Josef “Jeff” Sipek

So, I was happily browsing around the internet, when I clicked on this one link which opened a new window in firefox. At first, I almost burst out laughing. But by the time, I made the screenshot, I was very annoyed. Here’s the screenshot:

The wording is really crappy. I, as an open source/free software supporter, don’t like this very much. (I am more of an open source than free software person.) It will confuse people that don’t know any better - just like people call GPL/BSD/etc. licensed software "freeware." Grrrr. Can’t you get it? Freeware is the crap you get for Windows. Free software and Open source refer to more than that. Maybe I should send the screenshot to RMS, and let him raise hell :)

I have heard that an unnamed ISP has switched their DNS servers from Bind to something much better — PowerDNS. I, personally, use PowerDNS and I have only positive things to say about it. As for the ISP’s switch, I hear that they reduced they farm of ~190 Bind servers to ~60 PowerDNS servers. Impressive no matter how you look at it! If you are about to set up a DNS server, I suggest you look at PowerDNS.

Think of this as a sequel to my post about a year ago.

The following peice of code is from Unionfs’s copyup_permission(). It is (or should be) a simple function that is supposed to copy the permissions from one inode to another. Well, I can’t help but remember this one slide from Greg Kroah-Hartman’s keynote this year at Ottawa Linux Symposium. Here’s the slide:

The quote definitely applies to copyup_permission(). It seems very clear that it “evolved” to something very odd. Anyway, I shall torment you no longer, here is the code:

static int copyup_permissions(struct super_block *sb,
                              struct dentry *old_hidden_dentry,
                              struct dentry *new_hidden_dentry)
{
        struct iattr newattrs;
        int err;

        print_entry_location();

        newattrs.ia_atime = old_hidden_dentry->d_inode->i_atime;
        newattrs.ia_mtime = old_hidden_dentry->d_inode->i_mtime;
        newattrs.ia_ctime = old_hidden_dentry->d_inode->i_ctime;
        newattrs.ia_valid = ATTR_CTIME | ATTR_ATIME | ATTR_MTIME |
                        ATTR_ATIME_SET | ATTR_MTIME_SET;
        /* original mode of old file */
        newattrs.ia_mode = old_hidden_dentry->d_inode->i_mode;
        newattrs.ia_gid = old_hidden_dentry->d_inode->i_gid;
        newattrs.ia_uid = old_hidden_dentry->d_inode->i_uid;
        newattrs.ia_valid |= ATTR_FORCE | ATTR_GID | ATTR_UID | ATTR_MODE;
        if (newattrs.ia_valid & ATTR_MODE) {
                newattrs.ia_mode = (newattrs.ia_mode & S_IALLUGO) |                
                        (old_hidden_dentry->d_inode->i_mode & ~S_IALLUGO);
        }

        err = notify_change(new_hidden_dentry, &newattrs);

        print_exit_status(err);
        return err;
}

It was actually Seth Arnold that noticed that the condition will ALWAYS be true because ATTR_MODE is set in the line just above it. Furthermore, if one eliminates the if statement and replaces newattr.ia_mode in the assignment with what it is set to just few lines before (right after the comment) he gets:

newattrs.ia_mode = (old_hidden_dentry->d_inode->i_mode & S_IALLUGO) |
                   (old_hidden_dentry->d_inode->i_mode & ~S_IALLUGO);

If you are up to speed with bitwise operations, you’ll realize that it can be simplified to:

newattrs.ia_mode = old_hidden_dentry->d_inode->i_mode;

Brilliant!