From 689cf5c15baf603a8041565ff0bd0d65d1634fd7 Mon Sep 17 00:00:00 2001 From: Alexandros Batsakis Date: Mon, 14 Dec 2009 21:27:56 -0800 Subject: [PATCH] nfs: enforce FIFO ordering of operations trying to acquire slot Signed-off-by: Alexandros Batsakis Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 22 ++++++++++++++++++---- fs/nfs/nfs4state.c | 18 ++++++++++++++++-- net/sunrpc/sched.c | 1 + 3 files changed, 35 insertions(+), 6 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index acd698baf8eb..02513da9a016 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -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; diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index e76427e6346f..0e45075836b2 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -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, diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c index 89ea8e69ec78..aae6907fd546 100644 --- a/net/sunrpc/sched.c +++ b/net/sunrpc/sched.c @@ -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) {