vfs_path_lookup

   1: void lookupInode()

   2: {

   3:     struct dentry* root_dentry;

   4:     struct vfsmount* root_mnt;

   5:     const char* filename;

   6:     struct nameidata data;

   7:     int err = 0;

   8:  

   9:     root_dentry = current->fs->root.dentry;

  10:     root_mnt = current->fs->root.mnt;

  11:     filename = "/mod/case/superblock/tmp";

  12:     //filename = "/boot/vmlinuz-3.0.0-12-generic";

  13:     //filename = "/";

  14:     filename = "/home/danie/filelist.c";

  15:     //filename = "/home/daniel";

  16:     //filename = "/mod/case/superblock/tmp";

  17:     err = vfs_path_lookup(root_dentry,root_mnt,filename,LOOKUP_EXCL,&data);

  18:     printk("lookup %s\n", filename);

  19:     if (err==0)

  20:     {

  21:         struct inode* nodei = data.inode;

  22:         struct address_space* mapping = nodei->i_mapping;

  23:         printk("mapping 0x%08x\n", mapping);

  24:         printk("nr_pages: %d\n", mapping->nrpages);

  25:         

  26:         //printk("Showing:\n");

  27:         printRawData(sizeof(struct inode),nodei);

  28:         

  29:     }

  30:     else

  31:         printk("err: %d\n", err);

  32:  

  33: }

vfs_path_lookup为什么读不到文件，但是能够读到目录？