/* * Copyright (C) 2012 Red Hat, Inc. * * This file is part of LVM2. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU Lesser General Public License v.2.1. * * You should have received a copy of the GNU Lesser General Public License * along with this program; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "lib.h" #include "toolcontext.h" #include "metadata.h" #include "device.h" #include "lvmetad.h" #include "lvmcache.h" #include "lvmetad-client.h" #include "format-text.h" // TODO for disk_locn, used as a DA representation #include "crc.h" #include "lvm-signal.h" #include "lvmlockd.h" #include "str_list.h" #include static daemon_handle _lvmetad = { .error = 0 }; static int _lvmetad_use = 0; static int _lvmetad_connected = 0; static int _lvmetad_daemon_pid = 0; static char *_lvmetad_token = NULL; static const char *_lvmetad_socket = NULL; static struct cmd_context *_lvmetad_cmd = NULL; static int64_t _lvmetad_update_timeout; static int _found_lvm1_metadata = 0; static struct volume_group *lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg); static uint64_t _monotonic_seconds(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) return 0; return ts.tv_sec; } static int _log_debug_inequality(const char *name, struct dm_config_node *a, struct dm_config_node *b) { int result = 0; int final_result = 0; if (a->v && b->v) { result = compare_value(a->v, b->v); if (result) { struct dm_config_value *av = a->v; struct dm_config_value *bv = b->v; if (!strcmp(a->key, b->key)) { if (a->v->type == DM_CFG_STRING && b->v->type == DM_CFG_STRING) log_debug_lvmetad("VG %s metadata inequality at %s / %s: %s / %s", name, a->key, b->key, av->v.str, bv->v.str); else if (a->v->type == DM_CFG_INT && b->v->type == DM_CFG_INT) log_debug_lvmetad("VG %s metadata inequality at %s / %s: " FMTi64 " / " FMTi64, name, a->key, b->key, av->v.i, bv->v.i); else log_debug_lvmetad("VG %s metadata inequality at %s / %s: type %d / type %d", name, a->key, b->key, av->type, bv->type); } else { log_debug_lvmetad("VG %s metadata inequality at %s / %s", name, a->key, b->key); } final_result = result; } } if (a->v && !b->v) { log_debug_lvmetad("VG %s metadata inequality at %s / %s", name, a->key, b->key); final_result = 1; } if (!a->v && b->v) { log_debug_lvmetad("VG %s metadata inequality at %s / %s", name, a->key, b->key); final_result = -1; } if (a->child && b->child) { result = _log_debug_inequality(name, a->child, b->child); if (result) final_result = result; } if (a->sib && b->sib) { result = _log_debug_inequality(name, a->sib, b->sib); if (result) final_result = result; } if (a->sib && !b->sib) { log_debug_lvmetad("VG %s metadata inequality at %s / %s", name, a->key, b->key); final_result = 1; } if (!a->sib && b->sib) { log_debug_lvmetad("VG %s metadata inequality at %s / %s", name, a->key, b->key); final_result = -1; } return final_result; } void lvmetad_disconnect(void) { if (_lvmetad_connected) daemon_close(_lvmetad); _lvmetad_connected = 0; _lvmetad_use = 0; _lvmetad_cmd = NULL; } int lvmetad_connect(struct cmd_context *cmd) { if (!lvmetad_socket_present()) { log_debug_lvmetad("Failed to connect to lvmetad: socket not present."); _lvmetad_connected = 0; _lvmetad_use = 0; _lvmetad_cmd = NULL; return 0; } _lvmetad_update_timeout = find_config_tree_int(cmd, global_lvmetad_update_wait_time_CFG, NULL); _lvmetad = lvmetad_open(_lvmetad_socket); if (_lvmetad.socket_fd >= 0 && !_lvmetad.error) { log_debug_lvmetad("Successfully connected to lvmetad on fd %d.", _lvmetad.socket_fd); _lvmetad_connected = 1; _lvmetad_use = 1; _lvmetad_cmd = cmd; return 1; } else { log_debug_lvmetad("Failed to connect to lvmetad: %s", strerror(_lvmetad.error)); _lvmetad_connected = 0; _lvmetad_use = 0; _lvmetad_cmd = NULL; return 0; } } int lvmetad_used(void) { return _lvmetad_use; } void lvmetad_make_unused(struct cmd_context *cmd) { lvmetad_disconnect(); if (cmd && !refresh_filters(cmd)) stack; } int lvmetad_pidfile_present(void) { const char *pidfile = getenv("LVM_LVMETAD_PIDFILE") ?: LVMETAD_PIDFILE; return !access(pidfile, F_OK); } int lvmetad_socket_present(void) { const char *socket = _lvmetad_socket ?: LVMETAD_SOCKET; int r; if ((r = access(socket, F_OK)) && errno != ENOENT) log_sys_error("access", socket); return !r; } void lvmetad_set_socket(const char *sock) { _lvmetad_socket = sock; } /* * Use a crc of the strings in the filter as the lvmetad token. */ void lvmetad_set_token(const struct dm_config_value *filter) { int ft = 0; dm_free(_lvmetad_token); while (filter && filter->type == DM_CFG_STRING) { ft = calc_crc(ft, (const uint8_t *) filter->v.str, strlen(filter->v.str)); filter = filter->next; } if (dm_asprintf(&_lvmetad_token, "filter:%u", ft) < 0) log_warn("WARNING: Failed to set lvmetad token. Out of memory?"); } void lvmetad_release_token(void) { dm_free(_lvmetad_token); _lvmetad_token = NULL; } /* * Check if lvmetad's token matches our token. The token is a hash of the * global filter used to populate lvmetad. The lvmetad token was set by the * last command to populate lvmetad, and it was set to the hash of the global * filter that command used when scanning to populate lvmetad. * * Our token is a hash of the global filter this command is using. * * If the lvmetad token is not set (or "none"), then lvmetad has not been * populated. If the lvmetad token is "update in progress", then lvmetad is * currently being populated -- this should be temporary, so wait for a while * for the current update to finish and then compare our token with the new one * (hopefully it will match). If the lvmetad token otherwise differs from * ours, then lvmetad was populated using a different global filter that we are * using. * * Return 1 if the lvmetad token matches ours. We can use it as is. * * Return 0 if the lvmetad token does not match ours (lvmetad is empty or * populated using a different global filter). The caller will repopulate * lvmetad (via lvmetad_pvscan_all_devs) before using lvmetad. * * If we time out waiting for an lvmetad update to finish, then disable this * command's use of lvmetad and return 0. */ int lvmetad_token_matches(struct cmd_context *cmd) { daemon_reply reply; const char *daemon_token; unsigned int delay_usec = 0; unsigned int wait_sec = 0; uint64_t now = 0, wait_start = 0; int ret = 1; wait_sec = (unsigned int)_lvmetad_update_timeout; retry: log_debug_lvmetad("Sending lvmetad get_global_info"); reply = daemon_send_simple(_lvmetad, "get_global_info", "token = %s", "skip", "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) { log_warn("WARNING: Not using lvmetad after send error (%d).", reply.error); goto fail; } if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) { log_warn("WARNING: Not using lvmetad after response error."); goto fail; } if (!(daemon_token = daemon_reply_str(reply, "token", NULL))) { log_warn("WARNING: Not using lvmetad with older version."); goto fail; } _lvmetad_daemon_pid = (int)daemon_reply_int(reply, "daemon_pid", 0); /* * If lvmetad is being updated by another command, then sleep and retry * until the token shows the update is done, and go on to the token * comparison. * * Between retries, sleep for a random period between 1 and 2 seconds. * Retry in this way for up to a configurable period of time. */ if (!strcmp(daemon_token, LVMETAD_TOKEN_UPDATE_IN_PROGRESS)) { if (!(now = _monotonic_seconds())) goto fail; if (!wait_start) wait_start = now; if (now - wait_start > wait_sec) { log_warn("WARNING: Not using lvmetad after %u sec lvmetad_update_wait_time.", wait_sec); goto fail; } log_warn("WARNING: lvmetad is being updated, retrying (setup) for %u more seconds.", wait_sec - (unsigned int)(now - wait_start)); /* Delay a random period between 1 and 2 seconds. */ delay_usec = 1000000 + lvm_even_rand(&_lvmetad_cmd->rand_seed, 1000000); usleep(delay_usec); daemon_reply_destroy(reply); goto retry; } /* * lvmetad is empty, not yet populated. * The caller should do a disk scan to populate lvmetad. */ if (!strcmp(daemon_token, "none")) { ret = 0; goto out; } /* * lvmetad has an unmatching token; it was last populated using * a different global filter. * The caller should do a disk scan to populate lvmetad with * our global filter. */ if (strcmp(daemon_token, _lvmetad_token)) { ret = 0; goto out; } out: daemon_reply_destroy(reply); return ret; fail: daemon_reply_destroy(reply); /* The command will not use lvmetad and will revert to scanning. */ lvmetad_make_unused(cmd); return 0; } /* * Wait up to lvmetad_update_wait_time for the lvmetad updating state to be * finished. * * Return 0 if lvmetad is not updating or there's an error and we can't tell. * Return 1 if lvmetad is updating. */ static int _lvmetad_is_updating(struct cmd_context *cmd, int do_wait) { daemon_reply reply; const char *daemon_token; unsigned int wait_sec = 0; uint64_t now = 0, wait_start = 0; int ret = 0; wait_sec = (unsigned int)_lvmetad_update_timeout; retry: log_debug_lvmetad("Sending lvmetad get_global_info"); reply = daemon_send_simple(_lvmetad, "get_global_info", "token = %s", "skip", "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) goto out; if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) goto out; if (!(daemon_token = daemon_reply_str(reply, "token", NULL))) goto out; if (!strcmp(daemon_token, LVMETAD_TOKEN_UPDATE_IN_PROGRESS)) { ret = 1; if (!do_wait) goto out; if (!(now = _monotonic_seconds())) goto out; if (!wait_start) wait_start = now; if (now - wait_start >= wait_sec) goto out; log_warn("WARNING: lvmetad is being updated, waiting for %u more seconds.", wait_sec - (unsigned int)(now - wait_start)); usleep(1000000); daemon_reply_destroy(reply); goto retry; } else { ret = 0; } out: daemon_reply_destroy(reply); return ret; } static daemon_reply _lvmetad_send(struct cmd_context *cmd, const char *id, ...) { va_list ap; daemon_reply reply = { 0 }; daemon_request req; const char *token_expected; unsigned int delay_usec; unsigned int wait_sec = 0; uint64_t now = 0, wait_start = 0; int daemon_in_update; int we_are_in_update; if (!_lvmetad_connected || !_lvmetad_use) { reply.error = ECONNRESET; return reply; } wait_sec = (unsigned int)_lvmetad_update_timeout; retry: req = daemon_request_make(id); if (!daemon_request_extend(req, "token = %s", _lvmetad_token ?: "none", "update_timeout = " FMTd64, (int64_t)wait_sec, "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL)) { reply.error = ENOMEM; return reply; } va_start(ap, id); daemon_request_extend_v(req, ap); va_end(ap); reply = daemon_send(_lvmetad, req); daemon_request_destroy(req); if (reply.error == ECONNRESET) log_warn("WARNING: lvmetad connection failed, cannot reconnect."); /* * For the "token_update" message, the result is handled entirely * by the _token_update() function, so return the reply immediately. */ if (!strcmp(id, "token_update")) return reply; /* * For other messages it may be useful to retry and resend the * message, so check for that case before returning the reply. * The reply will be checked further in lvmetad_handle_reply. */ if (reply.error) return reply; if (!strcmp(daemon_reply_str(reply, "response", ""), "token_mismatch")) { token_expected = daemon_reply_str(reply, "expected", ""); daemon_in_update = !strcmp(token_expected, LVMETAD_TOKEN_UPDATE_IN_PROGRESS); we_are_in_update = !strcmp(_lvmetad_token, LVMETAD_TOKEN_UPDATE_IN_PROGRESS); if (daemon_in_update && !we_are_in_update) { /* * Another command is updating lvmetad, and we cannot * use lvmetad until the update is finished. Retry our * request for a while; the update should finish * shortly. This should not usually happen because * this command already checked that the token is * usable in lvmetad_token_matches(), but it's possible * for another command's rescan to slip in between the * time we call lvmetad_token_matches() and the time we * get here to lvmetad_send(). */ if (!(now = _monotonic_seconds())) goto out; if (!wait_start) wait_start = now; if (!wait_sec || (now - wait_start >= wait_sec)) { log_warn("WARNING: Cannot use lvmetad after %u sec lvmetad_update_wait_time.", wait_sec); goto out; } log_warn("WARNING: lvmetad is being updated, retrying (%s) for %u more seconds.", id, wait_sec - (unsigned int)(now - wait_start)); /* Delay a random period between 1 and 2 seconds. */ delay_usec = 1000000 + lvm_even_rand(&_lvmetad_cmd->rand_seed, 1000000); usleep(delay_usec); daemon_reply_destroy(reply); goto retry; } else { /* See lvmetad_handle_reply for handling other cases. */ } } out: return reply; } /* * token_update happens when starting or ending an lvmetad update. * When starting we set the token to "update in progress". * When ending we set the token to our filter:. * * From the perspective of a command, the lvmetad state is one of: * "none" - the lvmetad cache is not populated and an update is required. * "filter:" - the command with can use the lvmetad cache. * "filter:" - the lvmetad cache must be updated to be used. * "update in progress" - a command is updating the lvmetad cache. * * . If none, the command will update (scan and populate lvmetad), * then use the cache. * * . If filter is matching, the command will use the cache. * * . If filter is unmatching, the command will update (scan and * populate lvmetad), then use the cache. * * . If update in progress, the command will wait for a while for the state * to become non-updating. If it changes, see above, if it doesn't change, * then the command either reverts to not using lvmetad, or does an update * (scan and populate lvmetad) and then uses the cache. * * A command that is explicitly intended to update the cache will always do * that (it may wait for a while first to allow a current update to complete). * A command that is not explicitly intended to update the cache may choose * to revert to scanning and not use lvmetad. * * Because two different updates from two commands can potentially overlap, * lvmetad saves the pid of the latest update to start, so it can reject messages * from preempted updates. This prevents an invalid mix of two different updates. * (The command makes use of the update_pid to print more informative messages.) * * If lvmetad detects that a command doing an update is taking too long, it will * change the token from "update in progress" to "none", which means a new update * is required, causing the next command to do an update. This effectively * cancels/preempts a slow/stuck update, and helps to automatically resolve * some failure cases. */ static int _token_update(int *replaced_update) { daemon_reply reply; const char *token_expected; const char *prev_token; int update_pid; int ending_our_update; log_debug_lvmetad("Sending lvmetad token_update %s", _lvmetad_token); reply = _lvmetad_send(NULL, "token_update", NULL); if (replaced_update) *replaced_update = 0; if (reply.error) { log_warn("WARNING: lvmetad token update error: %s", strerror(reply.error)); daemon_reply_destroy(reply); return 0; } update_pid = (int)daemon_reply_int(reply, "update_pid", 0); /* * A mismatch can only happen when this command attempts to set the * token to filter: at the end of its update, but the update has * been preempted in lvmetad by a new one (from update_pid). */ if (!strcmp(daemon_reply_str(reply, "response", ""), "token_mismatch")) { token_expected = daemon_reply_str(reply, "expected", ""); ending_our_update = strcmp(_lvmetad_token, LVMETAD_TOKEN_UPDATE_IN_PROGRESS); log_debug_lvmetad("Received token update mismatch expected \"%s\" our token \"%s\" update_pid %d our pid %d", token_expected, _lvmetad_token, update_pid, getpid()); if (ending_our_update && (update_pid != getpid())) { log_warn("WARNING: lvmetad was updated by another command (pid %d).", update_pid); } else { /* * Shouldn't happen. * If we're ending our update and our pid matches the update_pid, * then there would not be a mismatch. * If we're starting a new update, lvmetad never returns a * token mismatch. * In any case, it doesn't hurt to just return an error here. */ log_error(INTERNAL_ERROR "lvmetad token update mismatch pid %d matches our own pid %d", update_pid, getpid()); } daemon_reply_destroy(reply); return 0; } if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) { log_error("Failed response from lvmetad for token update."); daemon_reply_destroy(reply); return 0; } if ((prev_token = daemon_reply_str(reply, "prev_token", NULL))) { if (!strcmp(prev_token, LVMETAD_TOKEN_UPDATE_IN_PROGRESS)) if (replaced_update && (update_pid != getpid())) *replaced_update = 1; } daemon_reply_destroy(reply); return 1; } /* * Helper; evaluate the reply from lvmetad, check for errors, print diagnostics * and return a summary success/failure exit code. * * If found is set, *found indicates whether or not device exists, * and missing device is not treated as an error. */ static int _lvmetad_handle_reply(daemon_reply reply, const char *id, const char *object, int *found) { const char *token_expected; const char *action; int action_modifies = 0; int daemon_in_update; int we_are_in_update; int update_pid; if (!id) action = ""; else if (!strcmp(id, "pv_list")) action = "list PVs"; else if (!strcmp(id, "vg_list")) action = "list VGs"; else if (!strcmp(id, "vg_lookup")) action = "lookup VG"; else if (!strcmp(id, "pv_lookup")) action = "lookup PV"; else if (!strcmp(id, "pv_clear_all")) action = "clear info about all PVs"; else if (!strcmp(id, "vg_clear_outdated_pvs")) action = "clear the list of outdated PVs"; else if (!strcmp(id, "set_vg_info")) action = "set VG info"; else if (!strcmp(id, "vg_update")) action = "update VG"; else if (!strcmp(id, "vg_remove")) action = "remove VG"; else if (!strcmp(id, "pv_found")) { action = "update PV"; action_modifies = 1; } else if (!strcmp(id, "pv_gone")) { action = "drop PV"; action_modifies = 1; } else { log_error(INTERNAL_ERROR "Unchecked lvmetad message %s.", id); action = "action unknown"; } if (reply.error) { log_warn("WARNING: lvmetad cannot be used due to error: %s", strerror(reply.error)); goto fail; } /* * Errors related to token mismatch. */ if (!strcmp(daemon_reply_str(reply, "response", ""), "token_mismatch")) { token_expected = daemon_reply_str(reply, "expected", ""); update_pid = (int)daemon_reply_int(reply, "update_pid", 0); log_debug("lvmetad token mismatch, expected \"%s\" our token \"%s\"", token_expected, _lvmetad_token); daemon_in_update = !strcmp(token_expected, LVMETAD_TOKEN_UPDATE_IN_PROGRESS); we_are_in_update = !strcmp(_lvmetad_token, LVMETAD_TOKEN_UPDATE_IN_PROGRESS); if (daemon_in_update && we_are_in_update) { /* * When we do not match the update_pid, it means our * update was cancelled and another process is now * updating the cache. */ if (update_pid != getpid()) { log_warn("WARNING: lvmetad is being updated by another command (pid %d).", update_pid); } else { /* Shouldn't happen */ log_error(INTERNAL_ERROR "lvmetad update by pid %d matches our own pid %d", update_pid, getpid()); } /* We don't care if the action was modifying during a token update. */ action_modifies = 0; goto fail; } else if (daemon_in_update && !we_are_in_update) { /* * Another command is updating lvmetad, and we cannot * use lvmetad until the update is finished. * lvmetad_send resent this message up to the limit and * eventually gave up. The caller may choose to not * use lvmetad at this point and revert to scanning. */ log_warn("WARNING: lvmetad is being updated and cannot be used."); goto fail; } else if (!daemon_in_update && we_are_in_update) { /* * We are updating lvmetad after setting the token to * "update in progress", but lvmetad has a non-update * token and is rejecting our update messages. This * must mean that lvmetad cancelled our update (we were * probably too slow, taking longer than the timeout), * so another command completed an update and set the * token based on its filter. Here we've attempt to * continue our cache update, and find we've been * preempted, so we should just abort our failed * update. */ log_warn("WARNING: lvmetad was updated by another command."); /* We don't care if the action was modifying during a token update. */ action_modifies = 0; goto fail; } else if (!daemon_in_update && !we_are_in_update) { /* * Another command has updated the lvmetad cache, and * has done so using a different device filter from our * own, which has made the lvmetad token and our token * not match. This should not usually happen because * this command has already checked for a matching token * in lvmetad_token_matches(), but it's possible for * another command's rescan to slip in between the time * we call lvmetad_token_matches() and the time we get * here to lvmetad_send(). With a mismatched token * (different set of devices), we cannot use the lvmetad * cache. * * FIXME: it would be nice to have this command ignore * lvmetad at this point and revert to disk scanning, * but the layers above lvmetad_send are not yet able * to switch modes in the middle of processing. * * (The advantage of lvmetad_check_token is that it * can rescan to get the token in sync, or if that * fails it can make the command revert to scanning * from the start.) */ log_warn("WARNING: Cannot use lvmetad while it caches different devices."); goto fail; } } /* * Non-token-mismatch related error checking. */ /* All OK? */ if (!strcmp(daemon_reply_str(reply, "response", ""), "OK")) { if (found) *found = 1; return 1; } /* Unknown device permitted? */ if (found && !strcmp(daemon_reply_str(reply, "response", ""), "unknown")) { log_very_verbose("Request to %s %s%sin lvmetad did not find any matching object.", action, object, *object ? " " : ""); *found = 0; return 1; } /* Multiple VGs with the same name were found. */ if (found && !strcmp(daemon_reply_str(reply, "response", ""), "multiple")) { log_very_verbose("Request to %s %s%sin lvmetad found multiple matching objects.", action, object, *object ? " " : ""); if (found) *found = 2; return 1; } /* * Generic error message for error cases not specifically checked above. */ log_error("Request to %s %s%sin lvmetad gave response %s. Reason: %s", action, object, *object ? " " : "", daemon_reply_str(reply, "response", ""), daemon_reply_str(reply, "reason", "")); fail: /* * If the failed lvmetad message was updating lvmetad with new metadata * that has been changed by this command, it is important to restart * lvmetad (or at least rescan.) (An lvmetad update that is just * scanning disks to populate the cache is not a problem, so we try to * avoid printing a "corruption" warning in that case.) */ if (action_modifies) { /* * FIXME: experiment with killing the lvmetad process here, e.g. * kill(_lvmetad_daemon_pid, SIGKILL); */ log_warn("WARNING: To avoid corruption, restart lvmetad (or disable with use_lvmetad=0)."); } return 0; } static int _read_mda(struct lvmcache_info *info, struct format_type *fmt, const struct dm_config_node *cn) { struct metadata_area_ops *ops; dm_list_iterate_items(ops, &fmt->mda_ops) if (ops->mda_import_text && ops->mda_import_text(info, cn)) return 1; return 0; } static int _pv_populate_lvmcache(struct cmd_context *cmd, struct dm_config_node *cn, struct format_type *fmt, dev_t fallback) { struct device *dev; struct id pvid, vgid; char mda_id[32]; char da_id[32]; int i = 0; struct dm_config_node *mda, *da; uint64_t offset, size; struct lvmcache_info *info; const char *pvid_txt = dm_config_find_str(cn->child, "id", NULL), *vgid_txt = dm_config_find_str(cn->child, "vgid", NULL), *vgname = dm_config_find_str(cn->child, "vgname", NULL), *fmt_name = dm_config_find_str(cn->child, "format", NULL); dev_t devt = dm_config_find_int(cn->child, "device", 0); uint64_t devsize = dm_config_find_int64(cn->child, "dev_size", 0), label_sector = dm_config_find_int64(cn->child, "label_sector", 0); uint32_t ext_flags = (uint32_t) dm_config_find_int64(cn->child, "ext_flags", 0); uint32_t ext_version = (uint32_t) dm_config_find_int64(cn->child, "ext_version", 0); if (!fmt && fmt_name) fmt = get_format_by_name(cmd, fmt_name); if (!fmt) { log_error("PV %s not recognised. Is the device missing?", pvid_txt); return 0; } dev = dev_cache_get_by_devt(devt, cmd->filter); if (!dev && fallback) dev = dev_cache_get_by_devt(fallback, cmd->filter); if (!dev) { log_warn("WARNING: Device for PV %s not found or rejected by a filter.", pvid_txt); return 0; } if (!pvid_txt || !id_read_format(&pvid, pvid_txt)) { log_error("Missing or ill-formatted PVID for PV: %s.", pvid_txt); return 0; } if (vgid_txt) { if (!id_read_format(&vgid, vgid_txt)) return_0; } else /* NB uuid is short and NUL-terminated. */ (void) dm_strncpy((char*)&vgid, fmt->orphan_vg_name, sizeof(vgid)); if (!vgname) vgname = fmt->orphan_vg_name; if (!(info = lvmcache_add(fmt->labeller, (const char *)&pvid, dev, vgname, (const char *)&vgid, 0))) return_0; lvmcache_get_label(info)->sector = label_sector; lvmcache_get_label(info)->dev = dev; lvmcache_set_device_size(info, devsize); lvmcache_del_das(info); lvmcache_del_mdas(info); lvmcache_del_bas(info); do { sprintf(mda_id, "mda%d", i); mda = dm_config_find_node(cn->child, mda_id); if (mda) _read_mda(info, fmt, mda); ++i; } while (mda); i = 0; do { sprintf(da_id, "da%d", i); da = dm_config_find_node(cn->child, da_id); if (da) { if (!dm_config_get_uint64(da->child, "offset", &offset)) return_0; if (!dm_config_get_uint64(da->child, "size", &size)) return_0; lvmcache_add_da(info, offset, size); } ++i; } while (da); i = 0; do { sprintf(da_id, "ba%d", i); da = dm_config_find_node(cn->child, da_id); if (da) { if (!dm_config_get_uint64(da->child, "offset", &offset)) return_0; if (!dm_config_get_uint64(da->child, "size", &size)) return_0; lvmcache_add_ba(info, offset, size); } ++i; } while (da); lvmcache_set_ext_flags(info, ext_flags); lvmcache_set_ext_version(info, ext_version); return 1; } static int _pv_update_struct_pv(struct physical_volume *pv, struct format_instance *fid) { struct lvmcache_info *info; if ((info = lvmcache_info_from_pvid((const char *)&pv->id, pv->dev, 0))) { pv->label_sector = lvmcache_get_label(info)->sector; pv->dev = lvmcache_device(info); if (!pv->dev) pv->status |= MISSING_PV; if (!lvmcache_fid_add_mdas_pv(info, fid)) return_0; pv->fid = fid; } else pv->status |= MISSING_PV; /* probably missing */ return 1; } struct volume_group *lvmetad_vg_lookup(struct cmd_context *cmd, const char *vgname, const char *vgid) { struct volume_group *vg = NULL; struct volume_group *vg2 = NULL; daemon_reply reply; int found; char uuid[64]; struct format_instance *fid = NULL; struct format_instance_ctx fic; struct dm_config_node *top; const char *name, *diag_name; const char *fmt_name; struct format_type *fmt; struct dm_config_node *pvcn; struct pv_list *pvl; int rescan = 0; if (!lvmetad_used()) return NULL; if (vgid) { if (!id_write_format((const struct id*)vgid, uuid, sizeof(uuid))) return_NULL; } if (vgid && vgname) { log_debug_lvmetad("Asking lvmetad for VG %s %s", uuid, vgname); reply = _lvmetad_send(cmd, "vg_lookup", "uuid = %s", uuid, "name = %s", vgname, NULL); diag_name = uuid; } else if (vgid) { log_debug_lvmetad("Asking lvmetad for VG vgid %s", uuid); reply = _lvmetad_send(cmd, "vg_lookup", "uuid = %s", uuid, NULL); diag_name = uuid; } else if (vgname) { log_debug_lvmetad("Asking lvmetad for VG %s", vgname); reply = _lvmetad_send(cmd, "vg_lookup", "name = %s", vgname, NULL); diag_name = vgname; } else { log_error(INTERNAL_ERROR "VG name required (VGID not available)"); return NULL; } if (_lvmetad_handle_reply(reply, "vg_lookup", diag_name, &found) && found) { if ((found == 2) && vgname) { log_error("Multiple VGs found with the same name: %s.", vgname); log_error("See the --select option with VG UUID (vg_uuid)."); goto out; } if (!(top = dm_config_find_node(reply.cft->root, "metadata"))) { log_error(INTERNAL_ERROR "metadata config node not found."); goto out; } name = daemon_reply_str(reply, "name", NULL); /* fall back to lvm2 if we don't know better */ fmt_name = dm_config_find_str(top, "metadata/format", "lvm2"); if (!(fmt = get_format_by_name(cmd, fmt_name))) { log_error(INTERNAL_ERROR "We do not know the format (%s) reported by lvmetad.", fmt_name); goto out; } fic.type = FMT_INSTANCE_MDAS | FMT_INSTANCE_AUX_MDAS; fic.context.vg_ref.vg_name = name; fic.context.vg_ref.vg_id = vgid; if (!(fid = fmt->ops->create_instance(fmt, &fic))) goto_out; if ((pvcn = dm_config_find_node(top, "metadata/physical_volumes"))) for (pvcn = pvcn->child; pvcn; pvcn = pvcn->sib) _pv_populate_lvmcache(cmd, pvcn, fmt, 0); if ((pvcn = dm_config_find_node(top, "metadata/outdated_pvs"))) for (pvcn = pvcn->child; pvcn; pvcn = pvcn->sib) _pv_populate_lvmcache(cmd, pvcn, fmt, 0); top->key = name; if (!(vg = import_vg_from_lvmetad_config_tree(reply.cft, fid))) goto_out; /* * Read the VG from disk, ignoring the lvmetad copy in these * cases: * * 1. The host is not using lvmlockd, but is reading lockd VGs * using the --shared option. The shared option is meant to * let hosts not running lvmlockd look at lockd VGs, like the * foreign option allows hosts to look at foreign VGs. When * --foreign is used, the code forces a rescan since the local * lvmetad cache of foreign VGs is likely stale. Similarly, * for --shared, have the code reading the shared VGs below * not use the cached copy from lvmetad but to rescan the VG. * * 2. The host failed to acquire the VG lock from lvmlockd for * the lockd VG. In this case, the usual mechanisms for * updating the lvmetad copy of the VG have been missed. Since * we don't know if the cached copy is valid, assume it's not. * * 3. lvmetad has returned the "vg_invalid" flag, which is the * usual mechanism used by lvmlockd/lvmetad to cause a host to * reread a VG from disk that has been modified from another * host. */ if (is_lockd_type(vg->lock_type) && cmd->include_shared_vgs) { log_debug_lvmetad("Rescan VG %s because including shared", vgname); rescan = 1; } else if (is_lockd_type(vg->lock_type) && cmd->lockd_vg_rescan) { log_debug_lvmetad("Rescan VG %s because no lvmlockd lock is held", vgname); rescan = 1; } else if (dm_config_find_node(reply.cft->root, "vg_invalid")) { if (!is_lockd_type(vg->lock_type)) { /* Can happen if a previous command failed/crashed without updating lvmetad. */ log_warn("WARNING: Reading VG %s from disk because lvmetad metadata is invalid.", vgname); } else { /* This is normal when the VG was modified by another host. */ log_debug_lvmetad("Rescan VG %s because lvmetad returned invalid", vgname); } rescan = 1; } /* * locking may have detected a newer vg version and * invalidated the cached vg. */ if (rescan) { if (!(vg2 = lvmetad_pvscan_vg(cmd, vg))) { log_debug_lvmetad("VG %s from lvmetad not found during rescan.", vgname); fid = NULL; release_vg(vg); vg = NULL; goto out; } release_vg(vg); vg = vg2; fid = vg2->fid; } dm_list_iterate_items(pvl, &vg->pvs) { if (!_pv_update_struct_pv(pvl->pv, fid)) { vg = NULL; goto_out; /* FIXME error path */ } } dm_list_iterate_items(pvl, &vg->pvs_outdated) { if (!_pv_update_struct_pv(pvl->pv, fid)) { vg = NULL; goto_out; /* FIXME error path */ } } lvmcache_update_vg(vg, 0); vg_mark_partial_lvs(vg, 1); } out: if (!vg && fid) fid->fmt->ops->destroy_instance(fid); daemon_reply_destroy(reply); return vg; } struct _fixup_baton { int i; int find; int ignore; }; static int _fixup_ignored(struct metadata_area *mda, void *baton) { struct _fixup_baton *b = baton; if (b->i == b->find) mda_set_ignored(mda, b->ignore); b->i ++; return 1; } /* * After the VG is written to disk, but before it's committed, * lvmetad is told the new seqno. lvmetad sets the INVALID * flag on the cached VG and saves the new seqno. * * After the VG is committed on disk, the command sends the * new VG metadata, containing the new seqno. lvmetad sees * that it has the updated metadata and clears the INVALID * flag on the cached VG. * * If the command fails after committing the metadata on disk * but before sending the new metadata to lvmetad, then the * next command that asks lvmetad for the metadata will get * back the INVALID flag. That command will then read the * VG metadata from disk to use, and will send the latest * metadata from disk to lvmetad which will clear the * INVALID flag. */ int lvmetad_vg_update_pending(struct volume_group *vg) { char uuid[64] __attribute__((aligned(8))); daemon_reply reply; if (!lvmetad_used() || test_mode()) return 1; /* fake it */ if (!id_write_format(&vg->id, uuid, sizeof(uuid))) return_0; log_debug_lvmetad("Sending lvmetad pending VG %s (seqno %" PRIu32 ")", vg->name, vg->seqno); reply = _lvmetad_send(vg->cmd, "set_vg_info", "name = %s", vg->name, "uuid = %s", uuid, "version = %"PRId64, (int64_t)vg->seqno, NULL); if (!_lvmetad_handle_reply(reply, "set_vg_info", vg->name, NULL)) { daemon_reply_destroy(reply); return_0; } vg->lvmetad_update_pending = 1; daemon_reply_destroy(reply); return 1; } int lvmetad_vg_update_finish(struct volume_group *vg) { char uuid[64] __attribute__((aligned(8))); daemon_reply reply; struct dm_hash_node *n; struct metadata_area *mda; char mda_id[128], *num; struct volume_group *vgu; struct dm_config_tree *vgmeta; struct pv_list *pvl; struct lvmcache_info *info; struct _fixup_baton baton; if (!vg->lvmetad_update_pending) return 1; if (!(vg->fid->fmt->features & FMT_PRECOMMIT)) return 1; if (!lvmetad_used() || test_mode()) return 1; /* fake it */ if (!id_write_format(&vg->id, uuid, sizeof(uuid))) return_0; /* * vg->vg_committted is the state of the VG metadata when vg_commit() * was called. Since then, 'vg' may have been partially modified and * not committed. We only want to send committed metadata to lvmetad. * * lvmetad is sometimes updated in cases where the VG is not written * (no vg_committed). In those cases 'vg' has just been read from * disk, and we can send 'vg' to lvmetad. This happens when the * command finds the lvmetad cache invalid, so the VG has been read * from disk and is then sent to lvmetad. */ vgu = vg->vg_committed ? vg->vg_committed : vg; if (!(vgmeta = export_vg_to_config_tree(vgu))) { log_error("Failed to export VG to config tree."); return 0; } log_debug_lvmetad("Sending lvmetad updated VG %s (seqno %" PRIu32 ")", vg->name, vg->seqno); reply = _lvmetad_send(vg->cmd, "vg_update", "vgname = %s", vg->name, "metadata = %t", vgmeta, NULL); dm_config_destroy(vgmeta); if (!_lvmetad_handle_reply(reply, "vg_update", vg->name, NULL)) { /* * In this failure case, the VG cached in lvmetad remains in * the INVALID state (from lvmetad_vg_update_pending). * A subsequent command will see INVALID, ignore the cached * copy, read the VG from disk, and update the cached copy. */ daemon_reply_destroy(reply); return 0; } daemon_reply_destroy(reply); n = (vgu->fid && vgu->fid->metadata_areas_index) ? dm_hash_get_first(vgu->fid->metadata_areas_index) : NULL; while (n) { mda = dm_hash_get_data(vgu->fid->metadata_areas_index, n); (void) dm_strncpy(mda_id, dm_hash_get_key(vgu->fid->metadata_areas_index, n), sizeof(mda_id)); if ((num = strchr(mda_id, '_'))) { *num = 0; ++num; if ((info = lvmcache_info_from_pvid(mda_id, NULL, 0))) { memset(&baton, 0, sizeof(baton)); baton.find = atoi(num); baton.ignore = mda_is_ignored(mda); lvmcache_foreach_mda(info, _fixup_ignored, &baton); } } n = dm_hash_get_next(vgu->fid->metadata_areas_index, n); } dm_list_iterate_items(pvl, &vgu->pvs) { /* NB. the PV fmt pointer is sometimes wrong during vgconvert */ if (pvl->pv->dev && !lvmetad_pv_found(vg->cmd, &pvl->pv->id, pvl->pv->dev, vgu->fid ? vgu->fid->fmt : pvl->pv->fmt, pvl->pv->label_sector, NULL, NULL, NULL)) return 0; } vg->lvmetad_update_pending = 0; return 1; } int lvmetad_vg_remove_pending(struct volume_group *vg) { char uuid[64] __attribute__((aligned(8))); daemon_reply reply; if (!lvmetad_used() || test_mode()) return 1; /* fake it */ if (!id_write_format(&vg->id, uuid, sizeof(uuid))) return_0; /* Sending version/seqno 0 in set_vg_info will set the INVALID flag. */ log_debug_lvmetad("Sending lvmetad pending remove VG %s", vg->name); reply = _lvmetad_send(vg->cmd, "set_vg_info", "name = %s", vg->name, "uuid = %s", uuid, "version = %"PRId64, (int64_t)0, NULL); if (!_lvmetad_handle_reply(reply, "set_vg_info", vg->name, NULL)) { daemon_reply_destroy(reply); return_0; } daemon_reply_destroy(reply); return 1; } int lvmetad_vg_remove_finish(struct volume_group *vg) { char uuid[64]; daemon_reply reply; int result; if (!lvmetad_used() || test_mode()) return 1; /* just fake it */ vg->lvmetad_update_pending = 0; if (!id_write_format(&vg->id, uuid, sizeof(uuid))) return_0; log_debug_lvmetad("Telling lvmetad to remove VGID %s (%s)", uuid, vg->name); reply = _lvmetad_send(vg->cmd, "vg_remove", "uuid = %s", uuid, NULL); result = _lvmetad_handle_reply(reply, "vg_remove", vg->name, NULL); daemon_reply_destroy(reply); return result; } int lvmetad_pv_lookup(struct cmd_context *cmd, struct id pvid, int *found) { char uuid[64]; daemon_reply reply; int result = 0; struct dm_config_node *cn; if (!lvmetad_used()) return_0; if (!id_write_format(&pvid, uuid, sizeof(uuid))) return_0; log_debug_lvmetad("Asking lvmetad for PV %s", uuid); reply = _lvmetad_send(cmd, "pv_lookup", "uuid = %s", uuid, NULL); if (!_lvmetad_handle_reply(reply, "pv_lookup", "", found)) goto_out; if (found && !*found) goto out_success; if (!(cn = dm_config_find_node(reply.cft->root, "physical_volume"))) goto_out; else if (!_pv_populate_lvmcache(cmd, cn, NULL, 0)) goto_out; out_success: result = 1; out: daemon_reply_destroy(reply); return result; } int lvmetad_pv_lookup_by_dev(struct cmd_context *cmd, struct device *dev, int *found) { int result = 0; daemon_reply reply; struct dm_config_node *cn; if (!lvmetad_used()) return_0; log_debug_lvmetad("Asking lvmetad for PV on %s", dev_name(dev)); reply = _lvmetad_send(cmd, "pv_lookup", "device = %" PRId64, (int64_t) dev->dev, NULL); if (!_lvmetad_handle_reply(reply, "pv_lookup", dev_name(dev), found)) goto_out; if (found && !*found) goto out_success; cn = dm_config_find_node(reply.cft->root, "physical_volume"); if (!cn || !_pv_populate_lvmcache(cmd, cn, NULL, dev->dev)) goto_out; out_success: result = 1; out: daemon_reply_destroy(reply); return result; } int lvmetad_pv_list_to_lvmcache(struct cmd_context *cmd) { daemon_reply reply; struct dm_config_node *cn; if (!lvmetad_used()) return 1; log_debug_lvmetad("Asking lvmetad for complete list of known PVs"); reply = _lvmetad_send(cmd, "pv_list", NULL); if (!_lvmetad_handle_reply(reply, "pv_list", "", NULL)) { daemon_reply_destroy(reply); return_0; } if ((cn = dm_config_find_node(reply.cft->root, "physical_volumes"))) for (cn = cn->child; cn; cn = cn->sib) _pv_populate_lvmcache(cmd, cn, NULL, 0); daemon_reply_destroy(reply); return 1; } int lvmetad_get_vgnameids(struct cmd_context *cmd, struct dm_list *vgnameids) { struct vgnameid_list *vgnl; struct id vgid; const char *vgid_txt; const char *vg_name; daemon_reply reply; struct dm_config_node *cn; log_debug_lvmetad("Asking lvmetad for complete list of known VG ids/names"); reply = _lvmetad_send(cmd, "vg_list", NULL); if (!_lvmetad_handle_reply(reply, "vg_list", "", NULL)) { daemon_reply_destroy(reply); return_0; } if ((cn = dm_config_find_node(reply.cft->root, "volume_groups"))) { for (cn = cn->child; cn; cn = cn->sib) { vgid_txt = cn->key; if (!id_read_format(&vgid, vgid_txt)) { stack; continue; } if (!(vgnl = dm_pool_alloc(cmd->mem, sizeof(*vgnl)))) { log_error("vgnameid_list allocation failed."); return 0; } if (!(vg_name = dm_config_find_str(cn->child, "name", NULL))) { log_error("vg_list no name found."); return 0; } vgnl->vgid = dm_pool_strdup(cmd->mem, (char *)&vgid); vgnl->vg_name = dm_pool_strdup(cmd->mem, vg_name); if (!vgnl->vgid || !vgnl->vg_name) { log_error("vgnameid_list member allocation failed."); return 0; } dm_list_add(vgnameids, &vgnl->list); } } daemon_reply_destroy(reply); return 1; } int lvmetad_vg_list_to_lvmcache(struct cmd_context *cmd) { struct volume_group *tmp; struct id vgid; const char *vgid_txt; daemon_reply reply; struct dm_config_node *cn; if (!lvmetad_used()) return 1; log_debug_lvmetad("Asking lvmetad for complete list of known VGs"); reply = _lvmetad_send(cmd, "vg_list", NULL); if (!_lvmetad_handle_reply(reply, "vg_list", "", NULL)) { daemon_reply_destroy(reply); return_0; } if ((cn = dm_config_find_node(reply.cft->root, "volume_groups"))) for (cn = cn->child; cn; cn = cn->sib) { vgid_txt = cn->key; if (!id_read_format(&vgid, vgid_txt)) { stack; continue; } /* the call to lvmetad_vg_lookup will poke the VG into lvmcache */ tmp = lvmetad_vg_lookup(cmd, NULL, (const char*)&vgid); release_vg(tmp); } daemon_reply_destroy(reply); return 1; } struct _extract_dl_baton { int i; struct dm_config_tree *cft; struct dm_config_node *pre_sib; }; static int _extract_mda(struct metadata_area *mda, void *baton) { struct _extract_dl_baton *b = baton; struct dm_config_node *cn; char id[32]; if (!mda->ops->mda_export_text) /* do nothing */ return 1; (void) dm_snprintf(id, 32, "mda%d", b->i); if (!(cn = make_config_node(b->cft, id, b->cft->root, b->pre_sib))) return 0; if (!mda->ops->mda_export_text(mda, b->cft, cn)) return 0; b->i ++; b->pre_sib = cn; /* for efficiency */ return 1; } static int _extract_disk_location(const char *name, struct disk_locn *dl, void *baton) { struct _extract_dl_baton *b = baton; struct dm_config_node *cn; char id[32]; if (!dl) return 1; (void) dm_snprintf(id, 32, "%s%d", name, b->i); if (!(cn = make_config_node(b->cft, id, b->cft->root, b->pre_sib))) return 0; if (!config_make_nodes(b->cft, cn, NULL, "offset = %"PRId64, (int64_t) dl->offset, "size = %"PRId64, (int64_t) dl->size, NULL)) return 0; b->i ++; b->pre_sib = cn; /* for efficiency */ return 1; } static int _extract_da(struct disk_locn *da, void *baton) { return _extract_disk_location("da", da, baton); } static int _extract_ba(struct disk_locn *ba, void *baton) { return _extract_disk_location("ba", ba, baton); } static int _extract_mdas(struct lvmcache_info *info, struct dm_config_tree *cft, struct dm_config_node *pre_sib) { struct _extract_dl_baton baton = { .cft = cft }; if (!lvmcache_foreach_mda(info, &_extract_mda, &baton)) return 0; baton.i = 0; if (!lvmcache_foreach_da(info, &_extract_da, &baton)) return 0; baton.i = 0; if (!lvmcache_foreach_ba(info, &_extract_ba, &baton)) return 0; return 1; } int lvmetad_pv_found(struct cmd_context *cmd, const struct id *pvid, struct device *dev, const struct format_type *fmt, uint64_t label_sector, struct volume_group *vg, struct dm_list *found_vgnames, struct dm_list *changed_vgnames) { char uuid[64]; daemon_reply reply; struct lvmcache_info *info; struct dm_config_tree *pvmeta, *vgmeta; const char *status = NULL, *vgname = NULL; int64_t changed = 0; int result; if (!lvmetad_used() || test_mode()) return 1; if (!id_write_format(pvid, uuid, sizeof(uuid))) return_0; pvmeta = dm_config_create(); if (!pvmeta) return_0; info = lvmcache_info_from_pvid((const char *)pvid, dev, 0); if (!(pvmeta->root = make_config_node(pvmeta, "pv", NULL, NULL))) { dm_config_destroy(pvmeta); return_0; } /* TODO: resolve what does it actually mean 'info == NULL' * missing info is likely an INTERNAL_ERROR */ if (!config_make_nodes(pvmeta, pvmeta->root, NULL, "device = %"PRId64, (int64_t) dev->dev, "dev_size = %"PRId64, (int64_t) (info ? lvmcache_device_size(info) : 0), "format = %s", fmt->name, "label_sector = %"PRId64, (int64_t) label_sector, "id = %s", uuid, "ext_version = %"PRId64, (int64_t) (info ? lvmcache_ext_version(info) : 0), "ext_flags = %"PRId64, (int64_t) (info ? lvmcache_ext_flags(info) : 0), NULL)) { dm_config_destroy(pvmeta); return_0; } if (info) /* FIXME A more direct route would be much preferable. */ _extract_mdas(info, pvmeta, pvmeta->root); if (vg) { if (!(vgmeta = export_vg_to_config_tree(vg))) { dm_config_destroy(pvmeta); return_0; } log_debug_lvmetad("Telling lvmetad to store PV %s (%s) in VG %s", dev_name(dev), uuid, vg->name); reply = _lvmetad_send(cmd, "pv_found", "pvmeta = %t", pvmeta, "vgname = %s", vg->name, "metadata = %t", vgmeta, NULL); dm_config_destroy(vgmeta); } else { /* * There is no VG metadata stored on this PV. * It might or might not be an orphan. */ log_debug_lvmetad("Telling lvmetad to store PV %s (%s)", dev_name(dev), uuid); reply = _lvmetad_send(NULL, "pv_found", "pvmeta = %t", pvmeta, NULL); } dm_config_destroy(pvmeta); result = _lvmetad_handle_reply(reply, "pv_found", uuid, NULL); if (vg && result && (daemon_reply_int(reply, "seqno_after", -1) != vg->seqno || daemon_reply_int(reply, "seqno_after", -1) != daemon_reply_int(reply, "seqno_before", -1))) log_warn("WARNING: Inconsistent metadata found for VG %s", vg->name); if (result && found_vgnames) { status = daemon_reply_str(reply, "status", NULL); vgname = daemon_reply_str(reply, "vgname", NULL); changed = daemon_reply_int(reply, "changed", 0); } /* * If lvmetad now sees all PVs in the VG, it returned the * "complete" status string. Add this VG name to the list * of found VGs so that the caller can do autoactivation. * * If there was a problem notifying lvmetad about the new * PV, e.g. lvmetad was disabled due to a duplicate, then * no autoactivation is attempted. * * FIXME: there was a previous fixme indicating that * autoactivation might also be done for VGs with the * "partial" status. * * If the VG has "changed" by finding the PV, lvmetad returns * the "changed" flag. The names of "changed" VGs are saved * in the changed_vgnames lists, which is used during autoactivation. * If a VG is changed, then autoactivation refreshes LVs in the VG. */ if (found_vgnames && vgname && status && !strcmp(status, "complete")) { log_debug("VG %s is complete in lvmetad with dev %s.", vgname, dev_name(dev)); if (!str_list_add(cmd->mem, found_vgnames, dm_pool_strdup(cmd->mem, vgname))) log_error("str_list_add failed"); if (changed_vgnames && changed) { log_debug("VG %s is changed in lvmetad.", vgname); if (!str_list_add(cmd->mem, changed_vgnames, dm_pool_strdup(cmd->mem, vgname))) log_error("str_list_add failed"); } } daemon_reply_destroy(reply); return result; } int lvmetad_pv_gone(dev_t devno, const char *pv_name) { daemon_reply reply; int result; int found; if (!lvmetad_used() || test_mode()) return 1; /* * TODO: automatic volume deactivation takes place here *before* * all cached info is gone - call handler. Also, consider * integrating existing deactivation script that deactivates * the whole stack from top to bottom (not yet upstream). */ log_debug_lvmetad("Telling lvmetad to forget any PV on %s", pv_name); reply = _lvmetad_send(NULL, "pv_gone", "device = %" PRId64, (int64_t) devno, NULL); result = _lvmetad_handle_reply(reply, "pv_gone", pv_name, &found); /* We don't care whether or not the daemon had the PV cached. */ daemon_reply_destroy(reply); return result; } int lvmetad_pv_gone_by_dev(struct device *dev) { return lvmetad_pv_gone(dev->dev, dev_name(dev)); } /* * The following code implements pvscan --cache. */ struct _lvmetad_pvscan_baton { struct volume_group *vg; struct format_instance *fid; }; static int _lvmetad_pvscan_single(struct metadata_area *mda, void *baton) { struct _lvmetad_pvscan_baton *b = baton; struct volume_group *vg; if (mda_is_ignored(mda) || !(vg = mda->ops->vg_read(b->fid, "", mda, NULL, NULL, 1))) return 1; /* FIXME Also ensure contents match etc. */ if (!b->vg || vg->seqno > b->vg->seqno) b->vg = vg; else if (b->vg) release_vg(vg); return 1; } /* * The lock manager may detect that the vg cached in lvmetad is out of date, * due to something like an lvcreate from another host. * This is limited to changes that only affect the vg (not global state like * orphan PVs), so we only need to reread mdas on the vg's existing pvs. * But, a previous PV in the VG may have been removed since we last read * the VG, and that PV may have been reused for another VG. */ static struct volume_group *lvmetad_pvscan_vg(struct cmd_context *cmd, struct volume_group *vg) { char pvid_s[ID_LEN + 1] __attribute__((aligned(8))); char uuid[64] __attribute__((aligned(8))); struct label *label; struct volume_group *vg_ret = NULL; struct dm_config_tree *vgmeta_ret = NULL; struct dm_config_tree *vgmeta; struct pv_list *pvl, *pvl_new; struct device_list *devl, *devl_new, *devlsafe; struct dm_list pvs_scan; struct dm_list pvs_drop; struct dm_list pvs_new; struct lvmcache_info *info = NULL; struct format_instance *fid; struct format_instance_ctx fic = { .type = 0 }; struct _lvmetad_pvscan_baton baton; struct device *save_dev = NULL; uint32_t save_seqno = 0; int missing_devs = 0; int check_new_pvs = 0; int found; dm_list_init(&pvs_scan); dm_list_init(&pvs_drop); dm_list_init(&pvs_new); log_debug_lvmetad("Rescanning VG %s (seqno %u).", vg->name, vg->seqno); /* * Another host may have added a PV to the VG, and some * commands do not always populate their lvmcache with * all devs from lvmetad, so they would fail to find * the new PV when scanning the VG. So make sure this * command knows about all PVs from lvmetad. */ lvmcache_seed_infos_from_lvmetad(cmd); /* * Start with the list of PVs that we last saw in the VG. * Some may now be gone, and some new PVs may have been added. */ dm_list_iterate_items(pvl, &vg->pvs) { if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl)))) return_NULL; devl->dev = pvl->pv->dev; dm_list_add(&pvs_scan, &devl->list); } scan_more: /* * Run the equivalent of lvmetad_pvscan_single on each dev in the VG. */ dm_list_iterate_items_safe(devl, devlsafe, &pvs_scan) { if (!devl->dev) continue; log_debug_lvmetad("Rescan VG %s scanning %s.", vg->name, dev_name(devl->dev)); if (!label_read(devl->dev, &label, 0)) { /* Another host removed this PV from the VG. */ log_debug_lvmetad("Rescan VG %s found %s was removed.", vg->name, dev_name(devl->dev)); if ((info = lvmcache_info_from_pvid(devl->dev->pvid, NULL, 0))) lvmcache_del(info); dm_list_move(&pvs_drop, &devl->list); continue; } info = (struct lvmcache_info *) label->info; baton.vg = NULL; baton.fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic); if (!baton.fid) return_NULL; if (baton.fid->fmt->features & FMT_OBSOLETE) { log_debug_lvmetad("Ignoring obsolete format on PV %s in VG %s.", dev_name(devl->dev), vg->name); lvmcache_fmt(info)->ops->destroy_instance(baton.fid); dm_list_move(&pvs_drop, &devl->list); continue; } /* * Read VG metadata from this dev's mdas. */ lvmcache_foreach_mda(info, _lvmetad_pvscan_single, &baton); /* * The PV may have been removed from the VG by another host * since we last read the VG. */ if (!baton.vg) { log_debug_lvmetad("Rescan VG %s did not find %s.", vg->name, dev_name(devl->dev)); lvmcache_fmt(info)->ops->destroy_instance(baton.fid); dm_list_move(&pvs_drop, &devl->list); continue; } /* * The PV may have been removed from the VG and used for a * different VG since we last read the VG. */ if (strcmp(baton.vg->name, vg->name)) { log_debug_lvmetad("Rescan VG %s found different VG %s on PV %s.", vg->name, baton.vg->name, dev_name(devl->dev)); release_vg(baton.vg); dm_list_move(&pvs_drop, &devl->list); continue; } /* * The VG metadata read from each dev should match. Save the * metadata from the first dev, and compare it to the metadata * read from each other dev. */ if (!save_seqno) save_seqno = baton.vg->seqno; if (!(vgmeta = export_vg_to_config_tree(baton.vg))) { log_error("VG export to config tree failed"); release_vg(baton.vg); return NULL; } if (!vgmeta_ret) { vgmeta_ret = vgmeta; save_dev = devl->dev; } else { struct dm_config_node *meta1 = vgmeta_ret->root; struct dm_config_node *meta2 = vgmeta->root; struct dm_config_node *sib1 = meta1->sib; struct dm_config_node *sib2 = meta2->sib; /* * Do not compare the extraneous data that * export_vg_to_config_tree() inserts next to the * actual VG metadata. This includes creation_time * which may not match since it is generated separately * for each call to create the config tree. * * We're saving the sibling pointer and restoring it * after the compare because we're unsure if anything * later might want it. * * FIXME: make it clearer what we're doing here, e.g. * pass a parameter to export_vg_to_config_tree() * telling it to skip the extraneous data, or something. * It's very non-obvious that setting sib=NULL does that. */ meta1->sib = NULL; meta2->sib = NULL; if (compare_config(meta1, meta2)) { log_error("VG %s metadata comparison failed for device %s vs %s", vg->name, dev_name(devl->dev), save_dev ? dev_name(save_dev) : "none"); _log_debug_inequality(vg->name, vgmeta_ret->root, vgmeta->root); meta1->sib = sib1; meta2->sib = sib2; dm_config_destroy(vgmeta); dm_config_destroy(vgmeta_ret); release_vg(baton.vg); return NULL; } meta1->sib = sib1; meta2->sib = sib2; dm_config_destroy(vgmeta); } /* * Look for any new PVs in the VG metadata that were not in our * previous version of the VG. Add them to pvs_new to be * scanned in this loop just like the old PVs. */ if (!check_new_pvs) { check_new_pvs = 1; dm_list_iterate_items(pvl_new, &baton.vg->pvs) { found = 0; dm_list_iterate_items(pvl, &vg->pvs) { if (pvl_new->pv->dev != pvl->pv->dev) continue; found = 1; break; } if (found) continue; if (!pvl_new->pv->dev) { strncpy(pvid_s, (char *) &pvl_new->pv->id, sizeof(pvid_s) - 1); if (!id_write_format((const struct id *)&pvid_s, uuid, sizeof(uuid))) stack; log_error("Device not found for PV %s in VG %s", uuid, vg->name); missing_devs++; continue; } if (!(devl_new = dm_pool_zalloc(cmd->mem, sizeof(*devl_new)))) return_NULL; devl_new->dev = pvl_new->pv->dev; dm_list_add(&pvs_new, &devl_new->list); log_debug_lvmetad("Rescan VG %s found %s was added.", vg->name, dev_name(devl_new->dev)); } } release_vg(baton.vg); } /* * Do the same scanning above for any new PVs. */ if (!dm_list_empty(&pvs_new)) { dm_list_init(&pvs_scan); dm_list_splice(&pvs_scan, &pvs_new); dm_list_init(&pvs_new); log_debug_lvmetad("Rescan VG %s found new PVs to scan.", vg->name); goto scan_more; } if (missing_devs) { if (vgmeta_ret) dm_config_destroy(vgmeta_ret); return_NULL; } /* * Remove pvs_drop entries from lvmetad. */ dm_list_iterate_items(devl, &pvs_drop) { if (!devl->dev) continue; log_debug_lvmetad("Rescan VG %s dropping %s.", vg->name, dev_name(devl->dev)); if (!lvmetad_pv_gone_by_dev(devl->dev)) return_NULL; } /* * Update the VG in lvmetad. */ if (vgmeta_ret) { fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic); if (!(vg_ret = import_vg_from_config_tree(vgmeta_ret, fid))) { log_error("VG import from config tree failed"); lvmcache_fmt(info)->ops->destroy_instance(fid); goto out; } /* * Update lvmetad with the newly read version of the VG. * When the seqno is unchanged the cached VG can be left. */ if (save_seqno != vg->seqno) { dm_list_iterate_items(devl, &pvs_scan) { if (!devl->dev) continue; log_debug_lvmetad("Rescan VG %s dropping to replace %s.", vg->name, dev_name(devl->dev)); if (!lvmetad_pv_gone_by_dev(devl->dev)) return_NULL; } log_debug_lvmetad("Rescan VG %s updating lvmetad from seqno %u to seqno %u.", vg->name, vg->seqno, save_seqno); /* * If this vg_update fails the cached metadata in * lvmetad will remain invalid. */ vg_ret->lvmetad_update_pending = 1; if (!lvmetad_vg_update_finish(vg_ret)) log_error("Failed to update lvmetad with new VG meta"); } dm_config_destroy(vgmeta_ret); } out: if (vg_ret) log_debug_lvmetad("Rescan VG %s done (seqno %u).", vg_ret->name, vg_ret->seqno); return vg_ret; } int lvmetad_pvscan_single(struct cmd_context *cmd, struct device *dev, struct dm_list *found_vgnames, struct dm_list *changed_vgnames) { struct label *label; struct lvmcache_info *info; struct _lvmetad_pvscan_baton baton; /* Create a dummy instance. */ struct format_instance_ctx fic = { .type = 0 }; if (!lvmetad_used()) { log_error("Cannot proceed since lvmetad is not active."); return 0; } if (udev_dev_is_mpath_component(dev)) { log_debug("Ignore multipath component for pvscan."); return 1; } if (!label_read(dev, &label, 0)) { log_print_unless_silent("No PV label found on %s.", dev_name(dev)); if (!lvmetad_pv_gone_by_dev(dev)) goto_bad; return 1; } info = (struct lvmcache_info *) label->info; baton.vg = NULL; baton.fid = lvmcache_fmt(info)->ops->create_instance(lvmcache_fmt(info), &fic); if (!baton.fid) goto_bad; if (baton.fid->fmt->features & FMT_OBSOLETE) { lvmcache_fmt(info)->ops->destroy_instance(baton.fid); log_warn("WARNING: Disabling lvmetad cache which does not support obsolete (lvm1) metadata."); lvmetad_set_disabled(cmd, LVMETAD_DISABLE_REASON_LVM1); _found_lvm1_metadata = 1; /* * return 1 (success) so that we'll continue to populate lvmetad * instead of leaving the update incomplete. */ return 1; } lvmcache_foreach_mda(info, _lvmetad_pvscan_single, &baton); if (!baton.vg) lvmcache_fmt(info)->ops->destroy_instance(baton.fid); if (!lvmetad_pv_found(cmd, (const struct id *) &dev->pvid, dev, lvmcache_fmt(info), label->sector, baton.vg, found_vgnames, changed_vgnames)) { release_vg(baton.vg); goto_bad; } release_vg(baton.vg); return 1; bad: return 0; } /* * Update the lvmetad cache: clear the current lvmetad cache, and scan all * devs, sending all info from the devs to lvmetad. * * We want only one command to be doing this at a time. When do_wait is set, * this will first check if lvmetad is currently being updated by another * command, and if so it will delay until that update is finished, or until a * timeout, at which point it will go ahead and do the lvmetad update. * * Callers that have already checked and waited for the updating state, e.g. by * using lvmetad_token_matches(), will generaly set do_wait to 0. Callers that * have not checked for the updating state yet will generally set do_wait to 1. * * If another command doing an update failed, it left lvmetad in the "update in * progess" state, so we can't just wait until that state has cleared, but have * to go ahead after a timeout. * * The _lvmetad_is_updating check avoids most races to update lvmetad from * multiple commands (which shouldn't generally happen anway) but does not * eliminate them. If an update race happens, the second will see that the * previous token was "update in progress" when it calls _token_update(). It * will then fail, and the command calling lvmetad_pvscan_all_devs() will * generally revert disk scanning and not use lvmetad. */ int lvmetad_pvscan_all_devs(struct cmd_context *cmd, int do_wait) { struct dev_iter *iter; struct device *dev; daemon_reply reply; char *future_token; const char *reason; int was_silent; int replacing_other_update = 0; int replaced_update = 0; int retries = 0; int ret = 1; if (!lvmetad_used()) { log_error("Cannot proceed since lvmetad is not active."); return 0; } retry: /* * If another update is in progress, delay to allow it to finish, * rather than interrupting it with our own update. */ if (do_wait && _lvmetad_is_updating(cmd, 1)) { log_warn("WARNING: lvmetad update is interrupting another update in progress."); replacing_other_update = 1; } log_verbose("Scanning all devices to update lvmetad."); if (!(iter = dev_iter_create(cmd->lvmetad_filter, 1))) { log_error("dev_iter creation failed"); return 0; } future_token = _lvmetad_token; _lvmetad_token = (char *) LVMETAD_TOKEN_UPDATE_IN_PROGRESS; if (!_token_update(&replaced_update)) { log_error("Failed to update lvmetad which had an update in progress."); dev_iter_destroy(iter); _lvmetad_token = future_token; return 0; } /* * if _token_update() sets replaced_update to 1, it means that we set * "update in progress" when the lvmetad was already set to "udpate in * progress". This detects a race between two commands doing updates * at once. The attempt above to avoid this race using * _lvmetad_is_updating isn't perfect. */ if (!replacing_other_update && replaced_update) { if (do_wait && !retries) { retries = 1; log_warn("WARNING: lvmetad update in progress, retrying update."); dev_iter_destroy(iter); _lvmetad_token = future_token; goto retry; } log_warn("WARNING: lvmetad update in progress, skipping update."); dev_iter_destroy(iter); _lvmetad_token = future_token; return 0; } log_debug_lvmetad("Telling lvmetad to clear its cache"); reply = _lvmetad_send(cmd, "pv_clear_all", NULL); if (!_lvmetad_handle_reply(reply, "pv_clear_all", "", NULL)) ret = 0; daemon_reply_destroy(reply); was_silent = silent_mode(); init_silent(1); while ((dev = dev_iter_get(iter))) { if (sigint_caught()) { ret = 0; stack; break; } if (!lvmetad_pvscan_single(cmd, dev, NULL, NULL)) { ret = 0; stack; break; } } init_silent(was_silent); dev_iter_destroy(iter); _lvmetad_token = future_token; /* * If we failed to fully and successfully populate lvmetad just leave * the existing "update in progress" token in place so lvmetad will * time out our update and force another command to do it. * (We could try to set the token to empty here, but that doesn't * help much.) */ if (!ret) return 0; if (!_token_update(NULL)) { log_error("Failed to update lvmetad token after device scan."); return 0; } /* * If lvmetad is disabled, and no lvm1 metadata was seen and no * duplicate PVs were seen, then re-enable lvmetad. */ if (lvmetad_is_disabled(cmd, &reason) && !lvmcache_found_duplicate_pvs() && !_found_lvm1_metadata) { log_debug_lvmetad("Enabling lvmetad which was previously disabled."); lvmetad_clear_disabled(cmd); } return ret; } int lvmetad_vg_clear_outdated_pvs(struct volume_group *vg) { char uuid[64]; daemon_reply reply; int result; if (!id_write_format(&vg->id, uuid, sizeof(uuid))) return_0; log_debug_lvmetad("Sending lvmetad vg_clear_outdated_pvs"); reply = _lvmetad_send(vg->cmd, "vg_clear_outdated_pvs", "vgid = %s", uuid, NULL); result = _lvmetad_handle_reply(reply, "vg_clear_outdated_pvs", vg->name, NULL); daemon_reply_destroy(reply); return result; } /* * Records the state of cached PVs in lvmetad so we can look for changes * after rescanning. */ struct pv_cache_list { struct dm_list list; dev_t devt; struct id pvid; const char *vgid; unsigned found : 1; unsigned update_udev : 1; }; /* * Get the list of PVs known to lvmetad. */ static int _lvmetad_get_pv_cache_list(struct cmd_context *cmd, struct dm_list *pvc_list) { daemon_reply reply; struct dm_config_node *cn; struct pv_cache_list *pvcl; const char *pvid_txt; const char *vgid; if (!lvmetad_used()) return 1; log_debug_lvmetad("Asking lvmetad for complete list of known PVs"); reply = _lvmetad_send(cmd, "pv_list", NULL); if (!_lvmetad_handle_reply(reply, "pv_list", "", NULL)) { daemon_reply_destroy(reply); return_0; } if ((cn = dm_config_find_node(reply.cft->root, "physical_volumes"))) { for (cn = cn->child; cn; cn = cn->sib) { if (!(pvcl = dm_pool_zalloc(cmd->mem, sizeof(*pvcl)))) { log_error("pv_cache_list allocation failed."); return 0; } pvid_txt = cn->key; if (!id_read_format(&pvcl->pvid, pvid_txt)) { stack; continue; } pvcl->devt = dm_config_find_int(cn->child, "device", 0); if ((vgid = dm_config_find_str(cn->child, "vgid", NULL))) pvcl->vgid = dm_pool_strdup(cmd->mem, vgid); dm_list_add(pvc_list, &pvcl->list); } } daemon_reply_destroy(reply); return 1; } /* * Opening the device RDWR should trigger a udev db update. * FIXME: is there a better way to update the udev db than * doing an open/close of the device? - For example writing * "change" to /sys/block//uevent? */ static void _update_pv_in_udev(struct cmd_context *cmd, dev_t devt) { struct device *dev; log_debug_devs("device %d:%d open to update udev", (int)MAJOR(devt), (int)MINOR(devt)); if (!(dev = dev_cache_get_by_devt(devt, cmd->lvmetad_filter))) { log_error("_update_pv_in_udev no dev found"); return; } if (!dev_open(dev)) { stack; return; } if (!dev_close(dev)) stack; } /* * Compare before and after PV lists from before/after rescanning, * and update udev db for changes. * * For PVs that have changed pvid or vgid in lvmetad from rescanning, * there may be information in the udev database to update, so open * these devices to trigger a udev update. * * "before" refers to the list of pvs from lvmetad before rescanning * "after" refers to the list of pvs from lvmetad after rescanning * * Comparing both lists, we can see which PVs changed (pvid or vgid), * and trigger a udev db update for those. */ static void _update_changed_pvs_in_udev(struct cmd_context *cmd, struct dm_list *pvc_before, struct dm_list *pvc_after) { struct pv_cache_list *before; struct pv_cache_list *after; char id_before[ID_LEN + 1]; char id_after[ID_LEN + 1]; int found; dm_list_iterate_items(before, pvc_before) { found = 0; dm_list_iterate_items(after, pvc_after) { if (after->found) continue; if (before->devt != after->devt) continue; if (!id_equal(&before->pvid, &after->pvid)) { (void) dm_strncpy(id_before, (char *) &before->pvid, sizeof(id_before)); (void) dm_strncpy(id_after, (char *) &after->pvid, sizeof(id_after)); log_debug_devs("device %d:%d changed pvid from %s to %s", (int)MAJOR(before->devt), (int)MINOR(before->devt), id_before, id_after); before->update_udev = 1; } else if ((before->vgid && !after->vgid) || (after->vgid && !before->vgid) || (before->vgid && after->vgid && strcmp(before->vgid, after->vgid))) { log_debug_devs("device %d:%d changed vg from %s to %s", (int)MAJOR(before->devt), (int)MINOR(before->devt), before->vgid ?: "none", after->vgid ?: "none"); before->update_udev = 1; } after->found = 1; before->found = 1; found = 1; break; } if (!found) { (void) dm_strncpy(id_before, (char *) &before->pvid, sizeof(id_before)); log_debug_devs("device %d:%d pvid %s vg %s is gone", (int)MAJOR(before->devt), (int)MINOR(before->devt), id_before, before->vgid ? before->vgid : "none"); before->update_udev = 1; } } dm_list_iterate_items(before, pvc_before) { if (before->update_udev) _update_pv_in_udev(cmd, before->devt); } dm_list_iterate_items(after, pvc_after) { if (after->update_udev) _update_pv_in_udev(cmd, after->devt); } } /* * Before this command was run, some external entity may have * invalidated lvmetad's cache of global information, e.g. lvmlockd. * * The global information includes things like a new VG, a * VG that was removed, the assignment of a PV to a VG; * any change that is not isolated within a single VG. * * The external entity, like a lock manager, would invalidate * the lvmetad global cache if it detected that the global * information had been changed on disk by something other * than a local lvm command, e.g. an lvm command on another * host with access to the same devices. (How it detects * the change is specific to lock manager or other entity.) * * The effect is that metadata on disk is newer than the metadata * in the local lvmetad daemon, and the local lvmetad's cache * should be updated from disk before this command uses it. * * So, using this function, a command checks if lvmetad's global * cache is valid. If so, it does nothing. If not, it rescans * devices to update the lvmetad cache, then it notifies lvmetad * that it's cache is valid again (consistent with what's on disk.) * This command can then go ahead and use the newly refreshed metadata. * * 1. Check if the lvmetad global cache is invalid. * 2. If so, reread metadata from all devices and update the lvmetad cache. * 3. Tell lvmetad that the global cache is now valid. */ void lvmetad_validate_global_cache(struct cmd_context *cmd, int force) { struct dm_list pvc_before; /* pv_cache_list */ struct dm_list pvc_after; /* pv_cache_list */ const char *reason = NULL; daemon_reply reply; int global_invalid; dm_list_init(&pvc_before); dm_list_init(&pvc_after); if (!lvmlockd_use()) { log_error(INTERNAL_ERROR "validate global cache without lvmlockd"); return; } if (!lvmetad_used()) return; log_debug_lvmetad("Validating global lvmetad cache"); if (force) goto do_scan; log_debug_lvmetad("lvmetad validate send get_global_info"); reply = daemon_send_simple(_lvmetad, "get_global_info", "token = %s", "skip", "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) { log_error("lvmetad_validate_global_cache get_global_info error %d", reply.error); goto do_scan; } if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) { log_error("lvmetad_validate_global_cache get_global_info not ok"); goto do_scan; } global_invalid = daemon_reply_int(reply, "global_invalid", -1); daemon_reply_destroy(reply); if (!global_invalid) return; /* cache is valid */ do_scan: /* * Save the current state of pvs from lvmetad so after devices are * scanned, we can compare to the new state to see if pvs changed. */ _lvmetad_get_pv_cache_list(cmd, &pvc_before); /* * Update the local lvmetad cache so it correctly reflects any * changes made on remote hosts. (It's possible that this command * already refreshed the local lvmetad because of a token change, * but we need to do it again here since we now hold the global * lock. Another host may have changed things between the time * we rescanned for the token, and the time we acquired the global * lock.) */ if (!lvmetad_pvscan_all_devs(cmd, 1)) { log_warn("WARNING: Not using lvmetad because cache update failed."); lvmetad_make_unused(cmd); return; } if (lvmetad_is_disabled(cmd, &reason)) { log_warn("WARNING: Not using lvmetad because %s.", reason); lvmetad_make_unused(cmd); return; } /* * Clear the global_invalid flag in lvmetad. * Subsequent local commands that read global state * from lvmetad will not see global_invalid until * another host makes another global change. */ log_debug_lvmetad("lvmetad validate send set_global_info"); reply = daemon_send_simple(_lvmetad, "set_global_info", "token = %s", "skip", "global_invalid = " FMTd64, INT64_C(0), "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) log_error("lvmetad_validate_global_cache set_global_info error %d", reply.error); if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) log_error("lvmetad_validate_global_cache set_global_info not ok"); daemon_reply_destroy(reply); /* * Populate this command's lvmcache structures from lvmetad. */ lvmcache_seed_infos_from_lvmetad(cmd); /* * Update the local udev database to reflect PV changes from * other hosts. * * Compare the before and after PV lists, and if a PV's * pvid or vgid has changed, then open that device to trigger * a uevent to update the udev db. * * This has no direct benefit to lvm, but is just a best effort * attempt to keep the udev db updated and reflecting current * lvm information. * * FIXME: lvmcache_seed_infos_from_lvmetad() and _lvmetad_get_pv_cache_list() * each get pv_list from lvmetad, and they could share a single pv_list reply. */ if (!dm_list_empty(&pvc_before)) { _lvmetad_get_pv_cache_list(cmd, &pvc_after); _update_changed_pvs_in_udev(cmd, &pvc_before, &pvc_after); } log_debug_lvmetad("Validating global lvmetad cache finished"); } int lvmetad_vg_is_foreign(struct cmd_context *cmd, const char *vgname, const char *vgid) { daemon_reply reply; struct dm_config_node *top; const char *system_id = NULL; char uuid[64]; int ret; if (!id_write_format((const struct id*)vgid, uuid, sizeof(uuid))) return_0; log_debug_lvmetad("Sending lvmetad vg_clear_outdated_pvs"); reply = _lvmetad_send(cmd, "vg_lookup", "uuid = %s", uuid, "name = %s", vgname, NULL); if ((top = dm_config_find_node(reply.cft->root, "metadata"))) system_id = dm_config_find_str(top, "metadata/system_id", NULL); ret = !is_system_id_allowed(cmd, system_id); daemon_reply_destroy(reply); return ret; } /* * lvmetad has a disabled state in which it continues running, * and returns the "disabled" flag in a get_global_info query. * * Case 1 * ------ * When "normal" commands start, (those not specifically * intended to rescan devs) they begin by checking lvmetad's * token and global info: * * - If the token doesn't match (should be uncommon), the * command first rescans devices to repopulate lvmetad with * the global_filter it is using. After rescanning, the * lvmetad disabled state is set or cleared depending on * what the scan saw. * * An unmatching token occurs when: * . lvmetad was just started and has not been populated yet. * . The global_filter has been changed in lvm.conf since the * last command was run. * . The global_filter is overriden on the command line. * (There's little point in using lvmetad if global_filter * is often changed/overridden.) * * - If the token does match (common case), the command and * lvmetad are using the same global_filter and the command * does not rescan devs to repopulate lvmetad, or change the * lvmetad disabled state. * * - After the token check/sync, the command checks if the * disabled flag is set in lvmetad. If it is, the command will * not use the lvmetad cache and will revert to scanning, i.e. * it runs the same as if use_lvmetad=0. * * So, "normal" commands try to use the lvmetad cache to avoid * scanning devices. In the uncommon case when the token doesn't * match, these commands will first rescan devs to repopulate the * lvmetad cache, and then attempt to use the lvmetad cache. * In the uncommon case where lvmetad is disabled (by a previous * command), the common commands do not rescan devs to repopulate * lvmetad, but revert the equivalent of use_lvmetad=0, reading * from disk instead of the cache. * The combination of those two uncommon cases means that a command * could begin by rescanning devs because of a token mismatch, then * disable lvmetad as a result of that scan, and continue without * using lvmetad. * * Case 2 * ------ * Commands that are meant to scan devices to repopulate the * lvmetad cache, e.g. pvscan --cache, will always rescan * devices and then set/clear the disabled state according to * what they found when scanning. The global_filter is always * used when choosing which devices to scan to populate lvmetad. * The command-specific filter is never used when choosing * which devices to scan for repopulating the lvmetad cache. * * During a scan repopulating the lvmetad cache, a command looks * for PVs with lvm1 metadata, or duplicate PVs (two devices with * the same PVID). If either of those are found during the scan, * the command sets the disabled state in lvmetad. If none are * found, the command clears the disabled state in lvmetad. * (Other problems scanning may also cause the command to set the * disabled state.) * * Case 3 * ------ * The special command 'pvscan --cache ' is meant to only * scan the specified device and send info from the dev to * lvmetad. This single-dev pvscan will not detect duplicate PVs * since it only sees the one device. If lvmetad already knows * about the same PV on another device, then lvmetad will be the * first to discover that a duplicate PV exists. In this case, * lvmetad sets the disabled state for itself. * * Duplicates * ---------- * The most common reasons for duplicate PVs to exist are: * * 1. Multipath. When multipath is running, it creates a new * mpath device for the underlying "duplicate" devs. lvm has * built in, automatic filtering that will hide the duplicate * devs of the underlying mpath dev, so the duplicates will * be skipping during scanning (multipath_component_detection). * * If multipath_component_detection=0, or if multipathd is not * running, or multipath is not set up to handle a particular * set of devs, then lvm will see the multipath paths as * duplicates. lvm will choose one of them to use, consider * the other a duplicate, and disable lvmetad. multipathd * should be configured and running to resolve these duplicates, * and multipath_component_detection enabled. * * 2. Cloning by copying. One device is copied over another, e.g. * with dd. This is a more concerning case because using the * wrong device could lead to corruption. LVM will attempt to * choose the best device as the PV, but it may not always * be the right one. In this case, lvmetad is disabled. * vgimportclone should be used on the new copy to resolve the * duplicates. * * 3. Cloning by hardware. A LUN is cloned/snapshotted on * a hardware device. The description here is the same as * cloning by copying. * * 4. Creating LVM snapshots of LVs being used as PVs. * If pvcreate is run on an LV, and lvcreate is used to * create a snapshot of that LV, then the two LVs will * appear to be duplicate PVs. * * Filtering duplicates * -------------------- * * If all but one copy of a PV is added to the global_filter, * then duplicates will not be seen when scanning to populate * the lvmetad cache. Neither common commands nor scanning * commands will see the duplicates, and lvmetad will not be * disabled. * * If the global_filter is *not* used to hide duplicates, * then lvmetad will be disabled when they are scanned, but * common commands can use the command filter to hide the * duplicates and work with a selected instance of the PV. * The command will not use lvmetad in this case, but will * not see duplicate PVs itself because its command filter * is more restrictive than the global_filter and has hidden * the duplicates. */ /* * FIXME: if we fail to disable lvmetad, then other commands could * potentially use incorrect cache data from lvmetad. Should we * do something more severe if the disable messages fails, like * sending SIGKILL to the lvmetad pid? * * FIXME: log something in syslog any time we disable lvmetad? * At a minimum if we fail to disable lvmetad. */ void lvmetad_set_disabled(struct cmd_context *cmd, const char *reason) { daemon_reply reply; if (!_lvmetad_use) return; log_debug_lvmetad("Sending lvmetad disabled %s", reason); reply = daemon_send_simple(_lvmetad, "set_global_info", "token = %s", "skip", "global_disable = " FMTd64, (int64_t)1, "disable_reason = %s", reason, "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) log_error("Failed to send message to lvmetad %d", reply.error); if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) log_error("Failed response from lvmetad."); daemon_reply_destroy(reply); } void lvmetad_clear_disabled(struct cmd_context *cmd) { daemon_reply reply; if (!_lvmetad_use) return; log_debug_lvmetad("Sending lvmetad disabled 0"); reply = daemon_send_simple(_lvmetad, "set_global_info", "token = %s", "skip", "global_disable = " FMTd64, (int64_t)0, "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) log_error("Failed to send message to lvmetad %d", reply.error); if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) log_error("Failed response from lvmetad."); daemon_reply_destroy(reply); } int lvmetad_is_disabled(struct cmd_context *cmd, const char **reason) { daemon_reply reply; const char *reply_reason; int ret = 0; reply = daemon_send_simple(_lvmetad, "get_global_info", "token = %s", "skip", "pid = " FMTd64, (int64_t)getpid(), "cmd = %s", get_cmd_name(), NULL); if (reply.error) { *reason = "send error"; ret = 1; goto out; } if (strcmp(daemon_reply_str(reply, "response", ""), "OK")) { *reason = "response error"; ret = 1; goto out; } if (daemon_reply_int(reply, "global_disable", 0)) { ret = 1; reply_reason = daemon_reply_str(reply, "disable_reason", NULL); if (!reply_reason) { *reason = ""; } else if (strstr(reply_reason, LVMETAD_DISABLE_REASON_DIRECT)) { *reason = "the disable flag was set directly"; } else if (strstr(reply_reason, LVMETAD_DISABLE_REASON_REPAIR)) { *reason = "a repair command was run"; } else if (strstr(reply_reason, LVMETAD_DISABLE_REASON_LVM1)) { *reason = "LVM1 metadata was found"; } else if (strstr(reply_reason, LVMETAD_DISABLE_REASON_DUPLICATES)) { *reason = "duplicate PVs were found"; } else if (strstr(reply_reason, LVMETAD_DISABLE_REASON_VGRESTORE)) { *reason = "vgcfgrestore is restoring VG metadata"; } else { *reason = ""; } } out: daemon_reply_destroy(reply); return ret; }