Fix CREATE INDEX CONCURRENTLY to not deadlock against an automatic or manual

VACUUM that is blocked waiting to get lock on the table being indexed.
Per report and fix suggestion from Greg Stark.

diff --git a/src/backend/commands/indexcmds.c b/src/backend/commands/indexcmds.c
index efa25a1ad91b2d786808138e421ce0965331bfe7..952109f7845483f0c19e9de9940fbe90e60ee05d 100644 (file)
--- a/src/backend/commands/indexcmds.c
+++ b/src/backend/commands/indexcmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.169 2008/01/01 19:45:49 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.170 2008/01/09 21:52:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,6 +38,7 @@
 #include "parser/parse_expr.h"
 #include "parser/parse_func.h"
 #include "parser/parsetree.h"
+#include "storage/proc.h"
 #include "storage/procarray.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -630,11 +631,19 @@ DefineIndex(RangeVar *heapRelation,
         * We can exclude any running transactions that have xmin >= the xmax of
         * our reference snapshot, since they are clearly not interested in any
         * missing older tuples.  Transactions in other DBs aren't a problem
-        * either, since they'll never even be able to see this index. Also,
-        * GetCurrentVirtualXIDs never reports our own vxid, so we need not check
-        * for that.
+        * either, since they'll never even be able to see this index.
+        *
+        * We can also exclude autovacuum processes and processes running manual
+        * lazy VACUUMs, because they won't be fazed by missing index entries
+        * either.  (Manual ANALYZEs, however, can't be excluded because they
+        * might be within transactions that are going to do arbitrary operations
+        * later.)
+        *
+        * Also, GetCurrentVirtualXIDs never reports our own vxid, so we need not
+        * check for that.
         */
-       old_snapshots = GetCurrentVirtualXIDs(ActiveSnapshot->xmax, false);
+       old_snapshots = GetCurrentVirtualXIDs(ActiveSnapshot->xmax, false,
+                                                                                 PROC_IS_AUTOVACUUM | PROC_IN_VACUUM);
 
        while (VirtualTransactionIdIsValid(*old_snapshots))
        {

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 89441f64f1e2adc63fe5d801da85de4985b8b3ce..575b138c435b3ddf49e53b0bef8fc207cb4e0cb8 100644 (file)
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -23,7 +23,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.39 2008/01/01 19:45:51 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/storage/ipc/procarray.c,v 1.40 2008/01/09 21:52:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1006,10 +1006,12 @@ IsBackendPid(int pid)
  *
  * If limitXmin is not InvalidTransactionId, we skip any backends
  * with xmin >= limitXmin.     If allDbs is false, we skip backends attached
- * to other databases. Also, our own process is always skipped.
+ * to other databases.  If excludeVacuum isn't zero, we skip processes for
+ * which (excludeVacuum & vacuumFlags) is not zero.  Also, our own process
+ * is always skipped.
  */
 VirtualTransactionId *
-GetCurrentVirtualXIDs(TransactionId limitXmin, bool allDbs)
+GetCurrentVirtualXIDs(TransactionId limitXmin, bool allDbs, int excludeVacuum)
 {
        VirtualTransactionId *vxids;
        ProcArrayStruct *arrayP = procArray;
@@ -1029,6 +1031,9 @@ GetCurrentVirtualXIDs(TransactionId limitXmin, bool allDbs)
                if (proc == MyProc)
                        continue;
 
+               if (excludeVacuum & proc->vacuumFlags)
+                       continue;
+
                if (allDbs || proc->databaseId == MyDatabaseId)
                {
                        /* Fetch xmin just once - might change on us? */

diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index 5e0b1fd6ba57198a3ca4942f033191c0ac3aa5cc..26b27fa941806568c35e06ed5831047e8fd9df71 100644 (file)
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/storage/procarray.h,v 1.19 2008/01/01 19:45:59 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/storage/procarray.h,v 1.20 2008/01/09 21:52:36 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -37,7 +37,7 @@ extern int    BackendXidGetPid(TransactionId xid);
 extern bool IsBackendPid(int pid);
 
 extern VirtualTransactionId *GetCurrentVirtualXIDs(TransactionId limitXmin,
-                                         bool allDbs);
+                                         bool allDbs, int excludeVacuum);
 extern int     CountActiveBackends(void);
 extern int     CountDBBackends(Oid databaseid);
 extern int     CountUserBackends(Oid roleid);