/*------------------------------------------------------------------------- * * miscinit.c * miscellaneous initialization support stuff * * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * * * IDENTIFICATION * $PostgreSQL: pgsql/src/backend/utils/init/miscinit.c,v 1.175 2009/06/11 14:49:05 momjian Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_UTIME_H #include #endif #include "catalog/pg_authid.h" #include "mb/pg_wchar.h" #include "miscadmin.h" #include "postmaster/autovacuum.h" #include "storage/fd.h" #include "storage/ipc.h" #include "storage/pg_shmem.h" #include "storage/proc.h" #include "storage/procarray.h" #include "utils/builtins.h" #include "utils/guc.h" #include "utils/syscache.h" #define DIRECTORY_LOCK_FILE "postmaster.pid" ProcessingMode Mode = InitProcessing; /* Note: we rely on this to initialize as zeroes */ static char socketLockFile[MAXPGPATH]; /* ---------------------------------------------------------------- * ignoring system indexes support stuff * * NOTE: "ignoring system indexes" means we do not use the system indexes * for lookups (either in hardwired catalog accesses or in planner-generated * plans). We do, however, still update the indexes when a catalog * modification is made. * ---------------------------------------------------------------- */ bool IgnoreSystemIndexes = false; /* ---------------------------------------------------------------- * system index reindexing support * * When we are busy reindexing a system index, this code provides support * for preventing catalog lookups from using that index. * ---------------------------------------------------------------- */ static Oid currentlyReindexedHeap = InvalidOid; static Oid currentlyReindexedIndex = InvalidOid; /* * ReindexIsProcessingHeap * True if heap specified by OID is currently being reindexed. */ bool ReindexIsProcessingHeap(Oid heapOid) { return heapOid == currentlyReindexedHeap; } /* * ReindexIsProcessingIndex * True if index specified by OID is currently being reindexed. */ bool ReindexIsProcessingIndex(Oid indexOid) { return indexOid == currentlyReindexedIndex; } /* * SetReindexProcessing * Set flag that specified heap/index are being reindexed. */ void SetReindexProcessing(Oid heapOid, Oid indexOid) { Assert(OidIsValid(heapOid) && OidIsValid(indexOid)); /* Reindexing is not re-entrant. */ if (OidIsValid(currentlyReindexedIndex)) elog(ERROR, "cannot reindex while reindexing"); currentlyReindexedHeap = heapOid; currentlyReindexedIndex = indexOid; } /* * ResetReindexProcessing * Unset reindexing status. */ void ResetReindexProcessing(void) { currentlyReindexedHeap = InvalidOid; currentlyReindexedIndex = InvalidOid; } /* ---------------------------------------------------------------- * database path / name support stuff * ---------------------------------------------------------------- */ void SetDatabasePath(const char *path) { if (DatabasePath) { free(DatabasePath); DatabasePath = NULL; } /* use strdup since this is done before memory contexts are set up */ if (path) { DatabasePath = strdup(path); AssertState(DatabasePath); } } /* * Set data directory, but make sure it's an absolute path. Use this, * never set DataDir directly. */ void SetDataDir(const char *dir) { char *new; AssertArg(dir); /* If presented path is relative, convert to absolute */ new = make_absolute_path(dir); if (DataDir) free(DataDir); DataDir = new; } /* * Change working directory to DataDir. Most of the postmaster and backend * code assumes that we are in DataDir so it can use relative paths to access * stuff in and under the data directory. For convenience during path * setup, however, we don't force the chdir to occur during SetDataDir. */ void ChangeToDataDir(void) { AssertState(DataDir); if (chdir(DataDir) < 0) ereport(FATAL, (errcode_for_file_access(), errmsg("could not change directory to \"%s\": %m", DataDir))); } /* * If the given pathname isn't already absolute, make it so, interpreting * it relative to the current working directory. * * Also canonicalizes the path. The result is always a malloc'd copy. * * Note: interpretation of relative-path arguments during postmaster startup * should happen before doing ChangeToDataDir(), else the user will probably * not like the results. */ char * make_absolute_path(const char *path) { char *new; /* Returning null for null input is convenient for some callers */ if (path == NULL) return NULL; if (!is_absolute_path(path)) { char *buf; size_t buflen; buflen = MAXPGPATH; for (;;) { buf = malloc(buflen); if (!buf) ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); if (getcwd(buf, buflen)) break; else if (errno == ERANGE) { free(buf); buflen *= 2; continue; } else { free(buf); elog(FATAL, "could not get current working directory: %m"); } } new = malloc(strlen(buf) + strlen(path) + 2); if (!new) ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); sprintf(new, "%s/%s", buf, path); free(buf); } else { new = strdup(path); if (!new) ereport(FATAL, (errcode(ERRCODE_OUT_OF_MEMORY), errmsg("out of memory"))); } /* Make sure punctuation is canonical, too */ canonicalize_path(new); return new; } /* ---------------------------------------------------------------- * User ID state * * We have to track several different values associated with the concept * of "user ID". * * AuthenticatedUserId is determined at connection start and never changes. * * SessionUserId is initially the same as AuthenticatedUserId, but can be * changed by SET SESSION AUTHORIZATION (if AuthenticatedUserIsSuperuser). * This is the ID reported by the SESSION_USER SQL function. * * OuterUserId is the current user ID in effect at the "outer level" (outside * any transaction or function). This is initially the same as SessionUserId, * but can be changed by SET ROLE to any role that SessionUserId is a * member of. (XXX rename to something like CurrentRoleId?) * * CurrentUserId is the current effective user ID; this is the one to use * for all normal permissions-checking purposes. At outer level this will * be the same as OuterUserId, but it changes during calls to SECURITY * DEFINER functions, as well as locally in some specialized commands. * * SecurityDefinerContext is TRUE if we are within a SECURITY DEFINER function * or another context that temporarily changes CurrentUserId. * ---------------------------------------------------------------- */ static Oid AuthenticatedUserId = InvalidOid; static Oid SessionUserId = InvalidOid; static Oid OuterUserId = InvalidOid; static Oid CurrentUserId = InvalidOid; /* We also have to remember the superuser state of some of these levels */ static bool AuthenticatedUserIsSuperuser = false; static bool SessionUserIsSuperuser = false; static bool SecurityDefinerContext = false; /* We also remember if a SET ROLE is currently active */ static bool SetRoleIsActive = false; /* * GetUserId - get the current effective user ID. * * Note: there's no SetUserId() anymore; use SetUserIdAndContext(). */ Oid GetUserId(void) { AssertState(OidIsValid(CurrentUserId)); return CurrentUserId; } /* * GetOuterUserId/SetOuterUserId - get/set the outer-level user ID. */ Oid GetOuterUserId(void) { AssertState(OidIsValid(OuterUserId)); return OuterUserId; } static void SetOuterUserId(Oid userid) { AssertState(!SecurityDefinerContext); AssertArg(OidIsValid(userid)); OuterUserId = userid; /* We force the effective user ID to match, too */ CurrentUserId = userid; } /* * GetSessionUserId/SetSessionUserId - get/set the session user ID. */ Oid GetSessionUserId(void) { AssertState(OidIsValid(SessionUserId)); return SessionUserId; } static void SetSessionUserId(Oid userid, bool is_superuser) { AssertState(!SecurityDefinerContext); AssertArg(OidIsValid(userid)); SessionUserId = userid; SessionUserIsSuperuser = is_superuser; SetRoleIsActive = false; /* We force the effective user IDs to match, too */ OuterUserId = userid; CurrentUserId = userid; } /* * GetUserIdAndContext/SetUserIdAndContext - get/set the current user ID * and the SecurityDefinerContext flag. * * Unlike GetUserId, GetUserIdAndContext does *not* Assert that the current * value of CurrentUserId is valid; nor does SetUserIdAndContext require * the new value to be valid. In fact, these routines had better not * ever throw any kind of error. This is because they are used by * StartTransaction and AbortTransaction to save/restore the settings, * and during the first transaction within a backend, the value to be saved * and perhaps restored is indeed invalid. We have to be able to get * through AbortTransaction without asserting in case InitPostgres fails. */ void GetUserIdAndContext(Oid *userid, bool *sec_def_context) { *userid = CurrentUserId; *sec_def_context = SecurityDefinerContext; } void SetUserIdAndContext(Oid userid, bool sec_def_context) { CurrentUserId = userid; SecurityDefinerContext = sec_def_context; } /* * InSecurityDefinerContext - are we inside a SECURITY DEFINER context? */ bool InSecurityDefinerContext(void) { return SecurityDefinerContext; } /* * Initialize user identity during normal backend startup */ void InitializeSessionUserId(const char *rolename) { HeapTuple roleTup; Form_pg_authid rform; Datum datum; bool isnull; Oid roleid; /* * Don't do scans if we're bootstrapping, none of the system catalogs * exist yet, and they should be owned by postgres anyway. */ AssertState(!IsBootstrapProcessingMode()); /* call only once */ AssertState(!OidIsValid(AuthenticatedUserId)); roleTup = SearchSysCache(AUTHNAME, PointerGetDatum(rolename), 0, 0, 0); if (!HeapTupleIsValid(roleTup)) ereport(FATAL, (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION), errmsg("role \"%s\" does not exist", rolename))); rform = (Form_pg_authid) GETSTRUCT(roleTup); roleid = HeapTupleGetOid(roleTup); AuthenticatedUserId = roleid; AuthenticatedUserIsSuperuser = rform->rolsuper; /* This sets OuterUserId/CurrentUserId too */ SetSessionUserId(roleid, AuthenticatedUserIsSuperuser); /* Also mark our PGPROC entry with the authenticated user id */ /* (We assume this is an atomic store so no lock is needed) */ MyProc->roleId = roleid; /* * These next checks are not enforced when in standalone mode, so that * there is a way to recover from sillinesses like "UPDATE pg_authid SET * rolcanlogin = false;". * * We do not enforce them for the autovacuum process either. */ if (IsUnderPostmaster && !IsAutoVacuumWorkerProcess()) { /* * Is role allowed to login at all? */ if (!rform->rolcanlogin) ereport(FATAL, (errcode(ERRCODE_INVALID_AUTHORIZATION_SPECIFICATION), errmsg("role \"%s\" is not permitted to log in", rolename))); /* * Check connection limit for this role. * * There is a race condition here --- we create our PGPROC before * checking for other PGPROCs. If two backends did this at about the * same time, they might both think they were over the limit, while * ideally one should succeed and one fail. Getting that to work * exactly seems more trouble than it is worth, however; instead we * just document that the connection limit is approximate. */ if (rform->rolconnlimit >= 0 && !AuthenticatedUserIsSuperuser && CountUserBackends(roleid) > rform->rolconnlimit) ereport(FATAL, (errcode(ERRCODE_TOO_MANY_CONNECTIONS), errmsg("too many connections for role \"%s\"", rolename))); } /* Record username and superuser status as GUC settings too */ SetConfigOption("session_authorization", rolename, PGC_BACKEND, PGC_S_OVERRIDE); SetConfigOption("is_superuser", AuthenticatedUserIsSuperuser ? "on" : "off", PGC_INTERNAL, PGC_S_OVERRIDE); /* * Set up user-specific configuration variables. This is a good place to * do it so we don't have to read pg_authid twice during session startup. */ datum = SysCacheGetAttr(AUTHNAME, roleTup, Anum_pg_authid_rolconfig, &isnull); if (!isnull) { ArrayType *a = DatumGetArrayTypeP(datum); /* * We process all the options at SUSET level. We assume that the * right to insert an option into pg_authid was checked when it was * inserted. */ ProcessGUCArray(a, PGC_SUSET, PGC_S_USER, GUC_ACTION_SET); } ReleaseSysCache(roleTup); } /* * Initialize user identity during special backend startup */ void InitializeSessionUserIdStandalone(void) { /* This function should only be called in a single-user backend. */ AssertState(!IsUnderPostmaster || IsAutoVacuumWorkerProcess()); /* call only once */ AssertState(!OidIsValid(AuthenticatedUserId)); AuthenticatedUserId = BOOTSTRAP_SUPERUSERID; AuthenticatedUserIsSuperuser = true; SetSessionUserId(BOOTSTRAP_SUPERUSERID, true); } /* * Change session auth ID while running * * Only a superuser may set auth ID to something other than himself. Note * that in case of multiple SETs in a single session, the original userid's * superuserness is what matters. But we set the GUC variable is_superuser * to indicate whether the *current* session userid is a superuser. * * Note: this is not an especially clean place to do the permission check. * It's OK because the check does not require catalog access and can't * fail during an end-of-transaction GUC reversion, but we may someday * have to push it up into assign_session_authorization. */ void SetSessionAuthorization(Oid userid, bool is_superuser) { /* Must have authenticated already, else can't make permission check */ AssertState(OidIsValid(AuthenticatedUserId)); if (userid != AuthenticatedUserId && !AuthenticatedUserIsSuperuser) ereport(ERROR, (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE), errmsg("permission denied to set session authorization"))); SetSessionUserId(userid, is_superuser); SetConfigOption("is_superuser", is_superuser ? "on" : "off", PGC_INTERNAL, PGC_S_OVERRIDE); } /* * Report current role id * This follows the semantics of SET ROLE, ie return the outer-level ID * not the current effective ID, and return InvalidOid when the setting * is logically SET ROLE NONE. */ Oid GetCurrentRoleId(void) { if (SetRoleIsActive) return OuterUserId; else return InvalidOid; } /* * Change Role ID while running (SET ROLE) * * If roleid is InvalidOid, we are doing SET ROLE NONE: revert to the * session user authorization. In this case the is_superuser argument * is ignored. * * When roleid is not InvalidOid, the caller must have checked whether * the session user has permission to become that role. (We cannot check * here because this routine must be able to execute in a failed transaction * to restore a prior value of the ROLE GUC variable.) */ void SetCurrentRoleId(Oid roleid, bool is_superuser) { /* * Get correct info if it's SET ROLE NONE * * If SessionUserId hasn't been set yet, just do nothing --- the eventual * SetSessionUserId call will fix everything. This is needed since we * will get called during GUC initialization. */ if (!OidIsValid(roleid)) { if (!OidIsValid(SessionUserId)) return; roleid = SessionUserId; is_superuser = SessionUserIsSuperuser; SetRoleIsActive = false; } else SetRoleIsActive = true; SetOuterUserId(roleid); SetConfigOption("is_superuser", is_superuser ? "on" : "off", PGC_INTERNAL, PGC_S_OVERRIDE); } /* * Get user name from user oid */ char * GetUserNameFromId(Oid roleid) { HeapTuple tuple; char *result; tuple = SearchSysCache(AUTHOID, ObjectIdGetDatum(roleid), 0, 0, 0); if (!HeapTupleIsValid(tuple)) ereport(ERROR, (errcode(ERRCODE_UNDEFINED_OBJECT), errmsg("invalid role OID: %u", roleid))); result = pstrdup(NameStr(((Form_pg_authid) GETSTRUCT(tuple))->rolname)); ReleaseSysCache(tuple); return result; } /*------------------------------------------------------------------------- * Interlock-file support * * These routines are used to create both a data-directory lockfile * ($DATADIR/postmaster.pid) and a Unix-socket-file lockfile ($SOCKFILE.lock). * Both kinds of files contain the same info: * * Owning process' PID * Data directory path * * By convention, the owning process' PID is negated if it is a standalone * backend rather than a postmaster. This is just for informational purposes. * The path is also just for informational purposes (so that a socket lockfile * can be more easily traced to the associated postmaster). * * A data-directory lockfile can optionally contain a third line, containing * the key and ID for the shared memory block used by this postmaster. * * On successful lockfile creation, a proc_exit callback to remove the * lockfile is automatically created. *------------------------------------------------------------------------- */ /* * proc_exit callback to remove a lockfile. */ static void UnlinkLockFile(int status, Datum filename) { char *fname = (char *) DatumGetPointer(filename); if (fname != NULL) { if (unlink(fname) != 0) { /* Should we complain if the unlink fails? */ } free(fname); } } /* * Create a lockfile. * * filename is the name of the lockfile to create. * amPostmaster is used to determine how to encode the output PID. * isDDLock and refName are used to determine what error message to produce. */ static void CreateLockFile(const char *filename, bool amPostmaster, bool isDDLock, const char *refName) { int fd; char buffer[MAXPGPATH + 100]; int ntries; int len; int encoded_pid; pid_t other_pid; pid_t my_pid = getpid(); /* * We need a loop here because of race conditions. But don't loop forever * (for example, a non-writable $PGDATA directory might cause a failure * that won't go away). 100 tries seems like plenty. */ for (ntries = 0;; ntries++) { /* * Try to create the lock file --- O_EXCL makes this atomic. * * Think not to make the file protection weaker than 0600. See * comments below. */ fd = open(filename, O_RDWR | O_CREAT | O_EXCL, 0600); if (fd >= 0) break; /* Success; exit the retry loop */ /* * Couldn't create the pid file. Probably it already exists. */ if ((errno != EEXIST && errno != EACCES) || ntries > 100) ereport(FATAL, (errcode_for_file_access(), errmsg("could not create lock file \"%s\": %m", filename))); /* * Read the file to get the old owner's PID. Note race condition * here: file might have been deleted since we tried to create it. */ fd = open(filename, O_RDONLY, 0600); if (fd < 0) { if (errno == ENOENT) continue; /* race condition; try again */ ereport(FATAL, (errcode_for_file_access(), errmsg("could not open lock file \"%s\": %m", filename))); } if ((len = read(fd, buffer, sizeof(buffer) - 1)) < 0) ereport(FATAL, (errcode_for_file_access(), errmsg("could not read lock file \"%s\": %m", filename))); close(fd); buffer[len] = '\0'; encoded_pid = atoi(buffer); /* if pid < 0, the pid is for postgres, not postmaster */ other_pid = (pid_t) (encoded_pid < 0 ? -encoded_pid : encoded_pid); if (other_pid <= 0) elog(FATAL, "bogus data in lock file \"%s\": \"%s\"", filename, buffer); /* * Check to see if the other process still exists * * If the PID in the lockfile is our own PID or our parent's PID, then * the file must be stale (probably left over from a previous system * boot cycle). We need this test because of the likelihood that a * reboot will assign exactly the same PID as we had in the previous * reboot. Also, if there is just one more process launch in this * reboot than in the previous one, the lockfile might mention our * parent's PID. We can reject that since we'd never be launched * directly by a competing postmaster. We can't detect grandparent * processes unfortunately, but if the init script is written * carefully then all but the immediate parent shell will be * root-owned processes and so the kill test will fail with EPERM. * * We can treat the EPERM-error case as okay because that error * implies that the existing process has a different userid than we * do, which means it cannot be a competing postmaster. A postmaster * cannot successfully attach to a data directory owned by a userid * other than its own. (This is now checked directly in * checkDataDir(), but has been true for a long time because of the * restriction that the data directory isn't group- or * world-accessible.) Also, since we create the lockfiles mode 600, * we'd have failed above if the lockfile belonged to another userid * --- which means that whatever process kill() is reporting about * isn't the one that made the lockfile. (NOTE: this last * consideration is the only one that keeps us from blowing away a * Unix socket file belonging to an instance of Postgres being run by * someone else, at least on machines where /tmp hasn't got a * stickybit.) * * Windows hasn't got getppid(), but doesn't need it since it's not * using real kill() either... * * Normally kill() will fail with ESRCH if the given PID doesn't * exist. */ if (other_pid != my_pid #ifndef WIN32 && other_pid != getppid() #endif ) { if (kill(other_pid, 0) == 0 || (errno != ESRCH && errno != EPERM)) { /* lockfile belongs to a live process */ ereport(FATAL, (errcode(ERRCODE_LOCK_FILE_EXISTS), errmsg("lock file \"%s\" already exists", filename), isDDLock ? (encoded_pid < 0 ? errhint("Is another postgres (PID %d) running in data directory \"%s\"?", (int) other_pid, refName) : errhint("Is another postmaster (PID %d) running in data directory \"%s\"?", (int) other_pid, refName)) : (encoded_pid < 0 ? errhint("Is another postgres (PID %d) using socket file \"%s\"?", (int) other_pid, refName) : errhint("Is another postmaster (PID %d) using socket file \"%s\"?", (int) other_pid, refName)))); } } /* * No, the creating process did not exist. However, it could be that * the postmaster crashed (or more likely was kill -9'd by a clueless * admin) but has left orphan backends behind. Check for this by * looking to see if there is an associated shmem segment that is * still in use. */ if (isDDLock) { char *ptr; unsigned long id1, id2; ptr = strchr(buffer, '\n'); if (ptr != NULL && (ptr = strchr(ptr + 1, '\n')) != NULL) { ptr++; if (sscanf(ptr, "%lu %lu", &id1, &id2) == 2) { if (PGSharedMemoryIsInUse(id1, id2)) ereport(FATAL, (errcode(ERRCODE_LOCK_FILE_EXISTS), errmsg("pre-existing shared memory block " "(key %lu, ID %lu) is still in use", id1, id2), errhint("If you're sure there are no old " "server processes still running, remove " "the shared memory block " "or just delete the file \"%s\".", filename))); } } } /* * Looks like nobody's home. Unlink the file and try again to create * it. Need a loop because of possible race condition against other * would-be creators. */ if (unlink(filename) < 0) ereport(FATAL, (errcode_for_file_access(), errmsg("could not remove old lock file \"%s\": %m", filename), errhint("The file seems accidentally left over, but " "it could not be removed. Please remove the file " "by hand and try again."))); } /* * Successfully created the file, now fill it. */ snprintf(buffer, sizeof(buffer), "%d\n%s\n", amPostmaster ? (int) my_pid : -((int) my_pid), DataDir); errno = 0; if (write(fd, buffer, strlen(buffer)) != strlen(buffer)) { int save_errno = errno; close(fd); unlink(filename); /* if write didn't set errno, assume problem is no disk space */ errno = save_errno ? save_errno : ENOSPC; ereport(FATAL, (errcode_for_file_access(), errmsg("could not write lock file \"%s\": %m", filename))); } if (close(fd)) { int save_errno = errno; unlink(filename); errno = save_errno; ereport(FATAL, (errcode_for_file_access(), errmsg("could not write lock file \"%s\": %m", filename))); } /* * Arrange for automatic removal of lockfile at proc_exit. */ on_proc_exit(UnlinkLockFile, PointerGetDatum(strdup(filename))); } /* * Create the data directory lockfile. * * When this is called, we must have already switched the working * directory to DataDir, so we can just use a relative path. This * helps ensure that we are locking the directory we should be. */ void CreateDataDirLockFile(bool amPostmaster) { CreateLockFile(DIRECTORY_LOCK_FILE, amPostmaster, true, DataDir); } /* * Create a lockfile for the specified Unix socket file. */ void CreateSocketLockFile(const char *socketfile, bool amPostmaster) { char lockfile[MAXPGPATH]; snprintf(lockfile, sizeof(lockfile), "%s.lock", socketfile); CreateLockFile(lockfile, amPostmaster, false, socketfile); /* Save name of lockfile for TouchSocketLockFile */ strcpy(socketLockFile, lockfile); } /* * TouchSocketLockFile -- mark socket lock file as recently accessed * * This routine should be called every so often to ensure that the lock file * has a recent mod or access date. That saves it * from being removed by overenthusiastic /tmp-directory-cleaner daemons. * (Another reason we should never have put the socket file in /tmp...) */ void TouchSocketLockFile(void) { /* Do nothing if we did not create a socket... */ if (socketLockFile[0] != '\0') { /* * utime() is POSIX standard, utimes() is a common alternative; if we * have neither, fall back to actually reading the file (which only * sets the access time not mod time, but that should be enough in * most cases). In all paths, we ignore errors. */ #ifdef HAVE_UTIME utime(socketLockFile, NULL); #else /* !HAVE_UTIME */ #ifdef HAVE_UTIMES utimes(socketLockFile, NULL); #else /* !HAVE_UTIMES */ int fd; char buffer[1]; fd = open(socketLockFile, O_RDONLY | PG_BINARY, 0); if (fd >= 0) { read(fd, buffer, sizeof(buffer)); close(fd); } #endif /* HAVE_UTIMES */ #endif /* HAVE_UTIME */ } } /* * Append information about a shared memory segment to the data directory * lock file. * * This may be called multiple times in the life of a postmaster, if we * delete and recreate shmem due to backend crash. Therefore, be prepared * to overwrite existing information. (As of 7.1, a postmaster only creates * one shm seg at a time; but for the purposes here, if we did have more than * one then any one of them would do anyway.) */ void RecordSharedMemoryInLockFile(unsigned long id1, unsigned long id2) { int fd; int len; char *ptr; char buffer[BLCKSZ]; fd = open(DIRECTORY_LOCK_FILE, O_RDWR | PG_BINARY, 0); if (fd < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not open file \"%s\": %m", DIRECTORY_LOCK_FILE))); return; } len = read(fd, buffer, sizeof(buffer) - 100); if (len < 0) { ereport(LOG, (errcode_for_file_access(), errmsg("could not read from file \"%s\": %m", DIRECTORY_LOCK_FILE))); close(fd); return; } buffer[len] = '\0'; /* * Skip over first two lines (PID and path). */ ptr = strchr(buffer, '\n'); if (ptr == NULL || (ptr = strchr(ptr + 1, '\n')) == NULL) { elog(LOG, "bogus data in \"%s\"", DIRECTORY_LOCK_FILE); close(fd); return; } ptr++; /* * Append key information. Format to try to keep it the same length * always (trailing junk won't hurt, but might confuse humans). */ sprintf(ptr, "%9lu %9lu\n", id1, id2); /* * And rewrite the data. Since we write in a single kernel call, this * update should appear atomic to onlookers. */ len = strlen(buffer); errno = 0; if (lseek(fd, (off_t) 0, SEEK_SET) != 0 || (int) write(fd, buffer, len) != len) { /* if write didn't set errno, assume problem is no disk space */ if (errno == 0) errno = ENOSPC; ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", DIRECTORY_LOCK_FILE))); close(fd); return; } if (close(fd)) { ereport(LOG, (errcode_for_file_access(), errmsg("could not write to file \"%s\": %m", DIRECTORY_LOCK_FILE))); } } /*------------------------------------------------------------------------- * Version checking support *------------------------------------------------------------------------- */ /* * Determine whether the PG_VERSION file in directory `path' indicates * a data version compatible with the version of this program. * * If compatible, return. Otherwise, ereport(FATAL). */ void ValidatePgVersion(const char *path) { char full_path[MAXPGPATH]; FILE *file; int ret; long file_major, file_minor; long my_major = 0, my_minor = 0; char *endptr; const char *version_string = PG_VERSION; my_major = strtol(version_string, &endptr, 10); if (*endptr == '.') my_minor = strtol(endptr + 1, NULL, 10); snprintf(full_path, sizeof(full_path), "%s/PG_VERSION", path); file = AllocateFile(full_path, "r"); if (!file) { if (errno == ENOENT) ereport(FATAL, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("\"%s\" is not a valid data directory", path), errdetail("File \"%s\" is missing.", full_path))); else ereport(FATAL, (errcode_for_file_access(), errmsg("could not open file \"%s\": %m", full_path))); } ret = fscanf(file, "%ld.%ld", &file_major, &file_minor); if (ret != 2) ereport(FATAL, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("\"%s\" is not a valid data directory", path), errdetail("File \"%s\" does not contain valid data.", full_path), errhint("You might need to initdb."))); FreeFile(file); if (my_major != file_major || my_minor != file_minor) ereport(FATAL, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), errmsg("database files are incompatible with server"), errdetail("The data directory was initialized by PostgreSQL version %ld.%ld, " "which is not compatible with this version %s.", file_major, file_minor, version_string))); } /*------------------------------------------------------------------------- * Library preload support *------------------------------------------------------------------------- */ /* * GUC variables: lists of library names to be preloaded at postmaster * start and at backend start */ char *shared_preload_libraries_string = NULL; char *local_preload_libraries_string = NULL; /* Flag telling that we are loading shared_preload_libraries */ bool process_shared_preload_libraries_in_progress = false; /* * load the shared libraries listed in 'libraries' * * 'gucname': name of GUC variable, for error reports * 'restricted': if true, force libraries to be in $libdir/plugins/ */ static void load_libraries(const char *libraries, const char *gucname, bool restricted) { char *rawstring; List *elemlist; int elevel; ListCell *l; if (libraries == NULL || libraries[0] == '\0') return; /* nothing to do */ /* Need a modifiable copy of string */ rawstring = pstrdup(libraries); /* Parse string into list of identifiers */ if (!SplitIdentifierString(rawstring, ',', &elemlist)) { /* syntax error in list */ pfree(rawstring); list_free(elemlist); ereport(LOG, (errcode(ERRCODE_SYNTAX_ERROR), errmsg("invalid list syntax in parameter \"%s\"", gucname))); return; } /* * Choose notice level: avoid repeat messages when re-loading a library * that was preloaded into the postmaster. (Only possible in EXEC_BACKEND * configurations) */ #ifdef EXEC_BACKEND if (IsUnderPostmaster && process_shared_preload_libraries_in_progress) elevel = DEBUG2; else #endif elevel = LOG; foreach(l, elemlist) { char *tok = (char *) lfirst(l); char *filename; filename = pstrdup(tok); canonicalize_path(filename); /* If restricting, insert $libdir/plugins if not mentioned already */ if (restricted && first_dir_separator(filename) == NULL) { char *expanded; expanded = palloc(strlen("$libdir/plugins/") + strlen(filename) + 1); strcpy(expanded, "$libdir/plugins/"); strcat(expanded, filename); pfree(filename); filename = expanded; } load_file(filename, restricted); ereport(elevel, (errmsg("loaded library \"%s\"", filename))); pfree(filename); } pfree(rawstring); list_free(elemlist); } /* * process any libraries that should be preloaded at postmaster start */ void process_shared_preload_libraries(void) { process_shared_preload_libraries_in_progress = true; load_libraries(shared_preload_libraries_string, "shared_preload_libraries", false); process_shared_preload_libraries_in_progress = false; } /* * process any libraries that should be preloaded at backend start */ void process_local_preload_libraries(void) { load_libraries(local_preload_libraries_string, "local_preload_libraries", true); } void pg_bindtextdomain(const char *domain) { #ifdef ENABLE_NLS if (my_exec_path[0] != '\0') { char locale_path[MAXPGPATH]; get_locale_path(my_exec_path, locale_path); bindtextdomain(domain, locale_path); pg_bind_textdomain_codeset(domain); } #endif }