From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zdenek Kabelac Date: Tue, 22 Mar 2011 22:21:54 +0100 Subject: [PATCH 0/6] VG share v2 Message-ID: List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Second version of VG sharing patch. Still rather in 'proposal' form as some part of code are not fully finished (pool-debug code is missing, usage of posix_memalign). If someone notices some weak points - let me know. Patchset add support for locking and unlocking memory pool. Such pool has volatile memory area attached. VG sharing is made in way the only 1 user could work with such VG. It may optionaly modify few small parts (only uin64_t is supported) which are reverted before next reuse. 2 methods to catch writes are implemented - mprotect - memory consuming, and creates immediate segfault when expected change of pool content happens. But it's fast and give exact location of such writer. pool_crc - simple hash crc checksum - gives notice that after multiple uses is not in its original state - doesn't segfault, but it's hard to detect such writer. And checksumming consumes some CPU. Pool volatile area uses very simle 'exception pair values' - if there would be a lot of them - more efficent code would be needed. Also support for storing more differnet types would add some complexity. Both these extension do not seem to be needed with current code. Patch set - as is - passes valgrind tests. Zdenek Kabelac (6): Pool locking code Code move vg_mark_partial up in stack Share VG multiple times Use dm_pool_set_uint64 lv_postorder using dm_pool_set_uint64 lv_postorder unlock and lock lib/activate/activate.c | 5 +- lib/cache/lvmcache.c | 111 ++++++++++++++++++- lib/cache/lvmcache.h | 3 + lib/metadata/lv.h | 5 +- lib/metadata/metadata.c | 58 ++++++++-- lib/metadata/snapshot_manip.c | 15 ++- lib/metadata/vg.h | 2 + libdm/libdevmapper.h | 11 ++ libdm/mm/pool-debug.c | 9 ++ libdm/mm/pool-fast.c | 74 ++++++++++++- libdm/mm/pool.c | 246 ++++++++++++++++++++++++++++++++++++++++- 11 files changed, 517 insertions(+), 22 deletions(-) -- 1.7.4.1