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lvm2/lib/cache/lvmetad.c
David Teigland d455300d7b lvmlockd: fix metadata validation when rescanning VG 
When rescanning a VG from disk, the metadata read from
each PV was compared as a sanity check.  The comparison
is done by exporting the vg metadata from each dev to
a config tree, and then comparing the config trees.
The function to create the config tree inserts
extraneous information along with the actual VG metadata.
This extra info includes creation_time.  The config
trees for two devs can easily be created one second
apart in which case the different creation_times would
cause the metadata comparison to fail.  The fix is to
exclude the extraneous info from the metadata comparison.
2016-09-14 10:43:33 -05:00

2894 lines
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/*
* 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 <time.h>
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:<hash>.
*
* 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:<matching_hash>" - the command with can use the lvmetad cache.
* "filter:<unmatching_hash>" - 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:<hash> 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 = "<none>";
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", "<missing>"),
daemon_reply_str(reply, "reason", "<missing>"));
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 = %d", 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:
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/<device>/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 <dev>' 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 = "<not set>";
} else if (strstr(reply_reason, LVMETAD_DISABLE_REASON_DIRECT)) {
*reason = "the disable flag was set directly";
} 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 = "<unknown>";
}
}
out:
daemon_reply_destroy(reply);
return ret;
}
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