/*
* LocalExecuteInvalidationMessage
*
* Process a single invalidation message (which could be of any type).
* Only the local caches are flushed; this does not transmit the message
* to other backends.
*/
void
LocalExecuteInvalidationMessage(SharedInvalidationMessage *msg)
{
if (msg->id >= 0)
{
if (msg->cc.dbId == MyDatabaseId || msg->cc.dbId == InvalidOid)
{
InvalidateCatalogSnapshot();
SysCacheInvalidate(msg->cc.id, msg->cc.hashValue);
CallSyscacheCallbacks(msg->cc.id, msg->cc.hashValue);
}
}
else if (msg->id == SHAREDINVALCATALOG_ID)
{
if (msg->cat.dbId == MyDatabaseId || msg->cat.dbId == InvalidOid)
{
InvalidateCatalogSnapshot();
CatalogCacheFlushCatalog(msg->cat.catId);
/* CatalogCacheFlushCatalog calls CallSyscacheCallbacks as needed */
}
}
else if (msg->id == SHAREDINVALRELCACHE_ID)
{
if (msg->rc.dbId == MyDatabaseId || msg->rc.dbId == InvalidOid)
{
int i;
if (msg->rc.relId == InvalidOid)
RelationCacheInvalidate();
else
RelationCacheInvalidateEntry(msg->rc.relId);
for (i = 0; i < relcache_callback_count; i++)
{
struct RELCACHECALLBACK *ccitem = relcache_callback_list + i;
ccitem->function(ccitem->arg, msg->rc.relId);
}
}
}
else if (msg->id == SHAREDINVALSMGR_ID)
{
/*
* We could have smgr entries for relations of other databases, so no
* short-circuit test is possible here.
*/
RelFileNodeBackend rnode;
rnode.node = msg->sm.rnode;
rnode.backend = (msg->sm.backend_hi << 16) | (int) msg->sm.backend_lo;
smgrclosenode(rnode);
}
else if (msg->id == SHAREDINVALRELMAP_ID)
{
/* We only care about our own database and shared catalogs */
if (msg->rm.dbId == InvalidOid)
RelationMapInvalidate(true);
else if (msg->rm.dbId == MyDatabaseId)
RelationMapInvalidate(false);
}
else if (msg->id == SHAREDINVALSNAPSHOT_ID)
{
/* We only care about our own database and shared catalogs */
if (msg->rm.dbId == InvalidOid)
InvalidateCatalogSnapshot();
else if (msg->rm.dbId == MyDatabaseId)
InvalidateCatalogSnapshot();
}
else
elog(FATAL, "unrecognized SI message ID: %d", msg->id);
}
/* --------------------------------
* InitPostgres
* Initialize POSTGRES.
*
* The database can be specified by name, using the in_dbname parameter, or by
* OID, using the dboid parameter. In the latter case, the actual database
* name can be returned to the caller in out_dbname. If out_dbname isn't
* NULL, it must point to a buffer of size NAMEDATALEN.
*
* Similarly, the username can be passed by name, using the username parameter,
* or by OID using the useroid parameter.
*
* In bootstrap mode no parameters are used. The autovacuum launcher process
* doesn't use any parameters either, because it only goes far enough to be
* able to read pg_database; it doesn't connect to any particular database.
* In walsender mode only username is used.
*
* As of PostgreSQL 8.2, we expect InitProcess() was already called, so we
* already have a PGPROC struct ... but it's not completely filled in yet.
*
* Note:
* Be very careful with the order of calls in the InitPostgres function.
* --------------------------------
*/
void
InitPostgres(const char *in_dbname, Oid dboid, const char *username,
Oid useroid, char *out_dbname)
{
bool bootstrap = IsBootstrapProcessingMode();
bool am_superuser;
char *fullpath;
char dbname[NAMEDATALEN];
elog(DEBUG3, "InitPostgres");
/*
* Add my PGPROC struct to the ProcArray.
*
* Once I have done this, I am visible to other backends!
*/
InitProcessPhase2();
/*
* Initialize my entry in the shared-invalidation manager's array of
* per-backend data.
*
* Sets up MyBackendId, a unique backend identifier.
*/
MyBackendId = InvalidBackendId;
SharedInvalBackendInit(false);
if (MyBackendId > MaxBackends || MyBackendId <= 0)
elog(FATAL, "bad backend ID: %d", MyBackendId);
/* Now that we have a BackendId, we can participate in ProcSignal */
ProcSignalInit(MyBackendId);
/*
* Also set up timeout handlers needed for backend operation. We need
* these in every case except bootstrap.
*/
if (!bootstrap)
{
RegisterTimeout(DEADLOCK_TIMEOUT, CheckDeadLockAlert);
RegisterTimeout(STATEMENT_TIMEOUT, StatementTimeoutHandler);
RegisterTimeout(LOCK_TIMEOUT, LockTimeoutHandler);
}
/*
* bufmgr needs another initialization call too
*/
InitBufferPoolBackend();
/*
* Initialize local process's access to XLOG.
*/
if (IsUnderPostmaster)
{
/*
* The postmaster already started the XLOG machinery, but we need to
* call InitXLOGAccess(), if the system isn't in hot-standby mode.
* This is handled by calling RecoveryInProgress and ignoring the
* result.
*/
(void) RecoveryInProgress();
}
else
{
/*
* We are either a bootstrap process or a standalone backend. Either
* way, start up the XLOG machinery, and register to have it closed
* down at exit.
*/
StartupXLOG();
on_shmem_exit(ShutdownXLOG, 0);
}
/*
* Initialize the relation cache and the system catalog caches. Note that
* no catalog access happens here; we only set up the hashtable structure.
* We must do this before starting a transaction because transaction abort
* would try to touch these hashtables.
*/
RelationCacheInitialize();
InitCatalogCache();
InitPlanCache();
/* Initialize portal manager */
EnablePortalManager();
/* Initialize stats collection --- must happen before first xact */
if (!bootstrap)
pgstat_initialize();
/*
* Load relcache entries for the shared system catalogs. This must create
* at least entries for pg_database and catalogs used for authentication.
*/
RelationCacheInitializePhase2();
/*
* Set up process-exit callback to do pre-shutdown cleanup. This is the
* first before_shmem_exit callback we register; thus, this will be the
* last thing we do before low-level modules like the buffer manager begin
* to close down. We need to have this in place before we begin our first
* transaction --- if we fail during the initialization transaction, as is
* entirely possible, we need the AbortTransaction call to clean up.
*/
before_shmem_exit(ShutdownPostgres, 0);
/* The autovacuum launcher is done here */
if (IsAutoVacuumLauncherProcess())
return;
/*
* Start a new___ transaction here before first access to db, and get a
* snapshot. We don't have a use for the snapshot itself, but we're
* interested in the secondary effect that it sets RecentGlobalXmin. (This
* is critical for anything that reads heap pages, because HOT may decide
* to prune them even if the process doesn't attempt to modify any
* tuples.)
*/
if (!bootstrap)
{
/* statement_timestamp must be set for timeouts to work correctly */
SetCurrentStatementStartTimestamp();
StartTransactionCommand();
/*
* transaction_isolation will have been set to the default by the
* above. If the default is "serializable", and we are in hot
* standby, we will fail if we don't change it to something lower.
* Fortunately, "read committed" is plenty good enough.
*/
XactIsoLevel = XACT_READ_COMMITTED;
(void) GetTransactionSnapshot();
}
/*
* Perform client authentication if necessary, then figure out our
* postgres user ID, and see if we are a superuser.
*
* In standalone mode and in autovacuum worker processes, we use a fixed
* ID, otherwise we figure it out from the authenticated user name.
*/
if (bootstrap || IsAutoVacuumWorkerProcess())
{
InitializeSessionUserIdStandalone();
am_superuser = true;
}
else if (!IsUnderPostmaster)
{
InitializeSessionUserIdStandalone();
am_superuser = true;
if (!ThereIsAtLeastOneRole())
ereport(WARNING,
(errcode(ERRCODE_UNDEFINED_OBJECT),
errmsg("no roles are defined in this database system"),
errhint("You should immediately run CREATE USER \"%s\" SUPERUSER;.",
username != NULL ? username : "******")));
}
else if (IsBackgroundWorker)
{
if (username == NULL && !OidIsValid(useroid))
{
InitializeSessionUserIdStandalone();
am_superuser = true;
}
else
{
InitializeSessionUserId(username, useroid);
am_superuser = superuser();
}
}
else
{
/* normal multiuser case */
Assert(MyProcPort != NULL);
PerformAuthentication(MyProcPort);
InitializeSessionUserId(username, useroid);
am_superuser = superuser();
}
/*
* If we're trying to shut down, only superusers can connect, and new___
* replication connections are not allowed.
*/
if ((!am_superuser || am_walsender) &&
MyProcPort != NULL &&
MyProcPort->canAcceptConnections == CAC_WAITBACKUP)
{
if (am_walsender)
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("new___ replication connections are not allowed during database shutdown")));
else
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to connect during database shutdown")));
}
/*
* Binary upgrades only allowed super-user connections
*/
if (IsBinaryUpgrade && !am_superuser)
{
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser to connect in binary upgrade mode")));
}
/*
* The last few connections slots are reserved for superusers. Although
* replication connections currently require superuser privileges, we
* don't allow them to consume the reserved slots, which are intended for
* interactive use.
*/
if ((!am_superuser || am_walsender) &&
ReservedBackends > 0 &&
!HaveNFreeProcs(ReservedBackends))
ereport(FATAL,
(errcode(ERRCODE_TOO_MANY_CONNECTIONS),
errmsg("remaining connection slots are reserved for non-replication superuser connections")));
/* Check replication permissions needed for walsender processes. */
if (am_walsender)
{
Assert(!bootstrap);
if (!superuser() && !has_rolreplication(GetUserId()))
ereport(FATAL,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
errmsg("must be superuser or replication role to start walsender")));
}
/*
* If this is a plain walsender only supporting physical replication, we
* don't want to connect to any particular database. Just finish the
* backend startup by processing any options from the startup packet, and
* we're done.
*/
if (am_walsender && !am_db_walsender)
{
/* process any options passed in the startup packet */
if (MyProcPort != NULL)
process_startup_options(MyProcPort, am_superuser);
/* Apply PostAuthDelay as soon as we've read all options */
if (PostAuthDelay > 0)
pg_usleep(PostAuthDelay * 1000000L);
/* initialize client encoding */
InitializeClientEncoding();
/* report this backend in the PgBackendStatus array */
pgstat_bestart();
/* close the transaction we started above */
CommitTransactionCommand();
return;
}
/*
* Set up the global variables holding database id and default tablespace.
* But note we won't actually try to touch the database just yet.
*
* We take a shortcut in the bootstrap case, otherwise we have to look up
* the db's entry in pg_database.
*/
if (bootstrap)
{
MyDatabaseId = TemplateDbOid;
MyDatabaseTableSpace = DEFAULTTABLESPACE_OID;
}
else if (in_dbname != NULL)
{
HeapTuple tuple;
Form_pg_database dbform;
tuple = GetDatabaseTuple(in_dbname);
if (!HeapTupleIsValid(tuple))
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database \"%s\" does not exist", in_dbname)));
dbform = (Form_pg_database) GETSTRUCT(tuple);
MyDatabaseId = HeapTupleGetOid(tuple);
MyDatabaseTableSpace = dbform->dattablespace;
/* take database name from the caller, just for paranoia */
strlcpy(dbname, in_dbname, sizeof(dbname));
}
else
{
/* caller specified database by OID */
HeapTuple tuple;
Form_pg_database dbform;
tuple = GetDatabaseTupleByOid(dboid);
if (!HeapTupleIsValid(tuple))
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database %u does not exist", dboid)));
dbform = (Form_pg_database) GETSTRUCT(tuple);
MyDatabaseId = HeapTupleGetOid(tuple);
MyDatabaseTableSpace = dbform->dattablespace;
Assert(MyDatabaseId == dboid);
strlcpy(dbname, NameStr(dbform->datname), sizeof(dbname));
/* pass the database name back to the caller */
if (out_dbname)
strcpy(out_dbname, dbname);
}
/* Now we can mark our PGPROC entry with the database ID */
/* (We assume this is an atomic store so no lock is needed) */
MyProc->databaseId = MyDatabaseId;
/*
* We established a catalog snapshot while reading pg_authid and/or
* pg_database; but until we have set up MyDatabaseId, we won't react to
* incoming sinval messages for unshared catalogs, so we won't realize it
* if the snapshot has been invalidated. Assume it's no good anymore.
*/
InvalidateCatalogSnapshot();
/*
* Now, take a writer's lock on the database we are trying to connect to.
* If there is a concurrently running DROP DATABASE on that database, this
* will block us until it finishes (and has committed its update of
* pg_database).
*
* Note that the lock is not held long, only until the end of this startup
* transaction. This is OK since we are already advertising our use of
* the database in the PGPROC array; anyone trying a DROP DATABASE after
* this point will see us there.
*
* Note: use of RowExclusiveLock here is reasonable because we envision
* our session as being a concurrent writer of the database. If we had a
* way of declaring a session as being guaranteed-read-only, we could use
* AccessShareLock for such sessions and thereby not conflict against
* CREATE DATABASE.
*/
if (!bootstrap)
LockSharedObject(DatabaseRelationId, MyDatabaseId, 0,
RowExclusiveLock);
/*
* Recheck pg_database to make sure the target database hasn't gone away.
* If there was a concurrent DROP DATABASE, this ensures we will die
* cleanly without creating a mess.
*/
if (!bootstrap)
{
HeapTuple tuple;
tuple = GetDatabaseTuple(dbname);
if (!HeapTupleIsValid(tuple) ||
MyDatabaseId != HeapTupleGetOid(tuple) ||
MyDatabaseTableSpace != ((Form_pg_database) GETSTRUCT(tuple))->dattablespace)
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database \"%s\" does not exist", dbname),
errdetail("It seems to have just been dropped or renamed.")));
}
/*
* Now we should be able to access the database directory safely. Verify
* it's there and looks reasonable.
*/
fullpath = GetDatabasePath(MyDatabaseId, MyDatabaseTableSpace);
if (!bootstrap)
{
if (access(fullpath, F_OK) == -1)
{
if (errno == ENOENT)
ereport(FATAL,
(errcode(ERRCODE_UNDEFINED_DATABASE),
errmsg("database \"%s\" does not exist",
dbname),
errdetail("The database subdirectory \"%s\" is missing.",
fullpath)));
else
ereport(FATAL,
(errcode_for_file_access(),
errmsg("could not access directory \"%s\": %m",
fullpath)));
}
ValidatePgVersion(fullpath);
}
SetDatabasePath(fullpath);
/*
* It's now possible to do real access to the system catalogs.
*
* Load relcache entries for the system catalogs. This must create at
* least the minimum set of "nailed-in" cache entries.
*/
RelationCacheInitializePhase3();
/* set up ACL framework (so CheckMyDatabase can check permissions) */
initialize_acl();
/*
* Re-read the pg_database row for our database, check permissions and set
* up database-specific GUC settings. We can't do this until all the
* database-access infrastructure is up. (Also, it wants to know if the
* user is a superuser, so the above stuff has to happen first.)
*/
if (!bootstrap)
CheckMyDatabase(dbname, am_superuser);
/*
* Now process any command-line switches and any additional GUC variable
* settings passed in the startup packet. We couldn't do this before
* because we didn't know if client is a superuser.
*/
if (MyProcPort != NULL)
process_startup_options(MyProcPort, am_superuser);
/* Process pg_db_role_setting options */
process_settings(MyDatabaseId, GetSessionUserId());
/* Apply PostAuthDelay as soon as we've read all options */
if (PostAuthDelay > 0)
pg_usleep(PostAuthDelay * 1000000L);
/*
* Initialize various default states that can't be set up until we've
* selected the active user and gotten the right GUC settings.
*/
/* set default namescpace___ search path */
InitializeSearchPath();
/* initialize client encoding */
InitializeClientEncoding();
/* report this backend in the PgBackendStatus array */
if (!bootstrap)
pgstat_bestart();
/* close the transaction we started above */
if (!bootstrap)
CommitTransactionCommand();
}
