database/postgres
database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-05-06 19:59:18 +03:00
Code
postgres/src/backend/utils/init/postinit.c
Bruce Momjian ed7a17dca0 Remove unneeded stat calls.
1997-08-27 03:48:50 +00:00

654 lines
21 KiB
C
Raw Blame History

/*-------------------------------------------------------------------------
*
* postinit.c--
* postgres initialization utilities
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/init/postinit.c,v 1.12 1997/08/27 03:48:39 momjian Exp $
*
* NOTES
* InitPostgres() is the function called from PostgresMain
* which does all non-trival initialization, mainly by calling
* all the other initialization functions. InitPostgres()
* is only used within the "postgres" backend and so that routine
* is in tcop/postgres.c InitPostgres() is needed in cinterface.a
* because things like the bootstrap backend program need it. Hence
* you find that in this file...
*
* If you feel the need to add more initialization code, it should be
* done in InitPostgres() or someplace lower. Do not start
* putting stuff in PostgresMain - if you do then someone
* will have to clean it up later, and it's not going to be me!
* -cim 10/3/90
*
*-------------------------------------------------------------------------
*/
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/file.h>
#include <sys/types.h>
#include <math.h>
#include <unistd.h>
#include "postgres.h"
#include "version.h"
#include <storage/ipc.h>
#include <storage/backendid.h>
#include <storage/buf_internals.h>
#include <storage/smgr.h>
#include <storage/proc.h>
#include <utils/relcache.h>
#include "access/heapam.h"
#include "access/xact.h"
#include "storage/bufmgr.h"
#include "access/transam.h" /* XXX dependency problem */
#include "utils/tqual.h"
#include "utils/syscache.h"
#include "storage/bufpage.h" /* for page layout, for InitMyDatabaseId() */
#include "storage/sinval.h"
#include "storage/sinvaladt.h"
#include "storage/lmgr.h"
#include "miscadmin.h" /* for global decls */
#include "utils/portal.h" /* for EnablePortalManager, etc. */
#include "utils/exc.h" /* for EnableExceptionHandling, etc. */
#include "fmgr.h" /* for EnableDynamicFunctionManager, etc. */
#include "utils/elog.h"
#include "utils/palloc.h"
#include "utils/mcxt.h" /* for EnableMemoryContext, etc. */
#include "catalog/catname.h"
#include "catalog/pg_database.h"
#include "port-protos.h"
#include "libpq/libpq-be.h"
static void InitCommunication(void);
static void InitMyDatabaseId(void);
static void InitStdio(void);
static void InitUserid(void);
static IPCKey PostgresIpcKey;
/* ----------------------------------------------------------------
* InitPostgres support
* ----------------------------------------------------------------
*/
/* --------------------------------
* InitMyDatabaseId() -- Find and record the OID of the database we are
* to open.
*
* The database's oid forms half of the unique key for the system
* caches and lock tables. We therefore want it initialized before
* we open any relations, since opening relations puts things in the
* cache. To get around this problem, this code opens and scans the
* pg_database relation by hand.
*
* This algorithm relies on the fact that first attribute in the
* pg_database relation schema is the database name. It also knows
* about the internal format of tuples on disk and the length of
* the datname attribute. It knows the location of the pg_database
* file.
*
* This code is called from InitDatabase(), after we chdir() to the
* database directory but before we open any relations.
* --------------------------------
*/
static void
InitMyDatabaseId()
{
int dbfd;
int fileflags;
int nbytes;
int max, i;
HeapTuple tup;
Page pg;
PageHeader ph;
char *dbfname;
Form_pg_database tup_db;
/*
* At bootstrap time, we don't need to check the oid of the database
* in use, since we're not using shared memory. This is lucky, since
* the database may not be in the tables yet.
*/
if (IsBootstrapProcessingMode()) {
LockDisable(true);
return;
}
dbfname = (char *) palloc(strlen(DataDir) + strlen("pg_database") + 2);
sprintf(dbfname, "%s%cpg_database", DataDir, SEP_CHAR);
fileflags = O_RDONLY;
if ((dbfd = open(dbfname, O_RDONLY, 0)) < 0)
elog(FATAL, "Cannot open %s", dbfname);
pfree(dbfname);
/* ----------------
* read and examine every page in pg_database
*
* Raw I/O! Read those tuples the hard way! Yow!
*
* Why don't we use the access methods or move this code
* someplace else? This is really pg_database schema dependent
* code. Perhaps it should go in lib/catalog/pg_database?
* -cim 10/3/90
*
* mao replies 4 apr 91: yeah, maybe this should be moved to
* lib/catalog. however, we CANNOT use the access methods since
* those use the buffer cache, which uses the relation cache, which
* requires that the dbid be set, which is what we're trying to do
* here.
* ----------------
*/
pg = (Page) palloc(BLCKSZ);
ph = (PageHeader) pg;
while ((nbytes = read(dbfd, pg, BLCKSZ)) == BLCKSZ) {
max = PageGetMaxOffsetNumber(pg);
/* look at each tuple on the page */
for (i = 0; i <= max; i++) {
int offset;
/* if it's a freed tuple, ignore it */
if (!(ph->pd_linp[i].lp_flags & LP_USED))
continue;
/* get a pointer to the tuple itself */
offset = (int) ph->pd_linp[i].lp_off;
tup = (HeapTuple) (((char *) pg) + offset);
/*
* if the tuple has been deleted (the database was destroyed),
* skip this tuple. XXX warning, will robinson: violation of
* transaction semantics happens right here. we should check
* to be sure that the xact that deleted this tuple actually
* committed. only way to do this at init time is to paw over
* the log relation by hand, too. let's be optimistic.
*
* XXX This is an evil type cast. tup->t_xmax is char[5] while
* TransactionId is struct * { char data[5] }. It works but
* if data is ever moved and no longer the first field this
* will be broken!! -mer 11 Nov 1991.
*/
if (TransactionIdIsValid((TransactionId)tup->t_xmax))
continue;
/*
* Okay, see if this is the one we want.
* XXX 1 july 91: mao and mer discover that tuples now squash
* t_bits. Why is this?
*
* 24 july 92: mer realizes that the t_bits field is only
* used in the event of null values. If no
* fields are null we reduce the header size
* by doing the squash. t_hoff tells you exactly
* how big the header actually is. use the PC
* means of getting at sys cat attrs.
*/
tup_db = (Form_pg_database)GETSTRUCT(tup);
if (strncmp(GetDatabaseName(),
&(tup_db->datname.data[0]),
16) == 0)
{
MyDatabaseId = tup->t_oid;
goto done;
}
}
}
done:
close(dbfd);
pfree(pg);
if (!OidIsValid(MyDatabaseId))
elog(FATAL,
"Database %s does not exist in %s",
GetDatabaseName(),
DatabaseRelationName);
}
/*
* DoChdirAndInitDatabaseNameAndPath --
* Set current directory to the database directory for the database
* named <name>.
* Also set global variables DatabasePath and DatabaseName to those
* values. Also check for proper version of database system and
* database. Exit program via elog() if anything doesn't check out.
*
* Arguments:
* Path and name are invalid if it invalid as a string.
* Path is "badly formated" if it is not a string containing a path
* to a writable directory.
* Name is "badly formated" if it contains more than 16 characters or if
* it is a bad file name (e.g., it contains a '/' or an 8-bit character).
*
* Exceptions:
* BadState if called more than once.
* BadArg if both path and name are "badly formated" or invalid.
* BadArg if path and name are both "inconsistent" and valid.
*
* This routine is inappropriate in bootstrap mode, since the directories
* and version files need not exist yet if we're in bootstrap mode.
*/
static void
DoChdirAndInitDatabaseNameAndPath(char *name) {
char *reason;
/* Failure reason returned by some function. NULL if no failure */
int fd;
char errormsg[1000];
if ((fd = open(DataDir, O_RDONLY,0)) == -1)
sprintf(errormsg, "Database system does not exist. "
"PGDATA directory '%s' not found. Normally, you "
"create a database system by running initdb.",
DataDir);
else {
char myPath[MAXPGPATH]; /* DatabasePath points here! */
close(fd);
if (strlen(DataDir) + strlen(name) + 10 > sizeof(myPath))
sprintf(errormsg, "Internal error in postinit.c: database "
"pathname exceeds maximum allowable length.");
else {
sprintf(myPath, "%s/base/%s", DataDir, name);
if ((fd = open(myPath, O_RDONLY,0)) == -1)
sprintf(errormsg,
"Database '%s' does not exist. "
"(We know this because the directory '%s' "
"does not exist). You can create a database "
"with the SQL command CREATE DATABASE. To see "
"what databases exist, look at the subdirectories "
"of '%s/base/'.",
name, myPath, DataDir);
else {
close(fd);
ValidatePgVersion(DataDir, &reason);
if (reason != NULL)
sprintf(errormsg,
"InitPostgres could not validate that the database "
"system version is compatible with this level of "
"Postgres. You may need to run initdb to create "
"a new database system. %s",
reason);
else {
ValidatePgVersion(myPath, &reason);
if (reason != NULL)
sprintf(errormsg,
"InitPostgres could not validate that the "
"database version is compatible with this level "
"of Postgres, even though the database system "
"as a whole appears to be at a compatible level. "
"You may need to recreate the database with SQL "
"commands DROP DATABASE and CREATE DATABASE. "
"%s",
reason);
else {
/* The directories and PG_VERSION files are in order.*/
int rc; /* return code from some function we call */
SetDatabasePath(myPath);
SetDatabaseName(name);
rc = chdir(myPath);
if (rc < 0)
sprintf(errormsg,
"InitPostgres unable to change "
"current directory to '%s', errno = %s (%d).",
myPath, strerror(errno), errno);
else errormsg[0] = '\0';
}
}
}
}
}
if (errormsg[0] != '\0')
elog(FATAL, errormsg);
/* Above does not return */
}
/* --------------------------------
* InitUserid
*
* initializes crap associated with the user id.
* --------------------------------
*/
static void
InitUserid()
{
setuid(geteuid());
SetUserId();
}
/* --------------------------------
* InitCommunication
*
* This routine initializes stuff needed for ipc, locking, etc.
* it should be called something more informative.
*
* Note:
* This does not set MyBackendId. MyBackendTag is set, however.
* --------------------------------
*/
static void
InitCommunication()
{
char *postid;
char *postport;
IPCKey key = 0;
/* ----------------
* try and get the backend tag from POSTID
* ----------------
*/
MyBackendId = -1;
postid = getenv("POSTID");
if (!PointerIsValid(postid)) {
MyBackendTag = -1;
} else {
MyBackendTag = atoi(postid);
Assert(MyBackendTag >= 0);
}
/* ----------------
* try and get the ipc key from POSTPORT
* ----------------
*/
postport = getenv("POSTPORT");
if (PointerIsValid(postport)) {
SystemPortAddress address = atoi(postport);
if (address == 0)
elog(FATAL, "InitCommunication: invalid POSTPORT");
if (MyBackendTag == -1)
elog(FATAL, "InitCommunication: missing POSTID");
key = SystemPortAddressCreateIPCKey(address);
/*
* Enable this if you are trying to force the backend to run as if it
* is running under the postmaster.
*
* This goto forces Postgres to attach to shared memory instead of
* using malloc'ed memory (which is the normal behavior if run
* directly).
*
* To enable emulation, run the following shell commands (in addition
* to enabling this goto)
*
* % setenv POSTID 1
* % setenv POSTPORT 4321
* % postmaster &
* % kill -9 %1
*
* Upon doing this, Postmaster will have allocated the shared memory
* resources that Postgres will attach to if you enable
* EMULATE_UNDER_POSTMASTER.
*
* This comment may well age with time - it is current as of
* 8 January 1990
*
* Greg
*/
#ifdef EMULATE_UNDER_POSTMASTER
goto forcesharedmemory;
#endif
} else if (IsUnderPostmaster) {
elog(FATAL,
"InitCommunication: under postmaster and POSTPORT not set");
} else {
/* ----------------
* assume we're running a postgres backend by itself with
* no front end or postmaster.
* ----------------
*/
if (MyBackendTag == -1) {
MyBackendTag = 1;
}
key = PrivateIPCKey;
}
/* ----------------
* initialize shared memory and semaphores appropriately.
* ----------------
*/
#ifdef EMULATE_UNDER_POSTMASTER
forcesharedmemory:
#endif
PostgresIpcKey = key;
AttachSharedMemoryAndSemaphores(key);
}
/* --------------------------------
* InitStdio
*
* this routine consists of a bunch of code fragments
* that used to be randomly scattered through cinit().
* they all seem to do stuff associated with io.
* --------------------------------
*/
static void
InitStdio()
{
DebugFileOpen();
}
/* --------------------------------
* InitPostgres --
* Initialize POSTGRES.
*
* Note:
* Be very careful with the order of calls in the InitPostgres function.
* --------------------------------
*/
bool PostgresIsInitialized = false;
extern int NBuffers;
/*
* this global is used by wei for testing his code, but must be declared
* here rather than in postgres.c so that it's defined for cinterface.a
* applications.
*/
/*int testFlag = 0;*/
int lockingOff = 0;
/*
*/
void
InitPostgres(char *name) /* database name */
{
bool bootstrap; /* true if BootstrapProcessing */
/* ----------------
* see if we're running in BootstrapProcessing mode
* ----------------
*/
bootstrap = IsBootstrapProcessingMode();
/* ----------------
* turn on the exception handler. Note: we cannot use elog, Assert,
* AssertState, etc. until after exception handling is on.
* ----------------
*/
EnableExceptionHandling(true);
/* ----------------
* A stupid check to make sure we don't call this more than once.
* But things like ReinitPostgres() get around this by just diddling
* the PostgresIsInitialized flag.
* ----------------
*/
AssertState(!PostgresIsInitialized);
/* ----------------
* Memory system initialization.
* (we may call palloc after EnableMemoryContext())
*
* Note EnableMemoryContext() must happen before EnablePortalManager().
* ----------------
*/
EnableMemoryContext(true); /* initializes the "top context" */
EnablePortalManager(true); /* memory for portal/transaction stuff */
/* ----------------
* initialize the backend local portal stack used by
* internal PQ function calls. see src/lib/libpq/be-dumpdata.c
* This is different from the "portal manager" so this goes here.
* -cim 2/12/91
* ----------------
*/
be_portalinit();
/* ----------------
* attach to shared memory and semaphores, and initialize our
* input/output/debugging file descriptors.
* ----------------
*/
InitCommunication();
InitStdio();
/*
* initialize the local buffer manager
*/
InitLocalBuffer();
if (!TransactionFlushEnabled())
on_exitpg(FlushBufferPool, (caddr_t) NULL);
if (bootstrap) {
SetDatabasePath(".");
SetDatabaseName(name);
} else {
DoChdirAndInitDatabaseNameAndPath(name);
}
/* ********************************
* code after this point assumes we are in the proper directory!
* ********************************
*/
/* ----------------
* initialize the database id used for system caches and lock tables
* ----------------
*/
InitMyDatabaseId();
smgrinit();
/* ----------------
* initialize the transaction system and the relation descriptor
* cache. Note we have to make certain the lock manager is off while
* we do this.
* ----------------
*/
AmiTransactionOverride(IsBootstrapProcessingMode());
LockDisable(true);
/*
* Part of the initialization processing done here sets a read
* lock on pg_log. Since locking is disabled the set doesn't have
* intended effect of locking out writers, but this is ok, since
* we only lock it to examine AMI transaction status, and this is
* never written after initdb is done. -mer 15 June 1992
*/
RelationInitialize(); /* pre-allocated reldescs created here */
InitializeTransactionSystem(); /* pg_log,etc init/crash recovery here */
LockDisable(false);
/* ----------------
* anyone knows what this does? something having to do with
* system catalog cache invalidation in the case of multiple
* backends, I think -cim 10/3/90
* Sets up MyBackendId a unique backend identifier.
* ----------------
*/
InitSharedInvalidationState();
/* ----------------
* Set up a per backend process in shared memory. Must be done after
* InitSharedInvalidationState() as it relies on MyBackendId being
* initialized already. XXX -mer 11 Aug 1991
* ----------------
*/
InitProcess(PostgresIpcKey);
if (MyBackendId > MaxBackendId || MyBackendId <= 0) {
elog(FATAL, "cinit2: bad backend id %d (%d)",
MyBackendTag,
MyBackendId);
}
/* ----------------
* initialize the access methods.
* ----------------
*/
initam();
/* ----------------
* initialize all the system catalog caches.
* ----------------
*/
zerocaches();
InitCatalogCache();
/* ----------------
* set ourselves to the proper user id and figure out our postgres
* user id. If we ever add security so that we check for valid
* postgres users, we might do it here.
* ----------------
*/
InitUserid();
/* ----------------
* ok, all done, now let's make sure we don't do it again.
* ----------------
*/
PostgresIsInitialized = true;
/* on_exitpg(DestroyLocalRelList, (caddr_t) NULL); */
/* ----------------
* Done with "InitPostgres", now change to NormalProcessing unless
* we're in BootstrapProcessing mode.
* ----------------
*/
if (!bootstrap)
SetProcessingMode(NormalProcessing);
/* if (testFlag || lockingOff) */
if (lockingOff)
LockDisable(true);
}
View Git Blame Copy Permalink