Changeset b5553a2 in mainline

Timestamp:

2008-02-16T11:23:19Z (16 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

f17667a

Parents:

8ccd2ea

Message:

Introduce the notion of VFS node link counts.

Location:

uspace/srv

Files:

• fs/tmpfs/tmpfs_ops.c (modified) (7 diffs)
• vfs/vfs.h (modified) (2 diffs)
• vfs/vfs_lookup.c (modified) (1 diff)
• vfs/vfs_node.c (modified) (2 diffs)

uspace/srv/fs/tmpfs/tmpfs_ops.c

@@ -59 +59 @@
 #define DENTRIES_BUCKETS        256
 
+#define TMPFS_GET_INDEX(x)      (((tmpfs_dentry_t *)(x))->index)
+#define TMPFS_GET_LNKCNT(x)     1
+
 /*
  * Hash table of all directory entries.
@@ -128 +131 @@
 /** Compare one component of path to a directory entry.
  *
- * @param dentry        Directory entry to compare the path component with.
+ * @param nodep         Node to compare the path component with.
  * @param component     Array of characters holding component name.
  *
  * @return              True on match, false otherwise.
  */
-static bool match_component(tmpfs_dentry_t *dentry, const char *component)
-{
+static bool match_component(void *nodep, const char *component)
+{
+        tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
+
         return !strcmp(dentry->name, component);
 }
 
-static unsigned long create_node(tmpfs_dentry_t *dentry,
+static void *create_node(void *nodep,
     const char *component, int lflag)
 {
+        tmpfs_dentry_t *dentry = (tmpfs_dentry_t *) nodep;
+
         assert(dentry->type == TMPFS_DIRECTORY);
         assert((lflag & L_FILE) ^ (lflag & L_DIRECTORY));
@@ -146 +153 @@
         tmpfs_dentry_t *node = malloc(sizeof(tmpfs_dentry_t));
         if (!node)
-                return 0;
+                return NULL;
         size_t len = strlen(component);
         char *name = malloc(len + 1);
         if (!name) {
                 free(node);
-                return 0;
+                return NULL;
         }
         strcpy(name, component);
@@ -176 +183 @@
         /* Insert the new node into the dentry hash table. */
         hash_table_insert(&dentries, &node->index, &node->dh_link);
-        return node->index;
-}
-
-static int destroy_component(tmpfs_dentry_t *dentry)
+        return (void *) node;
+}
+
+static int destroy_component(void *nodeptr)
 {
         return EPERM;
@@ -242 +249 @@
                                         return;
                                 } 
-                                unsigned long index = create_node(dcur,
+                                void *nodep = create_node(dcur,
                                     component, lflag);
-                                if (index > 0) {
-                                        ipc_answer_4(rid, EOK,
+                                if (nodep) {
+                                        ipc_answer_5(rid, EOK,
                                             tmpfs_reg.fs_handle, dev_handle,
-                                            index, 0);
+                                            TMPFS_GET_INDEX(nodep), 0,
+                                            TMPFS_GET_LNKCNT(nodep));
                                 } else {
                                         ipc_answer_0(rid, ENOSPC);
@@ -289 +297 @@
                         len = 0;
                                 
-                        unsigned long index;
-                        index = create_node(dcur, component, lflag);
-                        if (index) {
-                                ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle,
-                                    dev_handle, index, 0);
+                        void *nodep = create_node(dcur, component, lflag);
+                        if (nodep) {
+                                ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle,
+                                    dev_handle, TMPFS_GET_INDEX(nodep), 0,
+                                    TMPFS_GET_LNKCNT(nodep));
                         } else {
                                 ipc_answer_0(rid, ENOSPC);
@@ -322 +330 @@
         }
 
-        ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
-            dcur->size);
+        ipc_answer_5(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
+            dcur->size, TMPFS_GET_LNKCNT(dcur));
 }
 

uspace/srv/vfs/vfs.h

@@ -174 +174 @@
         vfs_triplet_t triplet;
         size_t size;
+        unsigned lnkcnt;
 } vfs_lookup_res_t;
 
@@ -182 +183 @@
 typedef struct {
         VFS_TRIPLET;            /**< Identity of the node. */
-        unsigned refcnt;        /**< Usage counter. */
+
+        /**
+         * Usage counter.  This includes, but is not limited to, all vfs_file_t
+         * structures that reference this node.
+         */
+        unsigned refcnt;
+        
+        /** Number of names this node has in the file system namespace. */
+        unsigned lnkcnt;
+
         link_t nh_link;         /**< Node hash-table link. */
         size_t size;            /**< Cached size of the file. */

uspace/srv/vfs/vfs_lookup.c

@@ -169 +169 @@
                 result->triplet.index = (int) IPC_GET_ARG3(answer);
                 result->size = (size_t) IPC_GET_ARG4(answer);
+                result->lnkcnt = (unsigned) IPC_GET_ARG5(answer);
         }
 

uspace/srv/vfs/vfs_node.c

@@ -149 +149 @@
                 node->index = result->triplet.index;
                 node->size = result->size;
+                node->lnkcnt = result->lnkcnt;
                 link_initialize(&node->nh_link);
                 rwlock_initialize(&node->contents_rwlock);
@@ -157 +158 @@
 
         assert(node->size == result->size);
+        assert(node->lnkcnt == result->lnkcnt);
 
         _vfs_node_addref(node);