[question] why does pipefs bother to build unique filenames?

[Tigran Aivazian]

Hi guys,

In fs/pipe.c:do_pipe() we see this code:

        sprintf(name, "%lu", inode->i_ino);
        this.name = name;
        this.len = strlen(name);
        /* We don't care for hash - it will never be looked up */
        dentry = d_alloc(pipe_mnt->mnt_sb->s_root, &this);

why do we bother building unique dentry name if it is never going to be
looked up anyway? Couldn't we just set this.len = 0 or is it invalid for
dentry cache to have 0-length entries? If so, ok we can make it non-0
length but does it have to be unique given that it is never looked
up? Then we could at least get rid of sprintf() overhead.

Regards,
Tigran