summaryrefslogtreecommitdiffstats
path: root/fs/ceph/mdsmap.c
diff options
context:
space:
mode:
authorXiubo Li <xiubli@redhat.com>2019-11-11 12:51:05 +0100
committerIlya Dryomov <idryomov@gmail.com>2019-11-25 11:44:02 +0100
commit74d6f03019f8d70e7f634b8a6b1309051933d36e (patch)
treee2e0ee79f84bc2659484e7efc8c8d2ebf11ccd82 /fs/ceph/mdsmap.c
parentrbd: fix spelling mistake "requeueing" -> "requeuing" (diff)
downloadlinux-74d6f03019f8d70e7f634b8a6b1309051933d36e.tar.xz
linux-74d6f03019f8d70e7f634b8a6b1309051933d36e.zip
ceph: fix geting random mds from mdsmap
For example, if we have 5 mds in the mdsmap and the states are: m_info[5] --> [-1, 1, -1, 1, 1] If we get a random number 1, then we should get the mds index 3 as expected, but actually we will get index 2, which the state is -1. The issue is that the for loop increment will advance past any "up" MDS that was found during the while loop search. Signed-off-by: Xiubo Li <xiubli@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs/ceph/mdsmap.c')
-rw-r--r--fs/ceph/mdsmap.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index ce2d00da5096..aeec1d6e3769 100644
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -20,7 +20,7 @@
int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
{
int n = 0;
- int i;
+ int i, j;
/* special case for one mds */
if (1 == m->m_num_mds && m->m_info[0].state > 0)
@@ -35,9 +35,12 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
/* pick */
n = prandom_u32() % n;
- for (i = 0; n > 0; i++, n--)
- while (m->m_info[i].state <= 0)
- i++;
+ for (j = 0, i = 0; i < m->m_num_mds; i++) {
+ if (m->m_info[i].state > 0)
+ j++;
+ if (j > n)
+ break;
+ }
return i;
}