nfs: enforce FIFO ordering of operations trying to acquire slot

Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Alexandros Batsakis 2009-12-14 21:27:56 -08:00 committed by Trond Myklebust
parent cf3b01b548
commit 689cf5c15b
3 changed files with 35 additions and 6 deletions

View file

@ -346,8 +346,12 @@ nfs4_free_slot(struct nfs4_slot_table *tbl, u8 free_slotid)
*/
static void nfs41_check_drain_session_complete(struct nfs4_session *ses)
{
struct rpc_task *task;
if (!test_bit(NFS4CLNT_SESSION_DRAINING, &ses->clp->cl_state)) {
rpc_wake_up_next(&ses->fc_slot_table.slot_tbl_waitq);
task = rpc_wake_up_next(&ses->fc_slot_table.slot_tbl_waitq);
if (task)
rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
return;
}
@ -483,6 +487,14 @@ static int nfs41_setup_sequence(struct nfs4_session *session,
return -EAGAIN;
}
if (!rpc_queue_empty(&tbl->slot_tbl_waitq) &&
!rpc_task_has_priority(task, RPC_PRIORITY_PRIVILEGED)) {
rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL);
spin_unlock(&tbl->slot_tbl_lock);
dprintk("%s enforce FIFO order\n", __func__);
return -EAGAIN;
}
slotid = nfs4_find_slot(tbl);
if (slotid == NFS4_MAX_SLOT_TABLE) {
rpc_sleep_on(&tbl->slot_tbl_waitq, task, NULL);
@ -492,6 +504,7 @@ static int nfs41_setup_sequence(struct nfs4_session *session,
}
spin_unlock(&tbl->slot_tbl_lock);
rpc_task_set_priority(task, RPC_PRIORITY_NORMAL);
slot = tbl->slots + slotid;
args->sa_session = session;
args->sa_slotid = slotid;
@ -4401,11 +4414,12 @@ static void nfs4_get_lease_time_prepare(struct rpc_task *task,
(struct nfs4_get_lease_time_data *)calldata;
dprintk("--> %s\n", __func__);
rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
/* just setup sequence, do not trigger session recovery
since we're invoked within one */
ret = nfs41_setup_sequence(data->clp->cl_session,
&data->args->la_seq_args,
&data->res->lr_seq_res, 0, task);
&data->args->la_seq_args,
&data->res->lr_seq_res, 0, task);
BUG_ON(ret == -EAGAIN);
rpc_call_start(task);
@ -4625,7 +4639,7 @@ struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp)
tbl = &session->fc_slot_table;
tbl->highest_used_slotid = -1;
spin_lock_init(&tbl->slot_tbl_lock);
rpc_init_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table");
rpc_init_priority_wait_queue(&tbl->slot_tbl_waitq, "ForeChannel Slot table");
tbl = &session->bc_slot_table;
tbl->highest_used_slotid = -1;

View file

@ -138,8 +138,22 @@ static int nfs41_setup_state_renewal(struct nfs_client *clp)
static void nfs41_end_drain_session(struct nfs_client *clp,
struct nfs4_session *ses)
{
if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state))
rpc_wake_up(&ses->fc_slot_table.slot_tbl_waitq);
int max_slots;
if (test_and_clear_bit(NFS4CLNT_SESSION_DRAINING, &clp->cl_state)) {
spin_lock(&ses->fc_slot_table.slot_tbl_lock);
max_slots = ses->fc_slot_table.max_slots;
while (max_slots--) {
struct rpc_task *task;
task = rpc_wake_up_next(&ses->fc_slot_table.
slot_tbl_waitq);
if (!task)
break;
rpc_task_set_priority(task, RPC_PRIORITY_PRIVILEGED);
}
spin_unlock(&ses->fc_slot_table.slot_tbl_lock);
}
}
static int nfs41_begin_drain_session(struct nfs_client *clp,

View file

@ -210,6 +210,7 @@ void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qnam
{
__rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY);
}
EXPORT_SYMBOL_GPL(rpc_init_priority_wait_queue);
void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
{