| Message ID | 20170126175628.5794.56813.stgit@manet.1015granger.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Chuck, On 01/26/2017 12:56 PM, Chuck Lever wrote: > Allow RPC-over-RDMA to send NULL pings even when the transport has > hit its credit limit. > > One credit is reserved. It may be used only to send a keepalive > ping. > > Signed-off-by: Chuck Lever <chuck.lever@oracle.com> > --- > include/linux/sunrpc/sched.h | 2 ++ > net/sunrpc/xprt.c | 4 ++++ > net/sunrpc/xprtrdma/transport.c | 4 +++- > net/sunrpc/xprtrdma/verbs.c | 13 ++++++++----- > 4 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h > index 7ba040c..a65278e 100644 > --- a/include/linux/sunrpc/sched.h > +++ b/include/linux/sunrpc/sched.h > @@ -127,6 +127,7 @@ struct rpc_task_setup { > #define RPC_TASK_TIMEOUT 0x1000 /* fail with ETIMEDOUT on timeout */ > #define RPC_TASK_NOCONNECT 0x2000 /* return ENOTCONN if not connected */ > #define RPC_TASK_NO_RETRANS_TIMEOUT 0x4000 /* wait forever for a reply */ > +#define RPC_TASK_PRIORITY 0x8000 /* skip congestion control */ This file also defines various RPC_PRIORITY_<whatever> values that get used for the task->tk_priority field. I wonder if there is a better name for this flag that would help keep people from confusing the two later down the line, but I'm also struggling to come up with anything better. Thoughts? Anna > > #define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC) > #define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER) > @@ -135,6 +136,7 @@ struct rpc_task_setup { > #define RPC_IS_SOFT(t) ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT)) > #define RPC_IS_SOFTCONN(t) ((t)->tk_flags & RPC_TASK_SOFTCONN) > #define RPC_WAS_SENT(t) ((t)->tk_flags & RPC_TASK_SENT) > +#define RPC_HAS_PRIORITY(t) ((t)->tk_flags & RPC_TASK_PRIORITY) > > #define RPC_TASK_RUNNING 0 > #define RPC_TASK_QUEUED 1 > diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c > index b530a28..e8b7b9f 100644 > --- a/net/sunrpc/xprt.c > +++ b/net/sunrpc/xprt.c > @@ -392,6 +392,10 @@ static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *ta > { > struct rpc_rqst *req = task->tk_rqstp; > > + if (RPC_HAS_PRIORITY(task)) { > + req->rq_cong = 0; > + return 1; > + } > if (req->rq_cong) > return 1; > dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", > diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c > index f97c851..e43cc85 100644 > --- a/net/sunrpc/xprtrdma/transport.c > +++ b/net/sunrpc/xprtrdma/transport.c > @@ -538,7 +538,9 @@ static void rpcrdma_keepalive_release(void *calldata) > > data = xprt_get(xprt); > null_task = rpc_call_null_helper(task->tk_client, xprt, NULL, > - RPC_TASK_SOFT | RPC_TASK_ASYNC, > + RPC_TASK_SOFT | > + RPC_TASK_ASYNC | > + RPC_TASK_PRIORITY, > &rpcrdma_keepalive_call_ops, data); > if (!IS_ERR(null_task)) > rpc_put_task(null_task); > diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c > index 7e14b73..3e218dd 100644 > --- a/net/sunrpc/xprtrdma/verbs.c > +++ b/net/sunrpc/xprtrdma/verbs.c > @@ -136,19 +136,20 @@ > static void > rpcrdma_update_granted_credits(struct rpcrdma_rep *rep) > { > - struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf); > struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf; > + __be32 *p = rep->rr_rdmabuf->rg_base; > u32 credits; > > if (rep->rr_len < RPCRDMA_HDRLEN_ERR) > return; > > - credits = be32_to_cpu(rmsgp->rm_credit); > + credits = be32_to_cpup(p + 2); > + if (credits > buffer->rb_max_requests) > + credits = buffer->rb_max_requests; > + /* Reserve one credit for keepalive ping */ > + credits--; > if (credits == 0) > credits = 1; /* don't deadlock */ > - else if (credits > buffer->rb_max_requests) > - credits = buffer->rb_max_requests; > - > atomic_set(&buffer->rb_credits, credits); > } > > @@ -914,6 +915,8 @@ struct rpcrdma_rep * > struct rpcrdma_buffer *buf = &r_xprt->rx_buf; > int i, rc; > > + if (r_xprt->rx_data.max_requests < 2) > + return -EINVAL; > buf->rb_max_requests = r_xprt->rx_data.max_requests; > buf->rb_bc_srv_max_requests = 0; > atomic_set(&buf->rb_credits, 1); > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> On Jan 30, 2017, at 3:29 PM, Anna Schumaker <schumaker.anna@gmail.com> wrote: > > Hi Chuck, > > On 01/26/2017 12:56 PM, Chuck Lever wrote: >> Allow RPC-over-RDMA to send NULL pings even when the transport has >> hit its credit limit. >> >> One credit is reserved. It may be used only to send a keepalive >> ping. >> >> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> >> --- >> include/linux/sunrpc/sched.h | 2 ++ >> net/sunrpc/xprt.c | 4 ++++ >> net/sunrpc/xprtrdma/transport.c | 4 +++- >> net/sunrpc/xprtrdma/verbs.c | 13 ++++++++----- >> 4 files changed, 17 insertions(+), 6 deletions(-) >> >> diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h >> index 7ba040c..a65278e 100644 >> --- a/include/linux/sunrpc/sched.h >> +++ b/include/linux/sunrpc/sched.h >> @@ -127,6 +127,7 @@ struct rpc_task_setup { >> #define RPC_TASK_TIMEOUT 0x1000 /* fail with ETIMEDOUT on timeout */ >> #define RPC_TASK_NOCONNECT 0x2000 /* return ENOTCONN if not connected */ >> #define RPC_TASK_NO_RETRANS_TIMEOUT 0x4000 /* wait forever for a reply */ >> +#define RPC_TASK_PRIORITY 0x8000 /* skip congestion control */ > > This file also defines various RPC_PRIORITY_<whatever> values that get used for the task->tk_priority field. I wonder if there is a better name for this flag that would help keep people from confusing the two later down the line, but I'm also struggling to come up with anything better. PRIORITY was a (lead) trial balloon, and also a sign of weak imagination. The point of the flag is to bypass congestion control. RPC_TASK_SKIPCONG ? Meh. > Thoughts? > Anna > >> >> #define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC) >> #define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER) >> @@ -135,6 +136,7 @@ struct rpc_task_setup { >> #define RPC_IS_SOFT(t) ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT)) >> #define RPC_IS_SOFTCONN(t) ((t)->tk_flags & RPC_TASK_SOFTCONN) >> #define RPC_WAS_SENT(t) ((t)->tk_flags & RPC_TASK_SENT) >> +#define RPC_HAS_PRIORITY(t) ((t)->tk_flags & RPC_TASK_PRIORITY) >> >> #define RPC_TASK_RUNNING 0 >> #define RPC_TASK_QUEUED 1 >> diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c >> index b530a28..e8b7b9f 100644 >> --- a/net/sunrpc/xprt.c >> +++ b/net/sunrpc/xprt.c >> @@ -392,6 +392,10 @@ static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *ta >> { >> struct rpc_rqst *req = task->tk_rqstp; >> >> + if (RPC_HAS_PRIORITY(task)) { >> + req->rq_cong = 0; >> + return 1; >> + } >> if (req->rq_cong) >> return 1; >> dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", >> diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c >> index f97c851..e43cc85 100644 >> --- a/net/sunrpc/xprtrdma/transport.c >> +++ b/net/sunrpc/xprtrdma/transport.c >> @@ -538,7 +538,9 @@ static void rpcrdma_keepalive_release(void *calldata) >> >> data = xprt_get(xprt); >> null_task = rpc_call_null_helper(task->tk_client, xprt, NULL, >> - RPC_TASK_SOFT | RPC_TASK_ASYNC, >> + RPC_TASK_SOFT | >> + RPC_TASK_ASYNC | >> + RPC_TASK_PRIORITY, >> &rpcrdma_keepalive_call_ops, data); >> if (!IS_ERR(null_task)) >> rpc_put_task(null_task); >> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c >> index 7e14b73..3e218dd 100644 >> --- a/net/sunrpc/xprtrdma/verbs.c >> +++ b/net/sunrpc/xprtrdma/verbs.c >> @@ -136,19 +136,20 @@ >> static void >> rpcrdma_update_granted_credits(struct rpcrdma_rep *rep) >> { >> - struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf); >> struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf; >> + __be32 *p = rep->rr_rdmabuf->rg_base; >> u32 credits; >> >> if (rep->rr_len < RPCRDMA_HDRLEN_ERR) >> return; >> >> - credits = be32_to_cpu(rmsgp->rm_credit); >> + credits = be32_to_cpup(p + 2); >> + if (credits > buffer->rb_max_requests) >> + credits = buffer->rb_max_requests; >> + /* Reserve one credit for keepalive ping */ >> + credits--; >> if (credits == 0) >> credits = 1; /* don't deadlock */ >> - else if (credits > buffer->rb_max_requests) >> - credits = buffer->rb_max_requests; >> - >> atomic_set(&buffer->rb_credits, credits); >> } >> >> @@ -914,6 +915,8 @@ struct rpcrdma_rep * >> struct rpcrdma_buffer *buf = &r_xprt->rx_buf; >> int i, rc; >> >> + if (r_xprt->rx_data.max_requests < 2) >> + return -EINVAL; >> buf->rb_max_requests = r_xprt->rx_data.max_requests; >> buf->rb_bc_srv_max_requests = 0; >> atomic_set(&buf->rb_credits, 1); >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Chuck Lever -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 01/30/2017 03:32 PM, Chuck Lever wrote: > >> On Jan 30, 2017, at 3:29 PM, Anna Schumaker <schumaker.anna@gmail.com> wrote: >> >> Hi Chuck, >> >> On 01/26/2017 12:56 PM, Chuck Lever wrote: >>> Allow RPC-over-RDMA to send NULL pings even when the transport has >>> hit its credit limit. >>> >>> One credit is reserved. It may be used only to send a keepalive >>> ping. >>> >>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> >>> --- >>> include/linux/sunrpc/sched.h | 2 ++ >>> net/sunrpc/xprt.c | 4 ++++ >>> net/sunrpc/xprtrdma/transport.c | 4 +++- >>> net/sunrpc/xprtrdma/verbs.c | 13 ++++++++----- >>> 4 files changed, 17 insertions(+), 6 deletions(-) >>> >>> diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h >>> index 7ba040c..a65278e 100644 >>> --- a/include/linux/sunrpc/sched.h >>> +++ b/include/linux/sunrpc/sched.h >>> @@ -127,6 +127,7 @@ struct rpc_task_setup { >>> #define RPC_TASK_TIMEOUT 0x1000 /* fail with ETIMEDOUT on timeout */ >>> #define RPC_TASK_NOCONNECT 0x2000 /* return ENOTCONN if not connected */ >>> #define RPC_TASK_NO_RETRANS_TIMEOUT 0x4000 /* wait forever for a reply */ >>> +#define RPC_TASK_PRIORITY 0x8000 /* skip congestion control */ >> >> This file also defines various RPC_PRIORITY_<whatever> values that get used for the task->tk_priority field. I wonder if there is a better name for this flag that would help keep people from confusing the two later down the line, but I'm also struggling to come up with anything better. > > PRIORITY was a (lead) trial balloon, and also a sign of weak imagination. > > The point of the flag is to bypass congestion control. RPC_TASK_SKIPCONG ? Something like that could work, yeah. Anna > Meh. > > >> Thoughts? >> Anna >> >>> >>> #define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC) >>> #define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER) >>> @@ -135,6 +136,7 @@ struct rpc_task_setup { >>> #define RPC_IS_SOFT(t) ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT)) >>> #define RPC_IS_SOFTCONN(t) ((t)->tk_flags & RPC_TASK_SOFTCONN) >>> #define RPC_WAS_SENT(t) ((t)->tk_flags & RPC_TASK_SENT) >>> +#define RPC_HAS_PRIORITY(t) ((t)->tk_flags & RPC_TASK_PRIORITY) >>> >>> #define RPC_TASK_RUNNING 0 >>> #define RPC_TASK_QUEUED 1 >>> diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c >>> index b530a28..e8b7b9f 100644 >>> --- a/net/sunrpc/xprt.c >>> +++ b/net/sunrpc/xprt.c >>> @@ -392,6 +392,10 @@ static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *ta >>> { >>> struct rpc_rqst *req = task->tk_rqstp; >>> >>> + if (RPC_HAS_PRIORITY(task)) { >>> + req->rq_cong = 0; >>> + return 1; >>> + } >>> if (req->rq_cong) >>> return 1; >>> dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", >>> diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c >>> index f97c851..e43cc85 100644 >>> --- a/net/sunrpc/xprtrdma/transport.c >>> +++ b/net/sunrpc/xprtrdma/transport.c >>> @@ -538,7 +538,9 @@ static void rpcrdma_keepalive_release(void *calldata) >>> >>> data = xprt_get(xprt); >>> null_task = rpc_call_null_helper(task->tk_client, xprt, NULL, >>> - RPC_TASK_SOFT | RPC_TASK_ASYNC, >>> + RPC_TASK_SOFT | >>> + RPC_TASK_ASYNC | >>> + RPC_TASK_PRIORITY, >>> &rpcrdma_keepalive_call_ops, data); >>> if (!IS_ERR(null_task)) >>> rpc_put_task(null_task); >>> diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c >>> index 7e14b73..3e218dd 100644 >>> --- a/net/sunrpc/xprtrdma/verbs.c >>> +++ b/net/sunrpc/xprtrdma/verbs.c >>> @@ -136,19 +136,20 @@ >>> static void >>> rpcrdma_update_granted_credits(struct rpcrdma_rep *rep) >>> { >>> - struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf); >>> struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf; >>> + __be32 *p = rep->rr_rdmabuf->rg_base; >>> u32 credits; >>> >>> if (rep->rr_len < RPCRDMA_HDRLEN_ERR) >>> return; >>> >>> - credits = be32_to_cpu(rmsgp->rm_credit); >>> + credits = be32_to_cpup(p + 2); >>> + if (credits > buffer->rb_max_requests) >>> + credits = buffer->rb_max_requests; >>> + /* Reserve one credit for keepalive ping */ >>> + credits--; >>> if (credits == 0) >>> credits = 1; /* don't deadlock */ >>> - else if (credits > buffer->rb_max_requests) >>> - credits = buffer->rb_max_requests; >>> - >>> atomic_set(&buffer->rb_credits, credits); >>> } >>> >>> @@ -914,6 +915,8 @@ struct rpcrdma_rep * >>> struct rpcrdma_buffer *buf = &r_xprt->rx_buf; >>> int i, rc; >>> >>> + if (r_xprt->rx_data.max_requests < 2) >>> + return -EINVAL; >>> buf->rb_max_requests = r_xprt->rx_data.max_requests; >>> buf->rb_bc_srv_max_requests = 0; >>> atomic_set(&buf->rb_credits, 1); >>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-nfs" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > Chuck Lever > > > -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 7ba040c..a65278e 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -127,6 +127,7 @@ struct rpc_task_setup { #define RPC_TASK_TIMEOUT 0x1000 /* fail with ETIMEDOUT on timeout */ #define RPC_TASK_NOCONNECT 0x2000 /* return ENOTCONN if not connected */ #define RPC_TASK_NO_RETRANS_TIMEOUT 0x4000 /* wait forever for a reply */ +#define RPC_TASK_PRIORITY 0x8000 /* skip congestion control */ #define RPC_IS_ASYNC(t) ((t)->tk_flags & RPC_TASK_ASYNC) #define RPC_IS_SWAPPER(t) ((t)->tk_flags & RPC_TASK_SWAPPER) @@ -135,6 +136,7 @@ struct rpc_task_setup { #define RPC_IS_SOFT(t) ((t)->tk_flags & (RPC_TASK_SOFT|RPC_TASK_TIMEOUT)) #define RPC_IS_SOFTCONN(t) ((t)->tk_flags & RPC_TASK_SOFTCONN) #define RPC_WAS_SENT(t) ((t)->tk_flags & RPC_TASK_SENT) +#define RPC_HAS_PRIORITY(t) ((t)->tk_flags & RPC_TASK_PRIORITY) #define RPC_TASK_RUNNING 0 #define RPC_TASK_QUEUED 1 diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index b530a28..e8b7b9f 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -392,6 +392,10 @@ static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *ta { struct rpc_rqst *req = task->tk_rqstp; + if (RPC_HAS_PRIORITY(task)) { + req->rq_cong = 0; + return 1; + } if (req->rq_cong) return 1; dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c index f97c851..e43cc85 100644 --- a/net/sunrpc/xprtrdma/transport.c +++ b/net/sunrpc/xprtrdma/transport.c @@ -538,7 +538,9 @@ static void rpcrdma_keepalive_release(void *calldata) data = xprt_get(xprt); null_task = rpc_call_null_helper(task->tk_client, xprt, NULL, - RPC_TASK_SOFT | RPC_TASK_ASYNC, + RPC_TASK_SOFT | + RPC_TASK_ASYNC | + RPC_TASK_PRIORITY, &rpcrdma_keepalive_call_ops, data); if (!IS_ERR(null_task)) rpc_put_task(null_task); diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 7e14b73..3e218dd 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -136,19 +136,20 @@ static void rpcrdma_update_granted_credits(struct rpcrdma_rep *rep) { - struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf); struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf; + __be32 *p = rep->rr_rdmabuf->rg_base; u32 credits; if (rep->rr_len < RPCRDMA_HDRLEN_ERR) return; - credits = be32_to_cpu(rmsgp->rm_credit); + credits = be32_to_cpup(p + 2); + if (credits > buffer->rb_max_requests) + credits = buffer->rb_max_requests; + /* Reserve one credit for keepalive ping */ + credits--; if (credits == 0) credits = 1; /* don't deadlock */ - else if (credits > buffer->rb_max_requests) - credits = buffer->rb_max_requests; - atomic_set(&buffer->rb_credits, credits); } @@ -914,6 +915,8 @@ struct rpcrdma_rep * struct rpcrdma_buffer *buf = &r_xprt->rx_buf; int i, rc; + if (r_xprt->rx_data.max_requests < 2) + return -EINVAL; buf->rb_max_requests = r_xprt->rx_data.max_requests; buf->rb_bc_srv_max_requests = 0; atomic_set(&buf->rb_credits, 1);
Allow RPC-over-RDMA to send NULL pings even when the transport has hit its credit limit. One credit is reserved. It may be used only to send a keepalive ping. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- include/linux/sunrpc/sched.h | 2 ++ net/sunrpc/xprt.c | 4 ++++ net/sunrpc/xprtrdma/transport.c | 4 +++- net/sunrpc/xprtrdma/verbs.c | 13 ++++++++----- 4 files changed, 17 insertions(+), 6 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html