remove some excess parens. rearrange lock ordering slightly.

diff --git a/src/backend/access/conveyor/conveyor.c b/src/backend/access/conveyor/conveyor.c
index 7261c48c12bfa4370d247e07d9b55377b4086242..47aa979a0e6ff70fd93ccb66931f5d63607d1b11 100644 (file)
--- a/src/backend/access/conveyor/conveyor.c
+++ b/src/backend/access/conveyor/conveyor.c
@@ -280,8 +280,8 @@ ConveyorBeltGetNewPage(ConveyorBelt *cb, CBPageNo *pageno)
                        (insert_state == CBM_INSERT_NEEDS_PAYLOAD_SEGMENT
                         || insert_state == CBM_INSERT_NEEDS_INDEX_SEGMENT) &&
                        mode == BUFFER_LOCK_EXCLUSIVE &&
-                       (free_segno != CB_INVALID_SEGMENT) &&
-                       (free_segno < possibly_not_on_disk_segno);
+                       free_segno != CB_INVALID_SEGMENT &&
+                       free_segno < possibly_not_on_disk_segno;
 
                /*
                 * If it still looks like we can allocate, check for the case where we
@@ -421,11 +421,17 @@ ConveyorBeltGetNewPage(ConveyorBelt *cb, CBPageNo *pageno)
                                                                                        next_blkno, nblocks));
                                else if (next_blkno == nblocks)
                                {
+                                       /* relase extension lock before locking buffer */
                                        buffer = ReadBufferExtended(cb->cb_rel, cb->cb_fork,
                                                                                                P_NEW, RBM_NORMAL, NULL);
+                                       UnlockRelationForExtension(cb->cb_rel, ExclusiveLock);
                                        LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
                                }
-                               UnlockRelationForExtension(cb->cb_rel, ExclusiveLock);
+                               else
+                               {
+                                       /* we don't need to extend */
+                                       UnlockRelationForExtension(cb->cb_rel, ExclusiveLock);
+                               }
                        }
 
                        /* If we didn't extend the relation, just read the buffer. */