| commit | 3148f6779fc754711b51c40131a915c9deb16741 | |
| author | Matthew Dillon <dillon@apollo.backplane.com> | |
| Mon, 26 Jan 2015 23:48:03 +0000 (26 15:48 -0800) | ||
| committer | Matthew Dillon <dillon@apollo.backplane.com> | |
| Mon, 26 Jan 2015 23:48:03 +0000 (26 15:48 -0800) | ||
| tree | bdd93717865a18ef150b6b2f2b92cda8e14ef868 | treesnapshot (tar.gz zip) |
| parent | 8ec5b2c920b2e0bb7332e15b9c3dc910b1d6284c | commitdiff |
hammer2 - Stabilize new I/O infrastructure and work on bulkfree
* Stabilize the new asynchronous hammer_io infrastructure.
* Document the new simpler bulkfree scan algorithm. The new algorithm
scans meta-data in two passes, rebuilding the freemap in kernel memory.
It then compares the map against the live media.
The first pass transitions the freemap from (11 = allocated) to
(10 = staged for deletion), the second pass transitions (10) either back
to (11) if the block is found to not actually be freeable or to (00) if
the block winds up being actually freeable.
The two pass mechanism deals with any races and allows the scan to occur
essentially unlocked,
* Start work on the bulkfree scan algorithm.
* Stabilize the new asynchronous hammer_io infrastructure.
* Document the new simpler bulkfree scan algorithm. The new algorithm
scans meta-data in two passes, rebuilding the freemap in kernel memory.
It then compares the map against the live media.
The first pass transitions the freemap from (11 = allocated) to
(10 = staged for deletion), the second pass transitions (10) either back
to (11) if the block is found to not actually be freeable or to (00) if
the block winds up being actually freeable.
The two pass mechanism deals with any races and allows the scan to occur
essentially unlocked,
* Start work on the bulkfree scan algorithm.