#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_warning("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; 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) { m->m_info[mds].global_id = global_id; m->m_info[mds].state = state; m->m_info[mds].addr = addr; m->m_info[mds].laggy = (laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0); m->m_info[mds].num_export_targets = num_export_targets; if (num_export_targets) { m->m_info[mds].export_targets = kcalloc(num_export_targets, sizeof(u32), GFP_NOFS); for (j = 0; j < num_export_targets; j++) m->m_info[mds].export_targets[j] = ceph_decode_32(&pexport_targets); } else { m->m_info[mds].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(-EINVAL); } 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); }