> On Mon, 2010-08-16 at 15:50 +0800, Bian Naimeng wrote:
>>>>>>>> We should clear NFS_DELEGATED_STATE bit for inode->open_states after return delegation.
... snip ...
>> A open state can be found at nfsi->open_states and owner->so_states always, but
>> it not be found at nfsi->open_files until we call nfs4_intent_set_file.
>>
>> At _nfs4_do_open, we will invoke nfs4_return_incompatible_delegation to return a
>> delegation, a open stateid which set NFS_DELEGATED_STATE bit may not be found at
>> nfsi->open_files, but it still at nfsi->open_states, so we do not clear
>> NFS_DELEGATED_STATE bit for it.
>>
>> Then _nfs4_do_open will find it by nfs4_get_open_state, and we still use it
>> as a delegation, some error will occur.
>>
>
> OK. I see agree that is a race, but AFAICS, your fix means that we end
> up with an nfs_state structure that has cleared NFS_DELEGATED_STATE, but
> that did not recover its open stateid.
>
Hi trond, what do you think about this one?
Best Regards
Bian
-------------------------------------------------------------------------
If there are not any delegation at this inode, we should clear stateid's
NFS_DELEGATED_STATE when update it.
Signed-off-by: Bian Naimeng <biannm@xxxxxxxxxxxxxx>
---
fs/nfs/delegation.c | 1 +
fs/nfs/nfs4proc.c | 12 +++++++++++-
2 files changed, 12 insertions(+), 1 deletions(-)
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index 83bb16f..3a7a19d 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -109,6 +109,7 @@ again:
continue;
if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
continue;
+ clear_bit(NFS_DELEGATED_STATE, &state->flags);
get_nfs_open_context(ctx);
spin_unlock(&inode->i_lock);
err = nfs4_open_delegation_recall(ctx, state, stateid);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 36400d3..c0c0320 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -900,8 +900,18 @@ static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stat
rcu_read_lock();
deleg_cur = rcu_dereference(nfsi->delegation);
- if (deleg_cur == NULL)
+ if (deleg_cur == NULL) {
+ if (delegation == NULL &&
+ test_bit(NFS_DELEGATED_STATE, &state->flags)) {
+ /*FIXME: If the state has NFS_DELEGATED_STATE bit,
+ * we catch a race. Maybe should recover its open
+ * stateid, here we just clear the NFS_DELEGATED_STATE
+ * bit.
+ */
+ clear_bit(NFS_DELEGATED_STATE, &state->flags);
+ }
goto no_delegation;
+ }
spin_lock(&deleg_cur->lock);
if (nfsi->delegation != deleg_cur ||
--
1.6.5.2
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