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Code Activity

Mega-commit to make heap_open/heap_openr/heap_close take an

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additional argument specifying the kind of lock to acquire/release (or
'NoLock' to do no lock processing).  Ensure that all relations are locked
with some appropriate lock level before being examined --- this ensures
that relevant shared-inval messages have been processed and should prevent
problems caused by concurrent VACUUM.  Fix several bugs having to do with
mismatched increment/decrement of relation ref count and mismatched
heap_open/close (which amounts to the same thing).  A bogus ref count on
a relation doesn't matter much *unless* a SI Inval message happens to
arrive at the wrong time, which is probably why we got away with this
sloppiness for so long.  Repair missing grab of AccessExclusiveLock in
DROP TABLE, ALTER/RENAME TABLE, etc, as noted by Hiroshi.
Recommend 'make clean all' after pulling this update; I modified the
Relation struct layout slightly.
Will post further discussion to pghackers list shortly.
This commit is contained in:
Tom Lane
1999-09-18 19:08:25 +00:00
parent 6c86fd5ba4
commit bd272cace6
70 changed files with 1094 additions and 1215 deletions
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48
src/backend/commands/rename.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/rename.c,v 1.32 1999/07/17 20:16:53 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/rename.c,v 1.33 1999/09/18 19:06:40 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -48,6 +48,7 @@ renameatt(char *relname,
char *userName,
int recurse)
{
Relation targetrelation;
Relation attrelation;
HeapTuple reltup,
oldatttup,
@ -71,6 +72,14 @@ renameatt(char *relname,
relname);
#endif
/*
* Grab an exclusive lock on the target table, which we will NOT release
* until end of transaction.
*/
targetrelation = heap_openr(relname, AccessExclusiveLock);
relid = RelationGetRelid(targetrelation);
heap_close(targetrelation, NoLock); /* close rel but keep lock! */
/*
* if the 'recurse' flag is set then we are supposed to rename this
* attribute in all classes that inherit from 'relname' (as well as in
@ -82,16 +91,11 @@ renameatt(char *relname,
*/
if (recurse)
{
Oid myrelid,
childrelid;
List *child,
*children;
if ((myrelid = RelnameFindRelid(relname)) == InvalidOid)
elog(ERROR, "renameatt: unknown relation: \"%s\"", relname);
/* this routine is actually in the planner */
children = find_all_inheritors(lconsi(myrelid, NIL), NIL);
children = find_all_inheritors(lconsi(relid, NIL), NIL);
/*
* find_all_inheritors does the recursive search of the
@ -100,10 +104,11 @@ renameatt(char *relname,
*/
foreach(child, children)
{
Oid childrelid;
char childname[NAMEDATALEN];
childrelid = lfirsti(child);
if (childrelid == myrelid)
if (childrelid == relid)
continue;
reltup = SearchSysCacheTuple(RELOID,
ObjectIdGetDatum(childrelid),
@ -117,14 +122,12 @@ renameatt(char *relname,
StrNCpy(childname,
((Form_pg_class) GETSTRUCT(reltup))->relname.data,
NAMEDATALEN);
/* no more recursion! */
/* note we need not recurse again! */
renameatt(childname, oldattname, newattname, userName, 0);
}
}
if ((relid = RelnameFindRelid(relname)) == InvalidOid)
elog(ERROR, "renameatt: relation \"%s\" nonexistent", relname);
attrelation = heap_openr(AttributeRelationName, RowExclusiveLock);
oldatttup = SearchSysCacheTupleCopy(ATTNAME,
ObjectIdGetDatum(relid),
@ -150,7 +153,6 @@ renameatt(char *relname,
StrNCpy((((Form_pg_attribute) (GETSTRUCT(oldatttup)))->attname.data),
newattname, NAMEDATALEN);
attrelation = heap_openr(AttributeRelationName);
heap_replace(attrelation, &oldatttup->t_self, oldatttup, NULL);
/* keep system catalog indices current */
@ -159,7 +161,7 @@ renameatt(char *relname,
CatalogCloseIndices(Num_pg_attr_indices, irelations);
pfree(oldatttup);
heap_close(attrelation);
heap_close(attrelation, RowExclusiveLock);
}
/*
@ -182,6 +184,7 @@ void
renamerel(char *oldrelname, char *newrelname)
{
int i;
Relation targetrelation;
Relation relrelation; /* for RELATION relation */
HeapTuple oldreltup;
char oldpath[MAXPGPATH],
@ -198,6 +201,15 @@ renamerel(char *oldrelname, char *newrelname)
elog(ERROR, "renamerel: Illegal class name: \"%s\" -- pg_ is reserved for system catalogs",
newrelname);
/*
* Grab an exclusive lock on the target table, which we will NOT release
* until end of transaction.
*/
targetrelation = heap_openr(oldrelname, AccessExclusiveLock);
heap_close(targetrelation, NoLock); /* close rel but keep lock! */
relrelation = heap_openr(RelationRelationName, RowExclusiveLock);
oldreltup = SearchSysCacheTupleCopy(RELNAME,
PointerGetDatum(oldrelname),
0, 0, 0);
@ -207,12 +219,17 @@ renamerel(char *oldrelname, char *newrelname)
if (RelnameFindRelid(newrelname) != InvalidOid)
elog(ERROR, "renamerel: relation \"%s\" exists", newrelname);
/*
* XXX need to close relation and flush dirty buffers here!
*/
/* rename the path first, so if this fails the rename's not done */
strcpy(oldpath, relpath(oldrelname));
strcpy(newpath, relpath(newrelname));
if (rename(oldpath, newpath) < 0)
elog(ERROR, "renamerel: unable to rename file: %s", oldpath);
/* rename additional segments of relation, too */
for (i = 1;; i++)
{
sprintf(toldpath, "%s.%d", oldpath, i);
@ -225,7 +242,6 @@ renamerel(char *oldrelname, char *newrelname)
newrelname, NAMEDATALEN);
/* insert fixed rel tuple */
relrelation = heap_openr(RelationRelationName);
heap_replace(relrelation, &oldreltup->t_self, oldreltup, NULL);
/* keep the system catalog indices current */
@ -233,5 +249,5 @@ renamerel(char *oldrelname, char *newrelname)
CatalogIndexInsert(irelations, Num_pg_class_indices, relrelation, oldreltup);
CatalogCloseIndices(Num_pg_class_indices, irelations);
heap_close(relrelation);
heap_close(relrelation, RowExclusiveLock);
}