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 spin_lock(&GlobalMid_Lock);
434 server->tcpStatus = CifsNeedReconnect;
435 spin_unlock(&GlobalMid_Lock);
436 trace_smb3_partial_send_reconnect(server->CurrentMid,
437 server->conn_id, server->hostname);
440 if (rc < 0 && rc != -EINTR)
441 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
450 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
451 struct smb_rqst *rqst, int flags)
454 struct smb2_transform_hdr *tr_hdr;
455 struct smb_rqst cur_rqst[MAX_COMPOUND];
458 if (!(flags & CIFS_TRANSFORM_REQ))
459 return __smb_send_rqst(server, num_rqst, rqst);
461 if (num_rqst > MAX_COMPOUND - 1)
464 if (!server->ops->init_transform_rq) {
465 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
469 tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS);
473 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
474 memset(&iov, 0, sizeof(iov));
475 memset(tr_hdr, 0, sizeof(*tr_hdr));
477 iov.iov_base = tr_hdr;
478 iov.iov_len = sizeof(*tr_hdr);
479 cur_rqst[0].rq_iov = &iov;
480 cur_rqst[0].rq_nvec = 1;
482 rc = server->ops->init_transform_rq(server, num_rqst + 1,
487 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
488 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
495 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
496 unsigned int smb_buf_length)
499 struct smb_rqst rqst = { .rq_iov = iov,
502 iov[0].iov_base = smb_buffer;
504 iov[1].iov_base = (char *)smb_buffer + 4;
505 iov[1].iov_len = smb_buf_length;
507 return __smb_send_rqst(server, 1, &rqst);
511 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
512 const int timeout, const int flags,
513 unsigned int *instance)
519 int scredits, in_flight;
522 t = MAX_JIFFY_OFFSET;
524 t = msecs_to_jiffies(timeout);
526 optype = flags & CIFS_OP_MASK;
530 credits = server->ops->get_credits_field(server, optype);
531 /* Since an echo is already inflight, no need to wait to send another */
532 if (*credits <= 0 && optype == CIFS_ECHO_OP)
535 spin_lock(&server->req_lock);
536 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
537 /* oplock breaks must not be held up */
539 if (server->in_flight > server->max_in_flight)
540 server->max_in_flight = server->in_flight;
542 *instance = server->reconnect_instance;
544 in_flight = server->in_flight;
545 spin_unlock(&server->req_lock);
547 trace_smb3_add_credits(server->CurrentMid,
548 server->conn_id, server->hostname, scredits, -1, in_flight);
549 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
550 __func__, 1, scredits);
556 if (*credits < num_credits) {
558 spin_unlock(&server->req_lock);
560 cifs_num_waiters_inc(server);
561 rc = wait_event_killable_timeout(server->request_q,
562 has_credits(server, credits, num_credits), t);
563 cifs_num_waiters_dec(server);
565 spin_lock(&server->req_lock);
567 in_flight = server->in_flight;
568 spin_unlock(&server->req_lock);
570 trace_smb3_credit_timeout(server->CurrentMid,
571 server->conn_id, server->hostname, scredits,
572 num_credits, in_flight);
573 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
577 if (rc == -ERESTARTSYS)
579 spin_lock(&server->req_lock);
581 if (server->tcpStatus == CifsExiting) {
582 spin_unlock(&server->req_lock);
587 * For normal commands, reserve the last MAX_COMPOUND
588 * credits to compound requests.
589 * Otherwise these compounds could be permanently
590 * starved for credits by single-credit requests.
592 * To prevent spinning CPU, block this thread until
593 * there are >MAX_COMPOUND credits available.
594 * But only do this is we already have a lot of
595 * credits in flight to avoid triggering this check
596 * for servers that are slow to hand out credits on
599 if (!optype && num_credits == 1 &&
600 server->in_flight > 2 * MAX_COMPOUND &&
601 *credits <= MAX_COMPOUND) {
602 spin_unlock(&server->req_lock);
604 cifs_num_waiters_inc(server);
605 rc = wait_event_killable_timeout(
607 has_credits(server, credits,
610 cifs_num_waiters_dec(server);
612 spin_lock(&server->req_lock);
614 in_flight = server->in_flight;
615 spin_unlock(&server->req_lock);
617 trace_smb3_credit_timeout(
619 server->conn_id, server->hostname,
620 scredits, num_credits, in_flight);
621 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
625 if (rc == -ERESTARTSYS)
627 spin_lock(&server->req_lock);
632 * Can not count locking commands against total
633 * as they are allowed to block on server.
636 /* update # of requests on the wire to server */
637 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
638 *credits -= num_credits;
639 server->in_flight += num_credits;
640 if (server->in_flight > server->max_in_flight)
641 server->max_in_flight = server->in_flight;
642 *instance = server->reconnect_instance;
645 in_flight = server->in_flight;
646 spin_unlock(&server->req_lock);
648 trace_smb3_add_credits(server->CurrentMid,
649 server->conn_id, server->hostname, scredits,
650 -(num_credits), in_flight);
651 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
652 __func__, num_credits, scredits);
660 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
661 unsigned int *instance)
663 return wait_for_free_credits(server, 1, -1, flags,
668 wait_for_compound_request(struct TCP_Server_Info *server, int num,
669 const int flags, unsigned int *instance)
672 int scredits, in_flight;
674 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
676 spin_lock(&server->req_lock);
678 in_flight = server->in_flight;
680 if (*credits < num) {
682 * If the server is tight on resources or just gives us less
683 * credits for other reasons (e.g. requests are coming out of
684 * order and the server delays granting more credits until it
685 * processes a missing mid) and we exhausted most available
686 * credits there may be situations when we try to send
687 * a compound request but we don't have enough credits. At this
688 * point the client needs to decide if it should wait for
689 * additional credits or fail the request. If at least one
690 * request is in flight there is a high probability that the
691 * server will return enough credits to satisfy this compound
694 * Return immediately if no requests in flight since we will be
695 * stuck on waiting for credits.
697 if (server->in_flight == 0) {
698 spin_unlock(&server->req_lock);
699 trace_smb3_insufficient_credits(server->CurrentMid,
700 server->conn_id, server->hostname, scredits,
702 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
703 __func__, in_flight, num, scredits);
707 spin_unlock(&server->req_lock);
709 return wait_for_free_credits(server, num, 60000, flags,
714 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
715 unsigned int *num, struct cifs_credits *credits)
719 credits->instance = server->reconnect_instance;
723 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
724 struct mid_q_entry **ppmidQ)
726 if (ses->server->tcpStatus == CifsExiting) {
730 if (ses->server->tcpStatus == CifsNeedReconnect) {
731 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
735 if (ses->status == CifsNew) {
736 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
737 (in_buf->Command != SMB_COM_NEGOTIATE))
739 /* else ok - we are setting up session */
742 if (ses->status == CifsExiting) {
743 /* check if SMB session is bad because we are setting it up */
744 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
746 /* else ok - we are shutting down session */
749 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
752 spin_lock(&GlobalMid_Lock);
753 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
754 spin_unlock(&GlobalMid_Lock);
759 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
763 error = wait_event_freezekillable_unsafe(server->response_q,
764 midQ->mid_state != MID_REQUEST_SUBMITTED);
772 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
775 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
776 struct mid_q_entry *mid;
778 if (rqst->rq_iov[0].iov_len != 4 ||
779 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
780 return ERR_PTR(-EIO);
782 /* enable signing if server requires it */
784 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
786 mid = AllocMidQEntry(hdr, server);
788 return ERR_PTR(-ENOMEM);
790 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
792 DeleteMidQEntry(mid);
800 * Send a SMB request and set the callback function in the mid to handle
801 * the result. Caller is responsible for dealing with timeouts.
804 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
805 mid_receive_t *receive, mid_callback_t *callback,
806 mid_handle_t *handle, void *cbdata, const int flags,
807 const struct cifs_credits *exist_credits)
810 struct mid_q_entry *mid;
811 struct cifs_credits credits = { .value = 0, .instance = 0 };
812 unsigned int instance;
815 optype = flags & CIFS_OP_MASK;
817 if ((flags & CIFS_HAS_CREDITS) == 0) {
818 rc = wait_for_free_request(server, flags, &instance);
822 credits.instance = instance;
824 instance = exist_credits->instance;
826 mutex_lock(&server->srv_mutex);
829 * We can't use credits obtained from the previous session to send this
830 * request. Check if there were reconnects after we obtained credits and
831 * return -EAGAIN in such cases to let callers handle it.
833 if (instance != server->reconnect_instance) {
834 mutex_unlock(&server->srv_mutex);
835 add_credits_and_wake_if(server, &credits, optype);
839 mid = server->ops->setup_async_request(server, rqst);
841 mutex_unlock(&server->srv_mutex);
842 add_credits_and_wake_if(server, &credits, optype);
846 mid->receive = receive;
847 mid->callback = callback;
848 mid->callback_data = cbdata;
849 mid->handle = handle;
850 mid->mid_state = MID_REQUEST_SUBMITTED;
852 /* put it on the pending_mid_q */
853 spin_lock(&GlobalMid_Lock);
854 list_add_tail(&mid->qhead, &server->pending_mid_q);
855 spin_unlock(&GlobalMid_Lock);
858 * Need to store the time in mid before calling I/O. For call_async,
859 * I/O response may come back and free the mid entry on another thread.
861 cifs_save_when_sent(mid);
862 cifs_in_send_inc(server);
863 rc = smb_send_rqst(server, 1, rqst, flags);
864 cifs_in_send_dec(server);
867 revert_current_mid(server, mid->credits);
868 server->sequence_number -= 2;
869 cifs_delete_mid(mid);
872 mutex_unlock(&server->srv_mutex);
877 add_credits_and_wake_if(server, &credits, optype);
883 * Send an SMB Request. No response info (other than return code)
884 * needs to be parsed.
886 * flags indicate the type of request buffer and how long to wait
887 * and whether to log NT STATUS code (error) before mapping it to POSIX error
891 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
892 char *in_buf, int flags)
899 iov[0].iov_base = in_buf;
900 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
901 flags |= CIFS_NO_RSP_BUF;
902 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
903 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
909 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
913 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
914 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
916 spin_lock(&GlobalMid_Lock);
917 switch (mid->mid_state) {
918 case MID_RESPONSE_RECEIVED:
919 spin_unlock(&GlobalMid_Lock);
921 case MID_RETRY_NEEDED:
924 case MID_RESPONSE_MALFORMED:
931 if (!(mid->mid_flags & MID_DELETED)) {
932 list_del_init(&mid->qhead);
933 mid->mid_flags |= MID_DELETED;
935 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
936 __func__, mid->mid, mid->mid_state);
939 spin_unlock(&GlobalMid_Lock);
941 DeleteMidQEntry(mid);
946 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
947 struct mid_q_entry *mid)
949 return server->ops->send_cancel ?
950 server->ops->send_cancel(server, rqst, mid) : 0;
954 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
957 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
959 dump_smb(mid->resp_buf, min_t(u32, 92, len));
961 /* convert the length into a more usable form */
965 struct smb_rqst rqst = { .rq_iov = iov,
968 iov[0].iov_base = mid->resp_buf;
970 iov[1].iov_base = (char *)mid->resp_buf + 4;
971 iov[1].iov_len = len - 4;
972 /* FIXME: add code to kill session */
973 rc = cifs_verify_signature(&rqst, server,
974 mid->sequence_number);
976 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
980 /* BB special case reconnect tid and uid here? */
981 return map_and_check_smb_error(mid, log_error);
985 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
986 struct smb_rqst *rqst)
989 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
990 struct mid_q_entry *mid;
992 if (rqst->rq_iov[0].iov_len != 4 ||
993 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
994 return ERR_PTR(-EIO);
996 rc = allocate_mid(ses, hdr, &mid);
999 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
1001 cifs_delete_mid(mid);
1008 cifs_compound_callback(struct mid_q_entry *mid)
1010 struct TCP_Server_Info *server = mid->server;
1011 struct cifs_credits credits;
1013 credits.value = server->ops->get_credits(mid);
1014 credits.instance = server->reconnect_instance;
1016 add_credits(server, &credits, mid->optype);
1020 cifs_compound_last_callback(struct mid_q_entry *mid)
1022 cifs_compound_callback(mid);
1023 cifs_wake_up_task(mid);
1027 cifs_cancelled_callback(struct mid_q_entry *mid)
1029 cifs_compound_callback(mid);
1030 DeleteMidQEntry(mid);
1034 * Return a channel (master if none) of @ses that can be used to send
1037 * If we are currently binding a new channel (negprot/sess.setup),
1038 * return the new incomplete channel.
1040 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1047 if (!ses->binding) {
1049 if (ses->chan_count > 1) {
1050 index = (uint)atomic_inc_return(&ses->chan_seq);
1051 index %= ses->chan_count;
1053 return ses->chans[index].server;
1055 return cifs_ses_server(ses);
1060 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1061 struct TCP_Server_Info *server,
1062 const int flags, const int num_rqst, struct smb_rqst *rqst,
1063 int *resp_buf_type, struct kvec *resp_iov)
1065 int i, j, optype, rc = 0;
1066 struct mid_q_entry *midQ[MAX_COMPOUND];
1067 bool cancelled_mid[MAX_COMPOUND] = {false};
1068 struct cifs_credits credits[MAX_COMPOUND] = {
1069 { .value = 0, .instance = 0 }
1071 unsigned int instance;
1074 optype = flags & CIFS_OP_MASK;
1076 for (i = 0; i < num_rqst; i++)
1077 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1079 if (!ses || !ses->server || !server) {
1080 cifs_dbg(VFS, "Null session\n");
1084 if (server->tcpStatus == CifsExiting)
1088 * Wait for all the requests to become available.
1089 * This approach still leaves the possibility to be stuck waiting for
1090 * credits if the server doesn't grant credits to the outstanding
1091 * requests and if the client is completely idle, not generating any
1093 * This can be handled by the eventual session reconnect.
1095 rc = wait_for_compound_request(server, num_rqst, flags,
1100 for (i = 0; i < num_rqst; i++) {
1101 credits[i].value = 1;
1102 credits[i].instance = instance;
1106 * Make sure that we sign in the same order that we send on this socket
1107 * and avoid races inside tcp sendmsg code that could cause corruption
1111 mutex_lock(&server->srv_mutex);
1114 * All the parts of the compound chain belong obtained credits from the
1115 * same session. We can not use credits obtained from the previous
1116 * session to send this request. Check if there were reconnects after
1117 * we obtained credits and return -EAGAIN in such cases to let callers
1120 if (instance != server->reconnect_instance) {
1121 mutex_unlock(&server->srv_mutex);
1122 for (j = 0; j < num_rqst; j++)
1123 add_credits(server, &credits[j], optype);
1127 for (i = 0; i < num_rqst; i++) {
1128 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1129 if (IS_ERR(midQ[i])) {
1130 revert_current_mid(server, i);
1131 for (j = 0; j < i; j++)
1132 cifs_delete_mid(midQ[j]);
1133 mutex_unlock(&server->srv_mutex);
1135 /* Update # of requests on wire to server */
1136 for (j = 0; j < num_rqst; j++)
1137 add_credits(server, &credits[j], optype);
1138 return PTR_ERR(midQ[i]);
1141 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1142 midQ[i]->optype = optype;
1144 * Invoke callback for every part of the compound chain
1145 * to calculate credits properly. Wake up this thread only when
1146 * the last element is received.
1148 if (i < num_rqst - 1)
1149 midQ[i]->callback = cifs_compound_callback;
1151 midQ[i]->callback = cifs_compound_last_callback;
1153 cifs_in_send_inc(server);
1154 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1155 cifs_in_send_dec(server);
1157 for (i = 0; i < num_rqst; i++)
1158 cifs_save_when_sent(midQ[i]);
1161 revert_current_mid(server, num_rqst);
1162 server->sequence_number -= 2;
1165 mutex_unlock(&server->srv_mutex);
1168 * If sending failed for some reason or it is an oplock break that we
1169 * will not receive a response to - return credits back
1171 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1172 for (i = 0; i < num_rqst; i++)
1173 add_credits(server, &credits[i], optype);
1178 * At this point the request is passed to the network stack - we assume
1179 * that any credits taken from the server structure on the client have
1180 * been spent and we can't return them back. Once we receive responses
1181 * we will collect credits granted by the server in the mid callbacks
1182 * and add those credits to the server structure.
1186 * Compounding is never used during session establish.
1188 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1189 mutex_lock(&server->srv_mutex);
1190 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1192 mutex_unlock(&server->srv_mutex);
1195 for (i = 0; i < num_rqst; i++) {
1196 rc = wait_for_response(server, midQ[i]);
1201 for (; i < num_rqst; i++) {
1202 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1203 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1204 send_cancel(server, &rqst[i], midQ[i]);
1205 spin_lock(&GlobalMid_Lock);
1206 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1207 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1208 midQ[i]->callback = cifs_cancelled_callback;
1209 cancelled_mid[i] = true;
1210 credits[i].value = 0;
1212 spin_unlock(&GlobalMid_Lock);
1216 for (i = 0; i < num_rqst; i++) {
1220 rc = cifs_sync_mid_result(midQ[i], server);
1222 /* mark this mid as cancelled to not free it below */
1223 cancelled_mid[i] = true;
1227 if (!midQ[i]->resp_buf ||
1228 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1230 cifs_dbg(FYI, "Bad MID state?\n");
1234 buf = (char *)midQ[i]->resp_buf;
1235 resp_iov[i].iov_base = buf;
1236 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1237 server->vals->header_preamble_size;
1239 if (midQ[i]->large_buf)
1240 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1242 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1244 rc = server->ops->check_receive(midQ[i], server,
1245 flags & CIFS_LOG_ERROR);
1247 /* mark it so buf will not be freed by cifs_delete_mid */
1248 if ((flags & CIFS_NO_RSP_BUF) == 0)
1249 midQ[i]->resp_buf = NULL;
1254 * Compounding is never used during session establish.
1256 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1258 .iov_base = resp_iov[0].iov_base,
1259 .iov_len = resp_iov[0].iov_len
1261 mutex_lock(&server->srv_mutex);
1262 smb311_update_preauth_hash(ses, &iov, 1);
1263 mutex_unlock(&server->srv_mutex);
1268 * This will dequeue all mids. After this it is important that the
1269 * demultiplex_thread will not process any of these mids any futher.
1270 * This is prevented above by using a noop callback that will not
1271 * wake this thread except for the very last PDU.
1273 for (i = 0; i < num_rqst; i++) {
1274 if (!cancelled_mid[i])
1275 cifs_delete_mid(midQ[i]);
1282 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1283 struct TCP_Server_Info *server,
1284 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1285 struct kvec *resp_iov)
1287 return compound_send_recv(xid, ses, server, flags, 1,
1288 rqst, resp_buf_type, resp_iov);
1292 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1293 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1294 const int flags, struct kvec *resp_iov)
1296 struct smb_rqst rqst;
1297 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1300 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1301 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1304 /* otherwise cifs_send_recv below sets resp_buf_type */
1305 *resp_buf_type = CIFS_NO_BUFFER;
1311 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1312 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1314 new_iov[0].iov_base = new_iov[1].iov_base;
1315 new_iov[0].iov_len = 4;
1316 new_iov[1].iov_base += 4;
1317 new_iov[1].iov_len -= 4;
1319 memset(&rqst, 0, sizeof(struct smb_rqst));
1320 rqst.rq_iov = new_iov;
1321 rqst.rq_nvec = n_vec + 1;
1323 rc = cifs_send_recv(xid, ses, ses->server,
1324 &rqst, resp_buf_type, flags, resp_iov);
1325 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1331 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1332 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1333 int *pbytes_returned, const int flags)
1336 struct mid_q_entry *midQ;
1337 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1338 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1339 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1340 struct cifs_credits credits = { .value = 1, .instance = 0 };
1341 struct TCP_Server_Info *server;
1344 cifs_dbg(VFS, "Null smb session\n");
1347 server = ses->server;
1348 if (server == NULL) {
1349 cifs_dbg(VFS, "Null tcp session\n");
1353 if (server->tcpStatus == CifsExiting)
1356 /* Ensure that we do not send more than 50 overlapping requests
1357 to the same server. We may make this configurable later or
1360 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1361 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1366 rc = wait_for_free_request(server, flags, &credits.instance);
1370 /* make sure that we sign in the same order that we send on this socket
1371 and avoid races inside tcp sendmsg code that could cause corruption
1374 mutex_lock(&server->srv_mutex);
1376 rc = allocate_mid(ses, in_buf, &midQ);
1378 mutex_unlock(&server->srv_mutex);
1379 /* Update # of requests on wire to server */
1380 add_credits(server, &credits, 0);
1384 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1386 mutex_unlock(&server->srv_mutex);
1390 midQ->mid_state = MID_REQUEST_SUBMITTED;
1392 cifs_in_send_inc(server);
1393 rc = smb_send(server, in_buf, len);
1394 cifs_in_send_dec(server);
1395 cifs_save_when_sent(midQ);
1398 server->sequence_number -= 2;
1400 mutex_unlock(&server->srv_mutex);
1405 rc = wait_for_response(server, midQ);
1407 send_cancel(server, &rqst, midQ);
1408 spin_lock(&GlobalMid_Lock);
1409 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1410 /* no longer considered to be "in-flight" */
1411 midQ->callback = DeleteMidQEntry;
1412 spin_unlock(&GlobalMid_Lock);
1413 add_credits(server, &credits, 0);
1416 spin_unlock(&GlobalMid_Lock);
1419 rc = cifs_sync_mid_result(midQ, server);
1421 add_credits(server, &credits, 0);
1425 if (!midQ->resp_buf || !out_buf ||
1426 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1428 cifs_server_dbg(VFS, "Bad MID state?\n");
1432 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1433 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1434 rc = cifs_check_receive(midQ, server, 0);
1436 cifs_delete_mid(midQ);
1437 add_credits(server, &credits, 0);
1442 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1443 blocking lock to return. */
1446 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1447 struct smb_hdr *in_buf,
1448 struct smb_hdr *out_buf)
1451 struct cifs_ses *ses = tcon->ses;
1452 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1454 /* We just modify the current in_buf to change
1455 the type of lock from LOCKING_ANDX_SHARED_LOCK
1456 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1457 LOCKING_ANDX_CANCEL_LOCK. */
1459 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1461 pSMB->hdr.Mid = get_next_mid(ses->server);
1463 return SendReceive(xid, ses, in_buf, out_buf,
1464 &bytes_returned, 0);
1468 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1469 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1470 int *pbytes_returned)
1474 struct mid_q_entry *midQ;
1475 struct cifs_ses *ses;
1476 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1477 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1478 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1479 unsigned int instance;
1480 struct TCP_Server_Info *server;
1482 if (tcon == NULL || tcon->ses == NULL) {
1483 cifs_dbg(VFS, "Null smb session\n");
1487 server = ses->server;
1489 if (server == NULL) {
1490 cifs_dbg(VFS, "Null tcp session\n");
1494 if (server->tcpStatus == CifsExiting)
1497 /* Ensure that we do not send more than 50 overlapping requests
1498 to the same server. We may make this configurable later or
1501 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1502 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1507 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1511 /* make sure that we sign in the same order that we send on this socket
1512 and avoid races inside tcp sendmsg code that could cause corruption
1515 mutex_lock(&server->srv_mutex);
1517 rc = allocate_mid(ses, in_buf, &midQ);
1519 mutex_unlock(&server->srv_mutex);
1523 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1525 cifs_delete_mid(midQ);
1526 mutex_unlock(&server->srv_mutex);
1530 midQ->mid_state = MID_REQUEST_SUBMITTED;
1531 cifs_in_send_inc(server);
1532 rc = smb_send(server, in_buf, len);
1533 cifs_in_send_dec(server);
1534 cifs_save_when_sent(midQ);
1537 server->sequence_number -= 2;
1539 mutex_unlock(&server->srv_mutex);
1542 cifs_delete_mid(midQ);
1546 /* Wait for a reply - allow signals to interrupt. */
1547 rc = wait_event_interruptible(server->response_q,
1548 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1549 ((server->tcpStatus != CifsGood) &&
1550 (server->tcpStatus != CifsNew)));
1552 /* Were we interrupted by a signal ? */
1553 if ((rc == -ERESTARTSYS) &&
1554 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1555 ((server->tcpStatus == CifsGood) ||
1556 (server->tcpStatus == CifsNew))) {
1558 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1559 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1560 blocking lock to return. */
1561 rc = send_cancel(server, &rqst, midQ);
1563 cifs_delete_mid(midQ);
1567 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1568 to cause the blocking lock to return. */
1570 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1572 /* If we get -ENOLCK back the lock may have
1573 already been removed. Don't exit in this case. */
1574 if (rc && rc != -ENOLCK) {
1575 cifs_delete_mid(midQ);
1580 rc = wait_for_response(server, midQ);
1582 send_cancel(server, &rqst, midQ);
1583 spin_lock(&GlobalMid_Lock);
1584 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1585 /* no longer considered to be "in-flight" */
1586 midQ->callback = DeleteMidQEntry;
1587 spin_unlock(&GlobalMid_Lock);
1590 spin_unlock(&GlobalMid_Lock);
1593 /* We got the response - restart system call. */
1597 rc = cifs_sync_mid_result(midQ, server);
1601 /* rcvd frame is ok */
1602 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1604 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1608 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1609 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1610 rc = cifs_check_receive(midQ, server, 0);
1612 cifs_delete_mid(midQ);
1613 if (rstart && rc == -EACCES)
1614 return -ERESTARTSYS;