![J. Bruce Fields](/assets/img/avatar_default.png)
We saw a report of a NULL dereference in xprt_autoclose: https://bugzilla.redhat.com/show_bug.cgi?id=611938 This appears to be the result of an xprt's task_cleanup running after the xprt is destroyed. Nothing in the current code appears to prevent that. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
1161 lines
30 KiB
C
1161 lines
30 KiB
C
/*
|
|
* linux/net/sunrpc/xprt.c
|
|
*
|
|
* This is a generic RPC call interface supporting congestion avoidance,
|
|
* and asynchronous calls.
|
|
*
|
|
* The interface works like this:
|
|
*
|
|
* - When a process places a call, it allocates a request slot if
|
|
* one is available. Otherwise, it sleeps on the backlog queue
|
|
* (xprt_reserve).
|
|
* - Next, the caller puts together the RPC message, stuffs it into
|
|
* the request struct, and calls xprt_transmit().
|
|
* - xprt_transmit sends the message and installs the caller on the
|
|
* transport's wait list. At the same time, if a reply is expected,
|
|
* it installs a timer that is run after the packet's timeout has
|
|
* expired.
|
|
* - When a packet arrives, the data_ready handler walks the list of
|
|
* pending requests for that transport. If a matching XID is found, the
|
|
* caller is woken up, and the timer removed.
|
|
* - When no reply arrives within the timeout interval, the timer is
|
|
* fired by the kernel and runs xprt_timer(). It either adjusts the
|
|
* timeout values (minor timeout) or wakes up the caller with a status
|
|
* of -ETIMEDOUT.
|
|
* - When the caller receives a notification from RPC that a reply arrived,
|
|
* it should release the RPC slot, and process the reply.
|
|
* If the call timed out, it may choose to retry the operation by
|
|
* adjusting the initial timeout value, and simply calling rpc_call
|
|
* again.
|
|
*
|
|
* Support for async RPC is done through a set of RPC-specific scheduling
|
|
* primitives that `transparently' work for processes as well as async
|
|
* tasks that rely on callbacks.
|
|
*
|
|
* Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
|
|
*
|
|
* Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/workqueue.h>
|
|
#include <linux/net.h>
|
|
#include <linux/ktime.h>
|
|
|
|
#include <linux/sunrpc/clnt.h>
|
|
#include <linux/sunrpc/metrics.h>
|
|
#include <linux/sunrpc/bc_xprt.h>
|
|
|
|
#include "sunrpc.h"
|
|
|
|
/*
|
|
* Local variables
|
|
*/
|
|
|
|
#ifdef RPC_DEBUG
|
|
# define RPCDBG_FACILITY RPCDBG_XPRT
|
|
#endif
|
|
|
|
/*
|
|
* Local functions
|
|
*/
|
|
static void xprt_request_init(struct rpc_task *, struct rpc_xprt *);
|
|
static void xprt_connect_status(struct rpc_task *task);
|
|
static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
|
|
|
|
static DEFINE_SPINLOCK(xprt_list_lock);
|
|
static LIST_HEAD(xprt_list);
|
|
|
|
/*
|
|
* The transport code maintains an estimate on the maximum number of out-
|
|
* standing RPC requests, using a smoothed version of the congestion
|
|
* avoidance implemented in 44BSD. This is basically the Van Jacobson
|
|
* congestion algorithm: If a retransmit occurs, the congestion window is
|
|
* halved; otherwise, it is incremented by 1/cwnd when
|
|
*
|
|
* - a reply is received and
|
|
* - a full number of requests are outstanding and
|
|
* - the congestion window hasn't been updated recently.
|
|
*/
|
|
#define RPC_CWNDSHIFT (8U)
|
|
#define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
|
|
#define RPC_INITCWND RPC_CWNDSCALE
|
|
#define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
|
|
|
|
#define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
|
|
|
|
/**
|
|
* xprt_register_transport - register a transport implementation
|
|
* @transport: transport to register
|
|
*
|
|
* If a transport implementation is loaded as a kernel module, it can
|
|
* call this interface to make itself known to the RPC client.
|
|
*
|
|
* Returns:
|
|
* 0: transport successfully registered
|
|
* -EEXIST: transport already registered
|
|
* -EINVAL: transport module being unloaded
|
|
*/
|
|
int xprt_register_transport(struct xprt_class *transport)
|
|
{
|
|
struct xprt_class *t;
|
|
int result;
|
|
|
|
result = -EEXIST;
|
|
spin_lock(&xprt_list_lock);
|
|
list_for_each_entry(t, &xprt_list, list) {
|
|
/* don't register the same transport class twice */
|
|
if (t->ident == transport->ident)
|
|
goto out;
|
|
}
|
|
|
|
list_add_tail(&transport->list, &xprt_list);
|
|
printk(KERN_INFO "RPC: Registered %s transport module.\n",
|
|
transport->name);
|
|
result = 0;
|
|
|
|
out:
|
|
spin_unlock(&xprt_list_lock);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_register_transport);
|
|
|
|
/**
|
|
* xprt_unregister_transport - unregister a transport implementation
|
|
* @transport: transport to unregister
|
|
*
|
|
* Returns:
|
|
* 0: transport successfully unregistered
|
|
* -ENOENT: transport never registered
|
|
*/
|
|
int xprt_unregister_transport(struct xprt_class *transport)
|
|
{
|
|
struct xprt_class *t;
|
|
int result;
|
|
|
|
result = 0;
|
|
spin_lock(&xprt_list_lock);
|
|
list_for_each_entry(t, &xprt_list, list) {
|
|
if (t == transport) {
|
|
printk(KERN_INFO
|
|
"RPC: Unregistered %s transport module.\n",
|
|
transport->name);
|
|
list_del_init(&transport->list);
|
|
goto out;
|
|
}
|
|
}
|
|
result = -ENOENT;
|
|
|
|
out:
|
|
spin_unlock(&xprt_list_lock);
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_unregister_transport);
|
|
|
|
/**
|
|
* xprt_load_transport - load a transport implementation
|
|
* @transport_name: transport to load
|
|
*
|
|
* Returns:
|
|
* 0: transport successfully loaded
|
|
* -ENOENT: transport module not available
|
|
*/
|
|
int xprt_load_transport(const char *transport_name)
|
|
{
|
|
struct xprt_class *t;
|
|
int result;
|
|
|
|
result = 0;
|
|
spin_lock(&xprt_list_lock);
|
|
list_for_each_entry(t, &xprt_list, list) {
|
|
if (strcmp(t->name, transport_name) == 0) {
|
|
spin_unlock(&xprt_list_lock);
|
|
goto out;
|
|
}
|
|
}
|
|
spin_unlock(&xprt_list_lock);
|
|
result = request_module("xprt%s", transport_name);
|
|
out:
|
|
return result;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_load_transport);
|
|
|
|
/**
|
|
* xprt_reserve_xprt - serialize write access to transports
|
|
* @task: task that is requesting access to the transport
|
|
*
|
|
* This prevents mixing the payload of separate requests, and prevents
|
|
* transport connects from colliding with writes. No congestion control
|
|
* is provided.
|
|
*/
|
|
int xprt_reserve_xprt(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
|
|
if (task == xprt->snd_task)
|
|
return 1;
|
|
if (task == NULL)
|
|
return 0;
|
|
goto out_sleep;
|
|
}
|
|
xprt->snd_task = task;
|
|
if (req) {
|
|
req->rq_bytes_sent = 0;
|
|
req->rq_ntrans++;
|
|
}
|
|
return 1;
|
|
|
|
out_sleep:
|
|
dprintk("RPC: %5u failed to lock transport %p\n",
|
|
task->tk_pid, xprt);
|
|
task->tk_timeout = 0;
|
|
task->tk_status = -EAGAIN;
|
|
if (req && req->rq_ntrans)
|
|
rpc_sleep_on(&xprt->resend, task, NULL);
|
|
else
|
|
rpc_sleep_on(&xprt->sending, task, NULL);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_reserve_xprt);
|
|
|
|
static void xprt_clear_locked(struct rpc_xprt *xprt)
|
|
{
|
|
xprt->snd_task = NULL;
|
|
if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) {
|
|
smp_mb__before_clear_bit();
|
|
clear_bit(XPRT_LOCKED, &xprt->state);
|
|
smp_mb__after_clear_bit();
|
|
} else
|
|
queue_work(rpciod_workqueue, &xprt->task_cleanup);
|
|
}
|
|
|
|
/*
|
|
* xprt_reserve_xprt_cong - serialize write access to transports
|
|
* @task: task that is requesting access to the transport
|
|
*
|
|
* Same as xprt_reserve_xprt, but Van Jacobson congestion control is
|
|
* integrated into the decision of whether a request is allowed to be
|
|
* woken up and given access to the transport.
|
|
*/
|
|
int xprt_reserve_xprt_cong(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) {
|
|
if (task == xprt->snd_task)
|
|
return 1;
|
|
goto out_sleep;
|
|
}
|
|
if (__xprt_get_cong(xprt, task)) {
|
|
xprt->snd_task = task;
|
|
if (req) {
|
|
req->rq_bytes_sent = 0;
|
|
req->rq_ntrans++;
|
|
}
|
|
return 1;
|
|
}
|
|
xprt_clear_locked(xprt);
|
|
out_sleep:
|
|
dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt);
|
|
task->tk_timeout = 0;
|
|
task->tk_status = -EAGAIN;
|
|
if (req && req->rq_ntrans)
|
|
rpc_sleep_on(&xprt->resend, task, NULL);
|
|
else
|
|
rpc_sleep_on(&xprt->sending, task, NULL);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong);
|
|
|
|
static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task)
|
|
{
|
|
int retval;
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
retval = xprt->ops->reserve_xprt(task);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
return retval;
|
|
}
|
|
|
|
static void __xprt_lock_write_next(struct rpc_xprt *xprt)
|
|
{
|
|
struct rpc_task *task;
|
|
struct rpc_rqst *req;
|
|
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
|
|
return;
|
|
|
|
task = rpc_wake_up_next(&xprt->resend);
|
|
if (!task) {
|
|
task = rpc_wake_up_next(&xprt->sending);
|
|
if (!task)
|
|
goto out_unlock;
|
|
}
|
|
|
|
req = task->tk_rqstp;
|
|
xprt->snd_task = task;
|
|
if (req) {
|
|
req->rq_bytes_sent = 0;
|
|
req->rq_ntrans++;
|
|
}
|
|
return;
|
|
|
|
out_unlock:
|
|
xprt_clear_locked(xprt);
|
|
}
|
|
|
|
static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt)
|
|
{
|
|
struct rpc_task *task;
|
|
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
|
|
return;
|
|
if (RPCXPRT_CONGESTED(xprt))
|
|
goto out_unlock;
|
|
task = rpc_wake_up_next(&xprt->resend);
|
|
if (!task) {
|
|
task = rpc_wake_up_next(&xprt->sending);
|
|
if (!task)
|
|
goto out_unlock;
|
|
}
|
|
if (__xprt_get_cong(xprt, task)) {
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
xprt->snd_task = task;
|
|
if (req) {
|
|
req->rq_bytes_sent = 0;
|
|
req->rq_ntrans++;
|
|
}
|
|
return;
|
|
}
|
|
out_unlock:
|
|
xprt_clear_locked(xprt);
|
|
}
|
|
|
|
/**
|
|
* xprt_release_xprt - allow other requests to use a transport
|
|
* @xprt: transport with other tasks potentially waiting
|
|
* @task: task that is releasing access to the transport
|
|
*
|
|
* Note that "task" can be NULL. No congestion control is provided.
|
|
*/
|
|
void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
|
|
{
|
|
if (xprt->snd_task == task) {
|
|
xprt_clear_locked(xprt);
|
|
__xprt_lock_write_next(xprt);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_release_xprt);
|
|
|
|
/**
|
|
* xprt_release_xprt_cong - allow other requests to use a transport
|
|
* @xprt: transport with other tasks potentially waiting
|
|
* @task: task that is releasing access to the transport
|
|
*
|
|
* Note that "task" can be NULL. Another task is awoken to use the
|
|
* transport if the transport's congestion window allows it.
|
|
*/
|
|
void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task)
|
|
{
|
|
if (xprt->snd_task == task) {
|
|
xprt_clear_locked(xprt);
|
|
__xprt_lock_write_next_cong(xprt);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_release_xprt_cong);
|
|
|
|
static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
|
|
{
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
xprt->ops->release_xprt(xprt, task);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
/*
|
|
* Van Jacobson congestion avoidance. Check if the congestion window
|
|
* overflowed. Put the task to sleep if this is the case.
|
|
*/
|
|
static int
|
|
__xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
|
|
if (req->rq_cong)
|
|
return 1;
|
|
dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n",
|
|
task->tk_pid, xprt->cong, xprt->cwnd);
|
|
if (RPCXPRT_CONGESTED(xprt))
|
|
return 0;
|
|
req->rq_cong = 1;
|
|
xprt->cong += RPC_CWNDSCALE;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Adjust the congestion window, and wake up the next task
|
|
* that has been sleeping due to congestion
|
|
*/
|
|
static void
|
|
__xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req)
|
|
{
|
|
if (!req->rq_cong)
|
|
return;
|
|
req->rq_cong = 0;
|
|
xprt->cong -= RPC_CWNDSCALE;
|
|
__xprt_lock_write_next_cong(xprt);
|
|
}
|
|
|
|
/**
|
|
* xprt_release_rqst_cong - housekeeping when request is complete
|
|
* @task: RPC request that recently completed
|
|
*
|
|
* Useful for transports that require congestion control.
|
|
*/
|
|
void xprt_release_rqst_cong(struct rpc_task *task)
|
|
{
|
|
__xprt_put_cong(task->tk_xprt, task->tk_rqstp);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_release_rqst_cong);
|
|
|
|
/**
|
|
* xprt_adjust_cwnd - adjust transport congestion window
|
|
* @task: recently completed RPC request used to adjust window
|
|
* @result: result code of completed RPC request
|
|
*
|
|
* We use a time-smoothed congestion estimator to avoid heavy oscillation.
|
|
*/
|
|
void xprt_adjust_cwnd(struct rpc_task *task, int result)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
unsigned long cwnd = xprt->cwnd;
|
|
|
|
if (result >= 0 && cwnd <= xprt->cong) {
|
|
/* The (cwnd >> 1) term makes sure
|
|
* the result gets rounded properly. */
|
|
cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd;
|
|
if (cwnd > RPC_MAXCWND(xprt))
|
|
cwnd = RPC_MAXCWND(xprt);
|
|
__xprt_lock_write_next_cong(xprt);
|
|
} else if (result == -ETIMEDOUT) {
|
|
cwnd >>= 1;
|
|
if (cwnd < RPC_CWNDSCALE)
|
|
cwnd = RPC_CWNDSCALE;
|
|
}
|
|
dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n",
|
|
xprt->cong, xprt->cwnd, cwnd);
|
|
xprt->cwnd = cwnd;
|
|
__xprt_put_cong(xprt, req);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_adjust_cwnd);
|
|
|
|
/**
|
|
* xprt_wake_pending_tasks - wake all tasks on a transport's pending queue
|
|
* @xprt: transport with waiting tasks
|
|
* @status: result code to plant in each task before waking it
|
|
*
|
|
*/
|
|
void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status)
|
|
{
|
|
if (status < 0)
|
|
rpc_wake_up_status(&xprt->pending, status);
|
|
else
|
|
rpc_wake_up(&xprt->pending);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks);
|
|
|
|
/**
|
|
* xprt_wait_for_buffer_space - wait for transport output buffer to clear
|
|
* @task: task to be put to sleep
|
|
* @action: function pointer to be executed after wait
|
|
*/
|
|
void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
task->tk_timeout = req->rq_timeout;
|
|
rpc_sleep_on(&xprt->pending, task, action);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space);
|
|
|
|
/**
|
|
* xprt_write_space - wake the task waiting for transport output buffer space
|
|
* @xprt: transport with waiting tasks
|
|
*
|
|
* Can be called in a soft IRQ context, so xprt_write_space never sleeps.
|
|
*/
|
|
void xprt_write_space(struct rpc_xprt *xprt)
|
|
{
|
|
if (unlikely(xprt->shutdown))
|
|
return;
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (xprt->snd_task) {
|
|
dprintk("RPC: write space: waking waiting task on "
|
|
"xprt %p\n", xprt);
|
|
rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task);
|
|
}
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_write_space);
|
|
|
|
/**
|
|
* xprt_set_retrans_timeout_def - set a request's retransmit timeout
|
|
* @task: task whose timeout is to be set
|
|
*
|
|
* Set a request's retransmit timeout based on the transport's
|
|
* default timeout parameters. Used by transports that don't adjust
|
|
* the retransmit timeout based on round-trip time estimation.
|
|
*/
|
|
void xprt_set_retrans_timeout_def(struct rpc_task *task)
|
|
{
|
|
task->tk_timeout = task->tk_rqstp->rq_timeout;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def);
|
|
|
|
/*
|
|
* xprt_set_retrans_timeout_rtt - set a request's retransmit timeout
|
|
* @task: task whose timeout is to be set
|
|
*
|
|
* Set a request's retransmit timeout using the RTT estimator.
|
|
*/
|
|
void xprt_set_retrans_timeout_rtt(struct rpc_task *task)
|
|
{
|
|
int timer = task->tk_msg.rpc_proc->p_timer;
|
|
struct rpc_clnt *clnt = task->tk_client;
|
|
struct rpc_rtt *rtt = clnt->cl_rtt;
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
unsigned long max_timeout = clnt->cl_timeout->to_maxval;
|
|
|
|
task->tk_timeout = rpc_calc_rto(rtt, timer);
|
|
task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries;
|
|
if (task->tk_timeout > max_timeout || task->tk_timeout == 0)
|
|
task->tk_timeout = max_timeout;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt);
|
|
|
|
static void xprt_reset_majortimeo(struct rpc_rqst *req)
|
|
{
|
|
const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
|
|
|
|
req->rq_majortimeo = req->rq_timeout;
|
|
if (to->to_exponential)
|
|
req->rq_majortimeo <<= to->to_retries;
|
|
else
|
|
req->rq_majortimeo += to->to_increment * to->to_retries;
|
|
if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0)
|
|
req->rq_majortimeo = to->to_maxval;
|
|
req->rq_majortimeo += jiffies;
|
|
}
|
|
|
|
/**
|
|
* xprt_adjust_timeout - adjust timeout values for next retransmit
|
|
* @req: RPC request containing parameters to use for the adjustment
|
|
*
|
|
*/
|
|
int xprt_adjust_timeout(struct rpc_rqst *req)
|
|
{
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout;
|
|
int status = 0;
|
|
|
|
if (time_before(jiffies, req->rq_majortimeo)) {
|
|
if (to->to_exponential)
|
|
req->rq_timeout <<= 1;
|
|
else
|
|
req->rq_timeout += to->to_increment;
|
|
if (to->to_maxval && req->rq_timeout >= to->to_maxval)
|
|
req->rq_timeout = to->to_maxval;
|
|
req->rq_retries++;
|
|
} else {
|
|
req->rq_timeout = to->to_initval;
|
|
req->rq_retries = 0;
|
|
xprt_reset_majortimeo(req);
|
|
/* Reset the RTT counters == "slow start" */
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
status = -ETIMEDOUT;
|
|
}
|
|
|
|
if (req->rq_timeout == 0) {
|
|
printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n");
|
|
req->rq_timeout = 5 * HZ;
|
|
}
|
|
return status;
|
|
}
|
|
|
|
static void xprt_autoclose(struct work_struct *work)
|
|
{
|
|
struct rpc_xprt *xprt =
|
|
container_of(work, struct rpc_xprt, task_cleanup);
|
|
|
|
xprt->ops->close(xprt);
|
|
clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
|
|
xprt_release_write(xprt, NULL);
|
|
}
|
|
|
|
/**
|
|
* xprt_disconnect_done - mark a transport as disconnected
|
|
* @xprt: transport to flag for disconnect
|
|
*
|
|
*/
|
|
void xprt_disconnect_done(struct rpc_xprt *xprt)
|
|
{
|
|
dprintk("RPC: disconnected transport %p\n", xprt);
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
xprt_clear_connected(xprt);
|
|
xprt_wake_pending_tasks(xprt, -EAGAIN);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_disconnect_done);
|
|
|
|
/**
|
|
* xprt_force_disconnect - force a transport to disconnect
|
|
* @xprt: transport to disconnect
|
|
*
|
|
*/
|
|
void xprt_force_disconnect(struct rpc_xprt *xprt)
|
|
{
|
|
/* Don't race with the test_bit() in xprt_clear_locked() */
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
|
|
/* Try to schedule an autoclose RPC call */
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
|
|
queue_work(rpciod_workqueue, &xprt->task_cleanup);
|
|
xprt_wake_pending_tasks(xprt, -EAGAIN);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
/**
|
|
* xprt_conditional_disconnect - force a transport to disconnect
|
|
* @xprt: transport to disconnect
|
|
* @cookie: 'connection cookie'
|
|
*
|
|
* This attempts to break the connection if and only if 'cookie' matches
|
|
* the current transport 'connection cookie'. It ensures that we don't
|
|
* try to break the connection more than once when we need to retransmit
|
|
* a batch of RPC requests.
|
|
*
|
|
*/
|
|
void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie)
|
|
{
|
|
/* Don't race with the test_bit() in xprt_clear_locked() */
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (cookie != xprt->connect_cookie)
|
|
goto out;
|
|
if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt))
|
|
goto out;
|
|
set_bit(XPRT_CLOSE_WAIT, &xprt->state);
|
|
/* Try to schedule an autoclose RPC call */
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
|
|
queue_work(rpciod_workqueue, &xprt->task_cleanup);
|
|
xprt_wake_pending_tasks(xprt, -EAGAIN);
|
|
out:
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
static void
|
|
xprt_init_autodisconnect(unsigned long data)
|
|
{
|
|
struct rpc_xprt *xprt = (struct rpc_xprt *)data;
|
|
|
|
spin_lock(&xprt->transport_lock);
|
|
if (!list_empty(&xprt->recv) || xprt->shutdown)
|
|
goto out_abort;
|
|
if (test_and_set_bit(XPRT_LOCKED, &xprt->state))
|
|
goto out_abort;
|
|
spin_unlock(&xprt->transport_lock);
|
|
set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
|
|
queue_work(rpciod_workqueue, &xprt->task_cleanup);
|
|
return;
|
|
out_abort:
|
|
spin_unlock(&xprt->transport_lock);
|
|
}
|
|
|
|
/**
|
|
* xprt_connect - schedule a transport connect operation
|
|
* @task: RPC task that is requesting the connect
|
|
*
|
|
*/
|
|
void xprt_connect(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid,
|
|
xprt, (xprt_connected(xprt) ? "is" : "is not"));
|
|
|
|
if (!xprt_bound(xprt)) {
|
|
task->tk_status = -EAGAIN;
|
|
return;
|
|
}
|
|
if (!xprt_lock_write(xprt, task))
|
|
return;
|
|
|
|
if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state))
|
|
xprt->ops->close(xprt);
|
|
|
|
if (xprt_connected(xprt))
|
|
xprt_release_write(xprt, task);
|
|
else {
|
|
if (task->tk_rqstp)
|
|
task->tk_rqstp->rq_bytes_sent = 0;
|
|
|
|
task->tk_timeout = task->tk_rqstp->rq_timeout;
|
|
rpc_sleep_on(&xprt->pending, task, xprt_connect_status);
|
|
|
|
if (test_bit(XPRT_CLOSING, &xprt->state))
|
|
return;
|
|
if (xprt_test_and_set_connecting(xprt))
|
|
return;
|
|
xprt->stat.connect_start = jiffies;
|
|
xprt->ops->connect(task);
|
|
}
|
|
}
|
|
|
|
static void xprt_connect_status(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
if (task->tk_status == 0) {
|
|
xprt->stat.connect_count++;
|
|
xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start;
|
|
dprintk("RPC: %5u xprt_connect_status: connection established\n",
|
|
task->tk_pid);
|
|
return;
|
|
}
|
|
|
|
switch (task->tk_status) {
|
|
case -EAGAIN:
|
|
dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid);
|
|
break;
|
|
case -ETIMEDOUT:
|
|
dprintk("RPC: %5u xprt_connect_status: connect attempt timed "
|
|
"out\n", task->tk_pid);
|
|
break;
|
|
default:
|
|
dprintk("RPC: %5u xprt_connect_status: error %d connecting to "
|
|
"server %s\n", task->tk_pid, -task->tk_status,
|
|
task->tk_client->cl_server);
|
|
xprt_release_write(xprt, task);
|
|
task->tk_status = -EIO;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* xprt_lookup_rqst - find an RPC request corresponding to an XID
|
|
* @xprt: transport on which the original request was transmitted
|
|
* @xid: RPC XID of incoming reply
|
|
*
|
|
*/
|
|
struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid)
|
|
{
|
|
struct list_head *pos;
|
|
|
|
list_for_each(pos, &xprt->recv) {
|
|
struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list);
|
|
if (entry->rq_xid == xid)
|
|
return entry;
|
|
}
|
|
|
|
dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n",
|
|
ntohl(xid));
|
|
xprt->stat.bad_xids++;
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_lookup_rqst);
|
|
|
|
static void xprt_update_rtt(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_rtt *rtt = task->tk_client->cl_rtt;
|
|
unsigned timer = task->tk_msg.rpc_proc->p_timer;
|
|
long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt));
|
|
|
|
if (timer) {
|
|
if (req->rq_ntrans == 1)
|
|
rpc_update_rtt(rtt, timer, m);
|
|
rpc_set_timeo(rtt, timer, req->rq_ntrans - 1);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* xprt_complete_rqst - called when reply processing is complete
|
|
* @task: RPC request that recently completed
|
|
* @copied: actual number of bytes received from the transport
|
|
*
|
|
* Caller holds transport lock.
|
|
*/
|
|
void xprt_complete_rqst(struct rpc_task *task, int copied)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
dprintk("RPC: %5u xid %08x complete (%d bytes received)\n",
|
|
task->tk_pid, ntohl(req->rq_xid), copied);
|
|
|
|
xprt->stat.recvs++;
|
|
req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime);
|
|
if (xprt->ops->timer != NULL)
|
|
xprt_update_rtt(task);
|
|
|
|
list_del_init(&req->rq_list);
|
|
req->rq_private_buf.len = copied;
|
|
/* Ensure all writes are done before we update */
|
|
/* req->rq_reply_bytes_recvd */
|
|
smp_wmb();
|
|
req->rq_reply_bytes_recvd = copied;
|
|
rpc_wake_up_queued_task(&xprt->pending, task);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xprt_complete_rqst);
|
|
|
|
static void xprt_timer(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
|
|
if (task->tk_status != -ETIMEDOUT)
|
|
return;
|
|
dprintk("RPC: %5u xprt_timer\n", task->tk_pid);
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (!req->rq_reply_bytes_recvd) {
|
|
if (xprt->ops->timer)
|
|
xprt->ops->timer(task);
|
|
} else
|
|
task->tk_status = 0;
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
static inline int xprt_has_timer(struct rpc_xprt *xprt)
|
|
{
|
|
return xprt->idle_timeout != 0;
|
|
}
|
|
|
|
/**
|
|
* xprt_prepare_transmit - reserve the transport before sending a request
|
|
* @task: RPC task about to send a request
|
|
*
|
|
*/
|
|
int xprt_prepare_transmit(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
int err = 0;
|
|
|
|
dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid);
|
|
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) {
|
|
err = req->rq_reply_bytes_recvd;
|
|
goto out_unlock;
|
|
}
|
|
if (!xprt->ops->reserve_xprt(task))
|
|
err = -EAGAIN;
|
|
out_unlock:
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
return err;
|
|
}
|
|
|
|
void xprt_end_transmit(struct rpc_task *task)
|
|
{
|
|
xprt_release_write(task->tk_rqstp->rq_xprt, task);
|
|
}
|
|
|
|
/**
|
|
* xprt_transmit - send an RPC request on a transport
|
|
* @task: controlling RPC task
|
|
*
|
|
* We have to copy the iovec because sendmsg fiddles with its contents.
|
|
*/
|
|
void xprt_transmit(struct rpc_task *task)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
struct rpc_xprt *xprt = req->rq_xprt;
|
|
int status;
|
|
|
|
dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
|
|
|
|
if (!req->rq_reply_bytes_recvd) {
|
|
if (list_empty(&req->rq_list) && rpc_reply_expected(task)) {
|
|
/*
|
|
* Add to the list only if we're expecting a reply
|
|
*/
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
/* Update the softirq receive buffer */
|
|
memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
|
|
sizeof(req->rq_private_buf));
|
|
/* Add request to the receive list */
|
|
list_add_tail(&req->rq_list, &xprt->recv);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
xprt_reset_majortimeo(req);
|
|
/* Turn off autodisconnect */
|
|
del_singleshot_timer_sync(&xprt->timer);
|
|
}
|
|
} else if (!req->rq_bytes_sent)
|
|
return;
|
|
|
|
req->rq_connect_cookie = xprt->connect_cookie;
|
|
req->rq_xtime = ktime_get();
|
|
status = xprt->ops->send_request(task);
|
|
if (status != 0) {
|
|
task->tk_status = status;
|
|
return;
|
|
}
|
|
|
|
dprintk("RPC: %5u xmit complete\n", task->tk_pid);
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
|
|
xprt->ops->set_retrans_timeout(task);
|
|
|
|
xprt->stat.sends++;
|
|
xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs;
|
|
xprt->stat.bklog_u += xprt->backlog.qlen;
|
|
|
|
/* Don't race with disconnect */
|
|
if (!xprt_connected(xprt))
|
|
task->tk_status = -ENOTCONN;
|
|
else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) {
|
|
/*
|
|
* Sleep on the pending queue since
|
|
* we're expecting a reply.
|
|
*/
|
|
rpc_sleep_on(&xprt->pending, task, xprt_timer);
|
|
}
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
}
|
|
|
|
static void xprt_alloc_slot(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
task->tk_status = 0;
|
|
if (task->tk_rqstp)
|
|
return;
|
|
if (!list_empty(&xprt->free)) {
|
|
struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list);
|
|
list_del_init(&req->rq_list);
|
|
task->tk_rqstp = req;
|
|
xprt_request_init(task, xprt);
|
|
return;
|
|
}
|
|
dprintk("RPC: waiting for request slot\n");
|
|
task->tk_status = -EAGAIN;
|
|
task->tk_timeout = 0;
|
|
rpc_sleep_on(&xprt->backlog, task, NULL);
|
|
}
|
|
|
|
static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req)
|
|
{
|
|
memset(req, 0, sizeof(*req)); /* mark unused */
|
|
|
|
spin_lock(&xprt->reserve_lock);
|
|
list_add(&req->rq_list, &xprt->free);
|
|
rpc_wake_up_next(&xprt->backlog);
|
|
spin_unlock(&xprt->reserve_lock);
|
|
}
|
|
|
|
/**
|
|
* xprt_reserve - allocate an RPC request slot
|
|
* @task: RPC task requesting a slot allocation
|
|
*
|
|
* If no more slots are available, place the task on the transport's
|
|
* backlog queue.
|
|
*/
|
|
void xprt_reserve(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt = task->tk_xprt;
|
|
|
|
task->tk_status = -EIO;
|
|
spin_lock(&xprt->reserve_lock);
|
|
xprt_alloc_slot(task);
|
|
spin_unlock(&xprt->reserve_lock);
|
|
}
|
|
|
|
static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt)
|
|
{
|
|
return (__force __be32)xprt->xid++;
|
|
}
|
|
|
|
static inline void xprt_init_xid(struct rpc_xprt *xprt)
|
|
{
|
|
xprt->xid = net_random();
|
|
}
|
|
|
|
static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt)
|
|
{
|
|
struct rpc_rqst *req = task->tk_rqstp;
|
|
|
|
req->rq_timeout = task->tk_client->cl_timeout->to_initval;
|
|
req->rq_task = task;
|
|
req->rq_xprt = xprt;
|
|
req->rq_buffer = NULL;
|
|
req->rq_xid = xprt_alloc_xid(xprt);
|
|
req->rq_release_snd_buf = NULL;
|
|
xprt_reset_majortimeo(req);
|
|
dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
|
|
req, ntohl(req->rq_xid));
|
|
}
|
|
|
|
/**
|
|
* xprt_release - release an RPC request slot
|
|
* @task: task which is finished with the slot
|
|
*
|
|
*/
|
|
void xprt_release(struct rpc_task *task)
|
|
{
|
|
struct rpc_xprt *xprt;
|
|
struct rpc_rqst *req;
|
|
|
|
if (!(req = task->tk_rqstp))
|
|
return;
|
|
|
|
xprt = req->rq_xprt;
|
|
rpc_count_iostats(task);
|
|
spin_lock_bh(&xprt->transport_lock);
|
|
xprt->ops->release_xprt(xprt, task);
|
|
if (xprt->ops->release_request)
|
|
xprt->ops->release_request(task);
|
|
if (!list_empty(&req->rq_list))
|
|
list_del(&req->rq_list);
|
|
xprt->last_used = jiffies;
|
|
if (list_empty(&xprt->recv) && xprt_has_timer(xprt))
|
|
mod_timer(&xprt->timer,
|
|
xprt->last_used + xprt->idle_timeout);
|
|
spin_unlock_bh(&xprt->transport_lock);
|
|
if (req->rq_buffer)
|
|
xprt->ops->buf_free(req->rq_buffer);
|
|
if (req->rq_cred != NULL)
|
|
put_rpccred(req->rq_cred);
|
|
task->tk_rqstp = NULL;
|
|
if (req->rq_release_snd_buf)
|
|
req->rq_release_snd_buf(req);
|
|
|
|
dprintk("RPC: %5u release request %p\n", task->tk_pid, req);
|
|
if (likely(!bc_prealloc(req)))
|
|
xprt_free_slot(xprt, req);
|
|
else
|
|
xprt_free_bc_request(req);
|
|
}
|
|
|
|
/**
|
|
* xprt_create_transport - create an RPC transport
|
|
* @args: rpc transport creation arguments
|
|
*
|
|
*/
|
|
struct rpc_xprt *xprt_create_transport(struct xprt_create *args)
|
|
{
|
|
struct rpc_xprt *xprt;
|
|
struct rpc_rqst *req;
|
|
struct xprt_class *t;
|
|
|
|
spin_lock(&xprt_list_lock);
|
|
list_for_each_entry(t, &xprt_list, list) {
|
|
if (t->ident == args->ident) {
|
|
spin_unlock(&xprt_list_lock);
|
|
goto found;
|
|
}
|
|
}
|
|
spin_unlock(&xprt_list_lock);
|
|
printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident);
|
|
return ERR_PTR(-EIO);
|
|
|
|
found:
|
|
xprt = t->setup(args);
|
|
if (IS_ERR(xprt)) {
|
|
dprintk("RPC: xprt_create_transport: failed, %ld\n",
|
|
-PTR_ERR(xprt));
|
|
return xprt;
|
|
}
|
|
|
|
kref_init(&xprt->kref);
|
|
spin_lock_init(&xprt->transport_lock);
|
|
spin_lock_init(&xprt->reserve_lock);
|
|
|
|
INIT_LIST_HEAD(&xprt->free);
|
|
INIT_LIST_HEAD(&xprt->recv);
|
|
#if defined(CONFIG_NFS_V4_1)
|
|
spin_lock_init(&xprt->bc_pa_lock);
|
|
INIT_LIST_HEAD(&xprt->bc_pa_list);
|
|
#endif /* CONFIG_NFS_V4_1 */
|
|
|
|
INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
|
|
if (xprt_has_timer(xprt))
|
|
setup_timer(&xprt->timer, xprt_init_autodisconnect,
|
|
(unsigned long)xprt);
|
|
else
|
|
init_timer(&xprt->timer);
|
|
xprt->last_used = jiffies;
|
|
xprt->cwnd = RPC_INITCWND;
|
|
xprt->bind_index = 0;
|
|
|
|
rpc_init_wait_queue(&xprt->binding, "xprt_binding");
|
|
rpc_init_wait_queue(&xprt->pending, "xprt_pending");
|
|
rpc_init_wait_queue(&xprt->sending, "xprt_sending");
|
|
rpc_init_wait_queue(&xprt->resend, "xprt_resend");
|
|
rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
|
|
|
|
/* initialize free list */
|
|
for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--)
|
|
list_add(&req->rq_list, &xprt->free);
|
|
|
|
xprt_init_xid(xprt);
|
|
|
|
dprintk("RPC: created transport %p with %u slots\n", xprt,
|
|
xprt->max_reqs);
|
|
return xprt;
|
|
}
|
|
|
|
/**
|
|
* xprt_destroy - destroy an RPC transport, killing off all requests.
|
|
* @kref: kref for the transport to destroy
|
|
*
|
|
*/
|
|
static void xprt_destroy(struct kref *kref)
|
|
{
|
|
struct rpc_xprt *xprt = container_of(kref, struct rpc_xprt, kref);
|
|
|
|
dprintk("RPC: destroying transport %p\n", xprt);
|
|
xprt->shutdown = 1;
|
|
del_timer_sync(&xprt->timer);
|
|
|
|
rpc_destroy_wait_queue(&xprt->binding);
|
|
rpc_destroy_wait_queue(&xprt->pending);
|
|
rpc_destroy_wait_queue(&xprt->sending);
|
|
rpc_destroy_wait_queue(&xprt->resend);
|
|
rpc_destroy_wait_queue(&xprt->backlog);
|
|
cancel_work_sync(&xprt->task_cleanup);
|
|
/*
|
|
* Tear down transport state and free the rpc_xprt
|
|
*/
|
|
xprt->ops->destroy(xprt);
|
|
}
|
|
|
|
/**
|
|
* xprt_put - release a reference to an RPC transport.
|
|
* @xprt: pointer to the transport
|
|
*
|
|
*/
|
|
void xprt_put(struct rpc_xprt *xprt)
|
|
{
|
|
kref_put(&xprt->kref, xprt_destroy);
|
|
}
|
|
|
|
/**
|
|
* xprt_get - return a reference to an RPC transport.
|
|
* @xprt: pointer to the transport
|
|
*
|
|
*/
|
|
struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
|
|
{
|
|
kref_get(&xprt->kref);
|
|
return xprt;
|
|
}
|