LCOV - code coverage report
Current view: top level - src/backend/commands - dbcommands.c (source / functions) Hit Total Coverage
Test: PostgreSQL 17devel Lines: 888 1089 81.5 %
Date: 2024-04-13 08:11:04 Functions: 26 30 86.7 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*-------------------------------------------------------------------------
       2             :  *
       3             :  * dbcommands.c
       4             :  *      Database management commands (create/drop database).
       5             :  *
       6             :  * Note: database creation/destruction commands use exclusive locks on
       7             :  * the database objects (as expressed by LockSharedObject()) to avoid
       8             :  * stepping on each others' toes.  Formerly we used table-level locks
       9             :  * on pg_database, but that's too coarse-grained.
      10             :  *
      11             :  * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
      12             :  * Portions Copyright (c) 1994, Regents of the University of California
      13             :  *
      14             :  *
      15             :  * IDENTIFICATION
      16             :  *    src/backend/commands/dbcommands.c
      17             :  *
      18             :  *-------------------------------------------------------------------------
      19             :  */
      20             : #include "postgres.h"
      21             : 
      22             : #include <fcntl.h>
      23             : #include <unistd.h>
      24             : #include <sys/stat.h>
      25             : 
      26             : #include "access/genam.h"
      27             : #include "access/heapam.h"
      28             : #include "access/htup_details.h"
      29             : #include "access/multixact.h"
      30             : #include "access/tableam.h"
      31             : #include "access/xact.h"
      32             : #include "access/xloginsert.h"
      33             : #include "access/xlogrecovery.h"
      34             : #include "access/xlogutils.h"
      35             : #include "catalog/catalog.h"
      36             : #include "catalog/dependency.h"
      37             : #include "catalog/indexing.h"
      38             : #include "catalog/objectaccess.h"
      39             : #include "catalog/pg_authid.h"
      40             : #include "catalog/pg_collation.h"
      41             : #include "catalog/pg_database.h"
      42             : #include "catalog/pg_db_role_setting.h"
      43             : #include "catalog/pg_subscription.h"
      44             : #include "catalog/pg_tablespace.h"
      45             : #include "commands/comment.h"
      46             : #include "commands/dbcommands.h"
      47             : #include "commands/dbcommands_xlog.h"
      48             : #include "commands/defrem.h"
      49             : #include "commands/seclabel.h"
      50             : #include "commands/tablespace.h"
      51             : #include "common/file_perm.h"
      52             : #include "mb/pg_wchar.h"
      53             : #include "miscadmin.h"
      54             : #include "pgstat.h"
      55             : #include "postmaster/bgwriter.h"
      56             : #include "replication/slot.h"
      57             : #include "storage/copydir.h"
      58             : #include "storage/fd.h"
      59             : #include "storage/ipc.h"
      60             : #include "storage/lmgr.h"
      61             : #include "storage/md.h"
      62             : #include "storage/procarray.h"
      63             : #include "storage/smgr.h"
      64             : #include "utils/acl.h"
      65             : #include "utils/builtins.h"
      66             : #include "utils/fmgroids.h"
      67             : #include "utils/pg_locale.h"
      68             : #include "utils/relmapper.h"
      69             : #include "utils/snapmgr.h"
      70             : #include "utils/syscache.h"
      71             : 
      72             : /*
      73             :  * Create database strategy.
      74             :  *
      75             :  * CREATEDB_WAL_LOG will copy the database at the block level and WAL log each
      76             :  * copied block.
      77             :  *
      78             :  * CREATEDB_FILE_COPY will simply perform a file system level copy of the
      79             :  * database and log a single record for each tablespace copied. To make this
      80             :  * safe, it also triggers checkpoints before and after the operation.
      81             :  */
      82             : typedef enum CreateDBStrategy
      83             : {
      84             :     CREATEDB_WAL_LOG,
      85             :     CREATEDB_FILE_COPY,
      86             : } CreateDBStrategy;
      87             : 
      88             : typedef struct
      89             : {
      90             :     Oid         src_dboid;      /* source (template) DB */
      91             :     Oid         dest_dboid;     /* DB we are trying to create */
      92             :     CreateDBStrategy strategy;  /* create db strategy */
      93             : } createdb_failure_params;
      94             : 
      95             : typedef struct
      96             : {
      97             :     Oid         dest_dboid;     /* DB we are trying to move */
      98             :     Oid         dest_tsoid;     /* tablespace we are trying to move to */
      99             : } movedb_failure_params;
     100             : 
     101             : /*
     102             :  * Information about a relation to be copied when creating a database.
     103             :  */
     104             : typedef struct CreateDBRelInfo
     105             : {
     106             :     RelFileLocator rlocator;    /* physical relation identifier */
     107             :     Oid         reloid;         /* relation oid */
     108             :     bool        permanent;      /* relation is permanent or unlogged */
     109             : } CreateDBRelInfo;
     110             : 
     111             : 
     112             : /* non-export function prototypes */
     113             : static void createdb_failure_callback(int code, Datum arg);
     114             : static void movedb(const char *dbname, const char *tblspcname);
     115             : static void movedb_failure_callback(int code, Datum arg);
     116             : static bool get_db_info(const char *name, LOCKMODE lockmode,
     117             :                         Oid *dbIdP, Oid *ownerIdP,
     118             :                         int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP, bool *dbHasLoginEvtP,
     119             :                         TransactionId *dbFrozenXidP, MultiXactId *dbMinMultiP,
     120             :                         Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbLocale,
     121             :                         char **dbIcurules,
     122             :                         char *dbLocProvider,
     123             :                         char **dbCollversion);
     124             : static void remove_dbtablespaces(Oid db_id);
     125             : static bool check_db_file_conflict(Oid db_id);
     126             : static int  errdetail_busy_db(int notherbackends, int npreparedxacts);
     127             : static void CreateDatabaseUsingWalLog(Oid src_dboid, Oid dst_dboid, Oid src_tsid,
     128             :                                       Oid dst_tsid);
     129             : static List *ScanSourceDatabasePgClass(Oid tbid, Oid dbid, char *srcpath);
     130             : static List *ScanSourceDatabasePgClassPage(Page page, Buffer buf, Oid tbid,
     131             :                                            Oid dbid, char *srcpath,
     132             :                                            List *rlocatorlist, Snapshot snapshot);
     133             : static CreateDBRelInfo *ScanSourceDatabasePgClassTuple(HeapTupleData *tuple,
     134             :                                                        Oid tbid, Oid dbid,
     135             :                                                        char *srcpath);
     136             : static void CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid,
     137             :                                     bool isRedo);
     138             : static void CreateDatabaseUsingFileCopy(Oid src_dboid, Oid dst_dboid,
     139             :                                         Oid src_tsid, Oid dst_tsid);
     140             : static void recovery_create_dbdir(char *path, bool only_tblspc);
     141             : 
     142             : /*
     143             :  * Create a new database using the WAL_LOG strategy.
     144             :  *
     145             :  * Each copied block is separately written to the write-ahead log.
     146             :  */
     147             : static void
     148         432 : CreateDatabaseUsingWalLog(Oid src_dboid, Oid dst_dboid,
     149             :                           Oid src_tsid, Oid dst_tsid)
     150             : {
     151             :     char       *srcpath;
     152             :     char       *dstpath;
     153         432 :     List       *rlocatorlist = NULL;
     154             :     ListCell   *cell;
     155             :     LockRelId   srcrelid;
     156             :     LockRelId   dstrelid;
     157             :     RelFileLocator srcrlocator;
     158             :     RelFileLocator dstrlocator;
     159             :     CreateDBRelInfo *relinfo;
     160             : 
     161             :     /* Get source and destination database paths. */
     162         432 :     srcpath = GetDatabasePath(src_dboid, src_tsid);
     163         432 :     dstpath = GetDatabasePath(dst_dboid, dst_tsid);
     164             : 
     165             :     /* Create database directory and write PG_VERSION file. */
     166         432 :     CreateDirAndVersionFile(dstpath, dst_dboid, dst_tsid, false);
     167             : 
     168             :     /* Copy relmap file from source database to the destination database. */
     169         432 :     RelationMapCopy(dst_dboid, dst_tsid, srcpath, dstpath);
     170             : 
     171             :     /* Get list of relfilelocators to copy from the source database. */
     172         432 :     rlocatorlist = ScanSourceDatabasePgClass(src_tsid, src_dboid, srcpath);
     173             :     Assert(rlocatorlist != NIL);
     174             : 
     175             :     /*
     176             :      * Database IDs will be the same for all relations so set them before
     177             :      * entering the loop.
     178             :      */
     179         432 :     srcrelid.dbId = src_dboid;
     180         432 :     dstrelid.dbId = dst_dboid;
     181             : 
     182             :     /* Loop over our list of relfilelocators and copy each one. */
     183       96366 :     foreach(cell, rlocatorlist)
     184             :     {
     185       95934 :         relinfo = lfirst(cell);
     186       95934 :         srcrlocator = relinfo->rlocator;
     187             : 
     188             :         /*
     189             :          * If the relation is from the source db's default tablespace then we
     190             :          * need to create it in the destination db's default tablespace.
     191             :          * Otherwise, we need to create in the same tablespace as it is in the
     192             :          * source database.
     193             :          */
     194       95934 :         if (srcrlocator.spcOid == src_tsid)
     195       95934 :             dstrlocator.spcOid = dst_tsid;
     196             :         else
     197           0 :             dstrlocator.spcOid = srcrlocator.spcOid;
     198             : 
     199       95934 :         dstrlocator.dbOid = dst_dboid;
     200       95934 :         dstrlocator.relNumber = srcrlocator.relNumber;
     201             : 
     202             :         /*
     203             :          * Acquire locks on source and target relations before copying.
     204             :          *
     205             :          * We typically do not read relation data into shared_buffers without
     206             :          * holding a relation lock. It's unclear what could go wrong if we
     207             :          * skipped it in this case, because nobody can be modifying either the
     208             :          * source or destination database at this point, and we have locks on
     209             :          * both databases, too, but let's take the conservative route.
     210             :          */
     211       95934 :         dstrelid.relId = srcrelid.relId = relinfo->reloid;
     212       95934 :         LockRelationId(&srcrelid, AccessShareLock);
     213       95934 :         LockRelationId(&dstrelid, AccessShareLock);
     214             : 
     215             :         /* Copy relation storage from source to the destination. */
     216       95934 :         CreateAndCopyRelationData(srcrlocator, dstrlocator, relinfo->permanent);
     217             : 
     218             :         /* Release the relation locks. */
     219       95934 :         UnlockRelationId(&srcrelid, AccessShareLock);
     220       95934 :         UnlockRelationId(&dstrelid, AccessShareLock);
     221             :     }
     222             : 
     223         432 :     pfree(srcpath);
     224         432 :     pfree(dstpath);
     225         432 :     list_free_deep(rlocatorlist);
     226         432 : }
     227             : 
     228             : /*
     229             :  * Scan the pg_class table in the source database to identify the relations
     230             :  * that need to be copied to the destination database.
     231             :  *
     232             :  * This is an exception to the usual rule that cross-database access is
     233             :  * not possible. We can make it work here because we know that there are no
     234             :  * connections to the source database and (since there can't be prepared
     235             :  * transactions touching that database) no in-doubt tuples either. This
     236             :  * means that we don't need to worry about pruning removing anything from
     237             :  * under us, and we don't need to be too picky about our snapshot either.
     238             :  * As long as it sees all previously-committed XIDs as committed and all
     239             :  * aborted XIDs as aborted, we should be fine: nothing else is possible
     240             :  * here.
     241             :  *
     242             :  * We can't rely on the relcache for anything here, because that only knows
     243             :  * about the database to which we are connected, and can't handle access to
     244             :  * other databases. That also means we can't rely on the heap scan
     245             :  * infrastructure, which would be a bad idea anyway since it might try
     246             :  * to do things like HOT pruning which we definitely can't do safely in
     247             :  * a database to which we're not even connected.
     248             :  */
     249             : static List *
     250         432 : ScanSourceDatabasePgClass(Oid tbid, Oid dbid, char *srcpath)
     251             : {
     252             :     RelFileLocator rlocator;
     253             :     BlockNumber nblocks;
     254             :     BlockNumber blkno;
     255             :     Buffer      buf;
     256             :     RelFileNumber relfilenumber;
     257             :     Page        page;
     258         432 :     List       *rlocatorlist = NIL;
     259             :     LockRelId   relid;
     260             :     Snapshot    snapshot;
     261             :     SMgrRelation smgr;
     262             :     BufferAccessStrategy bstrategy;
     263             : 
     264             :     /* Get pg_class relfilenumber. */
     265         432 :     relfilenumber = RelationMapOidToFilenumberForDatabase(srcpath,
     266             :                                                           RelationRelationId);
     267             : 
     268             :     /* Don't read data into shared_buffers without holding a relation lock. */
     269         432 :     relid.dbId = dbid;
     270         432 :     relid.relId = RelationRelationId;
     271         432 :     LockRelationId(&relid, AccessShareLock);
     272             : 
     273             :     /* Prepare a RelFileLocator for the pg_class relation. */
     274         432 :     rlocator.spcOid = tbid;
     275         432 :     rlocator.dbOid = dbid;
     276         432 :     rlocator.relNumber = relfilenumber;
     277             : 
     278         432 :     smgr = smgropen(rlocator, INVALID_PROC_NUMBER);
     279         432 :     nblocks = smgrnblocks(smgr, MAIN_FORKNUM);
     280         432 :     smgrclose(smgr);
     281             : 
     282             :     /* Use a buffer access strategy since this is a bulk read operation. */
     283         432 :     bstrategy = GetAccessStrategy(BAS_BULKREAD);
     284             : 
     285             :     /*
     286             :      * As explained in the function header comments, we need a snapshot that
     287             :      * will see all committed transactions as committed, and our transaction
     288             :      * snapshot - or the active snapshot - might not be new enough for that,
     289             :      * but the return value of GetLatestSnapshot() should work fine.
     290             :      */
     291         432 :     snapshot = GetLatestSnapshot();
     292             : 
     293             :     /* Process the relation block by block. */
     294        6520 :     for (blkno = 0; blkno < nblocks; blkno++)
     295             :     {
     296        6088 :         CHECK_FOR_INTERRUPTS();
     297             : 
     298        6088 :         buf = ReadBufferWithoutRelcache(rlocator, MAIN_FORKNUM, blkno,
     299             :                                         RBM_NORMAL, bstrategy, true);
     300             : 
     301        6088 :         LockBuffer(buf, BUFFER_LOCK_SHARE);
     302        6088 :         page = BufferGetPage(buf);
     303        6088 :         if (PageIsNew(page) || PageIsEmpty(page))
     304             :         {
     305           0 :             UnlockReleaseBuffer(buf);
     306           0 :             continue;
     307             :         }
     308             : 
     309             :         /* Append relevant pg_class tuples for current page to rlocatorlist. */
     310        6088 :         rlocatorlist = ScanSourceDatabasePgClassPage(page, buf, tbid, dbid,
     311             :                                                      srcpath, rlocatorlist,
     312             :                                                      snapshot);
     313             : 
     314        6088 :         UnlockReleaseBuffer(buf);
     315             :     }
     316             : 
     317             :     /* Release relation lock. */
     318         432 :     UnlockRelationId(&relid, AccessShareLock);
     319             : 
     320         432 :     return rlocatorlist;
     321             : }
     322             : 
     323             : /*
     324             :  * Scan one page of the source database's pg_class relation and add relevant
     325             :  * entries to rlocatorlist. The return value is the updated list.
     326             :  */
     327             : static List *
     328        6088 : ScanSourceDatabasePgClassPage(Page page, Buffer buf, Oid tbid, Oid dbid,
     329             :                               char *srcpath, List *rlocatorlist,
     330             :                               Snapshot snapshot)
     331             : {
     332        6088 :     BlockNumber blkno = BufferGetBlockNumber(buf);
     333             :     OffsetNumber offnum;
     334             :     OffsetNumber maxoff;
     335             :     HeapTupleData tuple;
     336             : 
     337        6088 :     maxoff = PageGetMaxOffsetNumber(page);
     338             : 
     339             :     /* Loop over offsets. */
     340      311882 :     for (offnum = FirstOffsetNumber;
     341             :          offnum <= maxoff;
     342      305794 :          offnum = OffsetNumberNext(offnum))
     343             :     {
     344             :         ItemId      itemid;
     345             : 
     346      305794 :         itemid = PageGetItemId(page, offnum);
     347             : 
     348             :         /* Nothing to do if slot is empty or already dead. */
     349      305794 :         if (!ItemIdIsUsed(itemid) || ItemIdIsDead(itemid) ||
     350      218638 :             ItemIdIsRedirected(itemid))
     351      124296 :             continue;
     352             : 
     353             :         Assert(ItemIdIsNormal(itemid));
     354      181498 :         ItemPointerSet(&(tuple.t_self), blkno, offnum);
     355             : 
     356             :         /* Initialize a HeapTupleData structure. */
     357      181498 :         tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
     358      181498 :         tuple.t_len = ItemIdGetLength(itemid);
     359      181498 :         tuple.t_tableOid = RelationRelationId;
     360             : 
     361             :         /* Skip tuples that are not visible to this snapshot. */
     362      181498 :         if (HeapTupleSatisfiesVisibility(&tuple, snapshot, buf))
     363             :         {
     364             :             CreateDBRelInfo *relinfo;
     365             : 
     366             :             /*
     367             :              * ScanSourceDatabasePgClassTuple is in charge of constructing a
     368             :              * CreateDBRelInfo object for this tuple, but can also decide that
     369             :              * this tuple isn't something we need to copy. If we do need to
     370             :              * copy the relation, add it to the list.
     371             :              */
     372      179310 :             relinfo = ScanSourceDatabasePgClassTuple(&tuple, tbid, dbid,
     373             :                                                      srcpath);
     374      179310 :             if (relinfo != NULL)
     375       95934 :                 rlocatorlist = lappend(rlocatorlist, relinfo);
     376             :         }
     377             :     }
     378             : 
     379        6088 :     return rlocatorlist;
     380             : }
     381             : 
     382             : /*
     383             :  * Decide whether a certain pg_class tuple represents something that
     384             :  * needs to be copied from the source database to the destination database,
     385             :  * and if so, construct a CreateDBRelInfo for it.
     386             :  *
     387             :  * Visibility checks are handled by the caller, so our job here is just
     388             :  * to assess the data stored in the tuple.
     389             :  */
     390             : CreateDBRelInfo *
     391      179310 : ScanSourceDatabasePgClassTuple(HeapTupleData *tuple, Oid tbid, Oid dbid,
     392             :                                char *srcpath)
     393             : {
     394             :     CreateDBRelInfo *relinfo;
     395             :     Form_pg_class classForm;
     396      179310 :     RelFileNumber relfilenumber = InvalidRelFileNumber;
     397             : 
     398      179310 :     classForm = (Form_pg_class) GETSTRUCT(tuple);
     399             : 
     400             :     /*
     401             :      * Return NULL if this object does not need to be copied.
     402             :      *
     403             :      * Shared objects don't need to be copied, because they are shared.
     404             :      * Objects without storage can't be copied, because there's nothing to
     405             :      * copy. Temporary relations don't need to be copied either, because they
     406             :      * are inaccessible outside of the session that created them, which must
     407             :      * be gone already, and couldn't connect to a different database if it
     408             :      * still existed. autovacuum will eventually remove the pg_class entries
     409             :      * as well.
     410             :      */
     411      179310 :     if (classForm->reltablespace == GLOBALTABLESPACE_OID ||
     412      157710 :         !RELKIND_HAS_STORAGE(classForm->relkind) ||
     413       95934 :         classForm->relpersistence == RELPERSISTENCE_TEMP)
     414       83376 :         return NULL;
     415             : 
     416             :     /*
     417             :      * If relfilenumber is valid then directly use it.  Otherwise, consult the
     418             :      * relmap.
     419             :      */
     420       95934 :     if (RelFileNumberIsValid(classForm->relfilenode))
     421       88590 :         relfilenumber = classForm->relfilenode;
     422             :     else
     423        7344 :         relfilenumber = RelationMapOidToFilenumberForDatabase(srcpath,
     424             :                                                               classForm->oid);
     425             : 
     426             :     /* We must have a valid relfilenumber. */
     427       95934 :     if (!RelFileNumberIsValid(relfilenumber))
     428           0 :         elog(ERROR, "relation with OID %u does not have a valid relfilenumber",
     429             :              classForm->oid);
     430             : 
     431             :     /* Prepare a rel info element and add it to the list. */
     432       95934 :     relinfo = (CreateDBRelInfo *) palloc(sizeof(CreateDBRelInfo));
     433       95934 :     if (OidIsValid(classForm->reltablespace))
     434           0 :         relinfo->rlocator.spcOid = classForm->reltablespace;
     435             :     else
     436       95934 :         relinfo->rlocator.spcOid = tbid;
     437             : 
     438       95934 :     relinfo->rlocator.dbOid = dbid;
     439       95934 :     relinfo->rlocator.relNumber = relfilenumber;
     440       95934 :     relinfo->reloid = classForm->oid;
     441             : 
     442             :     /* Temporary relations were rejected above. */
     443             :     Assert(classForm->relpersistence != RELPERSISTENCE_TEMP);
     444       95934 :     relinfo->permanent =
     445       95934 :         (classForm->relpersistence == RELPERSISTENCE_PERMANENT) ? true : false;
     446             : 
     447       95934 :     return relinfo;
     448             : }
     449             : 
     450             : /*
     451             :  * Create database directory and write out the PG_VERSION file in the database
     452             :  * path.  If isRedo is true, it's okay for the database directory to exist
     453             :  * already.
     454             :  */
     455             : static void
     456         472 : CreateDirAndVersionFile(char *dbpath, Oid dbid, Oid tsid, bool isRedo)
     457             : {
     458             :     int         fd;
     459             :     int         nbytes;
     460             :     char        versionfile[MAXPGPATH];
     461             :     char        buf[16];
     462             : 
     463             :     /*
     464             :      * Note that we don't have to copy version data from the source database;
     465             :      * there's only one legal value.
     466             :      */
     467         472 :     sprintf(buf, "%s\n", PG_MAJORVERSION);
     468         472 :     nbytes = strlen(PG_MAJORVERSION) + 1;
     469             : 
     470             :     /* Create database directory. */
     471         472 :     if (MakePGDirectory(dbpath) < 0)
     472             :     {
     473             :         /* Failure other than already exists or not in WAL replay? */
     474          16 :         if (errno != EEXIST || !isRedo)
     475           0 :             ereport(ERROR,
     476             :                     (errcode_for_file_access(),
     477             :                      errmsg("could not create directory \"%s\": %m", dbpath)));
     478             :     }
     479             : 
     480             :     /*
     481             :      * Create PG_VERSION file in the database path.  If the file already
     482             :      * exists and we are in WAL replay then try again to open it in write
     483             :      * mode.
     484             :      */
     485         472 :     snprintf(versionfile, sizeof(versionfile), "%s/%s", dbpath, "PG_VERSION");
     486             : 
     487         472 :     fd = OpenTransientFile(versionfile, O_WRONLY | O_CREAT | O_EXCL | PG_BINARY);
     488         472 :     if (fd < 0 && errno == EEXIST && isRedo)
     489          16 :         fd = OpenTransientFile(versionfile, O_WRONLY | O_TRUNC | PG_BINARY);
     490             : 
     491         472 :     if (fd < 0)
     492           0 :         ereport(ERROR,
     493             :                 (errcode_for_file_access(),
     494             :                  errmsg("could not create file \"%s\": %m", versionfile)));
     495             : 
     496             :     /* Write PG_MAJORVERSION in the PG_VERSION file. */
     497         472 :     pgstat_report_wait_start(WAIT_EVENT_VERSION_FILE_WRITE);
     498         472 :     errno = 0;
     499         472 :     if ((int) write(fd, buf, nbytes) != nbytes)
     500             :     {
     501             :         /* If write didn't set errno, assume problem is no disk space. */
     502           0 :         if (errno == 0)
     503           0 :             errno = ENOSPC;
     504           0 :         ereport(ERROR,
     505             :                 (errcode_for_file_access(),
     506             :                  errmsg("could not write to file \"%s\": %m", versionfile)));
     507             :     }
     508         472 :     pgstat_report_wait_end();
     509             : 
     510         472 :     pgstat_report_wait_start(WAIT_EVENT_VERSION_FILE_SYNC);
     511         472 :     if (pg_fsync(fd) != 0)
     512           0 :         ereport(data_sync_elevel(ERROR),
     513             :                 (errcode_for_file_access(),
     514             :                  errmsg("could not fsync file \"%s\": %m", versionfile)));
     515         472 :     fsync_fname(dbpath, true);
     516         472 :     pgstat_report_wait_end();
     517             : 
     518             :     /* Close the version file. */
     519         472 :     CloseTransientFile(fd);
     520             : 
     521             :     /* If we are not in WAL replay then write the WAL. */
     522         472 :     if (!isRedo)
     523             :     {
     524             :         xl_dbase_create_wal_log_rec xlrec;
     525             : 
     526         432 :         START_CRIT_SECTION();
     527             : 
     528         432 :         xlrec.db_id = dbid;
     529         432 :         xlrec.tablespace_id = tsid;
     530             : 
     531         432 :         XLogBeginInsert();
     532         432 :         XLogRegisterData((char *) (&xlrec),
     533             :                          sizeof(xl_dbase_create_wal_log_rec));
     534             : 
     535         432 :         (void) XLogInsert(RM_DBASE_ID, XLOG_DBASE_CREATE_WAL_LOG);
     536             : 
     537         432 :         END_CRIT_SECTION();
     538             :     }
     539         472 : }
     540             : 
     541             : /*
     542             :  * Create a new database using the FILE_COPY strategy.
     543             :  *
     544             :  * Copy each tablespace at the filesystem level, and log a single WAL record
     545             :  * for each tablespace copied.  This requires a checkpoint before and after the
     546             :  * copy, which may be expensive, but it does greatly reduce WAL generation
     547             :  * if the copied database is large.
     548             :  */
     549             : static void
     550         170 : CreateDatabaseUsingFileCopy(Oid src_dboid, Oid dst_dboid, Oid src_tsid,
     551             :                             Oid dst_tsid)
     552             : {
     553             :     TableScanDesc scan;
     554             :     Relation    rel;
     555             :     HeapTuple   tuple;
     556             : 
     557             :     /*
     558             :      * Force a checkpoint before starting the copy. This will force all dirty
     559             :      * buffers, including those of unlogged tables, out to disk, to ensure
     560             :      * source database is up-to-date on disk for the copy.
     561             :      * FlushDatabaseBuffers() would suffice for that, but we also want to
     562             :      * process any pending unlink requests. Otherwise, if a checkpoint
     563             :      * happened while we're copying files, a file might be deleted just when
     564             :      * we're about to copy it, causing the lstat() call in copydir() to fail
     565             :      * with ENOENT.
     566             :      */
     567         170 :     RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE |
     568             :                       CHECKPOINT_WAIT | CHECKPOINT_FLUSH_ALL);
     569             : 
     570             :     /*
     571             :      * Iterate through all tablespaces of the template database, and copy each
     572             :      * one to the new database.
     573             :      */
     574         170 :     rel = table_open(TableSpaceRelationId, AccessShareLock);
     575         170 :     scan = table_beginscan_catalog(rel, 0, NULL);
     576         546 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
     577             :     {
     578         376 :         Form_pg_tablespace spaceform = (Form_pg_tablespace) GETSTRUCT(tuple);
     579         376 :         Oid         srctablespace = spaceform->oid;
     580             :         Oid         dsttablespace;
     581             :         char       *srcpath;
     582             :         char       *dstpath;
     583             :         struct stat st;
     584             : 
     585             :         /* No need to copy global tablespace */
     586         376 :         if (srctablespace == GLOBALTABLESPACE_OID)
     587         206 :             continue;
     588             : 
     589         206 :         srcpath = GetDatabasePath(src_dboid, srctablespace);
     590             : 
     591         376 :         if (stat(srcpath, &st) < 0 || !S_ISDIR(st.st_mode) ||
     592         170 :             directory_is_empty(srcpath))
     593             :         {
     594             :             /* Assume we can ignore it */
     595          36 :             pfree(srcpath);
     596          36 :             continue;
     597             :         }
     598             : 
     599         170 :         if (srctablespace == src_tsid)
     600         170 :             dsttablespace = dst_tsid;
     601             :         else
     602           0 :             dsttablespace = srctablespace;
     603             : 
     604         170 :         dstpath = GetDatabasePath(dst_dboid, dsttablespace);
     605             : 
     606             :         /*
     607             :          * Copy this subdirectory to the new location
     608             :          *
     609             :          * We don't need to copy subdirectories
     610             :          */
     611         170 :         copydir(srcpath, dstpath, false);
     612             : 
     613             :         /* Record the filesystem change in XLOG */
     614             :         {
     615             :             xl_dbase_create_file_copy_rec xlrec;
     616             : 
     617         170 :             xlrec.db_id = dst_dboid;
     618         170 :             xlrec.tablespace_id = dsttablespace;
     619         170 :             xlrec.src_db_id = src_dboid;
     620         170 :             xlrec.src_tablespace_id = srctablespace;
     621             : 
     622         170 :             XLogBeginInsert();
     623         170 :             XLogRegisterData((char *) &xlrec,
     624             :                              sizeof(xl_dbase_create_file_copy_rec));
     625             : 
     626         170 :             (void) XLogInsert(RM_DBASE_ID,
     627             :                               XLOG_DBASE_CREATE_FILE_COPY | XLR_SPECIAL_REL_UPDATE);
     628             :         }
     629         170 :         pfree(srcpath);
     630         170 :         pfree(dstpath);
     631             :     }
     632         170 :     table_endscan(scan);
     633         170 :     table_close(rel, AccessShareLock);
     634             : 
     635             :     /*
     636             :      * We force a checkpoint before committing.  This effectively means that
     637             :      * committed XLOG_DBASE_CREATE_FILE_COPY operations will never need to be
     638             :      * replayed (at least not in ordinary crash recovery; we still have to
     639             :      * make the XLOG entry for the benefit of PITR operations). This avoids
     640             :      * two nasty scenarios:
     641             :      *
     642             :      * #1: When PITR is off, we don't XLOG the contents of newly created
     643             :      * indexes; therefore the drop-and-recreate-whole-directory behavior of
     644             :      * DBASE_CREATE replay would lose such indexes.
     645             :      *
     646             :      * #2: Since we have to recopy the source database during DBASE_CREATE
     647             :      * replay, we run the risk of copying changes in it that were committed
     648             :      * after the original CREATE DATABASE command but before the system crash
     649             :      * that led to the replay.  This is at least unexpected and at worst could
     650             :      * lead to inconsistencies, eg duplicate table names.
     651             :      *
     652             :      * (Both of these were real bugs in releases 8.0 through 8.0.3.)
     653             :      *
     654             :      * In PITR replay, the first of these isn't an issue, and the second is
     655             :      * only a risk if the CREATE DATABASE and subsequent template database
     656             :      * change both occur while a base backup is being taken. There doesn't
     657             :      * seem to be much we can do about that except document it as a
     658             :      * limitation.
     659             :      *
     660             :      * See CreateDatabaseUsingWalLog() for a less cheesy CREATE DATABASE
     661             :      * strategy that avoids these problems.
     662             :      */
     663         170 :     RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
     664         170 : }
     665             : 
     666             : /*
     667             :  * CREATE DATABASE
     668             :  */
     669             : Oid
     670         636 : createdb(ParseState *pstate, const CreatedbStmt *stmt)
     671             : {
     672             :     Oid         src_dboid;
     673             :     Oid         src_owner;
     674         636 :     int         src_encoding = -1;
     675         636 :     char       *src_collate = NULL;
     676         636 :     char       *src_ctype = NULL;
     677         636 :     char       *src_locale = NULL;
     678         636 :     char       *src_icurules = NULL;
     679         636 :     char        src_locprovider = '\0';
     680         636 :     char       *src_collversion = NULL;
     681             :     bool        src_istemplate;
     682         636 :     bool        src_hasloginevt = false;
     683             :     bool        src_allowconn;
     684         636 :     TransactionId src_frozenxid = InvalidTransactionId;
     685         636 :     MultiXactId src_minmxid = InvalidMultiXactId;
     686             :     Oid         src_deftablespace;
     687             :     volatile Oid dst_deftablespace;
     688             :     Relation    pg_database_rel;
     689             :     HeapTuple   tuple;
     690         636 :     Datum       new_record[Natts_pg_database] = {0};
     691         636 :     bool        new_record_nulls[Natts_pg_database] = {0};
     692         636 :     Oid         dboid = InvalidOid;
     693             :     Oid         datdba;
     694             :     ListCell   *option;
     695         636 :     DefElem    *dtablespacename = NULL;
     696         636 :     DefElem    *downer = NULL;
     697         636 :     DefElem    *dtemplate = NULL;
     698         636 :     DefElem    *dencoding = NULL;
     699         636 :     DefElem    *dlocale = NULL;
     700         636 :     DefElem    *dbuiltinlocale = NULL;
     701         636 :     DefElem    *dcollate = NULL;
     702         636 :     DefElem    *dctype = NULL;
     703         636 :     DefElem    *diculocale = NULL;
     704         636 :     DefElem    *dicurules = NULL;
     705         636 :     DefElem    *dlocprovider = NULL;
     706         636 :     DefElem    *distemplate = NULL;
     707         636 :     DefElem    *dallowconnections = NULL;
     708         636 :     DefElem    *dconnlimit = NULL;
     709         636 :     DefElem    *dcollversion = NULL;
     710         636 :     DefElem    *dstrategy = NULL;
     711         636 :     char       *dbname = stmt->dbname;
     712         636 :     char       *dbowner = NULL;
     713         636 :     const char *dbtemplate = NULL;
     714         636 :     char       *dbcollate = NULL;
     715         636 :     char       *dbctype = NULL;
     716         636 :     const char *dblocale = NULL;
     717         636 :     char       *dbicurules = NULL;
     718         636 :     char        dblocprovider = '\0';
     719             :     char       *canonname;
     720         636 :     int         encoding = -1;
     721         636 :     bool        dbistemplate = false;
     722         636 :     bool        dballowconnections = true;
     723         636 :     int         dbconnlimit = DATCONNLIMIT_UNLIMITED;
     724         636 :     char       *dbcollversion = NULL;
     725             :     int         notherbackends;
     726             :     int         npreparedxacts;
     727         636 :     CreateDBStrategy dbstrategy = CREATEDB_WAL_LOG;
     728             :     createdb_failure_params fparms;
     729             : 
     730             :     /* Extract options from the statement node tree */
     731        1732 :     foreach(option, stmt->options)
     732             :     {
     733        1096 :         DefElem    *defel = (DefElem *) lfirst(option);
     734             : 
     735        1096 :         if (strcmp(defel->defname, "tablespace") == 0)
     736             :         {
     737          16 :             if (dtablespacename)
     738           0 :                 errorConflictingDefElem(defel, pstate);
     739          16 :             dtablespacename = defel;
     740             :         }
     741        1080 :         else if (strcmp(defel->defname, "owner") == 0)
     742             :         {
     743           2 :             if (downer)
     744           0 :                 errorConflictingDefElem(defel, pstate);
     745           2 :             downer = defel;
     746             :         }
     747        1078 :         else if (strcmp(defel->defname, "template") == 0)
     748             :         {
     749         276 :             if (dtemplate)
     750           0 :                 errorConflictingDefElem(defel, pstate);
     751         276 :             dtemplate = defel;
     752             :         }
     753         802 :         else if (strcmp(defel->defname, "encoding") == 0)
     754             :         {
     755          60 :             if (dencoding)
     756           0 :                 errorConflictingDefElem(defel, pstate);
     757          60 :             dencoding = defel;
     758             :         }
     759         742 :         else if (strcmp(defel->defname, "locale") == 0)
     760             :         {
     761          70 :             if (dlocale)
     762           0 :                 errorConflictingDefElem(defel, pstate);
     763          70 :             dlocale = defel;
     764             :         }
     765         672 :         else if (strcmp(defel->defname, "builtin_locale") == 0)
     766             :         {
     767          16 :             if (dbuiltinlocale)
     768           0 :                 errorConflictingDefElem(defel, pstate);
     769          16 :             dbuiltinlocale = defel;
     770             :         }
     771         656 :         else if (strcmp(defel->defname, "lc_collate") == 0)
     772             :         {
     773          12 :             if (dcollate)
     774           0 :                 errorConflictingDefElem(defel, pstate);
     775          12 :             dcollate = defel;
     776             :         }
     777         644 :         else if (strcmp(defel->defname, "lc_ctype") == 0)
     778             :         {
     779          12 :             if (dctype)
     780           0 :                 errorConflictingDefElem(defel, pstate);
     781          12 :             dctype = defel;
     782             :         }
     783         632 :         else if (strcmp(defel->defname, "icu_locale") == 0)
     784             :         {
     785          10 :             if (diculocale)
     786           0 :                 errorConflictingDefElem(defel, pstate);
     787          10 :             diculocale = defel;
     788             :         }
     789         622 :         else if (strcmp(defel->defname, "icu_rules") == 0)
     790             :         {
     791           2 :             if (dicurules)
     792           0 :                 errorConflictingDefElem(defel, pstate);
     793           2 :             dicurules = defel;
     794             :         }
     795         620 :         else if (strcmp(defel->defname, "locale_provider") == 0)
     796             :         {
     797          76 :             if (dlocprovider)
     798           0 :                 errorConflictingDefElem(defel, pstate);
     799          76 :             dlocprovider = defel;
     800             :         }
     801         544 :         else if (strcmp(defel->defname, "is_template") == 0)
     802             :         {
     803          80 :             if (distemplate)
     804           0 :                 errorConflictingDefElem(defel, pstate);
     805          80 :             distemplate = defel;
     806             :         }
     807         464 :         else if (strcmp(defel->defname, "allow_connections") == 0)
     808             :         {
     809          78 :             if (dallowconnections)
     810           0 :                 errorConflictingDefElem(defel, pstate);
     811          78 :             dallowconnections = defel;
     812             :         }
     813         386 :         else if (strcmp(defel->defname, "connection_limit") == 0)
     814             :         {
     815           0 :             if (dconnlimit)
     816           0 :                 errorConflictingDefElem(defel, pstate);
     817           0 :             dconnlimit = defel;
     818             :         }
     819         386 :         else if (strcmp(defel->defname, "collation_version") == 0)
     820             :         {
     821          20 :             if (dcollversion)
     822           0 :                 errorConflictingDefElem(defel, pstate);
     823          20 :             dcollversion = defel;
     824             :         }
     825         366 :         else if (strcmp(defel->defname, "location") == 0)
     826             :         {
     827           0 :             ereport(WARNING,
     828             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
     829             :                      errmsg("LOCATION is not supported anymore"),
     830             :                      errhint("Consider using tablespaces instead."),
     831             :                      parser_errposition(pstate, defel->location)));
     832             :         }
     833         366 :         else if (strcmp(defel->defname, "oid") == 0)
     834             :         {
     835         182 :             dboid = defGetObjectId(defel);
     836             : 
     837             :             /*
     838             :              * We don't normally permit new databases to be created with
     839             :              * system-assigned OIDs. pg_upgrade tries to preserve database
     840             :              * OIDs, so we can't allow any database to be created with an OID
     841             :              * that might be in use in a freshly-initialized cluster created
     842             :              * by some future version. We assume all such OIDs will be from
     843             :              * the system-managed OID range.
     844             :              *
     845             :              * As an exception, however, we permit any OID to be assigned when
     846             :              * allow_system_table_mods=on (so that initdb can assign system
     847             :              * OIDs to template0 and postgres) or when performing a binary
     848             :              * upgrade (so that pg_upgrade can preserve whatever OIDs it finds
     849             :              * in the source cluster).
     850             :              */
     851         182 :             if (dboid < FirstNormalObjectId &&
     852         164 :                 !allowSystemTableMods && !IsBinaryUpgrade)
     853           0 :                 ereport(ERROR,
     854             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
     855             :                         errmsg("OIDs less than %u are reserved for system objects", FirstNormalObjectId));
     856             :         }
     857         184 :         else if (strcmp(defel->defname, "strategy") == 0)
     858             :         {
     859         184 :             if (dstrategy)
     860           0 :                 errorConflictingDefElem(defel, pstate);
     861         184 :             dstrategy = defel;
     862             :         }
     863             :         else
     864           0 :             ereport(ERROR,
     865             :                     (errcode(ERRCODE_SYNTAX_ERROR),
     866             :                      errmsg("option \"%s\" not recognized", defel->defname),
     867             :                      parser_errposition(pstate, defel->location)));
     868             :     }
     869             : 
     870         636 :     if (downer && downer->arg)
     871           2 :         dbowner = defGetString(downer);
     872         636 :     if (dtemplate && dtemplate->arg)
     873         276 :         dbtemplate = defGetString(dtemplate);
     874         636 :     if (dencoding && dencoding->arg)
     875             :     {
     876             :         const char *encoding_name;
     877             : 
     878          60 :         if (IsA(dencoding->arg, Integer))
     879             :         {
     880           0 :             encoding = defGetInt32(dencoding);
     881           0 :             encoding_name = pg_encoding_to_char(encoding);
     882           0 :             if (strcmp(encoding_name, "") == 0 ||
     883           0 :                 pg_valid_server_encoding(encoding_name) < 0)
     884           0 :                 ereport(ERROR,
     885             :                         (errcode(ERRCODE_UNDEFINED_OBJECT),
     886             :                          errmsg("%d is not a valid encoding code",
     887             :                                 encoding),
     888             :                          parser_errposition(pstate, dencoding->location)));
     889             :         }
     890             :         else
     891             :         {
     892          60 :             encoding_name = defGetString(dencoding);
     893          60 :             encoding = pg_valid_server_encoding(encoding_name);
     894          60 :             if (encoding < 0)
     895           0 :                 ereport(ERROR,
     896             :                         (errcode(ERRCODE_UNDEFINED_OBJECT),
     897             :                          errmsg("%s is not a valid encoding name",
     898             :                                 encoding_name),
     899             :                          parser_errposition(pstate, dencoding->location)));
     900             :         }
     901             :     }
     902         636 :     if (dlocale && dlocale->arg)
     903             :     {
     904          70 :         dbcollate = defGetString(dlocale);
     905          70 :         dbctype = defGetString(dlocale);
     906          70 :         dblocale = defGetString(dlocale);
     907             :     }
     908         636 :     if (dbuiltinlocale && dbuiltinlocale->arg)
     909          16 :         dblocale = defGetString(dbuiltinlocale);
     910         636 :     if (dcollate && dcollate->arg)
     911          12 :         dbcollate = defGetString(dcollate);
     912         636 :     if (dctype && dctype->arg)
     913          12 :         dbctype = defGetString(dctype);
     914         636 :     if (diculocale && diculocale->arg)
     915          10 :         dblocale = defGetString(diculocale);
     916         636 :     if (dicurules && dicurules->arg)
     917           2 :         dbicurules = defGetString(dicurules);
     918         636 :     if (dlocprovider && dlocprovider->arg)
     919             :     {
     920          76 :         char       *locproviderstr = defGetString(dlocprovider);
     921             : 
     922          76 :         if (pg_strcasecmp(locproviderstr, "builtin") == 0)
     923          30 :             dblocprovider = COLLPROVIDER_BUILTIN;
     924          46 :         else if (pg_strcasecmp(locproviderstr, "icu") == 0)
     925          16 :             dblocprovider = COLLPROVIDER_ICU;
     926          30 :         else if (pg_strcasecmp(locproviderstr, "libc") == 0)
     927          28 :             dblocprovider = COLLPROVIDER_LIBC;
     928             :         else
     929           2 :             ereport(ERROR,
     930             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
     931             :                      errmsg("unrecognized locale provider: %s",
     932             :                             locproviderstr)));
     933             :     }
     934         634 :     if (distemplate && distemplate->arg)
     935          80 :         dbistemplate = defGetBoolean(distemplate);
     936         634 :     if (dallowconnections && dallowconnections->arg)
     937          78 :         dballowconnections = defGetBoolean(dallowconnections);
     938         634 :     if (dconnlimit && dconnlimit->arg)
     939             :     {
     940           0 :         dbconnlimit = defGetInt32(dconnlimit);
     941           0 :         if (dbconnlimit < DATCONNLIMIT_UNLIMITED)
     942           0 :             ereport(ERROR,
     943             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
     944             :                      errmsg("invalid connection limit: %d", dbconnlimit)));
     945             :     }
     946         634 :     if (dcollversion)
     947          20 :         dbcollversion = defGetString(dcollversion);
     948             : 
     949             :     /* obtain OID of proposed owner */
     950         634 :     if (dbowner)
     951           2 :         datdba = get_role_oid(dbowner, false);
     952             :     else
     953         632 :         datdba = GetUserId();
     954             : 
     955             :     /*
     956             :      * To create a database, must have createdb privilege and must be able to
     957             :      * become the target role (this does not imply that the target role itself
     958             :      * must have createdb privilege).  The latter provision guards against
     959             :      * "giveaway" attacks.  Note that a superuser will always have both of
     960             :      * these privileges a fortiori.
     961             :      */
     962         634 :     if (!have_createdb_privilege())
     963           6 :         ereport(ERROR,
     964             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
     965             :                  errmsg("permission denied to create database")));
     966             : 
     967         628 :     check_can_set_role(GetUserId(), datdba);
     968             : 
     969             :     /*
     970             :      * Lookup database (template) to be cloned, and obtain share lock on it.
     971             :      * ShareLock allows two CREATE DATABASEs to work from the same template
     972             :      * concurrently, while ensuring no one is busy dropping it in parallel
     973             :      * (which would be Very Bad since we'd likely get an incomplete copy
     974             :      * without knowing it).  This also prevents any new connections from being
     975             :      * made to the source until we finish copying it, so we can be sure it
     976             :      * won't change underneath us.
     977             :      */
     978         628 :     if (!dbtemplate)
     979         354 :         dbtemplate = "template1"; /* Default template database name */
     980             : 
     981         628 :     if (!get_db_info(dbtemplate, ShareLock,
     982             :                      &src_dboid, &src_owner, &src_encoding,
     983             :                      &src_istemplate, &src_allowconn, &src_hasloginevt,
     984             :                      &src_frozenxid, &src_minmxid, &src_deftablespace,
     985             :                      &src_collate, &src_ctype, &src_locale, &src_icurules, &src_locprovider,
     986             :                      &src_collversion))
     987           0 :         ereport(ERROR,
     988             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
     989             :                  errmsg("template database \"%s\" does not exist",
     990             :                         dbtemplate)));
     991             : 
     992             :     /*
     993             :      * If the source database was in the process of being dropped, we can't
     994             :      * use it as a template.
     995             :      */
     996         628 :     if (database_is_invalid_oid(src_dboid))
     997           2 :         ereport(ERROR,
     998             :                 errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
     999             :                 errmsg("cannot use invalid database \"%s\" as template", dbtemplate),
    1000             :                 errhint("Use DROP DATABASE to drop invalid databases."));
    1001             : 
    1002             :     /*
    1003             :      * Permission check: to copy a DB that's not marked datistemplate, you
    1004             :      * must be superuser or the owner thereof.
    1005             :      */
    1006         626 :     if (!src_istemplate)
    1007             :     {
    1008          12 :         if (!object_ownercheck(DatabaseRelationId, src_dboid, GetUserId()))
    1009           0 :             ereport(ERROR,
    1010             :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    1011             :                      errmsg("permission denied to copy database \"%s\"",
    1012             :                             dbtemplate)));
    1013             :     }
    1014             : 
    1015             :     /* Validate the database creation strategy. */
    1016         626 :     if (dstrategy && dstrategy->arg)
    1017             :     {
    1018             :         char       *strategy;
    1019             : 
    1020         184 :         strategy = defGetString(dstrategy);
    1021         184 :         if (strcmp(strategy, "wal_log") == 0)
    1022          12 :             dbstrategy = CREATEDB_WAL_LOG;
    1023         172 :         else if (strcmp(strategy, "file_copy") == 0)
    1024         170 :             dbstrategy = CREATEDB_FILE_COPY;
    1025             :         else
    1026           2 :             ereport(ERROR,
    1027             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1028             :                      errmsg("invalid create database strategy \"%s\"", strategy),
    1029             :                      errhint("Valid strategies are \"wal_log\", and \"file_copy\".")));
    1030             :     }
    1031             : 
    1032             :     /* If encoding or locales are defaulted, use source's setting */
    1033         624 :     if (encoding < 0)
    1034         564 :         encoding = src_encoding;
    1035         624 :     if (dbcollate == NULL)
    1036         548 :         dbcollate = src_collate;
    1037         624 :     if (dbctype == NULL)
    1038         548 :         dbctype = src_ctype;
    1039         624 :     if (dblocprovider == '\0')
    1040         550 :         dblocprovider = src_locprovider;
    1041         624 :     if (dblocale == NULL)
    1042         546 :         dblocale = src_locale;
    1043         624 :     if (dbicurules == NULL)
    1044         622 :         dbicurules = src_icurules;
    1045             : 
    1046             :     /* Some encodings are client only */
    1047         624 :     if (!PG_VALID_BE_ENCODING(encoding))
    1048           0 :         ereport(ERROR,
    1049             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1050             :                  errmsg("invalid server encoding %d", encoding)));
    1051             : 
    1052             :     /* Check that the chosen locales are valid, and get canonical spellings */
    1053         624 :     if (!check_locale(LC_COLLATE, dbcollate, &canonname))
    1054           2 :         ereport(ERROR,
    1055             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1056             :                  errmsg("invalid LC_COLLATE locale name: \"%s\"", dbcollate),
    1057             :                  errhint("If the locale name is specific to ICU, use ICU_LOCALE.")));
    1058         622 :     dbcollate = canonname;
    1059         622 :     if (!check_locale(LC_CTYPE, dbctype, &canonname))
    1060           2 :         ereport(ERROR,
    1061             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1062             :                  errmsg("invalid LC_CTYPE locale name: \"%s\"", dbctype),
    1063             :                  errhint("If the locale name is specific to ICU, use ICU_LOCALE.")));
    1064         620 :     dbctype = canonname;
    1065             : 
    1066         620 :     check_encoding_locale_matches(encoding, dbcollate, dbctype);
    1067             : 
    1068             :     /* validate provider-specific parameters */
    1069         620 :     if (dblocprovider != COLLPROVIDER_BUILTIN)
    1070             :     {
    1071         564 :         if (dbuiltinlocale)
    1072           0 :             ereport(ERROR,
    1073             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1074             :                      errmsg("BUILTIN_LOCALE cannot be specified unless locale provider is builtin")));
    1075             :     }
    1076          56 :     else if (dblocprovider != COLLPROVIDER_ICU)
    1077             :     {
    1078          56 :         if (diculocale)
    1079           2 :             ereport(ERROR,
    1080             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1081             :                      errmsg("ICU locale cannot be specified unless locale provider is ICU")));
    1082             : 
    1083          54 :         if (dbicurules)
    1084           2 :             ereport(ERROR,
    1085             :                     (errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
    1086             :                      errmsg("ICU rules cannot be specified unless locale provider is ICU")));
    1087             :     }
    1088             : 
    1089             :     /* validate and canonicalize locale for the provider */
    1090         616 :     if (dblocprovider == COLLPROVIDER_BUILTIN)
    1091             :     {
    1092             :         /*
    1093             :          * This would happen if template0 uses the libc provider but the new
    1094             :          * database uses builtin.
    1095             :          */
    1096          52 :         if (!dblocale)
    1097           2 :             ereport(ERROR,
    1098             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1099             :                      errmsg("LOCALE or BUILTIN_LOCALE must be specified")));
    1100             : 
    1101          50 :         dblocale = builtin_validate_locale(encoding, dblocale);
    1102             :     }
    1103         564 :     else if (dblocprovider == COLLPROVIDER_ICU)
    1104             :     {
    1105          30 :         if (!(is_encoding_supported_by_icu(encoding)))
    1106           2 :             ereport(ERROR,
    1107             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1108             :                      errmsg("encoding \"%s\" is not supported with ICU provider",
    1109             :                             pg_encoding_to_char(encoding))));
    1110             : 
    1111             :         /*
    1112             :          * This would happen if template0 uses the libc provider but the new
    1113             :          * database uses icu.
    1114             :          */
    1115          28 :         if (!dblocale)
    1116           2 :             ereport(ERROR,
    1117             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1118             :                      errmsg("LOCALE or ICU_LOCALE must be specified")));
    1119             : 
    1120             :         /*
    1121             :          * During binary upgrade, or when the locale came from the template
    1122             :          * database, preserve locale string. Otherwise, canonicalize to a
    1123             :          * language tag.
    1124             :          */
    1125          26 :         if (!IsBinaryUpgrade && dblocale != src_locale)
    1126             :         {
    1127          14 :             char       *langtag = icu_language_tag(dblocale,
    1128             :                                                    icu_validation_level);
    1129             : 
    1130          14 :             if (langtag && strcmp(dblocale, langtag) != 0)
    1131             :             {
    1132           6 :                 ereport(NOTICE,
    1133             :                         (errmsg("using standard form \"%s\" for ICU locale \"%s\"",
    1134             :                                 langtag, dblocale)));
    1135             : 
    1136           6 :                 dblocale = langtag;
    1137             :             }
    1138             :         }
    1139             : 
    1140          26 :         icu_validate_locale(dblocale);
    1141             :     }
    1142             : 
    1143             :     /* for libc, locale comes from datcollate and datctype */
    1144         606 :     if (dblocprovider == COLLPROVIDER_LIBC)
    1145         534 :         dblocale = NULL;
    1146             : 
    1147             :     /*
    1148             :      * Check that the new encoding and locale settings match the source
    1149             :      * database.  We insist on this because we simply copy the source data ---
    1150             :      * any non-ASCII data would be wrongly encoded, and any indexes sorted
    1151             :      * according to the source locale would be wrong.
    1152             :      *
    1153             :      * However, we assume that template0 doesn't contain any non-ASCII data
    1154             :      * nor any indexes that depend on collation or ctype, so template0 can be
    1155             :      * used as template for creating a database with any encoding or locale.
    1156             :      */
    1157         606 :     if (strcmp(dbtemplate, "template0") != 0)
    1158             :     {
    1159         368 :         if (encoding != src_encoding)
    1160           0 :             ereport(ERROR,
    1161             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1162             :                      errmsg("new encoding (%s) is incompatible with the encoding of the template database (%s)",
    1163             :                             pg_encoding_to_char(encoding),
    1164             :                             pg_encoding_to_char(src_encoding)),
    1165             :                      errhint("Use the same encoding as in the template database, or use template0 as template.")));
    1166             : 
    1167         368 :         if (strcmp(dbcollate, src_collate) != 0)
    1168           2 :             ereport(ERROR,
    1169             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1170             :                      errmsg("new collation (%s) is incompatible with the collation of the template database (%s)",
    1171             :                             dbcollate, src_collate),
    1172             :                      errhint("Use the same collation as in the template database, or use template0 as template.")));
    1173             : 
    1174         366 :         if (strcmp(dbctype, src_ctype) != 0)
    1175           0 :             ereport(ERROR,
    1176             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1177             :                      errmsg("new LC_CTYPE (%s) is incompatible with the LC_CTYPE of the template database (%s)",
    1178             :                             dbctype, src_ctype),
    1179             :                      errhint("Use the same LC_CTYPE as in the template database, or use template0 as template.")));
    1180             : 
    1181         366 :         if (dblocprovider != src_locprovider)
    1182           0 :             ereport(ERROR,
    1183             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1184             :                      errmsg("new locale provider (%s) does not match locale provider of the template database (%s)",
    1185             :                             collprovider_name(dblocprovider), collprovider_name(src_locprovider)),
    1186             :                      errhint("Use the same locale provider as in the template database, or use template0 as template.")));
    1187             : 
    1188         366 :         if (dblocprovider == COLLPROVIDER_ICU)
    1189             :         {
    1190             :             char       *val1;
    1191             :             char       *val2;
    1192             : 
    1193             :             Assert(dblocale);
    1194             :             Assert(src_locale);
    1195          12 :             if (strcmp(dblocale, src_locale) != 0)
    1196           0 :                 ereport(ERROR,
    1197             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1198             :                          errmsg("new ICU locale (%s) is incompatible with the ICU locale of the template database (%s)",
    1199             :                                 dblocale, src_locale),
    1200             :                          errhint("Use the same ICU locale as in the template database, or use template0 as template.")));
    1201             : 
    1202          12 :             val1 = dbicurules;
    1203          12 :             if (!val1)
    1204          12 :                 val1 = "";
    1205          12 :             val2 = src_icurules;
    1206          12 :             if (!val2)
    1207          12 :                 val2 = "";
    1208          12 :             if (strcmp(val1, val2) != 0)
    1209           0 :                 ereport(ERROR,
    1210             :                         (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1211             :                          errmsg("new ICU collation rules (%s) are incompatible with the ICU collation rules of the template database (%s)",
    1212             :                                 val1, val2),
    1213             :                          errhint("Use the same ICU collation rules as in the template database, or use template0 as template.")));
    1214             :         }
    1215             :     }
    1216             : 
    1217             :     /*
    1218             :      * If we got a collation version for the template database, check that it
    1219             :      * matches the actual OS collation version.  Otherwise error; the user
    1220             :      * needs to fix the template database first.  Don't complain if a
    1221             :      * collation version was specified explicitly as a statement option; that
    1222             :      * is used by pg_upgrade to reproduce the old state exactly.
    1223             :      *
    1224             :      * (If the template database has no collation version, then either the
    1225             :      * platform/provider does not support collation versioning, or it's
    1226             :      * template0, for which we stipulate that it does not contain
    1227             :      * collation-using objects.)
    1228             :      */
    1229         604 :     if (src_collversion && !dcollversion)
    1230             :     {
    1231             :         char       *actual_versionstr;
    1232             :         const char *locale;
    1233             : 
    1234         232 :         if (dblocprovider == COLLPROVIDER_LIBC)
    1235         210 :             locale = dbcollate;
    1236             :         else
    1237          22 :             locale = dblocale;
    1238             : 
    1239         232 :         actual_versionstr = get_collation_actual_version(dblocprovider, locale);
    1240         232 :         if (!actual_versionstr)
    1241           0 :             ereport(ERROR,
    1242             :                     (errmsg("template database \"%s\" has a collation version, but no actual collation version could be determined",
    1243             :                             dbtemplate)));
    1244             : 
    1245         232 :         if (strcmp(actual_versionstr, src_collversion) != 0)
    1246           0 :             ereport(ERROR,
    1247             :                     (errmsg("template database \"%s\" has a collation version mismatch",
    1248             :                             dbtemplate),
    1249             :                      errdetail("The template database was created using collation version %s, "
    1250             :                                "but the operating system provides version %s.",
    1251             :                                src_collversion, actual_versionstr),
    1252             :                      errhint("Rebuild all objects in the template database that use the default collation and run "
    1253             :                              "ALTER DATABASE %s REFRESH COLLATION VERSION, "
    1254             :                              "or build PostgreSQL with the right library version.",
    1255             :                              quote_identifier(dbtemplate))));
    1256             :     }
    1257             : 
    1258         604 :     if (dbcollversion == NULL)
    1259         584 :         dbcollversion = src_collversion;
    1260             : 
    1261             :     /*
    1262             :      * Normally, we copy the collation version from the template database.
    1263             :      * This last resort only applies if the template database does not have a
    1264             :      * collation version, which is normally only the case for template0.
    1265             :      */
    1266         604 :     if (dbcollversion == NULL)
    1267             :     {
    1268             :         const char *locale;
    1269             : 
    1270         352 :         if (dblocprovider == COLLPROVIDER_LIBC)
    1271         316 :             locale = dbcollate;
    1272             :         else
    1273          36 :             locale = dblocale;
    1274             : 
    1275         352 :         dbcollversion = get_collation_actual_version(dblocprovider, locale);
    1276             :     }
    1277             : 
    1278             :     /* Resolve default tablespace for new database */
    1279         604 :     if (dtablespacename && dtablespacename->arg)
    1280          16 :     {
    1281             :         char       *tablespacename;
    1282             :         AclResult   aclresult;
    1283             : 
    1284          16 :         tablespacename = defGetString(dtablespacename);
    1285          16 :         dst_deftablespace = get_tablespace_oid(tablespacename, false);
    1286             :         /* check permissions */
    1287          16 :         aclresult = object_aclcheck(TableSpaceRelationId, dst_deftablespace, GetUserId(),
    1288             :                                     ACL_CREATE);
    1289          16 :         if (aclresult != ACLCHECK_OK)
    1290           0 :             aclcheck_error(aclresult, OBJECT_TABLESPACE,
    1291             :                            tablespacename);
    1292             : 
    1293             :         /* pg_global must never be the default tablespace */
    1294          16 :         if (dst_deftablespace == GLOBALTABLESPACE_OID)
    1295           0 :             ereport(ERROR,
    1296             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1297             :                      errmsg("pg_global cannot be used as default tablespace")));
    1298             : 
    1299             :         /*
    1300             :          * If we are trying to change the default tablespace of the template,
    1301             :          * we require that the template not have any files in the new default
    1302             :          * tablespace.  This is necessary because otherwise the copied
    1303             :          * database would contain pg_class rows that refer to its default
    1304             :          * tablespace both explicitly (by OID) and implicitly (as zero), which
    1305             :          * would cause problems.  For example another CREATE DATABASE using
    1306             :          * the copied database as template, and trying to change its default
    1307             :          * tablespace again, would yield outright incorrect results (it would
    1308             :          * improperly move tables to the new default tablespace that should
    1309             :          * stay in the same tablespace).
    1310             :          */
    1311          16 :         if (dst_deftablespace != src_deftablespace)
    1312             :         {
    1313             :             char       *srcpath;
    1314             :             struct stat st;
    1315             : 
    1316          16 :             srcpath = GetDatabasePath(src_dboid, dst_deftablespace);
    1317             : 
    1318          16 :             if (stat(srcpath, &st) == 0 &&
    1319           0 :                 S_ISDIR(st.st_mode) &&
    1320           0 :                 !directory_is_empty(srcpath))
    1321           0 :                 ereport(ERROR,
    1322             :                         (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1323             :                          errmsg("cannot assign new default tablespace \"%s\"",
    1324             :                                 tablespacename),
    1325             :                          errdetail("There is a conflict because database \"%s\" already has some tables in this tablespace.",
    1326             :                                    dbtemplate)));
    1327          16 :             pfree(srcpath);
    1328             :         }
    1329             :     }
    1330             :     else
    1331             :     {
    1332             :         /* Use template database's default tablespace */
    1333         588 :         dst_deftablespace = src_deftablespace;
    1334             :         /* Note there is no additional permission check in this path */
    1335             :     }
    1336             : 
    1337             :     /*
    1338             :      * If built with appropriate switch, whine when regression-testing
    1339             :      * conventions for database names are violated.  But don't complain during
    1340             :      * initdb.
    1341             :      */
    1342             : #ifdef ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
    1343             :     if (IsUnderPostmaster && strstr(dbname, "regression") == NULL)
    1344             :         elog(WARNING, "databases created by regression test cases should have names including \"regression\"");
    1345             : #endif
    1346             : 
    1347             :     /*
    1348             :      * Check for db name conflict.  This is just to give a more friendly error
    1349             :      * message than "unique index violation".  There's a race condition but
    1350             :      * we're willing to accept the less friendly message in that case.
    1351             :      */
    1352         604 :     if (OidIsValid(get_database_oid(dbname, true)))
    1353           2 :         ereport(ERROR,
    1354             :                 (errcode(ERRCODE_DUPLICATE_DATABASE),
    1355             :                  errmsg("database \"%s\" already exists", dbname)));
    1356             : 
    1357             :     /*
    1358             :      * The source DB can't have any active backends, except this one
    1359             :      * (exception is to allow CREATE DB while connected to template1).
    1360             :      * Otherwise we might copy inconsistent data.
    1361             :      *
    1362             :      * This should be last among the basic error checks, because it involves
    1363             :      * potential waiting; we may as well throw an error first if we're gonna
    1364             :      * throw one.
    1365             :      */
    1366         602 :     if (CountOtherDBBackends(src_dboid, &notherbackends, &npreparedxacts))
    1367           0 :         ereport(ERROR,
    1368             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1369             :                  errmsg("source database \"%s\" is being accessed by other users",
    1370             :                         dbtemplate),
    1371             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    1372             : 
    1373             :     /*
    1374             :      * Select an OID for the new database, checking that it doesn't have a
    1375             :      * filename conflict with anything already existing in the tablespace
    1376             :      * directories.
    1377             :      */
    1378         602 :     pg_database_rel = table_open(DatabaseRelationId, RowExclusiveLock);
    1379             : 
    1380             :     /*
    1381             :      * If database OID is configured, check if the OID is already in use or
    1382             :      * data directory already exists.
    1383             :      */
    1384         602 :     if (OidIsValid(dboid))
    1385             :     {
    1386         182 :         char       *existing_dbname = get_database_name(dboid);
    1387             : 
    1388         182 :         if (existing_dbname != NULL)
    1389           0 :             ereport(ERROR,
    1390             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
    1391             :                     errmsg("database OID %u is already in use by database \"%s\"",
    1392             :                            dboid, existing_dbname));
    1393             : 
    1394         182 :         if (check_db_file_conflict(dboid))
    1395           0 :             ereport(ERROR,
    1396             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE)),
    1397             :                     errmsg("data directory with the specified OID %u already exists", dboid));
    1398             :     }
    1399             :     else
    1400             :     {
    1401             :         /* Select an OID for the new database if is not explicitly configured. */
    1402             :         do
    1403             :         {
    1404         420 :             dboid = GetNewOidWithIndex(pg_database_rel, DatabaseOidIndexId,
    1405             :                                        Anum_pg_database_oid);
    1406         420 :         } while (check_db_file_conflict(dboid));
    1407             :     }
    1408             : 
    1409             :     /*
    1410             :      * Insert a new tuple into pg_database.  This establishes our ownership of
    1411             :      * the new database name (anyone else trying to insert the same name will
    1412             :      * block on the unique index, and fail after we commit).
    1413             :      */
    1414             : 
    1415             :     Assert((dblocprovider != COLLPROVIDER_LIBC && dblocale) ||
    1416             :            (dblocprovider == COLLPROVIDER_LIBC && !dblocale));
    1417             : 
    1418             :     /* Form tuple */
    1419         602 :     new_record[Anum_pg_database_oid - 1] = ObjectIdGetDatum(dboid);
    1420         602 :     new_record[Anum_pg_database_datname - 1] =
    1421         602 :         DirectFunctionCall1(namein, CStringGetDatum(dbname));
    1422         602 :     new_record[Anum_pg_database_datdba - 1] = ObjectIdGetDatum(datdba);
    1423         602 :     new_record[Anum_pg_database_encoding - 1] = Int32GetDatum(encoding);
    1424         602 :     new_record[Anum_pg_database_datlocprovider - 1] = CharGetDatum(dblocprovider);
    1425         602 :     new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
    1426         602 :     new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
    1427         602 :     new_record[Anum_pg_database_dathasloginevt - 1] = BoolGetDatum(src_hasloginevt);
    1428         602 :     new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
    1429         602 :     new_record[Anum_pg_database_datfrozenxid - 1] = TransactionIdGetDatum(src_frozenxid);
    1430         602 :     new_record[Anum_pg_database_datminmxid - 1] = TransactionIdGetDatum(src_minmxid);
    1431         602 :     new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_deftablespace);
    1432         602 :     new_record[Anum_pg_database_datcollate - 1] = CStringGetTextDatum(dbcollate);
    1433         602 :     new_record[Anum_pg_database_datctype - 1] = CStringGetTextDatum(dbctype);
    1434         602 :     if (dblocale)
    1435          70 :         new_record[Anum_pg_database_datlocale - 1] = CStringGetTextDatum(dblocale);
    1436             :     else
    1437         532 :         new_record_nulls[Anum_pg_database_datlocale - 1] = true;
    1438         602 :     if (dbicurules)
    1439           0 :         new_record[Anum_pg_database_daticurules - 1] = CStringGetTextDatum(dbicurules);
    1440             :     else
    1441         602 :         new_record_nulls[Anum_pg_database_daticurules - 1] = true;
    1442         602 :     if (dbcollversion)
    1443         490 :         new_record[Anum_pg_database_datcollversion - 1] = CStringGetTextDatum(dbcollversion);
    1444             :     else
    1445         112 :         new_record_nulls[Anum_pg_database_datcollversion - 1] = true;
    1446             : 
    1447             :     /*
    1448             :      * We deliberately set datacl to default (NULL), rather than copying it
    1449             :      * from the template database.  Copying it would be a bad idea when the
    1450             :      * owner is not the same as the template's owner.
    1451             :      */
    1452         602 :     new_record_nulls[Anum_pg_database_datacl - 1] = true;
    1453             : 
    1454         602 :     tuple = heap_form_tuple(RelationGetDescr(pg_database_rel),
    1455             :                             new_record, new_record_nulls);
    1456             : 
    1457         602 :     CatalogTupleInsert(pg_database_rel, tuple);
    1458             : 
    1459             :     /*
    1460             :      * Now generate additional catalog entries associated with the new DB
    1461             :      */
    1462             : 
    1463             :     /* Register owner dependency */
    1464         602 :     recordDependencyOnOwner(DatabaseRelationId, dboid, datdba);
    1465             : 
    1466             :     /* Create pg_shdepend entries for objects within database */
    1467         602 :     copyTemplateDependencies(src_dboid, dboid);
    1468             : 
    1469             :     /* Post creation hook for new database */
    1470         602 :     InvokeObjectPostCreateHook(DatabaseRelationId, dboid, 0);
    1471             : 
    1472             :     /*
    1473             :      * If we're going to be reading data for the to-be-created database into
    1474             :      * shared_buffers, take a lock on it. Nobody should know that this
    1475             :      * database exists yet, but it's good to maintain the invariant that an
    1476             :      * AccessExclusiveLock on the database is sufficient to drop all of its
    1477             :      * buffers without worrying about more being read later.
    1478             :      *
    1479             :      * Note that we need to do this before entering the
    1480             :      * PG_ENSURE_ERROR_CLEANUP block below, because createdb_failure_callback
    1481             :      * expects this lock to be held already.
    1482             :      */
    1483         602 :     if (dbstrategy == CREATEDB_WAL_LOG)
    1484         432 :         LockSharedObject(DatabaseRelationId, dboid, 0, AccessShareLock);
    1485             : 
    1486             :     /*
    1487             :      * Once we start copying subdirectories, we need to be able to clean 'em
    1488             :      * up if we fail.  Use an ENSURE block to make sure this happens.  (This
    1489             :      * is not a 100% solution, because of the possibility of failure during
    1490             :      * transaction commit after we leave this routine, but it should handle
    1491             :      * most scenarios.)
    1492             :      */
    1493         602 :     fparms.src_dboid = src_dboid;
    1494         602 :     fparms.dest_dboid = dboid;
    1495         602 :     fparms.strategy = dbstrategy;
    1496             : 
    1497         602 :     PG_ENSURE_ERROR_CLEANUP(createdb_failure_callback,
    1498             :                             PointerGetDatum(&fparms));
    1499             :     {
    1500             :         /*
    1501             :          * If the user has asked to create a database with WAL_LOG strategy
    1502             :          * then call CreateDatabaseUsingWalLog, which will copy the database
    1503             :          * at the block level and it will WAL log each copied block.
    1504             :          * Otherwise, call CreateDatabaseUsingFileCopy that will copy the
    1505             :          * database file by file.
    1506             :          */
    1507         602 :         if (dbstrategy == CREATEDB_WAL_LOG)
    1508         432 :             CreateDatabaseUsingWalLog(src_dboid, dboid, src_deftablespace,
    1509             :                                       dst_deftablespace);
    1510             :         else
    1511         170 :             CreateDatabaseUsingFileCopy(src_dboid, dboid, src_deftablespace,
    1512             :                                         dst_deftablespace);
    1513             : 
    1514             :         /*
    1515             :          * Close pg_database, but keep lock till commit.
    1516             :          */
    1517         602 :         table_close(pg_database_rel, NoLock);
    1518             : 
    1519             :         /*
    1520             :          * Force synchronous commit, thus minimizing the window between
    1521             :          * creation of the database files and committal of the transaction. If
    1522             :          * we crash before committing, we'll have a DB that's taking up disk
    1523             :          * space but is not in pg_database, which is not good.
    1524             :          */
    1525         602 :         ForceSyncCommit();
    1526             :     }
    1527         602 :     PG_END_ENSURE_ERROR_CLEANUP(createdb_failure_callback,
    1528             :                                 PointerGetDatum(&fparms));
    1529             : 
    1530         602 :     return dboid;
    1531             : }
    1532             : 
    1533             : /*
    1534             :  * Check whether chosen encoding matches chosen locale settings.  This
    1535             :  * restriction is necessary because libc's locale-specific code usually
    1536             :  * fails when presented with data in an encoding it's not expecting. We
    1537             :  * allow mismatch in four cases:
    1538             :  *
    1539             :  * 1. locale encoding = SQL_ASCII, which means that the locale is C/POSIX
    1540             :  * which works with any encoding.
    1541             :  *
    1542             :  * 2. locale encoding = -1, which means that we couldn't determine the
    1543             :  * locale's encoding and have to trust the user to get it right.
    1544             :  *
    1545             :  * 3. selected encoding is UTF8 and platform is win32. This is because
    1546             :  * UTF8 is a pseudo codepage that is supported in all locales since it's
    1547             :  * converted to UTF16 before being used.
    1548             :  *
    1549             :  * 4. selected encoding is SQL_ASCII, but only if you're a superuser. This
    1550             :  * is risky but we have historically allowed it --- notably, the
    1551             :  * regression tests require it.
    1552             :  *
    1553             :  * Note: if you change this policy, fix initdb to match.
    1554             :  */
    1555             : void
    1556         648 : check_encoding_locale_matches(int encoding, const char *collate, const char *ctype)
    1557             : {
    1558         648 :     int         ctype_encoding = pg_get_encoding_from_locale(ctype, true);
    1559         648 :     int         collate_encoding = pg_get_encoding_from_locale(collate, true);
    1560             : 
    1561         654 :     if (!(ctype_encoding == encoding ||
    1562           6 :           ctype_encoding == PG_SQL_ASCII ||
    1563             :           ctype_encoding == -1 ||
    1564             : #ifdef WIN32
    1565             :           encoding == PG_UTF8 ||
    1566             : #endif
    1567           6 :           (encoding == PG_SQL_ASCII && superuser())))
    1568           0 :         ereport(ERROR,
    1569             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1570             :                  errmsg("encoding \"%s\" does not match locale \"%s\"",
    1571             :                         pg_encoding_to_char(encoding),
    1572             :                         ctype),
    1573             :                  errdetail("The chosen LC_CTYPE setting requires encoding \"%s\".",
    1574             :                            pg_encoding_to_char(ctype_encoding))));
    1575             : 
    1576         654 :     if (!(collate_encoding == encoding ||
    1577           6 :           collate_encoding == PG_SQL_ASCII ||
    1578             :           collate_encoding == -1 ||
    1579             : #ifdef WIN32
    1580             :           encoding == PG_UTF8 ||
    1581             : #endif
    1582           6 :           (encoding == PG_SQL_ASCII && superuser())))
    1583           0 :         ereport(ERROR,
    1584             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    1585             :                  errmsg("encoding \"%s\" does not match locale \"%s\"",
    1586             :                         pg_encoding_to_char(encoding),
    1587             :                         collate),
    1588             :                  errdetail("The chosen LC_COLLATE setting requires encoding \"%s\".",
    1589             :                            pg_encoding_to_char(collate_encoding))));
    1590         648 : }
    1591             : 
    1592             : /* Error cleanup callback for createdb */
    1593             : static void
    1594           0 : createdb_failure_callback(int code, Datum arg)
    1595             : {
    1596           0 :     createdb_failure_params *fparms = (createdb_failure_params *) DatumGetPointer(arg);
    1597             : 
    1598             :     /*
    1599             :      * If we were copying database at block levels then drop pages for the
    1600             :      * destination database that are in the shared buffer cache.  And tell
    1601             :      * checkpointer to forget any pending fsync and unlink requests for files
    1602             :      * in the database.  The reasoning behind doing this is same as explained
    1603             :      * in dropdb function.  But unlike dropdb we don't need to call
    1604             :      * pgstat_drop_database because this database is still not created so
    1605             :      * there should not be any stat for this.
    1606             :      */
    1607           0 :     if (fparms->strategy == CREATEDB_WAL_LOG)
    1608             :     {
    1609           0 :         DropDatabaseBuffers(fparms->dest_dboid);
    1610           0 :         ForgetDatabaseSyncRequests(fparms->dest_dboid);
    1611             : 
    1612             :         /* Release lock on the target database. */
    1613           0 :         UnlockSharedObject(DatabaseRelationId, fparms->dest_dboid, 0,
    1614             :                            AccessShareLock);
    1615             :     }
    1616             : 
    1617             :     /*
    1618             :      * Release lock on source database before doing recursive remove. This is
    1619             :      * not essential but it seems desirable to release the lock as soon as
    1620             :      * possible.
    1621             :      */
    1622           0 :     UnlockSharedObject(DatabaseRelationId, fparms->src_dboid, 0, ShareLock);
    1623             : 
    1624             :     /* Throw away any successfully copied subdirectories */
    1625           0 :     remove_dbtablespaces(fparms->dest_dboid);
    1626           0 : }
    1627             : 
    1628             : 
    1629             : /*
    1630             :  * DROP DATABASE
    1631             :  */
    1632             : void
    1633          94 : dropdb(const char *dbname, bool missing_ok, bool force)
    1634             : {
    1635             :     Oid         db_id;
    1636             :     bool        db_istemplate;
    1637             :     Relation    pgdbrel;
    1638             :     HeapTuple   tup;
    1639             :     Form_pg_database datform;
    1640             :     int         notherbackends;
    1641             :     int         npreparedxacts;
    1642             :     int         nslots,
    1643             :                 nslots_active;
    1644             :     int         nsubscriptions;
    1645             : 
    1646             :     /*
    1647             :      * Look up the target database's OID, and get exclusive lock on it. We
    1648             :      * need this to ensure that no new backend starts up in the target
    1649             :      * database while we are deleting it (see postinit.c), and that no one is
    1650             :      * using it as a CREATE DATABASE template or trying to delete it for
    1651             :      * themselves.
    1652             :      */
    1653          94 :     pgdbrel = table_open(DatabaseRelationId, RowExclusiveLock);
    1654             : 
    1655          94 :     if (!get_db_info(dbname, AccessExclusiveLock, &db_id, NULL, NULL,
    1656             :                      &db_istemplate, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL))
    1657             :     {
    1658          32 :         if (!missing_ok)
    1659             :         {
    1660          16 :             ereport(ERROR,
    1661             :                     (errcode(ERRCODE_UNDEFINED_DATABASE),
    1662             :                      errmsg("database \"%s\" does not exist", dbname)));
    1663             :         }
    1664             :         else
    1665             :         {
    1666             :             /* Close pg_database, release the lock, since we changed nothing */
    1667          16 :             table_close(pgdbrel, RowExclusiveLock);
    1668          16 :             ereport(NOTICE,
    1669             :                     (errmsg("database \"%s\" does not exist, skipping",
    1670             :                             dbname)));
    1671          16 :             return;
    1672             :         }
    1673             :     }
    1674             : 
    1675             :     /*
    1676             :      * Permission checks
    1677             :      */
    1678          62 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    1679           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    1680             :                        dbname);
    1681             : 
    1682             :     /* DROP hook for the database being removed */
    1683          62 :     InvokeObjectDropHook(DatabaseRelationId, db_id, 0);
    1684             : 
    1685             :     /*
    1686             :      * Disallow dropping a DB that is marked istemplate.  This is just to
    1687             :      * prevent people from accidentally dropping template0 or template1; they
    1688             :      * can do so if they're really determined ...
    1689             :      */
    1690          62 :     if (db_istemplate)
    1691           0 :         ereport(ERROR,
    1692             :                 (errcode(ERRCODE_WRONG_OBJECT_TYPE),
    1693             :                  errmsg("cannot drop a template database")));
    1694             : 
    1695             :     /* Obviously can't drop my own database */
    1696          62 :     if (db_id == MyDatabaseId)
    1697           0 :         ereport(ERROR,
    1698             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1699             :                  errmsg("cannot drop the currently open database")));
    1700             : 
    1701             :     /*
    1702             :      * Check whether there are active logical slots that refer to the
    1703             :      * to-be-dropped database. The database lock we are holding prevents the
    1704             :      * creation of new slots using the database or existing slots becoming
    1705             :      * active.
    1706             :      */
    1707          62 :     (void) ReplicationSlotsCountDBSlots(db_id, &nslots, &nslots_active);
    1708          62 :     if (nslots_active)
    1709             :     {
    1710           2 :         ereport(ERROR,
    1711             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1712             :                  errmsg("database \"%s\" is used by an active logical replication slot",
    1713             :                         dbname),
    1714             :                  errdetail_plural("There is %d active slot.",
    1715             :                                   "There are %d active slots.",
    1716             :                                   nslots_active, nslots_active)));
    1717             :     }
    1718             : 
    1719             :     /*
    1720             :      * Check if there are subscriptions defined in the target database.
    1721             :      *
    1722             :      * We can't drop them automatically because they might be holding
    1723             :      * resources in other databases/instances.
    1724             :      */
    1725          60 :     if ((nsubscriptions = CountDBSubscriptions(db_id)) > 0)
    1726           0 :         ereport(ERROR,
    1727             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1728             :                  errmsg("database \"%s\" is being used by logical replication subscription",
    1729             :                         dbname),
    1730             :                  errdetail_plural("There is %d subscription.",
    1731             :                                   "There are %d subscriptions.",
    1732             :                                   nsubscriptions, nsubscriptions)));
    1733             : 
    1734             : 
    1735             :     /*
    1736             :      * Attempt to terminate all existing connections to the target database if
    1737             :      * the user has requested to do so.
    1738             :      */
    1739          60 :     if (force)
    1740           2 :         TerminateOtherDBBackends(db_id);
    1741             : 
    1742             :     /*
    1743             :      * Check for other backends in the target database.  (Because we hold the
    1744             :      * database lock, no new ones can start after this.)
    1745             :      *
    1746             :      * As in CREATE DATABASE, check this after other error conditions.
    1747             :      */
    1748          60 :     if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
    1749           0 :         ereport(ERROR,
    1750             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1751             :                  errmsg("database \"%s\" is being accessed by other users",
    1752             :                         dbname),
    1753             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    1754             : 
    1755             :     /*
    1756             :      * Delete any comments or security labels associated with the database.
    1757             :      */
    1758          60 :     DeleteSharedComments(db_id, DatabaseRelationId);
    1759          60 :     DeleteSharedSecurityLabel(db_id, DatabaseRelationId);
    1760             : 
    1761             :     /*
    1762             :      * Remove settings associated with this database
    1763             :      */
    1764          60 :     DropSetting(db_id, InvalidOid);
    1765             : 
    1766             :     /*
    1767             :      * Remove shared dependency references for the database.
    1768             :      */
    1769          60 :     dropDatabaseDependencies(db_id);
    1770             : 
    1771             :     /*
    1772             :      * Tell the cumulative stats system to forget it immediately, too.
    1773             :      */
    1774          60 :     pgstat_drop_database(db_id);
    1775             : 
    1776          60 :     tup = SearchSysCacheCopy1(DATABASEOID, ObjectIdGetDatum(db_id));
    1777          60 :     if (!HeapTupleIsValid(tup))
    1778           0 :         elog(ERROR, "cache lookup failed for database %u", db_id);
    1779          60 :     datform = (Form_pg_database) GETSTRUCT(tup);
    1780             : 
    1781             :     /*
    1782             :      * Except for the deletion of the catalog row, subsequent actions are not
    1783             :      * transactional (consider DropDatabaseBuffers() discarding modified
    1784             :      * buffers). But we might crash or get interrupted below. To prevent
    1785             :      * accesses to a database with invalid contents, mark the database as
    1786             :      * invalid using an in-place update.
    1787             :      *
    1788             :      * We need to flush the WAL before continuing, to guarantee the
    1789             :      * modification is durable before performing irreversible filesystem
    1790             :      * operations.
    1791             :      */
    1792          60 :     datform->datconnlimit = DATCONNLIMIT_INVALID_DB;
    1793          60 :     heap_inplace_update(pgdbrel, tup);
    1794          60 :     XLogFlush(XactLastRecEnd);
    1795             : 
    1796             :     /*
    1797             :      * Also delete the tuple - transactionally. If this transaction commits,
    1798             :      * the row will be gone, but if we fail, dropdb() can be invoked again.
    1799             :      */
    1800          60 :     CatalogTupleDelete(pgdbrel, &tup->t_self);
    1801             : 
    1802             :     /*
    1803             :      * Drop db-specific replication slots.
    1804             :      */
    1805          60 :     ReplicationSlotsDropDBSlots(db_id);
    1806             : 
    1807             :     /*
    1808             :      * Drop pages for this database that are in the shared buffer cache. This
    1809             :      * is important to ensure that no remaining backend tries to write out a
    1810             :      * dirty buffer to the dead database later...
    1811             :      */
    1812          60 :     DropDatabaseBuffers(db_id);
    1813             : 
    1814             :     /*
    1815             :      * Tell checkpointer to forget any pending fsync and unlink requests for
    1816             :      * files in the database; else the fsyncs will fail at next checkpoint, or
    1817             :      * worse, it will delete files that belong to a newly created database
    1818             :      * with the same OID.
    1819             :      */
    1820          60 :     ForgetDatabaseSyncRequests(db_id);
    1821             : 
    1822             :     /*
    1823             :      * Force a checkpoint to make sure the checkpointer has received the
    1824             :      * message sent by ForgetDatabaseSyncRequests.
    1825             :      */
    1826          60 :     RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
    1827             : 
    1828             :     /* Close all smgr fds in all backends. */
    1829          60 :     WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    1830             : 
    1831             :     /*
    1832             :      * Remove all tablespace subdirs belonging to the database.
    1833             :      */
    1834          60 :     remove_dbtablespaces(db_id);
    1835             : 
    1836             :     /*
    1837             :      * Close pg_database, but keep lock till commit.
    1838             :      */
    1839          60 :     table_close(pgdbrel, NoLock);
    1840             : 
    1841             :     /*
    1842             :      * Force synchronous commit, thus minimizing the window between removal of
    1843             :      * the database files and committal of the transaction. If we crash before
    1844             :      * committing, we'll have a DB that's gone on disk but still there
    1845             :      * according to pg_database, which is not good.
    1846             :      */
    1847          60 :     ForceSyncCommit();
    1848             : }
    1849             : 
    1850             : 
    1851             : /*
    1852             :  * Rename database
    1853             :  */
    1854             : ObjectAddress
    1855           0 : RenameDatabase(const char *oldname, const char *newname)
    1856             : {
    1857             :     Oid         db_id;
    1858             :     HeapTuple   newtup;
    1859             :     Relation    rel;
    1860             :     int         notherbackends;
    1861             :     int         npreparedxacts;
    1862             :     ObjectAddress address;
    1863             : 
    1864             :     /*
    1865             :      * Look up the target database's OID, and get exclusive lock on it. We
    1866             :      * need this for the same reasons as DROP DATABASE.
    1867             :      */
    1868           0 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    1869             : 
    1870           0 :     if (!get_db_info(oldname, AccessExclusiveLock, &db_id, NULL, NULL, NULL,
    1871             :                      NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL))
    1872           0 :         ereport(ERROR,
    1873             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    1874             :                  errmsg("database \"%s\" does not exist", oldname)));
    1875             : 
    1876             :     /* must be owner */
    1877           0 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    1878           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    1879             :                        oldname);
    1880             : 
    1881             :     /* must have createdb rights */
    1882           0 :     if (!have_createdb_privilege())
    1883           0 :         ereport(ERROR,
    1884             :                 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    1885             :                  errmsg("permission denied to rename database")));
    1886             : 
    1887             :     /*
    1888             :      * If built with appropriate switch, whine when regression-testing
    1889             :      * conventions for database names are violated.
    1890             :      */
    1891             : #ifdef ENFORCE_REGRESSION_TEST_NAME_RESTRICTIONS
    1892             :     if (strstr(newname, "regression") == NULL)
    1893             :         elog(WARNING, "databases created by regression test cases should have names including \"regression\"");
    1894             : #endif
    1895             : 
    1896             :     /*
    1897             :      * Make sure the new name doesn't exist.  See notes for same error in
    1898             :      * CREATE DATABASE.
    1899             :      */
    1900           0 :     if (OidIsValid(get_database_oid(newname, true)))
    1901           0 :         ereport(ERROR,
    1902             :                 (errcode(ERRCODE_DUPLICATE_DATABASE),
    1903             :                  errmsg("database \"%s\" already exists", newname)));
    1904             : 
    1905             :     /*
    1906             :      * XXX Client applications probably store the current database somewhere,
    1907             :      * so renaming it could cause confusion.  On the other hand, there may not
    1908             :      * be an actual problem besides a little confusion, so think about this
    1909             :      * and decide.
    1910             :      */
    1911           0 :     if (db_id == MyDatabaseId)
    1912           0 :         ereport(ERROR,
    1913             :                 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    1914             :                  errmsg("current database cannot be renamed")));
    1915             : 
    1916             :     /*
    1917             :      * Make sure the database does not have active sessions.  This is the same
    1918             :      * concern as above, but applied to other sessions.
    1919             :      *
    1920             :      * As in CREATE DATABASE, check this after other error conditions.
    1921             :      */
    1922           0 :     if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
    1923           0 :         ereport(ERROR,
    1924             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    1925             :                  errmsg("database \"%s\" is being accessed by other users",
    1926             :                         oldname),
    1927             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    1928             : 
    1929             :     /* rename */
    1930           0 :     newtup = SearchSysCacheCopy1(DATABASEOID, ObjectIdGetDatum(db_id));
    1931           0 :     if (!HeapTupleIsValid(newtup))
    1932           0 :         elog(ERROR, "cache lookup failed for database %u", db_id);
    1933           0 :     namestrcpy(&(((Form_pg_database) GETSTRUCT(newtup))->datname), newname);
    1934           0 :     CatalogTupleUpdate(rel, &newtup->t_self, newtup);
    1935             : 
    1936           0 :     InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    1937             : 
    1938           0 :     ObjectAddressSet(address, DatabaseRelationId, db_id);
    1939             : 
    1940             :     /*
    1941             :      * Close pg_database, but keep lock till commit.
    1942             :      */
    1943           0 :     table_close(rel, NoLock);
    1944             : 
    1945           0 :     return address;
    1946             : }
    1947             : 
    1948             : 
    1949             : /*
    1950             :  * ALTER DATABASE SET TABLESPACE
    1951             :  */
    1952             : static void
    1953          10 : movedb(const char *dbname, const char *tblspcname)
    1954             : {
    1955             :     Oid         db_id;
    1956             :     Relation    pgdbrel;
    1957             :     int         notherbackends;
    1958             :     int         npreparedxacts;
    1959             :     HeapTuple   oldtuple,
    1960             :                 newtuple;
    1961             :     Oid         src_tblspcoid,
    1962             :                 dst_tblspcoid;
    1963             :     ScanKeyData scankey;
    1964             :     SysScanDesc sysscan;
    1965             :     AclResult   aclresult;
    1966             :     char       *src_dbpath;
    1967             :     char       *dst_dbpath;
    1968             :     DIR        *dstdir;
    1969             :     struct dirent *xlde;
    1970             :     movedb_failure_params fparms;
    1971             : 
    1972             :     /*
    1973             :      * Look up the target database's OID, and get exclusive lock on it. We
    1974             :      * need this to ensure that no new backend starts up in the database while
    1975             :      * we are moving it, and that no one is using it as a CREATE DATABASE
    1976             :      * template or trying to delete it.
    1977             :      */
    1978          10 :     pgdbrel = table_open(DatabaseRelationId, RowExclusiveLock);
    1979             : 
    1980          10 :     if (!get_db_info(dbname, AccessExclusiveLock, &db_id, NULL, NULL, NULL,
    1981             :                      NULL, NULL, NULL, NULL, &src_tblspcoid, NULL, NULL, NULL, NULL, NULL, NULL))
    1982           0 :         ereport(ERROR,
    1983             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    1984             :                  errmsg("database \"%s\" does not exist", dbname)));
    1985             : 
    1986             :     /*
    1987             :      * We actually need a session lock, so that the lock will persist across
    1988             :      * the commit/restart below.  (We could almost get away with letting the
    1989             :      * lock be released at commit, except that someone could try to move
    1990             :      * relations of the DB back into the old directory while we rmtree() it.)
    1991             :      */
    1992          10 :     LockSharedObjectForSession(DatabaseRelationId, db_id, 0,
    1993             :                                AccessExclusiveLock);
    1994             : 
    1995             :     /*
    1996             :      * Permission checks
    1997             :      */
    1998          10 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    1999           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2000             :                        dbname);
    2001             : 
    2002             :     /*
    2003             :      * Obviously can't move the tables of my own database
    2004             :      */
    2005          10 :     if (db_id == MyDatabaseId)
    2006           0 :         ereport(ERROR,
    2007             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    2008             :                  errmsg("cannot change the tablespace of the currently open database")));
    2009             : 
    2010             :     /*
    2011             :      * Get tablespace's oid
    2012             :      */
    2013          10 :     dst_tblspcoid = get_tablespace_oid(tblspcname, false);
    2014             : 
    2015             :     /*
    2016             :      * Permission checks
    2017             :      */
    2018          10 :     aclresult = object_aclcheck(TableSpaceRelationId, dst_tblspcoid, GetUserId(),
    2019             :                                 ACL_CREATE);
    2020          10 :     if (aclresult != ACLCHECK_OK)
    2021           0 :         aclcheck_error(aclresult, OBJECT_TABLESPACE,
    2022             :                        tblspcname);
    2023             : 
    2024             :     /*
    2025             :      * pg_global must never be the default tablespace
    2026             :      */
    2027          10 :     if (dst_tblspcoid == GLOBALTABLESPACE_OID)
    2028           0 :         ereport(ERROR,
    2029             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    2030             :                  errmsg("pg_global cannot be used as default tablespace")));
    2031             : 
    2032             :     /*
    2033             :      * No-op if same tablespace
    2034             :      */
    2035          10 :     if (src_tblspcoid == dst_tblspcoid)
    2036             :     {
    2037           0 :         table_close(pgdbrel, NoLock);
    2038           0 :         UnlockSharedObjectForSession(DatabaseRelationId, db_id, 0,
    2039             :                                      AccessExclusiveLock);
    2040           0 :         return;
    2041             :     }
    2042             : 
    2043             :     /*
    2044             :      * Check for other backends in the target database.  (Because we hold the
    2045             :      * database lock, no new ones can start after this.)
    2046             :      *
    2047             :      * As in CREATE DATABASE, check this after other error conditions.
    2048             :      */
    2049          10 :     if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
    2050           0 :         ereport(ERROR,
    2051             :                 (errcode(ERRCODE_OBJECT_IN_USE),
    2052             :                  errmsg("database \"%s\" is being accessed by other users",
    2053             :                         dbname),
    2054             :                  errdetail_busy_db(notherbackends, npreparedxacts)));
    2055             : 
    2056             :     /*
    2057             :      * Get old and new database paths
    2058             :      */
    2059          10 :     src_dbpath = GetDatabasePath(db_id, src_tblspcoid);
    2060          10 :     dst_dbpath = GetDatabasePath(db_id, dst_tblspcoid);
    2061             : 
    2062             :     /*
    2063             :      * Force a checkpoint before proceeding. This will force all dirty
    2064             :      * buffers, including those of unlogged tables, out to disk, to ensure
    2065             :      * source database is up-to-date on disk for the copy.
    2066             :      * FlushDatabaseBuffers() would suffice for that, but we also want to
    2067             :      * process any pending unlink requests. Otherwise, the check for existing
    2068             :      * files in the target directory might fail unnecessarily, not to mention
    2069             :      * that the copy might fail due to source files getting deleted under it.
    2070             :      * On Windows, this also ensures that background procs don't hold any open
    2071             :      * files, which would cause rmdir() to fail.
    2072             :      */
    2073          10 :     RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT
    2074             :                       | CHECKPOINT_FLUSH_ALL);
    2075             : 
    2076             :     /* Close all smgr fds in all backends. */
    2077          10 :     WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    2078             : 
    2079             :     /*
    2080             :      * Now drop all buffers holding data of the target database; they should
    2081             :      * no longer be dirty so DropDatabaseBuffers is safe.
    2082             :      *
    2083             :      * It might seem that we could just let these buffers age out of shared
    2084             :      * buffers naturally, since they should not get referenced anymore.  The
    2085             :      * problem with that is that if the user later moves the database back to
    2086             :      * its original tablespace, any still-surviving buffers would appear to
    2087             :      * contain valid data again --- but they'd be missing any changes made in
    2088             :      * the database while it was in the new tablespace.  In any case, freeing
    2089             :      * buffers that should never be used again seems worth the cycles.
    2090             :      *
    2091             :      * Note: it'd be sufficient to get rid of buffers matching db_id and
    2092             :      * src_tblspcoid, but bufmgr.c presently provides no API for that.
    2093             :      */
    2094          10 :     DropDatabaseBuffers(db_id);
    2095             : 
    2096             :     /*
    2097             :      * Check for existence of files in the target directory, i.e., objects of
    2098             :      * this database that are already in the target tablespace.  We can't
    2099             :      * allow the move in such a case, because we would need to change those
    2100             :      * relations' pg_class.reltablespace entries to zero, and we don't have
    2101             :      * access to the DB's pg_class to do so.
    2102             :      */
    2103          10 :     dstdir = AllocateDir(dst_dbpath);
    2104          10 :     if (dstdir != NULL)
    2105             :     {
    2106           0 :         while ((xlde = ReadDir(dstdir, dst_dbpath)) != NULL)
    2107             :         {
    2108           0 :             if (strcmp(xlde->d_name, ".") == 0 ||
    2109           0 :                 strcmp(xlde->d_name, "..") == 0)
    2110           0 :                 continue;
    2111             : 
    2112           0 :             ereport(ERROR,
    2113             :                     (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
    2114             :                      errmsg("some relations of database \"%s\" are already in tablespace \"%s\"",
    2115             :                             dbname, tblspcname),
    2116             :                      errhint("You must move them back to the database's default tablespace before using this command.")));
    2117             :         }
    2118             : 
    2119           0 :         FreeDir(dstdir);
    2120             : 
    2121             :         /*
    2122             :          * The directory exists but is empty. We must remove it before using
    2123             :          * the copydir function.
    2124             :          */
    2125           0 :         if (rmdir(dst_dbpath) != 0)
    2126           0 :             elog(ERROR, "could not remove directory \"%s\": %m",
    2127             :                  dst_dbpath);
    2128             :     }
    2129             : 
    2130             :     /*
    2131             :      * Use an ENSURE block to make sure we remove the debris if the copy fails
    2132             :      * (eg, due to out-of-disk-space).  This is not a 100% solution, because
    2133             :      * of the possibility of failure during transaction commit, but it should
    2134             :      * handle most scenarios.
    2135             :      */
    2136          10 :     fparms.dest_dboid = db_id;
    2137          10 :     fparms.dest_tsoid = dst_tblspcoid;
    2138          10 :     PG_ENSURE_ERROR_CLEANUP(movedb_failure_callback,
    2139             :                             PointerGetDatum(&fparms));
    2140             :     {
    2141          10 :         Datum       new_record[Natts_pg_database] = {0};
    2142          10 :         bool        new_record_nulls[Natts_pg_database] = {0};
    2143          10 :         bool        new_record_repl[Natts_pg_database] = {0};
    2144             : 
    2145             :         /*
    2146             :          * Copy files from the old tablespace to the new one
    2147             :          */
    2148          10 :         copydir(src_dbpath, dst_dbpath, false);
    2149             : 
    2150             :         /*
    2151             :          * Record the filesystem change in XLOG
    2152             :          */
    2153             :         {
    2154             :             xl_dbase_create_file_copy_rec xlrec;
    2155             : 
    2156          10 :             xlrec.db_id = db_id;
    2157          10 :             xlrec.tablespace_id = dst_tblspcoid;
    2158          10 :             xlrec.src_db_id = db_id;
    2159          10 :             xlrec.src_tablespace_id = src_tblspcoid;
    2160             : 
    2161          10 :             XLogBeginInsert();
    2162          10 :             XLogRegisterData((char *) &xlrec,
    2163             :                              sizeof(xl_dbase_create_file_copy_rec));
    2164             : 
    2165          10 :             (void) XLogInsert(RM_DBASE_ID,
    2166             :                               XLOG_DBASE_CREATE_FILE_COPY | XLR_SPECIAL_REL_UPDATE);
    2167             :         }
    2168             : 
    2169             :         /*
    2170             :          * Update the database's pg_database tuple
    2171             :          */
    2172          10 :         ScanKeyInit(&scankey,
    2173             :                     Anum_pg_database_datname,
    2174             :                     BTEqualStrategyNumber, F_NAMEEQ,
    2175             :                     CStringGetDatum(dbname));
    2176          10 :         sysscan = systable_beginscan(pgdbrel, DatabaseNameIndexId, true,
    2177             :                                      NULL, 1, &scankey);
    2178          10 :         oldtuple = systable_getnext(sysscan);
    2179          10 :         if (!HeapTupleIsValid(oldtuple))    /* shouldn't happen... */
    2180           0 :             ereport(ERROR,
    2181             :                     (errcode(ERRCODE_UNDEFINED_DATABASE),
    2182             :                      errmsg("database \"%s\" does not exist", dbname)));
    2183             : 
    2184          10 :         new_record[Anum_pg_database_dattablespace - 1] = ObjectIdGetDatum(dst_tblspcoid);
    2185          10 :         new_record_repl[Anum_pg_database_dattablespace - 1] = true;
    2186             : 
    2187          10 :         newtuple = heap_modify_tuple(oldtuple, RelationGetDescr(pgdbrel),
    2188             :                                      new_record,
    2189             :                                      new_record_nulls, new_record_repl);
    2190          10 :         CatalogTupleUpdate(pgdbrel, &oldtuple->t_self, newtuple);
    2191             : 
    2192          10 :         InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    2193             : 
    2194          10 :         systable_endscan(sysscan);
    2195             : 
    2196             :         /*
    2197             :          * Force another checkpoint here.  As in CREATE DATABASE, this is to
    2198             :          * ensure that we don't have to replay a committed
    2199             :          * XLOG_DBASE_CREATE_FILE_COPY operation, which would cause us to lose
    2200             :          * any unlogged operations done in the new DB tablespace before the
    2201             :          * next checkpoint.
    2202             :          */
    2203          10 :         RequestCheckpoint(CHECKPOINT_IMMEDIATE | CHECKPOINT_FORCE | CHECKPOINT_WAIT);
    2204             : 
    2205             :         /*
    2206             :          * Force synchronous commit, thus minimizing the window between
    2207             :          * copying the database files and committal of the transaction. If we
    2208             :          * crash before committing, we'll leave an orphaned set of files on
    2209             :          * disk, which is not fatal but not good either.
    2210             :          */
    2211          10 :         ForceSyncCommit();
    2212             : 
    2213             :         /*
    2214             :          * Close pg_database, but keep lock till commit.
    2215             :          */
    2216          10 :         table_close(pgdbrel, NoLock);
    2217             :     }
    2218          10 :     PG_END_ENSURE_ERROR_CLEANUP(movedb_failure_callback,
    2219             :                                 PointerGetDatum(&fparms));
    2220             : 
    2221             :     /*
    2222             :      * Commit the transaction so that the pg_database update is committed. If
    2223             :      * we crash while removing files, the database won't be corrupt, we'll
    2224             :      * just leave some orphaned files in the old directory.
    2225             :      *
    2226             :      * (This is OK because we know we aren't inside a transaction block.)
    2227             :      *
    2228             :      * XXX would it be safe/better to do this inside the ensure block?  Not
    2229             :      * convinced it's a good idea; consider elog just after the transaction
    2230             :      * really commits.
    2231             :      */
    2232          10 :     PopActiveSnapshot();
    2233          10 :     CommitTransactionCommand();
    2234             : 
    2235             :     /* Start new transaction for the remaining work; don't need a snapshot */
    2236          10 :     StartTransactionCommand();
    2237             : 
    2238             :     /*
    2239             :      * Remove files from the old tablespace
    2240             :      */
    2241          10 :     if (!rmtree(src_dbpath, true))
    2242           0 :         ereport(WARNING,
    2243             :                 (errmsg("some useless files may be left behind in old database directory \"%s\"",
    2244             :                         src_dbpath)));
    2245             : 
    2246             :     /*
    2247             :      * Record the filesystem change in XLOG
    2248             :      */
    2249             :     {
    2250             :         xl_dbase_drop_rec xlrec;
    2251             : 
    2252          10 :         xlrec.db_id = db_id;
    2253          10 :         xlrec.ntablespaces = 1;
    2254             : 
    2255          10 :         XLogBeginInsert();
    2256          10 :         XLogRegisterData((char *) &xlrec, sizeof(xl_dbase_drop_rec));
    2257          10 :         XLogRegisterData((char *) &src_tblspcoid, sizeof(Oid));
    2258             : 
    2259          10 :         (void) XLogInsert(RM_DBASE_ID,
    2260             :                           XLOG_DBASE_DROP | XLR_SPECIAL_REL_UPDATE);
    2261             :     }
    2262             : 
    2263             :     /* Now it's safe to release the database lock */
    2264          10 :     UnlockSharedObjectForSession(DatabaseRelationId, db_id, 0,
    2265             :                                  AccessExclusiveLock);
    2266             : 
    2267          10 :     pfree(src_dbpath);
    2268          10 :     pfree(dst_dbpath);
    2269             : }
    2270             : 
    2271             : /* Error cleanup callback for movedb */
    2272             : static void
    2273           0 : movedb_failure_callback(int code, Datum arg)
    2274             : {
    2275           0 :     movedb_failure_params *fparms = (movedb_failure_params *) DatumGetPointer(arg);
    2276             :     char       *dstpath;
    2277             : 
    2278             :     /* Get rid of anything we managed to copy to the target directory */
    2279           0 :     dstpath = GetDatabasePath(fparms->dest_dboid, fparms->dest_tsoid);
    2280             : 
    2281           0 :     (void) rmtree(dstpath, true);
    2282             : 
    2283           0 :     pfree(dstpath);
    2284           0 : }
    2285             : 
    2286             : /*
    2287             :  * Process options and call dropdb function.
    2288             :  */
    2289             : void
    2290          94 : DropDatabase(ParseState *pstate, DropdbStmt *stmt)
    2291             : {
    2292          94 :     bool        force = false;
    2293             :     ListCell   *lc;
    2294             : 
    2295         120 :     foreach(lc, stmt->options)
    2296             :     {
    2297          26 :         DefElem    *opt = (DefElem *) lfirst(lc);
    2298             : 
    2299          26 :         if (strcmp(opt->defname, "force") == 0)
    2300          26 :             force = true;
    2301             :         else
    2302           0 :             ereport(ERROR,
    2303             :                     (errcode(ERRCODE_SYNTAX_ERROR),
    2304             :                      errmsg("unrecognized DROP DATABASE option \"%s\"", opt->defname),
    2305             :                      parser_errposition(pstate, opt->location)));
    2306             :     }
    2307             : 
    2308          94 :     dropdb(stmt->dbname, stmt->missing_ok, force);
    2309          76 : }
    2310             : 
    2311             : /*
    2312             :  * ALTER DATABASE name ...
    2313             :  */
    2314             : Oid
    2315          34 : AlterDatabase(ParseState *pstate, AlterDatabaseStmt *stmt, bool isTopLevel)
    2316             : {
    2317             :     Relation    rel;
    2318             :     Oid         dboid;
    2319             :     HeapTuple   tuple,
    2320             :                 newtuple;
    2321             :     Form_pg_database datform;
    2322             :     ScanKeyData scankey;
    2323             :     SysScanDesc scan;
    2324             :     ListCell   *option;
    2325          34 :     bool        dbistemplate = false;
    2326          34 :     bool        dballowconnections = true;
    2327          34 :     int         dbconnlimit = DATCONNLIMIT_UNLIMITED;
    2328          34 :     DefElem    *distemplate = NULL;
    2329          34 :     DefElem    *dallowconnections = NULL;
    2330          34 :     DefElem    *dconnlimit = NULL;
    2331          34 :     DefElem    *dtablespace = NULL;
    2332          34 :     Datum       new_record[Natts_pg_database] = {0};
    2333          34 :     bool        new_record_nulls[Natts_pg_database] = {0};
    2334          34 :     bool        new_record_repl[Natts_pg_database] = {0};
    2335             : 
    2336             :     /* Extract options from the statement node tree */
    2337          68 :     foreach(option, stmt->options)
    2338             :     {
    2339          34 :         DefElem    *defel = (DefElem *) lfirst(option);
    2340             : 
    2341          34 :         if (strcmp(defel->defname, "is_template") == 0)
    2342             :         {
    2343          10 :             if (distemplate)
    2344           0 :                 errorConflictingDefElem(defel, pstate);
    2345          10 :             distemplate = defel;
    2346             :         }
    2347          24 :         else if (strcmp(defel->defname, "allow_connections") == 0)
    2348             :         {
    2349          12 :             if (dallowconnections)
    2350           0 :                 errorConflictingDefElem(defel, pstate);
    2351          12 :             dallowconnections = defel;
    2352             :         }
    2353          12 :         else if (strcmp(defel->defname, "connection_limit") == 0)
    2354             :         {
    2355           2 :             if (dconnlimit)
    2356           0 :                 errorConflictingDefElem(defel, pstate);
    2357           2 :             dconnlimit = defel;
    2358             :         }
    2359          10 :         else if (strcmp(defel->defname, "tablespace") == 0)
    2360             :         {
    2361          10 :             if (dtablespace)
    2362           0 :                 errorConflictingDefElem(defel, pstate);
    2363          10 :             dtablespace = defel;
    2364             :         }
    2365             :         else
    2366           0 :             ereport(ERROR,
    2367             :                     (errcode(ERRCODE_SYNTAX_ERROR),
    2368             :                      errmsg("option \"%s\" not recognized", defel->defname),
    2369             :                      parser_errposition(pstate, defel->location)));
    2370             :     }
    2371             : 
    2372          34 :     if (dtablespace)
    2373             :     {
    2374             :         /*
    2375             :          * While the SET TABLESPACE syntax doesn't allow any other options,
    2376             :          * somebody could write "WITH TABLESPACE ...".  Forbid any other
    2377             :          * options from being specified in that case.
    2378             :          */
    2379          10 :         if (list_length(stmt->options) != 1)
    2380           0 :             ereport(ERROR,
    2381             :                     (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
    2382             :                      errmsg("option \"%s\" cannot be specified with other options",
    2383             :                             dtablespace->defname),
    2384             :                      parser_errposition(pstate, dtablespace->location)));
    2385             :         /* this case isn't allowed within a transaction block */
    2386          10 :         PreventInTransactionBlock(isTopLevel, "ALTER DATABASE SET TABLESPACE");
    2387          10 :         movedb(stmt->dbname, defGetString(dtablespace));
    2388          10 :         return InvalidOid;
    2389             :     }
    2390             : 
    2391          24 :     if (distemplate && distemplate->arg)
    2392          10 :         dbistemplate = defGetBoolean(distemplate);
    2393          24 :     if (dallowconnections && dallowconnections->arg)
    2394          12 :         dballowconnections = defGetBoolean(dallowconnections);
    2395          24 :     if (dconnlimit && dconnlimit->arg)
    2396             :     {
    2397           2 :         dbconnlimit = defGetInt32(dconnlimit);
    2398           2 :         if (dbconnlimit < DATCONNLIMIT_UNLIMITED)
    2399           0 :             ereport(ERROR,
    2400             :                     (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    2401             :                      errmsg("invalid connection limit: %d", dbconnlimit)));
    2402             :     }
    2403             : 
    2404             :     /*
    2405             :      * Get the old tuple.  We don't need a lock on the database per se,
    2406             :      * because we're not going to do anything that would mess up incoming
    2407             :      * connections.
    2408             :      */
    2409          24 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    2410          24 :     ScanKeyInit(&scankey,
    2411             :                 Anum_pg_database_datname,
    2412             :                 BTEqualStrategyNumber, F_NAMEEQ,
    2413          24 :                 CStringGetDatum(stmt->dbname));
    2414          24 :     scan = systable_beginscan(rel, DatabaseNameIndexId, true,
    2415             :                               NULL, 1, &scankey);
    2416          24 :     tuple = systable_getnext(scan);
    2417          24 :     if (!HeapTupleIsValid(tuple))
    2418           0 :         ereport(ERROR,
    2419             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2420             :                  errmsg("database \"%s\" does not exist", stmt->dbname)));
    2421             : 
    2422          24 :     datform = (Form_pg_database) GETSTRUCT(tuple);
    2423          24 :     dboid = datform->oid;
    2424             : 
    2425          24 :     if (database_is_invalid_form(datform))
    2426             :     {
    2427           2 :         ereport(FATAL,
    2428             :                 errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
    2429             :                 errmsg("cannot alter invalid database \"%s\"", stmt->dbname),
    2430             :                 errhint("Use DROP DATABASE to drop invalid databases."));
    2431             :     }
    2432             : 
    2433          22 :     if (!object_ownercheck(DatabaseRelationId, dboid, GetUserId()))
    2434           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2435           0 :                        stmt->dbname);
    2436             : 
    2437             :     /*
    2438             :      * In order to avoid getting locked out and having to go through
    2439             :      * standalone mode, we refuse to disallow connections to the database
    2440             :      * we're currently connected to.  Lockout can still happen with concurrent
    2441             :      * sessions but the likeliness of that is not high enough to worry about.
    2442             :      */
    2443          22 :     if (!dballowconnections && dboid == MyDatabaseId)
    2444           0 :         ereport(ERROR,
    2445             :                 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
    2446             :                  errmsg("cannot disallow connections for current database")));
    2447             : 
    2448             :     /*
    2449             :      * Build an updated tuple, perusing the information just obtained
    2450             :      */
    2451          22 :     if (distemplate)
    2452             :     {
    2453          10 :         new_record[Anum_pg_database_datistemplate - 1] = BoolGetDatum(dbistemplate);
    2454          10 :         new_record_repl[Anum_pg_database_datistemplate - 1] = true;
    2455             :     }
    2456          22 :     if (dallowconnections)
    2457             :     {
    2458          12 :         new_record[Anum_pg_database_datallowconn - 1] = BoolGetDatum(dballowconnections);
    2459          12 :         new_record_repl[Anum_pg_database_datallowconn - 1] = true;
    2460             :     }
    2461          22 :     if (dconnlimit)
    2462             :     {
    2463           0 :         new_record[Anum_pg_database_datconnlimit - 1] = Int32GetDatum(dbconnlimit);
    2464           0 :         new_record_repl[Anum_pg_database_datconnlimit - 1] = true;
    2465             :     }
    2466             : 
    2467          22 :     newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel), new_record,
    2468             :                                  new_record_nulls, new_record_repl);
    2469          22 :     CatalogTupleUpdate(rel, &tuple->t_self, newtuple);
    2470             : 
    2471          22 :     InvokeObjectPostAlterHook(DatabaseRelationId, dboid, 0);
    2472             : 
    2473          22 :     systable_endscan(scan);
    2474             : 
    2475             :     /* Close pg_database, but keep lock till commit */
    2476          22 :     table_close(rel, NoLock);
    2477             : 
    2478          22 :     return dboid;
    2479             : }
    2480             : 
    2481             : 
    2482             : /*
    2483             :  * ALTER DATABASE name REFRESH COLLATION VERSION
    2484             :  */
    2485             : ObjectAddress
    2486           6 : AlterDatabaseRefreshColl(AlterDatabaseRefreshCollStmt *stmt)
    2487             : {
    2488             :     Relation    rel;
    2489             :     ScanKeyData scankey;
    2490             :     SysScanDesc scan;
    2491             :     Oid         db_id;
    2492             :     HeapTuple   tuple;
    2493             :     Form_pg_database datForm;
    2494             :     ObjectAddress address;
    2495             :     Datum       datum;
    2496             :     bool        isnull;
    2497             :     char       *oldversion;
    2498             :     char       *newversion;
    2499             : 
    2500           6 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    2501           6 :     ScanKeyInit(&scankey,
    2502             :                 Anum_pg_database_datname,
    2503             :                 BTEqualStrategyNumber, F_NAMEEQ,
    2504           6 :                 CStringGetDatum(stmt->dbname));
    2505           6 :     scan = systable_beginscan(rel, DatabaseNameIndexId, true,
    2506             :                               NULL, 1, &scankey);
    2507           6 :     tuple = systable_getnext(scan);
    2508           6 :     if (!HeapTupleIsValid(tuple))
    2509           0 :         ereport(ERROR,
    2510             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2511             :                  errmsg("database \"%s\" does not exist", stmt->dbname)));
    2512             : 
    2513           6 :     datForm = (Form_pg_database) GETSTRUCT(tuple);
    2514           6 :     db_id = datForm->oid;
    2515             : 
    2516           6 :     if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    2517           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2518           0 :                        stmt->dbname);
    2519             : 
    2520           6 :     datum = heap_getattr(tuple, Anum_pg_database_datcollversion, RelationGetDescr(rel), &isnull);
    2521           6 :     oldversion = isnull ? NULL : TextDatumGetCString(datum);
    2522             : 
    2523           6 :     if (datForm->datlocprovider == COLLPROVIDER_LIBC)
    2524             :     {
    2525           4 :         datum = heap_getattr(tuple, Anum_pg_database_datcollate, RelationGetDescr(rel), &isnull);
    2526           4 :         if (isnull)
    2527           0 :             elog(ERROR, "unexpected null in pg_database");
    2528             :     }
    2529             :     else
    2530             :     {
    2531           2 :         datum = heap_getattr(tuple, Anum_pg_database_datlocale, RelationGetDescr(rel), &isnull);
    2532           2 :         if (isnull)
    2533           0 :             elog(ERROR, "unexpected null in pg_database");
    2534             :     }
    2535             : 
    2536           6 :     newversion = get_collation_actual_version(datForm->datlocprovider,
    2537           6 :                                               TextDatumGetCString(datum));
    2538             : 
    2539             :     /* cannot change from NULL to non-NULL or vice versa */
    2540           6 :     if ((!oldversion && newversion) || (oldversion && !newversion))
    2541           0 :         elog(ERROR, "invalid collation version change");
    2542           6 :     else if (oldversion && newversion && strcmp(newversion, oldversion) != 0)
    2543           0 :     {
    2544           0 :         bool        nulls[Natts_pg_database] = {0};
    2545           0 :         bool        replaces[Natts_pg_database] = {0};
    2546           0 :         Datum       values[Natts_pg_database] = {0};
    2547             : 
    2548           0 :         ereport(NOTICE,
    2549             :                 (errmsg("changing version from %s to %s",
    2550             :                         oldversion, newversion)));
    2551             : 
    2552           0 :         values[Anum_pg_database_datcollversion - 1] = CStringGetTextDatum(newversion);
    2553           0 :         replaces[Anum_pg_database_datcollversion - 1] = true;
    2554             : 
    2555           0 :         tuple = heap_modify_tuple(tuple, RelationGetDescr(rel),
    2556             :                                   values, nulls, replaces);
    2557           0 :         CatalogTupleUpdate(rel, &tuple->t_self, tuple);
    2558           0 :         heap_freetuple(tuple);
    2559             :     }
    2560             :     else
    2561           6 :         ereport(NOTICE,
    2562             :                 (errmsg("version has not changed")));
    2563             : 
    2564           6 :     InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    2565             : 
    2566           6 :     ObjectAddressSet(address, DatabaseRelationId, db_id);
    2567             : 
    2568           6 :     systable_endscan(scan);
    2569             : 
    2570           6 :     table_close(rel, NoLock);
    2571             : 
    2572           6 :     return address;
    2573             : }
    2574             : 
    2575             : 
    2576             : /*
    2577             :  * ALTER DATABASE name SET ...
    2578             :  */
    2579             : Oid
    2580        1058 : AlterDatabaseSet(AlterDatabaseSetStmt *stmt)
    2581             : {
    2582        1058 :     Oid         datid = get_database_oid(stmt->dbname, false);
    2583             : 
    2584             :     /*
    2585             :      * Obtain a lock on the database and make sure it didn't go away in the
    2586             :      * meantime.
    2587             :      */
    2588        1058 :     shdepLockAndCheckObject(DatabaseRelationId, datid);
    2589             : 
    2590        1058 :     if (!object_ownercheck(DatabaseRelationId, datid, GetUserId()))
    2591           0 :         aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2592           0 :                        stmt->dbname);
    2593             : 
    2594        1058 :     AlterSetting(datid, InvalidOid, stmt->setstmt);
    2595             : 
    2596        1058 :     UnlockSharedObject(DatabaseRelationId, datid, 0, AccessShareLock);
    2597             : 
    2598        1058 :     return datid;
    2599             : }
    2600             : 
    2601             : 
    2602             : /*
    2603             :  * ALTER DATABASE name OWNER TO newowner
    2604             :  */
    2605             : ObjectAddress
    2606          44 : AlterDatabaseOwner(const char *dbname, Oid newOwnerId)
    2607             : {
    2608             :     Oid         db_id;
    2609             :     HeapTuple   tuple;
    2610             :     Relation    rel;
    2611             :     ScanKeyData scankey;
    2612             :     SysScanDesc scan;
    2613             :     Form_pg_database datForm;
    2614             :     ObjectAddress address;
    2615             : 
    2616             :     /*
    2617             :      * Get the old tuple.  We don't need a lock on the database per se,
    2618             :      * because we're not going to do anything that would mess up incoming
    2619             :      * connections.
    2620             :      */
    2621          44 :     rel = table_open(DatabaseRelationId, RowExclusiveLock);
    2622          44 :     ScanKeyInit(&scankey,
    2623             :                 Anum_pg_database_datname,
    2624             :                 BTEqualStrategyNumber, F_NAMEEQ,
    2625             :                 CStringGetDatum(dbname));
    2626          44 :     scan = systable_beginscan(rel, DatabaseNameIndexId, true,
    2627             :                               NULL, 1, &scankey);
    2628          44 :     tuple = systable_getnext(scan);
    2629          44 :     if (!HeapTupleIsValid(tuple))
    2630           0 :         ereport(ERROR,
    2631             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    2632             :                  errmsg("database \"%s\" does not exist", dbname)));
    2633             : 
    2634          44 :     datForm = (Form_pg_database) GETSTRUCT(tuple);
    2635          44 :     db_id = datForm->oid;
    2636             : 
    2637             :     /*
    2638             :      * If the new owner is the same as the existing owner, consider the
    2639             :      * command to have succeeded.  This is to be consistent with other
    2640             :      * objects.
    2641             :      */
    2642          44 :     if (datForm->datdba != newOwnerId)
    2643             :     {
    2644             :         Datum       repl_val[Natts_pg_database];
    2645          24 :         bool        repl_null[Natts_pg_database] = {0};
    2646          24 :         bool        repl_repl[Natts_pg_database] = {0};
    2647             :         Acl        *newAcl;
    2648             :         Datum       aclDatum;
    2649             :         bool        isNull;
    2650             :         HeapTuple   newtuple;
    2651             : 
    2652             :         /* Otherwise, must be owner of the existing object */
    2653          24 :         if (!object_ownercheck(DatabaseRelationId, db_id, GetUserId()))
    2654           0 :             aclcheck_error(ACLCHECK_NOT_OWNER, OBJECT_DATABASE,
    2655             :                            dbname);
    2656             : 
    2657             :         /* Must be able to become new owner */
    2658          24 :         check_can_set_role(GetUserId(), newOwnerId);
    2659             : 
    2660             :         /*
    2661             :          * must have createdb rights
    2662             :          *
    2663             :          * NOTE: This is different from other alter-owner checks in that the
    2664             :          * current user is checked for createdb privileges instead of the
    2665             :          * destination owner.  This is consistent with the CREATE case for
    2666             :          * databases.  Because superusers will always have this right, we need
    2667             :          * no special case for them.
    2668             :          */
    2669          24 :         if (!have_createdb_privilege())
    2670           0 :             ereport(ERROR,
    2671             :                     (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
    2672             :                      errmsg("permission denied to change owner of database")));
    2673             : 
    2674          24 :         repl_repl[Anum_pg_database_datdba - 1] = true;
    2675          24 :         repl_val[Anum_pg_database_datdba - 1] = ObjectIdGetDatum(newOwnerId);
    2676             : 
    2677             :         /*
    2678             :          * Determine the modified ACL for the new owner.  This is only
    2679             :          * necessary when the ACL is non-null.
    2680             :          */
    2681          24 :         aclDatum = heap_getattr(tuple,
    2682             :                                 Anum_pg_database_datacl,
    2683             :                                 RelationGetDescr(rel),
    2684             :                                 &isNull);
    2685          24 :         if (!isNull)
    2686             :         {
    2687           0 :             newAcl = aclnewowner(DatumGetAclP(aclDatum),
    2688             :                                  datForm->datdba, newOwnerId);
    2689           0 :             repl_repl[Anum_pg_database_datacl - 1] = true;
    2690           0 :             repl_val[Anum_pg_database_datacl - 1] = PointerGetDatum(newAcl);
    2691             :         }
    2692             : 
    2693          24 :         newtuple = heap_modify_tuple(tuple, RelationGetDescr(rel), repl_val, repl_null, repl_repl);
    2694          24 :         CatalogTupleUpdate(rel, &newtuple->t_self, newtuple);
    2695             : 
    2696          24 :         heap_freetuple(newtuple);
    2697             : 
    2698             :         /* Update owner dependency reference */
    2699          24 :         changeDependencyOnOwner(DatabaseRelationId, db_id, newOwnerId);
    2700             :     }
    2701             : 
    2702          44 :     InvokeObjectPostAlterHook(DatabaseRelationId, db_id, 0);
    2703             : 
    2704          44 :     ObjectAddressSet(address, DatabaseRelationId, db_id);
    2705             : 
    2706          44 :     systable_endscan(scan);
    2707             : 
    2708             :     /* Close pg_database, but keep lock till commit */
    2709          44 :     table_close(rel, NoLock);
    2710             : 
    2711          44 :     return address;
    2712             : }
    2713             : 
    2714             : 
    2715             : Datum
    2716          76 : pg_database_collation_actual_version(PG_FUNCTION_ARGS)
    2717             : {
    2718          76 :     Oid         dbid = PG_GETARG_OID(0);
    2719             :     HeapTuple   tp;
    2720             :     char        datlocprovider;
    2721             :     Datum       datum;
    2722             :     char       *version;
    2723             : 
    2724          76 :     tp = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dbid));
    2725          76 :     if (!HeapTupleIsValid(tp))
    2726           0 :         ereport(ERROR,
    2727             :                 (errcode(ERRCODE_UNDEFINED_OBJECT),
    2728             :                  errmsg("database with OID %u does not exist", dbid)));
    2729             : 
    2730          76 :     datlocprovider = ((Form_pg_database) GETSTRUCT(tp))->datlocprovider;
    2731             : 
    2732          76 :     if (datlocprovider == COLLPROVIDER_LIBC)
    2733          62 :         datum = SysCacheGetAttrNotNull(DATABASEOID, tp, Anum_pg_database_datcollate);
    2734             :     else
    2735          14 :         datum = SysCacheGetAttrNotNull(DATABASEOID, tp, Anum_pg_database_datlocale);
    2736             : 
    2737          76 :     version = get_collation_actual_version(datlocprovider,
    2738          76 :                                            TextDatumGetCString(datum));
    2739             : 
    2740          76 :     ReleaseSysCache(tp);
    2741             : 
    2742          76 :     if (version)
    2743          48 :         PG_RETURN_TEXT_P(cstring_to_text(version));
    2744             :     else
    2745          28 :         PG_RETURN_NULL();
    2746             : }
    2747             : 
    2748             : 
    2749             : /*
    2750             :  * Helper functions
    2751             :  */
    2752             : 
    2753             : /*
    2754             :  * Look up info about the database named "name".  If the database exists,
    2755             :  * obtain the specified lock type on it, fill in any of the remaining
    2756             :  * parameters that aren't NULL, and return true.  If no such database,
    2757             :  * return false.
    2758             :  */
    2759             : static bool
    2760         732 : get_db_info(const char *name, LOCKMODE lockmode,
    2761             :             Oid *dbIdP, Oid *ownerIdP,
    2762             :             int *encodingP, bool *dbIsTemplateP, bool *dbAllowConnP, bool *dbHasLoginEvtP,
    2763             :             TransactionId *dbFrozenXidP, MultiXactId *dbMinMultiP,
    2764             :             Oid *dbTablespace, char **dbCollate, char **dbCtype, char **dbLocale,
    2765             :             char **dbIcurules,
    2766             :             char *dbLocProvider,
    2767             :             char **dbCollversion)
    2768             : {
    2769         732 :     bool        result = false;
    2770             :     Relation    relation;
    2771             : 
    2772             :     Assert(name);
    2773             : 
    2774             :     /* Caller may wish to grab a better lock on pg_database beforehand... */
    2775         732 :     relation = table_open(DatabaseRelationId, AccessShareLock);
    2776             : 
    2777             :     /*
    2778             :      * Loop covers the rare case where the database is renamed before we can
    2779             :      * lock it.  We try again just in case we can find a new one of the same
    2780             :      * name.
    2781             :      */
    2782             :     for (;;)
    2783           0 :     {
    2784             :         ScanKeyData scanKey;
    2785             :         SysScanDesc scan;
    2786             :         HeapTuple   tuple;
    2787             :         Oid         dbOid;
    2788             : 
    2789             :         /*
    2790             :          * there's no syscache for database-indexed-by-name, so must do it the
    2791             :          * hard way
    2792             :          */
    2793         732 :         ScanKeyInit(&scanKey,
    2794             :                     Anum_pg_database_datname,
    2795             :                     BTEqualStrategyNumber, F_NAMEEQ,
    2796             :                     CStringGetDatum(name));
    2797             : 
    2798         732 :         scan = systable_beginscan(relation, DatabaseNameIndexId, true,
    2799             :                                   NULL, 1, &scanKey);
    2800             : 
    2801         732 :         tuple = systable_getnext(scan);
    2802             : 
    2803         732 :         if (!HeapTupleIsValid(tuple))
    2804             :         {
    2805             :             /* definitely no database of that name */
    2806          32 :             systable_endscan(scan);
    2807          32 :             break;
    2808             :         }
    2809             : 
    2810         700 :         dbOid = ((Form_pg_database) GETSTRUCT(tuple))->oid;
    2811             : 
    2812         700 :         systable_endscan(scan);
    2813             : 
    2814             :         /*
    2815             :          * Now that we have a database OID, we can try to lock the DB.
    2816             :          */
    2817         700 :         if (lockmode != NoLock)
    2818         700 :             LockSharedObject(DatabaseRelationId, dbOid, 0, lockmode);
    2819             : 
    2820             :         /*
    2821             :          * And now, re-fetch the tuple by OID.  If it's still there and still
    2822             :          * the same name, we win; else, drop the lock and loop back to try
    2823             :          * again.
    2824             :          */
    2825         700 :         tuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dbOid));
    2826         700 :         if (HeapTupleIsValid(tuple))
    2827             :         {
    2828         700 :             Form_pg_database dbform = (Form_pg_database) GETSTRUCT(tuple);
    2829             : 
    2830         700 :             if (strcmp(name, NameStr(dbform->datname)) == 0)
    2831             :             {
    2832             :                 Datum       datum;
    2833             :                 bool        isnull;
    2834             : 
    2835             :                 /* oid of the database */
    2836         700 :                 if (dbIdP)
    2837         700 :                     *dbIdP = dbOid;
    2838             :                 /* oid of the owner */
    2839         700 :                 if (ownerIdP)
    2840         628 :                     *ownerIdP = dbform->datdba;
    2841             :                 /* character encoding */
    2842         700 :                 if (encodingP)
    2843         628 :                     *encodingP = dbform->encoding;
    2844             :                 /* allowed as template? */
    2845         700 :                 if (dbIsTemplateP)
    2846         690 :                     *dbIsTemplateP = dbform->datistemplate;
    2847             :                 /* Has on login event trigger? */
    2848         700 :                 if (dbHasLoginEvtP)
    2849         628 :                     *dbHasLoginEvtP = dbform->dathasloginevt;
    2850             :                 /* allowing connections? */
    2851         700 :                 if (dbAllowConnP)
    2852         628 :                     *dbAllowConnP = dbform->datallowconn;
    2853             :                 /* limit of frozen XIDs */
    2854         700 :                 if (dbFrozenXidP)
    2855         628 :                     *dbFrozenXidP = dbform->datfrozenxid;
    2856             :                 /* minimum MultiXactId */
    2857         700 :                 if (dbMinMultiP)
    2858         628 :                     *dbMinMultiP = dbform->datminmxid;
    2859             :                 /* default tablespace for this database */
    2860         700 :                 if (dbTablespace)
    2861         638 :                     *dbTablespace = dbform->dattablespace;
    2862             :                 /* default locale settings for this database */
    2863         700 :                 if (dbLocProvider)
    2864         628 :                     *dbLocProvider = dbform->datlocprovider;
    2865         700 :                 if (dbCollate)
    2866             :                 {
    2867         628 :                     datum = SysCacheGetAttrNotNull(DATABASEOID, tuple, Anum_pg_database_datcollate);
    2868         628 :                     *dbCollate = TextDatumGetCString(datum);
    2869             :                 }
    2870         700 :                 if (dbCtype)
    2871             :                 {
    2872         628 :                     datum = SysCacheGetAttrNotNull(DATABASEOID, tuple, Anum_pg_database_datctype);
    2873         628 :                     *dbCtype = TextDatumGetCString(datum);
    2874             :                 }
    2875         700 :                 if (dbLocale)
    2876             :                 {
    2877         628 :                     datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datlocale, &isnull);
    2878         628 :                     if (isnull)
    2879         572 :                         *dbLocale = NULL;
    2880             :                     else
    2881          56 :                         *dbLocale = TextDatumGetCString(datum);
    2882             :                 }
    2883         700 :                 if (dbIcurules)
    2884             :                 {
    2885         628 :                     datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_daticurules, &isnull);
    2886         628 :                     if (isnull)
    2887         628 :                         *dbIcurules = NULL;
    2888             :                     else
    2889           0 :                         *dbIcurules = TextDatumGetCString(datum);
    2890             :                 }
    2891         700 :                 if (dbCollversion)
    2892             :                 {
    2893         628 :                     datum = SysCacheGetAttr(DATABASEOID, tuple, Anum_pg_database_datcollversion, &isnull);
    2894         628 :                     if (isnull)
    2895         386 :                         *dbCollversion = NULL;
    2896             :                     else
    2897         242 :                         *dbCollversion = TextDatumGetCString(datum);
    2898             :                 }
    2899         700 :                 ReleaseSysCache(tuple);
    2900         700 :                 result = true;
    2901         700 :                 break;
    2902             :             }
    2903             :             /* can only get here if it was just renamed */
    2904           0 :             ReleaseSysCache(tuple);
    2905             :         }
    2906             : 
    2907           0 :         if (lockmode != NoLock)
    2908           0 :             UnlockSharedObject(DatabaseRelationId, dbOid, 0, lockmode);
    2909             :     }
    2910             : 
    2911         732 :     table_close(relation, AccessShareLock);
    2912             : 
    2913         732 :     return result;
    2914             : }
    2915             : 
    2916             : /* Check if current user has createdb privileges */
    2917             : bool
    2918         688 : have_createdb_privilege(void)
    2919             : {
    2920         688 :     bool        result = false;
    2921             :     HeapTuple   utup;
    2922             : 
    2923             :     /* Superusers can always do everything */
    2924         688 :     if (superuser())
    2925         652 :         return true;
    2926             : 
    2927          36 :     utup = SearchSysCache1(AUTHOID, ObjectIdGetDatum(GetUserId()));
    2928          36 :     if (HeapTupleIsValid(utup))
    2929             :     {
    2930          36 :         result = ((Form_pg_authid) GETSTRUCT(utup))->rolcreatedb;
    2931          36 :         ReleaseSysCache(utup);
    2932             :     }
    2933          36 :     return result;
    2934             : }
    2935             : 
    2936             : /*
    2937             :  * Remove tablespace directories
    2938             :  *
    2939             :  * We don't know what tablespaces db_id is using, so iterate through all
    2940             :  * tablespaces removing <tablespace>/db_id
    2941             :  */
    2942             : static void
    2943          60 : remove_dbtablespaces(Oid db_id)
    2944             : {
    2945             :     Relation    rel;
    2946             :     TableScanDesc scan;
    2947             :     HeapTuple   tuple;
    2948          60 :     List       *ltblspc = NIL;
    2949             :     ListCell   *cell;
    2950             :     int         ntblspc;
    2951             :     int         i;
    2952             :     Oid        *tablespace_ids;
    2953             : 
    2954          60 :     rel = table_open(TableSpaceRelationId, AccessShareLock);
    2955          60 :     scan = table_beginscan_catalog(rel, 0, NULL);
    2956         222 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    2957             :     {
    2958         162 :         Form_pg_tablespace spcform = (Form_pg_tablespace) GETSTRUCT(tuple);
    2959         162 :         Oid         dsttablespace = spcform->oid;
    2960             :         char       *dstpath;
    2961             :         struct stat st;
    2962             : 
    2963             :         /* Don't mess with the global tablespace */
    2964         162 :         if (dsttablespace == GLOBALTABLESPACE_OID)
    2965         102 :             continue;
    2966             : 
    2967         102 :         dstpath = GetDatabasePath(db_id, dsttablespace);
    2968             : 
    2969         102 :         if (lstat(dstpath, &st) < 0 || !S_ISDIR(st.st_mode))
    2970             :         {
    2971             :             /* Assume we can ignore it */
    2972          42 :             pfree(dstpath);
    2973          42 :             continue;
    2974             :         }
    2975             : 
    2976          60 :         if (!rmtree(dstpath, true))
    2977           0 :             ereport(WARNING,
    2978             :                     (errmsg("some useless files may be left behind in old database directory \"%s\"",
    2979             :                             dstpath)));
    2980             : 
    2981          60 :         ltblspc = lappend_oid(ltblspc, dsttablespace);
    2982          60 :         pfree(dstpath);
    2983             :     }
    2984             : 
    2985          60 :     ntblspc = list_length(ltblspc);
    2986          60 :     if (ntblspc == 0)
    2987             :     {
    2988           0 :         table_endscan(scan);
    2989           0 :         table_close(rel, AccessShareLock);
    2990           0 :         return;
    2991             :     }
    2992             : 
    2993          60 :     tablespace_ids = (Oid *) palloc(ntblspc * sizeof(Oid));
    2994          60 :     i = 0;
    2995         120 :     foreach(cell, ltblspc)
    2996          60 :         tablespace_ids[i++] = lfirst_oid(cell);
    2997             : 
    2998             :     /* Record the filesystem change in XLOG */
    2999             :     {
    3000             :         xl_dbase_drop_rec xlrec;
    3001             : 
    3002          60 :         xlrec.db_id = db_id;
    3003          60 :         xlrec.ntablespaces = ntblspc;
    3004             : 
    3005          60 :         XLogBeginInsert();
    3006          60 :         XLogRegisterData((char *) &xlrec, MinSizeOfDbaseDropRec);
    3007          60 :         XLogRegisterData((char *) tablespace_ids, ntblspc * sizeof(Oid));
    3008             : 
    3009          60 :         (void) XLogInsert(RM_DBASE_ID,
    3010             :                           XLOG_DBASE_DROP | XLR_SPECIAL_REL_UPDATE);
    3011             :     }
    3012             : 
    3013          60 :     list_free(ltblspc);
    3014          60 :     pfree(tablespace_ids);
    3015             : 
    3016          60 :     table_endscan(scan);
    3017          60 :     table_close(rel, AccessShareLock);
    3018             : }
    3019             : 
    3020             : /*
    3021             :  * Check for existing files that conflict with a proposed new DB OID;
    3022             :  * return true if there are any
    3023             :  *
    3024             :  * If there were a subdirectory in any tablespace matching the proposed new
    3025             :  * OID, we'd get a create failure due to the duplicate name ... and then we'd
    3026             :  * try to remove that already-existing subdirectory during the cleanup in
    3027             :  * remove_dbtablespaces.  Nuking existing files seems like a bad idea, so
    3028             :  * instead we make this extra check before settling on the OID of the new
    3029             :  * database.  This exactly parallels what GetNewRelFileNumber() does for table
    3030             :  * relfilenumber values.
    3031             :  */
    3032             : static bool
    3033         602 : check_db_file_conflict(Oid db_id)
    3034             : {
    3035         602 :     bool        result = false;
    3036             :     Relation    rel;
    3037             :     TableScanDesc scan;
    3038             :     HeapTuple   tuple;
    3039             : 
    3040         602 :     rel = table_open(TableSpaceRelationId, AccessShareLock);
    3041         602 :     scan = table_beginscan_catalog(rel, 0, NULL);
    3042        1896 :     while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
    3043             :     {
    3044        1294 :         Form_pg_tablespace spcform = (Form_pg_tablespace) GETSTRUCT(tuple);
    3045        1294 :         Oid         dsttablespace = spcform->oid;
    3046             :         char       *dstpath;
    3047             :         struct stat st;
    3048             : 
    3049             :         /* Don't mess with the global tablespace */
    3050        1294 :         if (dsttablespace == GLOBALTABLESPACE_OID)
    3051         602 :             continue;
    3052             : 
    3053         692 :         dstpath = GetDatabasePath(db_id, dsttablespace);
    3054             : 
    3055         692 :         if (lstat(dstpath, &st) == 0)
    3056             :         {
    3057             :             /* Found a conflicting file (or directory, whatever) */
    3058           0 :             pfree(dstpath);
    3059           0 :             result = true;
    3060           0 :             break;
    3061             :         }
    3062             : 
    3063         692 :         pfree(dstpath);
    3064             :     }
    3065             : 
    3066         602 :     table_endscan(scan);
    3067         602 :     table_close(rel, AccessShareLock);
    3068             : 
    3069         602 :     return result;
    3070             : }
    3071             : 
    3072             : /*
    3073             :  * Issue a suitable errdetail message for a busy database
    3074             :  */
    3075             : static int
    3076           0 : errdetail_busy_db(int notherbackends, int npreparedxacts)
    3077             : {
    3078           0 :     if (notherbackends > 0 && npreparedxacts > 0)
    3079             : 
    3080             :         /*
    3081             :          * We don't deal with singular versus plural here, since gettext
    3082             :          * doesn't support multiple plurals in one string.
    3083             :          */
    3084           0 :         errdetail("There are %d other session(s) and %d prepared transaction(s) using the database.",
    3085             :                   notherbackends, npreparedxacts);
    3086           0 :     else if (notherbackends > 0)
    3087           0 :         errdetail_plural("There is %d other session using the database.",
    3088             :                          "There are %d other sessions using the database.",
    3089             :                          notherbackends,
    3090             :                          notherbackends);
    3091             :     else
    3092           0 :         errdetail_plural("There is %d prepared transaction using the database.",
    3093             :                          "There are %d prepared transactions using the database.",
    3094             :                          npreparedxacts,
    3095             :                          npreparedxacts);
    3096           0 :     return 0;                   /* just to keep ereport macro happy */
    3097             : }
    3098             : 
    3099             : /*
    3100             :  * get_database_oid - given a database name, look up the OID
    3101             :  *
    3102             :  * If missing_ok is false, throw an error if database name not found.  If
    3103             :  * true, just return InvalidOid.
    3104             :  */
    3105             : Oid
    3106        2352 : get_database_oid(const char *dbname, bool missing_ok)
    3107             : {
    3108             :     Relation    pg_database;
    3109             :     ScanKeyData entry[1];
    3110             :     SysScanDesc scan;
    3111             :     HeapTuple   dbtuple;
    3112             :     Oid         oid;
    3113             : 
    3114             :     /*
    3115             :      * There's no syscache for pg_database indexed by name, so we must look
    3116             :      * the hard way.
    3117             :      */
    3118        2352 :     pg_database = table_open(DatabaseRelationId, AccessShareLock);
    3119        2352 :     ScanKeyInit(&entry[0],
    3120             :                 Anum_pg_database_datname,
    3121             :                 BTEqualStrategyNumber, F_NAMEEQ,
    3122             :                 CStringGetDatum(dbname));
    3123        2352 :     scan = systable_beginscan(pg_database, DatabaseNameIndexId, true,
    3124             :                               NULL, 1, entry);
    3125             : 
    3126        2352 :     dbtuple = systable_getnext(scan);
    3127             : 
    3128             :     /* We assume that there can be at most one matching tuple */
    3129        2352 :     if (HeapTupleIsValid(dbtuple))
    3130        1744 :         oid = ((Form_pg_database) GETSTRUCT(dbtuple))->oid;
    3131             :     else
    3132         608 :         oid = InvalidOid;
    3133             : 
    3134        2352 :     systable_endscan(scan);
    3135        2352 :     table_close(pg_database, AccessShareLock);
    3136             : 
    3137        2352 :     if (!OidIsValid(oid) && !missing_ok)
    3138           6 :         ereport(ERROR,
    3139             :                 (errcode(ERRCODE_UNDEFINED_DATABASE),
    3140             :                  errmsg("database \"%s\" does not exist",
    3141             :                         dbname)));
    3142             : 
    3143        2346 :     return oid;
    3144             : }
    3145             : 
    3146             : 
    3147             : /*
    3148             :  * get_database_name - given a database OID, look up the name
    3149             :  *
    3150             :  * Returns a palloc'd string, or NULL if no such database.
    3151             :  */
    3152             : char *
    3153       26646 : get_database_name(Oid dbid)
    3154             : {
    3155             :     HeapTuple   dbtuple;
    3156             :     char       *result;
    3157             : 
    3158       26646 :     dbtuple = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dbid));
    3159       26646 :     if (HeapTupleIsValid(dbtuple))
    3160             :     {
    3161       26446 :         result = pstrdup(NameStr(((Form_pg_database) GETSTRUCT(dbtuple))->datname));
    3162       26446 :         ReleaseSysCache(dbtuple);
    3163             :     }
    3164             :     else
    3165         200 :         result = NULL;
    3166             : 
    3167       26646 :     return result;
    3168             : }
    3169             : 
    3170             : 
    3171             : /*
    3172             :  * While dropping a database the pg_database row is marked invalid, but the
    3173             :  * catalog contents still exist. Connections to such a database are not
    3174             :  * allowed.
    3175             :  */
    3176             : bool
    3177       26862 : database_is_invalid_form(Form_pg_database datform)
    3178             : {
    3179       26862 :     return datform->datconnlimit == DATCONNLIMIT_INVALID_DB;
    3180             : }
    3181             : 
    3182             : 
    3183             : /*
    3184             :  * Convenience wrapper around database_is_invalid_form()
    3185             :  */
    3186             : bool
    3187         628 : database_is_invalid_oid(Oid dboid)
    3188             : {
    3189             :     HeapTuple   dbtup;
    3190             :     Form_pg_database dbform;
    3191             :     bool        invalid;
    3192             : 
    3193         628 :     dbtup = SearchSysCache1(DATABASEOID, ObjectIdGetDatum(dboid));
    3194         628 :     if (!HeapTupleIsValid(dbtup))
    3195           0 :         elog(ERROR, "cache lookup failed for database %u", dboid);
    3196         628 :     dbform = (Form_pg_database) GETSTRUCT(dbtup);
    3197             : 
    3198         628 :     invalid = database_is_invalid_form(dbform);
    3199             : 
    3200         628 :     ReleaseSysCache(dbtup);
    3201             : 
    3202         628 :     return invalid;
    3203             : }
    3204             : 
    3205             : 
    3206             : /*
    3207             :  * recovery_create_dbdir()
    3208             :  *
    3209             :  * During recovery, there's a case where we validly need to recover a missing
    3210             :  * tablespace directory so that recovery can continue.  This happens when
    3211             :  * recovery wants to create a database but the holding tablespace has been
    3212             :  * removed before the server stopped.  Since we expect that the directory will
    3213             :  * be gone before reaching recovery consistency, and we have no knowledge about
    3214             :  * the tablespace other than its OID here, we create a real directory under
    3215             :  * pg_tblspc here instead of restoring the symlink.
    3216             :  *
    3217             :  * If only_tblspc is true, then the requested directory must be in pg_tblspc/
    3218             :  */
    3219             : static void
    3220          40 : recovery_create_dbdir(char *path, bool only_tblspc)
    3221             : {
    3222             :     struct stat st;
    3223             : 
    3224             :     Assert(RecoveryInProgress());
    3225             : 
    3226          40 :     if (stat(path, &st) == 0)
    3227          40 :         return;
    3228             : 
    3229           0 :     if (only_tblspc && strstr(path, "pg_tblspc/") == NULL)
    3230           0 :         elog(PANIC, "requested to created invalid directory: %s", path);
    3231             : 
    3232           0 :     if (reachedConsistency && !allow_in_place_tablespaces)
    3233           0 :         ereport(PANIC,
    3234             :                 errmsg("missing directory \"%s\"", path));
    3235             : 
    3236           0 :     elog(reachedConsistency ? WARNING : DEBUG1,
    3237             :          "creating missing directory: %s", path);
    3238             : 
    3239           0 :     if (pg_mkdir_p(path, pg_dir_create_mode) != 0)
    3240           0 :         ereport(PANIC,
    3241             :                 errmsg("could not create missing directory \"%s\": %m", path));
    3242             : }
    3243             : 
    3244             : 
    3245             : /*
    3246             :  * DATABASE resource manager's routines
    3247             :  */
    3248             : void
    3249          68 : dbase_redo(XLogReaderState *record)
    3250             : {
    3251          68 :     uint8       info = XLogRecGetInfo(record) & ~XLR_INFO_MASK;
    3252             : 
    3253             :     /* Backup blocks are not used in dbase records */
    3254             :     Assert(!XLogRecHasAnyBlockRefs(record));
    3255             : 
    3256          68 :     if (info == XLOG_DBASE_CREATE_FILE_COPY)
    3257             :     {
    3258           6 :         xl_dbase_create_file_copy_rec *xlrec =
    3259           6 :             (xl_dbase_create_file_copy_rec *) XLogRecGetData(record);
    3260             :         char       *src_path;
    3261             :         char       *dst_path;
    3262             :         char       *parent_path;
    3263             :         struct stat st;
    3264             : 
    3265           6 :         src_path = GetDatabasePath(xlrec->src_db_id, xlrec->src_tablespace_id);
    3266           6 :         dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
    3267             : 
    3268             :         /*
    3269             :          * Our theory for replaying a CREATE is to forcibly drop the target
    3270             :          * subdirectory if present, then re-copy the source data. This may be
    3271             :          * more work than needed, but it is simple to implement.
    3272             :          */
    3273           6 :         if (stat(dst_path, &st) == 0 && S_ISDIR(st.st_mode))
    3274             :         {
    3275           0 :             if (!rmtree(dst_path, true))
    3276             :                 /* If this failed, copydir() below is going to error. */
    3277           0 :                 ereport(WARNING,
    3278             :                         (errmsg("some useless files may be left behind in old database directory \"%s\"",
    3279             :                                 dst_path)));
    3280             :         }
    3281             : 
    3282             :         /*
    3283             :          * If the parent of the target path doesn't exist, create it now. This
    3284             :          * enables us to create the target underneath later.
    3285             :          */
    3286           6 :         parent_path = pstrdup(dst_path);
    3287           6 :         get_parent_directory(parent_path);
    3288           6 :         if (stat(parent_path, &st) < 0)
    3289             :         {
    3290           0 :             if (errno != ENOENT)
    3291           0 :                 ereport(FATAL,
    3292             :                         errmsg("could not stat directory \"%s\": %m",
    3293             :                                dst_path));
    3294             : 
    3295             :             /* create the parent directory if needed and valid */
    3296           0 :             recovery_create_dbdir(parent_path, true);
    3297             :         }
    3298           6 :         pfree(parent_path);
    3299             : 
    3300             :         /*
    3301             :          * There's a case where the copy source directory is missing for the
    3302             :          * same reason above.  Create the empty source directory so that
    3303             :          * copydir below doesn't fail.  The directory will be dropped soon by
    3304             :          * recovery.
    3305             :          */
    3306           6 :         if (stat(src_path, &st) < 0 && errno == ENOENT)
    3307           0 :             recovery_create_dbdir(src_path, false);
    3308             : 
    3309             :         /*
    3310             :          * Force dirty buffers out to disk, to ensure source database is
    3311             :          * up-to-date for the copy.
    3312             :          */
    3313           6 :         FlushDatabaseBuffers(xlrec->src_db_id);
    3314             : 
    3315             :         /* Close all sgmr fds in all backends. */
    3316           6 :         WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    3317             : 
    3318             :         /*
    3319             :          * Copy this subdirectory to the new location
    3320             :          *
    3321             :          * We don't need to copy subdirectories
    3322             :          */
    3323           6 :         copydir(src_path, dst_path, false);
    3324             : 
    3325           6 :         pfree(src_path);
    3326           6 :         pfree(dst_path);
    3327             :     }
    3328          62 :     else if (info == XLOG_DBASE_CREATE_WAL_LOG)
    3329             :     {
    3330          40 :         xl_dbase_create_wal_log_rec *xlrec =
    3331          40 :             (xl_dbase_create_wal_log_rec *) XLogRecGetData(record);
    3332             :         char       *dbpath;
    3333             :         char       *parent_path;
    3334             : 
    3335          40 :         dbpath = GetDatabasePath(xlrec->db_id, xlrec->tablespace_id);
    3336             : 
    3337             :         /* create the parent directory if needed and valid */
    3338          40 :         parent_path = pstrdup(dbpath);
    3339          40 :         get_parent_directory(parent_path);
    3340          40 :         recovery_create_dbdir(parent_path, true);
    3341             : 
    3342             :         /* Create the database directory with the version file. */
    3343          40 :         CreateDirAndVersionFile(dbpath, xlrec->db_id, xlrec->tablespace_id,
    3344             :                                 true);
    3345          40 :         pfree(dbpath);
    3346             :     }
    3347          22 :     else if (info == XLOG_DBASE_DROP)
    3348             :     {
    3349          22 :         xl_dbase_drop_rec *xlrec = (xl_dbase_drop_rec *) XLogRecGetData(record);
    3350             :         char       *dst_path;
    3351             :         int         i;
    3352             : 
    3353          22 :         if (InHotStandby)
    3354             :         {
    3355             :             /*
    3356             :              * Lock database while we resolve conflicts to ensure that
    3357             :              * InitPostgres() cannot fully re-execute concurrently. This
    3358             :              * avoids backends re-connecting automatically to same database,
    3359             :              * which can happen in some cases.
    3360             :              *
    3361             :              * This will lock out walsenders trying to connect to db-specific
    3362             :              * slots for logical decoding too, so it's safe for us to drop
    3363             :              * slots.
    3364             :              */
    3365          22 :             LockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
    3366          22 :             ResolveRecoveryConflictWithDatabase(xlrec->db_id);
    3367             :         }
    3368             : 
    3369             :         /* Drop any database-specific replication slots */
    3370          22 :         ReplicationSlotsDropDBSlots(xlrec->db_id);
    3371             : 
    3372             :         /* Drop pages for this database that are in the shared buffer cache */
    3373          22 :         DropDatabaseBuffers(xlrec->db_id);
    3374             : 
    3375             :         /* Also, clean out any fsync requests that might be pending in md.c */
    3376          22 :         ForgetDatabaseSyncRequests(xlrec->db_id);
    3377             : 
    3378             :         /* Clean out the xlog relcache too */
    3379          22 :         XLogDropDatabase(xlrec->db_id);
    3380             : 
    3381             :         /* Close all sgmr fds in all backends. */
    3382          22 :         WaitForProcSignalBarrier(EmitProcSignalBarrier(PROCSIGNAL_BARRIER_SMGRRELEASE));
    3383             : 
    3384          44 :         for (i = 0; i < xlrec->ntablespaces; i++)
    3385             :         {
    3386          22 :             dst_path = GetDatabasePath(xlrec->db_id, xlrec->tablespace_ids[i]);
    3387             : 
    3388             :             /* And remove the physical files */
    3389          22 :             if (!rmtree(dst_path, true))
    3390           0 :                 ereport(WARNING,
    3391             :                         (errmsg("some useless files may be left behind in old database directory \"%s\"",
    3392             :                                 dst_path)));
    3393          22 :             pfree(dst_path);
    3394             :         }
    3395             : 
    3396          22 :         if (InHotStandby)
    3397             :         {
    3398             :             /*
    3399             :              * Release locks prior to commit. XXX There is a race condition
    3400             :              * here that may allow backends to reconnect, but the window for
    3401             :              * this is small because the gap between here and commit is mostly
    3402             :              * fairly small and it is unlikely that people will be dropping
    3403             :              * databases that we are trying to connect to anyway.
    3404             :              */
    3405          22 :             UnlockSharedObjectForSession(DatabaseRelationId, xlrec->db_id, 0, AccessExclusiveLock);
    3406             :         }
    3407             :     }
    3408             :     else
    3409           0 :         elog(PANIC, "dbase_redo: unknown op code %u", info);
    3410          68 : }

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