On Tue, 2012-02-14 at 19:53 -0500, J. Bruce Fields wrote:
> On Wed, Feb 15, 2012 at 12:43:08AM +0000, Myklebust, Trond wrote:
> > Then we have a problem. The zero initialisation is already in use out
> > there in both commercial and non-commercial versions of Linux. It is too
> > late to change that now.
> >
> > Furthermore, since none of the servers we've tested against in earlier
> > Bakeathons and Connectathons have complained, I suggest that we rather
> > change the spec with an errata.
>
> Argh.
>
> I just noticed that the server was crashing intermittently and traced it
> to incorrect handling of the case where the client sends a one-op
> SEQUENCE compound with seqid 0. I'm not sure why it started popping up
> just in 3.3--perhaps some change in the way the client uses slots made
> that more likely.
>
> The server code actually looks like it did assume initial seqid 1, but
> accepted initial seqid 0 (except in this one case) basically by mistake.
>
> In any case, I think it should be easy enough to teach it just to accept
> any seqid on a previously unused slot, so I'll do that....
Hang on... Looking at 3.2, I think you're correct. We used to initialise
to 1, and now we're initialising to 0.
Ah... I see what happened.
commit aacd5537270a752fe12a9914a207284fc2341c6d (NFSv4.1: cleanup init
and reset of session slot tables) seems to have removed the call to
nfs4_reset_slot_tables() that was doing that initialisation. OK... So
this is a Linux 3.3-rcX only regression, and should be treated as
such...
How about the following instead so that we ensure we fully share the
initialisation code between nfs4_reset_slot_tables and
nfs4_init_slot_tables?
8<-------------------------------------------------------------------------
>From 8ae8d177cc106ecdb3e29b48c78ec37cf76ea549 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Date: Tue, 14 Feb 2012 20:33:19 -0500
Subject: [PATCH] NFSv4.1: Fix a NFSv4.1 session initialisation regression
Commit aacd553 (NFSv4.1: cleanup init and reset of session slot tables)
introduces a regression in the session initialisation code. New tables
now find their sequence ids initialised to 0, rather than the mandated
value of 1 (see RFC5661).
Reported-by: Vitaliy Gusev <gusev.vitaliy@xxxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
fs/nfs/nfs4proc.c | 58 ++++++++++++++++++++++++++++++++---------------------
1 files changed, 35 insertions(+), 23 deletions(-)
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d202e04..9f76ce9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5008,37 +5008,53 @@ int nfs4_proc_get_lease_time(struct nfs_client *clp, struct nfs_fsinfo *fsinfo)
return status;
}
+static struct nfs4_slot *nfs4_session_alloc_slots(u32 max_slots, gfp_t gfp_flags)
+{
+ return kcalloc(max_slots, sizeof(struct nfs4_slot), gfp_flags);
+}
+
+static void nfs4_session_add_slots(struct nfs4_slot_table *tbl,
+ struct nfs4_slot *new,
+ u32 max_slots,
+ u32 ivalue)
+{
+ struct nfs4_slot *old = NULL;
+ u32 i;
+
+ spin_lock(&tbl->slot_tbl_lock);
+ if (new) {
+ old = tbl->slots;
+ tbl->slots = new;
+ tbl->max_slots = max_slots;
+ }
+ tbl->highest_used_slotid = -1; /* no slot is currently used */
+ for (i = 0; i < tbl->max_slots; i++)
+ tbl->slots[i].seq_nr = ivalue;
+ spin_unlock(&tbl->slot_tbl_lock);
+ kfree(old);
+}
+
/*
* Reset a slot table
*/
static int nfs4_reset_slot_table(struct nfs4_slot_table *tbl, u32 max_reqs,
- int ivalue)
+ u32 ivalue)
{
struct nfs4_slot *new = NULL;
- int i;
- int ret = 0;
+ int ret = -ENOMEM;
dprintk("--> %s: max_reqs=%u, tbl->max_slots %d\n", __func__,
max_reqs, tbl->max_slots);
/* Does the newly negotiated max_reqs match the existing slot table? */
if (max_reqs != tbl->max_slots) {
- ret = -ENOMEM;
- new = kmalloc(max_reqs * sizeof(struct nfs4_slot),
- GFP_NOFS);
+ new = nfs4_session_alloc_slots(max_reqs, GFP_NOFS);
if (!new)
goto out;
- ret = 0;
- kfree(tbl->slots);
}
- spin_lock(&tbl->slot_tbl_lock);
- if (new) {
- tbl->slots = new;
- tbl->max_slots = max_reqs;
- }
- for (i = 0; i < tbl->max_slots; ++i)
- tbl->slots[i].seq_nr = ivalue;
- spin_unlock(&tbl->slot_tbl_lock);
+ ret = 0;
+
+ nfs4_session_add_slots(tbl, new, max_reqs, ivalue);
dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__,
tbl, tbl->slots, tbl->max_slots);
out:
@@ -5064,7 +5080,7 @@ static void nfs4_destroy_slot_tables(struct nfs4_session *session)
* Initialize slot table
*/
static int nfs4_init_slot_table(struct nfs4_slot_table *tbl,
- int max_slots, int ivalue)
+ u32 max_slots, u32 ivalue)
{
struct nfs4_slot *slot;
int ret = -ENOMEM;
@@ -5073,16 +5089,12 @@ static int nfs4_init_slot_table(struct nfs4_slot_table *tbl,
dprintk("--> %s: max_reqs=%u\n", __func__, max_slots);
- slot = kcalloc(max_slots, sizeof(struct nfs4_slot), GFP_NOFS);
+ slot = nfs4_session_alloc_slots(max_slots, GFP_NOFS);
if (!slot)
goto out;
ret = 0;
- spin_lock(&tbl->slot_tbl_lock);
- tbl->max_slots = max_slots;
- tbl->slots = slot;
- tbl->highest_used_slotid = -1; /* no slot is currently used */
- spin_unlock(&tbl->slot_tbl_lock);
+ nfs4_session_add_slots(tbl, slot, max_slots, ivalue);
dprintk("%s: tbl=%p slots=%p max_slots=%d\n", __func__,
tbl, tbl->slots, tbl->max_slots);
out:
--
1.7.7.6
--
Trond Myklebust
Linux NFS client maintainer
NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com
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