[CRIU] [PATCH 00/11] Add support for flock&posix file locks' dump/restore

[Gu Zheng]

Hi Huang,
	Very nice work, I(Zheng Gu) have departed from Huawei, and join in
FNST(cn.fujitsu.com), my new email is <guz.fnst at cn.fujitsu.com>.

Thanks,
Zheng Gu	

On 01/17/2013 04:09 PM, Qiang Huang wrote:

> It's hard to do it perfect, because we can not guarantee that once we
> terminated the processes we've dumped and the locks would be dropped too.
> We can't deal issues like tasks beyond pstree would use flocks hold by
> dumped tasks yet.
> 
> Right now we assume that all flock users are all taken into dump, so we
> only did simple check:
> If we didn't set handle file locks option, then any file locks hold by
> tasks in our pstree is not allowed.
> 
> We might have to do the check that file locks dump/restore would only be
> used by container dumping in the future.
> 
> Anyway, thanks to the ptrace-seize machanism, the kernel will unblock
> task from flock and will stop it in another place when we ptrace-seize
> it. So we can aviod the blocked file lock problems, makes the work
> simpler.
> 
> This work is based on Zheng Gu's first attempt on:
> http://lists.openvz.org/pipermail/criu/2012-November/005646.html
> 
> Changelog since the initial version:
> a. Collect all file lock info before dump.
> b. Parse /proc/locks in proc_parse.c.
> c. Check the file lock option when some tasks hold file locks.
> d. Add zdtm test cases for file lock.
> e. Code organization optimization.
> f. Some bugfix, pr_info and comments.
> 
> Qiang Huang (11):
>   crtools: Add --file-locks option
>   protobuf: add a new description for saving file-lock
>   crtools: add a callback to show filelocks-%d.img
>   crtools: add image contents for filelocks
>   pstree: add a function to check if a task is in pstree
>   crtools: collect and check file locks
>   crtools: dump flock&posix file locks
>   crtools: restore flock&posix file locks
>   doc: update the manpage document for file lock c/r
>   zdtm: add posix file lock's test case
>   zdtm: add flock file lock's test case
> 
>  Documentation/crtools.txt            |    5 +
>  Makefile                             |    1 +
>  cr-dump.c                            |  177 +++++++++++++++++++++++++++++++++
>  cr-restore.c                         |    4 +
>  cr-show.c                            |    5 +
>  crtools.c                            |    7 +-
>  file-lock.c                          |  141 ++++++++++++++++++++++++++
>  image.c                              |    1 +
>  include/crtools.h                    |    3 +
>  include/file-lock.h                  |   53 ++++++++++
>  include/image.h                      |    1 +
>  include/proc_parse.h                 |    1 +
>  include/protobuf.h                   |    1 +
>  include/pstree.h                     |    1 +
>  proc_parse.c                         |   95 ++++++++++++++++++
>  protobuf.c                           |    2 +
>  protobuf/Makefile                    |    1 +
>  protobuf/file-lock.proto             |    8 ++
>  pstree.c                             |   12 +++
>  test/zdtm.sh                         |   12 ++-
>  test/zdtm/live/static/Makefile       |    2 +
>  test/zdtm/live/static/file_locks00.c |  179 ++++++++++++++++++++++++++++++++++
>  test/zdtm/live/static/file_locks01.c |  141 ++++++++++++++++++++++++++
>  23 files changed, 851 insertions(+), 2 deletions(-)
>  create mode 100644 file-lock.c
>  create mode 100644 include/file-lock.h
>  create mode 100644 protobuf/file-lock.proto
>  create mode 100644 test/zdtm/live/static/file_locks00.c
>  create mode 100644 test/zdtm/live/static/file_locks01.c
> 
> 
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