Changes between Version 7 and Version 8 of FSDesign

Timestamp:

2009-07-23T19:26:55Z (15 years ago)

Author:

Jakub Jermář

Comment:

—

FSDesign

@@ -65 +65 @@
 adds a reference to an existing one. VFS nodes are organized in a hash table with
 the VFS triplet as a search key.
+
+The following example illustrates how the VFS server obtains the VFS node in the
+implementation of the unlink operation:
+
+{{{
+        int rc;
+        int lflag = ...;
+        char *path = ...;    /* file path */
+        ...
+        vfs_lookup_res_t lr;
+        rc = vfs_lookup_internal(path, lflag | L_UNLINK, &lr, NULL);
+        if (rc != EOK) {
+             /* handle error */
+             ...
+        }
+   
+        vfs_node_t *node = vfs_node_get(&lr);
+        /* now we have a reference to the node and work with it */
+        ...
+        vfs_node_put(node);
+}}}
+
+The example is simplified and does not show all the details (e.g. it omits all synchronization), but it shows the main idea. Note the trailing ''vfs_node_put()'' function which drops a reference to a VFS node. If the last reference is dropped from a node, ''vfs_node_put()'' removes it from the hash table and cleans it up.