Merge tag 'tag-chrome-platform-for-v5.7' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-block.git] / fs / ceph / mdsmap.c

diff --git a/fs/ceph/mdsmap.c b/fs/ceph/mdsmap.c
index 471bac335fae6ed51b8db1f289e7ec3b94244450..889627817e52b2d0e0dc2bbcd7a59188edf7768a 100644 (file)
--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -13,30 +13,25 @@
 
 #include "super.h"
 
+#define CEPH_MDS_IS_READY(i, ignore_laggy) \
+       (m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
 
-/*
- * choose a random mds that is "up" (i.e. has a state > 0), or -1.
- */
-int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
+static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 {
        int n = 0;
        int i, j;
 
-       /* special case for one mds */
-       if (1 == m->m_num_mds && m->m_info[0].state > 0)
-               return 0;
-
        /* count */
-       for (i = 0; i < m->m_num_mds; i++)
-               if (m->m_info[i].state > 0)
+       for (i = 0; i < m->possible_max_rank; i++)
+               if (CEPH_MDS_IS_READY(i, ignore_laggy))
                        n++;
        if (n == 0)
                return -1;
 
        /* pick */
        n = prandom_u32() % n;
-       for (j = 0, i = 0; i < m->m_num_mds; i++) {
-               if (m->m_info[i].state > 0)
+       for (j = 0, i = 0; i < m->possible_max_rank; i++) {
+               if (CEPH_MDS_IS_READY(i, ignore_laggy))
                        j++;
                if (j > n)
                        break;
@@ -45,6 +40,20 @@ int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
        return i;
 }
 
+/*
+ * choose a random mds that is "up" (i.e. has a state > 0), or -1.
+ */
+int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m)
+{
+       int mds;
+
+       mds = __mdsmap_get_random_mds(m, false);
+       if (mds == m->possible_max_rank || mds == -1)
+               mds = __mdsmap_get_random_mds(m, true);
+
+       return mds == m->possible_max_rank ? -1 : mds;
+}
+
 #define __decode_and_drop_type(p, end, type, bad)              \
        do {                                                    \
                if (*p + sizeof(type) > end)                    \
@@ -138,14 +147,29 @@ 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;
 
-       m->m_info = kcalloc(m->m_num_mds, sizeof(*m->m_info), GFP_NOFS);
+       /*
+        * pick out the active nodes as the m_num_active_mds, the
+        * m_num_active_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_active_mds = n = ceph_decode_32(p);
+
+       /*
+        * the possible max rank, it maybe larger than the m_num_active_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_num_active_mds.
+        */
+       m->possible_max_rank = max(m->m_num_active_mds, m->m_max_mds);
+
+       m->m_info = kcalloc(m->possible_max_rank, 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 +239,15 @@ 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 >= m->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 +268,6 @@ 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);
@@ -296,14 +309,14 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 
                for (i = 0; i < n; i++) {
                        s32 mds = ceph_decode_32(p);
-                       if (mds >= 0 && mds < m->m_num_mds) {
+                       if (mds >= 0 && mds < m->possible_max_rank) {
                                if (m->m_info[mds].laggy)
                                        num_laggy++;
                        }
                }
                m->m_num_laggy = num_laggy;
 
-               if (n > m->m_num_mds) {
+               if (n > m->possible_max_rank) {
                        void *new_m_info = krealloc(m->m_info,
                                                    n * sizeof(*m->m_info),
                                                    GFP_NOFS | __GFP_ZERO);
@@ -311,7 +324,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
                                goto nomem;
                        m->m_info = new_m_info;
                }
-               m->m_num_mds = n;
+               m->possible_max_rank = n;
        }
 
        /* inc */
@@ -382,7 +395,7 @@ void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
 {
        int i;
 
-       for (i = 0; i < m->m_num_mds; i++)
+       for (i = 0; i < m->possible_max_rank; i++)
                kfree(m->m_info[i].export_targets);
        kfree(m->m_info);
        kfree(m->m_data_pg_pools);
@@ -396,9 +409,9 @@ 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++) {
+       for (i = 0; i < m->possible_max_rank; i++) {
                if (m->m_info[i].state == CEPH_MDS_STATE_ACTIVE)
                        nr_active++;
        }