We don't need to use up entropy to choose an mds, so use prandom_u32() to get a pseudo-random number.
Also, we don't need to choose a random mds if only one mds is available, so add special casing for the common case. Fixes http://tracker.ceph.com/issues/3579 Signed-off-by: Sam Lang <[email protected]> --- fs/ceph/mdsmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c index 0d3c924..9278dec 100644 --- a/fs/ceph/mdsmap.c +++ b/fs/ceph/mdsmap.c @@ -20,7 +20,10 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) { int n = 0; int i; - char r; + + /* special case for one mds */ + if (1 == m->m_max_mds && m->m_info[0].state > 0) + return 0; /* count */ for (i = 0; i < m->m_max_mds; i++) @@ -30,8 +33,7 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m) return -1; /* pick */ - get_random_bytes(&r, 1); - n = r % n; + n = prandom_u32() % n; i = 0; for (i = 0; n > 0; i++, n--) while (m->m_info[i].state <= 0) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
