summaryrefslogtreecommitdiff
path: root/fs/smb/client/transport.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/smb/client/transport.c')
-rw-r--r--fs/smb/client/transport.c1810
1 files changed, 1810 insertions, 0 deletions
diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c
new file mode 100644
index 000000000000..0474d0bba0a2
--- /dev/null
+++ b/fs/smb/client/transport.c
@@ -0,0 +1,1810 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ *
+ * Copyright (C) International Business Machines Corp., 2002,2008
+ * Author(s): Steve French (sfrench@us.ibm.com)
+ * Jeremy Allison (jra@samba.org) 2006.
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/gfp.h>
+#include <linux/wait.h>
+#include <linux/net.h>
+#include <linux/delay.h>
+#include <linux/freezer.h>
+#include <linux/tcp.h>
+#include <linux/bvec.h>
+#include <linux/highmem.h>
+#include <linux/uaccess.h>
+#include <asm/processor.h>
+#include <linux/mempool.h>
+#include <linux/sched/signal.h>
+#include <linux/task_io_accounting_ops.h>
+#include "cifspdu.h"
+#include "cifsglob.h"
+#include "cifsproto.h"
+#include "cifs_debug.h"
+#include "smb2proto.h"
+#include "smbdirect.h"
+
+/* Max number of iovectors we can use off the stack when sending requests. */
+#define CIFS_MAX_IOV_SIZE 8
+
+void
+cifs_wake_up_task(struct mid_q_entry *mid)
+{
+ wake_up_process(mid->callback_data);
+}
+
+static struct mid_q_entry *
+alloc_mid(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
+{
+ struct mid_q_entry *temp;
+
+ if (server == NULL) {
+ cifs_dbg(VFS, "%s: null TCP session\n", __func__);
+ return NULL;
+ }
+
+ temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
+ memset(temp, 0, sizeof(struct mid_q_entry));
+ kref_init(&temp->refcount);
+ temp->mid = get_mid(smb_buffer);
+ temp->pid = current->pid;
+ temp->command = cpu_to_le16(smb_buffer->Command);
+ cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
+ /* easier to use jiffies */
+ /* when mid allocated can be before when sent */
+ temp->when_alloc = jiffies;
+ temp->server = server;
+
+ /*
+ * The default is for the mid to be synchronous, so the
+ * default callback just wakes up the current task.
+ */
+ get_task_struct(current);
+ temp->creator = current;
+ temp->callback = cifs_wake_up_task;
+ temp->callback_data = current;
+
+ atomic_inc(&mid_count);
+ temp->mid_state = MID_REQUEST_ALLOCATED;
+ return temp;
+}
+
+static void __release_mid(struct kref *refcount)
+{
+ struct mid_q_entry *midEntry =
+ container_of(refcount, struct mid_q_entry, refcount);
+#ifdef CONFIG_CIFS_STATS2
+ __le16 command = midEntry->server->vals->lock_cmd;
+ __u16 smb_cmd = le16_to_cpu(midEntry->command);
+ unsigned long now;
+ unsigned long roundtrip_time;
+#endif
+ struct TCP_Server_Info *server = midEntry->server;
+
+ if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
+ midEntry->mid_state == MID_RESPONSE_RECEIVED &&
+ server->ops->handle_cancelled_mid)
+ server->ops->handle_cancelled_mid(midEntry, server);
+
+ midEntry->mid_state = MID_FREE;
+ atomic_dec(&mid_count);
+ if (midEntry->large_buf)
+ cifs_buf_release(midEntry->resp_buf);
+ else
+ cifs_small_buf_release(midEntry->resp_buf);
+#ifdef CONFIG_CIFS_STATS2
+ now = jiffies;
+ if (now < midEntry->when_alloc)
+ cifs_server_dbg(VFS, "Invalid mid allocation time\n");
+ roundtrip_time = now - midEntry->when_alloc;
+
+ if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
+ if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
+ server->slowest_cmd[smb_cmd] = roundtrip_time;
+ server->fastest_cmd[smb_cmd] = roundtrip_time;
+ } else {
+ if (server->slowest_cmd[smb_cmd] < roundtrip_time)
+ server->slowest_cmd[smb_cmd] = roundtrip_time;
+ else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
+ server->fastest_cmd[smb_cmd] = roundtrip_time;
+ }
+ cifs_stats_inc(&server->num_cmds[smb_cmd]);
+ server->time_per_cmd[smb_cmd] += roundtrip_time;
+ }
+ /*
+ * commands taking longer than one second (default) can be indications
+ * that something is wrong, unless it is quite a slow link or a very
+ * busy server. Note that this calc is unlikely or impossible to wrap
+ * as long as slow_rsp_threshold is not set way above recommended max
+ * value (32767 ie 9 hours) and is generally harmless even if wrong
+ * since only affects debug counters - so leaving the calc as simple
+ * comparison rather than doing multiple conversions and overflow
+ * checks
+ */
+ if ((slow_rsp_threshold != 0) &&
+ time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
+ (midEntry->command != command)) {
+ /*
+ * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
+ * NB: le16_to_cpu returns unsigned so can not be negative below
+ */
+ if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
+ cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
+
+ trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
+ midEntry->when_sent, midEntry->when_received);
+ if (cifsFYI & CIFS_TIMER) {
+ pr_debug("slow rsp: cmd %d mid %llu",
+ midEntry->command, midEntry->mid);
+ cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
+ now - midEntry->when_alloc,
+ now - midEntry->when_sent,
+ now - midEntry->when_received);
+ }
+ }
+#endif
+ put_task_struct(midEntry->creator);
+
+ mempool_free(midEntry, cifs_mid_poolp);
+}
+
+void release_mid(struct mid_q_entry *mid)
+{
+ struct TCP_Server_Info *server = mid->server;
+
+ spin_lock(&server->mid_lock);
+ kref_put(&mid->refcount, __release_mid);
+ spin_unlock(&server->mid_lock);
+}
+
+void
+delete_mid(struct mid_q_entry *mid)
+{
+ spin_lock(&mid->server->mid_lock);
+ if (!(mid->mid_flags & MID_DELETED)) {
+ list_del_init(&mid->qhead);
+ mid->mid_flags |= MID_DELETED;
+ }
+ spin_unlock(&mid->server->mid_lock);
+
+ release_mid(mid);
+}
+
+/*
+ * smb_send_kvec - send an array of kvecs to the server
+ * @server: Server to send the data to
+ * @smb_msg: Message to send
+ * @sent: amount of data sent on socket is stored here
+ *
+ * Our basic "send data to server" function. Should be called with srv_mutex
+ * held. The caller is responsible for handling the results.
+ */
+static int
+smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
+ size_t *sent)
+{
+ int rc = 0;
+ int retries = 0;
+ struct socket *ssocket = server->ssocket;
+
+ *sent = 0;
+
+ if (server->noblocksnd)
+ smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
+ else
+ smb_msg->msg_flags = MSG_NOSIGNAL;
+
+ while (msg_data_left(smb_msg)) {
+ /*
+ * If blocking send, we try 3 times, since each can block
+ * for 5 seconds. For nonblocking we have to try more
+ * but wait increasing amounts of time allowing time for
+ * socket to clear. The overall time we wait in either
+ * case to send on the socket is about 15 seconds.
+ * Similarly we wait for 15 seconds for a response from
+ * the server in SendReceive[2] for the server to send
+ * a response back for most types of requests (except
+ * SMB Write past end of file which can be slow, and
+ * blocking lock operations). NFS waits slightly longer
+ * than CIFS, but this can make it take longer for
+ * nonresponsive servers to be detected and 15 seconds
+ * is more than enough time for modern networks to
+ * send a packet. In most cases if we fail to send
+ * after the retries we will kill the socket and
+ * reconnect which may clear the network problem.
+ */
+ rc = sock_sendmsg(ssocket, smb_msg);
+ if (rc == -EAGAIN) {
+ retries++;
+ if (retries >= 14 ||
+ (!server->noblocksnd && (retries > 2))) {
+ cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
+ ssocket);
+ return -EAGAIN;
+ }
+ msleep(1 << retries);
+ continue;
+ }
+
+ if (rc < 0)
+ return rc;
+
+ if (rc == 0) {
+ /* should never happen, letting socket clear before
+ retrying is our only obvious option here */
+ cifs_server_dbg(VFS, "tcp sent no data\n");
+ msleep(500);
+ continue;
+ }
+
+ /* send was at least partially successful */
+ *sent += rc;
+ retries = 0; /* in case we get ENOSPC on the next send */
+ }
+ return 0;
+}
+
+unsigned long
+smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
+{
+ unsigned int i;
+ struct kvec *iov;
+ int nvec;
+ unsigned long buflen = 0;
+
+ if (!is_smb1(server) && rqst->rq_nvec >= 2 &&
+ rqst->rq_iov[0].iov_len == 4) {
+ iov = &rqst->rq_iov[1];
+ nvec = rqst->rq_nvec - 1;
+ } else {
+ iov = rqst->rq_iov;
+ nvec = rqst->rq_nvec;
+ }
+
+ /* total up iov array first */
+ for (i = 0; i < nvec; i++)
+ buflen += iov[i].iov_len;
+
+ buflen += iov_iter_count(&rqst->rq_iter);
+ return buflen;
+}
+
+static int
+__smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
+ struct smb_rqst *rqst)
+{
+ int rc;
+ struct kvec *iov;
+ int n_vec;
+ unsigned int send_length = 0;
+ unsigned int i, j;
+ sigset_t mask, oldmask;
+ size_t total_len = 0, sent, size;
+ struct socket *ssocket = server->ssocket;
+ struct msghdr smb_msg = {};
+ __be32 rfc1002_marker;
+
+ cifs_in_send_inc(server);
+ if (cifs_rdma_enabled(server)) {
+ /* return -EAGAIN when connecting or reconnecting */
+ rc = -EAGAIN;
+ if (server->smbd_conn)
+ rc = smbd_send(server, num_rqst, rqst);
+ goto smbd_done;
+ }
+
+ rc = -EAGAIN;
+ if (ssocket == NULL)
+ goto out;
+
+ rc = -ERESTARTSYS;
+ if (fatal_signal_pending(current)) {
+ cifs_dbg(FYI, "signal pending before send request\n");
+ goto out;
+ }
+
+ rc = 0;
+ /* cork the socket */
+ tcp_sock_set_cork(ssocket->sk, true);
+
+ for (j = 0; j < num_rqst; j++)
+ send_length += smb_rqst_len(server, &rqst[j]);
+ rfc1002_marker = cpu_to_be32(send_length);
+
+ /*
+ * We should not allow signals to interrupt the network send because
+ * any partial send will cause session reconnects thus increasing
+ * latency of system calls and overload a server with unnecessary
+ * requests.
+ */
+
+ sigfillset(&mask);
+ sigprocmask(SIG_BLOCK, &mask, &oldmask);
+
+ /* Generate a rfc1002 marker for SMB2+ */
+ if (!is_smb1(server)) {
+ struct kvec hiov = {
+ .iov_base = &rfc1002_marker,
+ .iov_len = 4
+ };
+ iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, &hiov, 1, 4);
+ rc = smb_send_kvec(server, &smb_msg, &sent);
+ if (rc < 0)
+ goto unmask;
+
+ total_len += sent;
+ send_length += 4;
+ }
+
+ cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
+
+ for (j = 0; j < num_rqst; j++) {
+ iov = rqst[j].rq_iov;
+ n_vec = rqst[j].rq_nvec;
+
+ size = 0;
+ for (i = 0; i < n_vec; i++) {
+ dump_smb(iov[i].iov_base, iov[i].iov_len);
+ size += iov[i].iov_len;
+ }
+
+ iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, iov, n_vec, size);
+
+ rc = smb_send_kvec(server, &smb_msg, &sent);
+ if (rc < 0)
+ goto unmask;
+
+ total_len += sent;
+
+ if (iov_iter_count(&rqst[j].rq_iter) > 0) {
+ smb_msg.msg_iter = rqst[j].rq_iter;
+ rc = smb_send_kvec(server, &smb_msg, &sent);
+ if (rc < 0)
+ break;
+ total_len += sent;
+ }
+
+}
+
+unmask:
+ sigprocmask(SIG_SETMASK, &oldmask, NULL);
+
+ /*
+ * If signal is pending but we have already sent the whole packet to
+ * the server we need to return success status to allow a corresponding
+ * mid entry to be kept in the pending requests queue thus allowing
+ * to handle responses from the server by the client.
+ *
+ * If only part of the packet has been sent there is no need to hide
+ * interrupt because the session will be reconnected anyway, so there
+ * won't be any response from the server to handle.
+ */
+
+ if (signal_pending(current) && (total_len != send_length)) {
+ cifs_dbg(FYI, "signal is pending after attempt to send\n");
+ rc = -ERESTARTSYS;
+ }
+
+ /* uncork it */
+ tcp_sock_set_cork(ssocket->sk, false);
+
+ if ((total_len > 0) && (total_len != send_length)) {
+ cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
+ send_length, total_len);
+ /*
+ * If we have only sent part of an SMB then the next SMB could
+ * be taken as the remainder of this one. We need to kill the
+ * socket so the server throws away the partial SMB
+ */
+ cifs_signal_cifsd_for_reconnect(server, false);
+ trace_smb3_partial_send_reconnect(server->CurrentMid,
+ server->conn_id, server->hostname);
+ }
+smbd_done:
+ if (rc < 0 && rc != -EINTR)
+ cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
+ rc);
+ else if (rc > 0)
+ rc = 0;
+out:
+ cifs_in_send_dec(server);
+ return rc;
+}
+
+static int
+smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
+ struct smb_rqst *rqst, int flags)
+{
+ struct kvec iov;
+ struct smb2_transform_hdr *tr_hdr;
+ struct smb_rqst cur_rqst[MAX_COMPOUND];
+ int rc;
+
+ if (!(flags & CIFS_TRANSFORM_REQ))
+ return __smb_send_rqst(server, num_rqst, rqst);
+
+ if (num_rqst > MAX_COMPOUND - 1)
+ return -ENOMEM;
+
+ if (!server->ops->init_transform_rq) {
+ cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
+ return -EIO;
+ }
+
+ tr_hdr = kzalloc(sizeof(*tr_hdr), GFP_NOFS);
+ if (!tr_hdr)
+ return -ENOMEM;
+
+ memset(&cur_rqst[0], 0, sizeof(cur_rqst));
+ memset(&iov, 0, sizeof(iov));
+
+ iov.iov_base = tr_hdr;
+ iov.iov_len = sizeof(*tr_hdr);
+ cur_rqst[0].rq_iov = &iov;
+ cur_rqst[0].rq_nvec = 1;
+
+ rc = server->ops->init_transform_rq(server, num_rqst + 1,
+ &cur_rqst[0], rqst);
+ if (rc)
+ goto out;
+
+ rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
+ smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
+out:
+ kfree(tr_hdr);
+ return rc;
+}
+
+int
+smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
+ unsigned int smb_buf_length)
+{
+ struct kvec iov[2];
+ struct smb_rqst rqst = { .rq_iov = iov,
+ .rq_nvec = 2 };
+
+ iov[0].iov_base = smb_buffer;
+ iov[0].iov_len = 4;
+ iov[1].iov_base = (char *)smb_buffer + 4;
+ iov[1].iov_len = smb_buf_length;
+
+ return __smb_send_rqst(server, 1, &rqst);
+}
+
+static int
+wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
+ const int timeout, const int flags,
+ unsigned int *instance)
+{
+ long rc;
+ int *credits;
+ int optype;
+ long int t;
+ int scredits, in_flight;
+
+ if (timeout < 0)
+ t = MAX_JIFFY_OFFSET;
+ else
+ t = msecs_to_jiffies(timeout);
+
+ optype = flags & CIFS_OP_MASK;
+
+ *instance = 0;
+
+ credits = server->ops->get_credits_field(server, optype);
+ /* Since an echo is already inflight, no need to wait to send another */
+ if (*credits <= 0 && optype == CIFS_ECHO_OP)
+ return -EAGAIN;
+
+ spin_lock(&server->req_lock);
+ if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
+ /* oplock breaks must not be held up */
+ server->in_flight++;
+ if (server->in_flight > server->max_in_flight)
+ server->max_in_flight = server->in_flight;
+ *credits -= 1;
+ *instance = server->reconnect_instance;
+ scredits = *credits;
+ in_flight = server->in_flight;
+ spin_unlock(&server->req_lock);
+
+ trace_smb3_nblk_credits(server->CurrentMid,
+ server->conn_id, server->hostname, scredits, -1, in_flight);
+ cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
+ __func__, 1, scredits);
+
+ return 0;
+ }
+
+ while (1) {
+ if (*credits < num_credits) {
+ scredits = *credits;
+ spin_unlock(&server->req_lock);
+
+ cifs_num_waiters_inc(server);
+ rc = wait_event_killable_timeout(server->request_q,
+ has_credits(server, credits, num_credits), t);
+ cifs_num_waiters_dec(server);
+ if (!rc) {
+ spin_lock(&server->req_lock);
+ scredits = *credits;
+ in_flight = server->in_flight;
+ spin_unlock(&server->req_lock);
+
+ trace_smb3_credit_timeout(server->CurrentMid,
+ server->conn_id, server->hostname, scredits,
+ num_credits, in_flight);
+ cifs_server_dbg(VFS, "wait timed out after %d ms\n",
+ timeout);
+ return -EBUSY;
+ }
+ if (rc == -ERESTARTSYS)
+ return -ERESTARTSYS;
+ spin_lock(&server->req_lock);
+ } else {
+ spin_unlock(&server->req_lock);
+
+ spin_lock(&server->srv_lock);
+ if (server->tcpStatus == CifsExiting) {
+ spin_unlock(&server->srv_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&server->srv_lock);
+
+ /*
+ * For normal commands, reserve the last MAX_COMPOUND
+ * credits to compound requests.
+ * Otherwise these compounds could be permanently
+ * starved for credits by single-credit requests.
+ *
+ * To prevent spinning CPU, block this thread until
+ * there are >MAX_COMPOUND credits available.
+ * But only do this is we already have a lot of
+ * credits in flight to avoid triggering this check
+ * for servers that are slow to hand out credits on
+ * new sessions.
+ */
+ spin_lock(&server->req_lock);
+ if (!optype && num_credits == 1 &&
+ server->in_flight > 2 * MAX_COMPOUND &&
+ *credits <= MAX_COMPOUND) {
+ spin_unlock(&server->req_lock);
+
+ cifs_num_waiters_inc(server);
+ rc = wait_event_killable_timeout(
+ server->request_q,
+ has_credits(server, credits,
+ MAX_COMPOUND + 1),
+ t);
+ cifs_num_waiters_dec(server);
+ if (!rc) {
+ spin_lock(&server->req_lock);
+ scredits = *credits;
+ in_flight = server->in_flight;
+ spin_unlock(&server->req_lock);
+
+ trace_smb3_credit_timeout(
+ server->CurrentMid,
+ server->conn_id, server->hostname,
+ scredits, num_credits, in_flight);
+ cifs_server_dbg(VFS, "wait timed out after %d ms\n",
+ timeout);
+ return -EBUSY;
+ }
+ if (rc == -ERESTARTSYS)
+ return -ERESTARTSYS;
+ spin_lock(&server->req_lock);
+ continue;
+ }
+
+ /*
+ * Can not count locking commands against total
+ * as they are allowed to block on server.
+ */
+
+ /* update # of requests on the wire to server */
+ if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
+ *credits -= num_credits;
+ server->in_flight += num_credits;
+ if (server->in_flight > server->max_in_flight)
+ server->max_in_flight = server->in_flight;
+ *instance = server->reconnect_instance;
+ }
+ scredits = *credits;
+ in_flight = server->in_flight;
+ spin_unlock(&server->req_lock);
+
+ trace_smb3_waitff_credits(server->CurrentMid,
+ server->conn_id, server->hostname, scredits,
+ -(num_credits), in_flight);
+ cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
+ __func__, num_credits, scredits);
+ break;
+ }
+ }
+ return 0;
+}
+
+static int
+wait_for_free_request(struct TCP_Server_Info *server, const int flags,
+ unsigned int *instance)
+{
+ return wait_for_free_credits(server, 1, -1, flags,
+ instance);
+}
+
+static int
+wait_for_compound_request(struct TCP_Server_Info *server, int num,
+ const int flags, unsigned int *instance)
+{
+ int *credits;
+ int scredits, in_flight;
+
+ credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
+
+ spin_lock(&server->req_lock);
+ scredits = *credits;
+ in_flight = server->in_flight;
+
+ if (*credits < num) {
+ /*
+ * If the server is tight on resources or just gives us less
+ * credits for other reasons (e.g. requests are coming out of
+ * order and the server delays granting more credits until it
+ * processes a missing mid) and we exhausted most available
+ * credits there may be situations when we try to send
+ * a compound request but we don't have enough credits. At this
+ * point the client needs to decide if it should wait for
+ * additional credits or fail the request. If at least one
+ * request is in flight there is a high probability that the
+ * server will return enough credits to satisfy this compound
+ * request.
+ *
+ * Return immediately if no requests in flight since we will be
+ * stuck on waiting for credits.
+ */
+ if (server->in_flight == 0) {
+ spin_unlock(&server->req_lock);
+ trace_smb3_insufficient_credits(server->CurrentMid,
+ server->conn_id, server->hostname, scredits,
+ num, in_flight);
+ cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
+ __func__, in_flight, num, scredits);
+ return -EDEADLK;
+ }
+ }
+ spin_unlock(&server->req_lock);
+
+ return wait_for_free_credits(server, num, 60000, flags,
+ instance);
+}
+
+int
+cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
+ unsigned int *num, struct cifs_credits *credits)
+{
+ *num = size;
+ credits->value = 0;
+ credits->instance = server->reconnect_instance;
+ return 0;
+}
+
+static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
+ struct mid_q_entry **ppmidQ)
+{
+ spin_lock(&ses->ses_lock);
+ if (ses->ses_status == SES_NEW) {
+ if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
+ (in_buf->Command != SMB_COM_NEGOTIATE)) {
+ spin_unlock(&ses->ses_lock);
+ return -EAGAIN;
+ }
+ /* else ok - we are setting up session */
+ }
+
+ if (ses->ses_status == SES_EXITING) {
+ /* check if SMB session is bad because we are setting it up */
+ if (in_buf->Command != SMB_COM_LOGOFF_ANDX) {
+ spin_unlock(&ses->ses_lock);
+ return -EAGAIN;
+ }
+ /* else ok - we are shutting down session */
+ }
+ spin_unlock(&ses->ses_lock);
+
+ *ppmidQ = alloc_mid(in_buf, ses->server);
+ if (*ppmidQ == NULL)
+ return -ENOMEM;
+ spin_lock(&ses->server->mid_lock);
+ list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
+ spin_unlock(&ses->server->mid_lock);
+ return 0;
+}
+
+static int
+wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
+{
+ int error;
+
+ error = wait_event_state(server->response_q,
+ midQ->mid_state != MID_REQUEST_SUBMITTED,
+ (TASK_KILLABLE|TASK_FREEZABLE_UNSAFE));
+ if (error < 0)
+ return -ERESTARTSYS;
+
+ return 0;
+}
+
+struct mid_q_entry *
+cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
+{
+ int rc;
+ struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
+ struct mid_q_entry *mid;
+
+ if (rqst->rq_iov[0].iov_len != 4 ||
+ rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
+ return ERR_PTR(-EIO);
+
+ /* enable signing if server requires it */
+ if (server->sign)
+ hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
+
+ mid = alloc_mid(hdr, server);
+ if (mid == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
+ if (rc) {
+ release_mid(mid);
+ return ERR_PTR(rc);
+ }
+
+ return mid;
+}
+
+/*
+ * Send a SMB request and set the callback function in the mid to handle
+ * the result. Caller is responsible for dealing with timeouts.
+ */
+int
+cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
+ mid_receive_t *receive, mid_callback_t *callback,
+ mid_handle_t *handle, void *cbdata, const int flags,
+ const struct cifs_credits *exist_credits)
+{
+ int rc;
+ struct mid_q_entry *mid;
+ struct cifs_credits credits = { .value = 0, .instance = 0 };
+ unsigned int instance;
+ int optype;
+
+ optype = flags & CIFS_OP_MASK;
+
+ if ((flags & CIFS_HAS_CREDITS) == 0) {
+ rc = wait_for_free_request(server, flags, &instance);
+ if (rc)
+ return rc;
+ credits.value = 1;
+ credits.instance = instance;
+ } else
+ instance = exist_credits->instance;
+
+ cifs_server_lock(server);
+
+ /*
+ * We can't use credits obtained from the previous session to send this
+ * request. Check if there were reconnects after we obtained credits and
+ * return -EAGAIN in such cases to let callers handle it.
+ */
+ if (instance != server->reconnect_instance) {
+ cifs_server_unlock(server);
+ add_credits_and_wake_if(server, &credits, optype);
+ return -EAGAIN;
+ }
+
+ mid = server->ops->setup_async_request(server, rqst);
+ if (IS_ERR(mid)) {
+ cifs_server_unlock(server);
+ add_credits_and_wake_if(server, &credits, optype);
+ return PTR_ERR(mid);
+ }
+
+ mid->receive = receive;
+ mid->callback = callback;
+ mid->callback_data = cbdata;
+ mid->handle = handle;
+ mid->mid_state = MID_REQUEST_SUBMITTED;
+
+ /* put it on the pending_mid_q */
+ spin_lock(&server->mid_lock);
+ list_add_tail(&mid->qhead, &server->pending_mid_q);
+ spin_unlock(&server->mid_lock);
+
+ /*
+ * Need to store the time in mid before calling I/O. For call_async,
+ * I/O response may come back and free the mid entry on another thread.
+ */
+ cifs_save_when_sent(mid);
+ rc = smb_send_rqst(server, 1, rqst, flags);
+
+ if (rc < 0) {
+ revert_current_mid(server, mid->credits);
+ server->sequence_number -= 2;
+ delete_mid(mid);
+ }
+
+ cifs_server_unlock(server);
+
+ if (rc == 0)
+ return 0;
+
+ add_credits_and_wake_if(server, &credits, optype);
+ return rc;
+}
+
+/*
+ *
+ * Send an SMB Request. No response info (other than return code)
+ * needs to be parsed.
+ *
+ * flags indicate the type of request buffer and how long to wait
+ * and whether to log NT STATUS code (error) before mapping it to POSIX error
+ *
+ */
+int
+SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
+ char *in_buf, int flags)
+{
+ int rc;
+ struct kvec iov[1];
+ struct kvec rsp_iov;
+ int resp_buf_type;
+
+ iov[0].iov_base = in_buf;
+ iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
+ flags |= CIFS_NO_RSP_BUF;
+ rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
+ cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
+
+ return rc;
+}
+
+static int
+cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
+{
+ int rc = 0;
+
+ cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
+ __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
+
+ spin_lock(&server->mid_lock);
+ switch (mid->mid_state) {
+ case MID_RESPONSE_RECEIVED:
+ spin_unlock(&server->mid_lock);
+ return rc;
+ case MID_RETRY_NEEDED:
+ rc = -EAGAIN;
+ break;
+ case MID_RESPONSE_MALFORMED:
+ rc = -EIO;
+ break;
+ case MID_SHUTDOWN:
+ rc = -EHOSTDOWN;
+ break;
+ default:
+ if (!(mid->mid_flags & MID_DELETED)) {
+ list_del_init(&mid->qhead);
+ mid->mid_flags |= MID_DELETED;
+ }
+ cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
+ __func__, mid->mid, mid->mid_state);
+ rc = -EIO;
+ }
+ spin_unlock(&server->mid_lock);
+
+ release_mid(mid);
+ return rc;
+}
+
+static inline int
+send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
+ struct mid_q_entry *mid)
+{
+ return server->ops->send_cancel ?
+ server->ops->send_cancel(server, rqst, mid) : 0;
+}
+
+int
+cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
+ bool log_error)
+{
+ unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
+
+ dump_smb(mid->resp_buf, min_t(u32, 92, len));
+
+ /* convert the length into a more usable form */
+ if (server->sign) {
+ struct kvec iov[2];
+ int rc = 0;
+ struct smb_rqst rqst = { .rq_iov = iov,
+ .rq_nvec = 2 };
+
+ iov[0].iov_base = mid->resp_buf;
+ iov[0].iov_len = 4;
+ iov[1].iov_base = (char *)mid->resp_buf + 4;
+ iov[1].iov_len = len - 4;
+ /* FIXME: add code to kill session */
+ rc = cifs_verify_signature(&rqst, server,
+ mid->sequence_number);
+ if (rc)
+ cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
+ rc);
+ }
+
+ /* BB special case reconnect tid and uid here? */
+ return map_and_check_smb_error(mid, log_error);
+}
+
+struct mid_q_entry *
+cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
+ struct smb_rqst *rqst)
+{
+ int rc;
+ struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
+ struct mid_q_entry *mid;
+
+ if (rqst->rq_iov[0].iov_len != 4 ||
+ rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
+ return ERR_PTR(-EIO);
+
+ rc = allocate_mid(ses, hdr, &mid);
+ if (rc)
+ return ERR_PTR(rc);
+ rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
+ if (rc) {
+ delete_mid(mid);
+ return ERR_PTR(rc);
+ }
+ return mid;
+}
+
+static void
+cifs_compound_callback(struct mid_q_entry *mid)
+{
+ struct TCP_Server_Info *server = mid->server;
+ struct cifs_credits credits;
+
+ credits.value = server->ops->get_credits(mid);
+ credits.instance = server->reconnect_instance;
+
+ add_credits(server, &credits, mid->optype);
+}
+
+static void
+cifs_compound_last_callback(struct mid_q_entry *mid)
+{
+ cifs_compound_callback(mid);
+ cifs_wake_up_task(mid);
+}
+
+static void
+cifs_cancelled_callback(struct mid_q_entry *mid)
+{
+ cifs_compound_callback(mid);
+ release_mid(mid);
+}
+
+/*
+ * Return a channel (master if none) of @ses that can be used to send
+ * regular requests.
+ *
+ * If we are currently binding a new channel (negprot/sess.setup),
+ * return the new incomplete channel.
+ */
+struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
+{
+ uint index = 0;
+ unsigned int min_in_flight = UINT_MAX, max_in_flight = 0;
+ struct TCP_Server_Info *server = NULL;
+ int i;
+
+ if (!ses)
+ return NULL;
+
+ spin_lock(&ses->chan_lock);
+ for (i = 0; i < ses->chan_count; i++) {
+ server = ses->chans[i].server;
+ if (!server)
+ continue;
+
+ /*
+ * strictly speaking, we should pick up req_lock to read
+ * server->in_flight. But it shouldn't matter much here if we
+ * race while reading this data. The worst that can happen is
+ * that we could use a channel that's not least loaded. Avoiding
+ * taking the lock could help reduce wait time, which is
+ * important for this function
+ */
+ if (server->in_flight < min_in_flight) {
+ min_in_flight = server->in_flight;
+ index = i;
+ }
+ if (server->in_flight > max_in_flight)
+ max_in_flight = server->in_flight;
+ }
+
+ /* if all channels are equally loaded, fall back to round-robin */
+ if (min_in_flight == max_in_flight) {
+ index = (uint)atomic_inc_return(&ses->chan_seq);
+ index %= ses->chan_count;
+ }
+ spin_unlock(&ses->chan_lock);
+
+ return ses->chans[index].server;
+}
+
+int
+compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
+ struct TCP_Server_Info *server,
+ const int flags, const int num_rqst, struct smb_rqst *rqst,
+ int *resp_buf_type, struct kvec *resp_iov)
+{
+ int i, j, optype, rc = 0;
+ struct mid_q_entry *midQ[MAX_COMPOUND];
+ bool cancelled_mid[MAX_COMPOUND] = {false};
+ struct cifs_credits credits[MAX_COMPOUND] = {
+ { .value = 0, .instance = 0 }
+ };
+ unsigned int instance;
+ char *buf;
+
+ optype = flags & CIFS_OP_MASK;
+
+ for (i = 0; i < num_rqst; i++)
+ resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
+
+ if (!ses || !ses->server || !server) {
+ cifs_dbg(VFS, "Null session\n");
+ return -EIO;
+ }
+
+ spin_lock(&server->srv_lock);
+ if (server->tcpStatus == CifsExiting) {
+ spin_unlock(&server->srv_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&server->srv_lock);
+
+ /*
+ * Wait for all the requests to become available.
+ * This approach still leaves the possibility to be stuck waiting for
+ * credits if the server doesn't grant credits to the outstanding
+ * requests and if the client is completely idle, not generating any
+ * other requests.
+ * This can be handled by the eventual session reconnect.
+ */
+ rc = wait_for_compound_request(server, num_rqst, flags,
+ &instance);
+ if (rc)
+ return rc;
+
+ for (i = 0; i < num_rqst; i++) {
+ credits[i].value = 1;
+ credits[i].instance = instance;
+ }
+
+ /*
+ * Make sure that we sign in the same order that we send on this socket
+ * and avoid races inside tcp sendmsg code that could cause corruption
+ * of smb data.
+ */
+
+ cifs_server_lock(server);
+
+ /*
+ * All the parts of the compound chain belong obtained credits from the
+ * same session. We can not use credits obtained from the previous
+ * session to send this request. Check if there were reconnects after
+ * we obtained credits and return -EAGAIN in such cases to let callers
+ * handle it.
+ */
+ if (instance != server->reconnect_instance) {
+ cifs_server_unlock(server);
+ for (j = 0; j < num_rqst; j++)
+ add_credits(server, &credits[j], optype);
+ return -EAGAIN;
+ }
+
+ for (i = 0; i < num_rqst; i++) {
+ midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
+ if (IS_ERR(midQ[i])) {
+ revert_current_mid(server, i);
+ for (j = 0; j < i; j++)
+ delete_mid(midQ[j]);
+ cifs_server_unlock(server);
+
+ /* Update # of requests on wire to server */
+ for (j = 0; j < num_rqst; j++)
+ add_credits(server, &credits[j], optype);
+ return PTR_ERR(midQ[i]);
+ }
+
+ midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
+ midQ[i]->optype = optype;
+ /*
+ * Invoke callback for every part of the compound chain
+ * to calculate credits properly. Wake up this thread only when
+ * the last element is received.
+ */
+ if (i < num_rqst - 1)
+ midQ[i]->callback = cifs_compound_callback;
+ else
+ midQ[i]->callback = cifs_compound_last_callback;
+ }
+ rc = smb_send_rqst(server, num_rqst, rqst, flags);
+
+ for (i = 0; i < num_rqst; i++)
+ cifs_save_when_sent(midQ[i]);
+
+ if (rc < 0) {
+ revert_current_mid(server, num_rqst);
+ server->sequence_number -= 2;
+ }
+
+ cifs_server_unlock(server);
+
+ /*
+ * If sending failed for some reason or it is an oplock break that we
+ * will not receive a response to - return credits back
+ */
+ if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
+ for (i = 0; i < num_rqst; i++)
+ add_credits(server, &credits[i], optype);
+ goto out;
+ }
+
+ /*
+ * At this point the request is passed to the network stack - we assume
+ * that any credits taken from the server structure on the client have
+ * been spent and we can't return them back. Once we receive responses
+ * we will collect credits granted by the server in the mid callbacks
+ * and add those credits to the server structure.
+ */
+
+ /*
+ * Compounding is never used during session establish.
+ */
+ spin_lock(&ses->ses_lock);
+ if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
+ spin_unlock(&ses->ses_lock);
+
+ cifs_server_lock(server);
+ smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec);
+ cifs_server_unlock(server);
+
+ spin_lock(&ses->ses_lock);
+ }
+ spin_unlock(&ses->ses_lock);
+
+ for (i = 0; i < num_rqst; i++) {
+ rc = wait_for_response(server, midQ[i]);
+ if (rc != 0)
+ break;
+ }
+ if (rc != 0) {
+ for (; i < num_rqst; i++) {
+ cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
+ midQ[i]->mid, le16_to_cpu(midQ[i]->command));
+ send_cancel(server, &rqst[i], midQ[i]);
+ spin_lock(&server->mid_lock);
+ midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
+ if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
+ midQ[i]->callback = cifs_cancelled_callback;
+ cancelled_mid[i] = true;
+ credits[i].value = 0;
+ }
+ spin_unlock(&server->mid_lock);
+ }
+ }
+
+ for (i = 0; i < num_rqst; i++) {
+ if (rc < 0)
+ goto out;
+
+ rc = cifs_sync_mid_result(midQ[i], server);
+ if (rc != 0) {
+ /* mark this mid as cancelled to not free it below */
+ cancelled_mid[i] = true;
+ goto out;
+ }
+
+ if (!midQ[i]->resp_buf ||
+ midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
+ rc = -EIO;
+ cifs_dbg(FYI, "Bad MID state?\n");
+ goto out;
+ }
+
+ buf = (char *)midQ[i]->resp_buf;
+ resp_iov[i].iov_base = buf;
+ resp_iov[i].iov_len = midQ[i]->resp_buf_size +
+ HEADER_PREAMBLE_SIZE(server);
+
+ if (midQ[i]->large_buf)
+ resp_buf_type[i] = CIFS_LARGE_BUFFER;
+ else
+ resp_buf_type[i] = CIFS_SMALL_BUFFER;
+
+ rc = server->ops->check_receive(midQ[i], server,
+ flags & CIFS_LOG_ERROR);
+
+ /* mark it so buf will not be freed by delete_mid */
+ if ((flags & CIFS_NO_RSP_BUF) == 0)
+ midQ[i]->resp_buf = NULL;
+
+ }
+
+ /*
+ * Compounding is never used during session establish.
+ */
+ spin_lock(&ses->ses_lock);
+ if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
+ struct kvec iov = {
+ .iov_base = resp_iov[0].iov_base,
+ .iov_len = resp_iov[0].iov_len
+ };
+ spin_unlock(&ses->ses_lock);
+ cifs_server_lock(server);
+ smb311_update_preauth_hash(ses, server, &iov, 1);
+ cifs_server_unlock(server);
+ spin_lock(&ses->ses_lock);
+ }
+ spin_unlock(&ses->ses_lock);
+
+out:
+ /*
+ * This will dequeue all mids. After this it is important that the
+ * demultiplex_thread will not process any of these mids any futher.
+ * This is prevented above by using a noop callback that will not
+ * wake this thread except for the very last PDU.
+ */
+ for (i = 0; i < num_rqst; i++) {
+ if (!cancelled_mid[i])
+ delete_mid(midQ[i]);
+ }
+
+ return rc;
+}
+
+int
+cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
+ struct TCP_Server_Info *server,
+ struct smb_rqst *rqst, int *resp_buf_type, const int flags,
+ struct kvec *resp_iov)
+{
+ return compound_send_recv(xid, ses, server, flags, 1,
+ rqst, resp_buf_type, resp_iov);
+}
+
+int
+SendReceive2(const unsigned int xid, struct cifs_ses *ses,
+ struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
+ const int flags, struct kvec *resp_iov)
+{
+ struct smb_rqst rqst;
+ struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
+ int rc;
+
+ if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
+ new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
+ GFP_KERNEL);
+ if (!new_iov) {
+ /* otherwise cifs_send_recv below sets resp_buf_type */
+ *resp_buf_type = CIFS_NO_BUFFER;
+ return -ENOMEM;
+ }
+ } else
+ new_iov = s_iov;
+
+ /* 1st iov is a RFC1001 length followed by the rest of the packet */
+ memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
+
+ new_iov[0].iov_base = new_iov[1].iov_base;
+ new_iov[0].iov_len = 4;
+ new_iov[1].iov_base += 4;
+ new_iov[1].iov_len -= 4;
+
+ memset(&rqst, 0, sizeof(struct smb_rqst));
+ rqst.rq_iov = new_iov;
+ rqst.rq_nvec = n_vec + 1;
+
+ rc = cifs_send_recv(xid, ses, ses->server,
+ &rqst, resp_buf_type, flags, resp_iov);
+ if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
+ kfree(new_iov);
+ return rc;
+}
+
+int
+SendReceive(const unsigned int xid, struct cifs_ses *ses,
+ struct smb_hdr *in_buf, struct smb_hdr *out_buf,
+ int *pbytes_returned, const int flags)
+{
+ int rc = 0;
+ struct mid_q_entry *midQ;
+ unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
+ struct kvec iov = { .iov_base = in_buf, .iov_len = len };
+ struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
+ struct cifs_credits credits = { .value = 1, .instance = 0 };
+ struct TCP_Server_Info *server;
+
+ if (ses == NULL) {
+ cifs_dbg(VFS, "Null smb session\n");
+ return -EIO;
+ }
+ server = ses->server;
+ if (server == NULL) {
+ cifs_dbg(VFS, "Null tcp session\n");
+ return -EIO;
+ }
+
+ spin_lock(&server->srv_lock);
+ if (server->tcpStatus == CifsExiting) {
+ spin_unlock(&server->srv_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&server->srv_lock);
+
+ /* Ensure that we do not send more than 50 overlapping requests
+ to the same server. We may make this configurable later or
+ use ses->maxReq */
+
+ if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
+ cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
+ len);
+ return -EIO;
+ }
+
+ rc = wait_for_free_request(server, flags, &credits.instance);
+ if (rc)
+ return rc;
+
+ /* make sure that we sign in the same order that we send on this socket
+ and avoid races inside tcp sendmsg code that could cause corruption
+ of smb data */
+
+ cifs_server_lock(server);
+
+ rc = allocate_mid(ses, in_buf, &midQ);
+ if (rc) {
+ cifs_server_unlock(server);
+ /* Update # of requests on wire to server */
+ add_credits(server, &credits, 0);
+ return rc;
+ }
+
+ rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
+ if (rc) {
+ cifs_server_unlock(server);
+ goto out;
+ }
+
+ midQ->mid_state = MID_REQUEST_SUBMITTED;
+
+ rc = smb_send(server, in_buf, len);
+ cifs_save_when_sent(midQ);
+
+ if (rc < 0)
+ server->sequence_number -= 2;
+
+ cifs_server_unlock(server);
+
+ if (rc < 0)
+ goto out;
+
+ rc = wait_for_response(server, midQ);
+ if (rc != 0) {
+ send_cancel(server, &rqst, midQ);
+ spin_lock(&server->mid_lock);
+ if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
+ /* no longer considered to be "in-flight" */
+ midQ->callback = release_mid;
+ spin_unlock(&server->mid_lock);
+ add_credits(server, &credits, 0);
+ return rc;
+ }
+ spin_unlock(&server->mid_lock);
+ }
+
+ rc = cifs_sync_mid_result(midQ, server);
+ if (rc != 0) {
+ add_credits(server, &credits, 0);
+ return rc;
+ }
+
+ if (!midQ->resp_buf || !out_buf ||
+ midQ->mid_state != MID_RESPONSE_RECEIVED) {
+ rc = -EIO;
+ cifs_server_dbg(VFS, "Bad MID state?\n");
+ goto out;
+ }
+
+ *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
+ memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
+ rc = cifs_check_receive(midQ, server, 0);
+out:
+ delete_mid(midQ);
+ add_credits(server, &credits, 0);
+
+ return rc;
+}
+
+/* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
+ blocking lock to return. */
+
+static int
+send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
+ struct smb_hdr *in_buf,
+ struct smb_hdr *out_buf)
+{
+ int bytes_returned;
+ struct cifs_ses *ses = tcon->ses;
+ LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
+
+ /* We just modify the current in_buf to change
+ the type of lock from LOCKING_ANDX_SHARED_LOCK
+ or LOCKING_ANDX_EXCLUSIVE_LOCK to
+ LOCKING_ANDX_CANCEL_LOCK. */
+
+ pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
+ pSMB->Timeout = 0;
+ pSMB->hdr.Mid = get_next_mid(ses->server);
+
+ return SendReceive(xid, ses, in_buf, out_buf,
+ &bytes_returned, 0);
+}
+
+int
+SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
+ struct smb_hdr *in_buf, struct smb_hdr *out_buf,
+ int *pbytes_returned)
+{
+ int rc = 0;
+ int rstart = 0;
+ struct mid_q_entry *midQ;
+ struct cifs_ses *ses;
+ unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
+ struct kvec iov = { .iov_base = in_buf, .iov_len = len };
+ struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
+ unsigned int instance;
+ struct TCP_Server_Info *server;
+
+ if (tcon == NULL || tcon->ses == NULL) {
+ cifs_dbg(VFS, "Null smb session\n");
+ return -EIO;
+ }
+ ses = tcon->ses;
+ server = ses->server;
+
+ if (server == NULL) {
+ cifs_dbg(VFS, "Null tcp session\n");
+ return -EIO;
+ }
+
+ spin_lock(&server->srv_lock);
+ if (server->tcpStatus == CifsExiting) {
+ spin_unlock(&server->srv_lock);
+ return -ENOENT;
+ }
+ spin_unlock(&server->srv_lock);
+
+ /* Ensure that we do not send more than 50 overlapping requests
+ to the same server. We may make this configurable later or
+ use ses->maxReq */
+
+ if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
+ cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
+ len);
+ return -EIO;
+ }
+
+ rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
+ if (rc)
+ return rc;
+
+ /* make sure that we sign in the same order that we send on this socket
+ and avoid races inside tcp sendmsg code that could cause corruption
+ of smb data */
+
+ cifs_server_lock(server);
+
+ rc = allocate_mid(ses, in_buf, &midQ);
+ if (rc) {
+ cifs_server_unlock(server);
+ return rc;
+ }
+
+ rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
+ if (rc) {
+ delete_mid(midQ);
+ cifs_server_unlock(server);
+ return rc;
+ }
+
+ midQ->mid_state = MID_REQUEST_SUBMITTED;
+ rc = smb_send(server, in_buf, len);
+ cifs_save_when_sent(midQ);
+
+ if (rc < 0)
+ server->sequence_number -= 2;
+
+ cifs_server_unlock(server);
+
+ if (rc < 0) {
+ delete_mid(midQ);
+ return rc;
+ }
+
+ /* Wait for a reply - allow signals to interrupt. */
+ rc = wait_event_interruptible(server->response_q,
+ (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
+ ((server->tcpStatus != CifsGood) &&
+ (server->tcpStatus != CifsNew)));
+
+ /* Were we interrupted by a signal ? */
+ spin_lock(&server->srv_lock);
+ if ((rc == -ERESTARTSYS) &&
+ (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
+ ((server->tcpStatus == CifsGood) ||
+ (server->tcpStatus == CifsNew))) {
+ spin_unlock(&server->srv_lock);
+
+ if (in_buf->Command == SMB_COM_TRANSACTION2) {
+ /* POSIX lock. We send a NT_CANCEL SMB to cause the
+ blocking lock to return. */
+ rc = send_cancel(server, &rqst, midQ);
+ if (rc) {
+ delete_mid(midQ);
+ return rc;
+ }
+ } else {
+ /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
+ to cause the blocking lock to return. */
+
+ rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
+
+ /* If we get -ENOLCK back the lock may have
+ already been removed. Don't exit in this case. */
+ if (rc && rc != -ENOLCK) {
+ delete_mid(midQ);
+ return rc;
+ }
+ }
+
+ rc = wait_for_response(server, midQ);
+ if (rc) {
+ send_cancel(server, &rqst, midQ);
+ spin_lock(&server->mid_lock);
+ if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
+ /* no longer considered to be "in-flight" */
+ midQ->callback = release_mid;
+ spin_unlock(&server->mid_lock);
+ return rc;
+ }
+ spin_unlock(&server->mid_lock);
+ }
+
+ /* We got the response - restart system call. */
+ rstart = 1;
+ spin_lock(&server->srv_lock);
+ }
+ spin_unlock(&server->srv_lock);
+
+ rc = cifs_sync_mid_result(midQ, server);
+ if (rc != 0)
+ return rc;
+
+ /* rcvd frame is ok */
+ if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
+ rc = -EIO;
+ cifs_tcon_dbg(VFS, "Bad MID state?\n");
+ goto out;
+ }
+
+ *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
+ memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
+ rc = cifs_check_receive(midQ, server, 0);
+out:
+ delete_mid(midQ);
+ if (rstart && rc == -EACCES)
+ return -ERESTARTSYS;
+ return rc;
+}
+
+/*
+ * Discard any remaining data in the current SMB. To do this, we borrow the
+ * current bigbuf.
+ */
+int
+cifs_discard_remaining_data(struct TCP_Server_Info *server)
+{
+ unsigned int rfclen = server->pdu_size;
+ size_t remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
+ server->total_read;
+
+ while (remaining > 0) {
+ ssize_t length;
+
+ length = cifs_discard_from_socket(server,
+ min_t(size_t, remaining,
+ CIFSMaxBufSize + MAX_HEADER_SIZE(server)));
+ if (length < 0)
+ return length;
+ server->total_read += length;
+ remaining -= length;
+ }
+
+ return 0;
+}
+
+static int
+__cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid,
+ bool malformed)
+{
+ int length;
+
+ length = cifs_discard_remaining_data(server);
+ dequeue_mid(mid, malformed);
+ mid->resp_buf = server->smallbuf;
+ server->smallbuf = NULL;
+ return length;
+}
+
+static int
+cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+{
+ struct cifs_readdata *rdata = mid->callback_data;
+
+ return __cifs_readv_discard(server, mid, rdata->result);
+}
+
+int
+cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
+{
+ int length, len;
+ unsigned int data_offset, data_len;
+ struct cifs_readdata *rdata = mid->callback_data;
+ char *buf = server->smallbuf;
+ unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server);
+ bool use_rdma_mr = false;
+
+ cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
+ __func__, mid->mid, rdata->offset, rdata->bytes);
+
+ /*
+ * read the rest of READ_RSP header (sans Data array), or whatever we
+ * can if there's not enough data. At this point, we've read down to
+ * the Mid.
+ */
+ len = min_t(unsigned int, buflen, server->vals->read_rsp_size) -
+ HEADER_SIZE(server) + 1;
+
+ length = cifs_read_from_socket(server,
+ buf + HEADER_SIZE(server) - 1, len);
+ if (length < 0)
+ return length;
+ server->total_read += length;
+
+ if (server->ops->is_session_expired &&
+ server->ops->is_session_expired(buf)) {
+ cifs_reconnect(server, true);
+ return -1;
+ }
+
+ if (server->ops->is_status_pending &&
+ server->ops->is_status_pending(buf, server)) {
+ cifs_discard_remaining_data(server);
+ return -1;
+ }
+
+ /* set up first two iov for signature check and to get credits */
+ rdata->iov[0].iov_base = buf;
+ rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server);
+ rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server);
+ rdata->iov[1].iov_len =
+ server->total_read - HEADER_PREAMBLE_SIZE(server);
+ cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
+ rdata->iov[0].iov_base, rdata->iov[0].iov_len);
+ cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
+ rdata->iov[1].iov_base, rdata->iov[1].iov_len);
+
+ /* Was the SMB read successful? */
+ rdata->result = server->ops->map_error(buf, false);
+ if (rdata->result != 0) {
+ cifs_dbg(FYI, "%s: server returned error %d\n",
+ __func__, rdata->result);
+ /* normal error on read response */
+ return __cifs_readv_discard(server, mid, false);
+ }
+
+ /* Is there enough to get to the rest of the READ_RSP header? */
+ if (server->total_read < server->vals->read_rsp_size) {
+ cifs_dbg(FYI, "%s: server returned short header. got=%u expected=%zu\n",
+ __func__, server->total_read,
+ server->vals->read_rsp_size);
+ rdata->result = -EIO;
+ return cifs_readv_discard(server, mid);
+ }
+
+ data_offset = server->ops->read_data_offset(buf) +
+ HEADER_PREAMBLE_SIZE(server);
+ if (data_offset < server->total_read) {
+ /*
+ * win2k8 sometimes sends an offset of 0 when the read
+ * is beyond the EOF. Treat it as if the data starts just after
+ * the header.
+ */
+ cifs_dbg(FYI, "%s: data offset (%u) inside read response header\n",
+ __func__, data_offset);
+ data_offset = server->total_read;
+ } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) {
+ /* data_offset is beyond the end of smallbuf */
+ cifs_dbg(FYI, "%s: data offset (%u) beyond end of smallbuf\n",
+ __func__, data_offset);
+ rdata->result = -EIO;
+ return cifs_readv_discard(server, mid);
+ }
+
+ cifs_dbg(FYI, "%s: total_read=%u data_offset=%u\n",
+ __func__, server->total_read, data_offset);
+
+ len = data_offset - server->total_read;
+ if (len > 0) {
+ /* read any junk before data into the rest of smallbuf */
+ length = cifs_read_from_socket(server,
+ buf + server->total_read, len);
+ if (length < 0)
+ return length;
+ server->total_read += length;
+ }
+
+ /* how much data is in the response? */
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ use_rdma_mr = rdata->mr;
+#endif
+ data_len = server->ops->read_data_length(buf, use_rdma_mr);
+ if (!use_rdma_mr && (data_offset + data_len > buflen)) {
+ /* data_len is corrupt -- discard frame */
+ rdata->result = -EIO;
+ return cifs_readv_discard(server, mid);
+ }
+
+#ifdef CONFIG_CIFS_SMB_DIRECT
+ if (rdata->mr)
+ length = data_len; /* An RDMA read is already done. */
+ else
+#endif
+ length = cifs_read_iter_from_socket(server, &rdata->iter,
+ data_len);
+ if (length > 0)
+ rdata->got_bytes += length;
+ server->total_read += length;
+
+ cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n",
+ server->total_read, buflen, data_len);
+
+ /* discard anything left over */
+ if (server->total_read < buflen)
+ return cifs_readv_discard(server, mid);
+
+ dequeue_mid(mid, false);
+ mid->resp_buf = server->smallbuf;
+ server->smallbuf = NULL;
+ return length;
+}