Re: [PATCH 02/12] SQUASHME: Bug in new global-device-cache code

[Boaz Harrosh <bharrosh@panasas.com>]

On 05/24/2011 07:52 PM, Benny Halevy wrote:
> On 2011-05-24 18:04, Boaz Harrosh wrote:
>> NULL deref on first ever call. (When device is not found)
>>
>> Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
>> ---
>>  fs/nfs/pnfs_dev.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/fs/nfs/pnfs_dev.c b/fs/nfs/pnfs_dev.c
>> index 7997899..7e5542c 100644
>> --- a/fs/nfs/pnfs_dev.c
>> +++ b/fs/nfs/pnfs_dev.c
>> @@ -100,7 +100,7 @@ _find_get_deviceid(const struct pnfs_layoutdriver_type *ld,
>>  
>>  	rcu_read_lock();
>>  	d = _lookup_deviceid(ld, clp, id, hash);
>> -	if (!atomic_inc_not_zero(&d->ref))
>> +	if (!d || !atomic_inc_not_zero(&d->ref))
> 
> This makes more sense, no?
> +	if (d && !atomic_inc_not_zero(&d->ref))
> 
> Benny
> 
>>  		d = NULL;

Sure, since then d is already set to NULL, I guess

>>  	rcu_read_unlock();
>>  	return d;
> 

Boaz