nfsd41: sunrpc: Added rpc server-side backchannel handling
When the call direction is a reply, copy the xid and call direction into the
req->rq_private_buf.head[0].iov_base otherwise rpc_verify_header returns
rpc_garbage.
Signed-off-by: Rahul Iyer <iyer@netapp.com>
Signed-off-by: Mike Sager <sager@netapp.com>
Signed-off-by: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[get rid of CONFIG_NFSD_V4_1]
[sunrpc: refactoring of svc_tcp_recvfrom]
[nfsd41: sunrpc: create common send routine for the fore and the back channels]
[nfsd41: sunrpc: Use free_page() to free server backchannel pages]
[nfsd41: sunrpc: Document server backchannel locking]
[nfsd41: sunrpc: remove bc_connect_worker()]
[nfsd41: sunrpc: Define xprt_server_backchannel()[
[nfsd41: sunrpc: remove bc_close and bc_init_auto_disconnect dummy functions]
[nfsd41: sunrpc: eliminate unneeded switch statement in xs_setup_tcp()]
[nfsd41: sunrpc: Don't auto close the server backchannel connection]
[nfsd41: sunrpc: Remove unused functions]
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfsd41: change bc_sock to bc_xprt]
[nfsd41: sunrpc: move struct rpc_buffer def into a common header file]
[nfsd41: sunrpc: use rpc_sleep in bc_send_request so not to block on mutex]
[removed cosmetic changes]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[sunrpc: add new xprt class for nfsv4.1 backchannel]
[sunrpc: v2.1 change handling of auto_close and init_auto_disconnect operations for the nfsv4.1 backchannel]
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
[reverted more cosmetic leftovers]
[got rid of xprt_server_backchannel]
[separated "nfsd41: sunrpc: add new xprt class for nfsv4.1 backchannel"]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Cc: Trond Myklebust <trond.myklebust@netapp.com>
[sunrpc: change idle timeout value for the backchannel]
Signed-off-by: Alexandros Batsakis <batsakis@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Acked-by: Trond Myklebust <trond.myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/net/sunrpc/sunrpc.h b/net/sunrpc/sunrpc.h
index 13171e6..90c292e 100644
--- a/net/sunrpc/sunrpc.h
+++ b/net/sunrpc/sunrpc.h
@@ -43,5 +43,9 @@
(task->tk_msg.rpc_proc->p_decode != NULL);
}
+int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
+ struct page *headpage, unsigned long headoffset,
+ struct page *tailpage, unsigned long tailoffset);
+
#endif /* _NET_SUNRPC_SUNRPC_H */
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 912dea5..df124f7 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -160,6 +160,7 @@
mutex_init(&xprt->xpt_mutex);
spin_lock_init(&xprt->xpt_lock);
set_bit(XPT_BUSY, &xprt->xpt_flags);
+ rpc_init_wait_queue(&xprt->xpt_bc_pending, "xpt_bc_pending");
}
EXPORT_SYMBOL_GPL(svc_xprt_init);
@@ -810,6 +811,7 @@
else
len = xprt->xpt_ops->xpo_sendto(rqstp);
mutex_unlock(&xprt->xpt_mutex);
+ rpc_wake_up(&xprt->xpt_bc_pending);
svc_xprt_release(rqstp);
if (len == -ECONNREFUSED || len == -ENOTCONN || len == -EAGAIN)
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 76a380d..ccc5e83 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -49,6 +49,7 @@
#include <linux/sunrpc/msg_prot.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/stats.h>
+#include <linux/sunrpc/xprt.h>
#define RPCDBG_FACILITY RPCDBG_SVCXPRT
@@ -153,49 +154,27 @@
}
/*
- * Generic sendto routine
+ * send routine intended to be shared by the fore- and back-channel
*/
-static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
+int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
+ struct page *headpage, unsigned long headoffset,
+ struct page *tailpage, unsigned long tailoffset)
{
- struct svc_sock *svsk =
- container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
- struct socket *sock = svsk->sk_sock;
- int slen;
- union {
- struct cmsghdr hdr;
- long all[SVC_PKTINFO_SPACE / sizeof(long)];
- } buffer;
- struct cmsghdr *cmh = &buffer.hdr;
- int len = 0;
int result;
int size;
struct page **ppage = xdr->pages;
size_t base = xdr->page_base;
unsigned int pglen = xdr->page_len;
unsigned int flags = MSG_MORE;
- RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+ int slen;
+ int len = 0;
slen = xdr->len;
- if (rqstp->rq_prot == IPPROTO_UDP) {
- struct msghdr msg = {
- .msg_name = &rqstp->rq_addr,
- .msg_namelen = rqstp->rq_addrlen,
- .msg_control = cmh,
- .msg_controllen = sizeof(buffer),
- .msg_flags = MSG_MORE,
- };
-
- svc_set_cmsg_data(rqstp, cmh);
-
- if (sock_sendmsg(sock, &msg, 0) < 0)
- goto out;
- }
-
/* send head */
if (slen == xdr->head[0].iov_len)
flags = 0;
- len = kernel_sendpage(sock, rqstp->rq_respages[0], 0,
+ len = kernel_sendpage(sock, headpage, headoffset,
xdr->head[0].iov_len, flags);
if (len != xdr->head[0].iov_len)
goto out;
@@ -219,16 +198,58 @@
base = 0;
ppage++;
}
+
/* send tail */
if (xdr->tail[0].iov_len) {
- result = kernel_sendpage(sock, rqstp->rq_respages[0],
- ((unsigned long)xdr->tail[0].iov_base)
- & (PAGE_SIZE-1),
- xdr->tail[0].iov_len, 0);
-
+ result = kernel_sendpage(sock, tailpage, tailoffset,
+ xdr->tail[0].iov_len, 0);
if (result > 0)
len += result;
}
+
+out:
+ return len;
+}
+
+
+/*
+ * Generic sendto routine
+ */
+static int svc_sendto(struct svc_rqst *rqstp, struct xdr_buf *xdr)
+{
+ struct svc_sock *svsk =
+ container_of(rqstp->rq_xprt, struct svc_sock, sk_xprt);
+ struct socket *sock = svsk->sk_sock;
+ union {
+ struct cmsghdr hdr;
+ long all[SVC_PKTINFO_SPACE / sizeof(long)];
+ } buffer;
+ struct cmsghdr *cmh = &buffer.hdr;
+ int len = 0;
+ unsigned long tailoff;
+ unsigned long headoff;
+ RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
+
+ if (rqstp->rq_prot == IPPROTO_UDP) {
+ struct msghdr msg = {
+ .msg_name = &rqstp->rq_addr,
+ .msg_namelen = rqstp->rq_addrlen,
+ .msg_control = cmh,
+ .msg_controllen = sizeof(buffer),
+ .msg_flags = MSG_MORE,
+ };
+
+ svc_set_cmsg_data(rqstp, cmh);
+
+ if (sock_sendmsg(sock, &msg, 0) < 0)
+ goto out;
+ }
+
+ tailoff = ((unsigned long)xdr->tail[0].iov_base) & (PAGE_SIZE-1);
+ headoff = 0;
+ len = svc_send_common(sock, xdr, rqstp->rq_respages[0], headoff,
+ rqstp->rq_respages[0], tailoff);
+
out:
dprintk("svc: socket %p sendto([%p %Zu... ], %d) = %d (addr %s)\n",
svsk, xdr->head[0].iov_base, xdr->head[0].iov_len,
@@ -951,6 +972,57 @@
return -EAGAIN;
}
+static int svc_process_calldir(struct svc_sock *svsk, struct svc_rqst *rqstp,
+ struct rpc_rqst **reqpp, struct kvec *vec)
+{
+ struct rpc_rqst *req = NULL;
+ u32 *p;
+ u32 xid;
+ u32 calldir;
+ int len;
+
+ len = svc_recvfrom(rqstp, vec, 1, 8);
+ if (len < 0)
+ goto error;
+
+ p = (u32 *)rqstp->rq_arg.head[0].iov_base;
+ xid = *p++;
+ calldir = *p;
+
+ if (calldir == 0) {
+ /* REQUEST is the most common case */
+ vec[0] = rqstp->rq_arg.head[0];
+ } else {
+ /* REPLY */
+ if (svsk->sk_bc_xprt)
+ req = xprt_lookup_rqst(svsk->sk_bc_xprt, xid);
+
+ if (!req) {
+ printk(KERN_NOTICE
+ "%s: Got unrecognized reply: "
+ "calldir 0x%x sk_bc_xprt %p xid %08x\n",
+ __func__, ntohl(calldir),
+ svsk->sk_bc_xprt, xid);
+ vec[0] = rqstp->rq_arg.head[0];
+ goto out;
+ }
+
+ memcpy(&req->rq_private_buf, &req->rq_rcv_buf,
+ sizeof(struct xdr_buf));
+ /* copy the xid and call direction */
+ memcpy(req->rq_private_buf.head[0].iov_base,
+ rqstp->rq_arg.head[0].iov_base, 8);
+ vec[0] = req->rq_private_buf.head[0];
+ }
+ out:
+ vec[0].iov_base += 8;
+ vec[0].iov_len -= 8;
+ len = svsk->sk_reclen - 8;
+ error:
+ *reqpp = req;
+ return len;
+}
+
/*
* Receive data from a TCP socket.
*/
@@ -962,6 +1034,7 @@
int len;
struct kvec *vec;
int pnum, vlen;
+ struct rpc_rqst *req = NULL;
dprintk("svc: tcp_recv %p data %d conn %d close %d\n",
svsk, test_bit(XPT_DATA, &svsk->sk_xprt.xpt_flags),
@@ -975,9 +1048,27 @@
vec = rqstp->rq_vec;
vec[0] = rqstp->rq_arg.head[0];
vlen = PAGE_SIZE;
+
+ /*
+ * We have enough data for the whole tcp record. Let's try and read the
+ * first 8 bytes to get the xid and the call direction. We can use this
+ * to figure out if this is a call or a reply to a callback. If
+ * sk_reclen is < 8 (xid and calldir), then this is a malformed packet.
+ * In that case, don't bother with the calldir and just read the data.
+ * It will be rejected in svc_process.
+ */
+ if (len >= 8) {
+ len = svc_process_calldir(svsk, rqstp, &req, vec);
+ if (len < 0)
+ goto err_again;
+ vlen -= 8;
+ }
+
pnum = 1;
while (vlen < len) {
- vec[pnum].iov_base = page_address(rqstp->rq_pages[pnum]);
+ vec[pnum].iov_base = (req) ?
+ page_address(req->rq_private_buf.pages[pnum - 1]) :
+ page_address(rqstp->rq_pages[pnum]);
vec[pnum].iov_len = PAGE_SIZE;
pnum++;
vlen += PAGE_SIZE;
@@ -989,6 +1080,16 @@
if (len < 0)
goto err_again;
+ /*
+ * Account for the 8 bytes we read earlier
+ */
+ len += 8;
+
+ if (req) {
+ xprt_complete_rqst(req->rq_task, len);
+ len = 0;
+ goto out;
+ }
dprintk("svc: TCP complete record (%d bytes)\n", len);
rqstp->rq_arg.len = len;
rqstp->rq_arg.page_base = 0;
@@ -1002,6 +1103,7 @@
rqstp->rq_xprt_ctxt = NULL;
rqstp->rq_prot = IPPROTO_TCP;
+out:
/* Reset TCP read info */
svsk->sk_reclen = 0;
svsk->sk_tcplen = 0;
diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index f412a85..fd46d42 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -832,6 +832,11 @@
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
@@ -1013,7 +1018,7 @@
if (!list_empty(&req->rq_list))
list_del(&req->rq_list);
xprt->last_used = jiffies;
- if (list_empty(&xprt->recv))
+ 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);
@@ -1082,8 +1087,11 @@
#endif /* CONFIG_NFS_V4_1 */
INIT_WORK(&xprt->task_cleanup, xprt_autoclose);
- setup_timer(&xprt->timer, xprt_init_autodisconnect,
- (unsigned long)xprt);
+ 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;
@@ -1102,7 +1110,6 @@
dprintk("RPC: created transport %p with %u slots\n", xprt,
xprt->max_reqs);
-
return xprt;
}
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 62438f3..d9a2b81 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -32,6 +32,7 @@
#include <linux/tcp.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/xprtsock.h>
#include <linux/file.h>
#ifdef CONFIG_NFS_V4_1
@@ -43,6 +44,7 @@
#include <net/udp.h>
#include <net/tcp.h>
+#include "sunrpc.h"
/*
* xprtsock tunables
*/
@@ -2098,6 +2100,134 @@
xprt->stat.bklog_u);
}
+/*
+ * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
+ * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
+ * to use the server side send routines.
+ */
+void *bc_malloc(struct rpc_task *task, size_t size)
+{
+ struct page *page;
+ struct rpc_buffer *buf;
+
+ BUG_ON(size > PAGE_SIZE - sizeof(struct rpc_buffer));
+ page = alloc_page(GFP_KERNEL);
+
+ if (!page)
+ return NULL;
+
+ buf = page_address(page);
+ buf->len = PAGE_SIZE;
+
+ return buf->data;
+}
+
+/*
+ * Free the space allocated in the bc_alloc routine
+ */
+void bc_free(void *buffer)
+{
+ struct rpc_buffer *buf;
+
+ if (!buffer)
+ return;
+
+ buf = container_of(buffer, struct rpc_buffer, data);
+ free_page((unsigned long)buf);
+}
+
+/*
+ * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
+ * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
+ */
+static int bc_sendto(struct rpc_rqst *req)
+{
+ int len;
+ struct xdr_buf *xbufp = &req->rq_snd_buf;
+ struct rpc_xprt *xprt = req->rq_xprt;
+ struct sock_xprt *transport =
+ container_of(xprt, struct sock_xprt, xprt);
+ struct socket *sock = transport->sock;
+ unsigned long headoff;
+ unsigned long tailoff;
+
+ /*
+ * Set up the rpc header and record marker stuff
+ */
+ xs_encode_tcp_record_marker(xbufp);
+
+ tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
+ headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
+ len = svc_send_common(sock, xbufp,
+ virt_to_page(xbufp->head[0].iov_base), headoff,
+ xbufp->tail[0].iov_base, tailoff);
+
+ if (len != xbufp->len) {
+ printk(KERN_NOTICE "Error sending entire callback!\n");
+ len = -EAGAIN;
+ }
+
+ return len;
+}
+
+/*
+ * The send routine. Borrows from svc_send
+ */
+static int bc_send_request(struct rpc_task *task)
+{
+ struct rpc_rqst *req = task->tk_rqstp;
+ struct svc_xprt *xprt;
+ struct svc_sock *svsk;
+ u32 len;
+
+ dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
+ /*
+ * Get the server socket associated with this callback xprt
+ */
+ xprt = req->rq_xprt->bc_xprt;
+ svsk = container_of(xprt, struct svc_sock, sk_xprt);
+
+ /*
+ * Grab the mutex to serialize data as the connection is shared
+ * with the fore channel
+ */
+ if (!mutex_trylock(&xprt->xpt_mutex)) {
+ rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
+ if (!mutex_trylock(&xprt->xpt_mutex))
+ return -EAGAIN;
+ rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
+ }
+ if (test_bit(XPT_DEAD, &xprt->xpt_flags))
+ len = -ENOTCONN;
+ else
+ len = bc_sendto(req);
+ mutex_unlock(&xprt->xpt_mutex);
+
+ if (len > 0)
+ len = 0;
+
+ return len;
+}
+
+/*
+ * The close routine. Since this is client initiated, we do nothing
+ */
+
+static void bc_close(struct rpc_xprt *xprt)
+{
+ return;
+}
+
+/*
+ * The xprt destroy routine. Again, because this connection is client
+ * initiated, we do nothing
+ */
+
+static void bc_destroy(struct rpc_xprt *xprt)
+{
+ return;
+}
+
static struct rpc_xprt_ops xs_udp_ops = {
.set_buffer_size = xs_udp_set_buffer_size,
.reserve_xprt = xprt_reserve_xprt_cong,
@@ -2134,6 +2264,22 @@
.print_stats = xs_tcp_print_stats,
};
+/*
+ * The rpc_xprt_ops for the server backchannel
+ */
+
+static struct rpc_xprt_ops bc_tcp_ops = {
+ .reserve_xprt = xprt_reserve_xprt,
+ .release_xprt = xprt_release_xprt,
+ .buf_alloc = bc_malloc,
+ .buf_free = bc_free,
+ .send_request = bc_send_request,
+ .set_retrans_timeout = xprt_set_retrans_timeout_def,
+ .close = bc_close,
+ .destroy = bc_destroy,
+ .print_stats = xs_tcp_print_stats,
+};
+
static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
unsigned int slot_table_size)
{