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>
38 #include "cifsproto.h"
39 #include "cifs_debug.h"
42 cifs_wake_up_task(struct mid_q_entry *mid)
44 wake_up_process(mid->callback_data);
48 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
50 struct mid_q_entry *temp;
53 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
57 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
61 memset(temp, 0, sizeof(struct mid_q_entry));
62 temp->mid = get_mid(smb_buffer);
63 temp->pid = current->pid;
64 temp->command = cpu_to_le16(smb_buffer->Command);
65 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
66 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
67 /* when mid allocated can be before when sent */
68 temp->when_alloc = jiffies;
69 temp->server = server;
72 * The default is for the mid to be synchronous, so the
73 * default callback just wakes up the current task.
75 temp->callback = cifs_wake_up_task;
76 temp->callback_data = current;
79 atomic_inc(&midCount);
80 temp->mid_state = MID_REQUEST_ALLOCATED;
85 DeleteMidQEntry(struct mid_q_entry *midEntry)
87 #ifdef CONFIG_CIFS_STATS2
88 __le16 command = midEntry->server->vals->lock_cmd;
91 midEntry->mid_state = MID_FREE;
92 atomic_dec(&midCount);
93 if (midEntry->large_buf)
94 cifs_buf_release(midEntry->resp_buf);
96 cifs_small_buf_release(midEntry->resp_buf);
97 #ifdef CONFIG_CIFS_STATS2
99 /* commands taking longer than one second are indications that
100 something is wrong, unless it is quite a slow link or server */
101 if ((now - midEntry->when_alloc) > HZ) {
102 if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) {
103 pr_debug(" CIFS slow rsp: cmd %d mid %llu",
104 midEntry->command, midEntry->mid);
105 pr_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
106 now - midEntry->when_alloc,
107 now - midEntry->when_sent,
108 now - midEntry->when_received);
112 mempool_free(midEntry, cifs_mid_poolp);
116 cifs_delete_mid(struct mid_q_entry *mid)
118 spin_lock(&GlobalMid_Lock);
119 list_del(&mid->qhead);
120 spin_unlock(&GlobalMid_Lock);
122 DeleteMidQEntry(mid);
126 * smb_send_kvec - send an array of kvecs to the server
127 * @server: Server to send the data to
128 * @smb_msg: Message to send
129 * @sent: amount of data sent on socket is stored here
131 * Our basic "send data to server" function. Should be called with srv_mutex
132 * held. The caller is responsible for handling the results.
135 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
140 struct socket *ssocket = server->ssocket;
144 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
145 smb_msg->msg_namelen = sizeof(struct sockaddr);
146 smb_msg->msg_control = NULL;
147 smb_msg->msg_controllen = 0;
148 if (server->noblocksnd)
149 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
151 smb_msg->msg_flags = MSG_NOSIGNAL;
153 while (msg_data_left(smb_msg)) {
155 * If blocking send, we try 3 times, since each can block
156 * for 5 seconds. For nonblocking we have to try more
157 * but wait increasing amounts of time allowing time for
158 * socket to clear. The overall time we wait in either
159 * case to send on the socket is about 15 seconds.
160 * Similarly we wait for 15 seconds for a response from
161 * the server in SendReceive[2] for the server to send
162 * a response back for most types of requests (except
163 * SMB Write past end of file which can be slow, and
164 * blocking lock operations). NFS waits slightly longer
165 * than CIFS, but this can make it take longer for
166 * nonresponsive servers to be detected and 15 seconds
167 * is more than enough time for modern networks to
168 * send a packet. In most cases if we fail to send
169 * after the retries we will kill the socket and
170 * reconnect which may clear the network problem.
172 rc = sock_sendmsg(ssocket, smb_msg);
176 (!server->noblocksnd && (retries > 2))) {
177 cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
181 msleep(1 << retries);
189 /* should never happen, letting socket clear before
190 retrying is our only obvious option here */
191 cifs_dbg(VFS, "tcp sent no data\n");
196 /* send was at least partially successful */
198 retries = 0; /* in case we get ENOSPC on the next send */
204 rqst_len(struct smb_rqst *rqst)
207 struct kvec *iov = rqst->rq_iov;
208 unsigned long buflen = 0;
210 /* total up iov array first */
211 for (i = 0; i < rqst->rq_nvec; i++)
212 buflen += iov[i].iov_len;
214 /* add in the page array if there is one */
215 if (rqst->rq_npages) {
216 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
217 buflen += rqst->rq_tailsz;
224 __smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
227 struct kvec *iov = rqst->rq_iov;
228 int n_vec = rqst->rq_nvec;
229 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
230 unsigned long send_length;
232 size_t total_len = 0, sent, size;
233 struct socket *ssocket = server->ssocket;
234 struct msghdr smb_msg;
240 /* sanity check send length */
241 send_length = rqst_len(rqst);
242 if (send_length != smb_buf_length + 4) {
243 WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
244 send_length, smb_buf_length);
251 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
252 dump_smb(iov[0].iov_base, iov[0].iov_len);
253 dump_smb(iov[1].iov_base, iov[1].iov_len);
255 /* cork the socket */
256 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
257 (char *)&val, sizeof(val));
260 for (i = 0; i < n_vec; i++)
261 size += iov[i].iov_len;
263 iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, iov, n_vec, size);
265 rc = smb_send_kvec(server, &smb_msg, &sent);
271 /* now walk the page array and send each page in it */
272 for (i = 0; i < rqst->rq_npages; i++) {
273 size_t len = i == rqst->rq_npages - 1
276 struct bio_vec bvec = {
277 .bv_page = rqst->rq_pages[i],
280 iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
282 rc = smb_send_kvec(server, &smb_msg, &sent);
292 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
293 (char *)&val, sizeof(val));
295 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
296 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
297 smb_buf_length + 4, total_len);
299 * If we have only sent part of an SMB then the next SMB could
300 * be taken as the remainder of this one. We need to kill the
301 * socket so the server throws away the partial SMB
303 server->tcpStatus = CifsNeedReconnect;
306 if (rc < 0 && rc != -EINTR)
307 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
316 smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst, int flags)
318 struct smb_rqst cur_rqst;
321 if (!(flags & CIFS_TRANSFORM_REQ))
322 return __smb_send_rqst(server, rqst);
324 if (!server->ops->init_transform_rq ||
325 !server->ops->free_transform_rq) {
326 cifs_dbg(VFS, "Encryption requested but transform callbacks are missed\n");
330 rc = server->ops->init_transform_rq(server, &cur_rqst, rqst);
334 rc = __smb_send_rqst(server, &cur_rqst);
335 server->ops->free_transform_rq(&cur_rqst);
340 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
341 unsigned int smb_buf_length)
344 struct smb_rqst rqst = { .rq_iov = iov,
347 iov[0].iov_base = smb_buffer;
349 iov[1].iov_base = (char *)smb_buffer + 4;
350 iov[1].iov_len = smb_buf_length;
352 return __smb_send_rqst(server, &rqst);
356 wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
361 spin_lock(&server->req_lock);
362 if (timeout == CIFS_ASYNC_OP) {
363 /* oplock breaks must not be held up */
366 spin_unlock(&server->req_lock);
372 spin_unlock(&server->req_lock);
373 cifs_num_waiters_inc(server);
374 rc = wait_event_killable(server->request_q,
375 has_credits(server, credits));
376 cifs_num_waiters_dec(server);
379 spin_lock(&server->req_lock);
381 if (server->tcpStatus == CifsExiting) {
382 spin_unlock(&server->req_lock);
387 * Can not count locking commands against total
388 * as they are allowed to block on server.
391 /* update # of requests on the wire to server */
392 if (timeout != CIFS_BLOCKING_OP) {
396 spin_unlock(&server->req_lock);
404 wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
409 val = server->ops->get_credits_field(server, optype);
410 /* Since an echo is already inflight, no need to wait to send another */
411 if (*val <= 0 && optype == CIFS_ECHO_OP)
413 return wait_for_free_credits(server, timeout, val);
417 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
418 unsigned int *num, unsigned int *credits)
425 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
426 struct mid_q_entry **ppmidQ)
428 if (ses->server->tcpStatus == CifsExiting) {
432 if (ses->server->tcpStatus == CifsNeedReconnect) {
433 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
437 if (ses->status == CifsNew) {
438 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
439 (in_buf->Command != SMB_COM_NEGOTIATE))
441 /* else ok - we are setting up session */
444 if (ses->status == CifsExiting) {
445 /* check if SMB session is bad because we are setting it up */
446 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
448 /* else ok - we are shutting down session */
451 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
454 spin_lock(&GlobalMid_Lock);
455 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
456 spin_unlock(&GlobalMid_Lock);
461 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
465 error = wait_event_freezekillable_unsafe(server->response_q,
466 midQ->mid_state != MID_REQUEST_SUBMITTED);
474 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
477 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
478 struct mid_q_entry *mid;
480 if (rqst->rq_iov[0].iov_len != 4 ||
481 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
482 return ERR_PTR(-EIO);
484 /* enable signing if server requires it */
486 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
488 mid = AllocMidQEntry(hdr, server);
490 return ERR_PTR(-ENOMEM);
492 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
494 DeleteMidQEntry(mid);
502 * Send a SMB request and set the callback function in the mid to handle
503 * the result. Caller is responsible for dealing with timeouts.
506 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
507 mid_receive_t *receive, mid_callback_t *callback,
508 mid_handle_t *handle, void *cbdata, const int flags)
510 int rc, timeout, optype;
511 struct mid_q_entry *mid;
512 unsigned int credits = 0;
514 timeout = flags & CIFS_TIMEOUT_MASK;
515 optype = flags & CIFS_OP_MASK;
517 if ((flags & CIFS_HAS_CREDITS) == 0) {
518 rc = wait_for_free_request(server, timeout, optype);
524 mutex_lock(&server->srv_mutex);
525 mid = server->ops->setup_async_request(server, rqst);
527 mutex_unlock(&server->srv_mutex);
528 add_credits_and_wake_if(server, credits, optype);
532 mid->receive = receive;
533 mid->callback = callback;
534 mid->callback_data = cbdata;
535 mid->handle = handle;
536 mid->mid_state = MID_REQUEST_SUBMITTED;
538 /* put it on the pending_mid_q */
539 spin_lock(&GlobalMid_Lock);
540 list_add_tail(&mid->qhead, &server->pending_mid_q);
541 spin_unlock(&GlobalMid_Lock);
544 cifs_in_send_inc(server);
545 rc = smb_send_rqst(server, rqst, flags);
546 cifs_in_send_dec(server);
547 cifs_save_when_sent(mid);
550 server->sequence_number -= 2;
551 cifs_delete_mid(mid);
554 mutex_unlock(&server->srv_mutex);
559 add_credits_and_wake_if(server, credits, optype);
565 * Send an SMB Request. No response info (other than return code)
566 * needs to be parsed.
568 * flags indicate the type of request buffer and how long to wait
569 * and whether to log NT STATUS code (error) before mapping it to POSIX error
573 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
574 char *in_buf, int flags)
581 iov[0].iov_base = in_buf;
582 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
583 flags |= CIFS_NO_RESP;
584 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
585 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
591 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
595 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
596 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
598 spin_lock(&GlobalMid_Lock);
599 switch (mid->mid_state) {
600 case MID_RESPONSE_RECEIVED:
601 spin_unlock(&GlobalMid_Lock);
603 case MID_RETRY_NEEDED:
606 case MID_RESPONSE_MALFORMED:
613 list_del_init(&mid->qhead);
614 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
615 __func__, mid->mid, mid->mid_state);
618 spin_unlock(&GlobalMid_Lock);
620 mutex_lock(&server->srv_mutex);
621 DeleteMidQEntry(mid);
622 mutex_unlock(&server->srv_mutex);
627 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
628 struct mid_q_entry *mid)
630 return server->ops->send_cancel ?
631 server->ops->send_cancel(server, rqst, mid) : 0;
635 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
638 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
640 dump_smb(mid->resp_buf, min_t(u32, 92, len));
642 /* convert the length into a more usable form */
646 struct smb_rqst rqst = { .rq_iov = iov,
649 iov[0].iov_base = mid->resp_buf;
651 iov[1].iov_base = (char *)mid->resp_buf + 4;
652 iov[1].iov_len = len - 4;
653 /* FIXME: add code to kill session */
654 rc = cifs_verify_signature(&rqst, server,
655 mid->sequence_number);
657 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
661 /* BB special case reconnect tid and uid here? */
662 return map_smb_to_linux_error(mid->resp_buf, log_error);
666 cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
669 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
670 struct mid_q_entry *mid;
672 if (rqst->rq_iov[0].iov_len != 4 ||
673 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
674 return ERR_PTR(-EIO);
676 rc = allocate_mid(ses, hdr, &mid);
679 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
681 cifs_delete_mid(mid);
688 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
689 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
690 struct kvec *resp_iov)
694 struct mid_q_entry *midQ;
695 unsigned int credits = 1;
698 timeout = flags & CIFS_TIMEOUT_MASK;
699 optype = flags & CIFS_OP_MASK;
701 *resp_buf_type = CIFS_NO_BUFFER; /* no response buf yet */
703 if ((ses == NULL) || (ses->server == NULL)) {
704 cifs_dbg(VFS, "Null session\n");
708 if (ses->server->tcpStatus == CifsExiting)
712 * Ensure that we do not send more than 50 overlapping requests
713 * to the same server. We may make this configurable later or
717 rc = wait_for_free_request(ses->server, timeout, optype);
722 * Make sure that we sign in the same order that we send on this socket
723 * and avoid races inside tcp sendmsg code that could cause corruption
727 mutex_lock(&ses->server->srv_mutex);
729 midQ = ses->server->ops->setup_request(ses, rqst);
731 mutex_unlock(&ses->server->srv_mutex);
732 /* Update # of requests on wire to server */
733 add_credits(ses->server, 1, optype);
734 return PTR_ERR(midQ);
737 midQ->mid_state = MID_REQUEST_SUBMITTED;
738 cifs_in_send_inc(ses->server);
739 rc = smb_send_rqst(ses->server, rqst, flags);
740 cifs_in_send_dec(ses->server);
741 cifs_save_when_sent(midQ);
744 ses->server->sequence_number -= 2;
745 mutex_unlock(&ses->server->srv_mutex);
750 if (timeout == CIFS_ASYNC_OP)
753 rc = wait_for_response(ses->server, midQ);
755 send_cancel(ses->server, rqst, midQ);
756 spin_lock(&GlobalMid_Lock);
757 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
758 midQ->callback = DeleteMidQEntry;
759 spin_unlock(&GlobalMid_Lock);
760 add_credits(ses->server, 1, optype);
763 spin_unlock(&GlobalMid_Lock);
766 rc = cifs_sync_mid_result(midQ, ses->server);
768 add_credits(ses->server, 1, optype);
772 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
774 cifs_dbg(FYI, "Bad MID state?\n");
778 buf = (char *)midQ->resp_buf;
779 resp_iov->iov_base = buf;
780 resp_iov->iov_len = get_rfc1002_length(buf) + 4;
782 *resp_buf_type = CIFS_LARGE_BUFFER;
784 *resp_buf_type = CIFS_SMALL_BUFFER;
786 credits = ses->server->ops->get_credits(midQ);
788 rc = ses->server->ops->check_receive(midQ, ses->server,
789 flags & CIFS_LOG_ERROR);
791 /* mark it so buf will not be freed by cifs_delete_mid */
792 if ((flags & CIFS_NO_RESP) == 0)
793 midQ->resp_buf = NULL;
795 cifs_delete_mid(midQ);
796 add_credits(ses->server, credits, optype);
802 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
803 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
804 const int flags, struct kvec *resp_iov)
806 struct smb_rqst rqst;
807 struct kvec *new_iov;
810 new_iov = kmalloc(sizeof(struct kvec) * (n_vec + 1), GFP_KERNEL);
814 /* 1st iov is a RFC1001 length followed by the rest of the packet */
815 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
817 new_iov[0].iov_base = new_iov[1].iov_base;
818 new_iov[0].iov_len = 4;
819 new_iov[1].iov_base += 4;
820 new_iov[1].iov_len -= 4;
822 memset(&rqst, 0, sizeof(struct smb_rqst));
823 rqst.rq_iov = new_iov;
824 rqst.rq_nvec = n_vec + 1;
826 rc = cifs_send_recv(xid, ses, &rqst, resp_buf_type, flags, resp_iov);
832 SendReceive(const unsigned int xid, struct cifs_ses *ses,
833 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
834 int *pbytes_returned, const int timeout)
837 struct mid_q_entry *midQ;
838 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
839 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
840 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
843 cifs_dbg(VFS, "Null smb session\n");
846 if (ses->server == NULL) {
847 cifs_dbg(VFS, "Null tcp session\n");
851 if (ses->server->tcpStatus == CifsExiting)
854 /* Ensure that we do not send more than 50 overlapping requests
855 to the same server. We may make this configurable later or
858 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
859 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
864 rc = wait_for_free_request(ses->server, timeout, 0);
868 /* make sure that we sign in the same order that we send on this socket
869 and avoid races inside tcp sendmsg code that could cause corruption
872 mutex_lock(&ses->server->srv_mutex);
874 rc = allocate_mid(ses, in_buf, &midQ);
876 mutex_unlock(&ses->server->srv_mutex);
877 /* Update # of requests on wire to server */
878 add_credits(ses->server, 1, 0);
882 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
884 mutex_unlock(&ses->server->srv_mutex);
888 midQ->mid_state = MID_REQUEST_SUBMITTED;
890 cifs_in_send_inc(ses->server);
891 rc = smb_send(ses->server, in_buf, len);
892 cifs_in_send_dec(ses->server);
893 cifs_save_when_sent(midQ);
896 ses->server->sequence_number -= 2;
898 mutex_unlock(&ses->server->srv_mutex);
903 if (timeout == CIFS_ASYNC_OP)
906 rc = wait_for_response(ses->server, midQ);
908 send_cancel(ses->server, &rqst, midQ);
909 spin_lock(&GlobalMid_Lock);
910 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
911 /* no longer considered to be "in-flight" */
912 midQ->callback = DeleteMidQEntry;
913 spin_unlock(&GlobalMid_Lock);
914 add_credits(ses->server, 1, 0);
917 spin_unlock(&GlobalMid_Lock);
920 rc = cifs_sync_mid_result(midQ, ses->server);
922 add_credits(ses->server, 1, 0);
926 if (!midQ->resp_buf || !out_buf ||
927 midQ->mid_state != MID_RESPONSE_RECEIVED) {
929 cifs_dbg(VFS, "Bad MID state?\n");
933 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
934 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
935 rc = cifs_check_receive(midQ, ses->server, 0);
937 cifs_delete_mid(midQ);
938 add_credits(ses->server, 1, 0);
943 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
944 blocking lock to return. */
947 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
948 struct smb_hdr *in_buf,
949 struct smb_hdr *out_buf)
952 struct cifs_ses *ses = tcon->ses;
953 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
955 /* We just modify the current in_buf to change
956 the type of lock from LOCKING_ANDX_SHARED_LOCK
957 or LOCKING_ANDX_EXCLUSIVE_LOCK to
958 LOCKING_ANDX_CANCEL_LOCK. */
960 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
962 pSMB->hdr.Mid = get_next_mid(ses->server);
964 return SendReceive(xid, ses, in_buf, out_buf,
969 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
970 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
971 int *pbytes_returned)
975 struct mid_q_entry *midQ;
976 struct cifs_ses *ses;
977 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
978 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
979 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
981 if (tcon == NULL || tcon->ses == NULL) {
982 cifs_dbg(VFS, "Null smb session\n");
987 if (ses->server == NULL) {
988 cifs_dbg(VFS, "Null tcp session\n");
992 if (ses->server->tcpStatus == CifsExiting)
995 /* Ensure that we do not send more than 50 overlapping requests
996 to the same server. We may make this configurable later or
999 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1000 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1005 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
1009 /* make sure that we sign in the same order that we send on this socket
1010 and avoid races inside tcp sendmsg code that could cause corruption
1013 mutex_lock(&ses->server->srv_mutex);
1015 rc = allocate_mid(ses, in_buf, &midQ);
1017 mutex_unlock(&ses->server->srv_mutex);
1021 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1023 cifs_delete_mid(midQ);
1024 mutex_unlock(&ses->server->srv_mutex);
1028 midQ->mid_state = MID_REQUEST_SUBMITTED;
1029 cifs_in_send_inc(ses->server);
1030 rc = smb_send(ses->server, in_buf, len);
1031 cifs_in_send_dec(ses->server);
1032 cifs_save_when_sent(midQ);
1035 ses->server->sequence_number -= 2;
1037 mutex_unlock(&ses->server->srv_mutex);
1040 cifs_delete_mid(midQ);
1044 /* Wait for a reply - allow signals to interrupt. */
1045 rc = wait_event_interruptible(ses->server->response_q,
1046 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1047 ((ses->server->tcpStatus != CifsGood) &&
1048 (ses->server->tcpStatus != CifsNew)));
1050 /* Were we interrupted by a signal ? */
1051 if ((rc == -ERESTARTSYS) &&
1052 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1053 ((ses->server->tcpStatus == CifsGood) ||
1054 (ses->server->tcpStatus == CifsNew))) {
1056 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1057 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1058 blocking lock to return. */
1059 rc = send_cancel(ses->server, &rqst, midQ);
1061 cifs_delete_mid(midQ);
1065 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1066 to cause the blocking lock to return. */
1068 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1070 /* If we get -ENOLCK back the lock may have
1071 already been removed. Don't exit in this case. */
1072 if (rc && rc != -ENOLCK) {
1073 cifs_delete_mid(midQ);
1078 rc = wait_for_response(ses->server, midQ);
1080 send_cancel(ses->server, &rqst, midQ);
1081 spin_lock(&GlobalMid_Lock);
1082 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1083 /* no longer considered to be "in-flight" */
1084 midQ->callback = DeleteMidQEntry;
1085 spin_unlock(&GlobalMid_Lock);
1088 spin_unlock(&GlobalMid_Lock);
1091 /* We got the response - restart system call. */
1095 rc = cifs_sync_mid_result(midQ, ses->server);
1099 /* rcvd frame is ok */
1100 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1102 cifs_dbg(VFS, "Bad MID state?\n");
1106 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1107 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1108 rc = cifs_check_receive(midQ, ses->server, 0);
1110 cifs_delete_mid(midQ);
1111 if (rstart && rc == -EACCES)
1112 return -ERESTARTSYS;