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authorXiubo Li <xiubli@redhat.com>2019-11-26 13:24:21 +0100
committerIlya Dryomov <idryomov@gmail.com>2020-01-27 16:53:39 +0100
commit4d7ace02ba5c6ef1f8eeb32a86fef7c528bd7f36 (patch)
tree3fba3723f15ecba9f21dc00492d91adec9cfdd28 /fs/ceph/mdsmap.c
parentceph: remove unnecessary assignment in ceph_pre_init_acls() (diff)
downloadlinux-4d7ace02ba5c6ef1f8eeb32a86fef7c528bd7f36.tar.xz
linux-4d7ace02ba5c6ef1f8eeb32a86fef7c528bd7f36.zip
ceph: fix mdsmap cluster available check based on laggy number
In case the max_mds > 1 in MDS cluster and there is no any standby MDS and all the max_mds MDSs are in up:active state, if one of the up:active MDSs is dead, the m->m_num_laggy in kclient will be 1. Then the mount will fail without considering other healthy MDSs. There manybe some MDSs still "in" the cluster but not in up:active state, we will ignore them. Only when all the up:active MDSs in the cluster are laggy will treat the cluster as not be available. In case decreasing the max_mds, the cluster will not stop the extra up:active MDSs immediately and there will be a latency. During it the up:active MDS number will be larger than the max_mds, so later the m_info memories will 100% be reallocated. Here will pick out the up:active MDSs as the m_num_mds and allocate the needed memories once. 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.c48
1 files changed, 27 insertions, 21 deletions
diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index 471bac335fae..7a925e025c0a 100644
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -113,6 +113,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
int err;
u8 mdsmap_v, mdsmap_cv;
u16 mdsmap_ev;
+ u32 possible_max_rank;
m = kzalloc(sizeof(*m), GFP_NOFS);
if (!m)
@@ -138,14 +139,30 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
m->m_session_autoclose = ceph_decode_32(p);
m->m_max_file_size = ceph_decode_64(p);
m->m_max_mds = ceph_decode_32(p);
- m->m_num_mds = m->m_max_mds;
+
+ /*
+ * pick out the active nodes as the m_num_mds, the m_num_mds
+ * maybe larger than m_max_mds when decreasing the max_mds in
+ * cluster side, in other case it should less than or equal
+ * to m_max_mds.
+ */
+ m->m_num_mds = n = ceph_decode_32(p);
+ m->m_num_active_mds = m->m_num_mds;
+
+ /*
+ * the possible max rank, it maybe larger than the m->m_num_mds,
+ * for example if the mds_max == 2 in the cluster, when the MDS(0)
+ * was laggy and being replaced by a new MDS, we will temporarily
+ * receive a new mds map with n_num_mds == 1 and the active MDS(1),
+ * and the mds rank >= m->m_num_mds.
+ */
+ possible_max_rank = max((u32)m->m_num_mds, m->m_max_mds);
m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
if (!m->m_info)
goto nomem;
/* pick out active nodes from mds_info (state > 0) */
- n = ceph_decode_32(p);
for (i = 0; i < n; i++) {
u64 global_id;
u32 namelen;
@@ -215,18 +232,15 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
ceph_mds_state_name(state),
laggy ? "(laggy)" : "");
- if (mds < 0 || state <= 0)
+ if (mds < 0 || mds >= possible_max_rank) {
+ pr_warn("mdsmap_decode got incorrect mds(%d)\n", mds);
continue;
+ }
- if (mds >= m->m_num_mds) {
- int new_num = max(mds + 1, m->m_num_mds * 2);
- void *new_m_info = krealloc(m->m_info,
- new_num * sizeof(*m->m_info),
- GFP_NOFS | __GFP_ZERO);
- if (!new_m_info)
- goto nomem;
- m->m_info = new_m_info;
- m->m_num_mds = new_num;
+ if (state <= 0) {
+ pr_warn("mdsmap_decode got incorrect state(%s)\n",
+ ceph_mds_state_name(state));
+ continue;
}
info = &m->m_info[mds];
@@ -247,14 +261,6 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
info->export_targets = NULL;
}
}
- if (m->m_num_mds > m->m_max_mds) {
- /* find max up mds */
- for (i = m->m_num_mds; i >= m->m_max_mds; i--) {
- if (i == 0 || m->m_info[i-1].state > 0)
- break;
- }
- m->m_num_mds = i;
- }
/* pg_pools */
ceph_decode_32_safe(p, end, n, bad);
@@ -396,7 +402,7 @@ bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m)
return false;
if (m->m_damaged)
return false;
- if (m->m_num_laggy > 0)
+ if (m->m_num_laggy == m->m_num_active_mds)
return false;
for (i = 0; i < m->m_num_mds; i++) {
if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)