On Fri, May 27, 2022 at 10:19:06AM +0200, Christoph Hellwig wrote:
> Add a few helpers to consolidate code for btrfs read repair testing:
>
> - _btrfs_get_first_logical() gets the btrfs logical address for the
> first extent in a file
> - _btrfs_get_device_path and _btrfs_get_physical use the
> btrfs-map-logical tool to find the device path and physical address
> for btrfs logical address for a specific mirror
> - _btrfs_direct_read_on_mirror and _btrfs_buffered_read_on_mirror
> read the data from a specific mirror
>
> These will be used to consolidate the read repair tests and avoid
> duplication for new tests.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
> ---
> common/btrfs | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++
> common/config | 1 +
> 2 files changed, 76 insertions(+)
>
> diff --git a/common/btrfs b/common/btrfs
> index ac597ca4..b69feeee 100644
> --- a/common/btrfs
> +++ b/common/btrfs
> @@ -505,3 +505,78 @@ _btrfs_metadump()
> $BTRFS_IMAGE_PROG "$device" "$dumpfile"
> [ -n "$DUMP_COMPRESSOR" ] && $DUMP_COMPRESSOR -f "$dumpfile" &> /dev/null
> }
> +
> +# Return the btrfs logical address for the first block in a file
> +_btrfs_get_first_logical()
> +{
> + local file=$1
> + _require_command "$FILEFRAG_PROG" filefrag
> +
> + ${FILEFRAG_PROG} -v $SCRATCH_MNT/foobar >> $seqres.full
^^
$file
You can send a single fixed patch for this one
Thanks,
Zorro
> + ${FILEFRAG_PROG} -v $file | _filter_filefrag | cut -d '#' -f 1
> +}
> +
> +# Find the device path for a btrfs logical offset
> +_btrfs_get_device_path()
> +{
> + local logical=$1
> + local stripe=$2
> +
> + _require_command "$BTRFS_MAP_LOGICAL_PROG" btrfs-map-logical
> +
> + $BTRFS_MAP_LOGICAL_PROG -l $logical $SCRATCH_DEV | \
> + $AWK_PROG "(\$1 ~ /mirror/ && \$2 ~ /$stripe/) { print \$8 }"
> +}
> +
> +
> +# Find the device physical sector for a btrfs logical offset
> +_btrfs_get_physical()
> +{
> + local logical=$1
> + local stripe=$2
> +
> + _require_command "$BTRFS_MAP_LOGICAL_PROG" btrfs-map-logical
> +
> + $BTRFS_MAP_LOGICAL_PROG -b -l $logical $SCRATCH_DEV >> $seqres.full 2>&1
> + $BTRFS_MAP_LOGICAL_PROG -l $logical $SCRATCH_DEV | \
> + $AWK_PROG "(\$1 ~ /mirror/ && \$2 ~ /$stripe/) { print \$6 }"
> +}
> +
> +# Read from a specific stripe to test read recovery that corrupted a specific
> +# stripe. Btrfs uses the PID to select the mirror, so keep reading until the
> +# xfs_io process that performed the read was executed with a PID that ends up
> +# on the intended mirror.
> +_btrfs_direct_read_on_mirror()
> +{
> + local mirror=$1
> + local nr_mirrors=$2
> + local file=$3
> + local offset=$4
> + local size=$5
> +
> + while [[ -z $( (( BASHPID % nr_mirrors == mirror )) &&
> + exec $XFS_IO_PROG -d \
> + -c "pread -b $size $offset $size" $file) ]]; do
> + :
> + done
> +}
> +
> +# Read from a specific stripe to test read recovery that corrupted a specific
> +# stripe. Btrfs uses the PID to select the mirror, so keep reading until the
> +# xfs_io process that performed the read was executed with a PID that ends up
> +# on the intended mirror.
> +_btrfs_buffered_read_on_mirror()
> +{
> + local mirror=$1
> + local nr_mirrors=$2
> + local file=$3
> + local offset=$4
> + local size=$5
> +
> + echo 3 > /proc/sys/vm/drop_caches
> + while [[ -z $( (( BASHPID % nr_mirrors == mirror )) &&
> + exec $XFS_IO_PROG \
> + -c "pread -b $size $offset $size" $file) ]]; do
> + :
> + done
> +}
> diff --git a/common/config b/common/config
> index c6428f90..df20afc1 100644
> --- a/common/config
> +++ b/common/config
> @@ -228,6 +228,7 @@ export E2IMAGE_PROG="$(type -P e2image)"
> export BLKZONE_PROG="$(type -P blkzone)"
> export GZIP_PROG="$(type -P gzip)"
> export BTRFS_IMAGE_PROG="$(type -P btrfs-image)"
> +export BTRFS_MAP_LOGICAL_PROG=$(type -P btrfs-map-logical)
>
> # use 'udevadm settle' or 'udevsettle' to wait for lv to be settled.
> # newer systems have udevadm command but older systems like RHEL5 don't.
> --
> 2.30.2
>
