Messages in this thread | | | Date | Tue, 11 Jan 2011 23:57:22 +1100 | Subject | Re: Important for fs devs: rcu-walk merged upstream | From | Nick Piggin <> |
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On Tuesday, January 11, 2011, J. R. Okajima <hooanon05@yahoo.co.jp> wrote: > > Nick Piggin: >> This is a big and complex change by any measure, so >> please don't be afraid to ask for help or clarification. I'd >> also really like to be able to update documentation >> based on questions from fs maintainers (in and out of >> tree) who are trying to follow it and bring their code up to >> speed. > > Question about what d_lock protects. > Can we skip d_lock when we access d_inode and d_name during its parent > i_mutex is held?
That is a good observation. I think we are ok here because parent mutex should stabilize children names and linkages.
But the documentation for a lot of locking is not complete. It would be nice to improve.
> Should these BUG_ON be placed after d_lock? > > void dentry_update_name_case(struct dentry *dentry, struct qstr *name) > { > BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex)); > BUG_ON(dentry->d_name.len != name->len); /* d_lookup gives this */ > > spin_lock(&dentry->d_lock); > ::: > > > J. R. Okajima > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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