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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2006-01-19 04:45:38 +0000 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2006-01-19 04:45:38 +0000 |
| commit | 4513d9dedac634aeca41a436093bc02a1aa8efec (patch) | |
| tree | 36a368426504d9a32e26db0f3913c382d1a6b7bb /src/include/storage | |
| parent | b0be247e38bdeb3911e70f5844bcbb48a1055917 (diff) | |
| download | postgresql-4513d9dedac634aeca41a436093bc02a1aa8efec.tar.gz | |
It turns out that TablespaceCreateDbspace fails badly if a relcache flush
occurs when it tries to heap_open pg_tablespace. When control returns to
smgrcreate, that routine will be holding a dangling pointer to a closed
SMgrRelation, resulting in mayhem. This is of course a consequence of
the violation of proper module layering inherent in having smgr.c call
a tablespace command routine, but the simplest fix seems to be to change
the locking mechanism. There's no real need for TablespaceCreateDbspace
to touch pg_tablespace at all --- it's only opening it as a way of locking
against a parallel DROP TABLESPACE command. A much better answer is to
create a special-purpose LWLock to interlock these two operations.
This drops TablespaceCreateDbspace quite a few layers down the food chain
and makes it something reasonably safe for smgr to call.
Diffstat (limited to 'src/include/storage')
| -rw-r--r-- | src/include/storage/lwlock.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/include/storage/lwlock.h b/src/include/storage/lwlock.h index ca384218a5..fb05544db1 100644 --- a/src/include/storage/lwlock.h +++ b/src/include/storage/lwlock.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/storage/lwlock.h,v 1.25 2006/01/04 21:06:32 tgl Exp $ + * $PostgreSQL: pgsql/src/include/storage/lwlock.h,v 1.26 2006/01/19 04:45:38 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -46,6 +46,7 @@ typedef enum LWLockId RelCacheInitLock, BgWriterCommLock, TwoPhaseStateLock, + TablespaceCreateLock, FirstLockMgrLock, /* must be last except for MaxDynamicLWLock */ MaxDynamicLWLock = 1000000000 |