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.
8 * This library is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU Lesser General Public License as published
10 * by the Free Software Foundation; either version 2.1 of the License, or
11 * (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
16 * the GNU Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this library; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/list.h>
25 #include <linux/gfp.h>
26 #include <linux/wait.h>
27 #include <linux/net.h>
28 #include <linux/delay.h>
29 #include <linux/freezer.h>
30 #include <linux/tcp.h>
31 #include <linux/bvec.h>
32 #include <linux/highmem.h>
33 #include <linux/uaccess.h>
34 #include <asm/processor.h>
35 #include <linux/mempool.h>
36 #include <linux/sched/signal.h>
39 #include "cifsproto.h"
40 #include "cifs_debug.h"
41 #include "smb2proto.h"
42 #include "smbdirect.h"
44 /* Max number of iovectors we can use off the stack when sending requests. */
45 #define CIFS_MAX_IOV_SIZE 8
48 cifs_wake_up_task(struct mid_q_entry *mid)
50 wake_up_process(mid->callback_data);
54 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
56 struct mid_q_entry *temp;
59 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
63 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
64 memset(temp, 0, sizeof(struct mid_q_entry));
65 kref_init(&temp->refcount);
66 temp->mid = get_mid(smb_buffer);
67 temp->pid = current->pid;
68 temp->command = cpu_to_le16(smb_buffer->Command);
69 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
70 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
71 /* when mid allocated can be before when sent */
72 temp->when_alloc = jiffies;
73 temp->server = server;
76 * The default is for the mid to be synchronous, so the
77 * default callback just wakes up the current task.
79 get_task_struct(current);
80 temp->creator = current;
81 temp->callback = cifs_wake_up_task;
82 temp->callback_data = current;
84 atomic_inc(&midCount);
85 temp->mid_state = MID_REQUEST_ALLOCATED;
89 static void _cifs_mid_q_entry_release(struct kref *refcount)
91 struct mid_q_entry *midEntry =
92 container_of(refcount, struct mid_q_entry, refcount);
93 #ifdef CONFIG_CIFS_STATS2
94 __le16 command = midEntry->server->vals->lock_cmd;
95 __u16 smb_cmd = le16_to_cpu(midEntry->command);
97 unsigned long roundtrip_time;
99 struct TCP_Server_Info *server = midEntry->server;
101 if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
102 midEntry->mid_state == MID_RESPONSE_RECEIVED &&
103 server->ops->handle_cancelled_mid)
104 server->ops->handle_cancelled_mid(midEntry->resp_buf, server);
106 midEntry->mid_state = MID_FREE;
107 atomic_dec(&midCount);
108 if (midEntry->large_buf)
109 cifs_buf_release(midEntry->resp_buf);
111 cifs_small_buf_release(midEntry->resp_buf);
112 #ifdef CONFIG_CIFS_STATS2
114 if (now < midEntry->when_alloc)
115 cifs_server_dbg(VFS, "Invalid mid allocation time\n");
116 roundtrip_time = now - midEntry->when_alloc;
118 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
119 if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
120 server->slowest_cmd[smb_cmd] = roundtrip_time;
121 server->fastest_cmd[smb_cmd] = roundtrip_time;
123 if (server->slowest_cmd[smb_cmd] < roundtrip_time)
124 server->slowest_cmd[smb_cmd] = roundtrip_time;
125 else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
126 server->fastest_cmd[smb_cmd] = roundtrip_time;
128 cifs_stats_inc(&server->num_cmds[smb_cmd]);
129 server->time_per_cmd[smb_cmd] += roundtrip_time;
132 * commands taking longer than one second (default) can be indications
133 * that something is wrong, unless it is quite a slow link or a very
134 * busy server. Note that this calc is unlikely or impossible to wrap
135 * as long as slow_rsp_threshold is not set way above recommended max
136 * value (32767 ie 9 hours) and is generally harmless even if wrong
137 * since only affects debug counters - so leaving the calc as simple
138 * comparison rather than doing multiple conversions and overflow
141 if ((slow_rsp_threshold != 0) &&
142 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
143 (midEntry->command != command)) {
145 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
146 * NB: le16_to_cpu returns unsigned so can not be negative below
148 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
149 cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
151 trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
152 midEntry->when_sent, midEntry->when_received);
153 if (cifsFYI & CIFS_TIMER) {
154 pr_debug("slow rsp: cmd %d mid %llu",
155 midEntry->command, midEntry->mid);
156 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
157 now - midEntry->when_alloc,
158 now - midEntry->when_sent,
159 now - midEntry->when_received);
163 put_task_struct(midEntry->creator);
165 mempool_free(midEntry, cifs_mid_poolp);
168 void cifs_mid_q_entry_release(struct mid_q_entry *midEntry)
170 spin_lock(&GlobalMid_Lock);
171 kref_put(&midEntry->refcount, _cifs_mid_q_entry_release);
172 spin_unlock(&GlobalMid_Lock);
175 void DeleteMidQEntry(struct mid_q_entry *midEntry)
177 cifs_mid_q_entry_release(midEntry);
181 cifs_delete_mid(struct mid_q_entry *mid)
183 spin_lock(&GlobalMid_Lock);
184 if (!(mid->mid_flags & MID_DELETED)) {
185 list_del_init(&mid->qhead);
186 mid->mid_flags |= MID_DELETED;
188 spin_unlock(&GlobalMid_Lock);
190 DeleteMidQEntry(mid);
194 * smb_send_kvec - send an array of kvecs to the server
195 * @server: Server to send the data to
196 * @smb_msg: Message to send
197 * @sent: amount of data sent on socket is stored here
199 * Our basic "send data to server" function. Should be called with srv_mutex
200 * held. The caller is responsible for handling the results.
203 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
208 struct socket *ssocket = server->ssocket;
212 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
213 smb_msg->msg_namelen = sizeof(struct sockaddr);
214 smb_msg->msg_control = NULL;
215 smb_msg->msg_controllen = 0;
216 if (server->noblocksnd)
217 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
219 smb_msg->msg_flags = MSG_NOSIGNAL;
221 while (msg_data_left(smb_msg)) {
223 * If blocking send, we try 3 times, since each can block
224 * for 5 seconds. For nonblocking we have to try more
225 * but wait increasing amounts of time allowing time for
226 * socket to clear. The overall time we wait in either
227 * case to send on the socket is about 15 seconds.
228 * Similarly we wait for 15 seconds for a response from
229 * the server in SendReceive[2] for the server to send
230 * a response back for most types of requests (except
231 * SMB Write past end of file which can be slow, and
232 * blocking lock operations). NFS waits slightly longer
233 * than CIFS, but this can make it take longer for
234 * nonresponsive servers to be detected and 15 seconds
235 * is more than enough time for modern networks to
236 * send a packet. In most cases if we fail to send
237 * after the retries we will kill the socket and
238 * reconnect which may clear the network problem.
240 rc = sock_sendmsg(ssocket, smb_msg);
244 (!server->noblocksnd && (retries > 2))) {
245 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
249 msleep(1 << retries);
257 /* should never happen, letting socket clear before
258 retrying is our only obvious option here */
259 cifs_server_dbg(VFS, "tcp sent no data\n");
264 /* send was at least partially successful */
266 retries = 0; /* in case we get ENOSPC on the next send */
272 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
277 unsigned long buflen = 0;
279 if (server->vals->header_preamble_size == 0 &&
280 rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
281 iov = &rqst->rq_iov[1];
282 nvec = rqst->rq_nvec - 1;
285 nvec = rqst->rq_nvec;
288 /* total up iov array first */
289 for (i = 0; i < nvec; i++)
290 buflen += iov[i].iov_len;
293 * Add in the page array if there is one. The caller needs to make
294 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
295 * multiple pages ends at page boundary, rq_tailsz needs to be set to
298 if (rqst->rq_npages) {
299 if (rqst->rq_npages == 1)
300 buflen += rqst->rq_tailsz;
303 * If there is more than one page, calculate the
304 * buffer length based on rq_offset and rq_tailsz
306 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
308 buflen += rqst->rq_tailsz;
316 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
317 struct smb_rqst *rqst)
322 unsigned int send_length = 0;
324 sigset_t mask, oldmask;
325 size_t total_len = 0, sent, size;
326 struct socket *ssocket = server->ssocket;
327 struct msghdr smb_msg;
328 __be32 rfc1002_marker;
330 if (cifs_rdma_enabled(server)) {
331 /* return -EAGAIN when connecting or reconnecting */
333 if (server->smbd_conn)
334 rc = smbd_send(server, num_rqst, rqst);
341 if (fatal_signal_pending(current)) {
342 cifs_dbg(FYI, "signal pending before send request\n");
346 /* cork the socket */
347 tcp_sock_set_cork(ssocket->sk, true);
349 for (j = 0; j < num_rqst; j++)
350 send_length += smb_rqst_len(server, &rqst[j]);
351 rfc1002_marker = cpu_to_be32(send_length);
354 * We should not allow signals to interrupt the network send because
355 * any partial send will cause session reconnects thus increasing
356 * latency of system calls and overload a server with unnecessary
361 sigprocmask(SIG_BLOCK, &mask, &oldmask);
363 /* Generate a rfc1002 marker for SMB2+ */
364 if (server->vals->header_preamble_size == 0) {
366 .iov_base = &rfc1002_marker,
369 iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
370 rc = smb_send_kvec(server, &smb_msg, &sent);
378 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
380 for (j = 0; j < num_rqst; j++) {
381 iov = rqst[j].rq_iov;
382 n_vec = rqst[j].rq_nvec;
385 for (i = 0; i < n_vec; i++) {
386 dump_smb(iov[i].iov_base, iov[i].iov_len);
387 size += iov[i].iov_len;
390 iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
392 rc = smb_send_kvec(server, &smb_msg, &sent);
398 /* now walk the page array and send each page in it */
399 for (i = 0; i < rqst[j].rq_npages; i++) {
402 bvec.bv_page = rqst[j].rq_pages[i];
403 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
406 iov_iter_bvec(&smb_msg.msg_iter, WRITE,
407 &bvec, 1, bvec.bv_len);
408 rc = smb_send_kvec(server, &smb_msg, &sent);
417 sigprocmask(SIG_SETMASK, &oldmask, NULL);
420 * If signal is pending but we have already sent the whole packet to
421 * the server we need to return success status to allow a corresponding
422 * mid entry to be kept in the pending requests queue thus allowing
423 * to handle responses from the server by the client.
425 * If only part of the packet has been sent there is no need to hide
426 * interrupt because the session will be reconnected anyway, so there
427 * won't be any response from the server to handle.
430 if (signal_pending(current) && (total_len != send_length)) {
431 cifs_dbg(FYI, "signal is pending after attempt to send\n");
436 tcp_sock_set_cork(ssocket->sk, false);
438 if ((total_len > 0) && (total_len != send_length)) {
439 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
440 send_length, total_len);
442 * If we have only sent part of an SMB then the next SMB could
443 * be taken as the remainder of this one. We need to kill the
444 * socket so the server throws away the partial SMB
446 server->tcpStatus = CifsNeedReconnect;
447 trace_smb3_partial_send_reconnect(server->CurrentMid,
451 if (rc < 0 && rc != -EINTR)
452 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
461 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
462 struct smb_rqst *rqst, int flags)
465 struct smb2_transform_hdr *tr_hdr;
466 struct smb_rqst cur_rqst[MAX_COMPOUND];
469 if (!(flags & CIFS_TRANSFORM_REQ))
470 return __smb_send_rqst(server, num_rqst, rqst);
472 if (num_rqst > MAX_COMPOUND - 1)
475 if (!server->ops->init_transform_rq) {
476 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
480 tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS);
484 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
485 memset(&iov, 0, sizeof(iov));
486 memset(tr_hdr, 0, sizeof(*tr_hdr));
488 iov.iov_base = tr_hdr;
489 iov.iov_len = sizeof(*tr_hdr);
490 cur_rqst[0].rq_iov = &iov;
491 cur_rqst[0].rq_nvec = 1;
493 rc = server->ops->init_transform_rq(server, num_rqst + 1,
498 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
499 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
506 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
507 unsigned int smb_buf_length)
510 struct smb_rqst rqst = { .rq_iov = iov,
513 iov[0].iov_base = smb_buffer;
515 iov[1].iov_base = (char *)smb_buffer + 4;
516 iov[1].iov_len = smb_buf_length;
518 return __smb_send_rqst(server, 1, &rqst);
522 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
523 const int timeout, const int flags,
524 unsigned int *instance)
530 int scredits = server->credits;
533 t = MAX_JIFFY_OFFSET;
535 t = msecs_to_jiffies(timeout);
537 optype = flags & CIFS_OP_MASK;
541 credits = server->ops->get_credits_field(server, optype);
542 /* Since an echo is already inflight, no need to wait to send another */
543 if (*credits <= 0 && optype == CIFS_ECHO_OP)
546 spin_lock(&server->req_lock);
547 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
548 /* oplock breaks must not be held up */
550 if (server->in_flight > server->max_in_flight)
551 server->max_in_flight = server->in_flight;
553 *instance = server->reconnect_instance;
554 spin_unlock(&server->req_lock);
559 if (*credits < num_credits) {
560 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 trace_smb3_credit_timeout(server->CurrentMid,
567 server->hostname, num_credits, 0);
568 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
572 if (rc == -ERESTARTSYS)
574 spin_lock(&server->req_lock);
576 if (server->tcpStatus == CifsExiting) {
577 spin_unlock(&server->req_lock);
582 * For normal commands, reserve the last MAX_COMPOUND
583 * credits to compound requests.
584 * Otherwise these compounds could be permanently
585 * starved for credits by single-credit requests.
587 * To prevent spinning CPU, block this thread until
588 * there are >MAX_COMPOUND credits available.
589 * But only do this is we already have a lot of
590 * credits in flight to avoid triggering this check
591 * for servers that are slow to hand out credits on
594 if (!optype && num_credits == 1 &&
595 server->in_flight > 2 * MAX_COMPOUND &&
596 *credits <= MAX_COMPOUND) {
597 spin_unlock(&server->req_lock);
598 cifs_num_waiters_inc(server);
599 rc = wait_event_killable_timeout(
601 has_credits(server, credits,
604 cifs_num_waiters_dec(server);
606 trace_smb3_credit_timeout(
608 server->hostname, num_credits,
610 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
614 if (rc == -ERESTARTSYS)
616 spin_lock(&server->req_lock);
621 * Can not count locking commands against total
622 * as they are allowed to block on server.
625 /* update # of requests on the wire to server */
626 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
627 *credits -= num_credits;
629 server->in_flight += num_credits;
630 if (server->in_flight > server->max_in_flight)
631 server->max_in_flight = server->in_flight;
632 *instance = server->reconnect_instance;
634 spin_unlock(&server->req_lock);
636 trace_smb3_add_credits(server->CurrentMid,
637 server->hostname, scredits, -(num_credits));
638 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
639 __func__, num_credits, scredits);
647 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
648 unsigned int *instance)
650 return wait_for_free_credits(server, 1, -1, flags,
655 wait_for_compound_request(struct TCP_Server_Info *server, int num,
656 const int flags, unsigned int *instance)
659 int scredits, sin_flight;
661 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
663 spin_lock(&server->req_lock);
665 sin_flight = server->in_flight;
667 if (*credits < num) {
669 * If the server is tight on resources or just gives us less
670 * credits for other reasons (e.g. requests are coming out of
671 * order and the server delays granting more credits until it
672 * processes a missing mid) and we exhausted most available
673 * credits there may be situations when we try to send
674 * a compound request but we don't have enough credits. At this
675 * point the client needs to decide if it should wait for
676 * additional credits or fail the request. If at least one
677 * request is in flight there is a high probability that the
678 * server will return enough credits to satisfy this compound
681 * Return immediately if no requests in flight since we will be
682 * stuck on waiting for credits.
684 if (server->in_flight == 0) {
685 spin_unlock(&server->req_lock);
686 trace_smb3_insufficient_credits(server->CurrentMid,
687 server->hostname, scredits, sin_flight);
688 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
689 __func__, sin_flight, num, scredits);
693 spin_unlock(&server->req_lock);
695 return wait_for_free_credits(server, num, 60000, flags,
700 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
701 unsigned int *num, struct cifs_credits *credits)
705 credits->instance = server->reconnect_instance;
709 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
710 struct mid_q_entry **ppmidQ)
712 if (ses->server->tcpStatus == CifsExiting) {
716 if (ses->server->tcpStatus == CifsNeedReconnect) {
717 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
721 if (ses->status == CifsNew) {
722 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
723 (in_buf->Command != SMB_COM_NEGOTIATE))
725 /* else ok - we are setting up session */
728 if (ses->status == CifsExiting) {
729 /* check if SMB session is bad because we are setting it up */
730 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
732 /* else ok - we are shutting down session */
735 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
738 spin_lock(&GlobalMid_Lock);
739 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
740 spin_unlock(&GlobalMid_Lock);
745 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
749 error = wait_event_freezekillable_unsafe(server->response_q,
750 midQ->mid_state != MID_REQUEST_SUBMITTED);
758 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
761 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
762 struct mid_q_entry *mid;
764 if (rqst->rq_iov[0].iov_len != 4 ||
765 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
766 return ERR_PTR(-EIO);
768 /* enable signing if server requires it */
770 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
772 mid = AllocMidQEntry(hdr, server);
774 return ERR_PTR(-ENOMEM);
776 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
778 DeleteMidQEntry(mid);
786 * Send a SMB request and set the callback function in the mid to handle
787 * the result. Caller is responsible for dealing with timeouts.
790 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
791 mid_receive_t *receive, mid_callback_t *callback,
792 mid_handle_t *handle, void *cbdata, const int flags,
793 const struct cifs_credits *exist_credits)
796 struct mid_q_entry *mid;
797 struct cifs_credits credits = { .value = 0, .instance = 0 };
798 unsigned int instance;
801 optype = flags & CIFS_OP_MASK;
803 if ((flags & CIFS_HAS_CREDITS) == 0) {
804 rc = wait_for_free_request(server, flags, &instance);
808 credits.instance = instance;
810 instance = exist_credits->instance;
812 mutex_lock(&server->srv_mutex);
815 * We can't use credits obtained from the previous session to send this
816 * request. Check if there were reconnects after we obtained credits and
817 * return -EAGAIN in such cases to let callers handle it.
819 if (instance != server->reconnect_instance) {
820 mutex_unlock(&server->srv_mutex);
821 add_credits_and_wake_if(server, &credits, optype);
825 mid = server->ops->setup_async_request(server, rqst);
827 mutex_unlock(&server->srv_mutex);
828 add_credits_and_wake_if(server, &credits, optype);
832 mid->receive = receive;
833 mid->callback = callback;
834 mid->callback_data = cbdata;
835 mid->handle = handle;
836 mid->mid_state = MID_REQUEST_SUBMITTED;
838 /* put it on the pending_mid_q */
839 spin_lock(&GlobalMid_Lock);
840 list_add_tail(&mid->qhead, &server->pending_mid_q);
841 spin_unlock(&GlobalMid_Lock);
844 * Need to store the time in mid before calling I/O. For call_async,
845 * I/O response may come back and free the mid entry on another thread.
847 cifs_save_when_sent(mid);
848 cifs_in_send_inc(server);
849 rc = smb_send_rqst(server, 1, rqst, flags);
850 cifs_in_send_dec(server);
853 revert_current_mid(server, mid->credits);
854 server->sequence_number -= 2;
855 cifs_delete_mid(mid);
858 mutex_unlock(&server->srv_mutex);
863 add_credits_and_wake_if(server, &credits, optype);
869 * Send an SMB Request. No response info (other than return code)
870 * needs to be parsed.
872 * flags indicate the type of request buffer and how long to wait
873 * and whether to log NT STATUS code (error) before mapping it to POSIX error
877 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
878 char *in_buf, int flags)
885 iov[0].iov_base = in_buf;
886 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
887 flags |= CIFS_NO_RSP_BUF;
888 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
889 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
895 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
899 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
900 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
902 spin_lock(&GlobalMid_Lock);
903 switch (mid->mid_state) {
904 case MID_RESPONSE_RECEIVED:
905 spin_unlock(&GlobalMid_Lock);
907 case MID_RETRY_NEEDED:
910 case MID_RESPONSE_MALFORMED:
917 if (!(mid->mid_flags & MID_DELETED)) {
918 list_del_init(&mid->qhead);
919 mid->mid_flags |= MID_DELETED;
921 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
922 __func__, mid->mid, mid->mid_state);
925 spin_unlock(&GlobalMid_Lock);
927 DeleteMidQEntry(mid);
932 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
933 struct mid_q_entry *mid)
935 return server->ops->send_cancel ?
936 server->ops->send_cancel(server, rqst, mid) : 0;
940 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
943 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
945 dump_smb(mid->resp_buf, min_t(u32, 92, len));
947 /* convert the length into a more usable form */
951 struct smb_rqst rqst = { .rq_iov = iov,
954 iov[0].iov_base = mid->resp_buf;
956 iov[1].iov_base = (char *)mid->resp_buf + 4;
957 iov[1].iov_len = len - 4;
958 /* FIXME: add code to kill session */
959 rc = cifs_verify_signature(&rqst, server,
960 mid->sequence_number);
962 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
966 /* BB special case reconnect tid and uid here? */
967 return map_and_check_smb_error(mid, log_error);
971 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
972 struct smb_rqst *rqst)
975 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
976 struct mid_q_entry *mid;
978 if (rqst->rq_iov[0].iov_len != 4 ||
979 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
980 return ERR_PTR(-EIO);
982 rc = allocate_mid(ses, hdr, &mid);
985 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
987 cifs_delete_mid(mid);
994 cifs_compound_callback(struct mid_q_entry *mid)
996 struct TCP_Server_Info *server = mid->server;
997 struct cifs_credits credits;
999 credits.value = server->ops->get_credits(mid);
1000 credits.instance = server->reconnect_instance;
1002 add_credits(server, &credits, mid->optype);
1006 cifs_compound_last_callback(struct mid_q_entry *mid)
1008 cifs_compound_callback(mid);
1009 cifs_wake_up_task(mid);
1013 cifs_cancelled_callback(struct mid_q_entry *mid)
1015 cifs_compound_callback(mid);
1016 DeleteMidQEntry(mid);
1020 * Return a channel (master if none) of @ses that can be used to send
1023 * If we are currently binding a new channel (negprot/sess.setup),
1024 * return the new incomplete channel.
1026 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1033 if (!ses->binding) {
1035 if (ses->chan_count > 1) {
1036 index = (uint)atomic_inc_return(&ses->chan_seq);
1037 index %= ses->chan_count;
1039 return ses->chans[index].server;
1041 return cifs_ses_server(ses);
1046 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1047 struct TCP_Server_Info *server,
1048 const int flags, const int num_rqst, struct smb_rqst *rqst,
1049 int *resp_buf_type, struct kvec *resp_iov)
1051 int i, j, optype, rc = 0;
1052 struct mid_q_entry *midQ[MAX_COMPOUND];
1053 bool cancelled_mid[MAX_COMPOUND] = {false};
1054 struct cifs_credits credits[MAX_COMPOUND] = {
1055 { .value = 0, .instance = 0 }
1057 unsigned int instance;
1060 optype = flags & CIFS_OP_MASK;
1062 for (i = 0; i < num_rqst; i++)
1063 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1065 if (!ses || !ses->server || !server) {
1066 cifs_dbg(VFS, "Null session\n");
1070 if (server->tcpStatus == CifsExiting)
1074 * Wait for all the requests to become available.
1075 * This approach still leaves the possibility to be stuck waiting for
1076 * credits if the server doesn't grant credits to the outstanding
1077 * requests and if the client is completely idle, not generating any
1079 * This can be handled by the eventual session reconnect.
1081 rc = wait_for_compound_request(server, num_rqst, flags,
1086 for (i = 0; i < num_rqst; i++) {
1087 credits[i].value = 1;
1088 credits[i].instance = instance;
1092 * Make sure that we sign in the same order that we send on this socket
1093 * and avoid races inside tcp sendmsg code that could cause corruption
1097 mutex_lock(&server->srv_mutex);
1100 * All the parts of the compound chain belong obtained credits from the
1101 * same session. We can not use credits obtained from the previous
1102 * session to send this request. Check if there were reconnects after
1103 * we obtained credits and return -EAGAIN in such cases to let callers
1106 if (instance != server->reconnect_instance) {
1107 mutex_unlock(&server->srv_mutex);
1108 for (j = 0; j < num_rqst; j++)
1109 add_credits(server, &credits[j], optype);
1113 for (i = 0; i < num_rqst; i++) {
1114 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1115 if (IS_ERR(midQ[i])) {
1116 revert_current_mid(server, i);
1117 for (j = 0; j < i; j++)
1118 cifs_delete_mid(midQ[j]);
1119 mutex_unlock(&server->srv_mutex);
1121 /* Update # of requests on wire to server */
1122 for (j = 0; j < num_rqst; j++)
1123 add_credits(server, &credits[j], optype);
1124 return PTR_ERR(midQ[i]);
1127 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1128 midQ[i]->optype = optype;
1130 * Invoke callback for every part of the compound chain
1131 * to calculate credits properly. Wake up this thread only when
1132 * the last element is received.
1134 if (i < num_rqst - 1)
1135 midQ[i]->callback = cifs_compound_callback;
1137 midQ[i]->callback = cifs_compound_last_callback;
1139 cifs_in_send_inc(server);
1140 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1141 cifs_in_send_dec(server);
1143 for (i = 0; i < num_rqst; i++)
1144 cifs_save_when_sent(midQ[i]);
1147 revert_current_mid(server, num_rqst);
1148 server->sequence_number -= 2;
1151 mutex_unlock(&server->srv_mutex);
1154 * If sending failed for some reason or it is an oplock break that we
1155 * will not receive a response to - return credits back
1157 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1158 for (i = 0; i < num_rqst; i++)
1159 add_credits(server, &credits[i], optype);
1164 * At this point the request is passed to the network stack - we assume
1165 * that any credits taken from the server structure on the client have
1166 * been spent and we can't return them back. Once we receive responses
1167 * we will collect credits granted by the server in the mid callbacks
1168 * and add those credits to the server structure.
1172 * Compounding is never used during session establish.
1174 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
1175 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1178 for (i = 0; i < num_rqst; i++) {
1179 rc = wait_for_response(server, midQ[i]);
1184 for (; i < num_rqst; i++) {
1185 cifs_server_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n",
1186 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1187 send_cancel(server, &rqst[i], midQ[i]);
1188 spin_lock(&GlobalMid_Lock);
1189 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1190 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1191 midQ[i]->callback = cifs_cancelled_callback;
1192 cancelled_mid[i] = true;
1193 credits[i].value = 0;
1195 spin_unlock(&GlobalMid_Lock);
1199 for (i = 0; i < num_rqst; i++) {
1203 rc = cifs_sync_mid_result(midQ[i], server);
1205 /* mark this mid as cancelled to not free it below */
1206 cancelled_mid[i] = true;
1210 if (!midQ[i]->resp_buf ||
1211 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1213 cifs_dbg(FYI, "Bad MID state?\n");
1217 buf = (char *)midQ[i]->resp_buf;
1218 resp_iov[i].iov_base = buf;
1219 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1220 server->vals->header_preamble_size;
1222 if (midQ[i]->large_buf)
1223 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1225 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1227 rc = server->ops->check_receive(midQ[i], server,
1228 flags & CIFS_LOG_ERROR);
1230 /* mark it so buf will not be freed by cifs_delete_mid */
1231 if ((flags & CIFS_NO_RSP_BUF) == 0)
1232 midQ[i]->resp_buf = NULL;
1237 * Compounding is never used during session establish.
1239 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
1241 .iov_base = resp_iov[0].iov_base,
1242 .iov_len = resp_iov[0].iov_len
1244 smb311_update_preauth_hash(ses, &iov, 1);
1249 * This will dequeue all mids. After this it is important that the
1250 * demultiplex_thread will not process any of these mids any futher.
1251 * This is prevented above by using a noop callback that will not
1252 * wake this thread except for the very last PDU.
1254 for (i = 0; i < num_rqst; i++) {
1255 if (!cancelled_mid[i])
1256 cifs_delete_mid(midQ[i]);
1263 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1264 struct TCP_Server_Info *server,
1265 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1266 struct kvec *resp_iov)
1268 return compound_send_recv(xid, ses, server, flags, 1,
1269 rqst, resp_buf_type, resp_iov);
1273 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1274 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1275 const int flags, struct kvec *resp_iov)
1277 struct smb_rqst rqst;
1278 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1281 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1282 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1285 /* otherwise cifs_send_recv below sets resp_buf_type */
1286 *resp_buf_type = CIFS_NO_BUFFER;
1292 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1293 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1295 new_iov[0].iov_base = new_iov[1].iov_base;
1296 new_iov[0].iov_len = 4;
1297 new_iov[1].iov_base += 4;
1298 new_iov[1].iov_len -= 4;
1300 memset(&rqst, 0, sizeof(struct smb_rqst));
1301 rqst.rq_iov = new_iov;
1302 rqst.rq_nvec = n_vec + 1;
1304 rc = cifs_send_recv(xid, ses, ses->server,
1305 &rqst, resp_buf_type, flags, resp_iov);
1306 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1312 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1313 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1314 int *pbytes_returned, const int flags)
1317 struct mid_q_entry *midQ;
1318 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1319 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1320 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1321 struct cifs_credits credits = { .value = 1, .instance = 0 };
1322 struct TCP_Server_Info *server;
1325 cifs_dbg(VFS, "Null smb session\n");
1328 server = ses->server;
1329 if (server == NULL) {
1330 cifs_dbg(VFS, "Null tcp session\n");
1334 if (server->tcpStatus == CifsExiting)
1337 /* Ensure that we do not send more than 50 overlapping requests
1338 to the same server. We may make this configurable later or
1341 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1342 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1347 rc = wait_for_free_request(server, flags, &credits.instance);
1351 /* make sure that we sign in the same order that we send on this socket
1352 and avoid races inside tcp sendmsg code that could cause corruption
1355 mutex_lock(&server->srv_mutex);
1357 rc = allocate_mid(ses, in_buf, &midQ);
1359 mutex_unlock(&server->srv_mutex);
1360 /* Update # of requests on wire to server */
1361 add_credits(server, &credits, 0);
1365 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1367 mutex_unlock(&server->srv_mutex);
1371 midQ->mid_state = MID_REQUEST_SUBMITTED;
1373 cifs_in_send_inc(server);
1374 rc = smb_send(server, in_buf, len);
1375 cifs_in_send_dec(server);
1376 cifs_save_when_sent(midQ);
1379 server->sequence_number -= 2;
1381 mutex_unlock(&server->srv_mutex);
1386 rc = wait_for_response(server, midQ);
1388 send_cancel(server, &rqst, midQ);
1389 spin_lock(&GlobalMid_Lock);
1390 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1391 /* no longer considered to be "in-flight" */
1392 midQ->callback = DeleteMidQEntry;
1393 spin_unlock(&GlobalMid_Lock);
1394 add_credits(server, &credits, 0);
1397 spin_unlock(&GlobalMid_Lock);
1400 rc = cifs_sync_mid_result(midQ, server);
1402 add_credits(server, &credits, 0);
1406 if (!midQ->resp_buf || !out_buf ||
1407 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1409 cifs_server_dbg(VFS, "Bad MID state?\n");
1413 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1414 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1415 rc = cifs_check_receive(midQ, server, 0);
1417 cifs_delete_mid(midQ);
1418 add_credits(server, &credits, 0);
1423 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1424 blocking lock to return. */
1427 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1428 struct smb_hdr *in_buf,
1429 struct smb_hdr *out_buf)
1432 struct cifs_ses *ses = tcon->ses;
1433 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1435 /* We just modify the current in_buf to change
1436 the type of lock from LOCKING_ANDX_SHARED_LOCK
1437 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1438 LOCKING_ANDX_CANCEL_LOCK. */
1440 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1442 pSMB->hdr.Mid = get_next_mid(ses->server);
1444 return SendReceive(xid, ses, in_buf, out_buf,
1445 &bytes_returned, 0);
1449 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1450 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1451 int *pbytes_returned)
1455 struct mid_q_entry *midQ;
1456 struct cifs_ses *ses;
1457 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1458 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1459 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1460 unsigned int instance;
1461 struct TCP_Server_Info *server;
1463 if (tcon == NULL || tcon->ses == NULL) {
1464 cifs_dbg(VFS, "Null smb session\n");
1468 server = ses->server;
1470 if (server == NULL) {
1471 cifs_dbg(VFS, "Null tcp session\n");
1475 if (server->tcpStatus == CifsExiting)
1478 /* Ensure that we do not send more than 50 overlapping requests
1479 to the same server. We may make this configurable later or
1482 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1483 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1488 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1492 /* make sure that we sign in the same order that we send on this socket
1493 and avoid races inside tcp sendmsg code that could cause corruption
1496 mutex_lock(&server->srv_mutex);
1498 rc = allocate_mid(ses, in_buf, &midQ);
1500 mutex_unlock(&server->srv_mutex);
1504 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1506 cifs_delete_mid(midQ);
1507 mutex_unlock(&server->srv_mutex);
1511 midQ->mid_state = MID_REQUEST_SUBMITTED;
1512 cifs_in_send_inc(server);
1513 rc = smb_send(server, in_buf, len);
1514 cifs_in_send_dec(server);
1515 cifs_save_when_sent(midQ);
1518 server->sequence_number -= 2;
1520 mutex_unlock(&server->srv_mutex);
1523 cifs_delete_mid(midQ);
1527 /* Wait for a reply - allow signals to interrupt. */
1528 rc = wait_event_interruptible(server->response_q,
1529 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1530 ((server->tcpStatus != CifsGood) &&
1531 (server->tcpStatus != CifsNew)));
1533 /* Were we interrupted by a signal ? */
1534 if ((rc == -ERESTARTSYS) &&
1535 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1536 ((server->tcpStatus == CifsGood) ||
1537 (server->tcpStatus == CifsNew))) {
1539 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1540 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1541 blocking lock to return. */
1542 rc = send_cancel(server, &rqst, midQ);
1544 cifs_delete_mid(midQ);
1548 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1549 to cause the blocking lock to return. */
1551 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1553 /* If we get -ENOLCK back the lock may have
1554 already been removed. Don't exit in this case. */
1555 if (rc && rc != -ENOLCK) {
1556 cifs_delete_mid(midQ);
1561 rc = wait_for_response(server, midQ);
1563 send_cancel(server, &rqst, midQ);
1564 spin_lock(&GlobalMid_Lock);
1565 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1566 /* no longer considered to be "in-flight" */
1567 midQ->callback = DeleteMidQEntry;
1568 spin_unlock(&GlobalMid_Lock);
1571 spin_unlock(&GlobalMid_Lock);
1574 /* We got the response - restart system call. */
1578 rc = cifs_sync_mid_result(midQ, server);
1582 /* rcvd frame is ok */
1583 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1585 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1589 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1590 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1591 rc = cifs_check_receive(midQ, server, 0);
1593 cifs_delete_mid(midQ);
1594 if (rstart && rc == -EACCES)
1595 return -ERESTARTSYS;