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, 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 if (server->noblocksnd)
213 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
215 smb_msg->msg_flags = MSG_NOSIGNAL;
217 while (msg_data_left(smb_msg)) {
219 * If blocking send, we try 3 times, since each can block
220 * for 5 seconds. For nonblocking we have to try more
221 * but wait increasing amounts of time allowing time for
222 * socket to clear. The overall time we wait in either
223 * case to send on the socket is about 15 seconds.
224 * Similarly we wait for 15 seconds for a response from
225 * the server in SendReceive[2] for the server to send
226 * a response back for most types of requests (except
227 * SMB Write past end of file which can be slow, and
228 * blocking lock operations). NFS waits slightly longer
229 * than CIFS, but this can make it take longer for
230 * nonresponsive servers to be detected and 15 seconds
231 * is more than enough time for modern networks to
232 * send a packet. In most cases if we fail to send
233 * after the retries we will kill the socket and
234 * reconnect which may clear the network problem.
236 rc = sock_sendmsg(ssocket, smb_msg);
240 (!server->noblocksnd && (retries > 2))) {
241 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
245 msleep(1 << retries);
253 /* should never happen, letting socket clear before
254 retrying is our only obvious option here */
255 cifs_server_dbg(VFS, "tcp sent no data\n");
260 /* send was at least partially successful */
262 retries = 0; /* in case we get ENOSPC on the next send */
268 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
273 unsigned long buflen = 0;
275 if (server->vals->header_preamble_size == 0 &&
276 rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
277 iov = &rqst->rq_iov[1];
278 nvec = rqst->rq_nvec - 1;
281 nvec = rqst->rq_nvec;
284 /* total up iov array first */
285 for (i = 0; i < nvec; i++)
286 buflen += iov[i].iov_len;
289 * Add in the page array if there is one. The caller needs to make
290 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
291 * multiple pages ends at page boundary, rq_tailsz needs to be set to
294 if (rqst->rq_npages) {
295 if (rqst->rq_npages == 1)
296 buflen += rqst->rq_tailsz;
299 * If there is more than one page, calculate the
300 * buffer length based on rq_offset and rq_tailsz
302 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
304 buflen += rqst->rq_tailsz;
312 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
313 struct smb_rqst *rqst)
318 unsigned int send_length = 0;
320 sigset_t mask, oldmask;
321 size_t total_len = 0, sent, size;
322 struct socket *ssocket = server->ssocket;
323 struct msghdr smb_msg = {};
324 __be32 rfc1002_marker;
326 if (cifs_rdma_enabled(server)) {
327 /* return -EAGAIN when connecting or reconnecting */
329 if (server->smbd_conn)
330 rc = smbd_send(server, num_rqst, rqst);
337 if (fatal_signal_pending(current)) {
338 cifs_dbg(FYI, "signal pending before send request\n");
342 /* cork the socket */
343 tcp_sock_set_cork(ssocket->sk, true);
345 for (j = 0; j < num_rqst; j++)
346 send_length += smb_rqst_len(server, &rqst[j]);
347 rfc1002_marker = cpu_to_be32(send_length);
350 * We should not allow signals to interrupt the network send because
351 * any partial send will cause session reconnects thus increasing
352 * latency of system calls and overload a server with unnecessary
357 sigprocmask(SIG_BLOCK, &mask, &oldmask);
359 /* Generate a rfc1002 marker for SMB2+ */
360 if (server->vals->header_preamble_size == 0) {
362 .iov_base = &rfc1002_marker,
365 iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
366 rc = smb_send_kvec(server, &smb_msg, &sent);
374 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
376 for (j = 0; j < num_rqst; j++) {
377 iov = rqst[j].rq_iov;
378 n_vec = rqst[j].rq_nvec;
381 for (i = 0; i < n_vec; i++) {
382 dump_smb(iov[i].iov_base, iov[i].iov_len);
383 size += iov[i].iov_len;
386 iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
388 rc = smb_send_kvec(server, &smb_msg, &sent);
394 /* now walk the page array and send each page in it */
395 for (i = 0; i < rqst[j].rq_npages; i++) {
398 bvec.bv_page = rqst[j].rq_pages[i];
399 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
402 iov_iter_bvec(&smb_msg.msg_iter, WRITE,
403 &bvec, 1, bvec.bv_len);
404 rc = smb_send_kvec(server, &smb_msg, &sent);
413 sigprocmask(SIG_SETMASK, &oldmask, NULL);
416 * If signal is pending but we have already sent the whole packet to
417 * the server we need to return success status to allow a corresponding
418 * mid entry to be kept in the pending requests queue thus allowing
419 * to handle responses from the server by the client.
421 * If only part of the packet has been sent there is no need to hide
422 * interrupt because the session will be reconnected anyway, so there
423 * won't be any response from the server to handle.
426 if (signal_pending(current) && (total_len != send_length)) {
427 cifs_dbg(FYI, "signal is pending after attempt to send\n");
432 tcp_sock_set_cork(ssocket->sk, false);
434 if ((total_len > 0) && (total_len != send_length)) {
435 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
436 send_length, total_len);
438 * If we have only sent part of an SMB then the next SMB could
439 * be taken as the remainder of this one. We need to kill the
440 * socket so the server throws away the partial SMB
442 server->tcpStatus = CifsNeedReconnect;
443 trace_smb3_partial_send_reconnect(server->CurrentMid,
447 if (rc < 0 && rc != -EINTR)
448 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
457 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
458 struct smb_rqst *rqst, int flags)
461 struct smb2_transform_hdr *tr_hdr;
462 struct smb_rqst cur_rqst[MAX_COMPOUND];
465 if (!(flags & CIFS_TRANSFORM_REQ))
466 return __smb_send_rqst(server, num_rqst, rqst);
468 if (num_rqst > MAX_COMPOUND - 1)
471 if (!server->ops->init_transform_rq) {
472 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
476 tr_hdr = kmalloc(sizeof(*tr_hdr), GFP_NOFS);
480 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
481 memset(&iov, 0, sizeof(iov));
482 memset(tr_hdr, 0, sizeof(*tr_hdr));
484 iov.iov_base = tr_hdr;
485 iov.iov_len = sizeof(*tr_hdr);
486 cur_rqst[0].rq_iov = &iov;
487 cur_rqst[0].rq_nvec = 1;
489 rc = server->ops->init_transform_rq(server, num_rqst + 1,
494 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
495 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
502 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
503 unsigned int smb_buf_length)
506 struct smb_rqst rqst = { .rq_iov = iov,
509 iov[0].iov_base = smb_buffer;
511 iov[1].iov_base = (char *)smb_buffer + 4;
512 iov[1].iov_len = smb_buf_length;
514 return __smb_send_rqst(server, 1, &rqst);
518 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
519 const int timeout, const int flags,
520 unsigned int *instance)
528 t = MAX_JIFFY_OFFSET;
530 t = msecs_to_jiffies(timeout);
532 optype = flags & CIFS_OP_MASK;
536 credits = server->ops->get_credits_field(server, optype);
537 /* Since an echo is already inflight, no need to wait to send another */
538 if (*credits <= 0 && optype == CIFS_ECHO_OP)
541 spin_lock(&server->req_lock);
542 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
543 /* oplock breaks must not be held up */
545 if (server->in_flight > server->max_in_flight)
546 server->max_in_flight = server->in_flight;
548 *instance = server->reconnect_instance;
549 spin_unlock(&server->req_lock);
554 if (*credits < num_credits) {
555 spin_unlock(&server->req_lock);
556 cifs_num_waiters_inc(server);
557 rc = wait_event_killable_timeout(server->request_q,
558 has_credits(server, credits, num_credits), t);
559 cifs_num_waiters_dec(server);
561 trace_smb3_credit_timeout(server->CurrentMid,
562 server->hostname, num_credits, 0);
563 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
567 if (rc == -ERESTARTSYS)
569 spin_lock(&server->req_lock);
571 if (server->tcpStatus == CifsExiting) {
572 spin_unlock(&server->req_lock);
577 * For normal commands, reserve the last MAX_COMPOUND
578 * credits to compound requests.
579 * Otherwise these compounds could be permanently
580 * starved for credits by single-credit requests.
582 * To prevent spinning CPU, block this thread until
583 * there are >MAX_COMPOUND credits available.
584 * But only do this is we already have a lot of
585 * credits in flight to avoid triggering this check
586 * for servers that are slow to hand out credits on
589 if (!optype && num_credits == 1 &&
590 server->in_flight > 2 * MAX_COMPOUND &&
591 *credits <= MAX_COMPOUND) {
592 spin_unlock(&server->req_lock);
593 cifs_num_waiters_inc(server);
594 rc = wait_event_killable_timeout(
596 has_credits(server, credits,
599 cifs_num_waiters_dec(server);
601 trace_smb3_credit_timeout(
603 server->hostname, num_credits,
605 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
609 if (rc == -ERESTARTSYS)
611 spin_lock(&server->req_lock);
616 * Can not count locking commands against total
617 * as they are allowed to block on server.
620 /* update # of requests on the wire to server */
621 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
622 *credits -= num_credits;
623 server->in_flight += num_credits;
624 if (server->in_flight > server->max_in_flight)
625 server->max_in_flight = server->in_flight;
626 *instance = server->reconnect_instance;
628 spin_unlock(&server->req_lock);
636 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
637 unsigned int *instance)
639 return wait_for_free_credits(server, 1, -1, flags,
644 wait_for_compound_request(struct TCP_Server_Info *server, int num,
645 const int flags, unsigned int *instance)
649 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
651 spin_lock(&server->req_lock);
652 if (*credits < num) {
654 * If the server is tight on resources or just gives us less
655 * credits for other reasons (e.g. requests are coming out of
656 * order and the server delays granting more credits until it
657 * processes a missing mid) and we exhausted most available
658 * credits there may be situations when we try to send
659 * a compound request but we don't have enough credits. At this
660 * point the client needs to decide if it should wait for
661 * additional credits or fail the request. If at least one
662 * request is in flight there is a high probability that the
663 * server will return enough credits to satisfy this compound
666 * Return immediately if no requests in flight since we will be
667 * stuck on waiting for credits.
669 if (server->in_flight == 0) {
670 spin_unlock(&server->req_lock);
674 spin_unlock(&server->req_lock);
676 return wait_for_free_credits(server, num, 60000, flags,
681 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
682 unsigned int *num, struct cifs_credits *credits)
686 credits->instance = server->reconnect_instance;
690 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
691 struct mid_q_entry **ppmidQ)
693 if (ses->server->tcpStatus == CifsExiting) {
697 if (ses->server->tcpStatus == CifsNeedReconnect) {
698 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
702 if (ses->status == CifsNew) {
703 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
704 (in_buf->Command != SMB_COM_NEGOTIATE))
706 /* else ok - we are setting up session */
709 if (ses->status == CifsExiting) {
710 /* check if SMB session is bad because we are setting it up */
711 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
713 /* else ok - we are shutting down session */
716 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
719 spin_lock(&GlobalMid_Lock);
720 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
721 spin_unlock(&GlobalMid_Lock);
726 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
730 error = wait_event_freezekillable_unsafe(server->response_q,
731 midQ->mid_state != MID_REQUEST_SUBMITTED);
739 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
742 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
743 struct mid_q_entry *mid;
745 if (rqst->rq_iov[0].iov_len != 4 ||
746 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
747 return ERR_PTR(-EIO);
749 /* enable signing if server requires it */
751 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
753 mid = AllocMidQEntry(hdr, server);
755 return ERR_PTR(-ENOMEM);
757 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
759 DeleteMidQEntry(mid);
767 * Send a SMB request and set the callback function in the mid to handle
768 * the result. Caller is responsible for dealing with timeouts.
771 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
772 mid_receive_t *receive, mid_callback_t *callback,
773 mid_handle_t *handle, void *cbdata, const int flags,
774 const struct cifs_credits *exist_credits)
777 struct mid_q_entry *mid;
778 struct cifs_credits credits = { .value = 0, .instance = 0 };
779 unsigned int instance;
782 optype = flags & CIFS_OP_MASK;
784 if ((flags & CIFS_HAS_CREDITS) == 0) {
785 rc = wait_for_free_request(server, flags, &instance);
789 credits.instance = instance;
791 instance = exist_credits->instance;
793 mutex_lock(&server->srv_mutex);
796 * We can't use credits obtained from the previous session to send this
797 * request. Check if there were reconnects after we obtained credits and
798 * return -EAGAIN in such cases to let callers handle it.
800 if (instance != server->reconnect_instance) {
801 mutex_unlock(&server->srv_mutex);
802 add_credits_and_wake_if(server, &credits, optype);
806 mid = server->ops->setup_async_request(server, rqst);
808 mutex_unlock(&server->srv_mutex);
809 add_credits_and_wake_if(server, &credits, optype);
813 mid->receive = receive;
814 mid->callback = callback;
815 mid->callback_data = cbdata;
816 mid->handle = handle;
817 mid->mid_state = MID_REQUEST_SUBMITTED;
819 /* put it on the pending_mid_q */
820 spin_lock(&GlobalMid_Lock);
821 list_add_tail(&mid->qhead, &server->pending_mid_q);
822 spin_unlock(&GlobalMid_Lock);
825 * Need to store the time in mid before calling I/O. For call_async,
826 * I/O response may come back and free the mid entry on another thread.
828 cifs_save_when_sent(mid);
829 cifs_in_send_inc(server);
830 rc = smb_send_rqst(server, 1, rqst, flags);
831 cifs_in_send_dec(server);
834 revert_current_mid(server, mid->credits);
835 server->sequence_number -= 2;
836 cifs_delete_mid(mid);
839 mutex_unlock(&server->srv_mutex);
844 add_credits_and_wake_if(server, &credits, optype);
850 * Send an SMB Request. No response info (other than return code)
851 * needs to be parsed.
853 * flags indicate the type of request buffer and how long to wait
854 * and whether to log NT STATUS code (error) before mapping it to POSIX error
858 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
859 char *in_buf, int flags)
866 iov[0].iov_base = in_buf;
867 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
868 flags |= CIFS_NO_RSP_BUF;
869 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
870 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
876 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
880 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
881 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
883 spin_lock(&GlobalMid_Lock);
884 switch (mid->mid_state) {
885 case MID_RESPONSE_RECEIVED:
886 spin_unlock(&GlobalMid_Lock);
888 case MID_RETRY_NEEDED:
891 case MID_RESPONSE_MALFORMED:
898 if (!(mid->mid_flags & MID_DELETED)) {
899 list_del_init(&mid->qhead);
900 mid->mid_flags |= MID_DELETED;
902 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
903 __func__, mid->mid, mid->mid_state);
906 spin_unlock(&GlobalMid_Lock);
908 DeleteMidQEntry(mid);
913 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
914 struct mid_q_entry *mid)
916 return server->ops->send_cancel ?
917 server->ops->send_cancel(server, rqst, mid) : 0;
921 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
924 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
926 dump_smb(mid->resp_buf, min_t(u32, 92, len));
928 /* convert the length into a more usable form */
932 struct smb_rqst rqst = { .rq_iov = iov,
935 iov[0].iov_base = mid->resp_buf;
937 iov[1].iov_base = (char *)mid->resp_buf + 4;
938 iov[1].iov_len = len - 4;
939 /* FIXME: add code to kill session */
940 rc = cifs_verify_signature(&rqst, server,
941 mid->sequence_number);
943 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
947 /* BB special case reconnect tid and uid here? */
948 return map_and_check_smb_error(mid, log_error);
952 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
953 struct smb_rqst *rqst)
956 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
957 struct mid_q_entry *mid;
959 if (rqst->rq_iov[0].iov_len != 4 ||
960 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
961 return ERR_PTR(-EIO);
963 rc = allocate_mid(ses, hdr, &mid);
966 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
968 cifs_delete_mid(mid);
975 cifs_compound_callback(struct mid_q_entry *mid)
977 struct TCP_Server_Info *server = mid->server;
978 struct cifs_credits credits;
980 credits.value = server->ops->get_credits(mid);
981 credits.instance = server->reconnect_instance;
983 add_credits(server, &credits, mid->optype);
987 cifs_compound_last_callback(struct mid_q_entry *mid)
989 cifs_compound_callback(mid);
990 cifs_wake_up_task(mid);
994 cifs_cancelled_callback(struct mid_q_entry *mid)
996 cifs_compound_callback(mid);
997 DeleteMidQEntry(mid);
1001 * Return a channel (master if none) of @ses that can be used to send
1004 * If we are currently binding a new channel (negprot/sess.setup),
1005 * return the new incomplete channel.
1007 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1014 if (!ses->binding) {
1016 if (ses->chan_count > 1) {
1017 index = (uint)atomic_inc_return(&ses->chan_seq);
1018 index %= ses->chan_count;
1020 return ses->chans[index].server;
1022 return cifs_ses_server(ses);
1027 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1028 struct TCP_Server_Info *server,
1029 const int flags, const int num_rqst, struct smb_rqst *rqst,
1030 int *resp_buf_type, struct kvec *resp_iov)
1032 int i, j, optype, rc = 0;
1033 struct mid_q_entry *midQ[MAX_COMPOUND];
1034 bool cancelled_mid[MAX_COMPOUND] = {false};
1035 struct cifs_credits credits[MAX_COMPOUND] = {
1036 { .value = 0, .instance = 0 }
1038 unsigned int instance;
1041 optype = flags & CIFS_OP_MASK;
1043 for (i = 0; i < num_rqst; i++)
1044 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1046 if (!ses || !ses->server || !server) {
1047 cifs_dbg(VFS, "Null session\n");
1051 if (server->tcpStatus == CifsExiting)
1055 * Wait for all the requests to become available.
1056 * This approach still leaves the possibility to be stuck waiting for
1057 * credits if the server doesn't grant credits to the outstanding
1058 * requests and if the client is completely idle, not generating any
1060 * This can be handled by the eventual session reconnect.
1062 rc = wait_for_compound_request(server, num_rqst, flags,
1067 for (i = 0; i < num_rqst; i++) {
1068 credits[i].value = 1;
1069 credits[i].instance = instance;
1073 * Make sure that we sign in the same order that we send on this socket
1074 * and avoid races inside tcp sendmsg code that could cause corruption
1078 mutex_lock(&server->srv_mutex);
1081 * All the parts of the compound chain belong obtained credits from the
1082 * same session. We can not use credits obtained from the previous
1083 * session to send this request. Check if there were reconnects after
1084 * we obtained credits and return -EAGAIN in such cases to let callers
1087 if (instance != server->reconnect_instance) {
1088 mutex_unlock(&server->srv_mutex);
1089 for (j = 0; j < num_rqst; j++)
1090 add_credits(server, &credits[j], optype);
1094 for (i = 0; i < num_rqst; i++) {
1095 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1096 if (IS_ERR(midQ[i])) {
1097 revert_current_mid(server, i);
1098 for (j = 0; j < i; j++)
1099 cifs_delete_mid(midQ[j]);
1100 mutex_unlock(&server->srv_mutex);
1102 /* Update # of requests on wire to server */
1103 for (j = 0; j < num_rqst; j++)
1104 add_credits(server, &credits[j], optype);
1105 return PTR_ERR(midQ[i]);
1108 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1109 midQ[i]->optype = optype;
1111 * Invoke callback for every part of the compound chain
1112 * to calculate credits properly. Wake up this thread only when
1113 * the last element is received.
1115 if (i < num_rqst - 1)
1116 midQ[i]->callback = cifs_compound_callback;
1118 midQ[i]->callback = cifs_compound_last_callback;
1120 cifs_in_send_inc(server);
1121 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1122 cifs_in_send_dec(server);
1124 for (i = 0; i < num_rqst; i++)
1125 cifs_save_when_sent(midQ[i]);
1128 revert_current_mid(server, num_rqst);
1129 server->sequence_number -= 2;
1132 mutex_unlock(&server->srv_mutex);
1135 * If sending failed for some reason or it is an oplock break that we
1136 * will not receive a response to - return credits back
1138 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1139 for (i = 0; i < num_rqst; i++)
1140 add_credits(server, &credits[i], optype);
1145 * At this point the request is passed to the network stack - we assume
1146 * that any credits taken from the server structure on the client have
1147 * been spent and we can't return them back. Once we receive responses
1148 * we will collect credits granted by the server in the mid callbacks
1149 * and add those credits to the server structure.
1153 * Compounding is never used during session establish.
1155 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
1156 mutex_lock(&server->srv_mutex);
1157 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1159 mutex_unlock(&server->srv_mutex);
1162 for (i = 0; i < num_rqst; i++) {
1163 rc = wait_for_response(server, midQ[i]);
1168 for (; i < num_rqst; i++) {
1169 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1170 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1171 send_cancel(server, &rqst[i], midQ[i]);
1172 spin_lock(&GlobalMid_Lock);
1173 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1174 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1175 midQ[i]->callback = cifs_cancelled_callback;
1176 cancelled_mid[i] = true;
1177 credits[i].value = 0;
1179 spin_unlock(&GlobalMid_Lock);
1183 for (i = 0; i < num_rqst; i++) {
1187 rc = cifs_sync_mid_result(midQ[i], server);
1189 /* mark this mid as cancelled to not free it below */
1190 cancelled_mid[i] = true;
1194 if (!midQ[i]->resp_buf ||
1195 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1197 cifs_dbg(FYI, "Bad MID state?\n");
1201 buf = (char *)midQ[i]->resp_buf;
1202 resp_iov[i].iov_base = buf;
1203 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1204 server->vals->header_preamble_size;
1206 if (midQ[i]->large_buf)
1207 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1209 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1211 rc = server->ops->check_receive(midQ[i], server,
1212 flags & CIFS_LOG_ERROR);
1214 /* mark it so buf will not be freed by cifs_delete_mid */
1215 if ((flags & CIFS_NO_RSP_BUF) == 0)
1216 midQ[i]->resp_buf = NULL;
1221 * Compounding is never used during session establish.
1223 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
1225 .iov_base = resp_iov[0].iov_base,
1226 .iov_len = resp_iov[0].iov_len
1228 mutex_lock(&server->srv_mutex);
1229 smb311_update_preauth_hash(ses, &iov, 1);
1230 mutex_unlock(&server->srv_mutex);
1235 * This will dequeue all mids. After this it is important that the
1236 * demultiplex_thread will not process any of these mids any futher.
1237 * This is prevented above by using a noop callback that will not
1238 * wake this thread except for the very last PDU.
1240 for (i = 0; i < num_rqst; i++) {
1241 if (!cancelled_mid[i])
1242 cifs_delete_mid(midQ[i]);
1249 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1250 struct TCP_Server_Info *server,
1251 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1252 struct kvec *resp_iov)
1254 return compound_send_recv(xid, ses, server, flags, 1,
1255 rqst, resp_buf_type, resp_iov);
1259 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1260 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1261 const int flags, struct kvec *resp_iov)
1263 struct smb_rqst rqst;
1264 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1267 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1268 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1271 /* otherwise cifs_send_recv below sets resp_buf_type */
1272 *resp_buf_type = CIFS_NO_BUFFER;
1278 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1279 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1281 new_iov[0].iov_base = new_iov[1].iov_base;
1282 new_iov[0].iov_len = 4;
1283 new_iov[1].iov_base += 4;
1284 new_iov[1].iov_len -= 4;
1286 memset(&rqst, 0, sizeof(struct smb_rqst));
1287 rqst.rq_iov = new_iov;
1288 rqst.rq_nvec = n_vec + 1;
1290 rc = cifs_send_recv(xid, ses, ses->server,
1291 &rqst, resp_buf_type, flags, resp_iov);
1292 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1298 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1299 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1300 int *pbytes_returned, const int flags)
1303 struct mid_q_entry *midQ;
1304 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1305 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1306 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1307 struct cifs_credits credits = { .value = 1, .instance = 0 };
1308 struct TCP_Server_Info *server;
1311 cifs_dbg(VFS, "Null smb session\n");
1314 server = ses->server;
1315 if (server == NULL) {
1316 cifs_dbg(VFS, "Null tcp session\n");
1320 if (server->tcpStatus == CifsExiting)
1323 /* Ensure that we do not send more than 50 overlapping requests
1324 to the same server. We may make this configurable later or
1327 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1328 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1333 rc = wait_for_free_request(server, flags, &credits.instance);
1337 /* make sure that we sign in the same order that we send on this socket
1338 and avoid races inside tcp sendmsg code that could cause corruption
1341 mutex_lock(&server->srv_mutex);
1343 rc = allocate_mid(ses, in_buf, &midQ);
1345 mutex_unlock(&server->srv_mutex);
1346 /* Update # of requests on wire to server */
1347 add_credits(server, &credits, 0);
1351 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1353 mutex_unlock(&server->srv_mutex);
1357 midQ->mid_state = MID_REQUEST_SUBMITTED;
1359 cifs_in_send_inc(server);
1360 rc = smb_send(server, in_buf, len);
1361 cifs_in_send_dec(server);
1362 cifs_save_when_sent(midQ);
1365 server->sequence_number -= 2;
1367 mutex_unlock(&server->srv_mutex);
1372 rc = wait_for_response(server, midQ);
1374 send_cancel(server, &rqst, midQ);
1375 spin_lock(&GlobalMid_Lock);
1376 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1377 /* no longer considered to be "in-flight" */
1378 midQ->callback = DeleteMidQEntry;
1379 spin_unlock(&GlobalMid_Lock);
1380 add_credits(server, &credits, 0);
1383 spin_unlock(&GlobalMid_Lock);
1386 rc = cifs_sync_mid_result(midQ, server);
1388 add_credits(server, &credits, 0);
1392 if (!midQ->resp_buf || !out_buf ||
1393 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1395 cifs_server_dbg(VFS, "Bad MID state?\n");
1399 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1400 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1401 rc = cifs_check_receive(midQ, server, 0);
1403 cifs_delete_mid(midQ);
1404 add_credits(server, &credits, 0);
1409 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1410 blocking lock to return. */
1413 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1414 struct smb_hdr *in_buf,
1415 struct smb_hdr *out_buf)
1418 struct cifs_ses *ses = tcon->ses;
1419 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1421 /* We just modify the current in_buf to change
1422 the type of lock from LOCKING_ANDX_SHARED_LOCK
1423 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1424 LOCKING_ANDX_CANCEL_LOCK. */
1426 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1428 pSMB->hdr.Mid = get_next_mid(ses->server);
1430 return SendReceive(xid, ses, in_buf, out_buf,
1431 &bytes_returned, 0);
1435 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1436 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1437 int *pbytes_returned)
1441 struct mid_q_entry *midQ;
1442 struct cifs_ses *ses;
1443 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1444 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1445 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1446 unsigned int instance;
1447 struct TCP_Server_Info *server;
1449 if (tcon == NULL || tcon->ses == NULL) {
1450 cifs_dbg(VFS, "Null smb session\n");
1454 server = ses->server;
1456 if (server == NULL) {
1457 cifs_dbg(VFS, "Null tcp session\n");
1461 if (server->tcpStatus == CifsExiting)
1464 /* Ensure that we do not send more than 50 overlapping requests
1465 to the same server. We may make this configurable later or
1468 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1469 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1474 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1478 /* make sure that we sign in the same order that we send on this socket
1479 and avoid races inside tcp sendmsg code that could cause corruption
1482 mutex_lock(&server->srv_mutex);
1484 rc = allocate_mid(ses, in_buf, &midQ);
1486 mutex_unlock(&server->srv_mutex);
1490 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1492 cifs_delete_mid(midQ);
1493 mutex_unlock(&server->srv_mutex);
1497 midQ->mid_state = MID_REQUEST_SUBMITTED;
1498 cifs_in_send_inc(server);
1499 rc = smb_send(server, in_buf, len);
1500 cifs_in_send_dec(server);
1501 cifs_save_when_sent(midQ);
1504 server->sequence_number -= 2;
1506 mutex_unlock(&server->srv_mutex);
1509 cifs_delete_mid(midQ);
1513 /* Wait for a reply - allow signals to interrupt. */
1514 rc = wait_event_interruptible(server->response_q,
1515 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1516 ((server->tcpStatus != CifsGood) &&
1517 (server->tcpStatus != CifsNew)));
1519 /* Were we interrupted by a signal ? */
1520 if ((rc == -ERESTARTSYS) &&
1521 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1522 ((server->tcpStatus == CifsGood) ||
1523 (server->tcpStatus == CifsNew))) {
1525 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1526 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1527 blocking lock to return. */
1528 rc = send_cancel(server, &rqst, midQ);
1530 cifs_delete_mid(midQ);
1534 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1535 to cause the blocking lock to return. */
1537 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1539 /* If we get -ENOLCK back the lock may have
1540 already been removed. Don't exit in this case. */
1541 if (rc && rc != -ENOLCK) {
1542 cifs_delete_mid(midQ);
1547 rc = wait_for_response(server, midQ);
1549 send_cancel(server, &rqst, midQ);
1550 spin_lock(&GlobalMid_Lock);
1551 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1552 /* no longer considered to be "in-flight" */
1553 midQ->callback = DeleteMidQEntry;
1554 spin_unlock(&GlobalMid_Lock);
1557 spin_unlock(&GlobalMid_Lock);
1560 /* We got the response - restart system call. */
1564 rc = cifs_sync_mid_result(midQ, server);
1568 /* rcvd frame is ok */
1569 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1571 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1575 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1576 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1577 rc = cifs_check_receive(midQ, server, 0);
1579 cifs_delete_mid(midQ);
1580 if (rstart && rc == -EACCES)
1581 return -ERESTARTSYS;