--- /dev/null
+#include <linux/ceph/ceph_debug.h>
+
+#include <linux/bug.h>
+#include <linux/err.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <linux/ceph/mdsmap.h>
+#include <linux/ceph/messenger.h>
+#include <linux/ceph/decode.h>
+
+#include "super.h"
+
+
+/*
+ * 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 n = 0;
+ int i;
+
+ /* special case for one mds */
+ if (1 == m->m_max_mds && m->m_info[0].state > 0)
+ return 0;
+
+ /* count */
+ for (i = 0; i < m->m_max_mds; i++)
+ if (m->m_info[i].state > 0)
+ n++;
+ if (n == 0)
+ return -1;
+
+ /* pick */
+ n = prandom_u32() % n;
+ i = 0;
+ for (i = 0; n > 0; i++, n--)
+ while (m->m_info[i].state <= 0)
+ i++;
+
+ return i;
+}
+
+/*
+ * Decode an MDS map
+ *
+ * Ignore any fields we don't care about (there are quite a few of
+ * them).
+ */
+struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
+{
+ struct ceph_mdsmap *m;
+ const void *start = *p;
+ int i, j, n;
+ int err = -EINVAL;
+ u16 version;
+
+ m = kzalloc(sizeof(*m), GFP_NOFS);
+ if (m == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ ceph_decode_16_safe(p, end, version, bad);
+ if (version > 3) {
+ pr_warn("got mdsmap version %d > 3, failing", version);
+ goto bad;
+ }
+
+ ceph_decode_need(p, end, 8*sizeof(u32) + sizeof(u64), bad);
+ m->m_epoch = ceph_decode_32(p);
+ m->m_client_epoch = ceph_decode_32(p);
+ m->m_last_failure = ceph_decode_32(p);
+ m->m_root = ceph_decode_32(p);
+ m->m_session_timeout = ceph_decode_32(p);
+ 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_info = kcalloc(m->m_max_mds, sizeof(*m->m_info), GFP_NOFS);
+ if (m->m_info == NULL)
+ goto badmem;
+
+ /* 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;
+ s32 mds, inc, state;
+ u64 state_seq;
+ u8 infoversion;
+ struct ceph_entity_addr addr;
+ u32 num_export_targets;
+ void *pexport_targets = NULL;
+ struct ceph_timespec laggy_since;
+ struct ceph_mds_info *info;
+
+ ceph_decode_need(p, end, sizeof(u64)*2 + 1 + sizeof(u32), bad);
+ global_id = ceph_decode_64(p);
+ infoversion = ceph_decode_8(p);
+ *p += sizeof(u64);
+ namelen = ceph_decode_32(p); /* skip mds name */
+ *p += namelen;
+
+ ceph_decode_need(p, end,
+ 4*sizeof(u32) + sizeof(u64) +
+ sizeof(addr) + sizeof(struct ceph_timespec),
+ bad);
+ mds = ceph_decode_32(p);
+ inc = ceph_decode_32(p);
+ state = ceph_decode_32(p);
+ state_seq = ceph_decode_64(p);
+ ceph_decode_copy(p, &addr, sizeof(addr));
+ ceph_decode_addr(&addr);
+ ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
+ *p += sizeof(u32);
+ ceph_decode_32_safe(p, end, namelen, bad);
+ *p += namelen;
+ if (infoversion >= 2) {
+ ceph_decode_32_safe(p, end, num_export_targets, bad);
+ pexport_targets = *p;
+ *p += num_export_targets * sizeof(u32);
+ } else {
+ num_export_targets = 0;
+ }
+
+ dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
+ i+1, n, global_id, mds, inc,
+ ceph_pr_addr(&addr.in_addr),
+ ceph_mds_state_name(state));
+
+ if (mds < 0 || mds >= m->m_max_mds || state <= 0)
+ continue;
+
+ info = &m->m_info[mds];
+ info->global_id = global_id;
+ info->state = state;
+ info->addr = addr;
+ info->laggy = (laggy_since.tv_sec != 0 ||
+ laggy_since.tv_nsec != 0);
+ info->num_export_targets = num_export_targets;
+ if (num_export_targets) {
+ info->export_targets = kcalloc(num_export_targets,
+ sizeof(u32), GFP_NOFS);
+ if (info->export_targets == NULL)
+ goto badmem;
+ for (j = 0; j < num_export_targets; j++)
+ info->export_targets[j] =
+ ceph_decode_32(&pexport_targets);
+ } else {
+ info->export_targets = NULL;
+ }
+ }
+
+ /* pg_pools */
+ ceph_decode_32_safe(p, end, n, bad);
+ m->m_num_data_pg_pools = n;
+ m->m_data_pg_pools = kcalloc(n, sizeof(u64), GFP_NOFS);
+ if (!m->m_data_pg_pools)
+ goto badmem;
+ ceph_decode_need(p, end, sizeof(u64)*(n+1), bad);
+ for (i = 0; i < n; i++)
+ m->m_data_pg_pools[i] = ceph_decode_64(p);
+ m->m_cas_pg_pool = ceph_decode_64(p);
+
+ /* ok, we don't care about the rest. */
+ dout("mdsmap_decode success epoch %u\n", m->m_epoch);
+ return m;
+
+badmem:
+ err = -ENOMEM;
+bad:
+ pr_err("corrupt mdsmap\n");
+ print_hex_dump(KERN_DEBUG, "mdsmap: ",
+ DUMP_PREFIX_OFFSET, 16, 1,
+ start, end - start, true);
+ ceph_mdsmap_destroy(m);
+ return ERR_PTR(err);
+}
+
+void ceph_mdsmap_destroy(struct ceph_mdsmap *m)
+{
+ int i;
+
+ for (i = 0; i < m->m_max_mds; i++)
+ kfree(m->m_info[i].export_targets);
+ kfree(m->m_info);
+ kfree(m->m_data_pg_pools);
+ kfree(m);
+}
Code Review / kvmfornfv.git / blobdiff