orangefs: bufmap rewrite

new waiting-for-slot logics:
	* make request for slot wait for bufmap to be set up if it
comes before it's installed *OR* while it's running down
	* make closing control device wait for all slots to be freed
	* waiting itself rewritten to (open-coded) analogues of wait_event_...
primitives - we would need wait_event_locked() and, pardon an obscenely
long name, wait_event_interruptible_exclusive_timeout_locked().
	* we never wait for more than slot_timeout_secs in total and,
if during the wait the daemon goes away, we only allow
ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS for it to come back.
	* (cosmetical) bitmap is used instead of an array of zeroes and ones
	* old (and only reached if we are about to corrupt memory) waiting
for daemon restart in service_operation() removed.

[Martin's fixes folded]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

fs/orangefs/devorangefs-req.c

@@ -508,8 +508,7 @@ static int orangefs_devreq_release(struct inode *inode, struct file *file)
 		     __func__);
 
 	mutex_lock(&devreq_mutex);
-	if (orangefs_get_bufmap_init())
-		orangefs_bufmap_finalize();
+	orangefs_bufmap_finalize();
 
 	open_access_count = -1;
 
@@ -527,6 +526,9 @@ static int orangefs_devreq_release(struct inode *inode, struct file *file)
 	 * them as purged and wake them up
 	 */
 	purge_inprogress_ops();
+
+	orangefs_bufmap_run_down();
+
 	gossip_debug(GOSSIP_DEV_DEBUG,
 		     "pvfs2-client-core: device close complete\n");
 	open_access_count = 0;
@@ -607,13 +609,8 @@ static long dispatch_ioctl_command(unsigned int command, unsigned long arg)
 				     (struct ORANGEFS_dev_map_desc __user *)
 				     arg,
 				     sizeof(struct ORANGEFS_dev_map_desc));
-		if (orangefs_get_bufmap_init()) {
-			return -EINVAL;
-		} else {
-			return ret ?
-			       -EIO :
-			       orangefs_bufmap_initialize(&user_desc);
-		}
+		/* WTF -EIO and not -EFAULT? */
+		return ret ? -EIO : orangefs_bufmap_initialize(&user_desc);
 	case ORANGEFS_DEV_REMOUNT_ALL:
 		gossip_debug(GOSSIP_DEV_DEBUG,
 			     "%s: got ORANGEFS_DEV_REMOUNT_ALL\n",

fs/orangefs/orangefs-bufmap.h

@@ -15,10 +15,10 @@ int orangefs_bufmap_shift_query(void);
 
 int orangefs_bufmap_initialize(struct ORANGEFS_dev_map_desc *user_desc);
 
-int orangefs_get_bufmap_init(void);
-
 void orangefs_bufmap_finalize(void);
 
+void orangefs_bufmap_run_down(void);
+
 int orangefs_bufmap_get(struct orangefs_bufmap **mapp, int *buffer_index);
 
 void orangefs_bufmap_put(int buffer_index);

fs/orangefs/waitqueue.c

@@ -155,67 +155,6 @@ int service_operation(struct orangefs_kernel_op_s *op,
 			 * system
 			 */
 			goto retry_servicing;
-
-		/* op uses shared memory */
-		if (orangefs_get_bufmap_init() == 0) {
-			WARN_ON(1);
-			/*
-			 * This operation uses the shared memory system AND
-			 * the system is not yet ready. This situation occurs
-			 * when the client-core is restarted AND there were
-			 * operations waiting to be processed or were already
-			 * in process.
-			 */
-			gossip_debug(GOSSIP_WAIT_DEBUG,
-				     "uses_shared_memory is true.\n");
-			gossip_debug(GOSSIP_WAIT_DEBUG,
-				     "Client core in-service status(%d).\n",
-				     is_daemon_in_service());
-			gossip_debug(GOSSIP_WAIT_DEBUG, "bufmap_init:%d.\n",
-				     orangefs_get_bufmap_init());
-			gossip_debug(GOSSIP_WAIT_DEBUG,
-				     "operation's status is 0x%0x.\n",
-				     op->op_state);
-
-			/*
-			 * let process sleep for a few seconds so shared
-			 * memory system can be initialized.
-			 */
-			prepare_to_wait(&orangefs_bufmap_init_waitq,
-					&wait_entry,
-					TASK_INTERRUPTIBLE);
-
-			/*
-			 * Wait for orangefs_bufmap_initialize() to wake me up
-			 * within the allotted time.
-			 */
-			ret = schedule_timeout(
-				ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS * HZ);
-
-			gossip_debug(GOSSIP_WAIT_DEBUG,
-				     "Value returned from schedule_timeout:"
-				     "%d.\n",
-				     ret);
-			gossip_debug(GOSSIP_WAIT_DEBUG,
-				     "Is shared memory available? (%d).\n",
-				     orangefs_get_bufmap_init());
-
-			finish_wait(&orangefs_bufmap_init_waitq, &wait_entry);
-
-			if (orangefs_get_bufmap_init() == 0) {
-				gossip_err("%s:The shared memory system has not started in %d seconds after the client core restarted.  Aborting user's request(%s).\n",
-					   __func__,
-					   ORANGEFS_BUFMAP_WAIT_TIMEOUT_SECS,
-					   get_opname_string(op));
-				return -EIO;
-			}
-
-			/*
-			 * Return to the calling function and re-populate a
-			 * shared memory buffer.
-			 */
-			return -EAGAIN;
-		}
 	}
 
 out: