Re: [PATCH v2] btrfs: fix _require_btrfs_send_version to detect btrfs-progs support

[Anand Jain <anand.jain@oracle.com>]

On 12/07/2024 17:54, fdmanana@kernel.org wrote:
> From: Filipe Manana <fdmanana@suse.com>
> 
> Commit 199d0a992536df3702a0c4843d2a449d54f399c2 ("common/btrfs: introduce
> _require_btrfs_send_version") turned _require_btrfs_send_v2 into a generic
> helper to detect support for any send stream version, however it's only
> working for detecting kernel support, it misses detecting the support from
> btrfs-progs - it always checks only that it supports v2 (the send command
> supports the --compressed-data option).
> 
> Fix that by verifying that btrfs-progs supports the requested version.
> 
> Reviewed-by: Qu Wenruo <wqu@suse.com>
> Signed-off-by: Filipe Manana <fdmanana@suse.com>
> ---
> 
> V2: Don't use -f /dev/null in the send command, just redirect stdout and
>      stderr to /dev/null.
>      Add Qu's review tag.
> 

Reviewed-by: Anand Jain <anand.jain@oracle.com>

Applied.

Thanks, Anand


>   common/btrfs | 20 ++++++++++++++++----
>   1 file changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/common/btrfs b/common/btrfs
> index be5948db..c0be7c08 100644
> --- a/common/btrfs
> +++ b/common/btrfs
> @@ -777,17 +777,29 @@ _require_btrfs_corrupt_block()
>   _require_btrfs_send_version()
>   {
>   	local version=$1
> +	local ret
>   
> -	# Check first if btrfs-progs supports the v2 stream.
> -	_require_btrfs_command send --compressed-data
> -
> -	# Now check the kernel support. If send_stream_version does not exists,
> +	# Check the kernel support. If send_stream_version does not exists,
>   	# then it's a kernel that only supports v1.
>   	[ -f /sys/fs/btrfs/features/send_stream_version ] || \
>   		_notrun "kernel does not support send stream $version"
>   
>   	[ $(cat /sys/fs/btrfs/features/send_stream_version) -ge $version ] || \
>   		_notrun "kernel does not support send stream $version"
> +
> +	# Now check that btrfs-progs supports the requested stream version.
> +	_scratch_mkfs &> /dev/null || \
> +		_fail "mkfs failed at _require_btrfs_send_version"
> +	_scratch_mount
> +	$BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT \
> +			 $SCRATCH_MNT/snap &> /dev/null
> +	$BTRFS_UTIL_PROG send --proto $version $SCRATCH_MNT/snap &> /dev/null
> +	ret=$?
> +	_scratch_unmount
> +
> +	if [ $ret -ne 0 ]; then
> +		_notrun "btrfs-progs does not support send stream version $version"
> +	fi
>   }
>   
>   # Get the bytenr associated to a file extent item at a given file offset.