Re: [PATCH 0/3] smb/client(cifs): prepare for locking changes.

[Tom Talpey <tom@talpey.com>]

On 10/21/2026 5:55 AM, Christian Brauner wrote:
> On Mon, Sep 28, 2026 at 11:25:01AM +1000, NeilBrown wrote:
>> I am working on changes to directory locking.  The medium term goal is
>> to lift d_alloc_parallel() locking above i_rwsem, so d_alloc_paralle()
>> can be run unlocked, and consequently cannot be called when ->i_rwsem is
>> held.
>>
>> The requires:
>>   1/ that d_alloc_parallel() not be called while i_rwsem is held.  cifs
>>      does this in a couple of places.  A new interface d_alloc_trylock()
>>      is now available and can be used instead.
>>
>>   2/ a dentry must not be d_drop()ed while an operation is ongoing, as an
>>      unlocked d_alloc_parallel() would then be able to create a new
>>      dentry with the same name.  In particular d_rehash() must be phased
>>      out as it won't be safe.  This particularly affects the mechanism to
>>      block lookups/revalidates while an unlink/rename is happening.  The
>>      mechanism is changed to use one similar to how NFS addresses this
>>      needed, though using the new LOOKUP_PRIVATE flag.
>>
>> The patches depend on patches recently added to the vfs tree.  I would
>> prefer these land in that tree too with an Acked-by or similar from cifs
>> maintainers.
> 
> Can do, will need an Ack.
I will defer to Paulo for the Ack, but for the series, modulo my nit
on DCACHE_BLOCKED:

Reviewed-by: Tom Talpey <tom@talpey.com>