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| author | Xiubo Li <xiubli@redhat.com> | 2019-11-11 14:51:05 +0300 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2019-11-25 13:44:02 +0300 |
| commit | 74d6f03019f8d70e7f634b8a6b1309051933d36e (patch) | |
| tree | e2e0ee79f84bc2659484e7efc8c8d2ebf11ccd82 /fs/ceph/mdsmap.c | |
| parent | 6b0a877422108372ac25b41ab651e6aa9ed273a6 (diff) | |
| download | linux-74d6f03019f8d70e7f634b8a6b1309051933d36e.tar.xz | |
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.c | 11 |
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; } |