1 // SPDX-License-Identifier: LGPL-2.1
5 * Copyright (C) International Business Machines Corp., 2002,2008
6 * Author(s): Steve French (sfrench@us.ibm.com)
7 * Jeremy Allison (jra@samba.org) 2006.
12 #include <linux/list.h>
13 #include <linux/gfp.h>
14 #include <linux/wait.h>
15 #include <linux/net.h>
16 #include <linux/delay.h>
17 #include <linux/freezer.h>
18 #include <linux/tcp.h>
19 #include <linux/bvec.h>
20 #include <linux/highmem.h>
21 #include <linux/uaccess.h>
22 #include <asm/processor.h>
23 #include <linux/mempool.h>
24 #include <linux/sched/signal.h>
27 #include "cifsproto.h"
28 #include "cifs_debug.h"
29 #include "smb2proto.h"
30 #include "smbdirect.h"
32 /* Max number of iovectors we can use off the stack when sending requests. */
33 #define CIFS_MAX_IOV_SIZE 8
36 cifs_wake_up_task(struct mid_q_entry *mid)
38 wake_up_process(mid->callback_data);
42 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
44 struct mid_q_entry *temp;
47 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
51 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
52 memset(temp, 0, sizeof(struct mid_q_entry));
53 kref_init(&temp->refcount);
54 temp->mid = get_mid(smb_buffer);
55 temp->pid = current->pid;
56 temp->command = cpu_to_le16(smb_buffer->Command);
57 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
58 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
59 /* when mid allocated can be before when sent */
60 temp->when_alloc = jiffies;
61 temp->server = server;
64 * The default is for the mid to be synchronous, so the
65 * default callback just wakes up the current task.
67 get_task_struct(current);
68 temp->creator = current;
69 temp->callback = cifs_wake_up_task;
70 temp->callback_data = current;
72 atomic_inc(&midCount);
73 temp->mid_state = MID_REQUEST_ALLOCATED;
77 static void _cifs_mid_q_entry_release(struct kref *refcount)
79 struct mid_q_entry *midEntry =
80 container_of(refcount, struct mid_q_entry, refcount);
81 #ifdef CONFIG_CIFS_STATS2
82 __le16 command = midEntry->server->vals->lock_cmd;
83 __u16 smb_cmd = le16_to_cpu(midEntry->command);
85 unsigned long roundtrip_time;
87 struct TCP_Server_Info *server = midEntry->server;
89 if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
90 midEntry->mid_state == MID_RESPONSE_RECEIVED &&
91 server->ops->handle_cancelled_mid)
92 server->ops->handle_cancelled_mid(midEntry, server);
94 midEntry->mid_state = MID_FREE;
95 atomic_dec(&midCount);
96 if (midEntry->large_buf)
97 cifs_buf_release(midEntry->resp_buf);
99 cifs_small_buf_release(midEntry->resp_buf);
100 #ifdef CONFIG_CIFS_STATS2
102 if (now < midEntry->when_alloc)
103 cifs_server_dbg(VFS, "Invalid mid allocation time\n");
104 roundtrip_time = now - midEntry->when_alloc;
106 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
107 if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
108 server->slowest_cmd[smb_cmd] = roundtrip_time;
109 server->fastest_cmd[smb_cmd] = roundtrip_time;
111 if (server->slowest_cmd[smb_cmd] < roundtrip_time)
112 server->slowest_cmd[smb_cmd] = roundtrip_time;
113 else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
114 server->fastest_cmd[smb_cmd] = roundtrip_time;
116 cifs_stats_inc(&server->num_cmds[smb_cmd]);
117 server->time_per_cmd[smb_cmd] += roundtrip_time;
120 * commands taking longer than one second (default) can be indications
121 * that something is wrong, unless it is quite a slow link or a very
122 * busy server. Note that this calc is unlikely or impossible to wrap
123 * as long as slow_rsp_threshold is not set way above recommended max
124 * value (32767 ie 9 hours) and is generally harmless even if wrong
125 * since only affects debug counters - so leaving the calc as simple
126 * comparison rather than doing multiple conversions and overflow
129 if ((slow_rsp_threshold != 0) &&
130 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
131 (midEntry->command != command)) {
133 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
134 * NB: le16_to_cpu returns unsigned so can not be negative below
136 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
137 cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
139 trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
140 midEntry->when_sent, midEntry->when_received);
141 if (cifsFYI & CIFS_TIMER) {
142 pr_debug("slow rsp: cmd %d mid %llu",
143 midEntry->command, midEntry->mid);
144 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
145 now - midEntry->when_alloc,
146 now - midEntry->when_sent,
147 now - midEntry->when_received);
151 put_task_struct(midEntry->creator);
153 mempool_free(midEntry, cifs_mid_poolp);
156 void cifs_mid_q_entry_release(struct mid_q_entry *midEntry)
158 spin_lock(&GlobalMid_Lock);
159 kref_put(&midEntry->refcount, _cifs_mid_q_entry_release);
160 spin_unlock(&GlobalMid_Lock);
163 void DeleteMidQEntry(struct mid_q_entry *midEntry)
165 cifs_mid_q_entry_release(midEntry);
169 cifs_delete_mid(struct mid_q_entry *mid)
171 spin_lock(&GlobalMid_Lock);
172 if (!(mid->mid_flags & MID_DELETED)) {
173 list_del_init(&mid->qhead);
174 mid->mid_flags |= MID_DELETED;
176 spin_unlock(&GlobalMid_Lock);
178 DeleteMidQEntry(mid);
182 * smb_send_kvec - send an array of kvecs to the server
183 * @server: Server to send the data to
184 * @smb_msg: Message to send
185 * @sent: amount of data sent on socket is stored here
187 * Our basic "send data to server" function. Should be called with srv_mutex
188 * held. The caller is responsible for handling the results.
191 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
196 struct socket *ssocket = server->ssocket;
200 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
201 smb_msg->msg_namelen = sizeof(struct sockaddr);
202 smb_msg->msg_control = NULL;
203 smb_msg->msg_controllen = 0;
204 if (server->noblocksnd)
205 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
207 smb_msg->msg_flags = MSG_NOSIGNAL;
209 while (msg_data_left(smb_msg)) {
211 * If blocking send, we try 3 times, since each can block
212 * for 5 seconds. For nonblocking we have to try more
213 * but wait increasing amounts of time allowing time for
214 * socket to clear. The overall time we wait in either
215 * case to send on the socket is about 15 seconds.
216 * Similarly we wait for 15 seconds for a response from
217 * the server in SendReceive[2] for the server to send
218 * a response back for most types of requests (except
219 * SMB Write past end of file which can be slow, and
220 * blocking lock operations). NFS waits slightly longer
221 * than CIFS, but this can make it take longer for
222 * nonresponsive servers to be detected and 15 seconds
223 * is more than enough time for modern networks to
224 * send a packet. In most cases if we fail to send
225 * after the retries we will kill the socket and
226 * reconnect which may clear the network problem.
228 rc = sock_sendmsg(ssocket, smb_msg);
232 (!server->noblocksnd && (retries > 2))) {
233 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
237 msleep(1 << retries);
245 /* should never happen, letting socket clear before
246 retrying is our only obvious option here */
247 cifs_server_dbg(VFS, "tcp sent no data\n");
252 /* send was at least partially successful */
254 retries = 0; /* in case we get ENOSPC on the next send */
260 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
265 unsigned long buflen = 0;
267 if (server->vals->header_preamble_size == 0 &&
268 rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
269 iov = &rqst->rq_iov[1];
270 nvec = rqst->rq_nvec - 1;
273 nvec = rqst->rq_nvec;
276 /* total up iov array first */
277 for (i = 0; i < nvec; i++)
278 buflen += iov[i].iov_len;
281 * Add in the page array if there is one. The caller needs to make
282 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
283 * multiple pages ends at page boundary, rq_tailsz needs to be set to
286 if (rqst->rq_npages) {
287 if (rqst->rq_npages == 1)
288 buflen += rqst->rq_tailsz;
291 * If there is more than one page, calculate the
292 * buffer length based on rq_offset and rq_tailsz
294 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
296 buflen += rqst->rq_tailsz;
304 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
305 struct smb_rqst *rqst)
310 unsigned int send_length = 0;
312 sigset_t mask, oldmask;
313 size_t total_len = 0, sent, size;
314 struct socket *ssocket = server->ssocket;
315 struct msghdr smb_msg;
316 __be32 rfc1002_marker;
318 if (cifs_rdma_enabled(server)) {
319 /* return -EAGAIN when connecting or reconnecting */
321 if (server->smbd_conn)
322 rc = smbd_send(server, num_rqst, rqst);
329 if (fatal_signal_pending(current)) {
330 cifs_dbg(FYI, "signal pending before send request\n");
334 /* cork the socket */
335 tcp_sock_set_cork(ssocket->sk, true);
337 for (j = 0; j < num_rqst; j++)
338 send_length += smb_rqst_len(server, &rqst[j]);
339 rfc1002_marker = cpu_to_be32(send_length);
342 * We should not allow signals to interrupt the network send because
343 * any partial send will cause session reconnects thus increasing
344 * latency of system calls and overload a server with unnecessary
349 sigprocmask(SIG_BLOCK, &mask, &oldmask);
351 /* Generate a rfc1002 marker for SMB2+ */
352 if (server->vals->header_preamble_size == 0) {
354 .iov_base = &rfc1002_marker,
357 iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
358 rc = smb_send_kvec(server, &smb_msg, &sent);
366 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
368 for (j = 0; j < num_rqst; j++) {
369 iov = rqst[j].rq_iov;
370 n_vec = rqst[j].rq_nvec;
373 for (i = 0; i < n_vec; i++) {
374 dump_smb(iov[i].iov_base, iov[i].iov_len);
375 size += iov[i].iov_len;
378 iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
380 rc = smb_send_kvec(server, &smb_msg, &sent);
386 /* now walk the page array and send each page in it */
387 for (i = 0; i < rqst[j].rq_npages; i++) {
390 bvec.bv_page = rqst[j].rq_pages[i];
391 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
394 iov_iter_bvec(&smb_msg.msg_iter, WRITE,
395 &bvec, 1, bvec.bv_len);
396 rc = smb_send_kvec(server, &smb_msg, &sent);
405 sigprocmask(SIG_SETMASK, &oldmask, NULL);
408 * If signal is pending but we have already sent the whole packet to
409 * the server we need to return success status to allow a corresponding
410 * mid entry to be kept in the pending requests queue thus allowing
411 * to handle responses from the server by the client.
413 * If only part of the packet has been sent there is no need to hide
414 * interrupt because the session will be reconnected anyway, so there
415 * won't be any response from the server to handle.
418 if (signal_pending(current) && (total_len != send_length)) {
419 cifs_dbg(FYI, "signal is pending after attempt to send\n");
424 tcp_sock_set_cork(ssocket->sk, false);
426 if ((total_len > 0) && (total_len != send_length)) {
427 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
428 send_length, total_len);
430 * If we have only sent part of an SMB then the next SMB could
431 * be taken as the remainder of this one. We need to kill the
432 * socket so the server throws away the partial SMB
434 spin_lock(&GlobalMid_Lock);
435 server->tcpStatus = CifsNeedReconnect;
436 spin_unlock(&GlobalMid_Lock);
437 trace_smb3_partial_send_reconnect(server->CurrentMid,
438 server->conn_id, server->hostname);
441 if (rc < 0 && rc != -EINTR)
442 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
451 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
452 struct smb_rqst *rqst, int flags)
455 struct smb2_transform_hdr *tr_hdr;
456 struct smb_rqst cur_rqst[MAX_COMPOUND];
459 if (!(flags & CIFS_TRANSFORM_REQ))
460 return __smb_send_rqst(server, num_rqst, rqst);
462 if (num_rqst > MAX_COMPOUND - 1)
465 if (!server->ops->init_transform_rq) {
466 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
470 tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS);
474 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
475 memset(&iov, 0, sizeof(iov));
476 memset(tr_hdr, 0, sizeof(*tr_hdr));
478 iov.iov_base = tr_hdr;
479 iov.iov_len = sizeof(*tr_hdr);
480 cur_rqst[0].rq_iov = &iov;
481 cur_rqst[0].rq_nvec = 1;
483 rc = server->ops->init_transform_rq(server, num_rqst + 1,
488 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
489 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
496 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
497 unsigned int smb_buf_length)
500 struct smb_rqst rqst = { .rq_iov = iov,
503 iov[0].iov_base = smb_buffer;
505 iov[1].iov_base = (char *)smb_buffer + 4;
506 iov[1].iov_len = smb_buf_length;
508 return __smb_send_rqst(server, 1, &rqst);
512 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
513 const int timeout, const int flags,
514 unsigned int *instance)
520 int scredits, in_flight;
523 t = MAX_JIFFY_OFFSET;
525 t = msecs_to_jiffies(timeout);
527 optype = flags & CIFS_OP_MASK;
531 credits = server->ops->get_credits_field(server, optype);
532 /* Since an echo is already inflight, no need to wait to send another */
533 if (*credits <= 0 && optype == CIFS_ECHO_OP)
536 spin_lock(&server->req_lock);
537 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
538 /* oplock breaks must not be held up */
540 if (server->in_flight > server->max_in_flight)
541 server->max_in_flight = server->in_flight;
543 *instance = server->reconnect_instance;
545 in_flight = server->in_flight;
546 spin_unlock(&server->req_lock);
548 trace_smb3_add_credits(server->CurrentMid,
549 server->conn_id, server->hostname, scredits, -1, in_flight);
550 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
551 __func__, 1, scredits);
557 if (*credits < num_credits) {
559 spin_unlock(&server->req_lock);
561 cifs_num_waiters_inc(server);
562 rc = wait_event_killable_timeout(server->request_q,
563 has_credits(server, credits, num_credits), t);
564 cifs_num_waiters_dec(server);
566 spin_lock(&server->req_lock);
568 in_flight = server->in_flight;
569 spin_unlock(&server->req_lock);
571 trace_smb3_credit_timeout(server->CurrentMid,
572 server->conn_id, server->hostname, scredits,
573 num_credits, in_flight);
574 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
578 if (rc == -ERESTARTSYS)
580 spin_lock(&server->req_lock);
582 if (server->tcpStatus == CifsExiting) {
583 spin_unlock(&server->req_lock);
588 * For normal commands, reserve the last MAX_COMPOUND
589 * credits to compound requests.
590 * Otherwise these compounds could be permanently
591 * starved for credits by single-credit requests.
593 * To prevent spinning CPU, block this thread until
594 * there are >MAX_COMPOUND credits available.
595 * But only do this is we already have a lot of
596 * credits in flight to avoid triggering this check
597 * for servers that are slow to hand out credits on
600 if (!optype && num_credits == 1 &&
601 server->in_flight > 2 * MAX_COMPOUND &&
602 *credits <= MAX_COMPOUND) {
603 spin_unlock(&server->req_lock);
605 cifs_num_waiters_inc(server);
606 rc = wait_event_killable_timeout(
608 has_credits(server, credits,
611 cifs_num_waiters_dec(server);
613 spin_lock(&server->req_lock);
615 in_flight = server->in_flight;
616 spin_unlock(&server->req_lock);
618 trace_smb3_credit_timeout(
620 server->conn_id, server->hostname,
621 scredits, num_credits, in_flight);
622 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
626 if (rc == -ERESTARTSYS)
628 spin_lock(&server->req_lock);
633 * Can not count locking commands against total
634 * as they are allowed to block on server.
637 /* update # of requests on the wire to server */
638 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
639 *credits -= num_credits;
640 server->in_flight += num_credits;
641 if (server->in_flight > server->max_in_flight)
642 server->max_in_flight = server->in_flight;
643 *instance = server->reconnect_instance;
646 in_flight = server->in_flight;
647 spin_unlock(&server->req_lock);
649 trace_smb3_add_credits(server->CurrentMid,
650 server->conn_id, server->hostname, scredits,
651 -(num_credits), in_flight);
652 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
653 __func__, num_credits, scredits);
661 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
662 unsigned int *instance)
664 return wait_for_free_credits(server, 1, -1, flags,
669 wait_for_compound_request(struct TCP_Server_Info *server, int num,
670 const int flags, unsigned int *instance)
673 int scredits, in_flight;
675 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
677 spin_lock(&server->req_lock);
679 in_flight = server->in_flight;
681 if (*credits < num) {
683 * If the server is tight on resources or just gives us less
684 * credits for other reasons (e.g. requests are coming out of
685 * order and the server delays granting more credits until it
686 * processes a missing mid) and we exhausted most available
687 * credits there may be situations when we try to send
688 * a compound request but we don't have enough credits. At this
689 * point the client needs to decide if it should wait for
690 * additional credits or fail the request. If at least one
691 * request is in flight there is a high probability that the
692 * server will return enough credits to satisfy this compound
695 * Return immediately if no requests in flight since we will be
696 * stuck on waiting for credits.
698 if (server->in_flight == 0) {
699 spin_unlock(&server->req_lock);
700 trace_smb3_insufficient_credits(server->CurrentMid,
701 server->conn_id, server->hostname, scredits,
703 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
704 __func__, in_flight, num, scredits);
708 spin_unlock(&server->req_lock);
710 return wait_for_free_credits(server, num, 60000, flags,
715 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
716 unsigned int *num, struct cifs_credits *credits)
720 credits->instance = server->reconnect_instance;
724 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
725 struct mid_q_entry **ppmidQ)
727 if (ses->server->tcpStatus == CifsExiting) {
731 if (ses->server->tcpStatus == CifsNeedReconnect) {
732 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
736 if (ses->status == CifsNew) {
737 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
738 (in_buf->Command != SMB_COM_NEGOTIATE))
740 /* else ok - we are setting up session */
743 if (ses->status == CifsExiting) {
744 /* check if SMB session is bad because we are setting it up */
745 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
747 /* else ok - we are shutting down session */
750 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
753 spin_lock(&GlobalMid_Lock);
754 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
755 spin_unlock(&GlobalMid_Lock);
760 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
764 error = wait_event_freezekillable_unsafe(server->response_q,
765 midQ->mid_state != MID_REQUEST_SUBMITTED);
773 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
776 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
777 struct mid_q_entry *mid;
779 if (rqst->rq_iov[0].iov_len != 4 ||
780 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
781 return ERR_PTR(-EIO);
783 /* enable signing if server requires it */
785 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
787 mid = AllocMidQEntry(hdr, server);
789 return ERR_PTR(-ENOMEM);
791 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
793 DeleteMidQEntry(mid);
801 * Send a SMB request and set the callback function in the mid to handle
802 * the result. Caller is responsible for dealing with timeouts.
805 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
806 mid_receive_t *receive, mid_callback_t *callback,
807 mid_handle_t *handle, void *cbdata, const int flags,
808 const struct cifs_credits *exist_credits)
811 struct mid_q_entry *mid;
812 struct cifs_credits credits = { .value = 0, .instance = 0 };
813 unsigned int instance;
816 optype = flags & CIFS_OP_MASK;
818 if ((flags & CIFS_HAS_CREDITS) == 0) {
819 rc = wait_for_free_request(server, flags, &instance);
823 credits.instance = instance;
825 instance = exist_credits->instance;
827 mutex_lock(&server->srv_mutex);
830 * We can't use credits obtained from the previous session to send this
831 * request. Check if there were reconnects after we obtained credits and
832 * return -EAGAIN in such cases to let callers handle it.
834 if (instance != server->reconnect_instance) {
835 mutex_unlock(&server->srv_mutex);
836 add_credits_and_wake_if(server, &credits, optype);
840 mid = server->ops->setup_async_request(server, rqst);
842 mutex_unlock(&server->srv_mutex);
843 add_credits_and_wake_if(server, &credits, optype);
847 mid->receive = receive;
848 mid->callback = callback;
849 mid->callback_data = cbdata;
850 mid->handle = handle;
851 mid->mid_state = MID_REQUEST_SUBMITTED;
853 /* put it on the pending_mid_q */
854 spin_lock(&GlobalMid_Lock);
855 list_add_tail(&mid->qhead, &server->pending_mid_q);
856 spin_unlock(&GlobalMid_Lock);
859 * Need to store the time in mid before calling I/O. For call_async,
860 * I/O response may come back and free the mid entry on another thread.
862 cifs_save_when_sent(mid);
863 cifs_in_send_inc(server);
864 rc = smb_send_rqst(server, 1, rqst, flags);
865 cifs_in_send_dec(server);
868 revert_current_mid(server, mid->credits);
869 server->sequence_number -= 2;
870 cifs_delete_mid(mid);
873 mutex_unlock(&server->srv_mutex);
878 add_credits_and_wake_if(server, &credits, optype);
884 * Send an SMB Request. No response info (other than return code)
885 * needs to be parsed.
887 * flags indicate the type of request buffer and how long to wait
888 * and whether to log NT STATUS code (error) before mapping it to POSIX error
892 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
893 char *in_buf, int flags)
900 iov[0].iov_base = in_buf;
901 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
902 flags |= CIFS_NO_RSP_BUF;
903 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
904 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
910 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
914 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
915 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
917 spin_lock(&GlobalMid_Lock);
918 switch (mid->mid_state) {
919 case MID_RESPONSE_RECEIVED:
920 spin_unlock(&GlobalMid_Lock);
922 case MID_RETRY_NEEDED:
925 case MID_RESPONSE_MALFORMED:
932 if (!(mid->mid_flags & MID_DELETED)) {
933 list_del_init(&mid->qhead);
934 mid->mid_flags |= MID_DELETED;
936 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
937 __func__, mid->mid, mid->mid_state);
940 spin_unlock(&GlobalMid_Lock);
942 DeleteMidQEntry(mid);
947 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
948 struct mid_q_entry *mid)
950 return server->ops->send_cancel ?
951 server->ops->send_cancel(server, rqst, mid) : 0;
955 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
958 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
960 dump_smb(mid->resp_buf, min_t(u32, 92, len));
962 /* convert the length into a more usable form */
966 struct smb_rqst rqst = { .rq_iov = iov,
969 iov[0].iov_base = mid->resp_buf;
971 iov[1].iov_base = (char *)mid->resp_buf + 4;
972 iov[1].iov_len = len - 4;
973 /* FIXME: add code to kill session */
974 rc = cifs_verify_signature(&rqst, server,
975 mid->sequence_number);
977 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
981 /* BB special case reconnect tid and uid here? */
982 return map_and_check_smb_error(mid, log_error);
986 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
987 struct smb_rqst *rqst)
990 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
991 struct mid_q_entry *mid;
993 if (rqst->rq_iov[0].iov_len != 4 ||
994 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
995 return ERR_PTR(-EIO);
997 rc = allocate_mid(ses, hdr, &mid);
1000 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
1002 cifs_delete_mid(mid);
1009 cifs_compound_callback(struct mid_q_entry *mid)
1011 struct TCP_Server_Info *server = mid->server;
1012 struct cifs_credits credits;
1014 credits.value = server->ops->get_credits(mid);
1015 credits.instance = server->reconnect_instance;
1017 add_credits(server, &credits, mid->optype);
1021 cifs_compound_last_callback(struct mid_q_entry *mid)
1023 cifs_compound_callback(mid);
1024 cifs_wake_up_task(mid);
1028 cifs_cancelled_callback(struct mid_q_entry *mid)
1030 cifs_compound_callback(mid);
1031 DeleteMidQEntry(mid);
1035 * Return a channel (master if none) of @ses that can be used to send
1038 * If we are currently binding a new channel (negprot/sess.setup),
1039 * return the new incomplete channel.
1041 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1048 if (!ses->binding) {
1050 if (ses->chan_count > 1) {
1051 index = (uint)atomic_inc_return(&ses->chan_seq);
1052 index %= ses->chan_count;
1054 return ses->chans[index].server;
1056 return cifs_ses_server(ses);
1061 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1062 struct TCP_Server_Info *server,
1063 const int flags, const int num_rqst, struct smb_rqst *rqst,
1064 int *resp_buf_type, struct kvec *resp_iov)
1066 int i, j, optype, rc = 0;
1067 struct mid_q_entry *midQ[MAX_COMPOUND];
1068 bool cancelled_mid[MAX_COMPOUND] = {false};
1069 struct cifs_credits credits[MAX_COMPOUND] = {
1070 { .value = 0, .instance = 0 }
1072 unsigned int instance;
1075 optype = flags & CIFS_OP_MASK;
1077 for (i = 0; i < num_rqst; i++)
1078 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1080 if (!ses || !ses->server || !server) {
1081 cifs_dbg(VFS, "Null session\n");
1085 if (server->tcpStatus == CifsExiting)
1089 * Wait for all the requests to become available.
1090 * This approach still leaves the possibility to be stuck waiting for
1091 * credits if the server doesn't grant credits to the outstanding
1092 * requests and if the client is completely idle, not generating any
1094 * This can be handled by the eventual session reconnect.
1096 rc = wait_for_compound_request(server, num_rqst, flags,
1101 for (i = 0; i < num_rqst; i++) {
1102 credits[i].value = 1;
1103 credits[i].instance = instance;
1107 * Make sure that we sign in the same order that we send on this socket
1108 * and avoid races inside tcp sendmsg code that could cause corruption
1112 mutex_lock(&server->srv_mutex);
1115 * All the parts of the compound chain belong obtained credits from the
1116 * same session. We can not use credits obtained from the previous
1117 * session to send this request. Check if there were reconnects after
1118 * we obtained credits and return -EAGAIN in such cases to let callers
1121 if (instance != server->reconnect_instance) {
1122 mutex_unlock(&server->srv_mutex);
1123 for (j = 0; j < num_rqst; j++)
1124 add_credits(server, &credits[j], optype);
1128 for (i = 0; i < num_rqst; i++) {
1129 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1130 if (IS_ERR(midQ[i])) {
1131 revert_current_mid(server, i);
1132 for (j = 0; j < i; j++)
1133 cifs_delete_mid(midQ[j]);
1134 mutex_unlock(&server->srv_mutex);
1136 /* Update # of requests on wire to server */
1137 for (j = 0; j < num_rqst; j++)
1138 add_credits(server, &credits[j], optype);
1139 return PTR_ERR(midQ[i]);
1142 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1143 midQ[i]->optype = optype;
1145 * Invoke callback for every part of the compound chain
1146 * to calculate credits properly. Wake up this thread only when
1147 * the last element is received.
1149 if (i < num_rqst - 1)
1150 midQ[i]->callback = cifs_compound_callback;
1152 midQ[i]->callback = cifs_compound_last_callback;
1154 cifs_in_send_inc(server);
1155 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1156 cifs_in_send_dec(server);
1158 for (i = 0; i < num_rqst; i++)
1159 cifs_save_when_sent(midQ[i]);
1162 revert_current_mid(server, num_rqst);
1163 server->sequence_number -= 2;
1166 mutex_unlock(&server->srv_mutex);
1169 * If sending failed for some reason or it is an oplock break that we
1170 * will not receive a response to - return credits back
1172 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1173 for (i = 0; i < num_rqst; i++)
1174 add_credits(server, &credits[i], optype);
1179 * At this point the request is passed to the network stack - we assume
1180 * that any credits taken from the server structure on the client have
1181 * been spent and we can't return them back. Once we receive responses
1182 * we will collect credits granted by the server in the mid callbacks
1183 * and add those credits to the server structure.
1187 * Compounding is never used during session establish.
1189 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1190 mutex_lock(&server->srv_mutex);
1191 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1193 mutex_unlock(&server->srv_mutex);
1196 for (i = 0; i < num_rqst; i++) {
1197 rc = wait_for_response(server, midQ[i]);
1202 for (; i < num_rqst; i++) {
1203 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1204 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1205 send_cancel(server, &rqst[i], midQ[i]);
1206 spin_lock(&GlobalMid_Lock);
1207 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1208 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1209 midQ[i]->callback = cifs_cancelled_callback;
1210 cancelled_mid[i] = true;
1211 credits[i].value = 0;
1213 spin_unlock(&GlobalMid_Lock);
1217 for (i = 0; i < num_rqst; i++) {
1221 rc = cifs_sync_mid_result(midQ[i], server);
1223 /* mark this mid as cancelled to not free it below */
1224 cancelled_mid[i] = true;
1228 if (!midQ[i]->resp_buf ||
1229 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1231 cifs_dbg(FYI, "Bad MID state?\n");
1235 buf = (char *)midQ[i]->resp_buf;
1236 resp_iov[i].iov_base = buf;
1237 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1238 server->vals->header_preamble_size;
1240 if (midQ[i]->large_buf)
1241 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1243 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1245 rc = server->ops->check_receive(midQ[i], server,
1246 flags & CIFS_LOG_ERROR);
1248 /* mark it so buf will not be freed by cifs_delete_mid */
1249 if ((flags & CIFS_NO_RSP_BUF) == 0)
1250 midQ[i]->resp_buf = NULL;
1255 * Compounding is never used during session establish.
1257 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1259 .iov_base = resp_iov[0].iov_base,
1260 .iov_len = resp_iov[0].iov_len
1262 mutex_lock(&server->srv_mutex);
1263 smb311_update_preauth_hash(ses, &iov, 1);
1264 mutex_unlock(&server->srv_mutex);
1269 * This will dequeue all mids. After this it is important that the
1270 * demultiplex_thread will not process any of these mids any futher.
1271 * This is prevented above by using a noop callback that will not
1272 * wake this thread except for the very last PDU.
1274 for (i = 0; i < num_rqst; i++) {
1275 if (!cancelled_mid[i])
1276 cifs_delete_mid(midQ[i]);
1283 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1284 struct TCP_Server_Info *server,
1285 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1286 struct kvec *resp_iov)
1288 return compound_send_recv(xid, ses, server, flags, 1,
1289 rqst, resp_buf_type, resp_iov);
1293 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1294 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1295 const int flags, struct kvec *resp_iov)
1297 struct smb_rqst rqst;
1298 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1301 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1302 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1305 /* otherwise cifs_send_recv below sets resp_buf_type */
1306 *resp_buf_type = CIFS_NO_BUFFER;
1312 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1313 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1315 new_iov[0].iov_base = new_iov[1].iov_base;
1316 new_iov[0].iov_len = 4;
1317 new_iov[1].iov_base += 4;
1318 new_iov[1].iov_len -= 4;
1320 memset(&rqst, 0, sizeof(struct smb_rqst));
1321 rqst.rq_iov = new_iov;
1322 rqst.rq_nvec = n_vec + 1;
1324 rc = cifs_send_recv(xid, ses, ses->server,
1325 &rqst, resp_buf_type, flags, resp_iov);
1326 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1332 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1333 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1334 int *pbytes_returned, const int flags)
1337 struct mid_q_entry *midQ;
1338 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1339 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1340 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1341 struct cifs_credits credits = { .value = 1, .instance = 0 };
1342 struct TCP_Server_Info *server;
1345 cifs_dbg(VFS, "Null smb session\n");
1348 server = ses->server;
1349 if (server == NULL) {
1350 cifs_dbg(VFS, "Null tcp session\n");
1354 if (server->tcpStatus == CifsExiting)
1357 /* Ensure that we do not send more than 50 overlapping requests
1358 to the same server. We may make this configurable later or
1361 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1362 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1367 rc = wait_for_free_request(server, flags, &credits.instance);
1371 /* make sure that we sign in the same order that we send on this socket
1372 and avoid races inside tcp sendmsg code that could cause corruption
1375 mutex_lock(&server->srv_mutex);
1377 rc = allocate_mid(ses, in_buf, &midQ);
1379 mutex_unlock(&server->srv_mutex);
1380 /* Update # of requests on wire to server */
1381 add_credits(server, &credits, 0);
1385 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1387 mutex_unlock(&server->srv_mutex);
1391 midQ->mid_state = MID_REQUEST_SUBMITTED;
1393 cifs_in_send_inc(server);
1394 rc = smb_send(server, in_buf, len);
1395 cifs_in_send_dec(server);
1396 cifs_save_when_sent(midQ);
1399 server->sequence_number -= 2;
1401 mutex_unlock(&server->srv_mutex);
1406 rc = wait_for_response(server, midQ);
1408 send_cancel(server, &rqst, midQ);
1409 spin_lock(&GlobalMid_Lock);
1410 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1411 /* no longer considered to be "in-flight" */
1412 midQ->callback = DeleteMidQEntry;
1413 spin_unlock(&GlobalMid_Lock);
1414 add_credits(server, &credits, 0);
1417 spin_unlock(&GlobalMid_Lock);
1420 rc = cifs_sync_mid_result(midQ, server);
1422 add_credits(server, &credits, 0);
1426 if (!midQ->resp_buf || !out_buf ||
1427 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1429 cifs_server_dbg(VFS, "Bad MID state?\n");
1433 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1434 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1435 rc = cifs_check_receive(midQ, server, 0);
1437 cifs_delete_mid(midQ);
1438 add_credits(server, &credits, 0);
1443 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1444 blocking lock to return. */
1447 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1448 struct smb_hdr *in_buf,
1449 struct smb_hdr *out_buf)
1452 struct cifs_ses *ses = tcon->ses;
1453 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1455 /* We just modify the current in_buf to change
1456 the type of lock from LOCKING_ANDX_SHARED_LOCK
1457 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1458 LOCKING_ANDX_CANCEL_LOCK. */
1460 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1462 pSMB->hdr.Mid = get_next_mid(ses->server);
1464 return SendReceive(xid, ses, in_buf, out_buf,
1465 &bytes_returned, 0);
1469 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1470 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1471 int *pbytes_returned)
1475 struct mid_q_entry *midQ;
1476 struct cifs_ses *ses;
1477 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1478 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1479 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1480 unsigned int instance;
1481 struct TCP_Server_Info *server;
1483 if (tcon == NULL || tcon->ses == NULL) {
1484 cifs_dbg(VFS, "Null smb session\n");
1488 server = ses->server;
1490 if (server == NULL) {
1491 cifs_dbg(VFS, "Null tcp session\n");
1495 if (server->tcpStatus == CifsExiting)
1498 /* Ensure that we do not send more than 50 overlapping requests
1499 to the same server. We may make this configurable later or
1502 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1503 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1508 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1512 /* make sure that we sign in the same order that we send on this socket
1513 and avoid races inside tcp sendmsg code that could cause corruption
1516 mutex_lock(&server->srv_mutex);
1518 rc = allocate_mid(ses, in_buf, &midQ);
1520 mutex_unlock(&server->srv_mutex);
1524 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1526 cifs_delete_mid(midQ);
1527 mutex_unlock(&server->srv_mutex);
1531 midQ->mid_state = MID_REQUEST_SUBMITTED;
1532 cifs_in_send_inc(server);
1533 rc = smb_send(server, in_buf, len);
1534 cifs_in_send_dec(server);
1535 cifs_save_when_sent(midQ);
1538 server->sequence_number -= 2;
1540 mutex_unlock(&server->srv_mutex);
1543 cifs_delete_mid(midQ);
1547 /* Wait for a reply - allow signals to interrupt. */
1548 rc = wait_event_interruptible(server->response_q,
1549 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1550 ((server->tcpStatus != CifsGood) &&
1551 (server->tcpStatus != CifsNew)));
1553 /* Were we interrupted by a signal ? */
1554 if ((rc == -ERESTARTSYS) &&
1555 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1556 ((server->tcpStatus == CifsGood) ||
1557 (server->tcpStatus == CifsNew))) {
1559 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1560 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1561 blocking lock to return. */
1562 rc = send_cancel(server, &rqst, midQ);
1564 cifs_delete_mid(midQ);
1568 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1569 to cause the blocking lock to return. */
1571 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1573 /* If we get -ENOLCK back the lock may have
1574 already been removed. Don't exit in this case. */
1575 if (rc && rc != -ENOLCK) {
1576 cifs_delete_mid(midQ);
1581 rc = wait_for_response(server, midQ);
1583 send_cancel(server, &rqst, midQ);
1584 spin_lock(&GlobalMid_Lock);
1585 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1586 /* no longer considered to be "in-flight" */
1587 midQ->callback = DeleteMidQEntry;
1588 spin_unlock(&GlobalMid_Lock);
1591 spin_unlock(&GlobalMid_Lock);
1594 /* We got the response - restart system call. */
1598 rc = cifs_sync_mid_result(midQ, server);
1602 /* rcvd frame is ok */
1603 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1605 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1609 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1610 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1611 rc = cifs_check_receive(midQ, server, 0);
1613 cifs_delete_mid(midQ);
1614 if (rstart && rc == -EACCES)
1615 return -ERESTARTSYS;