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samba-mirror/ctdb/server/ctdb_traverse.c

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/*
efficient async ctdb traverse
Copyright (C) Andrew Tridgell 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 "replace.h"
#include "system/filesys.h"
#include "system/network.h"
#include "system/wait.h"
#include "system/time.h"
#include <talloc.h>
#include <tevent.h>
#include "lib/tdb_wrap/tdb_wrap.h"
#include "lib/util/dlinklist.h"
#include "lib/util/debug.h"
#include "lib/util/samba_util.h"
#include "lib/util/sys_rw.h"
#include "lib/util/util_process.h"
#include "ctdb_private.h"
#include "ctdb_client.h"
#include "common/reqid.h"
#include "common/system.h"
#include "common/common.h"
#include "common/logging.h"
typedef void (*ctdb_traverse_fn_t)(void *private_data, TDB_DATA key, TDB_DATA data);
/*
handle returned to caller - freeing this handler will kill the child and
terminate the traverse
*/
struct ctdb_traverse_local_handle {
struct ctdb_traverse_local_handle *next, *prev;
struct ctdb_db_context *ctdb_db;
int fd[2];
pid_t child;
uint64_t srvid;
uint32_t client_reqid;
uint32_t reqid;
int srcnode;
void *private_data;
ctdb_traverse_fn_t callback;
bool withemptyrecords;
struct tevent_fd *fde;
int records_failed;
int records_sent;
};
/*
* called when traverse is completed by child or on error
*/
static void ctdb_traverse_child_handler(struct tevent_context *ev, struct tevent_fd *fde,
uint16_t flags, void *private_data)
{
struct ctdb_traverse_local_handle *h = talloc_get_type(private_data,
struct ctdb_traverse_local_handle);
ctdb_traverse_fn_t callback = h->callback;
void *p = h->private_data;
int res;
ssize_t n;
/* Read the number of records sent by traverse child */
n = sys_read(h->fd[0], &res, sizeof(res));
if (n < 0 || n != sizeof(res)) {
/* Traverse child failed */
DEBUG(DEBUG_ERR, ("Local traverse failed db:%s reqid:%d\n",
h->ctdb_db->db_name, h->reqid));
} else if (res < 0) {
/* Traverse failed */
res = -res;
DEBUG(DEBUG_ERR, ("Local traverse failed db:%s reqid:%d records:%d\n",
h->ctdb_db->db_name, h->reqid, res));
} else {
DEBUG(DEBUG_INFO, ("Local traverse end db:%s reqid:%d records:%d\n",
h->ctdb_db->db_name, h->reqid, res));
}
callback(p, tdb_null, tdb_null);
}
/*
destroy a in-flight traverse operation
*/
static int traverse_local_destructor(struct ctdb_traverse_local_handle *h)
{
DLIST_REMOVE(h->ctdb_db->traverse, h);
ctdb_kill(h->ctdb_db->ctdb, h->child, SIGKILL);
return 0;
}
/*
callback from tdb_traverse_read()
*/
static int ctdb_traverse_local_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *p)
{
struct ctdb_traverse_local_handle *h = talloc_get_type(p,
struct ctdb_traverse_local_handle);
struct ctdb_rec_data_old *d;
struct ctdb_ltdb_header *hdr;
int res, status;
TDB_DATA outdata;
hdr = (struct ctdb_ltdb_header *)data.dptr;
if (h->ctdb_db->persistent == 0) {
/* filter out zero-length records */
if (!h->withemptyrecords &&
data.dsize <= sizeof(struct ctdb_ltdb_header))
{
return 0;
}
/* filter out non-authoritative records */
if (hdr->dmaster != h->ctdb_db->ctdb->pnn) {
return 0;
}
}
d = ctdb_marshall_record(h, h->reqid, key, NULL, data);
if (d == NULL) {
/* error handling is tricky in this child code .... */
h->records_failed++;
return -1;
}
outdata.dptr = (uint8_t *)d;
outdata.dsize = d->length;
res = ctdb_control(h->ctdb_db->ctdb, h->srcnode, 0, CTDB_CONTROL_TRAVERSE_DATA,
CTDB_CTRL_FLAG_NOREPLY, outdata, NULL, NULL, &status, NULL, NULL);
if (res != 0 || status != 0) {
h->records_failed++;
return -1;
}
h->records_sent++;
return 0;
}
struct traverse_all_state {
struct ctdb_context *ctdb;
struct ctdb_traverse_local_handle *h;
uint32_t reqid;
uint32_t srcnode;
uint32_t client_reqid;
uint64_t srvid;
bool withemptyrecords;
};
/*
setup a non-blocking traverse of a local ltdb. The callback function
will be called on every record in the local ltdb. To stop the
traverse, talloc_free() the traverse_handle.
The traverse is finished when the callback is called with tdb_null for key and data
*/
static struct ctdb_traverse_local_handle *ctdb_traverse_local(struct ctdb_db_context *ctdb_db,
ctdb_traverse_fn_t callback,
struct traverse_all_state *all_state)
{
struct ctdb_traverse_local_handle *h;
int ret;
h = talloc_zero(all_state, struct ctdb_traverse_local_handle);
if (h == NULL) {
return NULL;
}
ret = pipe(h->fd);
if (ret != 0) {
talloc_free(h);
return NULL;
}
h->child = ctdb_fork(ctdb_db->ctdb);
if (h->child == (pid_t)-1) {
close(h->fd[0]);
close(h->fd[1]);
talloc_free(h);
return NULL;
}
h->callback = callback;
h->private_data = all_state;
h->ctdb_db = ctdb_db;
h->client_reqid = all_state->client_reqid;
h->reqid = all_state->reqid;
h->srvid = all_state->srvid;
h->srcnode = all_state->srcnode;
h->withemptyrecords = all_state->withemptyrecords;
if (h->child == 0) {
/* start the traverse in the child */
int res, status;
pid_t parent = getpid();
struct ctdb_context *ctdb = ctdb_db->ctdb;
struct ctdb_rec_data_old *d;
TDB_DATA outdata;
close(h->fd[0]);
prctl_set_comment("ctdb_traverse");
if (switch_from_server_to_client(ctdb) != 0) {
DEBUG(DEBUG_CRIT, ("Failed to switch traverse child into client mode\n"));
_exit(0);
}
d = ctdb_marshall_record(h, h->reqid, tdb_null, NULL, tdb_null);
if (d == NULL) {
res = 0;
sys_write(h->fd[1], &res, sizeof(int));
_exit(0);
}
res = tdb_traverse_read(ctdb_db->ltdb->tdb, ctdb_traverse_local_fn, h);
if (res == -1 || h->records_failed > 0) {
/* traverse failed */
res = -(h->records_sent);
} else {
res = h->records_sent;
}
/* Wait till all the data is flushed from output queue */
while (ctdb_queue_length(ctdb->daemon.queue) > 0) {
tevent_loop_once(ctdb->ev);
}
/* End traverse by sending empty record */
outdata.dptr = (uint8_t *)d;
outdata.dsize = d->length;
ret = ctdb_control(ctdb, h->srcnode, 0,
CTDB_CONTROL_TRAVERSE_DATA,
CTDB_CTRL_FLAG_NOREPLY, outdata,
NULL, NULL, &status, NULL, NULL);
if (ret == -1 || status == -1) {
if (res > 0) {
res = -res;
}
}
sys_write(h->fd[1], &res, sizeof(res));
ctdb_wait_for_process_to_exit(parent);
_exit(0);
}
close(h->fd[1]);
set_close_on_exec(h->fd[0]);
talloc_set_destructor(h, traverse_local_destructor);
DLIST_ADD(ctdb_db->traverse, h);
h->fde = tevent_add_fd(ctdb_db->ctdb->ev, h, h->fd[0], TEVENT_FD_READ,
ctdb_traverse_child_handler, h);
if (h->fde == NULL) {
close(h->fd[0]);
talloc_free(h);
return NULL;
}
tevent_fd_set_auto_close(h->fde);
return h;
}
struct ctdb_traverse_all_handle {
struct ctdb_context *ctdb;
struct ctdb_db_context *ctdb_db;
uint32_t reqid;
ctdb_traverse_fn_t callback;
void *private_data;
uint32_t null_count;
bool timedout;
};
/*
destroy a traverse_all op
*/
static int ctdb_traverse_all_destructor(struct ctdb_traverse_all_handle *state)
{
reqid_remove(state->ctdb->idr, state->reqid);
return 0;
}
/* called when a traverse times out */
static void ctdb_traverse_all_timeout(struct tevent_context *ev,
struct tevent_timer *te,
struct timeval t, void *private_data)
{
struct ctdb_traverse_all_handle *state = talloc_get_type(private_data, struct ctdb_traverse_all_handle);
DEBUG(DEBUG_ERR,(__location__ " Traverse all timeout on database:%s\n", state->ctdb_db->db_name));
CTDB_INCREMENT_STAT(state->ctdb, timeouts.traverse);
state->timedout = true;
state->callback(state->private_data, tdb_null, tdb_null);
}
struct traverse_start_state {
struct ctdb_context *ctdb;
struct ctdb_traverse_all_handle *h;
uint32_t srcnode;
uint32_t reqid;
uint32_t db_id;
uint64_t srvid;
bool withemptyrecords;
int num_records;
};
/*
setup a cluster-wide non-blocking traverse of a ctdb. The
callback function will be called on every record in the local
ltdb. To stop the traverse, talloc_free() the traverse_handle.
The traverse is finished when the callback is called with tdb_null
for key and data
*/
static struct ctdb_traverse_all_handle *ctdb_daemon_traverse_all(struct ctdb_db_context *ctdb_db,
ctdb_traverse_fn_t callback,
struct traverse_start_state *start_state)
{
struct ctdb_traverse_all_handle *state;
struct ctdb_context *ctdb = ctdb_db->ctdb;
int ret;
TDB_DATA data;
struct ctdb_traverse_all r;
struct ctdb_traverse_all_ext r_ext;
uint32_t destination;
state = talloc(start_state, struct ctdb_traverse_all_handle);
if (state == NULL) {
return NULL;
}
state->ctdb = ctdb;
state->ctdb_db = ctdb_db;
state->reqid = reqid_new(ctdb_db->ctdb->idr, state);
state->callback = callback;
state->private_data = start_state;
state->null_count = 0;
state->timedout = false;
talloc_set_destructor(state, ctdb_traverse_all_destructor);
if (start_state->withemptyrecords) {
r_ext.db_id = ctdb_db->db_id;
r_ext.reqid = state->reqid;
r_ext.pnn = ctdb->pnn;
r_ext.client_reqid = start_state->reqid;
r_ext.srvid = start_state->srvid;
r_ext.withemptyrecords = start_state->withemptyrecords;
data.dptr = (uint8_t *)&r_ext;
data.dsize = sizeof(r_ext);
} else {
r.db_id = ctdb_db->db_id;
r.reqid = state->reqid;
r.pnn = ctdb->pnn;
r.client_reqid = start_state->reqid;
r.srvid = start_state->srvid;
data.dptr = (uint8_t *)&r;
data.dsize = sizeof(r);
}
if (ctdb_db->persistent == 0) {
/* normal database, traverse all nodes */
destination = CTDB_BROADCAST_VNNMAP;
} else {
int i;
/* persistent database, traverse one node, preferably
* the local one
*/
destination = ctdb->pnn;
/* check we are in the vnnmap */
for (i=0; i < ctdb->vnn_map->size; i++) {
if (ctdb->vnn_map->map[i] == ctdb->pnn) {
break;
}
}
/* if we are not in the vnn map we just pick the first
* node instead
*/
if (i == ctdb->vnn_map->size) {
destination = ctdb->vnn_map->map[0];
}
}
/* tell all the nodes in the cluster to start sending records to this
* node, or if it is a persistent database, just tell the local
* node
*/
if (start_state->withemptyrecords) {
ret = ctdb_daemon_send_control(ctdb, destination, 0,
CTDB_CONTROL_TRAVERSE_ALL_EXT,
0, CTDB_CTRL_FLAG_NOREPLY, data, NULL, NULL);
} else {
ret = ctdb_daemon_send_control(ctdb, destination, 0,
CTDB_CONTROL_TRAVERSE_ALL,
0, CTDB_CTRL_FLAG_NOREPLY, data, NULL, NULL);
}
if (ret != 0) {
talloc_free(state);
return NULL;
}
DEBUG(DEBUG_NOTICE,("Starting traverse on DB %s (id %d)\n",
ctdb_db->db_name, state->reqid));
/* timeout the traverse */
tevent_add_timer(ctdb->ev, state,
timeval_current_ofs(ctdb->tunable.traverse_timeout, 0),
ctdb_traverse_all_timeout, state);
return state;
}
/*
called when local traverse ends
*/
static void traverse_all_callback(void *p, TDB_DATA key, TDB_DATA data)
{
struct traverse_all_state *state = talloc_get_type(p, struct traverse_all_state);
/* we're done */
talloc_free(state);
}
/*
* extended version to take the "withemptyrecords" parameter"
*/
int32_t ctdb_control_traverse_all_ext(struct ctdb_context *ctdb, TDB_DATA data, TDB_DATA *outdata)
{
struct ctdb_traverse_all_ext *c = (struct ctdb_traverse_all_ext *)data.dptr;
struct traverse_all_state *state;
struct ctdb_db_context *ctdb_db;
if (data.dsize != sizeof(struct ctdb_traverse_all_ext)) {
DEBUG(DEBUG_ERR,(__location__ " Invalid size in ctdb_control_traverse_all_ext\n"));
return -1;
}
ctdb_db = find_ctdb_db(ctdb, c->db_id);
if (ctdb_db == NULL) {
return -1;
}
if (ctdb_db->unhealthy_reason) {
if (ctdb->tunable.allow_unhealthy_db_read == 0) {
DEBUG(DEBUG_ERR,("db(%s) unhealty in ctdb_control_traverse_all: %s\n",
ctdb_db->db_name, ctdb_db->unhealthy_reason));
return -1;
}
DEBUG(DEBUG_WARNING,("warn: db(%s) unhealty in ctdb_control_traverse_all: %s\n",
ctdb_db->db_name, ctdb_db->unhealthy_reason));
}
state = talloc(ctdb_db, struct traverse_all_state);
if (state == NULL) {
return -1;
}
state->reqid = c->reqid;
state->srcnode = c->pnn;
state->ctdb = ctdb;
state->client_reqid = c->client_reqid;
state->srvid = c->srvid;
state->withemptyrecords = c->withemptyrecords;
state->h = ctdb_traverse_local(ctdb_db, traverse_all_callback, state);
if (state->h == NULL) {
talloc_free(state);
return -1;
}
return 0;
}
/*
called when a CTDB_CONTROL_TRAVERSE_ALL control comes in. We then
setup a traverse of our local ltdb, sending the records as
CTDB_CONTROL_TRAVERSE_DATA records back to the originator
*/
int32_t ctdb_control_traverse_all(struct ctdb_context *ctdb, TDB_DATA data, TDB_DATA *outdata)
{
struct ctdb_traverse_all *c = (struct ctdb_traverse_all *)data.dptr;
struct traverse_all_state *state;
struct ctdb_db_context *ctdb_db;
if (data.dsize != sizeof(struct ctdb_traverse_all)) {
DEBUG(DEBUG_ERR,(__location__ " Invalid size in ctdb_control_traverse_all\n"));
return -1;
}
ctdb_db = find_ctdb_db(ctdb, c->db_id);
if (ctdb_db == NULL) {
return -1;
}
if (ctdb_db->unhealthy_reason) {
if (ctdb->tunable.allow_unhealthy_db_read == 0) {
DEBUG(DEBUG_ERR,("db(%s) unhealty in ctdb_control_traverse_all: %s\n",
ctdb_db->db_name, ctdb_db->unhealthy_reason));
return -1;
}
DEBUG(DEBUG_WARNING,("warn: db(%s) unhealty in ctdb_control_traverse_all: %s\n",
ctdb_db->db_name, ctdb_db->unhealthy_reason));
}
state = talloc(ctdb_db, struct traverse_all_state);
if (state == NULL) {
return -1;
}
state->reqid = c->reqid;
state->srcnode = c->pnn;
state->ctdb = ctdb;
state->client_reqid = c->client_reqid;
state->srvid = c->srvid;
state->withemptyrecords = false;
state->h = ctdb_traverse_local(ctdb_db, traverse_all_callback, state);
if (state->h == NULL) {
talloc_free(state);
return -1;
}
return 0;
}
/*
called when a CTDB_CONTROL_TRAVERSE_DATA control comes in. We then
call the traverse_all callback with the record
*/
int32_t ctdb_control_traverse_data(struct ctdb_context *ctdb, TDB_DATA data, TDB_DATA *outdata)
{
struct ctdb_rec_data_old *d = (struct ctdb_rec_data_old *)data.dptr;
struct ctdb_traverse_all_handle *state;
TDB_DATA key;
ctdb_traverse_fn_t callback;
void *private_data;
if (data.dsize < sizeof(uint32_t) || data.dsize != d->length) {
DEBUG(DEBUG_ERR,("Bad record size in ctdb_control_traverse_data\n"));
return -1;
}
state = reqid_find(ctdb->idr, d->reqid, struct ctdb_traverse_all_handle);
if (state == NULL || d->reqid != state->reqid) {
/* traverse might have been terminated already */
return -1;
}
key.dsize = d->keylen;
key.dptr = &d->data[0];
data.dsize = d->datalen;
data.dptr = &d->data[d->keylen];
if (key.dsize == 0 && data.dsize == 0) {
state->null_count++;
/* Persistent databases are only scanned on one node (the local
* node)
*/
if (state->ctdb_db->persistent == 0) {
if (state->null_count != ctdb_get_num_active_nodes(ctdb)) {
return 0;
}
}
}
callback = state->callback;
private_data = state->private_data;
callback(private_data, key, data);
return 0;
}
/*
kill a in-progress traverse, used when a client disconnects
*/
int32_t ctdb_control_traverse_kill(struct ctdb_context *ctdb, TDB_DATA data,
TDB_DATA *outdata, uint32_t srcnode)
{
struct ctdb_traverse_start *d = (struct ctdb_traverse_start *)data.dptr;
struct ctdb_db_context *ctdb_db;
struct ctdb_traverse_local_handle *t;
ctdb_db = find_ctdb_db(ctdb, d->db_id);
if (ctdb_db == NULL) {
return -1;
}
for (t=ctdb_db->traverse; t; t=t->next) {
if (t->client_reqid == d->reqid &&
t->srvid == d->srvid) {
talloc_free(t);
break;
}
}
return 0;
}
/*
this is called when a client disconnects during a traverse
we need to notify all the nodes taking part in the search that they
should kill their traverse children
*/
static int ctdb_traverse_start_destructor(struct traverse_start_state *state)
{
struct ctdb_traverse_start r;
TDB_DATA data;
DEBUG(DEBUG_ERR,(__location__ " Traverse cancelled by client disconnect for database:0x%08x\n", state->db_id));
r.db_id = state->db_id;
r.reqid = state->reqid;
r.srvid = state->srvid;
data.dptr = (uint8_t *)&r;
data.dsize = sizeof(r);
ctdb_daemon_send_control(state->ctdb, CTDB_BROADCAST_CONNECTED, 0,
CTDB_CONTROL_TRAVERSE_KILL,
0, CTDB_CTRL_FLAG_NOREPLY, data, NULL, NULL);
return 0;
}
/*
callback which sends records as messages to the client
*/
static void traverse_start_callback(void *p, TDB_DATA key, TDB_DATA data)
{
struct traverse_start_state *state;
struct ctdb_rec_data_old *d;
TDB_DATA cdata;
state = talloc_get_type(p, struct traverse_start_state);
d = ctdb_marshall_record(state, state->reqid, key, NULL, data);
if (d == NULL) {
return;
}
cdata.dptr = (uint8_t *)d;
cdata.dsize = d->length;
srvid_dispatch(state->ctdb->srv, state->srvid, 0, cdata);
if (key.dsize == 0 && data.dsize == 0) {
DEBUG(DEBUG_NOTICE, ("Ending traverse on DB %s (id %d), records %d\n",
state->h->ctdb_db->db_name, state->h->reqid,
state->num_records));
if (state->h->timedout) {
/* timed out, send TRAVERSE_KILL control */
talloc_free(state);
} else {
/* end of traverse */
talloc_set_destructor(state, NULL);
talloc_free(state);
}
} else {
state->num_records++;
}
}
/**
* start a traverse_all - called as a control from a client.
* extended version to take the "withemptyrecords" parameter.
*/
int32_t ctdb_control_traverse_start_ext(struct ctdb_context *ctdb,
TDB_DATA data,
TDB_DATA *outdata,
uint32_t srcnode,
uint32_t client_id)
{
struct ctdb_traverse_start_ext *d = (struct ctdb_traverse_start_ext *)data.dptr;
struct traverse_start_state *state;
struct ctdb_db_context *ctdb_db;
struct ctdb_client *client = reqid_find(ctdb->idr, client_id, struct ctdb_client);
if (client == NULL) {
DEBUG(DEBUG_ERR,(__location__ " No client found\n"));
return -1;
}
if (data.dsize != sizeof(*d)) {
DEBUG(DEBUG_ERR,("Bad record size in ctdb_control_traverse_start\n"));
return -1;
}
ctdb_db = find_ctdb_db(ctdb, d->db_id);
if (ctdb_db == NULL) {
return -1;
}
if (ctdb_db->unhealthy_reason) {
if (ctdb->tunable.allow_unhealthy_db_read == 0) {
DEBUG(DEBUG_ERR,("db(%s) unhealty in ctdb_control_traverse_start: %s\n",
ctdb_db->db_name, ctdb_db->unhealthy_reason));
return -1;
}
DEBUG(DEBUG_WARNING,("warn: db(%s) unhealty in ctdb_control_traverse_start: %s\n",
ctdb_db->db_name, ctdb_db->unhealthy_reason));
}
state = talloc(client, struct traverse_start_state);
if (state == NULL) {
return -1;
}
state->srcnode = srcnode;
state->reqid = d->reqid;
state->srvid = d->srvid;
state->db_id = d->db_id;
state->ctdb = ctdb;
state->withemptyrecords = d->withemptyrecords;
state->num_records = 0;
state->h = ctdb_daemon_traverse_all(ctdb_db, traverse_start_callback, state);
if (state->h == NULL) {
talloc_free(state);
return -1;
}
talloc_set_destructor(state, ctdb_traverse_start_destructor);
return 0;
}
/**
* start a traverse_all - called as a control from a client.
*/
int32_t ctdb_control_traverse_start(struct ctdb_context *ctdb,
TDB_DATA data,
TDB_DATA *outdata,
uint32_t srcnode,
uint32_t client_id)
{
struct ctdb_traverse_start *d = (struct ctdb_traverse_start *)data.dptr;
struct ctdb_traverse_start_ext d2;
TDB_DATA data2;
ZERO_STRUCT(d2);
d2.db_id = d->db_id;
d2.reqid = d->reqid;
d2.srvid = d->srvid;
d2.withemptyrecords = false;
data2.dsize = sizeof(d2);
data2.dptr = (uint8_t *)&d2;
return ctdb_control_traverse_start_ext(ctdb, data2, outdata, srcnode, client_id);
}