On Fri, Aug 19, 2011 at 01:09:36PM -0400, Trond Myklebust wrote:
> > void locks_remove_posix(struct file *filp, fl_owner_t owner)
> > {
> > struct file_lock lock;
> > + struct file_lock **before;
> > + struct inode *inode;
> >
> > /*
> > * If there are no locks held on this file, we don't need to call
> > * posix_lock_file(). Another process could be setting a lock on this
> > * file at the same time, but we wouldn't remove that lock anyway.
> > */
> > - if (!filp->f_path.dentry->d_inode->i_flock)
> > + inode = filp->f_path.dentry->d_inode;
> > +
> > + if (!inode->i_flock)
> > return;
> >
> > + lock_flocks();
> > + for_each_lock(inode, before) {
> > + struct file_lock *fl = *before;
> > + if (IS_POSIX(fl))
> > + goto do_unlock;
> > + }
> > + unlock_flocks();
> > + return;
> > +
> > +do_unlock:
> > + unlock_flocks();
> > lock.fl_type = F_UNLCK;
> > lock.fl_flags = FL_POSIX | FL_CLOSE;
> > lock.fl_start = 0;
>
> This assumes that all locks are mirrored in inode->i_flock, which may
> not be the case if the filesystem implements its own f_op->lock(). The
> right place for this optimisation would be in your filesystem callback.
I suppose if i_flock is being faked at the same time to avoid the null
check. I once looked at not doing lock mirroring in vfs and couldn't for
reasons I don't remember... may the null i_flock check was the only
reason, not sure.
Dave
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
