Changeset b8b23c8 in mainline for uspace/srv/fs/tmpfs/tmpfs_ops.c

Timestamp:

2008-01-26T22:27:34Z (16 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

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

Children:

1fe186f

Parents:

9415601

Message:

More elegant, flexible and complete version of tmpfs_lookup.

File:

• uspace/srv/fs/tmpfs/tmpfs_ops.c (modified) (4 diffs)

uspace/srv/fs/tmpfs/tmpfs_ops.c

@@ -46 +46 @@
 #include <string.h>
 #include <stdio.h>
+#include <dirent.h>
 #include <assert.h>
 #include <sys/types.h>
@@ -199 +200 @@
  *
  * @param dentry        Directory entry to compare the path component with.
- * @param start         Index into PLB where the path component starts.
- * @param last          Index of the last character of the path in PLB.
+ * @param component     Array of characters holding component name.
  *
- * @return              Zero on failure or delta such that (index + delta) %
- *                      PLB_SIZE points to the first unprocessed character in
- *                      PLB which comprises the path.
+ * @return              True on match, false otherwise.
  */
-static unsigned match_path_component(tmpfs_dentry_t *dentry, unsigned start,
-    unsigned last)
-{
-        int i, j;
-        size_t namelen;
-
-        namelen = strlen(dentry->name);
-
-        if (last < start)
-                last += PLB_SIZE;
-
-        for (i = 0, j = start; i < namelen && j <= last; i++, j++) {
-                if (dentry->name[i] != PLB_GET_CHAR(j))
-                        return 0;
-        }
-        
-        if (i != namelen)
-                return 0;
-        if (j < last && PLB_GET_CHAR(j) != '/')
-                return 0;
-        if (j == last)
-                return 0;
-        
-        return (j - start);
+static bool match_component(tmpfs_dentry_t *dentry, const char *component)
+{
+        return !strcmp(dentry->name, component);
+}
+
+static unsigned long create_node(tmpfs_dentry_t *dentry,
+    const char *component, int lflag)
+{
+        return 0;
+}
+
+static int destroy_component(tmpfs_dentry_t *dentry)
+{
+        return EPERM;
 }
 
@@ -242 +230 @@
                 last += PLB_SIZE;
 
+        /*
+         * Initialize TMPFS.
+         */
         if (!root && !tmpfs_init()) {
                 ipc_answer_0(rid, ENOMEM);
@@ -250 +241 @@
         tmpfs_dentry_t *dcur = root;
 
-        bool hit = true;
-        
         if (PLB_GET_CHAR(next) == '/')
                 next++;         /* eat slash */
         
+        char component[NAME_MAX + 1];
+        int len = 0;
         while (next <= last) {
-                unsigned delta;
-                hit = false;
-                do {
-                        delta = match_path_component(dtmp, next, last);
-                        if (!delta) {
-                                dtmp = dtmp->sibling;
-                        } else {
-                                hit = true;
-                                next += delta;
-                                next++;         /* eat slash */
-                                dcur = dtmp;
-                                dtmp = dtmp->child;
-                        }       
-                } while (delta == 0 && dtmp);
-                if (!hit) {
-                        ipc_answer_3(rid, ENOENT, tmpfs_reg.fs_handle,
-                            dev_handle, dcur->index);
+
+                /* collect the component */
+                if (PLB_GET_CHAR(next) != '/') {
+                        if (len + 1 == NAME_MAX) {
+                                /* comopnent length overflow */
+                                ipc_answer_0(rid, ENAMETOOLONG);
+                                return;
+                        }
+                        component[len++] = PLB_GET_CHAR(next);
+                        next++; /* process next character */
+                        if (next <= last)
+                                continue;
+                }
+
+                assert(len);
+                component[len] = '\0';
+                next++;         /* eat slash */
+                len = 0;
+
+                /* match the component */
+                while (dtmp && !match_component(dtmp, component))
+                        dtmp = dtmp->sibling;
+
+                /* handle miss: match amongst siblings */
+                if (!dtmp) {
+                        if ((next > last) && (lflag & L_CREATE)) {
+                                /* no components left and L_CREATE specified */
+                                if (dcur->type != TMPFS_DIRECTORY) {
+                                        ipc_answer_0(rid, ENOTDIR);
+                                        return;
+                                } 
+                                unsigned long index = create_node(dcur,
+                                    component, lflag);
+                                if (index) {
+                                        ipc_answer_4(rid, EOK,
+                                            tmpfs_reg.fs_handle, dev_handle,
+                                            index, 0);
+                                } else {
+                                        ipc_answer_0(rid, ENOSPC);
+                                }
+                                return;
+                        }
+                        ipc_answer_0(rid, ENOENT);
                         return;
                 }
+
+                /* descent one level */
+                dcur = dtmp;
+                dtmp = dtmp->child;
+
+                /* handle miss: excessive components */
+                if (!dtmp && next <= last) {
+                        if (lflag & L_CREATE) {
+                                if (dcur->type != TMPFS_DIRECTORY) {
+                                        ipc_answer_0(rid, ENOTDIR);
+                                        return;
+                                }
+
+                                /* collect next component */
+                                while (next <= last) {
+                                        if (PLB_GET_CHAR(next) == '/') {
+                                                /* more than one component */
+                                                ipc_answer_0(rid, ENOENT);
+                                                return;
+                                        }
+                                        if (len + 1 == NAME_MAX) {
+                                                /* component length overflow */
+                                                ipc_answer_0(rid, ENAMETOOLONG);
+                                                return;
+                                        }
+                                        component[len++] = PLB_GET_CHAR(next);
+                                        next++; /* process next character */
+                                }
+                                assert(len);
+                                component[len] = '\0';
+                                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);
+                                } else {
+                                        ipc_answer_0(rid, ENOSPC);
+                                }
+                                return;
+                        }
+                        ipc_answer_0(rid, ENOENT);
+                        return;
+                }
+        
+        }
+
+        /* handle hit */
+        if (lflag & L_DESTROY) {
+                int res = destroy_component(dcur);
+                ipc_answer_0(rid, res);
+                return;
+        }
+        if ((lflag & (L_CREATE | L_EXCLUSIVE)) == (L_CREATE | L_EXCLUSIVE)) {
+                ipc_answer_0(rid, EEXIST);
+                return;
+        }
+        if ((lflag & L_FILE) && (dcur->type != TMPFS_FILE)) {
+                ipc_answer_0(rid, EISDIR);
+                return;
+        }
+        if ((lflag & L_DIRECTORY) && (dcur->type != TMPFS_DIRECTORY)) {
+                ipc_answer_0(rid, ENOTDIR);
+                return;
         }