1 // SPDX-License-Identifier: LGPL-2.1
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 * Jeremy Allison (jra@samba.org) 2006.
11 #include <linux/list.h>
12 #include <linux/gfp.h>
13 #include <linux/wait.h>
14 #include <linux/net.h>
15 #include <linux/delay.h>
16 #include <linux/freezer.h>
17 #include <linux/tcp.h>
18 #include <linux/bvec.h>
19 #include <linux/highmem.h>
20 #include <linux/uaccess.h>
21 #include <asm/processor.h>
22 #include <linux/mempool.h>
23 #include <linux/sched/signal.h>
26 #include "cifsproto.h"
27 #include "cifs_debug.h"
28 #include "smb2proto.h"
29 #include "smbdirect.h"
31 /* Max number of iovectors we can use off the stack when sending requests. */
32 #define CIFS_MAX_IOV_SIZE 8
35 cifs_wake_up_task(struct mid_q_entry *mid)
37 wake_up_process(mid->callback_data);
41 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
43 struct mid_q_entry *temp;
46 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
50 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
51 memset(temp, 0, sizeof(struct mid_q_entry));
52 kref_init(&temp->refcount);
53 temp->mid = get_mid(smb_buffer);
54 temp->pid = current->pid;
55 temp->command = cpu_to_le16(smb_buffer->Command);
56 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
57 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
58 /* when mid allocated can be before when sent */
59 temp->when_alloc = jiffies;
60 temp->server = server;
63 * The default is for the mid to be synchronous, so the
64 * default callback just wakes up the current task.
66 get_task_struct(current);
67 temp->creator = current;
68 temp->callback = cifs_wake_up_task;
69 temp->callback_data = current;
71 atomic_inc(&midCount);
72 temp->mid_state = MID_REQUEST_ALLOCATED;
76 static void _cifs_mid_q_entry_release(struct kref *refcount)
78 struct mid_q_entry *midEntry =
79 container_of(refcount, struct mid_q_entry, refcount);
80 #ifdef CONFIG_CIFS_STATS2
81 __le16 command = midEntry->server->vals->lock_cmd;
82 __u16 smb_cmd = le16_to_cpu(midEntry->command);
84 unsigned long roundtrip_time;
86 struct TCP_Server_Info *server = midEntry->server;
88 if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
89 midEntry->mid_state == MID_RESPONSE_RECEIVED &&
90 server->ops->handle_cancelled_mid)
91 server->ops->handle_cancelled_mid(midEntry, server);
93 midEntry->mid_state = MID_FREE;
94 atomic_dec(&midCount);
95 if (midEntry->large_buf)
96 cifs_buf_release(midEntry->resp_buf);
98 cifs_small_buf_release(midEntry->resp_buf);
99 #ifdef CONFIG_CIFS_STATS2
101 if (now < midEntry->when_alloc)
102 cifs_server_dbg(VFS, "Invalid mid allocation time\n");
103 roundtrip_time = now - midEntry->when_alloc;
105 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
106 if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
107 server->slowest_cmd[smb_cmd] = roundtrip_time;
108 server->fastest_cmd[smb_cmd] = roundtrip_time;
110 if (server->slowest_cmd[smb_cmd] < roundtrip_time)
111 server->slowest_cmd[smb_cmd] = roundtrip_time;
112 else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
113 server->fastest_cmd[smb_cmd] = roundtrip_time;
115 cifs_stats_inc(&server->num_cmds[smb_cmd]);
116 server->time_per_cmd[smb_cmd] += roundtrip_time;
119 * commands taking longer than one second (default) can be indications
120 * that something is wrong, unless it is quite a slow link or a very
121 * busy server. Note that this calc is unlikely or impossible to wrap
122 * as long as slow_rsp_threshold is not set way above recommended max
123 * value (32767 ie 9 hours) and is generally harmless even if wrong
124 * since only affects debug counters - so leaving the calc as simple
125 * comparison rather than doing multiple conversions and overflow
128 if ((slow_rsp_threshold != 0) &&
129 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
130 (midEntry->command != command)) {
132 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
133 * NB: le16_to_cpu returns unsigned so can not be negative below
135 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
136 cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
138 trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
139 midEntry->when_sent, midEntry->when_received);
140 if (cifsFYI & CIFS_TIMER) {
141 pr_debug("slow rsp: cmd %d mid %llu",
142 midEntry->command, midEntry->mid);
143 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
144 now - midEntry->when_alloc,
145 now - midEntry->when_sent,
146 now - midEntry->when_received);
150 put_task_struct(midEntry->creator);
152 mempool_free(midEntry, cifs_mid_poolp);
155 void cifs_mid_q_entry_release(struct mid_q_entry *midEntry)
157 spin_lock(&GlobalMid_Lock);
158 kref_put(&midEntry->refcount, _cifs_mid_q_entry_release);
159 spin_unlock(&GlobalMid_Lock);
162 void DeleteMidQEntry(struct mid_q_entry *midEntry)
164 cifs_mid_q_entry_release(midEntry);
168 cifs_delete_mid(struct mid_q_entry *mid)
170 spin_lock(&GlobalMid_Lock);
171 if (!(mid->mid_flags & MID_DELETED)) {
172 list_del_init(&mid->qhead);
173 mid->mid_flags |= MID_DELETED;
175 spin_unlock(&GlobalMid_Lock);
177 DeleteMidQEntry(mid);
181 * smb_send_kvec - send an array of kvecs to the server
182 * @server: Server to send the data to
183 * @smb_msg: Message to send
184 * @sent: amount of data sent on socket is stored here
186 * Our basic "send data to server" function. Should be called with srv_mutex
187 * held. The caller is responsible for handling the results.
190 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
195 struct socket *ssocket = server->ssocket;
199 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
200 smb_msg->msg_namelen = sizeof(struct sockaddr);
201 smb_msg->msg_control = NULL;
202 smb_msg->msg_controllen = 0;
203 if (server->noblocksnd)
204 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
206 smb_msg->msg_flags = MSG_NOSIGNAL;
208 while (msg_data_left(smb_msg)) {
210 * If blocking send, we try 3 times, since each can block
211 * for 5 seconds. For nonblocking we have to try more
212 * but wait increasing amounts of time allowing time for
213 * socket to clear. The overall time we wait in either
214 * case to send on the socket is about 15 seconds.
215 * Similarly we wait for 15 seconds for a response from
216 * the server in SendReceive[2] for the server to send
217 * a response back for most types of requests (except
218 * SMB Write past end of file which can be slow, and
219 * blocking lock operations). NFS waits slightly longer
220 * than CIFS, but this can make it take longer for
221 * nonresponsive servers to be detected and 15 seconds
222 * is more than enough time for modern networks to
223 * send a packet. In most cases if we fail to send
224 * after the retries we will kill the socket and
225 * reconnect which may clear the network problem.
227 rc = sock_sendmsg(ssocket, smb_msg);
231 (!server->noblocksnd && (retries > 2))) {
232 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
236 msleep(1 << retries);
244 /* should never happen, letting socket clear before
245 retrying is our only obvious option here */
246 cifs_server_dbg(VFS, "tcp sent no data\n");
251 /* send was at least partially successful */
253 retries = 0; /* in case we get ENOSPC on the next send */
259 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
264 unsigned long buflen = 0;
266 if (server->vals->header_preamble_size == 0 &&
267 rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
268 iov = &rqst->rq_iov[1];
269 nvec = rqst->rq_nvec - 1;
272 nvec = rqst->rq_nvec;
275 /* total up iov array first */
276 for (i = 0; i < nvec; i++)
277 buflen += iov[i].iov_len;
280 * Add in the page array if there is one. The caller needs to make
281 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
282 * multiple pages ends at page boundary, rq_tailsz needs to be set to
285 if (rqst->rq_npages) {
286 if (rqst->rq_npages == 1)
287 buflen += rqst->rq_tailsz;
290 * If there is more than one page, calculate the
291 * buffer length based on rq_offset and rq_tailsz
293 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
295 buflen += rqst->rq_tailsz;
303 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
304 struct smb_rqst *rqst)
309 unsigned int send_length = 0;
311 sigset_t mask, oldmask;
312 size_t total_len = 0, sent, size;
313 struct socket *ssocket = server->ssocket;
314 struct msghdr smb_msg;
315 __be32 rfc1002_marker;
317 if (cifs_rdma_enabled(server)) {
318 /* return -EAGAIN when connecting or reconnecting */
320 if (server->smbd_conn)
321 rc = smbd_send(server, num_rqst, rqst);
328 if (fatal_signal_pending(current)) {
329 cifs_dbg(FYI, "signal pending before send request\n");
333 /* cork the socket */
334 tcp_sock_set_cork(ssocket->sk, true);
336 for (j = 0; j < num_rqst; j++)
337 send_length += smb_rqst_len(server, &rqst[j]);
338 rfc1002_marker = cpu_to_be32(send_length);
341 * We should not allow signals to interrupt the network send because
342 * any partial send will cause session reconnects thus increasing
343 * latency of system calls and overload a server with unnecessary
348 sigprocmask(SIG_BLOCK, &mask, &oldmask);
350 /* Generate a rfc1002 marker for SMB2+ */
351 if (server->vals->header_preamble_size == 0) {
353 .iov_base = &rfc1002_marker,
356 iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
357 rc = smb_send_kvec(server, &smb_msg, &sent);
365 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
367 for (j = 0; j < num_rqst; j++) {
368 iov = rqst[j].rq_iov;
369 n_vec = rqst[j].rq_nvec;
372 for (i = 0; i < n_vec; i++) {
373 dump_smb(iov[i].iov_base, iov[i].iov_len);
374 size += iov[i].iov_len;
377 iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
379 rc = smb_send_kvec(server, &smb_msg, &sent);
385 /* now walk the page array and send each page in it */
386 for (i = 0; i < rqst[j].rq_npages; i++) {
389 bvec.bv_page = rqst[j].rq_pages[i];
390 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
393 iov_iter_bvec(&smb_msg.msg_iter, WRITE,
394 &bvec, 1, bvec.bv_len);
395 rc = smb_send_kvec(server, &smb_msg, &sent);
404 sigprocmask(SIG_SETMASK, &oldmask, NULL);
407 * If signal is pending but we have already sent the whole packet to
408 * the server we need to return success status to allow a corresponding
409 * mid entry to be kept in the pending requests queue thus allowing
410 * to handle responses from the server by the client.
412 * If only part of the packet has been sent there is no need to hide
413 * interrupt because the session will be reconnected anyway, so there
414 * won't be any response from the server to handle.
417 if (signal_pending(current) && (total_len != send_length)) {
418 cifs_dbg(FYI, "signal is pending after attempt to send\n");
423 tcp_sock_set_cork(ssocket->sk, false);
425 if ((total_len > 0) && (total_len != send_length)) {
426 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
427 send_length, total_len);
429 * If we have only sent part of an SMB then the next SMB could
430 * be taken as the remainder of this one. We need to kill the
431 * socket so the server throws away the partial SMB
433 cifs_signal_cifsd_for_reconnect(server, false);
434 trace_smb3_partial_send_reconnect(server->CurrentMid,
435 server->conn_id, server->hostname);
438 if (rc < 0 && rc != -EINTR)
439 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
448 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
449 struct smb_rqst *rqst, int flags)
452 struct smb2_transform_hdr *tr_hdr;
453 struct smb_rqst cur_rqst[MAX_COMPOUND];
456 if (!(flags & CIFS_TRANSFORM_REQ))
457 return __smb_send_rqst(server, num_rqst, rqst);
459 if (num_rqst > MAX_COMPOUND - 1)
462 if (!server->ops->init_transform_rq) {
463 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
467 tr_hdr = kzalloc(sizeof(*tr_hdr), GFP_NOFS);
471 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
472 memset(&iov, 0, sizeof(iov));
474 iov.iov_base = tr_hdr;
475 iov.iov_len = sizeof(*tr_hdr);
476 cur_rqst[0].rq_iov = &iov;
477 cur_rqst[0].rq_nvec = 1;
479 rc = server->ops->init_transform_rq(server, num_rqst + 1,
484 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
485 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
492 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
493 unsigned int smb_buf_length)
496 struct smb_rqst rqst = { .rq_iov = iov,
499 iov[0].iov_base = smb_buffer;
501 iov[1].iov_base = (char *)smb_buffer + 4;
502 iov[1].iov_len = smb_buf_length;
504 return __smb_send_rqst(server, 1, &rqst);
508 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
509 const int timeout, const int flags,
510 unsigned int *instance)
516 int scredits, in_flight;
519 t = MAX_JIFFY_OFFSET;
521 t = msecs_to_jiffies(timeout);
523 optype = flags & CIFS_OP_MASK;
527 credits = server->ops->get_credits_field(server, optype);
528 /* Since an echo is already inflight, no need to wait to send another */
529 if (*credits <= 0 && optype == CIFS_ECHO_OP)
532 spin_lock(&server->req_lock);
533 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
534 /* oplock breaks must not be held up */
536 if (server->in_flight > server->max_in_flight)
537 server->max_in_flight = server->in_flight;
539 *instance = server->reconnect_instance;
541 in_flight = server->in_flight;
542 spin_unlock(&server->req_lock);
544 trace_smb3_nblk_credits(server->CurrentMid,
545 server->conn_id, server->hostname, scredits, -1, in_flight);
546 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
547 __func__, 1, scredits);
553 if (*credits < num_credits) {
555 spin_unlock(&server->req_lock);
557 cifs_num_waiters_inc(server);
558 rc = wait_event_killable_timeout(server->request_q,
559 has_credits(server, credits, num_credits), t);
560 cifs_num_waiters_dec(server);
562 spin_lock(&server->req_lock);
564 in_flight = server->in_flight;
565 spin_unlock(&server->req_lock);
567 trace_smb3_credit_timeout(server->CurrentMid,
568 server->conn_id, server->hostname, scredits,
569 num_credits, in_flight);
570 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
574 if (rc == -ERESTARTSYS)
576 spin_lock(&server->req_lock);
578 spin_unlock(&server->req_lock);
580 spin_lock(&cifs_tcp_ses_lock);
581 if (server->tcpStatus == CifsExiting) {
582 spin_unlock(&cifs_tcp_ses_lock);
585 spin_unlock(&cifs_tcp_ses_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 spin_lock(&server->req_lock);
601 if (!optype && num_credits == 1 &&
602 server->in_flight > 2 * MAX_COMPOUND &&
603 *credits <= MAX_COMPOUND) {
604 spin_unlock(&server->req_lock);
606 cifs_num_waiters_inc(server);
607 rc = wait_event_killable_timeout(
609 has_credits(server, credits,
612 cifs_num_waiters_dec(server);
614 spin_lock(&server->req_lock);
616 in_flight = server->in_flight;
617 spin_unlock(&server->req_lock);
619 trace_smb3_credit_timeout(
621 server->conn_id, server->hostname,
622 scredits, num_credits, in_flight);
623 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
627 if (rc == -ERESTARTSYS)
629 spin_lock(&server->req_lock);
634 * Can not count locking commands against total
635 * as they are allowed to block on server.
638 /* update # of requests on the wire to server */
639 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
640 *credits -= num_credits;
641 server->in_flight += num_credits;
642 if (server->in_flight > server->max_in_flight)
643 server->max_in_flight = server->in_flight;
644 *instance = server->reconnect_instance;
647 in_flight = server->in_flight;
648 spin_unlock(&server->req_lock);
650 trace_smb3_waitff_credits(server->CurrentMid,
651 server->conn_id, server->hostname, scredits,
652 -(num_credits), in_flight);
653 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
654 __func__, num_credits, scredits);
662 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
663 unsigned int *instance)
665 return wait_for_free_credits(server, 1, -1, flags,
670 wait_for_compound_request(struct TCP_Server_Info *server, int num,
671 const int flags, unsigned int *instance)
674 int scredits, in_flight;
676 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
678 spin_lock(&server->req_lock);
680 in_flight = server->in_flight;
682 if (*credits < num) {
684 * If the server is tight on resources or just gives us less
685 * credits for other reasons (e.g. requests are coming out of
686 * order and the server delays granting more credits until it
687 * processes a missing mid) and we exhausted most available
688 * credits there may be situations when we try to send
689 * a compound request but we don't have enough credits. At this
690 * point the client needs to decide if it should wait for
691 * additional credits or fail the request. If at least one
692 * request is in flight there is a high probability that the
693 * server will return enough credits to satisfy this compound
696 * Return immediately if no requests in flight since we will be
697 * stuck on waiting for credits.
699 if (server->in_flight == 0) {
700 spin_unlock(&server->req_lock);
701 trace_smb3_insufficient_credits(server->CurrentMid,
702 server->conn_id, server->hostname, scredits,
704 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
705 __func__, in_flight, num, scredits);
709 spin_unlock(&server->req_lock);
711 return wait_for_free_credits(server, num, 60000, flags,
716 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
717 unsigned int *num, struct cifs_credits *credits)
721 credits->instance = server->reconnect_instance;
725 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
726 struct mid_q_entry **ppmidQ)
728 spin_lock(&cifs_tcp_ses_lock);
729 if (ses->ses_status == SES_NEW) {
730 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
731 (in_buf->Command != SMB_COM_NEGOTIATE)) {
732 spin_unlock(&cifs_tcp_ses_lock);
735 /* else ok - we are setting up session */
738 if (ses->ses_status == SES_EXITING) {
739 /* check if SMB session is bad because we are setting it up */
740 if (in_buf->Command != SMB_COM_LOGOFF_ANDX) {
741 spin_unlock(&cifs_tcp_ses_lock);
744 /* else ok - we are shutting down session */
746 spin_unlock(&cifs_tcp_ses_lock);
748 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
751 spin_lock(&GlobalMid_Lock);
752 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
753 spin_unlock(&GlobalMid_Lock);
758 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
762 error = wait_event_freezekillable_unsafe(server->response_q,
763 midQ->mid_state != MID_REQUEST_SUBMITTED);
771 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
774 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
775 struct mid_q_entry *mid;
777 if (rqst->rq_iov[0].iov_len != 4 ||
778 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
779 return ERR_PTR(-EIO);
781 /* enable signing if server requires it */
783 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
785 mid = AllocMidQEntry(hdr, server);
787 return ERR_PTR(-ENOMEM);
789 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
791 DeleteMidQEntry(mid);
799 * Send a SMB request and set the callback function in the mid to handle
800 * the result. Caller is responsible for dealing with timeouts.
803 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
804 mid_receive_t *receive, mid_callback_t *callback,
805 mid_handle_t *handle, void *cbdata, const int flags,
806 const struct cifs_credits *exist_credits)
809 struct mid_q_entry *mid;
810 struct cifs_credits credits = { .value = 0, .instance = 0 };
811 unsigned int instance;
814 optype = flags & CIFS_OP_MASK;
816 if ((flags & CIFS_HAS_CREDITS) == 0) {
817 rc = wait_for_free_request(server, flags, &instance);
821 credits.instance = instance;
823 instance = exist_credits->instance;
825 cifs_server_lock(server);
828 * We can't use credits obtained from the previous session to send this
829 * request. Check if there were reconnects after we obtained credits and
830 * return -EAGAIN in such cases to let callers handle it.
832 if (instance != server->reconnect_instance) {
833 cifs_server_unlock(server);
834 add_credits_and_wake_if(server, &credits, optype);
838 mid = server->ops->setup_async_request(server, rqst);
840 cifs_server_unlock(server);
841 add_credits_and_wake_if(server, &credits, optype);
845 mid->receive = receive;
846 mid->callback = callback;
847 mid->callback_data = cbdata;
848 mid->handle = handle;
849 mid->mid_state = MID_REQUEST_SUBMITTED;
851 /* put it on the pending_mid_q */
852 spin_lock(&GlobalMid_Lock);
853 list_add_tail(&mid->qhead, &server->pending_mid_q);
854 spin_unlock(&GlobalMid_Lock);
857 * Need to store the time in mid before calling I/O. For call_async,
858 * I/O response may come back and free the mid entry on another thread.
860 cifs_save_when_sent(mid);
861 cifs_in_send_inc(server);
862 rc = smb_send_rqst(server, 1, rqst, flags);
863 cifs_in_send_dec(server);
866 revert_current_mid(server, mid->credits);
867 server->sequence_number -= 2;
868 cifs_delete_mid(mid);
871 cifs_server_unlock(server);
876 add_credits_and_wake_if(server, &credits, optype);
882 * Send an SMB Request. No response info (other than return code)
883 * needs to be parsed.
885 * flags indicate the type of request buffer and how long to wait
886 * and whether to log NT STATUS code (error) before mapping it to POSIX error
890 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
891 char *in_buf, int flags)
898 iov[0].iov_base = in_buf;
899 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
900 flags |= CIFS_NO_RSP_BUF;
901 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
902 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
908 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
912 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
913 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
915 spin_lock(&GlobalMid_Lock);
916 switch (mid->mid_state) {
917 case MID_RESPONSE_RECEIVED:
918 spin_unlock(&GlobalMid_Lock);
920 case MID_RETRY_NEEDED:
923 case MID_RESPONSE_MALFORMED:
930 if (!(mid->mid_flags & MID_DELETED)) {
931 list_del_init(&mid->qhead);
932 mid->mid_flags |= MID_DELETED;
934 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
935 __func__, mid->mid, mid->mid_state);
938 spin_unlock(&GlobalMid_Lock);
940 DeleteMidQEntry(mid);
945 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
946 struct mid_q_entry *mid)
948 return server->ops->send_cancel ?
949 server->ops->send_cancel(server, rqst, mid) : 0;
953 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
956 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
958 dump_smb(mid->resp_buf, min_t(u32, 92, len));
960 /* convert the length into a more usable form */
964 struct smb_rqst rqst = { .rq_iov = iov,
967 iov[0].iov_base = mid->resp_buf;
969 iov[1].iov_base = (char *)mid->resp_buf + 4;
970 iov[1].iov_len = len - 4;
971 /* FIXME: add code to kill session */
972 rc = cifs_verify_signature(&rqst, server,
973 mid->sequence_number);
975 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
979 /* BB special case reconnect tid and uid here? */
980 return map_and_check_smb_error(mid, log_error);
984 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
985 struct smb_rqst *rqst)
988 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
989 struct mid_q_entry *mid;
991 if (rqst->rq_iov[0].iov_len != 4 ||
992 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
993 return ERR_PTR(-EIO);
995 rc = allocate_mid(ses, hdr, &mid);
998 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
1000 cifs_delete_mid(mid);
1007 cifs_compound_callback(struct mid_q_entry *mid)
1009 struct TCP_Server_Info *server = mid->server;
1010 struct cifs_credits credits;
1012 credits.value = server->ops->get_credits(mid);
1013 credits.instance = server->reconnect_instance;
1015 add_credits(server, &credits, mid->optype);
1019 cifs_compound_last_callback(struct mid_q_entry *mid)
1021 cifs_compound_callback(mid);
1022 cifs_wake_up_task(mid);
1026 cifs_cancelled_callback(struct mid_q_entry *mid)
1028 cifs_compound_callback(mid);
1029 DeleteMidQEntry(mid);
1033 * Return a channel (master if none) of @ses that can be used to send
1036 * If we are currently binding a new channel (negprot/sess.setup),
1037 * return the new incomplete channel.
1039 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1047 index = (uint)atomic_inc_return(&ses->chan_seq);
1049 spin_lock(&ses->chan_lock);
1050 index %= ses->chan_count;
1051 spin_unlock(&ses->chan_lock);
1053 return ses->chans[index].server;
1057 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1058 struct TCP_Server_Info *server,
1059 const int flags, const int num_rqst, struct smb_rqst *rqst,
1060 int *resp_buf_type, struct kvec *resp_iov)
1062 int i, j, optype, rc = 0;
1063 struct mid_q_entry *midQ[MAX_COMPOUND];
1064 bool cancelled_mid[MAX_COMPOUND] = {false};
1065 struct cifs_credits credits[MAX_COMPOUND] = {
1066 { .value = 0, .instance = 0 }
1068 unsigned int instance;
1071 optype = flags & CIFS_OP_MASK;
1073 for (i = 0; i < num_rqst; i++)
1074 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1076 if (!ses || !ses->server || !server) {
1077 cifs_dbg(VFS, "Null session\n");
1081 spin_lock(&cifs_tcp_ses_lock);
1082 if (server->tcpStatus == CifsExiting) {
1083 spin_unlock(&cifs_tcp_ses_lock);
1086 spin_unlock(&cifs_tcp_ses_lock);
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 cifs_server_lock(server);
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 cifs_server_unlock(server);
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 cifs_server_unlock(server);
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 cifs_server_unlock(server);
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 spin_lock(&cifs_tcp_ses_lock);
1190 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1191 spin_unlock(&cifs_tcp_ses_lock);
1193 cifs_server_lock(server);
1194 smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec);
1195 cifs_server_unlock(server);
1197 spin_lock(&cifs_tcp_ses_lock);
1199 spin_unlock(&cifs_tcp_ses_lock);
1201 for (i = 0; i < num_rqst; i++) {
1202 rc = wait_for_response(server, midQ[i]);
1207 for (; i < num_rqst; i++) {
1208 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1209 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1210 send_cancel(server, &rqst[i], midQ[i]);
1211 spin_lock(&GlobalMid_Lock);
1212 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1213 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1214 midQ[i]->callback = cifs_cancelled_callback;
1215 cancelled_mid[i] = true;
1216 credits[i].value = 0;
1218 spin_unlock(&GlobalMid_Lock);
1222 for (i = 0; i < num_rqst; i++) {
1226 rc = cifs_sync_mid_result(midQ[i], server);
1228 /* mark this mid as cancelled to not free it below */
1229 cancelled_mid[i] = true;
1233 if (!midQ[i]->resp_buf ||
1234 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1236 cifs_dbg(FYI, "Bad MID state?\n");
1240 buf = (char *)midQ[i]->resp_buf;
1241 resp_iov[i].iov_base = buf;
1242 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1243 server->vals->header_preamble_size;
1245 if (midQ[i]->large_buf)
1246 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1248 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1250 rc = server->ops->check_receive(midQ[i], server,
1251 flags & CIFS_LOG_ERROR);
1253 /* mark it so buf will not be freed by cifs_delete_mid */
1254 if ((flags & CIFS_NO_RSP_BUF) == 0)
1255 midQ[i]->resp_buf = NULL;
1260 * Compounding is never used during session establish.
1262 spin_lock(&cifs_tcp_ses_lock);
1263 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1265 .iov_base = resp_iov[0].iov_base,
1266 .iov_len = resp_iov[0].iov_len
1268 spin_unlock(&cifs_tcp_ses_lock);
1269 cifs_server_lock(server);
1270 smb311_update_preauth_hash(ses, server, &iov, 1);
1271 cifs_server_unlock(server);
1272 spin_lock(&cifs_tcp_ses_lock);
1274 spin_unlock(&cifs_tcp_ses_lock);
1278 * This will dequeue all mids. After this it is important that the
1279 * demultiplex_thread will not process any of these mids any futher.
1280 * This is prevented above by using a noop callback that will not
1281 * wake this thread except for the very last PDU.
1283 for (i = 0; i < num_rqst; i++) {
1284 if (!cancelled_mid[i])
1285 cifs_delete_mid(midQ[i]);
1292 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1293 struct TCP_Server_Info *server,
1294 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1295 struct kvec *resp_iov)
1297 return compound_send_recv(xid, ses, server, flags, 1,
1298 rqst, resp_buf_type, resp_iov);
1302 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1303 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1304 const int flags, struct kvec *resp_iov)
1306 struct smb_rqst rqst;
1307 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1310 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1311 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1314 /* otherwise cifs_send_recv below sets resp_buf_type */
1315 *resp_buf_type = CIFS_NO_BUFFER;
1321 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1322 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1324 new_iov[0].iov_base = new_iov[1].iov_base;
1325 new_iov[0].iov_len = 4;
1326 new_iov[1].iov_base += 4;
1327 new_iov[1].iov_len -= 4;
1329 memset(&rqst, 0, sizeof(struct smb_rqst));
1330 rqst.rq_iov = new_iov;
1331 rqst.rq_nvec = n_vec + 1;
1333 rc = cifs_send_recv(xid, ses, ses->server,
1334 &rqst, resp_buf_type, flags, resp_iov);
1335 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1341 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1342 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1343 int *pbytes_returned, const int flags)
1346 struct mid_q_entry *midQ;
1347 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1348 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1349 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1350 struct cifs_credits credits = { .value = 1, .instance = 0 };
1351 struct TCP_Server_Info *server;
1354 cifs_dbg(VFS, "Null smb session\n");
1357 server = ses->server;
1358 if (server == NULL) {
1359 cifs_dbg(VFS, "Null tcp session\n");
1363 spin_lock(&cifs_tcp_ses_lock);
1364 if (server->tcpStatus == CifsExiting) {
1365 spin_unlock(&cifs_tcp_ses_lock);
1368 spin_unlock(&cifs_tcp_ses_lock);
1370 /* Ensure that we do not send more than 50 overlapping requests
1371 to the same server. We may make this configurable later or
1374 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1375 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1380 rc = wait_for_free_request(server, flags, &credits.instance);
1384 /* make sure that we sign in the same order that we send on this socket
1385 and avoid races inside tcp sendmsg code that could cause corruption
1388 cifs_server_lock(server);
1390 rc = allocate_mid(ses, in_buf, &midQ);
1392 cifs_server_unlock(server);
1393 /* Update # of requests on wire to server */
1394 add_credits(server, &credits, 0);
1398 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1400 cifs_server_unlock(server);
1404 midQ->mid_state = MID_REQUEST_SUBMITTED;
1406 cifs_in_send_inc(server);
1407 rc = smb_send(server, in_buf, len);
1408 cifs_in_send_dec(server);
1409 cifs_save_when_sent(midQ);
1412 server->sequence_number -= 2;
1414 cifs_server_unlock(server);
1419 rc = wait_for_response(server, midQ);
1421 send_cancel(server, &rqst, midQ);
1422 spin_lock(&GlobalMid_Lock);
1423 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1424 /* no longer considered to be "in-flight" */
1425 midQ->callback = DeleteMidQEntry;
1426 spin_unlock(&GlobalMid_Lock);
1427 add_credits(server, &credits, 0);
1430 spin_unlock(&GlobalMid_Lock);
1433 rc = cifs_sync_mid_result(midQ, server);
1435 add_credits(server, &credits, 0);
1439 if (!midQ->resp_buf || !out_buf ||
1440 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1442 cifs_server_dbg(VFS, "Bad MID state?\n");
1446 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1447 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1448 rc = cifs_check_receive(midQ, server, 0);
1450 cifs_delete_mid(midQ);
1451 add_credits(server, &credits, 0);
1456 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1457 blocking lock to return. */
1460 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1461 struct smb_hdr *in_buf,
1462 struct smb_hdr *out_buf)
1465 struct cifs_ses *ses = tcon->ses;
1466 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1468 /* We just modify the current in_buf to change
1469 the type of lock from LOCKING_ANDX_SHARED_LOCK
1470 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1471 LOCKING_ANDX_CANCEL_LOCK. */
1473 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1475 pSMB->hdr.Mid = get_next_mid(ses->server);
1477 return SendReceive(xid, ses, in_buf, out_buf,
1478 &bytes_returned, 0);
1482 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1483 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1484 int *pbytes_returned)
1488 struct mid_q_entry *midQ;
1489 struct cifs_ses *ses;
1490 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1491 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1492 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1493 unsigned int instance;
1494 struct TCP_Server_Info *server;
1496 if (tcon == NULL || tcon->ses == NULL) {
1497 cifs_dbg(VFS, "Null smb session\n");
1501 server = ses->server;
1503 if (server == NULL) {
1504 cifs_dbg(VFS, "Null tcp session\n");
1508 spin_lock(&cifs_tcp_ses_lock);
1509 if (server->tcpStatus == CifsExiting) {
1510 spin_unlock(&cifs_tcp_ses_lock);
1513 spin_unlock(&cifs_tcp_ses_lock);
1515 /* Ensure that we do not send more than 50 overlapping requests
1516 to the same server. We may make this configurable later or
1519 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1520 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1525 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1529 /* make sure that we sign in the same order that we send on this socket
1530 and avoid races inside tcp sendmsg code that could cause corruption
1533 cifs_server_lock(server);
1535 rc = allocate_mid(ses, in_buf, &midQ);
1537 cifs_server_unlock(server);
1541 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1543 cifs_delete_mid(midQ);
1544 cifs_server_unlock(server);
1548 midQ->mid_state = MID_REQUEST_SUBMITTED;
1549 cifs_in_send_inc(server);
1550 rc = smb_send(server, in_buf, len);
1551 cifs_in_send_dec(server);
1552 cifs_save_when_sent(midQ);
1555 server->sequence_number -= 2;
1557 cifs_server_unlock(server);
1560 cifs_delete_mid(midQ);
1564 /* Wait for a reply - allow signals to interrupt. */
1565 rc = wait_event_interruptible(server->response_q,
1566 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1567 ((server->tcpStatus != CifsGood) &&
1568 (server->tcpStatus != CifsNew)));
1570 /* Were we interrupted by a signal ? */
1571 spin_lock(&cifs_tcp_ses_lock);
1572 if ((rc == -ERESTARTSYS) &&
1573 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1574 ((server->tcpStatus == CifsGood) ||
1575 (server->tcpStatus == CifsNew))) {
1576 spin_unlock(&cifs_tcp_ses_lock);
1578 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1579 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1580 blocking lock to return. */
1581 rc = send_cancel(server, &rqst, midQ);
1583 cifs_delete_mid(midQ);
1587 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1588 to cause the blocking lock to return. */
1590 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1592 /* If we get -ENOLCK back the lock may have
1593 already been removed. Don't exit in this case. */
1594 if (rc && rc != -ENOLCK) {
1595 cifs_delete_mid(midQ);
1600 rc = wait_for_response(server, midQ);
1602 send_cancel(server, &rqst, midQ);
1603 spin_lock(&GlobalMid_Lock);
1604 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1605 /* no longer considered to be "in-flight" */
1606 midQ->callback = DeleteMidQEntry;
1607 spin_unlock(&GlobalMid_Lock);
1610 spin_unlock(&GlobalMid_Lock);
1613 /* We got the response - restart system call. */
1615 spin_lock(&cifs_tcp_ses_lock);
1617 spin_unlock(&cifs_tcp_ses_lock);
1619 rc = cifs_sync_mid_result(midQ, server);
1623 /* rcvd frame is ok */
1624 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1626 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1630 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1631 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1632 rc = cifs_check_receive(midQ, server, 0);
1634 cifs_delete_mid(midQ);
1635 if (rstart && rc == -EACCES)
1636 return -ERESTARTSYS;