svcrpc: break up svc_recv

Matter of taste, I suppose, but svc_recv breaks up naturally into:

	allocate pages and setup arg
	dequeue (wait for, if necessary) next socket
	do something with that socket

And I find it easier to read when it doesn't go on for pages and pages.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2012-08-18 15:33:51 -04:00
parent 6741019c82
commit 6797fa5a01
1 changed files with 67 additions and 36 deletions

View File

@ -568,33 +568,12 @@ static void svc_check_conn_limits(struct svc_serv *serv)
}
}
/*
* Receive the next request on any transport. This code is carefully
* organised not to touch any cachelines in the shared svc_serv
* structure, only cachelines in the local svc_pool.
*/
int svc_recv(struct svc_rqst *rqstp, long timeout)
int svc_alloc_arg(struct svc_rqst *rqstp)
{
struct svc_xprt *xprt = NULL;
struct svc_serv *serv = rqstp->rq_server;
struct svc_pool *pool = rqstp->rq_pool;
int len, i;
int pages;
struct xdr_buf *arg;
DECLARE_WAITQUEUE(wait, current);
long time_left;
dprintk("svc: server %p waiting for data (to = %ld)\n",
rqstp, timeout);
if (rqstp->rq_xprt)
printk(KERN_ERR
"svc_recv: service %p, transport not NULL!\n",
rqstp);
if (waitqueue_active(&rqstp->rq_wait))
printk(KERN_ERR
"svc_recv: service %p, wait queue active!\n",
rqstp);
struct svc_serv *serv = rqstp->rq_server;
struct xdr_buf *arg;
int pages;
int i;
/* now allocate needed pages. If we get a failure, sleep briefly */
pages = (serv->sv_max_mesg + PAGE_SIZE) / PAGE_SIZE;
@ -624,11 +603,15 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
arg->page_len = (pages-2)*PAGE_SIZE;
arg->len = (pages-1)*PAGE_SIZE;
arg->tail[0].iov_len = 0;
return 0;
}
try_to_freeze();
cond_resched();
if (signalled() || kthread_should_stop())
return -EINTR;
struct svc_xprt *svc_get_next_xprt(struct svc_rqst *rqstp, long timeout)
{
struct svc_xprt *xprt;
struct svc_pool *pool = rqstp->rq_pool;
DECLARE_WAITQUEUE(wait, current);
long time_left;
/* Normally we will wait up to 5 seconds for any required
* cache information to be provided.
@ -666,7 +649,7 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
if (kthread_should_stop()) {
set_current_state(TASK_RUNNING);
spin_unlock_bh(&pool->sp_lock);
return -EINTR;
return ERR_PTR(-EINTR);
}
add_wait_queue(&rqstp->rq_wait, &wait);
@ -687,19 +670,25 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
spin_unlock_bh(&pool->sp_lock);
dprintk("svc: server %p, no data yet\n", rqstp);
if (signalled() || kthread_should_stop())
return -EINTR;
return ERR_PTR(-EINTR);
else
return -EAGAIN;
return ERR_PTR(-EAGAIN);
}
}
spin_unlock_bh(&pool->sp_lock);
return xprt;
}
static int svc_handle_xprt(struct svc_rqst *rqstp, struct svc_xprt *xprt)
{
struct svc_serv *serv = rqstp->rq_server;
int len = 0;
len = 0;
if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) {
dprintk("svc_recv: found XPT_CLOSE\n");
svc_delete_xprt(xprt);
/* Leave XPT_BUSY set on the dead xprt: */
goto out;
return 0;
}
if (test_bit(XPT_LISTENER, &xprt->xpt_flags)) {
struct svc_xprt *newxpt;
@ -727,8 +716,9 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
svc_xprt_received(newxpt);
}
} else if (xprt->xpt_ops->xpo_has_wspace(xprt)) {
/* XPT_DATA|XPT_DEFERRED case: */
dprintk("svc: server %p, pool %u, transport %p, inuse=%d\n",
rqstp, pool->sp_id, xprt,
rqstp, rqstp->rq_pool->sp_id, xprt,
atomic_read(&xprt->xpt_ref.refcount));
rqstp->rq_deferred = svc_deferred_dequeue(xprt);
if (rqstp->rq_deferred)
@ -739,7 +729,48 @@ int svc_recv(struct svc_rqst *rqstp, long timeout)
rqstp->rq_reserved = serv->sv_max_mesg;
atomic_add(rqstp->rq_reserved, &xprt->xpt_reserved);
}
/* clear XPT_BUSY: */
svc_xprt_received(xprt);
return len;
}
/*
* Receive the next request on any transport. This code is carefully
* organised not to touch any cachelines in the shared svc_serv
* structure, only cachelines in the local svc_pool.
*/
int svc_recv(struct svc_rqst *rqstp, long timeout)
{
struct svc_xprt *xprt = NULL;
struct svc_serv *serv = rqstp->rq_server;
int len, err;
dprintk("svc: server %p waiting for data (to = %ld)\n",
rqstp, timeout);
if (rqstp->rq_xprt)
printk(KERN_ERR
"svc_recv: service %p, transport not NULL!\n",
rqstp);
if (waitqueue_active(&rqstp->rq_wait))
printk(KERN_ERR
"svc_recv: service %p, wait queue active!\n",
rqstp);
err = svc_alloc_arg(rqstp);
if (err)
return err;
try_to_freeze();
cond_resched();
if (signalled() || kthread_should_stop())
return -EINTR;
xprt = svc_get_next_xprt(rqstp, timeout);
if (IS_ERR(xprt))
return PTR_ERR(xprt);
len = svc_handle_xprt(rqstp, xprt);
/* No data, incomplete (TCP) read, or accept() */
if (len <= 0)