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nfsd: Protect adding/removing open state owners using client_lock

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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_open_stateowner checks the hashtable under the
client_lock before adding a new element.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
Trond Myklebust 2014-07-29 21:34:34 -04:00 committed by J. Bruce Fields
parent b401be22b5
commit 7ffb588086
1 changed files with 80 additions and 38 deletions
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118
fs/nfsd/nfs4state.c
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@ -239,6 +239,53 @@ static void nfsd4_put_session(struct nfsd4_session *ses)
spin_unlock(&nn->client_lock);
}
static int
same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner,
clientid_t *clid)
{
return (sop->so_owner.len == owner->len) &&
0 == memcmp(sop->so_owner.data, owner->data, owner->len) &&
(sop->so_client->cl_clientid.cl_id == clid->cl_id);
}
static struct nfs4_openowner *
find_openstateowner_str_locked(unsigned int hashval, struct nfsd4_open *open,
bool sessions, struct nfsd_net *nn)
{
struct nfs4_stateowner *so;
struct nfs4_openowner *oo;
struct nfs4_client *clp;
lockdep_assert_held(&nn->client_lock);
list_for_each_entry(so, &nn->ownerstr_hashtbl[hashval], so_strhash) {
if (!so->so_is_open_owner)
continue;
if (same_owner_str(so, &open->op_owner, &open->op_clientid)) {
oo = openowner(so);
clp = oo->oo_owner.so_client;
if ((bool)clp->cl_minorversion != sessions)
break;
renew_client_locked(clp);
atomic_inc(&so->so_count);
return oo;
}
}
return NULL;
}
static struct nfs4_openowner *
find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
bool sessions, struct nfsd_net *nn)
{
struct nfs4_openowner *oo;
spin_lock(&nn->client_lock);
oo = find_openstateowner_str_locked(hashval, open, sessions, nn);
spin_unlock(&nn->client_lock);
return oo;
}
static inline u32
opaque_hashval(const void *ptr, int nbytes)
@ -1005,8 +1052,13 @@ static void release_open_stateid(struct nfs4_ol_stateid *stp)
nfs4_put_stid(&stp->st_stid);
}
static void unhash_openowner(struct nfs4_openowner *oo)
static void unhash_openowner_locked(struct nfs4_openowner *oo)
{
struct nfsd_net *nn = net_generic(oo->oo_owner.so_client->net,
nfsd_net_id);
lockdep_assert_held(&nn->client_lock);
list_del_init(&oo->oo_owner.so_strhash);
list_del_init(&oo->oo_perclient);
}
@ -1025,18 +1077,29 @@ static void release_last_closed_stateid(struct nfs4_openowner *oo)
static void release_openowner_stateids(struct nfs4_openowner *oo)
{
struct nfs4_ol_stateid *stp;
struct nfsd_net *nn = net_generic(oo->oo_owner.so_client->net,
nfsd_net_id);
lockdep_assert_held(&nn->client_lock);
while (!list_empty(&oo->oo_owner.so_stateids)) {
stp = list_first_entry(&oo->oo_owner.so_stateids,
struct nfs4_ol_stateid, st_perstateowner);
spin_unlock(&nn->client_lock);
release_open_stateid(stp);
spin_lock(&nn->client_lock);
}
}
static void release_openowner(struct nfs4_openowner *oo)
{
unhash_openowner(oo);
struct nfsd_net *nn = net_generic(oo->oo_owner.so_client->net,
nfsd_net_id);
spin_lock(&nn->client_lock);
unhash_openowner_locked(oo);
release_openowner_stateids(oo);
spin_unlock(&nn->client_lock);
release_last_closed_stateid(oo);
nfs4_put_stateowner(&oo->oo_owner);
}
@ -3004,8 +3067,11 @@ static void hash_openowner(struct nfs4_openowner *oo, struct nfs4_client *clp, u
static void nfs4_unhash_openowner(struct nfs4_stateowner *so)
{
struct nfs4_openowner *oo = openowner(so);
struct nfsd_net *nn = net_generic(so->so_client->net, nfsd_net_id);
unhash_openowner(oo);
spin_lock(&nn->client_lock);
unhash_openowner_locked(oo);
spin_unlock(&nn->client_lock);
}
static void nfs4_free_openowner(struct nfs4_stateowner *so)
@ -3025,7 +3091,8 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
struct nfsd4_compound_state *cstate)
{
struct nfs4_client *clp = cstate->clp;
struct nfs4_openowner *oo;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
struct nfs4_openowner *oo, *ret;
oo = alloc_stateowner(openowner_slab, &open->op_owner, clp);
if (!oo)
@ -3039,7 +3106,15 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
oo->oo_time = 0;
oo->oo_last_closed_stid = NULL;
INIT_LIST_HEAD(&oo->oo_close_lru);
hash_openowner(oo, clp, strhashval);
spin_lock(&nn->client_lock);
ret = find_openstateowner_str_locked(strhashval,
open, clp->cl_minorversion, nn);
if (ret == NULL) {
hash_openowner(oo, clp, strhashval);
ret = oo;
} else
nfs4_free_openowner(&oo->oo_owner);
spin_unlock(&nn->client_lock);
return oo;
}
@ -3100,39 +3175,6 @@ move_to_close_lru(struct nfs4_ol_stateid *s, struct net *net)
oo->oo_time = get_seconds();
}
static int
same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner,
clientid_t *clid)
{
return (sop->so_owner.len == owner->len) &&
0 == memcmp(sop->so_owner.data, owner->data, owner->len) &&
(sop->so_client->cl_clientid.cl_id == clid->cl_id);
}
static struct nfs4_openowner *
find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
bool sessions, struct nfsd_net *nn)
{
struct nfs4_stateowner *so;
struct nfs4_openowner *oo;
struct nfs4_client *clp;
list_for_each_entry(so, &nn->ownerstr_hashtbl[hashval], so_strhash) {
if (!so->so_is_open_owner)
continue;
if (same_owner_str(so, &open->op_owner, &open->op_clientid)) {
oo = openowner(so);
clp = oo->oo_owner.so_client;
if ((bool)clp->cl_minorversion != sessions)
return NULL;
renew_client(oo->oo_owner.so_client);
atomic_inc(&oo->oo_owner.so_count);
return oo;
}
}
return NULL;
}
/* search file_hashtbl[] for file */
static struct nfs4_file *
find_file_locked(struct knfsd_fh *fh)