Re: [PATCH] xfs/170: increase agsize for bigger internal log size

[Eryu Guan <guaneryu@gmail.com>]

On Mon, Jun 11, 2018 at 05:10:40PM +0800, Zorro Lang wrote:
> xfs/170 always fails on xfs with "-m rmapbt=1,reflink=1", because
> XFS need bigger internal log size if rmapbt and reflink are both
> enabled.
> 
> One line of xfs/170 as below:
> 
>   _test_streams 8 16 4 8 3 0 0
> 
> Refer to common/filestreams, we can see xfs/170 trys to create a
> 128M XFS (agcount=8, agsize=16M), then each stream writes
> 24M (8 * 3M files), and there're 4 streams.
> 
> So the case expects each stream takes 2 AGs, 4 streams takes
> different 8 AGs just enough. But internal log will break this
> balance. For example:
> 
> "mkfs.xfs -f -b size=4k -m rmapbt=1,reflink=1 $dev" will take 3075
> 4k blocks (12M) by default:
>   meta-data=/dev/mapper/xxxx-xfscratch isize=512    agcount=8, agsize=4096 blks
>   ...
>   log      =internal               bsize=4096   blocks=3075, version=2
>            =                       sectsz=512   sunit=0 blks, lazy-count=1
>   ...
> 
> And the internal log is in the 4th AG:
>   # xfs_logprint: /dev/mapper/xxxx-xfscratch
>   xfs_logprint:
>       data device: 0xfd03
>       log device: 0xfd03 daddr: 131120 length: 24600
>   # xfs_db -c "convert daddr 131120 agno" /dev/mapper/xxxx-xfscratch
>   0x4 (4)
> 
> Then if one stream write data into AG-1 at first, then turn to AG-4
> after fill 16M agsize. But AG-4 has 12M space for log section, so
> only 4M free space for data. Then this stream have to turn to the
> next AG after fill the 4M space. All these as below:
> 
>   # xfs_bmap -vp stream2-dir/*
>   stream2-dir/frame-1:
>    EXT: FILE-OFFSET      BLOCK-RANGE      AG AG-OFFSET        TOTAL FLAGS
>      0: [0..6143]:       32960..39103      1 (192..6335)       6144 000000
>   ...
>   ...
>   stream2-dir/frame-5:
>    EXT: FILE-OFFSET      BLOCK-RANGE      AG AG-OFFSET        TOTAL FLAGS
>      0: [0..6143]:       57536..63679      1 (24768..30911)    6144 000000
>   stream2-dir/frame-6:
>    EXT: FILE-OFFSET      BLOCK-RANGE      AG AG-OFFSET        TOTAL FLAGS
>      0: [0..6143]:       155776..161919    4 (24704..30847)    6144 000000
>   stream2-dir/frame-7:
>    EXT: FILE-OFFSET      BLOCK-RANGE      AG AG-OFFSET        TOTAL FLAGS
>      0: [0..6143]:       170088..176231    5 (6248..12391)     6144 000000
>   stream2-dir/frame-8:
>    EXT: FILE-OFFSET      BLOCK-RANGE      AG AG-OFFSET        TOTAL FLAGS
>      0: [0..6143]:       176232..182375    5 (12392..18535)    6144 000000
> 
> Later _test_streams maybe takes AG-5 again, and cause two streams use
> AG-5. To avoid this failure, increase the agsize from 16M to 22M,
> others stay the same, each stream still writes 2 AGs. Even internal
> log takes some space from someone AG, left space should be enough to
> write (24 - 22)=2M data.
> 
> Signed-off-by: Zorro Lang <zlang@redhat.com>

I may need some helps from xfs folks to review this patch :)

Thanks a lot!

Eryu

> ---
>  tests/xfs/170     | 9 ++++-----
>  tests/xfs/170.out | 8 ++++----
>  2 files changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/tests/xfs/170 b/tests/xfs/170
> index f82df69d..eb26764a 100755
> --- a/tests/xfs/170
> +++ b/tests/xfs/170
> @@ -42,11 +42,10 @@ _check_filestreams_support || _notrun "filestreams not available"
>  _set_stream_timeout_centisecs 3000
>  
>  # test streams does a mkfs and mount
> -_test_streams 8 16 4 8 3 0 0
> -_test_streams 8 16 4 8 3 1 0
> -_test_streams 8 16 4 8 3 0 1
> -_test_streams 8 16 4 8 3 1 1
> +_test_streams 8 22 4 8 3 0 0
> +_test_streams 8 22 4 8 3 1 0
> +_test_streams 8 22 4 8 3 0 1
> +_test_streams 8 22 4 8 3 1 1
>  
>  status=0
>  exit
> -
> diff --git a/tests/xfs/170.out b/tests/xfs/170.out
> index a1339cec..e71515e9 100644
> --- a/tests/xfs/170.out
> +++ b/tests/xfs/170.out
> @@ -1,20 +1,20 @@
>  QA output created by 170
> -# testing 8 16 4 8 3 0 0 ....
> +# testing 8 22 4 8 3 0 0 ....
>  # streaming
>  # sync AGs...
>  # checking stream AGs...
>  + passed, streams are in seperate AGs
> -# testing 8 16 4 8 3 1 0 ....
> +# testing 8 22 4 8 3 1 0 ....
>  # streaming
>  # sync AGs...
>  # checking stream AGs...
>  + passed, streams are in seperate AGs
> -# testing 8 16 4 8 3 0 1 ....
> +# testing 8 22 4 8 3 0 1 ....
>  # streaming
>  # sync AGs...
>  # checking stream AGs...
>  + passed, streams are in seperate AGs
> -# testing 8 16 4 8 3 1 1 ....
> +# testing 8 22 4 8 3 1 1 ....
>  # streaming
>  # sync AGs...
>  # checking stream AGs...
> -- 
> 2.14.4
> 
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