/*!
* \brief Main interaction loop for the recovery manager
*
* The recovery light-weight process only runs when you're the
* synchronization site. It performs the following tasks, if and only
* if the prerequisite tasks have been performed successfully (it
* keeps track of which ones have been performed in its bit map,
* \p urecovery_state).
*
* First, it is responsible for probing that all servers are up. This
* is the only operation that must be performed even if this is not
* yet the sync site, since otherwise this site may not notice that
* enough other machines are running to even elect this guy to be the
* sync site.
*
* After that, the recovery process does nothing until the beacon and
* voting modules manage to get this site elected sync site.
*
* After becoming sync site, recovery first attempts to find the best
* database available in the network (it must do this in order to
* ensure finding the latest committed data). After finding the right
* database, it must fetch this dbase to the sync site.
*
* After fetching the dbase, it relabels it with a new version number,
* to ensure that everyone recognizes this dbase as the most recent
* dbase.
*
* One the dbase has been relabelled, this machine can start handling
* requests. However, the recovery module still has one more task:
* propagating the dbase out to everyone who is up in the network.
*/
void *
urecovery_Interact(void *dummy)
{
afs_int32 code, tcode;
struct ubik_server *bestServer = NULL;
struct ubik_server *ts;
int dbok, doingRPC, now;
afs_int32 lastProbeTime;
/* if we're the sync site, the best db version we've found yet */
static struct ubik_version bestDBVersion;
struct ubik_version tversion;
struct timeval tv;
int length, tlen, offset, file, nbytes;
struct rx_call *rxcall;
char tbuffer[1024];
struct ubik_stat ubikstat;
struct in_addr inAddr;
char hoststr[16];
char pbuffer[1028];
int fd = -1;
afs_int32 pass;
afs_pthread_setname_self("recovery");
/* otherwise, begin interaction */
urecovery_state = 0;
lastProbeTime = 0;
while (1) {
/* Run through this loop every 4 seconds */
tv.tv_sec = 4;
tv.tv_usec = 0;
#ifdef AFS_PTHREAD_ENV
select(0, 0, 0, 0, &tv);
#else
IOMGR_Select(0, 0, 0, 0, &tv);
#endif
ubik_dprint("recovery running in state %x\n", urecovery_state);
/* Every 30 seconds, check all the down servers and mark them
* as up if they respond. When a server comes up or found to
* not be current, then re-find the the best database and
* propogate it.
*/
if ((now = FT_ApproxTime()) > 30 + lastProbeTime) {
for (ts = ubik_servers, doingRPC = 0; ts; ts = ts->next) {
UBIK_BEACON_LOCK;
if (!ts->up) {
UBIK_BEACON_UNLOCK;
doingRPC = 1;
code = DoProbe(ts);
if (code == 0) {
UBIK_BEACON_LOCK;
ts->up = 1;
UBIK_BEACON_UNLOCK;
DBHOLD(ubik_dbase);
urecovery_state &= ~UBIK_RECFOUNDDB;
DBRELE(ubik_dbase);
}
} else {
UBIK_BEACON_UNLOCK;
DBHOLD(ubik_dbase);
if (!ts->currentDB)
urecovery_state &= ~UBIK_RECFOUNDDB;
DBRELE(ubik_dbase);
}
}
if (doingRPC)
now = FT_ApproxTime();
lastProbeTime = now;
}
/* Mark whether we are the sync site */
DBHOLD(ubik_dbase);
if (!ubeacon_AmSyncSite()) {
urecovery_state &= ~UBIK_RECSYNCSITE;
DBRELE(ubik_dbase);
continue; /* nothing to do */
}
urecovery_state |= UBIK_RECSYNCSITE;
/* If a server has just come up or if we have not found the
* most current database, then go find the most current db.
*/
if (!(urecovery_state & UBIK_RECFOUNDDB)) {
DBRELE(ubik_dbase);
bestServer = (struct ubik_server *)0;
bestDBVersion.epoch = 0;
bestDBVersion.counter = 0;
for (ts = ubik_servers; ts; ts = ts->next) {
UBIK_BEACON_LOCK;
if (!ts->up) {
UBIK_BEACON_UNLOCK;
continue; /* don't bother with these guys */
}
UBIK_BEACON_UNLOCK;
if (ts->isClone)
continue;
UBIK_ADDR_LOCK;
code = DISK_GetVersion(ts->disk_rxcid, &ts->version);
UBIK_ADDR_UNLOCK;
if (code == 0) {
/* perhaps this is the best version */
if (vcmp(ts->version, bestDBVersion) > 0) {
/* new best version */
bestDBVersion = ts->version;
bestServer = ts;
}
}
}
/* take into consideration our version. Remember if we,
* the sync site, have the best version. Also note that
* we may need to send the best version out.
*/
DBHOLD(ubik_dbase);
if (vcmp(ubik_dbase->version, bestDBVersion) >= 0) {
bestDBVersion = ubik_dbase->version;
bestServer = (struct ubik_server *)0;
urecovery_state |= UBIK_RECHAVEDB;
} else {
/* Clear the flag only when we know we have to retrieve
* the db. Because urecovery_AllBetter() looks at it.
*/
urecovery_state &= ~UBIK_RECHAVEDB;
}
urecovery_state |= UBIK_RECFOUNDDB;
urecovery_state &= ~UBIK_RECSENTDB;
}
if (!(urecovery_state & UBIK_RECFOUNDDB)) {
DBRELE(ubik_dbase);
continue; /* not ready */
}
/* If we, the sync site, do not have the best db version, then
* go and get it from the server that does.
*/
if ((urecovery_state & UBIK_RECHAVEDB) || !bestServer) {
urecovery_state |= UBIK_RECHAVEDB;
} else {
/* we don't have the best version; we should fetch it. */
urecovery_AbortAll(ubik_dbase);
/* Rx code to do the Bulk fetch */
file = 0;
offset = 0;
UBIK_ADDR_LOCK;
rxcall = rx_NewCall(bestServer->disk_rxcid);
ubik_print("Ubik: Synchronize database with server %s\n",
afs_inet_ntoa_r(bestServer->addr[0], hoststr));
UBIK_ADDR_UNLOCK;
code = StartDISK_GetFile(rxcall, file);
if (code) {
ubik_dprint("StartDiskGetFile failed=%d\n", code);
goto FetchEndCall;
}
nbytes = rx_Read(rxcall, (char *)&length, sizeof(afs_int32));
length = ntohl(length);
if (nbytes != sizeof(afs_int32)) {
ubik_dprint("Rx-read length error=%d\n", code = BULK_ERROR);
code = EIO;
goto FetchEndCall;
}
/* give invalid label during file transit */
UBIK_VERSION_LOCK;
tversion.epoch = 0;
code = (*ubik_dbase->setlabel) (ubik_dbase, file, &tversion);
UBIK_VERSION_UNLOCK;
if (code) {
ubik_dprint("setlabel io error=%d\n", code);
goto FetchEndCall;
}
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.TMP",
ubik_dbase->pathName, (file<0)?"SYS":"",
(file<0)?-file:file);
fd = open(pbuffer, O_CREAT | O_RDWR | O_TRUNC, 0600);
if (fd < 0) {
code = errno;
goto FetchEndCall;
}
code = lseek(fd, HDRSIZE, 0);
if (code != HDRSIZE) {
close(fd);
goto FetchEndCall;
}
pass = 0;
while (length > 0) {
tlen = (length > sizeof(tbuffer) ? sizeof(tbuffer) : length);
#ifndef AFS_PTHREAD_ENV
if (pass % 4 == 0)
IOMGR_Poll();
#endif
nbytes = rx_Read(rxcall, tbuffer, tlen);
if (nbytes != tlen) {
ubik_dprint("Rx-read bulk error=%d\n", code = BULK_ERROR);
code = EIO;
close(fd);
goto FetchEndCall;
}
nbytes = write(fd, tbuffer, tlen);
pass++;
if (nbytes != tlen) {
code = UIOERROR;
close(fd);
goto FetchEndCall;
}
offset += tlen;
length -= tlen;
}
code = close(fd);
if (code)
goto FetchEndCall;
code = EndDISK_GetFile(rxcall, &tversion);
FetchEndCall:
tcode = rx_EndCall(rxcall, code);
if (!code)
code = tcode;
if (!code) {
/* we got a new file, set up its header */
urecovery_state |= UBIK_RECHAVEDB;
UBIK_VERSION_LOCK;
memcpy(&ubik_dbase->version, &tversion,
sizeof(struct ubik_version));
snprintf(tbuffer, sizeof(tbuffer), "%s.DB%s%d",
ubik_dbase->pathName, (file<0)?"SYS":"",
(file<0)?-file:file);
#ifdef AFS_NT40_ENV
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.OLD",
ubik_dbase->pathName, (file<0)?"SYS":"",
(file<0)?-file:file);
code = unlink(pbuffer);
if (!code)
code = rename(tbuffer, pbuffer);
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.TMP",
ubik_dbase->pathName, (file<0)?"SYS":"",
(file<0)?-file:file);
#endif
if (!code)
code = rename(pbuffer, tbuffer);
if (!code) {
(*ubik_dbase->open) (ubik_dbase, file);
/* after data is good, sync disk with correct label */
code =
(*ubik_dbase->setlabel) (ubik_dbase, 0,
&ubik_dbase->version);
}
UBIK_VERSION_UNLOCK;
#ifdef AFS_NT40_ENV
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.OLD",
ubik_dbase->pathName, (file<0)?"SYS":"",
(file<0)?-file:file);
unlink(pbuffer);
#endif
}
if (code) {
unlink(pbuffer);
/*
* We will effectively invalidate the old data forever now.
* Unclear if we *should* but we do.
*/
UBIK_VERSION_LOCK;
ubik_dbase->version.epoch = 0;
ubik_dbase->version.counter = 0;
UBIK_VERSION_UNLOCK;
ubik_print("Ubik: Synchronize database failed (error = %d)\n",
code);
} else {
ubik_print("Ubik: Synchronize database completed\n");
urecovery_state |= UBIK_RECHAVEDB;
}
udisk_Invalidate(ubik_dbase, 0); /* data has changed */
#ifdef AFS_PTHREAD_ENV
CV_BROADCAST(&ubik_dbase->version_cond);
#else
LWP_NoYieldSignal(&ubik_dbase->version);
#endif
}
if (!(urecovery_state & UBIK_RECHAVEDB)) {
DBRELE(ubik_dbase);
continue; /* not ready */
}
/* If the database was newly initialized, then when we establish quorum, write
* a new label. This allows urecovery_AllBetter() to allow access for reads.
* Setting it to 2 also allows another site to come along with a newer
* database and overwrite this one.
*/
if (ubik_dbase->version.epoch == 1) {
urecovery_AbortAll(ubik_dbase);
UBIK_VERSION_LOCK;
version_globals.ubik_epochTime = 2;
ubik_dbase->version.epoch = version_globals.ubik_epochTime;
ubik_dbase->version.counter = 1;
code =
(*ubik_dbase->setlabel) (ubik_dbase, 0, &ubik_dbase->version);
UBIK_VERSION_UNLOCK;
udisk_Invalidate(ubik_dbase, 0); /* data may have changed */
#ifdef AFS_PTHREAD_ENV
CV_BROADCAST(&ubik_dbase->version_cond);
#else
LWP_NoYieldSignal(&ubik_dbase->version);
#endif
}
/* Check the other sites and send the database to them if they
* do not have the current db.
*/
if (!(urecovery_state & UBIK_RECSENTDB)) {
/* now propagate out new version to everyone else */
dbok = 1; /* start off assuming they all worked */
/*
* Check if a write transaction is in progress. We can't send the
* db when a write is in progress here because the db would be
* obsolete as soon as it goes there. Also, ops after the begin
* trans would reach the recepient and wouldn't find a transaction
* pending there. Frankly, I don't think it's possible to get past
* the write-lock above if there is a write transaction in progress,
* but then, it won't hurt to check, will it?
*/
if (ubik_dbase->flags & DBWRITING) {
struct timeval tv;
int safety = 0;
long cur_usec = 50000;
while ((ubik_dbase->flags & DBWRITING) && (safety < 500)) {
DBRELE(ubik_dbase);
/* sleep for a little while */
tv.tv_sec = 0;
tv.tv_usec = cur_usec;
#ifdef AFS_PTHREAD_ENV
select(0, 0, 0, 0, &tv);
#else
IOMGR_Select(0, 0, 0, 0, &tv);
#endif
cur_usec += 10000;
safety++;
DBHOLD(ubik_dbase);
}
}
for (ts = ubik_servers; ts; ts = ts->next) {
UBIK_ADDR_LOCK;
inAddr.s_addr = ts->addr[0];
UBIK_ADDR_UNLOCK;
UBIK_BEACON_LOCK;
if (!ts->up) {
UBIK_BEACON_UNLOCK;
ubik_dprint("recovery cannot send version to %s\n",
afs_inet_ntoa_r(inAddr.s_addr, hoststr));
dbok = 0;
continue;
}
UBIK_BEACON_UNLOCK;
ubik_dprint("recovery sending version to %s\n",
afs_inet_ntoa_r(inAddr.s_addr, hoststr));
if (vcmp(ts->version, ubik_dbase->version) != 0) {
ubik_dprint("recovery stating local database\n");
/* Rx code to do the Bulk Store */
code = (*ubik_dbase->stat) (ubik_dbase, 0, &ubikstat);
if (!code) {
length = ubikstat.size;
file = offset = 0;
UBIK_ADDR_LOCK;
rxcall = rx_NewCall(ts->disk_rxcid);
UBIK_ADDR_UNLOCK;
code =
StartDISK_SendFile(rxcall, file, length,
&ubik_dbase->version);
if (code) {
ubik_dprint("StartDiskSendFile failed=%d\n",
code);
goto StoreEndCall;
}
while (length > 0) {
tlen =
(length >
sizeof(tbuffer) ? sizeof(tbuffer) : length);
nbytes =
(*ubik_dbase->read) (ubik_dbase, file,
tbuffer, offset, tlen);
if (nbytes != tlen) {
ubik_dprint("Local disk read error=%d\n",
code = UIOERROR);
goto StoreEndCall;
}
nbytes = rx_Write(rxcall, tbuffer, tlen);
if (nbytes != tlen) {
ubik_dprint("Rx-write bulk error=%d\n", code =
BULK_ERROR);
goto StoreEndCall;
}
offset += tlen;
length -= tlen;
}
code = EndDISK_SendFile(rxcall);
StoreEndCall:
code = rx_EndCall(rxcall, code);
}
if (code == 0) {
/* we set a new file, process its header */
ts->version = ubik_dbase->version;
ts->currentDB = 1;
} else
dbok = 0;
} else {
/* mark file up to date */
ts->currentDB = 1;
}
}
if (dbok)
urecovery_state |= UBIK_RECSENTDB;
}
DBRELE(ubik_dbase);
}
return NULL;
}
afs_int32
SDISK_SendFile(struct rx_call *rxcall, afs_int32 file,
afs_int32 length, struct ubik_version *avers)
{
afs_int32 code;
struct ubik_dbase *dbase = NULL;
char tbuffer[1024];
afs_int32 offset;
struct ubik_version tversion;
int tlen;
struct rx_peer *tpeer;
struct rx_connection *tconn;
afs_uint32 otherHost = 0;
char hoststr[16];
char pbuffer[1028];
int fd = -1;
afs_int32 epoch = 0;
afs_int32 pass;
/* send the file back to the requester */
dbase = ubik_dbase;
if ((code = ubik_CheckAuth(rxcall))) {
DBHOLD(dbase);
goto failed;
}
/* next, we do a sanity check to see if the guy sending us the database is
* the guy we think is the sync site. It turns out that we might not have
* decided yet that someone's the sync site, but they could have enough
* votes from others to be sync site anyway, and could send us the database
* in advance of getting our votes. This is fine, what we're really trying
* to check is that some authenticated bogon isn't sending a random database
* into another configuration. This could happen on a bad configuration
* screwup. Thus, we only object if we're sure we know who the sync site
* is, and it ain't the guy talking to us.
*/
offset = uvote_GetSyncSite();
tconn = rx_ConnectionOf(rxcall);
tpeer = rx_PeerOf(tconn);
otherHost = ubikGetPrimaryInterfaceAddr(rx_HostOf(tpeer));
if (offset && offset != otherHost) {
/* we *know* this is the wrong guy */
code = USYNC;
DBHOLD(dbase);
goto failed;
}
DBHOLD(dbase);
/* abort any active trans that may scribble over the database */
urecovery_AbortAll(dbase);
ubik_print("Ubik: Synchronize database with server %s\n",
afs_inet_ntoa_r(otherHost, hoststr));
offset = 0;
UBIK_VERSION_LOCK;
epoch = tversion.epoch = 0; /* start off by labelling in-transit db as invalid */
(*dbase->setlabel) (dbase, file, &tversion); /* setlabel does sync */
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.TMP",
ubik_dbase->pathName, (file<0)?"SYS":"",
(file<0)?-file:file);
fd = open(pbuffer, O_CREAT | O_RDWR | O_TRUNC, 0600);
if (fd < 0) {
code = errno;
goto failed_locked;
}
code = lseek(fd, HDRSIZE, 0);
if (code != HDRSIZE) {
close(fd);
goto failed_locked;
}
pass = 0;
memcpy(&ubik_dbase->version, &tversion, sizeof(struct ubik_version));
UBIK_VERSION_UNLOCK;
while (length > 0) {
tlen = (length > sizeof(tbuffer) ? sizeof(tbuffer) : length);
#if !defined(AFS_PTHREAD_ENV)
if (pass % 4 == 0)
IOMGR_Poll();
#endif
code = rx_Read(rxcall, tbuffer, tlen);
if (code != tlen) {
ubik_dprint("Rx-read length error=%d\n", code);
code = BULK_ERROR;
close(fd);
goto failed;
}
code = write(fd, tbuffer, tlen);
pass++;
if (code != tlen) {
ubik_dprint("write failed error=%d\n", code);
code = UIOERROR;
close(fd);
goto failed;
}
offset += tlen;
length -= tlen;
}
code = close(fd);
if (code)
goto failed;
/* sync data first, then write label and resync (resync done by setlabel call).
* This way, good label is only on good database. */
snprintf(tbuffer, sizeof(tbuffer), "%s.DB%s%d",
ubik_dbase->pathName, (file<0)?"SYS":"", (file<0)?-file:file);
#ifdef AFS_NT40_ENV
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.OLD",
ubik_dbase->pathName, (file<0)?"SYS":"", (file<0)?-file:file);
code = unlink(pbuffer);
if (!code)
code = rename(tbuffer, pbuffer);
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.TMP",
ubik_dbase->pathName, (file<0)?"SYS":"", (file<0)?-file:file);
#endif
if (!code)
code = rename(pbuffer, tbuffer);
UBIK_VERSION_LOCK;
if (!code) {
(*ubik_dbase->open) (ubik_dbase, file);
code = (*ubik_dbase->setlabel) (dbase, file, avers);
}
#ifdef AFS_NT40_ENV
snprintf(pbuffer, sizeof(pbuffer), "%s.DB%s%d.OLD",
ubik_dbase->pathName, (file<0)?"SYS":"", (file<0)?-file:file);
unlink(pbuffer);
#endif
memcpy(&ubik_dbase->version, avers, sizeof(struct ubik_version));
udisk_Invalidate(dbase, file); /* new dbase, flush disk buffers */
#ifdef AFS_PTHREAD_ENV
assert(pthread_cond_broadcast(&dbase->version_cond) == 0);
#else
LWP_NoYieldSignal(&dbase->version);
#endif
failed_locked:
UBIK_VERSION_UNLOCK;
failed:
if (code) {
unlink(pbuffer);
/* Failed to sync. Allow reads again for now. */
if (dbase != NULL) {
UBIK_VERSION_LOCK;
tversion.epoch = epoch;
(*dbase->setlabel) (dbase, file, &tversion);
UBIK_VERSION_UNLOCK;
}
ubik_print
("Ubik: Synchronize database with server %s failed (error = %d)\n",
afs_inet_ntoa_r(otherHost, hoststr), code);
} else {
ubik_print("Ubik: Synchronize database completed\n");
}
DBRELE(dbase);
return code;
}
