Re: [PATCH 8/8] Fix btrfs/106 to work on non-4k page sized machines

Filipe Manana
2015-12-10T17:28:35Z

On Mon, Nov 30, 2015 at 10:17 AM, Chandan Rajendra
<chandan@linux.vnet.ibm.com> wrote:
> This commit makes use of the new _filter_xfs_io_pages_modified filtering
> function to print information in terms of page size units rather than file
> offset.
>
> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>

Thanks!

> ---
> tests/btrfs/106 | 36 ++++++++++++++++++++----------------
> tests/btrfs/106.out | 30 ++++++++++++++++++------------
> 2 files changed, 38 insertions(+), 28 deletions(-)
>
> diff --git a/tests/btrfs/106 b/tests/btrfs/106
> index 1670453..30c43fa 100755
> --- a/tests/btrfs/106
> +++ b/tests/btrfs/106
> @@ -58,31 +58,35 @@ test_clone_and_read_compressed_extent()
> _scratch_mkfs >>$seqres.full 2>&1
> _scratch_mount $mount_opts
>
> - # Create our test file with a single extent of 64Kb that is going to be
> - # compressed no matter which compression algorithm is used (zlib/lzo).
> - $XFS_IO_PROG -f -c "pwrite -S 0xaa 0K 64K" \
> - $SCRATCH_MNT/foo | _filter_xfs_io
> + PAGE_SIZE=$(get_page_size)
> +
> + # Create our test file with 16 pages worth of data in a single extent
> + # that is going to be compressed no matter which compression algorithm
> + # is used (zlib/lzo).
> + $XFS_IO_PROG -f -c "pwrite -S 0xaa 0K $((16 * $PAGE_SIZE))" \
> + $SCRATCH_MNT/foo | _filter_xfs_io_pages_modified
>
> # Now clone the compressed extent into an adjacent file offset.
> - $CLONER_PROG -s 0 -d $((64 * 1024)) -l $((64 * 1024)) \
> + $CLONER_PROG -s 0 -d $((16 * $PAGE_SIZE)) -l $((16 * $PAGE_SIZE)) \
> $SCRATCH_MNT/foo $SCRATCH_MNT/foo
>
> - echo "File digest before unmount:"
> - md5sum $SCRATCH_MNT/foo | _filter_scratch
> + echo "File contents before unmount:"
> + od -t x1 $SCRATCH_MNT/foo | _filter_od
>
> # Remount the fs or clear the page cache to trigger the bug in btrfs.
> - # Because the extent has an uncompressed length that is a multiple of
> - # 16 pages, all the pages belonging to the second range of the file
> - # (64K to 128K), which points to the same extent as the first range
> - # (0K to 64K), had their contents full of zeroes instead of the byte
> - # 0xaa. This was a bug exclusively in the read path of compressed
> - # extents, the correct data was stored on disk, btrfs just failed to
> - # fill in the pages correctly.
> + # Because the extent has an uncompressed length that is a multiple of 16
> + # pages, all the pages belonging to the second range of the file that is
> + # mapped by the page index range [16, 31], which points to the same
> + # extent as the first file range mapped by the page index range [0, 15],
> + # had their contents full of zeroes instead of the byte 0xaa. This was a
> + # bug exclusively in the read path of compressed extents, the correct
> + # data was stored on disk, btrfs just failed to fill in the pages
> + # correctly.
> _scratch_remount
>
> - echo "File digest after remount:"
> + echo "File contents after remount:"
> # Must match the digest we got before.
> - md5sum $SCRATCH_MNT/foo | _filter_scratch
> + od -t x1 $SCRATCH_MNT/foo | _filter_od
> }
>
> echo -e "\nTesting with zlib compression..."
> diff --git a/tests/btrfs/106.out b/tests/btrfs/106.out
> index 692108d..1144a82 100644
> --- a/tests/btrfs/106.out
> +++ b/tests/btrfs/106.out
> @@ -1,17 +1,23 @@
> QA output created by 106
>
> Testing with zlib compression...
> -wrote 65536/65536 bytes at offset 0
> -XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> -File digest before unmount:
> -be68df46e3cf60b559376a35f9fbb05d SCRATCH_MNT/foo
> -File digest after remount:
> -be68df46e3cf60b559376a35f9fbb05d SCRATCH_MNT/foo
> +Pages modified: [0 - 15]
> +File contents before unmount:
> +0 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
> +*
> +40
> +File contents after remount:
> +0 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
> +*
> +40
>
> Testing with lzo compression...
> -wrote 65536/65536 bytes at offset 0
> -XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
> -File digest before unmount:
> -be68df46e3cf60b559376a35f9fbb05d SCRATCH_MNT/foo
> -File digest after remount:
> -be68df46e3cf60b559376a35f9fbb05d SCRATCH_MNT/foo
> +Pages modified: [0 - 15]
> +File contents before unmount:
> +0 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
> +*
> +40
> +File contents after remount:
> +0 aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa aa
> +*
> +40
> --
> 2.1.0
>
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--
Filipe David Manana,

"Reasonable men adapt themselves to the world.
Unreasonable men adapt the world to themselves.
That's why all progress depends on unreasonable men."