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

         ipc_answer_0(rid, EINVAL);
         return;
+    }
     /*
+     * Check whether the file needs to grow.
+     */
+    if (pos + size <= dentry->size) {
+        /* The file size is not changing. */
+        (void) ipc_data_write_deliver(callid, dentry->data + pos, size);
+        ipc_answer_1(rid, EOK, size);
+        return;
+    }
+    size_t delta = (pos + size) - dentry->size;
+    /*
      * At this point, we are deliberately extremely straightforward and
-     * simply realloc the contents of the file on every write. In the end,
+     * simply realloc the contents of the file on every write that grows the
-     * the situation might not be as bad as it may look: our heap allocator
+     * file. In the end, the situation might not be as bad as it may look:
-     * can save us and just grow the block whenever possible.
+     * our heap allocator can save us and just grow the block whenever
+     * possible.
      */
-    void *newdata = realloc(dentry->data, size);
+    void *newdata = realloc(dentry->data, dentry->size + delta);
     if (!newdata) {
         ipc_answer_0(callid, ENOMEM);
         ipc_answer_1(rid, EOK, 0);
         return;
+    }
-    dentry->size = size;
+    dentry->size += delta;
     dentry->data = newdata;
     (void) ipc_data_write_deliver(callid, dentry->data + pos, size);
-    /*
-     * Answer the VFS_WRITE call.
-     */
     ipc_answer_1(rid, EOK, size);
+}
 /**
  * @}

Subversion Repositories HelenOS

(root)//trunk/uspace/srv/fs/tmpfs/tmpfs_ops.c – Rev 2666 → 2667