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samba-mirror/ctdb/server/ctdb_recover.c
Andrew Tridgell 9559249e15 ensure the main daemon doesn't use a blocking lock on the freelist
(This used to be ctdb commit 73f8257906b09e6516f675883d8e7a3c455ad869)
2008-01-08 22:31:48 +11:00

742 lines
20 KiB
C

/*
ctdb recovery code
Copyright (C) Andrew Tridgell 2007
Copyright (C) Ronnie Sahlberg 2007
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "lib/events/events.h"
#include "lib/tdb/include/tdb.h"
#include "system/network.h"
#include "system/filesys.h"
#include "system/wait.h"
#include "../include/ctdb_private.h"
#include "lib/util/dlinklist.h"
#include "db_wrap.h"
/*
lock all databases - mark only
*/
static int ctdb_lock_all_databases_mark(struct ctdb_context *ctdb)
{
struct ctdb_db_context *ctdb_db;
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("Attempt to mark all databases locked when not frozen\n"));
return -1;
}
for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
if (tdb_lockall_mark(ctdb_db->ltdb->tdb) != 0) {
return -1;
}
}
return 0;
}
/*
lock all databases - unmark only
*/
static int ctdb_lock_all_databases_unmark(struct ctdb_context *ctdb)
{
struct ctdb_db_context *ctdb_db;
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("Attempt to unmark all databases locked when not frozen\n"));
return -1;
}
for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
if (tdb_lockall_unmark(ctdb_db->ltdb->tdb) != 0) {
return -1;
}
}
return 0;
}
int
ctdb_control_getvnnmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
CHECK_CONTROL_DATA_SIZE(0);
struct ctdb_vnn_map_wire *map;
size_t len;
len = offsetof(struct ctdb_vnn_map_wire, map) + sizeof(uint32_t)*ctdb->vnn_map->size;
map = talloc_size(outdata, len);
CTDB_NO_MEMORY_VOID(ctdb, map);
map->generation = ctdb->vnn_map->generation;
map->size = ctdb->vnn_map->size;
memcpy(map->map, ctdb->vnn_map->map, sizeof(uint32_t)*map->size);
outdata->dsize = len;
outdata->dptr = (uint8_t *)map;
return 0;
}
int
ctdb_control_setvnnmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
struct ctdb_vnn_map_wire *map = (struct ctdb_vnn_map_wire *)indata.dptr;
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("Attempt to set vnnmap when not frozen\n"));
return -1;
}
talloc_free(ctdb->vnn_map);
ctdb->vnn_map = talloc(ctdb, struct ctdb_vnn_map);
CTDB_NO_MEMORY(ctdb, ctdb->vnn_map);
ctdb->vnn_map->generation = map->generation;
ctdb->vnn_map->size = map->size;
ctdb->vnn_map->map = talloc_array(ctdb->vnn_map, uint32_t, map->size);
CTDB_NO_MEMORY(ctdb, ctdb->vnn_map->map);
memcpy(ctdb->vnn_map->map, map->map, sizeof(uint32_t)*map->size);
return 0;
}
int
ctdb_control_getdbmap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
uint32_t i, len;
struct ctdb_db_context *ctdb_db;
struct ctdb_dbid_map *dbid_map;
CHECK_CONTROL_DATA_SIZE(0);
len = 0;
for(ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next){
len++;
}
outdata->dsize = offsetof(struct ctdb_dbid_map, dbs) + sizeof(dbid_map->dbs[0])*len;
outdata->dptr = (unsigned char *)talloc_zero_size(outdata, outdata->dsize);
if (!outdata->dptr) {
DEBUG(0, (__location__ " Failed to allocate dbmap array\n"));
exit(1);
}
dbid_map = (struct ctdb_dbid_map *)outdata->dptr;
dbid_map->num = len;
for (i=0,ctdb_db=ctdb->db_list;ctdb_db;i++,ctdb_db=ctdb_db->next){
dbid_map->dbs[i].dbid = ctdb_db->db_id;
dbid_map->dbs[i].persistent = ctdb_db->persistent;
}
return 0;
}
int
ctdb_control_getnodemap(struct ctdb_context *ctdb, uint32_t opcode, TDB_DATA indata, TDB_DATA *outdata)
{
uint32_t i, num_nodes;
struct ctdb_node_map *node_map;
CHECK_CONTROL_DATA_SIZE(0);
num_nodes = ctdb->num_nodes;
outdata->dsize = offsetof(struct ctdb_node_map, nodes) + num_nodes*sizeof(struct ctdb_node_and_flags);
outdata->dptr = (unsigned char *)talloc_zero_size(outdata, outdata->dsize);
if (!outdata->dptr) {
DEBUG(0, (__location__ " Failed to allocate nodemap array\n"));
exit(1);
}
node_map = (struct ctdb_node_map *)outdata->dptr;
node_map->num = num_nodes;
for (i=0; i<num_nodes; i++) {
inet_aton(ctdb->nodes[i]->address.address, &node_map->nodes[i].sin.sin_addr);
node_map->nodes[i].pnn = ctdb->nodes[i]->pnn;
node_map->nodes[i].flags = ctdb->nodes[i]->flags;
}
return 0;
}
/*
a traverse function for pulling all relevent records from pulldb
*/
struct pulldb_data {
struct ctdb_context *ctdb;
struct ctdb_control_pulldb_reply *pulldata;
uint32_t len;
bool failed;
};
static int traverse_pulldb(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
{
struct pulldb_data *params = (struct pulldb_data *)p;
struct ctdb_rec_data *rec;
/* add the record to the blob */
rec = ctdb_marshall_record(params->pulldata, 0, key, NULL, data);
if (rec == NULL) {
params->failed = true;
return -1;
}
params->pulldata = talloc_realloc_size(NULL, params->pulldata, rec->length + params->len);
if (params->pulldata == NULL) {
DEBUG(0,(__location__ " Failed to expand pulldb_data to %u (%u records)\n",
rec->length + params->len, params->pulldata->count));
params->failed = true;
return -1;
}
params->pulldata->count++;
memcpy(params->len+(uint8_t *)params->pulldata, rec, rec->length);
params->len += rec->length;
talloc_free(rec);
return 0;
}
/*
pul a bunch of records from a ltdb, filtering by lmaster
*/
int32_t ctdb_control_pull_db(struct ctdb_context *ctdb, TDB_DATA indata, TDB_DATA *outdata)
{
struct ctdb_control_pulldb *pull;
struct ctdb_db_context *ctdb_db;
struct pulldb_data params;
struct ctdb_control_pulldb_reply *reply;
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("rejecting ctdb_control_pull_db when not frozen\n"));
return -1;
}
pull = (struct ctdb_control_pulldb *)indata.dptr;
ctdb_db = find_ctdb_db(ctdb, pull->db_id);
if (!ctdb_db) {
DEBUG(0,(__location__ " Unknown db 0x%08x\n", pull->db_id));
return -1;
}
reply = talloc_zero(outdata, struct ctdb_control_pulldb_reply);
CTDB_NO_MEMORY(ctdb, reply);
reply->db_id = pull->db_id;
params.ctdb = ctdb;
params.pulldata = reply;
params.len = offsetof(struct ctdb_control_pulldb_reply, data);
params.failed = false;
if (ctdb_lock_all_databases_mark(ctdb) != 0) {
DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
return -1;
}
if (tdb_traverse_read(ctdb_db->ltdb->tdb, traverse_pulldb, &params) == -1) {
DEBUG(0,(__location__ " Failed to get traverse db '%s'\n", ctdb_db->db_name));
ctdb_lock_all_databases_unmark(ctdb);
talloc_free(params.pulldata);
return -1;
}
ctdb_lock_all_databases_unmark(ctdb);
outdata->dptr = (uint8_t *)params.pulldata;
outdata->dsize = params.len;
return 0;
}
/*
push a bunch of records into a ltdb, filtering by rsn
*/
int32_t ctdb_control_push_db(struct ctdb_context *ctdb, TDB_DATA indata)
{
struct ctdb_control_pulldb_reply *reply = (struct ctdb_control_pulldb_reply *)indata.dptr;
struct ctdb_db_context *ctdb_db;
int i, ret;
struct ctdb_rec_data *rec;
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("rejecting ctdb_control_push_db when not frozen\n"));
return -1;
}
if (indata.dsize < offsetof(struct ctdb_control_pulldb_reply, data)) {
DEBUG(0,(__location__ " invalid data in pulldb reply\n"));
return -1;
}
ctdb_db = find_ctdb_db(ctdb, reply->db_id);
if (!ctdb_db) {
DEBUG(0,(__location__ " Unknown db 0x%08x\n", reply->db_id));
return -1;
}
if (ctdb_lock_all_databases_mark(ctdb) != 0) {
DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
return -1;
}
rec = (struct ctdb_rec_data *)&reply->data[0];
DEBUG(1,("starting push of %u records for dbid 0x%x\n",
reply->count, reply->db_id));
for (i=0;i<reply->count;i++) {
TDB_DATA key, data;
struct ctdb_ltdb_header *hdr;
key.dptr = &rec->data[0];
key.dsize = rec->keylen;
data.dptr = &rec->data[key.dsize];
data.dsize = rec->datalen;
if (data.dsize < sizeof(struct ctdb_ltdb_header)) {
DEBUG(0,(__location__ " bad ltdb record\n"));
goto failed;
}
hdr = (struct ctdb_ltdb_header *)data.dptr;
data.dptr += sizeof(*hdr);
data.dsize -= sizeof(*hdr);
ret = ctdb_ltdb_store(ctdb_db, key, hdr, data);
if (ret != 0) {
DEBUG(0, (__location__ " Unable to store record\n"));
goto failed;
}
rec = (struct ctdb_rec_data *)(rec->length + (uint8_t *)rec);
}
DEBUG(3,("finished push of %u records for dbid 0x%x\n",
reply->count, reply->db_id));
ctdb_lock_all_databases_unmark(ctdb);
return 0;
failed:
ctdb_lock_all_databases_unmark(ctdb);
return -1;
}
static int traverse_setdmaster(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
{
uint32_t *dmaster = (uint32_t *)p;
struct ctdb_ltdb_header *header = (struct ctdb_ltdb_header *)data.dptr;
int ret;
/* skip if already correct */
if (header->dmaster == *dmaster) {
return 0;
}
header->dmaster = *dmaster;
ret = tdb_store(tdb, key, data, TDB_REPLACE);
if (ret) {
DEBUG(0,(__location__ " failed to write tdb data back ret:%d\n",ret));
return ret;
}
/* TODO: add error checking here */
return 0;
}
int32_t ctdb_control_set_dmaster(struct ctdb_context *ctdb, TDB_DATA indata)
{
struct ctdb_control_set_dmaster *p = (struct ctdb_control_set_dmaster *)indata.dptr;
struct ctdb_db_context *ctdb_db;
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("rejecting ctdb_control_set_dmaster when not frozen\n"));
return -1;
}
ctdb_db = find_ctdb_db(ctdb, p->db_id);
if (!ctdb_db) {
DEBUG(0,(__location__ " Unknown db 0x%08x\n", p->db_id));
return -1;
}
if (ctdb_lock_all_databases_mark(ctdb) != 0) {
DEBUG(0,(__location__ " Failed to get lock on entired db - failing\n"));
return -1;
}
tdb_traverse(ctdb_db->ltdb->tdb, traverse_setdmaster, &p->dmaster);
ctdb_lock_all_databases_unmark(ctdb);
return 0;
}
struct ctdb_set_recmode_state {
struct ctdb_context *ctdb;
struct ctdb_req_control *c;
uint32_t recmode;
int fd[2];
struct timed_event *te;
struct fd_event *fde;
pid_t child;
};
/*
called when the 'recovered' event script has finished
*/
static void ctdb_recovered_callback(struct ctdb_context *ctdb, int status, void *p)
{
struct ctdb_set_recmode_state *state = talloc_get_type(p, struct ctdb_set_recmode_state);
ctdb_enable_monitoring(state->ctdb);
if (status == 0) {
ctdb->recovery_mode = state->recmode;
} else {
DEBUG(0,(__location__ " recovered event script failed (status %d)\n", status));
}
ctdb_request_control_reply(ctdb, state->c, NULL, status, NULL);
talloc_free(state);
}
/*
called if our set_recmode child times out. this would happen if
ctdb_recovery_lock() would block.
*/
static void ctdb_set_recmode_timeout(struct event_context *ev, struct timed_event *te,
struct timeval t, void *private_data)
{
struct ctdb_set_recmode_state *state = talloc_get_type(private_data,
struct ctdb_set_recmode_state);
ctdb_request_control_reply(state->ctdb, state->c, NULL, -1, "timeout in ctdb_set_recmode");
talloc_free(state);
}
/* when we free the recmode state we must kill any child process.
*/
static int set_recmode_destructor(struct ctdb_set_recmode_state *state)
{
kill(state->child, SIGKILL);
waitpid(state->child, NULL, 0);
return 0;
}
/* this is called when the client process has completed ctdb_recovery_lock()
and has written data back to us through the pipe.
*/
static void set_recmode_handler(struct event_context *ev, struct fd_event *fde,
uint16_t flags, void *private_data)
{
struct ctdb_set_recmode_state *state= talloc_get_type(private_data,
struct ctdb_set_recmode_state);
char c = 0;
int ret;
/* we got a response from our child process so we can abort the
timeout.
*/
talloc_free(state->te);
state->te = NULL;
/* read the childs status when trying to lock the reclock file.
child wrote 0 if everything is fine and 1 if it did manage
to lock the file, which would be a problem since that means
we got a request to exit from recovery but we could still lock
the file which at this time SHOULD be locked by the recovery
daemon on the recmaster
*/
ret = read(state->fd[0], &c, 1);
if (ret != 1 || c != 0) {
ctdb_request_control_reply(state->ctdb, state->c, NULL, -1, "managed to lock reclock file from inside daemon");
talloc_free(state);
return;
}
ctdb_disable_monitoring(state->ctdb);
/* call the events script to tell all subsystems that we have recovered */
ret = ctdb_event_script_callback(state->ctdb,
timeval_current_ofs(state->ctdb->tunable.script_timeout, 0),
state,
ctdb_recovered_callback,
state, "recovered");
if (ret != 0) {
ctdb_enable_monitoring(state->ctdb);
ctdb_request_control_reply(state->ctdb, state->c, NULL, -1, "failed to run eventscript from set_recmode");
talloc_free(state);
return;
}
}
/*
set the recovery mode
*/
int32_t ctdb_control_set_recmode(struct ctdb_context *ctdb,
struct ctdb_req_control *c,
TDB_DATA indata, bool *async_reply,
const char **errormsg)
{
uint32_t recmode = *(uint32_t *)indata.dptr;
int ret;
struct ctdb_set_recmode_state *state;
pid_t parent = getpid();
if (ctdb->freeze_mode != CTDB_FREEZE_FROZEN) {
DEBUG(0,("Attempt to change recovery mode to %u when not frozen\n",
recmode));
(*errormsg) = "Cannot change recovery mode while not frozen";
return -1;
}
if (recmode != ctdb->recovery_mode) {
DEBUG(0,(__location__ " Recovery mode set to %s\n",
recmode==CTDB_RECOVERY_NORMAL?"NORMAL":"ACTIVE"));
}
if (recmode != CTDB_RECOVERY_NORMAL ||
ctdb->recovery_mode != CTDB_RECOVERY_ACTIVE) {
ctdb->recovery_mode = recmode;
return 0;
}
/* some special handling when ending recovery mode */
state = talloc(ctdb, struct ctdb_set_recmode_state);
CTDB_NO_MEMORY(ctdb, state);
/* For the rest of what needs to be done, we need to do this in
a child process since
1, the call to ctdb_recovery_lock() can block if the cluster
filesystem is in the process of recovery.
2, running of the script may take a while.
*/
ret = pipe(state->fd);
if (ret != 0) {
talloc_free(state);
DEBUG(0,(__location__ " Failed to open pipe for set_recmode child\n"));
return -1;
}
state->child = fork();
if (state->child == (pid_t)-1) {
close(state->fd[0]);
close(state->fd[1]);
talloc_free(state);
return -1;
}
if (state->child == 0) {
char cc = 0;
close(state->fd[0]);
/* we should not be able to get the lock on the nodes list,
as it should be held by the recovery master
*/
if (ctdb_recovery_lock(ctdb, false)) {
DEBUG(0,("ERROR: recovery lock file %s not locked when recovering!\n", ctdb->recovery_lock_file));
cc = 1;
}
write(state->fd[1], &cc, 1);
/* make sure we die when our parent dies */
while (kill(parent, 0) == 0 || errno != ESRCH) {
sleep(5);
}
_exit(0);
}
close(state->fd[1]);
talloc_set_destructor(state, set_recmode_destructor);
state->te = event_add_timed(ctdb->ev, state, timeval_current_ofs(3, 0),
ctdb_set_recmode_timeout, state);
state->fde = event_add_fd(ctdb->ev, state, state->fd[0],
EVENT_FD_READ|EVENT_FD_AUTOCLOSE,
set_recmode_handler,
(void *)state);
if (state->fde == NULL) {
talloc_free(state);
return -1;
}
state->ctdb = ctdb;
state->recmode = recmode;
state->c = talloc_steal(state, c);
*async_reply = true;
return 0;
}
/*
try and get the recovery lock in shared storage - should only work
on the recovery master recovery daemon. Anywhere else is a bug
*/
bool ctdb_recovery_lock(struct ctdb_context *ctdb, bool keep)
{
struct flock lock;
if (ctdb->recovery_lock_fd != -1) {
close(ctdb->recovery_lock_fd);
}
ctdb->recovery_lock_fd = open(ctdb->recovery_lock_file, O_RDWR|O_CREAT, 0600);
if (ctdb->recovery_lock_fd == -1) {
DEBUG(0,("ctdb_recovery_lock: Unable to open %s - (%s)\n",
ctdb->recovery_lock_file, strerror(errno)));
return false;
}
set_close_on_exec(ctdb->recovery_lock_fd);
lock.l_type = F_WRLCK;
lock.l_whence = SEEK_SET;
lock.l_start = 0;
lock.l_len = 1;
lock.l_pid = 0;
if (fcntl(ctdb->recovery_lock_fd, F_SETLK, &lock) != 0) {
close(ctdb->recovery_lock_fd);
ctdb->recovery_lock_fd = -1;
if (keep) {
DEBUG(0,("ctdb_recovery_lock: Failed to get recovery lock on '%s'\n", ctdb->recovery_lock_file));
}
return false;
}
if (!keep) {
close(ctdb->recovery_lock_fd);
ctdb->recovery_lock_fd = -1;
}
DEBUG(0,("ctdb_recovery_lock: Got recovery lock on '%s'\n", ctdb->recovery_lock_file));
return true;
}
/*
delete a record as part of the vacuum process
only delete if we are not lmaster or dmaster, and our rsn is <= the provided rsn
use non-blocking locks
*/
int32_t ctdb_control_delete_record(struct ctdb_context *ctdb, TDB_DATA indata)
{
struct ctdb_rec_data *rec = (struct ctdb_rec_data *)indata.dptr;
struct ctdb_db_context *ctdb_db;
TDB_DATA key, data;
struct ctdb_ltdb_header *hdr, *hdr2;
/* these are really internal tdb functions - but we need them here for
non-blocking lock of the freelist */
int tdb_lock_nonblock(struct tdb_context *tdb, int list, int ltype);
int tdb_unlock(struct tdb_context *tdb, int list, int ltype);
if (indata.dsize < sizeof(uint32_t) || indata.dsize != rec->length) {
DEBUG(0,(__location__ " Bad record size in ctdb_control_delete_record\n"));
return -1;
}
ctdb_db = find_ctdb_db(ctdb, rec->reqid);
if (!ctdb_db) {
DEBUG(0,(__location__ " Unknown db 0x%08x\n", rec->reqid));
return -1;
}
key.dsize = rec->keylen;
key.dptr = &rec->data[0];
data.dsize = rec->datalen;
data.dptr = &rec->data[rec->keylen];
if (ctdb_lmaster(ctdb, &key) == ctdb->pnn) {
DEBUG(2,(__location__ " Called delete on record where we are lmaster\n"));
return -1;
}
if (data.dsize != sizeof(struct ctdb_ltdb_header)) {
DEBUG(0,(__location__ " Bad record size\n"));
return -1;
}
hdr = (struct ctdb_ltdb_header *)data.dptr;
/* use a non-blocking lock */
if (tdb_chainlock_nonblock(ctdb_db->ltdb->tdb, key) != 0) {
return -1;
}
data = tdb_fetch(ctdb_db->ltdb->tdb, key);
if (data.dptr == NULL) {
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
return 0;
}
if (data.dsize < sizeof(struct ctdb_ltdb_header)) {
if (tdb_lock_nonblock(ctdb_db->ltdb->tdb, -1, F_WRLCK) == 0) {
tdb_delete(ctdb_db->ltdb->tdb, key);
tdb_unlock(ctdb_db->ltdb->tdb, -1, F_WRLCK);
DEBUG(0,(__location__ " Deleted corrupt record\n"));
}
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
free(data.dptr);
return 0;
}
hdr2 = (struct ctdb_ltdb_header *)data.dptr;
if (hdr2->rsn > hdr->rsn) {
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
DEBUG(2,(__location__ " Skipping record with rsn=%llu - called with rsn=%llu\n",
(unsigned long long)hdr2->rsn, (unsigned long long)hdr->rsn));
free(data.dptr);
return -1;
}
if (hdr2->dmaster == ctdb->pnn) {
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
DEBUG(2,(__location__ " Attempted delete record where we are the dmaster\n"));
free(data.dptr);
return -1;
}
if (tdb_lock_nonblock(ctdb_db->ltdb->tdb, -1, F_WRLCK) != 0) {
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
free(data.dptr);
return -1;
}
if (tdb_delete(ctdb_db->ltdb->tdb, key) != 0) {
tdb_unlock(ctdb_db->ltdb->tdb, -1, F_WRLCK);
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
DEBUG(2,(__location__ " Failed to delete record\n"));
free(data.dptr);
return -1;
}
tdb_unlock(ctdb_db->ltdb->tdb, -1, F_WRLCK);
tdb_chainunlock(ctdb_db->ltdb->tdb, key);
free(data.dptr);
return 0;
}