Fix reference count problem

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@258 42af7a65-404d-4744-a932-0658087f49c3

3 files changed, 50 insertions, 13 deletions

diff --git a/nuttx/fs/fs_fat32.c b/nuttx/fs/fs_fat32.c
index e8677e1be..098353cd5 100644
--- a/nuttx/fs/fs_fat32.c
+++ b/nuttx/fs/fs_fat32.c
@@ -91,7 +91,7 @@ static int     fat_rewinddir(struct inode *mountpt, struct internal_dir_s *dir);
 
 static int     fat_bind(FAR struct inode *blkdriver, const void *data,
                         void **handle);
-static int     fat_unbind(void *handle);
+static int     fat_unbind(void *handle, FAR struct inode **blkdriver);
 static int     fat_unlink(struct inode *mountpt, const char *relpath);
 static int     fat_mkdir(struct inode *mountpt, const char *relpath,
                          mode_t mode);
@@ -1517,7 +1517,7 @@ static int fat_bind(FAR struct inode *blkdriver, const void *data,
  *
  ****************************************************************************/
 
-static int fat_unbind(void *handle)
+static int fat_unbind(void *handle, FAR struct inode **blkdriver)
 {
   struct fat_mountpt_s *fs = (struct fat_mountpt_s*)handle;
   int ret;
@@ -1551,9 +1551,16 @@ static int fat_unbind(void *handle)
                   (void)inode->u.i_bops->close(inode);
                 }
 
-              /* Release our reference to the block driver */
+              /* We hold a reference to the block driver but should
+               * not but mucking with inodes in this context.  So, we will just return
+               * our contained reference to the block driver inode and let the umount
+               * logic dispose of it.
+               */
 
-              inode_release(inode);
+              if (blkdriver)
+                {
+                  *blkdriver = inode;
+                }
             }
         }
 
diff --git a/nuttx/fs/fs_inoderemove.c b/nuttx/fs/fs_inoderemove.c
index 633222567..c227cfacc 100644
--- a/nuttx/fs/fs_inoderemove.c
+++ b/nuttx/fs/fs_inoderemove.c
@@ -136,6 +136,7 @@ STATUS inode_remove(const char *path)
             */
 
            node->i_flags |= FSNODEFLAG_DELETED;
+           return -EBUSY;
          }
        else
          {
@@ -149,5 +150,5 @@ STATUS inode_remove(const char *path)
 
   /* The node does not exist or it has references */
 
-  return ERROR;
+  return -ENOENT;
 }
diff --git a/nuttx/fs/fs_umount.c b/nuttx/fs/fs_umount.c
index 347719982..d6a6351f4 100644
--- a/nuttx/fs/fs_umount.c
+++ b/nuttx/fs/fs_umount.c
@@ -92,7 +92,8 @@
 int umount(const char *target)
 {
   FAR struct inode *mountpt_inode;
-  int errcode;
+  FAR struct inode *blkdrvr_inode = NULL;
+  int errcode = OK;
   int status;
 
   /* Verify required pointer arguments */
@@ -138,7 +139,7 @@ int umount(const char *target)
    */
 
   inode_semtake(); /* Hold the semaphore through the unbind logic */
-  status = mountpt_inode->u.i_mops->unbind( mountpt_inode->i_private );
+  status = mountpt_inode->u.i_mops->unbind( mountpt_inode->i_private, &blkdrvr_inode);
   if (status < 0)
     {
       /* The inode is unhappy with the blkdrvr for some reason */
@@ -156,15 +157,39 @@ int umount(const char *target)
 
   mountpt_inode->i_private = NULL;
 
-  /* Remove the inode */
-
-  inode_semgive(); /* Need to release for inode_release */
-  inode_release(mountpt_inode);
+  /* Successfully unbound, remove the mountpoint inode from
+   * the inode tree.  The inode will not be deleted yet because
+   * there is still at least reference on it (from the mount)
+   */
 
-  inode_semtake(); /* Need to hold for inode_remove */
   status = inode_remove(target);
   inode_semgive();
-  return status;
+
+  /* The return value of -EBUSY is normal (in fact, it should
+   * not be OK)
+   */
+
+  if (status != OK && status != -EBUSY)
+    {
+      errcode = -status;
+      goto errout_with_mountpt;
+    }
+
+  /* Release the mountpoint inode and any block driver inode
+   * returned by the file system unbind above.  This should cause
+   * the inode to be deleted (unless there are other references)
+   */
+
+  inode_release(mountpt_inode);
+
+  /* Did the unbind method return a contained block driver */
+
+  if (blkdrvr_inode)
+    {
+      inode_release(blkdrvr_inode);
+    }
+
+  return OK;
 
   /* A lot of goto's!  But they make the error handling much simpler */
 
@@ -172,6 +197,10 @@ int umount(const char *target)
   inode_semgive();
  errout_with_mountpt:
   inode_release(mountpt_inode);
+  if (blkdrvr_inode)
+    {
+      inode_release(blkdrvr_inode);
+    }
  errout:
   *get_errno_ptr() = errcode;
   return ERROR;