(fwd) d_path or way to get full pathname

[Marc SCHAEFER]

Hi,

I am trying to find a way to get the full pathname from a dentry
refering a file. I tried d_path(), and in one occasion I got
nothing, and in the other I got rubbish, then the path
I was expecting, and then (deleted).

Also, I am trying to find a way to detect if the buffer
was too small.

Is there a general introduction on dentries somewhere ?
I am persuaded it's going to be useful. Especially for
the locking issues.

This is under 2.2.12.

PS: I *already* (gasp!) found the way to print it
    backwards by following d_parent until it's
    equal to dentry, however a standard function
    would presumably be better.

Here is a code example:

         d_path(dentry, 
                rq->request.path_name,
                sizeof(rq->request.path_name)); /* @@@ res ignored @@@ */
#if 0
         if (some_cond_on_dpath_return_value()) {
            printk("mfs: mfs_com: pathname too long %d at %s.\n",
                         this_length,
                         dentry->d_name.name); /* @@@ really NUL term? @@@ */
            result = MFS_STATUS_OBJECT_NOT_FOUND;
            goto out_abort;
         }
#endif

         printk("mfs_com: complete name: %s.\n",
                rq->request.path_name);

thanks for any idea.