Completes the re-implementation of mq_unlink()

fs/mqueue/mq_close.c

 /****************************************************************************
- *  sched/mqueue/mq_close.c
+ *  fs/mqueue/mq_close.c
  *
- *   Copyright (C) 2007, 2009, 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2013-2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -107,7 +107,7 @@ int mq_close(mqd_t mqdes)
   FAR struct tcb_s *rtcb = sched_self();
   FAR struct task_group_s *group = rtcb->group;
   FAR struct mqueue_inode_s *msgq;
-  struct inode *inode ;
+  FAR struct inode *inode;
 
   DEBUGASSERT(group);
 
@@ -128,11 +128,6 @@ int mq_close(mqd_t mqdes)
        msgq = mqdes->msgq;
        DEBUGASSERT(msgq && msgq->inode);
 
-       /* Get the inode from the message queue structure */
-
-       inode = msgq->inode;
-       DEBUGASSERT(inode->u.i_mqueue == msgq);
-
        /* Check if the calling task has a notification attached to
         * the message queue via this mqdes.
         */
@@ -147,40 +142,65 @@ int mq_close(mqd_t mqdes)
          }
 #endif
 
+       /* Get the inode from the message queue structure */
+
+       inode = msgq->inode;
+       DEBUGASSERT(inode->u.i_mqueue == msgq);
+
        /* Decrement the reference count on the inode */
 
-       inode_semtake();
-       if (inode->i_crefs > 0)
-         {
-           inode->i_crefs--;
-         }
+       mq_release(inode);
+     }
 
-      /* If the message queue was previously unlinked and the reference
-       * count has decremented to zero, then release the message queue and
-       * delete the inode now.
-        */
+  return OK;
+}
 
-       if (inode->i_crefs <= 0 && (inode->i_flags & FSNODEFLAG_DELETED) != 0)
-         {
-           /* Free the message queue (and any messages left in it) */
+/****************************************************************************
+ * Name: mq_close
+ *
+ * Description:
+ *   Release a reference count on a message queue inode.
+ *
+ * Parameters:
+ *   inode - The message queue inode
+ *
+ * Return Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void mq_release(FAR struct inode *inode)
+{
+  /* Decrement the reference count on the inode */
 
-           mq_msgqfree(msgq);
+  inode_semtake();
+  if (inode->i_crefs > 0)
+    {
+      inode->i_crefs--;
+    }
 
-           /* Release and free the inode container */
+  /* If the message queue was previously unlinked and the reference count
+   * has decremented to zero, then release the message queue and delete
+   * the inode now.
+   */
 
-           inode_semgive();
-           inode_free(inode->i_child);
-           kmm_free(inode);
-           return OK;
-        }
+   if (inode->i_crefs <= 0 && (inode->i_flags & FSNODEFLAG_DELETED) != 0)
+     {
+       FAR struct mqueue_inode_s *msgq = inode->u.i_mqueue;
+       DEBUGASSERT(msgq);
+
+       /* Free the message queue (and any messages left in it) */
 
-       /* Deallocate the message descriptor */
+       mq_msgqfree(msgq);
+       inode->u.i_mqueue = NULL;
 
-       mq_desfree(mqdes);
+       /* Release and free the inode container */
 
-       sched_unlock();
        inode_semgive();
-     }
+       inode_free(inode->i_child);
+       kmm_free(inode);
+       return;
+    }
 
-  return OK;
+  inode_semgive();
 }

fs/mqueue/mq_open.c

 /****************************************************************************
- *  sched/mqueue/mq_open.c
+ *  fs/mqueue/mq_open.c
  *
  *   Copyright (C) 2007-2009, 2011, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
@@ -64,11 +64,6 @@
 /****************************************************************************
  * Pre-procesor Definitions
  ****************************************************************************/
-/* Configuration ************************************************************/
-
-#ifndef CONFIG_FS_MQUEUE_MPATH
-#  define CONFIG_FS_MQUEUE_MPATH "/var/mqueue"
-#endif
 
 /****************************************************************************
  * Private Type Declarations

fs/mqueue/mq_unlink.c

 /************************************************************************
- * sched/mqueue/mq_unlink.c
+ * fs/mqueue/mq_unlink.c
  *
- *   Copyright (C) 2007, 2009 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007, 2009, 2014 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
@@ -39,10 +39,14 @@
 
 #include <nuttx/config.h>
 
-#include <stdbool.h>
+#include <stdio.h>
 #include <mqueue.h>
-#include <sched.h>
+#include <assert.h>
+#include <errno.h>
 
+#include <nuttx/mqueue.h>
+
+#include "inode/inode.h"
 #include "mqueue/mqueue.h"
 
 /************************************************************************
@@ -88,58 +92,80 @@
  *
  ************************************************************************/
 
-int mq_unlink(const char *mq_name)
+int mq_unlink(FAR const char *mq_name)
 {
-  FAR struct mqueue_inode_s *msgq;
-  irqstate_t saved_state;
-  int ret = ERROR;
-
-  /* Verify the input values */
-
-  if (mq_name)
-    {
-      sched_lock();
-
-      /* Find the named message queue */
+  FAR struct inode *inode;
+  FAR const char *relpath = NULL;
+  char fullpath[MAX_MQUEUE_PATH];
+  int errcode;
+  int ret;
 
-      msgq = mq_findnamed(mq_name);
-      if (msgq)
-        {
-          /* If it is no longer connected, then we can just
-           * discard the message queue now.
-           */
+  /* Get the full path to the message queue */
 
-          if (!msgq->nconnect)
-            {
-              /* Remove the message queue from the list of all
-               * message queues
-               */
+  snprintf(fullpath, MAX_MQUEUE_PATH, CONFIG_FS_MQUEUE_MPATH "/%s", mq_name);
 
-              saved_state = irqsave();
-              (void)sq_rem((FAR sq_entry_t*)msgq, &g_msgqueues);
-              irqrestore(saved_state);
+  /* Get the inode for this message queue. */
 
-              /* Then deallocate it (and any messages left in it) */
+  sched_lock();
+  inode = inode_find(fullpath, &relpath);
+  if (!inode)
+    {
+      /* There is no inode that includes in this path */
 
-              mq_msgqfree(msgq);
-            }
+      errcode = ENOENT;
+      goto errout;
+    }
 
-          /* If the message queue is still connected to a message descriptor,
-           * then mark it for deletion when the last message descriptor is
-           * closed
-           */
+  /* Verify that what we found is, indeed, a message queue */
 
-          else
-            {
-              msgq->unlinked = true;
-            }
+  if (!INODE_IS_MQUEUE(inode))
+    {
+      errcode = ENXIO;
+      goto errout_with_inode;
+    }
 
-          ret = OK;
-        }
+  /* Refuse to unlink the inode if it has children.  I.e., if it is
+   * functioning as a directory and the directory is not empty.
+   */
 
-      sched_unlock();
+  inode_semtake();
+  if (inode->i_child != NULL)
+    {
+      errcode = ENOTEMPTY;
+      goto errout_with_semaphore;
     }
 
-  return ret;
+  /* Remove the old inode from the tree.  Because we hold a reference count
+   * on the inode, it will not be deleted now.  This will set the
+   * FSNODEFLAG_DELETED bit in the inode flags.
+   */
+
+  ret = inode_remove(fullpath);
+
+  /* inode_remove() should always fail with -EBUSY because we hae a reference
+   * on the inode.  -EBUSY means taht the inode was, indeed, unlinked but
+   * thatis could not be freed because there are refrences.
+   */
+
+  DEBUGASSERT(ret >= 0 || ret == -EBUSY);
+  UNUSED(ret);
+
+  /* Now we do not release the reference count in the normal way (by calling
+   * inode release.  Rather, we call sem_close().  sem_close will decrement
+   * the reference count on the inode.  But it will also free the message queue
+   * if that reference count decrements to zero.  Since we hold one reference,
+   * that can only occur if the message queue is not in-use.
+   */
+
+  inode_semgive();
+  mq_release(inode);
+  return OK;
+
+errout_with_semaphore:
+  inode_semgive();
+errout_with_inode:
+  inode_release(inode);
+errout:
+  set_errno(errcode);
+  return ERROR;
 }
-

fs/mqueue/mqueue.h

@@ -45,6 +45,13 @@
 /****************************************************************************
  * Pre-processor Definitions
  ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_FS_MQUEUE_MPATH
+#  define CONFIG_FS_MQUEUE_MPATH "/var/mqueue"
+#endif
+
+/* Sizes of things */
 
 #define MAX_MQUEUE_PATH 64
 
@@ -68,6 +75,22 @@ extern "C"
  * Public Function Prototypes
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: mq_close
+ *
+ * Description:
+ *   Release a reference count on a message queue inode.
+ *
+ * Parameters:
+ *   inode - The message queue inode
+ *
+ * Return Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void mq_release(FAR struct inode *inode);
+
 #undef EXTERN
 #ifdef __cplusplus
 }

fs/semaphore/sem_unlink.c

@@ -99,7 +99,7 @@
 int sem_unlink(FAR const char *name)
 {
   FAR struct inode *inode;
-  FAR const char  *relpath = NULL;
+  FAR const char *relpath = NULL;
   char fullpath[MAX_SEMPATH];
   int errcode;
   int ret;