Filesystem: Reject removal of root nodes

Reject the removal of file system instance root nodes in rmdir() and
unlink() and return the EBUSY error status.  File system instances can
be removed with unmount().  Remove root node special cases in IMFS,
DOSFS, and RFS.

cpukit/libcsupport/src/rmdir.c

@@ -38,7 +38,12 @@ int rmdir( const char *path )
   rtems_filesystem_node_types_t type = (*ops->node_type_h)( currentloc );
 
   if ( type == RTEMS_FILESYSTEM_DIRECTORY ) {
-    rv = (*ops->rmnod_h)( &parentloc, currentloc );
+    if ( !rtems_filesystem_location_is_root( currentloc ) ) {
+      rv = (*ops->rmnod_h)( &parentloc, currentloc );
+    } else {
+      rtems_filesystem_eval_path_error( &ctx, EBUSY );
+      rv = -1;
+    }
   } else {
     rtems_filesystem_eval_path_error( &ctx, ENOTDIR );
     rv = -1;

cpukit/libcsupport/src/unlink.c

@@ -34,9 +34,15 @@ int unlink( const char *path )
       &parentloc,
       parent_eval_flags
     );
-  const rtems_filesystem_operations_table *ops = currentloc->mt_entry->ops;
 
-  rv = (*ops->rmnod_h)( &parentloc, currentloc );
+  if ( !rtems_filesystem_location_is_root( currentloc ) ) {
+    const rtems_filesystem_operations_table *ops = currentloc->mt_entry->ops;
+
+    rv = (*ops->rmnod_h)( &parentloc, currentloc );
+  } else {
+    rtems_filesystem_eval_path_error( &ctx, EBUSY );
+    rv = -1;
+  }
 
   rtems_filesystem_eval_path_cleanup_with_parent( &ctx, &parentloc );
 

cpukit/libfs/src/dosfs/msdos_rmnod.c

@@ -50,14 +50,6 @@ msdos_rmnod(const rtems_filesystem_location_info_t *parent_pathloc,
             rtems_set_errno_and_return_minus_one(EBUSY);
         }
 
-        /*
-         * You cannot remove the file system root node.
-         */
-        if (rtems_filesystem_location_is_root(pathloc))
-        {
-            rtems_set_errno_and_return_minus_one(EBUSY);
-        }
-
         /*
          * You cannot remove a mountpoint.
          * not used - mount() not implemenetd yet.

cpukit/libfs/src/imfs/imfs.h

@@ -169,13 +169,11 @@ IMFS_jnode_t *IMFS_node_initialize_generic(
 );
 
 typedef IMFS_jnode_t *(*IMFS_node_control_remove)(
-  IMFS_jnode_t *node,
-  const IMFS_jnode_t *root_node
+  IMFS_jnode_t *node
 );
 
 IMFS_jnode_t *IMFS_node_remove_default(
-  IMFS_jnode_t *node,
-  const IMFS_jnode_t *root_node
+  IMFS_jnode_t *node
 );
 
 typedef IMFS_jnode_t *(*IMFS_node_control_destroy)( IMFS_jnode_t *node );

cpukit/libfs/src/imfs/imfs_handlers_directory.c

@@ -74,14 +74,13 @@ static bool IMFS_is_mount_point( const IMFS_jnode_t *node )
 }
 
 static IMFS_jnode_t *IMFS_node_remove_directory(
-  IMFS_jnode_t *node,
-  const IMFS_jnode_t *root_node
+  IMFS_jnode_t *node
 )
 {
   if ( !rtems_chain_is_empty( &node->info.directory.Entries ) ) {
     errno = ENOTEMPTY;
     node = NULL;
-  } else if ( node == root_node || IMFS_is_mount_point( node ) ) {
+  } else if ( IMFS_is_mount_point( node ) ) {
     errno = EBUSY;
     node = NULL;
   }

cpukit/libfs/src/imfs/imfs_handlers_link.c

@@ -64,14 +64,13 @@ static IMFS_jnode_t *IMFS_node_initialize_hard_link(
 }
 
 static IMFS_jnode_t *IMFS_node_remove_hard_link(
-  IMFS_jnode_t *node,
-  const IMFS_jnode_t *root_node
+  IMFS_jnode_t *node
 )
 {
   IMFS_jnode_t *target = node->info.hard_link.link_node;
 
   if ( target->st_nlink == 1) {
-    target = (*target->control->node_remove)( target, root_node );
+    target = (*target->control->node_remove)( target );
     if ( target == NULL ) {
       node = NULL;
     }

cpukit/libfs/src/imfs/imfs_initsupp.c

@@ -141,8 +141,7 @@ IMFS_jnode_t *IMFS_node_initialize_default(
 }
 
 IMFS_jnode_t *IMFS_node_remove_default(
-  IMFS_jnode_t *node,
-  const IMFS_jnode_t *root_node
+  IMFS_jnode_t *node
 )
 {
   return node;

cpukit/libfs/src/imfs/imfs_rmnod.c

@@ -29,10 +29,7 @@ int IMFS_rmnod(
   int rv = 0;
   IMFS_jnode_t *node = loc->node_access;
 
-  node = (*node->control->node_remove)(
-    node,
-    loc->mt_entry->mt_fs_root->location.node_access
-  );
+  node = (*node->control->node_remove)( node );
   if ( node != NULL ) {
     --node->reference_count;
     --node->st_nlink;

cpukit/libfs/src/rfs/rtems-rfs-rtems.c

@@ -678,9 +678,6 @@ rtems_rfs_rtems_rmnod (const rtems_filesystem_location_info_t* parent_pathloc,
     printf ("rtems-rfs: rmnod: parent:%" PRId32 " doff:%" PRIu32 ", ino:%" PRId32 "\n",
             parent, doff, ino);
 
-  if (ino == RTEMS_RFS_ROOT_INO)
-    return rtems_rfs_rtems_error ("rmnod: root inode", EBUSY);
-
   rc = rtems_rfs_unlink (fs, parent, ino, doff, rtems_rfs_unlink_dir_if_empty);
   if (rc)
   {

testsuites/fstests/fsimfsgeneric01/init.c

@@ -233,10 +233,7 @@ static IMFS_jnode_t *node_initialize(
   return node;
 }
 
-static IMFS_jnode_t *node_remove(
-  IMFS_jnode_t *node,
-  const IMFS_jnode_t *root_node
-)
+static IMFS_jnode_t *node_remove(IMFS_jnode_t *node)
 {
   test_state *state = IMFS_generic_get_context_by_node(node);