NFSv4: Fix a race in NFSv4.1 server trunking discovery

We do not want to allow a race with another NFS mount to cause
nfs41_walk_client_list() to establish a lease on our nfs_client before
we're done checking for trunking.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Trond Myklebust 2015-03-03 20:28:59 -05:00
parent ef070dcb39
commit 48d66b9749
3 changed files with 17 additions and 8 deletions

View file

@ -433,7 +433,7 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat
static bool nfs_client_init_is_complete(const struct nfs_client *clp)
{
return clp->cl_cons_state != NFS_CS_INITING;
return clp->cl_cons_state <= NFS_CS_READY;
}
int nfs_wait_client_init_complete(const struct nfs_client *clp)

View file

@ -621,6 +621,9 @@ int nfs41_walk_client_list(struct nfs_client *new,
spin_lock(&nn->nfs_client_lock);
list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
if (pos == new)
goto found;
if (pos->rpc_ops != new->rpc_ops)
continue;
@ -639,10 +642,6 @@ int nfs41_walk_client_list(struct nfs_client *new,
prev = pos;
status = nfs_wait_client_init_complete(pos);
if (pos->cl_cons_state == NFS_CS_SESSION_INITING) {
nfs4_schedule_lease_recovery(pos);
status = nfs4_wait_clnt_recover(pos);
}
spin_lock(&nn->nfs_client_lock);
if (status < 0)
break;
@ -668,7 +667,7 @@ int nfs41_walk_client_list(struct nfs_client *new,
*/
if (!nfs4_match_client_owner_id(pos, new))
continue;
found:
atomic_inc(&pos->cl_count);
*result = pos;
status = 0;

View file

@ -346,9 +346,19 @@ int nfs41_discover_server_trunking(struct nfs_client *clp,
status = nfs4_proc_exchange_id(clp, cred);
if (status != NFS4_OK)
return status;
set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
return nfs41_walk_client_list(clp, result, cred);
status = nfs41_walk_client_list(clp, result, cred);
if (status < 0)
return status;
if (clp != *result)
return 0;
set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
nfs4_schedule_state_manager(clp);
status = nfs_wait_client_init_complete(clp);
if (status < 0)
nfs_put_client(clp);
return status;
}
#endif /* CONFIG_NFS_V4_1 */