Re: [PATCH] Fix termination state for idr_for_each_entry_ul()

[Paolo Abeni]

On Tue, 2023-10-24 at 09:53 +1100, NeilBrown wrote:
> The comment for idr_for_each_entry_ul() states
> 
>   after normal termination @entry is left with the value NULL
> 
> This is not correct in the case where UINT_MAX has an entry in the idr.
> In that case @entry will be non-NULL after termination.
> No current code depends on the documentation being correct, but to
> save future code we should fix it.
> 
> Also fix idr_for_each_entry_continue_ul().  While this is not documented
> as leaving @entry as NULL, the mellanox driver appears to depend on
> it doing so.  So make that explicit in the documentation as well as in
> the code.
> 
> Fixes: e33d2b74d805 ("idr: fix overflow case for idr_for_each_entry_ul()")
> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
> Cc: Chris Mi <chrism@xxxxxxxxxxxx>
> Cc: Cong Wang <xiyou.wangcong@xxxxxxxxx>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>

Since the affected user is in the netdev tree, I think we can take this
patch. But this is also a sort of gray area of the tree... @Matthew are
you ok with that?

Thanks,

Paolo