WebSVN – HelenOS – Diff – /branches/network/uspace/srv/fs/tmpfs/tmpfs_ops.c

 #include <errno.h>
 #include <atomic.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
+#include <dirent.h>
 #include <assert.h>
 #include <sys/types.h>
 #include <libadt/hash_table.h>
 #include <as.h>
+}
 /** Compare one component of path to a directory entry.
+ *
  * @param dentry    Directory entry to compare the path component with.
- * @param start     Index into PLB where the path component starts.
+ * @param component Array of characters holding component name.
- * @param last      Index of the last character of the path in PLB.
+ *
- * @return      Zero on failure or delta such that (index + delta) %
+ * @return      True on match, false otherwise.
- *          PLB_SIZE points to the first unprocessed character in
- *          PLB which comprises the path.
  */
-static unsigned match_path_component(tmpfs_dentry_t *dentry, unsigned start,
+static bool match_component(tmpfs_dentry_t *dentry, const char *component)
-    unsigned last)
+{
-    int i, j;
-    size_t namelen;
+    return !strcmp(dentry->name, component);
+}
-    namelen = strlen(dentry->name);
+static unsigned long create_node(tmpfs_dentry_t *dentry,
-    if (last < start)
+    const char *component, int lflag)
+{
-        last += PLB_SIZE;
+    return 0;
+}
-    for (i = 0, j = start; i < namelen && j <= last; i++, j++) {
-        if (dentry->name[i] != PLB_GET_CHAR(j))
+static int destroy_component(tmpfs_dentry_t *dentry)
-            return 0;
-    }
+{
-    if (i != namelen)
-        return 0;
-    if (j < last && PLB_GET_CHAR(j) != '/')
-        return 0;
+    return EPERM;
-    if (j == last)
-            return 0;
-    return (j - start);
+}
 void tmpfs_lookup(ipc_callid_t rid, ipc_call_t *request)
+{
     unsigned next = IPC_GET_ARG1(*request);
     int lflag = IPC_GET_ARG4(*request);
     if (last < next)
         last += PLB_SIZE;
+    /*
+     * Initialize TMPFS.
+     */
     if (!root && !tmpfs_init()) {
         ipc_answer_0(rid, ENOMEM);
         return;
+    }
     tmpfs_dentry_t *dtmp = root->child;
     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) {
+        /* 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 */
-        unsigned delta;
+            if (next <= last)
-        hit = false;
+                continue;
-        do {
+        }
+        assert(len);
+        component[len] = '\0';
+        next++;     /* eat slash */
+        len = 0;
+        /* match the component */
-            delta = match_path_component(dtmp, next, last);
+        while (dtmp && !match_component(dtmp, component))
+            dtmp = dtmp->sibling;
+        /* handle miss: match amongst siblings */
-            if (!delta) {
+        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,
-                dtmp = dtmp->sibling;
+                    component, lflag);
+                if (index) {
+                    ipc_answer_4(rid, EOK,
+                        tmpfs_reg.fs_handle, dev_handle,
+                        index, 0);
-            } else {
+                } else {
+                    ipc_answer_0(rid, ENOSPC);
+                }
-                hit = true;
+                return;
+            }
+            ipc_answer_0(rid, ENOENT);
-                next += delta;
+            return;
+        }
-                next++;     /* eat slash */
+        /* descent one level */
-                dcur = dtmp;
+        dcur = dtmp;
-                dtmp = dtmp->child;
+        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 (delta == 0 && dtmp);
+                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 (!hit) {
+                if (index) {
-            ipc_answer_3(rid, ENOENT, tmpfs_reg.fs_handle,
+                    ipc_answer_4(rid, EOK,
-                dev_handle, dcur->index);
+                        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;
+    }
     ipc_answer_4(rid, EOK, tmpfs_reg.fs_handle, dev_handle, dcur->index,
         dcur->size);
+}

Subversion Repositories HelenOS

(root)/branches/network/uspace/srv/fs/tmpfs/tmpfs_ops.c @ 4718 – Rev 2700 → 2705