Messages in this thread | | | Date | Wed, 11 Jun 2003 02:47:17 +0100 | From | viro@parcelfa ... | Subject | Re: [PATCH] nfs_unlink() race (was: nfs_refresh_inode: inode number mismatch) |
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On Tue, Jun 10, 2003 at 06:28:24PM -0700, Frank Cusack wrote: > On Wed, Jun 11, 2003 at 01:54:25AM +0100, viro@parcelfarce.linux.theplanet.co.uk wrote: > > On Mon, Jun 09, 2003 at 06:51:41AM -0700, Frank Cusack wrote: > > > > > When foo is unlinked, nfs_unlink() does a sillyrename, this puts the > > > dentry on nfs_delete_queue, and (in the VFS) unhashes it from the dcache. > > > This causes a problem, because dentry->d_parent->d_inode is now guaranteed > > > to remain stale. (OK, I'm not really sure about this last part.) > > > > ???? > > > > What does hashed state have to ->d_parent? > > Because now d_parent can be d_deleted (no children) and then go away.
Why? It still has our dentry refering to it and contributing into its ->d_count.
> Then won't dentry->d_parent be wrong? What happens if d_parent becomes > a negative d_entry v. disappearing entirely.
->d_parent will not become negative.
> It is if d_count goes to 0 on one of them and the inode is then unlinked. > But the other dentry remains and again tries to unlink when its d_count > goes to 0. Over NFS the fh includes the generation and so you can't > accidentally delete what only looks like the same file, but what happens > in the local fs?
Please, take a look at the way normal links work.
> Also, the real problem is that something goes wrong with d_parent and
Now, _that_ is interesting. What are you actually seeing there? Note that unhashing doesn't change _any_ ->d_count - hash chains are not counted in it and ->d_parent is not changed.
> NFS tries to refresh an inode that it should really know doesn't exist > anymore. That's why my #2 patch only executes during a rmdir. - 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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