+enum {
+ CONFIG_READ_NRPAGES_INIT = 1 << (20 - CFS_PAGE_SHIFT),
+ CONFIG_READ_NRPAGES = 4
+};
+
+static int mgc_apply_recover_logs(struct obd_device *mgc,
+ struct config_llog_data *cld,
+ __u64 max_version,
+ void *data, int datalen, int need_swab)
+{
+ struct config_llog_instance *cfg = &cld->cld_cfg;
+ struct lustre_sb_info *lsi = s2lsi(cfg->cfg_sb);
+ struct mgs_nidtbl_entry *entry;
+ struct lustre_cfg *lcfg;
+ struct lustre_cfg_bufs bufs;
+ u64 prev_version = 0;
+ char *inst;
+ char *buf;
+ int bufsz;
+ int pos;
+ int rc = 0;
+ int off = 0;
+ ENTRY;
+
+ LASSERT(cfg->cfg_instance != NULL);
+ LASSERT(cfg->cfg_sb == cfg->cfg_instance);
+
+ OBD_ALLOC(inst, CFS_PAGE_SIZE);
+ if (inst == NULL)
+ RETURN(-ENOMEM);
+
+ if (!(lsi->lsi_flags & LSI_SERVER)) {
+ pos = sprintf(inst, "%p", cfg->cfg_instance);
+ } else {
+ LASSERT(IS_MDT(lsi->lsi_ldd));
+ pos = sprintf(inst, "MDT%04x", lsi->lsi_ldd->ldd_svindex);
+ }
+
+ ++pos;
+ buf = inst + pos;
+ bufsz = CFS_PAGE_SIZE - pos;
+
+ while (datalen > 0) {
+ int entry_len = sizeof(*entry);
+ int is_ost;
+ struct obd_device *obd;
+ char *obdname;
+ char *cname;
+ char *params;
+ char *uuid;
+
+ rc = -EINVAL;
+ if (datalen < sizeof(*entry))
+ break;
+
+ entry = (typeof(entry))(data + off);
+
+ /* sanity check */
+ if (entry->mne_nid_type != 0) /* only support type 0 for ipv4 */
+ break;
+ if (entry->mne_nid_count == 0) /* at least one nid entry */
+ break;
+ if (entry->mne_nid_size != sizeof(lnet_nid_t))
+ break;
+
+ entry_len += entry->mne_nid_count * entry->mne_nid_size;
+ if (datalen < entry_len) /* must have entry_len at least */
+ break;
+
+ if (need_swab)
+ lustre_swab_mgs_nidtbl_entry(entry);
+ LASSERT(entry->mne_length <= CFS_PAGE_SIZE);
+ if (entry->mne_length < entry_len)
+ break;
+
+ off += entry->mne_length;
+ datalen -= entry->mne_length;
+ if (datalen < 0)
+ break;
+
+ if (entry->mne_version > max_version) {
+ CERROR("entry index(%lld) is over max_index(%lld)\n",
+ entry->mne_version, max_version);
+ break;
+ }
+
+ if (prev_version >= entry->mne_version) {
+ CERROR("index unsorted, prev %lld, now %lld\n",
+ prev_version, entry->mne_version);
+ break;
+ }
+ prev_version = entry->mne_version;
+
+ /*
+ * Write a string with format "nid::instance" to
+ * lustre/<osc|mdc>/<target>-<osc|mdc>-<instance>/import.
+ */
+
+ is_ost = entry->mne_type == LDD_F_SV_TYPE_OST;
+ memset(buf, 0, bufsz);
+ obdname = buf;
+ pos = 0;
+
+ /* lustre-OST0001-osc-<instance #> */
+ strcpy(obdname, cld->cld_logname);
+ cname = strrchr(obdname, '-');
+ if (cname == NULL) {
+ CERROR("mgc %s: invalid logname %s\n",
+ mgc->obd_name, obdname);
+ break;
+ }
+
+ pos = cname - obdname;
+ obdname[pos] = 0;
+ pos += sprintf(obdname + pos, "-%s%04x",
+ is_ost ? "OST" : "MDT", entry->mne_index);
+
+ cname = is_ost ? "osc" : "mdc",
+ pos += sprintf(obdname + pos, "-%s-%s", cname, inst);
+ lustre_cfg_bufs_reset(&bufs, obdname);
+
+ /* find the obd by obdname */
+ obd = class_name2obd(obdname);
+ if (obd == NULL) {
+ CDEBUG(D_INFO, "mgc %s: cannot find obdname %s\n",
+ mgc->obd_name, obdname);
+
+ /* this is a safe race, when the ost is starting up...*/
+ continue;
+ }
+
+ /* osc.import = "connection=<Conn UUID>::<target instance>" */
+ ++pos;
+ params = buf + pos;
+ pos += sprintf(params, "%s.import=%s", cname, "connection=");
+ uuid = buf + pos;
+
+ /* TODO: iterate all nids to find one */
+ /* find uuid by nid */
+ rc = client_import_find_conn(obd->u.cli.cl_import,
+ entry->u.nids[0],
+ (struct obd_uuid *)uuid);
+ if (rc < 0) {
+ CERROR("mgc: cannot find uuid by nid %s\n",
+ libcfs_nid2str(entry->u.nids[0]));
+ break;
+ }
+
+ CDEBUG(D_INFO, "Find uuid %s by nid %s\n",
+ uuid, libcfs_nid2str(entry->u.nids[0]));
+
+ pos += strlen(uuid);
+ pos += sprintf(buf + pos, "::%u", entry->mne_instance);
+ LASSERT(pos < bufsz);
+
+ lustre_cfg_bufs_set_string(&bufs, 1, params);
+
+ rc = -ENOMEM;
+ lcfg = lustre_cfg_new(LCFG_PARAM, &bufs);
+ if (lcfg == NULL) {
+ CERROR("mgc: cannot allocate memory\n");
+ break;
+ }
+
+ CDEBUG(D_INFO, "ir apply logs "LPD64"/"LPD64" for %s -> %s\n",
+ prev_version, max_version, obdname, params);
+
+ rc = class_process_config(lcfg);
+ lustre_cfg_free(lcfg);
+ if (rc)
+ CDEBUG(D_INFO, "process config for %s error %d\n",
+ obdname, rc);
+
+ /* continue, even one with error */
+ }
+
+ OBD_FREE(inst, CFS_PAGE_SIZE);
+ RETURN(rc);
+}
+
+/**
+ * This function is called if this client was notified for target restarting
+ * by the MGS. A CONFIG_READ RPC is going to send to fetch recovery logs.
+ */
+static int mgc_process_recover_log(struct obd_device *obd,
+ struct config_llog_data *cld)
+{
+ struct ptlrpc_request *req = NULL;
+ struct config_llog_instance *cfg = &cld->cld_cfg;
+ struct mgs_config_body *body;
+ struct mgs_config_res *res;
+ struct ptlrpc_bulk_desc *desc;
+ cfs_page_t **pages;
+ int nrpages;
+ bool eof = true;
+ int i;
+ int ealen;
+ int rc;
+ ENTRY;
+
+ /* allocate buffer for bulk transfer.
+ * if this is the first time for this mgs to read logs,
+ * CONFIG_READ_NRPAGES_INIT will be used since it will read all logs
+ * once; otherwise, it only reads increment of logs, this should be
+ * small and CONFIG_READ_NRPAGES will be used.
+ */
+ nrpages = CONFIG_READ_NRPAGES;
+ if (cfg->cfg_last_idx == 0) /* the first time */
+ nrpages = CONFIG_READ_NRPAGES_INIT;
+
+ OBD_ALLOC(pages, sizeof(*pages) * nrpages);
+ if (pages == NULL)
+ GOTO(out, rc = -ENOMEM);
+
+ for (i = 0; i < nrpages; i++) {
+ pages[i] = cfs_alloc_page(CFS_ALLOC_STD);
+ if (pages[i] == NULL)
+ GOTO(out, rc = -ENOMEM);
+ }
+
+again:
+ LASSERT(cld_is_recover(cld));
+ LASSERT(cfs_mutex_is_locked(&cld->cld_lock));
+ req = ptlrpc_request_alloc(class_exp2cliimp(cld->cld_mgcexp),
+ &RQF_MGS_CONFIG_READ);
+ if (req == NULL)
+ GOTO(out, rc = -ENOMEM);
+
+ rc = ptlrpc_request_pack(req, LUSTRE_MGS_VERSION, MGS_CONFIG_READ);
+ if (rc)
+ GOTO(out, rc);
+
+ /* pack request */
+ body = req_capsule_client_get(&req->rq_pill, &RMF_MGS_CONFIG_BODY);
+ LASSERT(body != NULL);
+ LASSERT(sizeof(body->mcb_name) > strlen(cld->cld_logname));
+ strncpy(body->mcb_name, cld->cld_logname, sizeof(body->mcb_name));
+ body->mcb_offset = cfg->cfg_last_idx + 1;
+ body->mcb_type = cld->cld_type;
+ body->mcb_bits = CFS_PAGE_SHIFT;
+ body->mcb_units = nrpages;
+
+ /* allocate bulk transfer descriptor */
+ desc = ptlrpc_prep_bulk_imp(req, nrpages, BULK_PUT_SINK,
+ MGS_BULK_PORTAL);
+ if (desc == NULL)
+ GOTO(out, rc = -ENOMEM);
+
+ for (i = 0; i < nrpages; i++)
+ ptlrpc_prep_bulk_page(desc, pages[i], 0, CFS_PAGE_SIZE);
+
+ ptlrpc_request_set_replen(req);
+ rc = ptlrpc_queue_wait(req);
+ if (rc)
+ GOTO(out, rc);
+
+ res = req_capsule_server_get(&req->rq_pill, &RMF_MGS_CONFIG_RES);
+ if (res->mcr_size < res->mcr_offset)
+ GOTO(out, rc = -EINVAL);
+
+ /* always update the index even though it might have errors with
+ * handling the recover logs */
+ cfg->cfg_last_idx = res->mcr_offset;
+ eof = res->mcr_offset == res->mcr_size;
+
+ CDEBUG(D_INFO, "Latest version "LPD64", more %d.\n",
+ res->mcr_offset, eof == false);
+
+ ealen = sptlrpc_cli_unwrap_bulk_read(req, req->rq_bulk, 0);
+ if (ealen < 0)
+ GOTO(out, rc = ealen);
+
+ if (ealen > nrpages << CFS_PAGE_SHIFT)
+ GOTO(out, rc = -EINVAL);
+
+ if (ealen == 0) { /* no logs transferred */
+ if (!eof)
+ rc = -EINVAL;
+ GOTO(out, rc);
+ }
+
+ for (i = 0; i < nrpages && ealen > 0; i++) {
+ int rc2;
+ void *ptr;
+
+ ptr = cfs_kmap(pages[i]);
+ rc2 = mgc_apply_recover_logs(obd, cld, res->mcr_offset, ptr,
+ min_t(int, ealen, CFS_PAGE_SIZE),
+ ptlrpc_rep_need_swab(req));
+ cfs_kunmap(pages[i]);
+ if (rc2 < 0) {
+ CWARN("Process recover log %s error %d\n",
+ cld->cld_logname, rc2);
+ break;
+ }
+
+ ealen -= CFS_PAGE_SIZE;
+ }
+
+out:
+ if (req)
+ ptlrpc_req_finished(req);
+
+ if (rc == 0 && !eof)
+ goto again;
+
+ if (pages) {
+ for (i = 0; i < nrpages; i++) {
+ if (pages[i] == NULL)
+ break;
+ cfs_free_page(pages[i]);
+ }
+ OBD_FREE(pages, sizeof(*pages) * nrpages);
+ }
+ return rc;
+}
+