Re: [Qemu-devel] [PATCH V19 00/10] libqblock qemu block layer library

[Stefan Hajnoczi]

On Sat, Feb 16, 2013 at 10:48:07AM +0800, Wenchao Xia wrote:
>   These patches introduce libqblock API, make subdir-libqblock and make
> check-libqblock could build this library.
> Functionalities:
>  1 create a new image.
>  2 sync access of an image.
>  3 basic image information retrieving such as backing file.
>  4 detect if a sector is allocated in an image.
> Supported Formats:
>  ALL using file protocols.
> 
>   Patch 1 to 3 prepares qemu to accept libqblock.
> 
> v2:
>   Insert reserved bytes into union.
>   Use uint64_t instead of size_t, offset.
>   Use const char * in filename pointer.
>   Initialization function removed and it was automatically executed when
> library is loaded.
>   Added compile flag visibility=hidden, to avoid name space pollution.
>   Structure naming style changed.
>   Using byte unit instead of sector for every API.
>   Added a member in image static information structure, to report logical
> sector size, which is always 512 now.
>   Read and write API can take request not aligned to 512 now. It returns the
> byte number that have succeed in operation, but now either negative value
> or the number requested would be returned, because qemu block sync I/O API
> would not return such number.
>   Typo fix due to comments and improved documents.
> 
> v3:
>   Removed the code about OOM error, introduced GError.
>   Used a table to map from string to enum types about format.
>   Use typedef for every structure.
>   Improved the gcc compiler macro to warn if gcc was not used.
>   Global variable name changed with prefix libqb_.
>   The struct QBlockStaticInfo was changed to folder full format related
> information inside, and a new member with pointers pointing to the mostly used
> members, such as backing file, virt size, was added. This would allow the user
> to get full information about how it is created in the future.
>   Each patch in the serial can work with qemu now.
>   Typo fixes.
> 
> v4:
>   Renamed QBroker to QBlockContext.
>   Removed tool objs out of libqblock.
>   Added a check in initialization about structure size for ABI.
>   Added a new helper API to duplicate protocol information, helps to open 
> files
> in a backing file chain.
>   Check-libqblock will not rebuild libqblock every time now.
>   Test case file renamed to "libqblock-[FMT].c".
>   Test use gtest framework now.
>   Test do random creation of test file now, added check for information API in
> it.
>   Test do random sync io instead of fixed offset io now.
>   Test accept one parameter about where to place the test image, now it is
> ./tests/libqblock/test_images.
> 
> v5:
>   Makefile of libqblock was adjusted to be similar as libcacard, added spec
> file and install section.
>   Removed warning when GCC was not found.
>   Structure names were changed to better ones.
>   Removed the union typedef that contain reserved bytes to reduce the folder
> depth.
>   Some format related enum options was changed to better name.
>   Added accessors about image static information, hide indirect accessing
> member detail in the structure.
>   Test Makefile do not create diretory now, test case create it themself.
>   Test build system do not use libtool now, and removed qtest-obj-y in its
> dependency, make check will automatically execute test anyway now.
>   Removed "ifeq ($(LIBTOOL),)" in Makefile.
> 
> v6:
>   Remove address pointer member in image static info structure.
> 
> v7:
>   Support out of tree building.
> 
> v8:
>   Fix a bug in out of tree building.
> 
> v9:
>   Rebase and splitted out small fix patch for qemu.
> 
> v10:
>   Rebased to upstream, adjusted libqblock build system according to Paolo's
> comments.
> 
> v11:
>   Adjusting code in patch 4 to 7, details are in the child patch's commit
> message.
> 
> v12:
>   Split a patch to add a function in stubs, other change are in patch 4 to 7
> commit messages.
> 
> v13:
>   Moved another function into stubs, added xml rule in tests/makefile, little
> changes in patch 4, 6, 7.
> 
> v14:
>   all: Rebased.
>   1/10, 2/10: automatically call subdir's clean command if subdir's Makefile
> added $SUBDIR_CLEAN_RULES, so tests/Makefile do not need to be always 
> included,
> libqblock's rule can also use it.
>   3/10: seperated patch for configure support, modified as libcacard's style.
>   4/10: modifed as libcacard's rule.
>   5/10: seperated patch, also changed a bit to be a mirror as libcacard's 
> rule.
>   8/10: use bdrv_pread/bdrv_pwrite, instead of handling the buf allignment by
> libqblock itself. Removed libqblock-aio.c because most function are in
> block-obj-y now.
>   9/10: seperated patch, use LINK instead of custom LT_LINK rule, and now
> libqblock.la is a dependence in the link rule of test program, to make
> LINK invoke libtool.
> 
> v15:
>   1/9: merged from 1/10, 2/10 of previous version, and use dependce of "clean"
> in sub Makefile instead of a intermedia variable.
>   2/9: drop $TOOLS adding in libqblock's Makefile, the rule is added in "all".
>   3/9: drop libqblock-y in Makefile.objs, directly add them in libqblock's
> Makfile.
>   6/9: use __visibility__ in special public marking macro, change macro name
> to LIBQB_DLL_PUBLIC to avoid confilict in name space, use sizeof(uint64_t)
> instead of magic number 8 in reserved member, spelling fix. Date of file was
> changed to 2013.
>   7/9: date of file was changed to 2013.
>   8/9: test rule was added to check-unit, drop correspond rule for
> check-libqblock, drop varible $LIBQBLOCK_LA.
> 
> v16:
>   7/9: remove *o_raw and correct the enum type to fix error in building.
> 
> v17:
>   Tested on Fedora 17, build pass on RH6.2, windows.
>   1/10: remove variable CHECK_CLEAN_TARGETS.
>   2/10: new added. Because libcacard share some .lo with libqblock and they
> are compiled differently with '-f visibility', so build sequence will affect
> the build result. This patch introduce macro QEMU_DLL_PULIC to hide symbols
> in all .lo file, so they can use same .lo files now, to avoid build failure.
> All symbols in libcacard.syms are marked as public.
>   3/10: only support libqblock on LINUX now, to avoid trouble on Windows. Add
> glib-thread and glib check in configure. Dependency library was set in
> configure instead of libqblock/Makefile.
>   4/10: remove variable LIBQBLOCK_CLEAN_TARGETS, removed -fvisibility flag
> because it is added in rules.mak before.
>   7/10: change name qb_fmt to qb_format, qb_loc to qb_location. Use macro
> QEMU_DLL_PUBLIC.
>   8/10: change name qb_fmt to qb_format, qb_loc to qb_location, use g_malloc0
> in qb_context_new(). Moved init code from __constructure__ function to
> qb_context_new, to avoid it get called before block layer init, related lock
> is added.
>   9/10: remove clean for check-libqblock-y, because it is added in 
> check-unit-y.
> removed unused variale LIBQBLOCK_TEST_DIR, moved exe file adding rule to next
> patch to make build success in this patch.
>   10/10: add rule for itself in this patch. Default test dir is changed to
> /tmp/libqblock_test.
> 
> v18:
>   Tested on RH6.2.
>   3/10: using probing result before instead of re-probing for libqblock.
>   4/10: add comments about the reasion to filter out one .o file in stubs.
>   7/10:
>     error handlering:
>     remove qb_error_get_errno(), return a complete string which need to
> be freed in qb_error_get_human_str().
>     API and defines:
>     remove small macros QB_FREE and G_LIBQBLOCK_ERROR, rename
> g_libqblock_error_quark() to qb_error_quark(). Add comments about
> caching. Added reserved function pointers for every public structure,
> remove related helper functions for those public structure. Remove
> QBlockContext from public header, it is associated with QBlockImage
> now. Use QBlockImage* instead of QBlockImage** in qb_image_ref().
> remove "const" for filename in QBlockLocationInfo. Return 0 on success
> for qb_read()/qb_write(). Add comments about the flag usage in qb_create().
> use uint64_t for both length and *plenth in qb_check_allocation(). Spell
> fix.
>   8/10: related change for API.
>   10/10: related change for API. In information getting case, the code
> handle the public structure's allocation itself.
> 
> v19:
>   8/10: add static const flag for libqb_formatstr_table[], use ARRAY_SIZE
> instead of NULL condition in traversal, and directly use libqb_formatstr_table
> instead of *tb in qb_formattype2str() and qb_str2formattype(). add 
> GCC_FMT_ATTR
> flag to set_context_err(), remove useless return in void functions.
>   10/10: remove useless return in void functions.
> 
> Wenchao Xia (10):
>   1 build: add command check-clean
>   2 build: hide symbols in *.lo
>   3 libqblock: build: add configure support
>   4 libqblock: build: add rule for libqblock.la
>   5 libqblock: build: add packaging support
>   6 block: export function path_has_protocol()
>   7 libqblock: libqblock API design and type defines
>   8 libqblock: libqblock API implement
>   9 libqblock: build: add rules for test case
>   10 libqblock: test: libqblock test example
> 
>  Makefile                       |    4 +-
>  block.c                        |    2 +-
>  configure                      |   50 ++
>  include/block/block.h          |    2 +
>  include/qemu/sockets.h         |    1 +
>  include/qemu/thread.h          |    6 +
>  libcacard/cac.h                |    2 +
>  libcacard/card_7816.h          |    9 +
>  libcacard/vcard.h              |   22 +
>  libcacard/vcard_emul.h         |   12 +
>  libcacard/vcard_emul_type.h    |    3 +
>  libcacard/vcardt.h             |    8 +
>  libcacard/vevent.h             |    6 +
>  libcacard/vreader.h            |   23 +
>  libqblock/Makefile             |   54 +++
>  libqblock/libqblock-error.c    |   49 ++
>  libqblock/libqblock-error.h    |   35 ++
>  libqblock/libqblock-internal.h |   62 +++
>  libqblock/libqblock-types.h    |  264 +++++++++++
>  libqblock/libqblock.c          |  983 
> ++++++++++++++++++++++++++++++++++++++++
>  libqblock/libqblock.h          |  246 ++++++++++
>  libqblock/libqblock.pc.in      |   13 +
>  rules.mak                      |    1 +
>  tests/Makefile                 |   19 +-
>  tests/check-libqblock-qcow2.c  |  388 ++++++++++++++++
>  25 files changed, 2261 insertions(+), 3 deletions(-)
>  create mode 100644 libqblock/Makefile
>  create mode 100644 libqblock/libqblock-error.c
>  create mode 100644 libqblock/libqblock-error.h
>  create mode 100644 libqblock/libqblock-internal.h
>  create mode 100644 libqblock/libqblock-types.h
>  create mode 100644 libqblock/libqblock.c
>  create mode 100644 libqblock/libqblock.h
>  create mode 100644 libqblock/libqblock.pc.in
>  create mode 100644 tests/check-libqblock-qcow2.c

I'm happier with the public headers since v18.  Thanks for the making
the changes.

Kevin: do you want to give this series a fresh pair of eyes?

Stefan