional build for lzo, zstd")
> Signed-off-by: liuh0329 <liuhuan01@kylinos.cn>

Reviewed-by: Qu Wenruo <wqu@suse.com>
> ---
> Changes in v3:
> - Drop the extra scope and move sector_shift declaration directly to its
>    only usage as suggested by Qu Wenruo.

Next time please use more common sense, less brain dead "vibe" coding.

> 
> Changes in v2:
> - Move sector_shift declaration to its only usage, as suggested by Qu Wenruo.
> - Add a local scope for sector_shift.
> 
>   cmds/receive.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/cmds/receive.c b/cmds/receive.c
> index 49103ea3..f592a044 100644
> --- a/cmds/receive.c
> +++ b/cmds/receive.c
> @@ -1186,7 +1186,6 @@ static int decompress_and_write(struct btrfs_receive *rctx,
>   {
>   	int ret = 0;
>   	char *unencoded_data;
> -	int sector_shift = 0;
>   	u64 written = 0;
>   
>   	unencoded_data = calloc(unencoded_len, 1);
> @@ -1220,7 +1219,7 @@ static int decompress_and_write(struct btrfs_receive *rctx,
>   	case BTRFS_ENCODED_IO_COMPRESSION_LZO_32K:
>   	case BTRFS_ENCODED_IO_COMPRESSION_LZO_64K:
>   #if COMPRESSION_LZO
> -		sector_shift =
> +		int sector_shift =
>   			compression - BTRFS_ENCODED_IO_COMPRESSION_LZO_4K + 12;
>   		ret = decompress_lzo(encoded_data, encoded_len, unencoded_data,
>   				     unencoded_len, 1U << sector_shift);