Changeset 12a56fa in mainline

Timestamp:

2007-09-28T14:44:23Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

90e6025

Parents:

84b86dcb

Message:

VFS work.

Modify vfs_lookup_internal() to be able to work with an alternate root. This
will be useful for VFS_MOUNT support.

Improve observability and debuggability by explicitly zeroing out PLB after the
path has been looked up.

Location:

uspace/srv/vfs

Files:

• vfs.h (modified) (1 diff)
• vfs_lookup.c (modified) (3 diffs)
• vfs_register.c (modified) (1 diff)

uspace/srv/vfs/vfs.h

@@ -150 +150 @@
 extern int fs_name_to_handle(char *name, bool lock);
 
-extern int vfs_lookup_internal(char *path, size_t len, vfs_node_t *result);
+extern int vfs_lookup_internal(char *path, size_t len, vfs_node_t *result,
+    vfs_node_t *altroot);
 
 extern void vfs_register(ipc_callid_t, ipc_call_t *);

uspace/srv/vfs/vfs_lookup.c

@@ -52 +52 @@
 uint8_t *plb = NULL;
 
-int vfs_lookup_internal(char *path, size_t len, vfs_node_t *result)
+/** Perform a path lookup.
+ *
+ * @param path          Path to be resolved; it needn't be an ASCIIZ string.
+ * @param len           Number of path characters pointed by path.
+ * @param result        Empty node structure where the result will be stored.
+ * @param altroot       If non-empty, will be used instead of rootfs as the root
+ *                      of the whole VFS tree.
+ *
+ * @return              EOK on success or an error code from errno.h.
+ */
+int vfs_lookup_internal(char *path, size_t len, vfs_node_t *result,
+    vfs_node_t *altroot)
 {
+        vfs_node_t *root;
+
         if (!len)
                 return EINVAL;
 
-        if (!rootfs)
+        if (altroot)
+                root = altroot;
+        else
+                root = rootfs;
+
+        if (!root)
                 return ENOENT;
         
@@ -126 +144 @@
 
         ipc_call_t answer;
-        int phone = vfs_grab_phone(rootfs->fs_handle);
+        int phone = vfs_grab_phone(root->fs_handle);
         aid_t req = async_send_3(phone, VFS_LOOKUP, (ipcarg_t) first,
-            (ipcarg_t) last, (ipcarg_t) rootfs->dev_handle, &answer);
+            (ipcarg_t) last, (ipcarg_t) root->dev_handle, &answer);
         vfs_release_phone(phone);
 
@@ -136 +154 @@
         futex_down(&plb_futex);
         list_remove(&entry.plb_link);
+        /*
+         * Erasing the path from PLB will come handy for debugging purposes.
+         */
+        memset(&plb[first], 0, cnt1);
+        memset(plb, 0, cnt2);
         futex_up(&plb_futex);
 

uspace/srv/vfs/vfs_register.c

@@ -290 +290 @@
                 ipc_answer_fast(rid, EINVAL, 0, 0);
                 return;
-                
         }