git: sbin/hammer: Add a TODO comment for hammer recover

Tomohiro Kusumi tkusumi at
Sun Nov 6 02:51:25 PST 2016

commit 30457c934d89eaffd27155a7ffba45a3504ea94e
Author: Tomohiro Kusumi <kusumi.tomohiro at>
Date:   Sun Nov 6 14:20:12 2016 +0900

    sbin/hammer: Add a TODO comment for hammer recover
    The way hammer recover simply walks through zone-2 offset from
    0 to the end of the volume is inefficient.
    Since we know most big-blocks are not for zone-8 (B-Tree zone),
    most of the time and I/O spent for testing B-Tree nodes is wasted.
    If zone-2 offset can be reverse mapped to zone-X, it no longer
    needs to always call recover_top() assuming offsets are for
    B-Tree nodes when we know it's mostly wrong.
    Reverse mapping can also avoid possible misinterpretation of
    zone-2 buffers (i.e. wrong cast to hammer_node_ondisk_t).

Summary of changes:
 sbin/hammer/cmd_recover.c | 9 +++++++++
 1 file changed, 9 insertions(+)

DragonFly BSD source repository

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