On 2019/11/12 0:45, Jeff Layton wrote:
On Mon, 2019-11-11 at 06:51 -0500, xiubli@xxxxxxxxxx wrote:
From: Xiubo Li <xiubli@xxxxxxxxxx>
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 ramdon number 1, then we should get the mds index 3 as
expected, but actually we will get index 2, which the state is -1.
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
fs/ceph/mdsmap.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index ce2d00da5096..2011147f76bf 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[0].state > 0)
There is one type mistake when resolving the conflict.
if (m->m_info[0].state > 0) ---> if (m->m_info[i].state > 0)
Thanks
BRs
+ j++;
+ if (j > n)
+ break;
+ }
return i;
}
Looks good. I'll merge after some testing.
Took me a minute but the crux of the issue is that the for loop
increment gets done regardless of the outcome of the while loop test.
This looks nicer too. I don't think it's actually possible, but the
while loop _looks_ like it could walk off the end of the array.
Thanks,
