On 11/27/2012 12:06 PM, Bryan Schumaker wrote:
> On 11/27/2012 12:01 PM, J. Bruce Fields wrote:
>> On Tue, Nov 27, 2012 at 11:31:11AM -0500, Sasha Levin wrote:
>>> A recent patch series has moved hashtable initialization to when the net
>>> struct is initialized.
>>>
>>> When injecting faults, we tried accessing the hashtables even if the struct
>>> wasn't really initialized (nfsd wasn't in use) - this caused a NULL ptr
>>> deref.
>>
>> Thanks, adding Bryan to cc.--b.
>
> I was just looking over this :). Unfortunately, this patch changes code that
> my most recent patch set removes so my patches will need to change again if
> this goes in first. I'm looking for the best place to put this check to
> avoid having to change each of the forget_something() functions.
>
> - Bryan
This works on top of my most recent patches:
diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c
index 699de07..235162a 100644
--- a/fs/nfsd/fault_inject.c
+++ b/fs/nfsd/fault_inject.c
@@ -76,6 +76,9 @@ static void nfsd_inject_set_client(struct
nfsd_fault_inject_op *op,
u64 count;
struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
nfsd_net_id);
+ if (!nfsd_netns_ready(nn))
+ return;
+
nfs4_lock_state();
clp = nfsd_find_client(nn, addr, addr_size);
if (clp) {
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 227b93e..c5806a57 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -83,5 +83,8 @@ struct nfsd_net {
struct delayed_work laundromat_work;
};
+/* Simple check to find out if a given net was properly initialized */
+#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
+
extern int nfsd_net_id;
#endif /* __NFSD_NETNS_H__ */
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b32414e..84295d9 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4739,6 +4739,9 @@ u64 nfsd_for_n_state(u64 max, u64 (*func)(struct nfsd_net
*, struct nfs4_client
u64 count = 0;
struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
nfsd_net_id);
+ if (!nfsd_netns_ready(nn))
+ return 0;
+
list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) {
count += func(nn, clp, max - count);
if ((max != 0) && (count >= max))
>>
>>>
>>> A simple test would be:
>>>
>>> echo 1 > /sys/kernel/debug/nfsd/forget_locks
>>>
>>> Signed-off-by: Sasha Levin <[email protected]>
>>> ---
>>> fs/nfsd/netns.h | 3 +++
>>> fs/nfsd/nfs4state.c | 9 +++++++++
>>> 2 files changed, 12 insertions(+)
>>>
>>> diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
>>> index 227b93e..c5806a57 100644
>>> --- a/fs/nfsd/netns.h
>>> +++ b/fs/nfsd/netns.h
>>> @@ -83,5 +83,8 @@ struct nfsd_net {
>>> struct delayed_work laundromat_work;
>>> };
>>>
>>> +/* Simple check to find out if a given net was properly initialized */
>>> +#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)
>>> +
>>> extern int nfsd_net_id;
>>> #endif /* __NFSD_NETNS_H__ */
>>> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
>>> index e75872f..0e7428c 100644
>>> --- a/fs/nfsd/nfs4state.c
>>> +++ b/fs/nfsd/nfs4state.c
>>> @@ -4598,6 +4598,9 @@ void nfsd_forget_clients(u64 num)
>>> int count = 0;
>>> struct nfsd_net *nn = net_generic(current->nsproxy->net_ns,
>>> nfsd_net_id);
>>>
>>> + if (!nfsd_netns_ready(nn))
>>> + return;
>>> +
>>> nfs4_lock_state();
>>> list_for_each_entry_safe(clp, next, &nn->client_lru, cl_lru) {
>>> expire_client(clp);
>>> @@ -4643,6 +4646,9 @@ void nfsd_forget_locks(u64 num)
>>> int count;
>>> struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
>>>
>>> + if (!nfsd_netns_ready(nn))
>>> + return;
>>> +
>>> nfs4_lock_state();
>>> count = nfsd_release_n_owners(num, false, release_lockowner_sop, nn);
>>> nfs4_unlock_state();
>>> @@ -4655,6 +4661,9 @@ void nfsd_forget_openowners(u64 num)
>>> int count;
>>> struct nfsd_net *nn = net_generic(&init_net, nfsd_net_id);
>>>
>>> + if (!nfsd_netns_ready(nn))
>>> + return;
>>> +
>>> nfs4_lock_state();
>>> count = nfsd_release_n_owners(num, true, release_openowner_sop, nn);
>>> nfs4_unlock_state();
>>> --
>>> 1.8.0
>>>
>
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