[PATCH nfsd-next] nfsd: fix uninitialised slot info when a request is retried

[PATCH nfsd-next] nfsd: fix uninitialised slot info when a request is retried

[NeilBrown]

A recent patch moved the assignment of seq->maxslots from before the
test for a resent request (which ends with a goto) to after, resulting
in it not being run in that case.  This results in the server returning
bogus "high slot id" and "target high slot id" values.

The assignments to ->maxslots and ->target_maxslots need to be *after*
the out: label so that the correct values are returned in replies to
requests that are served from cache.

Fixes: 60aa6564317d ("nfsd: allocate new session-based DRC slots on demand.")
Signed-off-by: NeilBrown <neilb@suse.de>
---

Feel free to squash this into the offending patch, though subsequent
patches will need to be refreshed carefully.  Or just add it as-is.
Thanks.

 fs/nfsd/nfs4state.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index cc819b8e8acd..b42e2ab7a042 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4460,10 +4460,11 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 			}
 		} while (slot && --cnt > 0);
 	}
+
+out:
 	seq->maxslots = max(session->se_target_maxslots, seq->maxslots);
 	seq->target_maxslots = session->se_target_maxslots;
 
-out:
 	switch (clp->cl_cb_state) {
 	case NFSD4_CB_DOWN:
 		seq->status_flags = SEQ4_STATUS_CB_PATH_DOWN;

base-commit: c1d6e5f7635895b5e9b2e4a9e4b7cdb9cc07eaf7
-- 
2.47.1

Re: [PATCH nfsd-next] nfsd: fix uninitialised slot info when a request is retried

[Jeff Layton]

On Tue, 2025-01-28 at 10:05 +1100, NeilBrown wrote:
> A recent patch moved the assignment of seq->maxslots from before the
> test for a resent request (which ends with a goto) to after, resulting
> in it not being run in that case.  This results in the server returning
> bogus "high slot id" and "target high slot id" values.
> 
> The assignments to ->maxslots and ->target_maxslots need to be *after*
> the out: label so that the correct values are returned in replies to
> requests that are served from cache.
> 
> Fixes: 60aa6564317d ("nfsd: allocate new session-based DRC slots on demand.")
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
> 
> Feel free to squash this into the offending patch, though subsequent
> patches will need to be refreshed carefully.  Or just add it as-is.
> Thanks.
> 
>  fs/nfsd/nfs4state.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index cc819b8e8acd..b42e2ab7a042 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4460,10 +4460,11 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  			}
>  		} while (slot && --cnt > 0);
>  	}
> +
> +out:
>  	seq->maxslots = max(session->se_target_maxslots, seq->maxslots);
>  	seq->target_maxslots = session->se_target_maxslots;
>  
> -out:
>  	switch (clp->cl_cb_state) {
>  	case NFSD4_CB_DOWN:
>  		seq->status_flags = SEQ4_STATUS_CB_PATH_DOWN;
> 
> base-commit: c1d6e5f7635895b5e9b2e4a9e4b7cdb9cc07eaf7

Reviewed-by: Jeff Layton <jlayton@kernel.org>

Re: [PATCH nfsd-next] nfsd: fix uninitialised slot info when a request is retried

[cel]

From: Chuck Lever <chuck.lever@oracle.com>

On Tue, 28 Jan 2025 10:05:03 +1100, NeilBrown wrote:
> A recent patch moved the assignment of seq->maxslots from before the
> test for a resent request (which ends with a goto) to after, resulting
> in it not being run in that case.  This results in the server returning
> bogus "high slot id" and "target high slot id" values.
> 
> The assignments to ->maxslots and ->target_maxslots need to be *after*
> the out: label so that the correct values are returned in replies to
> requests that are served from cache.
> 
> [...]

Applied to nfsd-testing, thanks!

Because I sent the NFSD 6.14 PR yesterday, this fix will be queued
up for 6.14-rc once it has completed a round of testing.

[1/1] nfsd: fix uninitialised slot info when a request is retried
      commit: 78843acb930e16c6f8aa4abd3b82b997c03018c7

--
Chuck Lever