tree 8f105c71b91854c68db4281f255723356e709ccd
parent 1b83bef24c6746a146d39915a18fb5425f2facb0
author Sage Weil <sage@inktank.com> 1361903949 -0800
committer Sage Weil <sage@inktank.com> 1361919786 -0800

libceph: add support for HASHPSPOOL pool flag

The legacy behavior adds the pgid seed and pool together as the input for
CRUSH.  That is problematic because each pool's PGs end up mapping to the
same OSDs: 1.5 == 2.4 == 3.3 == ...

Instead, if the HASHPSPOOL flag is set, we has the ps and pool together and
feed that into CRUSH.  This ensures that two adjacent pools will map to
an independent pseudorandom set of OSDs.

Advertise our support for this via a protocol feature flag.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>