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NFSv4/4.1: Fix bugs in nfs4[01]_walk_client_list

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It is unsafe to use list_for_each_entry_safe() here, because
when we drop the nn->nfs_client_lock, we pin the _current_ list
entry and ensure that it stays in the list, but we don't do the
same for the _next_ list entry. Use of list_for_each_entry() is
therefore the correct thing to do.

Also fix the refcounting in nfs41_walk_client_list().

Finally, ensure that the nfs_client has finished being initialised
and, in the case of NFSv4.1, that the session is set up.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: stable@vger.kernel.org [>= 3.7]
This commit is contained in:
Trond Myklebust 2013-04-05 16:11:11 -04:00
commit 7b1f1fd184
1 changed files with 28 additions and 16 deletions
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44
fs/nfs/nfs4client.c
View file

@ -300,7 +300,7 @@ int nfs40_walk_client_list(struct nfs_client *new,
struct rpc_cred *cred)
{
struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
struct nfs_client *pos, *n, *prev = NULL;
struct nfs_client *pos, *prev = NULL;
struct nfs4_setclientid_res clid = {
.clientid = new->cl_clientid,
.confirm = new->cl_confirm,
@ -308,10 +308,23 @@ int nfs40_walk_client_list(struct nfs_client *new,
int status = -NFS4ERR_STALE_CLIENTID;
spin_lock(&nn->nfs_client_lock);
list_for_each_entry_safe(pos, n, &nn->nfs_client_list, cl_share_link) {
list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
/* If "pos" isn't marked ready, we can't trust the
* remaining fields in "pos" */
if (pos->cl_cons_state < NFS_CS_READY)
if (pos->cl_cons_state > NFS_CS_READY) {
atomic_inc(&pos->cl_count);
spin_unlock(&nn->nfs_client_lock);
if (prev)
nfs_put_client(prev);
prev = pos;
status = nfs_wait_client_init_complete(pos);
spin_lock(&nn->nfs_client_lock);
if (status < 0)
continue;
}
if (pos->cl_cons_state != NFS_CS_READY)
continue;
if (pos->rpc_ops != new->rpc_ops)
@ -423,16 +436,16 @@ int nfs41_walk_client_list(struct nfs_client *new,
struct rpc_cred *cred)
{
struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
struct nfs_client *pos, *n, *prev = NULL;
struct nfs_client *pos, *prev = NULL;
int status = -NFS4ERR_STALE_CLIENTID;
spin_lock(&nn->nfs_client_lock);
list_for_each_entry_safe(pos, n, &nn->nfs_client_list, cl_share_link) {
list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
/* If "pos" isn't marked ready, we can't trust the
* remaining fields in "pos", especially the client
* ID and serverowner fields. Wait for CREATE_SESSION
* to finish. */
if (pos->cl_cons_state < NFS_CS_READY) {
if (pos->cl_cons_state > NFS_CS_READY) {
atomic_inc(&pos->cl_count);
spin_unlock(&nn->nfs_client_lock);
@ -440,18 +453,17 @@ int nfs41_walk_client_list(struct nfs_client *new,
nfs_put_client(prev);
prev = pos;
nfs4_schedule_lease_recovery(pos);
status = nfs_wait_client_init_complete(pos);
if (status < 0) {
nfs_put_client(pos);
spin_lock(&nn->nfs_client_lock);
continue;
if (status == 0) {
nfs4_schedule_lease_recovery(pos);
status = nfs4_wait_clnt_recover(pos);
}
status = pos->cl_cons_state;
spin_lock(&nn->nfs_client_lock);
if (status < 0)
continue;
}
if (pos->cl_cons_state != NFS_CS_READY)
continue;
if (pos->rpc_ops != new->rpc_ops)
continue;
@ -469,17 +481,17 @@ int nfs41_walk_client_list(struct nfs_client *new,
continue;
atomic_inc(&pos->cl_count);
spin_unlock(&nn->nfs_client_lock);
*result = pos;
dprintk("NFS: <-- %s using nfs_client = %p ({%d})\n",
__func__, pos, atomic_read(&pos->cl_count));
*result = pos;
return 0;
break;
}
/* No matching nfs_client found. */
spin_unlock(&nn->nfs_client_lock);
dprintk("NFS: <-- %s status = %d\n", __func__, status);
if (prev)
nfs_put_client(prev);
return status;
}
#endif /* CONFIG_NFS_V4_1 */