Re: [Qemu-devel] [RFC V3 00/24] QCOW2 deduplication

[Stefan Hajnoczi]

On Mon, Nov 26, 2012 at 02:04:59PM +0100, Benoît Canet wrote:
> This patchset is the first working version of the QCOW2 deduplication.
> 
> Images must be created with "-o dedup=on" in order to activate the
> deduplication in the image.
> 
> 
> Since v2: make it work barely
>           replace kernel red black trees by gtree.
> 
> Benoît Canet (24):
>   qcow2: Add deduplication to the qcow2 specification.
>   qcow2: Add deduplication structures and fields.
>   qcow2: Add qcow2_dedup_read_missing_and_concatenate
>   qcow2: Make update_cluster_refcount public.
>   qcow2: Create a way to link to l2 tables in dedup.
>   qcow2: Add qcow2_dedup and related functions.
>   qcow2: Add qcow2_dedup_write_new_hashes.
>   qcow2: Implement qcow2_compute_cluster_hash.
>   qcow2: Extract qcow2_dedup_grow_table
>   qcow2: create function to load deduplication hashes at startup.
>   qcow2: Load and save deduplication table header extension.
>   qcow2: Extract qcow2_do_table_init.
>   qcow2: Add qcow2_dedup_init and qcow2_dedup_close.
>   qcow2: Extract qcow2_add_feature and qcow2_remove_feature.
>   block: Add dedup image create option.
>   qcow2: Allow creation of images using deduplication.
>   qcow2: Behave correctly when refcount reach 0 or 2^16.
>   qcow2: Integrate deduplication in qcow2_co_writev loop.
>   qcow2: Add verification of dedup table.
>   qcow2: Adapt checking of QCOW_OFLAG_COPIED for dedup.
>   qcow2: Add check_dedup_l2 in order to check l2 of dedup table.
>   qcow2: Do not overwrite existing entries with QCOW_OFLAG_COPIED.
>   qcow2: init and cleanup deduplication.
>   qemu-iotests: Filter dedup=on/off so existing tests don't break.
> 
>  Makefile                     |    3 +
>  Makefile.target              |    2 +-
>  block/Makefile.objs          |    1 +
>  block/qcow2-cluster.c        |  115 ++++--
>  block/qcow2-dedup.c          |  914 
> ++++++++++++++++++++++++++++++++++++++++++
>  block/qcow2-refcount.c       |  154 +++++--
>  block/qcow2.c                |  267 ++++++++++--
>  block/qcow2.h                |   89 +++-
>  block_int.h                  |    1 +
>  docs/specs/qcow2.txt         |   33 +-
>  tests/qemu-iotests/common.rc |    3 +-
>  11 files changed, 1480 insertions(+), 102 deletions(-)
>  create mode 100644 block/qcow2-dedup.c

$ make check
  LINK  tests/test-coroutine
/usr/bin/ld: block/qcow2-dedup.o: undefined reference to symbol 
'EVP_sha256@@libcrypto.so.10'
/usr/bin/ld: note: 'EVP_sha256@@libcrypto.so.10' is defined in DSO 
/lib64/libcrypto.so.10 so try adding it to the linker command line
/lib64/libcrypto.so.10: could not read symbols: Invalid operation
collect2: error: ld returned 1 exit status
make: *** [tests/test-coroutine] Error 1