git: hammer2 - freemap part 4, misc fixes
dillon at crater.dragonflybsd.org
Thu Jun 13 00:19:04 PDT 2013
Author: Matthew Dillon <dillon at apollo.backplane.com>
Date: Thu Jun 13 00:11:04 2013 -0700
hammer2 - freemap part 4, misc fixes
* Revamp the freemap a bit. Remove Layer 0. Layer 1 is now the LEAF.
2GB of media storage is now represented by a single 64KB Layer 1 block.
Synchronize the FREEMAP document with the current thinking.
The Layer 1 block contains 1024x64 entries. Each entry represents 2MBytes
of media storage. These entries are no longer blockrefs pointing to
Layer 0 but are instead terminal structures.
* Each entry represents a 16KB allocation granularity in 2 bits and has
128 bit pairs (256 bits total), plus additional information to represent
the 2MBytes of storage.
Fine-grained allocations are supported via an iterator field, currently
allowing fine-grained allocations down to 1KB and potentially expandable
in the future to even smaller allocation sizes.
* Fix a SMP race in voldata handling during flush. The freemap portion of
voldata could be updated during crc calculations due to hmp->fchain not
being held locked, causing random volume header/backups to fail their CRC
test on remount.
* Add missing BUF_KERNPROC() when chain->bp is replaced. Fixes a kernel
lock ownership assertion.
* Add freezone/radix fields to the inode_data structure. Each inode can
accomodate four fields. The fields are not yet utilized. Current thinking
is to use them to optimize the bulk free-scan for freeing blocks.
Summary of changes:
sbin/hammer2/cmd_debug.c | 36 ++-
sbin/hammer2/cmd_stat.c | 2 +-
sys/vfs/hammer2/FREEMAP | 198 ++++++++----
sys/vfs/hammer2/hammer2_chain.c | 17 +-
sys/vfs/hammer2/hammer2_disk.h | 146 +++++----
sys/vfs/hammer2/hammer2_flush.c | 45 ++-
sys/vfs/hammer2/hammer2_freemap.c | 629 +++++++++++++++++---------------------
sys/vfs/hammer2/hammer2_subr.c | 8 +-
8 files changed, 581 insertions(+), 500 deletions(-)
DragonFly BSD source repository
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