Fix typos in comments.

Backpatch to all supported versions, where applicable, to make backpatching
of future fixes go more smoothly.

Josh Soref

Discussion: https://www.postgresql.org/message-id/CACZqfqCf+5qRztLPgmmosr-B0Ye4srWzzw_mo4c_8_B_mtjmJQ@mail.gmail.com

src/backend/storage/ipc/shm_mq.c

@@ -472,7 +472,7 @@ shm_mq_sendv(shm_mq_handle *mqh, shm_mq_iovec *iov, int iovcnt, bool nowait)
  * it will point to a temporary buffer.  This mostly avoids data copying in
  * the hoped-for case where messages are short compared to the buffer size,
  * while still allowing longer messages.  In either case, the return value
- * remains valid until the next receive operation is perfomed on the queue.
+ * remains valid until the next receive operation is performed on the queue.
  *
  * When nowait = false, we'll wait on our process latch when the ring buffer
  * is empty and we have not yet received a full message.  The sender will

src/backend/storage/lmgr/lock.c

@@ -2697,7 +2697,7 @@ GetLockConflicts(const LOCKTAG *locktag, LOCKMODE lockmode)
 		vxids = (VirtualTransactionId *)
 			palloc0(sizeof(VirtualTransactionId) * (MaxBackends + 1));
 
-	/* Compute hash code and partiton lock, and look up conflicting modes. */
+	/* Compute hash code and partition lock, and look up conflicting modes. */
 	hashcode = LockTagHashCode(locktag);
 	partitionLock = LockHashPartitionLock(hashcode);
 	conflictMask = lockMethodTable->conflictTab[lockmode];

src/backend/storage/lmgr/lwlock.c

@@ -636,7 +636,7 @@ LWLockAttemptLock(LWLock *lock, LWLockMode mode)
 				return false;
 			}
 			else
-				return true;	/* someobdy else has the lock */
+				return true;	/* somebody else has the lock */
 		}
 	}
 	pg_unreachable();
@@ -733,7 +733,7 @@ LWLockWakeup(LWLock *lock)
 		 * that happens before the list unlink happens, the list would end up
 		 * being corrupted.
 		 *
-		 * The barrier pairs with the SpinLockAcquire() when enqueing for
+		 * The barrier pairs with the SpinLockAcquire() when enqueuing for
 		 * another lock.
 		 */
 		pg_write_barrier();
@@ -823,7 +823,7 @@ LWLockDequeueSelf(LWLock *lock)
 
 	/*
 	 * Can't just remove ourselves from the list, but we need to iterate over
-	 * all entries as somebody else could have unqueued us.
+	 * all entries as somebody else could have dequeued us.
 	 */
 	dlist_foreach_modify(iter, &lock->waiters)
 	{

src/backend/storage/lmgr/predicate.c

@@ -3203,7 +3203,7 @@ ReleasePredicateLocks(bool isCommit)
 	/*
 	 * We can't trust XactReadOnly here, because a transaction which started
 	 * as READ WRITE can show as READ ONLY later, e.g., within
-	 * substransactions.  We want to flag a transaction as READ ONLY if it
+	 * subtransactions.  We want to flag a transaction as READ ONLY if it
 	 * commits without writing so that de facto READ ONLY transactions get the
 	 * benefit of some RO optimizations, so we will use this local variable to
 	 * get some cleanup logic right which is based on whether the transaction