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@xxxxxxxxxx>
Cc: Chuck Lever <chuck.lever@xxxxxxxxxx>
Cc: Bryan Schumaker <bjschuma@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx [>= 3.7]
---
fs/nfs/nfs4client.c | 44 ++++++++++++++++++++++++++++----------------
1 file changed, 28 insertions(+), 16 deletions(-)
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index ac4fc9a..c7b346f 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -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 */
--
1.8.1.4
--
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