From: Trond Myklebust <trond.myklebust@primarydata.com>
To: bfields@fieldses.org
Cc: linux-nfs@vger.kernel.org
Subject: [PATCH v2 7/7] nfsd: Fix races with check_stateid_generation()
Date: Fri, 3 Nov 2017 08:00:16 -0400 [thread overview]
Message-ID: <20171103120016.6200-8-trond.myklebust@primarydata.com> (raw)
In-Reply-To: <20171103120016.6200-7-trond.myklebust@primarydata.com>
The various functions that call check_stateid_generation() in order
to compare a client-supplied stateid with the nfs4_stid state, usually
need to atomically check for closed state. Those that perform the
check after locking the st_mutex using nfsd4_lock_ol_stateid()
should now be OK, but we do want to fix up the others.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
fs/nfsd/nfs4state.c | 22 +++++++++++++++++++---
1 file changed, 19 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index cbd6a10ddda2..6f552ca62415 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -4849,6 +4849,18 @@ static __be32 check_stateid_generation(stateid_t *in, stateid_t *ref, bool has_s
return nfserr_old_stateid;
}
+static __be32 nfsd4_stid_check_stateid_generation(stateid_t *in, struct nfs4_stid *s, bool has_session)
+{
+ __be32 ret;
+
+ spin_lock(&s->sc_lock);
+ ret = nfsd4_verify_open_stid(s);
+ if (ret == nfs_ok)
+ ret = check_stateid_generation(in, &s->sc_stateid, has_session);
+ spin_unlock(&s->sc_lock);
+ return ret;
+}
+
static __be32 nfsd4_check_openowner_confirmed(struct nfs4_ol_stateid *ols)
{
if (ols->st_stateowner->so_is_open_owner &&
@@ -4877,7 +4889,7 @@ static __be32 nfsd4_validate_stateid(struct nfs4_client *cl, stateid_t *stateid)
s = find_stateid_locked(cl, stateid);
if (!s)
goto out_unlock;
- status = check_stateid_generation(stateid, &s->sc_stateid, 1);
+ status = nfsd4_stid_check_stateid_generation(stateid, s, 1);
if (status)
goto out_unlock;
switch (s->sc_type) {
@@ -5022,7 +5034,7 @@ nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
&s, nn);
if (status)
return status;
- status = check_stateid_generation(stateid, &s->sc_stateid,
+ status = nfsd4_stid_check_stateid_generation(stateid, s,
nfsd4_has_session(cstate));
if (status)
goto out;
@@ -5115,6 +5127,7 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
s = find_stateid_locked(cl, stateid);
if (!s)
goto out_unlock;
+ spin_lock(&s->sc_lock);
switch (s->sc_type) {
case NFS4_DELEG_STID:
ret = nfserr_locks_held;
@@ -5126,11 +5139,13 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
ret = nfserr_locks_held;
break;
case NFS4_LOCK_STID:
+ spin_unlock(&s->sc_lock);
atomic_inc(&s->sc_count);
spin_unlock(&cl->cl_lock);
ret = nfsd4_free_lock_stateid(stateid, s);
goto out;
case NFS4_REVOKED_DELEG_STID:
+ spin_unlock(&s->sc_lock);
dp = delegstateid(s);
list_del_init(&dp->dl_recall_lru);
spin_unlock(&cl->cl_lock);
@@ -5139,6 +5154,7 @@ nfsd4_free_stateid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
goto out;
/* Default falls through and returns nfserr_bad_stateid */
}
+ spin_unlock(&s->sc_lock);
out_unlock:
spin_unlock(&cl->cl_lock);
out:
@@ -5418,7 +5434,7 @@ nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
if (status)
goto out;
dp = delegstateid(s);
- status = check_stateid_generation(stateid, &dp->dl_stid.sc_stateid, nfsd4_has_session(cstate));
+ status = nfsd4_stid_check_stateid_generation(stateid, &dp->dl_stid, nfsd4_has_session(cstate));
if (status)
goto put_stateid;
--
2.13.6
next prev parent reply other threads:[~2017-11-03 12:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-03 12:00 [PATCH v2 0/7] Tighten up locking around stateids in knfsd Trond Myklebust
2017-11-03 12:00 ` [PATCH v2 1/7] nfsd: Fix stateid races between OPEN and CLOSE Trond Myklebust
2017-11-03 12:00 ` [PATCH v2 2/7] nfsd: Fix another OPEN stateid race Trond Myklebust
2017-11-03 12:00 ` [PATCH v2 3/7] nfsd: CLOSE SHOULD return the invalid special stateid for NFSv4.x (x>0) Trond Myklebust
2017-11-03 12:00 ` [PATCH v2 4/7] nfsd: Ensure we don't recognise lock stateids after freeing them Trond Myklebust
2017-11-03 12:00 ` [PATCH v2 5/7] nfsd: Fix race in lock stateid creation Trond Myklebust
2017-11-03 12:00 ` [PATCH v2 6/7] nfsd: Ensure we check stateid validity in the seqid operation checks Trond Myklebust
2017-11-03 12:00 ` Trond Myklebust [this message]
2017-11-07 21:37 ` [PATCH v2 5/7] nfsd: Fix race in lock stateid creation J. Bruce Fields
2017-11-07 20:06 ` [PATCH v2 0/7] Tighten up locking around stateids in knfsd J. Bruce Fields
2017-11-07 20:47 ` J. Bruce Fields
2017-11-07 21:55 ` J. Bruce Fields
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