From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Once we remove client mutex protection, we'll need to ensure that
stateowner lookup and creation are atomic between concurrent compounds.
Ensure that alloc_init_lock_stateowner checks the hashtable under the
client_lock before adding a new element.
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 61 insertions(+), 8 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 743a48b6e84a..18ab6550d65d 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -964,26 +964,42 @@ static void release_lock_stateid(struct nfs4_ol_stateid *stp)
put_generic_stateid(stp);
}
-static void unhash_lockowner(struct nfs4_lockowner *lo)
+static void unhash_lockowner_locked(struct nfs4_lockowner *lo)
{
+ struct nfsd_net *nn = net_generic(lo->lo_owner.so_client->net,
+ nfsd_net_id);
+
+ lockdep_assert_held(&nn->client_lock);
+
list_del_init(&lo->lo_owner.so_strhash);
}
static void release_lockowner_stateids(struct nfs4_lockowner *lo)
{
+ struct nfsd_net *nn = net_generic(lo->lo_owner.so_client->net,
+ nfsd_net_id);
struct nfs4_ol_stateid *stp;
+ lockdep_assert_held(&nn->client_lock);
+
while (!list_empty(&lo->lo_owner.so_stateids)) {
stp = list_first_entry(&lo->lo_owner.so_stateids,
struct nfs4_ol_stateid, st_perstateowner);
+ spin_unlock(&nn->client_lock);
release_lock_stateid(stp);
+ spin_lock(&nn->client_lock);
}
}
static void release_lockowner(struct nfs4_lockowner *lo)
{
- unhash_lockowner(lo);
+ struct nfsd_net *nn = net_generic(lo->lo_owner.so_client->net,
+ nfsd_net_id);
+
+ spin_lock(&nn->client_lock);
+ unhash_lockowner_locked(lo);
release_lockowner_stateids(lo);
+ spin_unlock(&nn->client_lock);
nfs4_put_stateowner(&lo->lo_owner);
}
@@ -4795,7 +4811,7 @@ nevermind:
}
static struct nfs4_lockowner *
-find_lockowner_str(clientid_t *clid, struct xdr_netobj *owner,
+find_lockowner_str_locked(clientid_t *clid, struct xdr_netobj *owner,
struct nfsd_net *nn)
{
unsigned int strhashval = ownerstr_hashval(clid->cl_id, owner);
@@ -4812,9 +4828,25 @@ find_lockowner_str(clientid_t *clid, struct xdr_netobj *owner,
return NULL;
}
+static struct nfs4_lockowner *
+find_lockowner_str(clientid_t *clid, struct xdr_netobj *owner,
+ struct nfsd_net *nn)
+{
+ struct nfs4_lockowner *lo;
+
+ spin_lock(&nn->client_lock);
+ lo = find_lockowner_str_locked(clid, owner, nn);
+ spin_unlock(&nn->client_lock);
+ return lo;
+}
+
static void nfs4_unhash_lockowner(struct nfs4_stateowner *sop)
{
- unhash_lockowner(lockowner(sop));
+ struct nfsd_net *nn = net_generic(sop->so_client->net, nfsd_net_id);
+
+ spin_lock(&nn->client_lock);
+ unhash_lockowner_locked(lockowner(sop));
+ spin_unlock(&nn->client_lock);
}
static void nfs4_free_lockowner(struct nfs4_stateowner *sop)
@@ -4833,9 +4865,12 @@ static void nfs4_free_lockowner(struct nfs4_stateowner *sop)
* strhashval = ownerstr_hashval
*/
static struct nfs4_lockowner *
-alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, struct nfs4_ol_stateid *open_stp, struct nfsd4_lock *lock) {
- struct nfs4_lockowner *lo;
+alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp,
+ struct nfs4_ol_stateid *open_stp,
+ struct nfsd4_lock *lock)
+{
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
+ struct nfs4_lockowner *lo, *ret;
lo = alloc_stateowner(lockowner_slab, &lock->lk_new_owner, clp);
if (!lo)
@@ -4845,7 +4880,16 @@ alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, str
lo->lo_owner.so_seqid = lock->lk_new_lock_seqid;
lo->lo_owner.so_free = nfs4_free_lockowner;
lo->lo_owner.so_unhash = nfs4_unhash_lockowner;
- list_add(&lo->lo_owner.so_strhash, &nn->ownerstr_hashtbl[strhashval]);
+ spin_lock(&nn->client_lock);
+ ret = find_lockowner_str_locked(&clp->cl_clientid,
+ &lock->lk_new_owner, nn);
+ if (ret == NULL) {
+ list_add(&lo->lo_owner.so_strhash,
+ &nn->ownerstr_hashtbl[strhashval]);
+ ret = lo;
+ } else
+ nfs4_free_lockowner(&lo->lo_owner);
+ spin_unlock(&nn->client_lock);
return lo;
}
@@ -5373,6 +5417,7 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
unsigned int hashval = ownerstr_hashval(clid->cl_id, owner);
__be32 status;
struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+ struct nfs4_client *clp;
dprintk("nfsd4_release_lockowner clientid: (%08x/%08x):\n",
clid->cl_boot, clid->cl_id);
@@ -5386,6 +5431,7 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
status = nfserr_locks_held;
/* Find the matching lock stateowner */
+ spin_lock(&nn->client_lock);
list_for_each_entry(tmp, &nn->ownerstr_hashtbl[hashval], so_strhash) {
if (tmp->so_is_open_owner)
continue;
@@ -5395,6 +5441,7 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
break;
}
}
+ spin_unlock(&nn->client_lock);
/* No matching owner found, maybe a replay? Just declare victory... */
if (!sop) {
@@ -5404,16 +5451,22 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp,
lo = lockowner(sop);
/* see if there are still any locks associated with it */
+ clp = cstate->clp;
+ spin_lock(&clp->cl_lock);
list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) {
if (check_for_locks(stp->st_stid.sc_file, lo)) {
- nfs4_put_stateowner(sop);
+ spin_unlock(&clp->cl_lock);
goto out;
}
}
+ spin_unlock(&clp->cl_lock);
status = nfs_ok;
+ sop = NULL;
release_lockowner(lo);
out:
+ if (sop)
+ nfs4_put_stateowner(sop);
nfs4_unlock_state();
return status;
}
--
1.9.3
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