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/highmem.h>
32 #include <asm/uaccess.h>
33 #include <asm/processor.h>
34 #include <linux/mempool.h>
37 #include "cifsproto.h"
38 #include "cifs_debug.h"
41 cifs_wake_up_task(struct mid_q_entry *mid)
43 wake_up_process(mid->callback_data);
47 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
49 struct mid_q_entry *temp;
52 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
56 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
60 memset(temp, 0, sizeof(struct mid_q_entry));
61 temp->mid = get_mid(smb_buffer);
62 temp->pid = current->pid;
63 temp->command = cpu_to_le16(smb_buffer->Command);
64 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
65 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
66 /* when mid allocated can be before when sent */
67 temp->when_alloc = jiffies;
68 temp->server = server;
71 * The default is for the mid to be synchronous, so the
72 * default callback just wakes up the current task.
74 temp->callback = cifs_wake_up_task;
75 temp->callback_data = current;
78 atomic_inc(&midCount);
79 temp->mid_state = MID_REQUEST_ALLOCATED;
84 DeleteMidQEntry(struct mid_q_entry *midEntry)
86 #ifdef CONFIG_CIFS_STATS2
87 __le16 command = midEntry->server->vals->lock_cmd;
90 midEntry->mid_state = MID_FREE;
91 atomic_dec(&midCount);
92 if (midEntry->large_buf)
93 cifs_buf_release(midEntry->resp_buf);
95 cifs_small_buf_release(midEntry->resp_buf);
96 #ifdef CONFIG_CIFS_STATS2
98 /* commands taking longer than one second are indications that
99 something is wrong, unless it is quite a slow link or server */
100 if ((now - midEntry->when_alloc) > HZ) {
101 if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) {
102 pr_debug(" CIFS slow rsp: cmd %d mid %llu",
103 midEntry->command, midEntry->mid);
104 pr_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
105 now - midEntry->when_alloc,
106 now - midEntry->when_sent,
107 now - midEntry->when_received);
111 mempool_free(midEntry, cifs_mid_poolp);
115 cifs_delete_mid(struct mid_q_entry *mid)
117 spin_lock(&GlobalMid_Lock);
118 list_del(&mid->qhead);
119 spin_unlock(&GlobalMid_Lock);
121 DeleteMidQEntry(mid);
125 * smb_send_kvec - send an array of kvecs to the server
126 * @server: Server to send the data to
127 * @smb_msg: Message to send
128 * @sent: amount of data sent on socket is stored here
130 * Our basic "send data to server" function. Should be called with srv_mutex
131 * held. The caller is responsible for handling the results.
134 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
139 struct socket *ssocket = server->ssocket;
143 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
144 smb_msg->msg_namelen = sizeof(struct sockaddr);
145 smb_msg->msg_control = NULL;
146 smb_msg->msg_controllen = 0;
147 if (server->noblocksnd)
148 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
150 smb_msg->msg_flags = MSG_NOSIGNAL;
152 while (msg_data_left(smb_msg)) {
154 * If blocking send, we try 3 times, since each can block
155 * for 5 seconds. For nonblocking we have to try more
156 * but wait increasing amounts of time allowing time for
157 * socket to clear. The overall time we wait in either
158 * case to send on the socket is about 15 seconds.
159 * Similarly we wait for 15 seconds for a response from
160 * the server in SendReceive[2] for the server to send
161 * a response back for most types of requests (except
162 * SMB Write past end of file which can be slow, and
163 * blocking lock operations). NFS waits slightly longer
164 * than CIFS, but this can make it take longer for
165 * nonresponsive servers to be detected and 15 seconds
166 * is more than enough time for modern networks to
167 * send a packet. In most cases if we fail to send
168 * after the retries we will kill the socket and
169 * reconnect which may clear the network problem.
171 rc = sock_sendmsg(ssocket, smb_msg);
175 (!server->noblocksnd && (retries > 2))) {
176 cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
180 msleep(1 << retries);
188 /* should never happen, letting socket clear before
189 retrying is our only obvious option here */
190 cifs_dbg(VFS, "tcp sent no data\n");
195 /* send was at least partially successful */
197 retries = 0; /* in case we get ENOSPC on the next send */
203 rqst_len(struct smb_rqst *rqst)
206 struct kvec *iov = rqst->rq_iov;
207 unsigned long buflen = 0;
209 /* total up iov array first */
210 for (i = 0; i < rqst->rq_nvec; i++)
211 buflen += iov[i].iov_len;
213 /* add in the page array if there is one */
214 if (rqst->rq_npages) {
215 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
216 buflen += rqst->rq_tailsz;
223 smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
226 struct kvec *iov = rqst->rq_iov;
227 int n_vec = rqst->rq_nvec;
228 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
229 unsigned long send_length;
231 size_t total_len = 0, sent, size;
232 struct socket *ssocket = server->ssocket;
233 struct msghdr smb_msg;
239 /* sanity check send length */
240 send_length = rqst_len(rqst);
241 if (send_length != smb_buf_length + 4) {
242 WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
243 send_length, smb_buf_length);
247 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
248 dump_smb(iov[0].iov_base, iov[0].iov_len);
250 /* cork the socket */
251 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
252 (char *)&val, sizeof(val));
255 for (i = 0; i < n_vec; i++)
256 size += iov[i].iov_len;
258 iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, iov, n_vec, size);
260 rc = smb_send_kvec(server, &smb_msg, &sent);
266 /* now walk the page array and send each page in it */
267 for (i = 0; i < rqst->rq_npages; i++) {
268 size_t len = i == rqst->rq_npages - 1
271 struct bio_vec bvec = {
272 .bv_page = rqst->rq_pages[i],
275 iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
277 rc = smb_send_kvec(server, &smb_msg, &sent);
287 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
288 (char *)&val, sizeof(val));
290 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
291 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
292 smb_buf_length + 4, total_len);
294 * If we have only sent part of an SMB then the next SMB could
295 * be taken as the remainder of this one. We need to kill the
296 * socket so the server throws away the partial SMB
298 server->tcpStatus = CifsNeedReconnect;
301 if (rc < 0 && rc != -EINTR)
302 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
311 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
313 struct smb_rqst rqst = { .rq_iov = iov,
316 return smb_send_rqst(server, &rqst);
320 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
321 unsigned int smb_buf_length)
325 iov.iov_base = smb_buffer;
326 iov.iov_len = smb_buf_length + 4;
328 return smb_sendv(server, &iov, 1);
332 wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
337 spin_lock(&server->req_lock);
338 if (timeout == CIFS_ASYNC_OP) {
339 /* oplock breaks must not be held up */
342 spin_unlock(&server->req_lock);
348 spin_unlock(&server->req_lock);
349 cifs_num_waiters_inc(server);
350 rc = wait_event_killable(server->request_q,
351 has_credits(server, credits));
352 cifs_num_waiters_dec(server);
355 spin_lock(&server->req_lock);
357 if (server->tcpStatus == CifsExiting) {
358 spin_unlock(&server->req_lock);
363 * Can not count locking commands against total
364 * as they are allowed to block on server.
367 /* update # of requests on the wire to server */
368 if (timeout != CIFS_BLOCKING_OP) {
372 spin_unlock(&server->req_lock);
380 wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
385 val = server->ops->get_credits_field(server, optype);
386 /* Since an echo is already inflight, no need to wait to send another */
387 if (*val <= 0 && optype == CIFS_ECHO_OP)
389 return wait_for_free_credits(server, timeout, val);
393 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
394 unsigned int *num, unsigned int *credits)
401 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
402 struct mid_q_entry **ppmidQ)
404 if (ses->server->tcpStatus == CifsExiting) {
408 if (ses->server->tcpStatus == CifsNeedReconnect) {
409 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
413 if (ses->status == CifsNew) {
414 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
415 (in_buf->Command != SMB_COM_NEGOTIATE))
417 /* else ok - we are setting up session */
420 if (ses->status == CifsExiting) {
421 /* check if SMB session is bad because we are setting it up */
422 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
424 /* else ok - we are shutting down session */
427 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
430 spin_lock(&GlobalMid_Lock);
431 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
432 spin_unlock(&GlobalMid_Lock);
437 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
441 error = wait_event_freezekillable_unsafe(server->response_q,
442 midQ->mid_state != MID_REQUEST_SUBMITTED);
450 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
453 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
454 struct mid_q_entry *mid;
456 /* enable signing if server requires it */
458 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
460 mid = AllocMidQEntry(hdr, server);
462 return ERR_PTR(-ENOMEM);
464 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
466 DeleteMidQEntry(mid);
474 * Send a SMB request and set the callback function in the mid to handle
475 * the result. Caller is responsible for dealing with timeouts.
478 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
479 mid_receive_t *receive, mid_callback_t *callback,
480 void *cbdata, const int flags)
482 int rc, timeout, optype;
483 struct mid_q_entry *mid;
484 unsigned int credits = 0;
486 timeout = flags & CIFS_TIMEOUT_MASK;
487 optype = flags & CIFS_OP_MASK;
489 if ((flags & CIFS_HAS_CREDITS) == 0) {
490 rc = wait_for_free_request(server, timeout, optype);
496 mutex_lock(&server->srv_mutex);
497 mid = server->ops->setup_async_request(server, rqst);
499 mutex_unlock(&server->srv_mutex);
500 add_credits_and_wake_if(server, credits, optype);
504 mid->receive = receive;
505 mid->callback = callback;
506 mid->callback_data = cbdata;
507 mid->mid_state = MID_REQUEST_SUBMITTED;
509 /* put it on the pending_mid_q */
510 spin_lock(&GlobalMid_Lock);
511 list_add_tail(&mid->qhead, &server->pending_mid_q);
512 spin_unlock(&GlobalMid_Lock);
515 cifs_in_send_inc(server);
516 rc = smb_send_rqst(server, rqst);
517 cifs_in_send_dec(server);
518 cifs_save_when_sent(mid);
521 server->sequence_number -= 2;
522 cifs_delete_mid(mid);
525 mutex_unlock(&server->srv_mutex);
530 add_credits_and_wake_if(server, credits, optype);
536 * Send an SMB Request. No response info (other than return code)
537 * needs to be parsed.
539 * flags indicate the type of request buffer and how long to wait
540 * and whether to log NT STATUS code (error) before mapping it to POSIX error
544 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
545 char *in_buf, int flags)
551 iov[0].iov_base = in_buf;
552 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
553 flags |= CIFS_NO_RESP;
554 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
555 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
561 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
565 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
566 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
568 spin_lock(&GlobalMid_Lock);
569 switch (mid->mid_state) {
570 case MID_RESPONSE_RECEIVED:
571 spin_unlock(&GlobalMid_Lock);
573 case MID_RETRY_NEEDED:
576 case MID_RESPONSE_MALFORMED:
583 list_del_init(&mid->qhead);
584 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
585 __func__, mid->mid, mid->mid_state);
588 spin_unlock(&GlobalMid_Lock);
590 mutex_lock(&server->srv_mutex);
591 DeleteMidQEntry(mid);
592 mutex_unlock(&server->srv_mutex);
597 send_cancel(struct TCP_Server_Info *server, void *buf, struct mid_q_entry *mid)
599 return server->ops->send_cancel ?
600 server->ops->send_cancel(server, buf, mid) : 0;
604 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
607 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
609 dump_smb(mid->resp_buf, min_t(u32, 92, len));
611 /* convert the length into a more usable form */
615 struct smb_rqst rqst = { .rq_iov = &iov,
618 iov.iov_base = mid->resp_buf;
620 /* FIXME: add code to kill session */
621 rc = cifs_verify_signature(&rqst, server,
622 mid->sequence_number);
624 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
628 /* BB special case reconnect tid and uid here? */
629 return map_smb_to_linux_error(mid->resp_buf, log_error);
633 cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
636 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
637 struct mid_q_entry *mid;
639 rc = allocate_mid(ses, hdr, &mid);
642 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
644 cifs_delete_mid(mid);
651 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
652 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
657 struct mid_q_entry *midQ;
658 char *buf = iov[0].iov_base;
659 unsigned int credits = 1;
660 struct smb_rqst rqst = { .rq_iov = iov,
663 timeout = flags & CIFS_TIMEOUT_MASK;
664 optype = flags & CIFS_OP_MASK;
666 *resp_buf_type = CIFS_NO_BUFFER; /* no response buf yet */
668 if ((ses == NULL) || (ses->server == NULL)) {
669 cifs_small_buf_release(buf);
670 cifs_dbg(VFS, "Null session\n");
674 if (ses->server->tcpStatus == CifsExiting) {
675 cifs_small_buf_release(buf);
680 * Ensure that we do not send more than 50 overlapping requests
681 * to the same server. We may make this configurable later or
685 rc = wait_for_free_request(ses->server, timeout, optype);
687 cifs_small_buf_release(buf);
692 * Make sure that we sign in the same order that we send on this socket
693 * and avoid races inside tcp sendmsg code that could cause corruption
697 mutex_lock(&ses->server->srv_mutex);
699 midQ = ses->server->ops->setup_request(ses, &rqst);
701 mutex_unlock(&ses->server->srv_mutex);
702 cifs_small_buf_release(buf);
703 /* Update # of requests on wire to server */
704 add_credits(ses->server, 1, optype);
705 return PTR_ERR(midQ);
708 midQ->mid_state = MID_REQUEST_SUBMITTED;
709 cifs_in_send_inc(ses->server);
710 rc = smb_sendv(ses->server, iov, n_vec);
711 cifs_in_send_dec(ses->server);
712 cifs_save_when_sent(midQ);
715 ses->server->sequence_number -= 2;
716 mutex_unlock(&ses->server->srv_mutex);
719 cifs_small_buf_release(buf);
723 if (timeout == CIFS_ASYNC_OP) {
724 cifs_small_buf_release(buf);
728 rc = wait_for_response(ses->server, midQ);
730 send_cancel(ses->server, buf, midQ);
731 spin_lock(&GlobalMid_Lock);
732 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
733 midQ->callback = DeleteMidQEntry;
734 spin_unlock(&GlobalMid_Lock);
735 cifs_small_buf_release(buf);
736 add_credits(ses->server, 1, optype);
739 spin_unlock(&GlobalMid_Lock);
742 cifs_small_buf_release(buf);
744 rc = cifs_sync_mid_result(midQ, ses->server);
746 add_credits(ses->server, 1, optype);
750 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
752 cifs_dbg(FYI, "Bad MID state?\n");
756 buf = (char *)midQ->resp_buf;
757 iov[0].iov_base = buf;
758 iov[0].iov_len = get_rfc1002_length(buf) + 4;
760 *resp_buf_type = CIFS_LARGE_BUFFER;
762 *resp_buf_type = CIFS_SMALL_BUFFER;
764 credits = ses->server->ops->get_credits(midQ);
766 rc = ses->server->ops->check_receive(midQ, ses->server,
767 flags & CIFS_LOG_ERROR);
769 /* mark it so buf will not be freed by cifs_delete_mid */
770 if ((flags & CIFS_NO_RESP) == 0)
771 midQ->resp_buf = NULL;
773 cifs_delete_mid(midQ);
774 add_credits(ses->server, credits, optype);
780 SendReceive(const unsigned int xid, struct cifs_ses *ses,
781 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
782 int *pbytes_returned, const int timeout)
785 struct mid_q_entry *midQ;
788 cifs_dbg(VFS, "Null smb session\n");
791 if (ses->server == NULL) {
792 cifs_dbg(VFS, "Null tcp session\n");
796 if (ses->server->tcpStatus == CifsExiting)
799 /* Ensure that we do not send more than 50 overlapping requests
800 to the same server. We may make this configurable later or
803 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
804 MAX_CIFS_HDR_SIZE - 4) {
805 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
806 be32_to_cpu(in_buf->smb_buf_length));
810 rc = wait_for_free_request(ses->server, timeout, 0);
814 /* make sure that we sign in the same order that we send on this socket
815 and avoid races inside tcp sendmsg code that could cause corruption
818 mutex_lock(&ses->server->srv_mutex);
820 rc = allocate_mid(ses, in_buf, &midQ);
822 mutex_unlock(&ses->server->srv_mutex);
823 /* Update # of requests on wire to server */
824 add_credits(ses->server, 1, 0);
828 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
830 mutex_unlock(&ses->server->srv_mutex);
834 midQ->mid_state = MID_REQUEST_SUBMITTED;
836 cifs_in_send_inc(ses->server);
837 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
838 cifs_in_send_dec(ses->server);
839 cifs_save_when_sent(midQ);
842 ses->server->sequence_number -= 2;
844 mutex_unlock(&ses->server->srv_mutex);
849 if (timeout == CIFS_ASYNC_OP)
852 rc = wait_for_response(ses->server, midQ);
854 send_cancel(ses->server, in_buf, midQ);
855 spin_lock(&GlobalMid_Lock);
856 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
857 /* no longer considered to be "in-flight" */
858 midQ->callback = DeleteMidQEntry;
859 spin_unlock(&GlobalMid_Lock);
860 add_credits(ses->server, 1, 0);
863 spin_unlock(&GlobalMid_Lock);
866 rc = cifs_sync_mid_result(midQ, ses->server);
868 add_credits(ses->server, 1, 0);
872 if (!midQ->resp_buf || !out_buf ||
873 midQ->mid_state != MID_RESPONSE_RECEIVED) {
875 cifs_dbg(VFS, "Bad MID state?\n");
879 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
880 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
881 rc = cifs_check_receive(midQ, ses->server, 0);
883 cifs_delete_mid(midQ);
884 add_credits(ses->server, 1, 0);
889 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
890 blocking lock to return. */
893 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
894 struct smb_hdr *in_buf,
895 struct smb_hdr *out_buf)
898 struct cifs_ses *ses = tcon->ses;
899 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
901 /* We just modify the current in_buf to change
902 the type of lock from LOCKING_ANDX_SHARED_LOCK
903 or LOCKING_ANDX_EXCLUSIVE_LOCK to
904 LOCKING_ANDX_CANCEL_LOCK. */
906 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
908 pSMB->hdr.Mid = get_next_mid(ses->server);
910 return SendReceive(xid, ses, in_buf, out_buf,
915 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
916 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
917 int *pbytes_returned)
921 struct mid_q_entry *midQ;
922 struct cifs_ses *ses;
924 if (tcon == NULL || tcon->ses == NULL) {
925 cifs_dbg(VFS, "Null smb session\n");
930 if (ses->server == NULL) {
931 cifs_dbg(VFS, "Null tcp session\n");
935 if (ses->server->tcpStatus == CifsExiting)
938 /* Ensure that we do not send more than 50 overlapping requests
939 to the same server. We may make this configurable later or
942 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
943 MAX_CIFS_HDR_SIZE - 4) {
944 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
945 be32_to_cpu(in_buf->smb_buf_length));
949 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
953 /* make sure that we sign in the same order that we send on this socket
954 and avoid races inside tcp sendmsg code that could cause corruption
957 mutex_lock(&ses->server->srv_mutex);
959 rc = allocate_mid(ses, in_buf, &midQ);
961 mutex_unlock(&ses->server->srv_mutex);
965 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
967 cifs_delete_mid(midQ);
968 mutex_unlock(&ses->server->srv_mutex);
972 midQ->mid_state = MID_REQUEST_SUBMITTED;
973 cifs_in_send_inc(ses->server);
974 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
975 cifs_in_send_dec(ses->server);
976 cifs_save_when_sent(midQ);
979 ses->server->sequence_number -= 2;
981 mutex_unlock(&ses->server->srv_mutex);
984 cifs_delete_mid(midQ);
988 /* Wait for a reply - allow signals to interrupt. */
989 rc = wait_event_interruptible(ses->server->response_q,
990 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
991 ((ses->server->tcpStatus != CifsGood) &&
992 (ses->server->tcpStatus != CifsNew)));
994 /* Were we interrupted by a signal ? */
995 if ((rc == -ERESTARTSYS) &&
996 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
997 ((ses->server->tcpStatus == CifsGood) ||
998 (ses->server->tcpStatus == CifsNew))) {
1000 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1001 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1002 blocking lock to return. */
1003 rc = send_cancel(ses->server, in_buf, midQ);
1005 cifs_delete_mid(midQ);
1009 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1010 to cause the blocking lock to return. */
1012 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1014 /* If we get -ENOLCK back the lock may have
1015 already been removed. Don't exit in this case. */
1016 if (rc && rc != -ENOLCK) {
1017 cifs_delete_mid(midQ);
1022 rc = wait_for_response(ses->server, midQ);
1024 send_cancel(ses->server, in_buf, midQ);
1025 spin_lock(&GlobalMid_Lock);
1026 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1027 /* no longer considered to be "in-flight" */
1028 midQ->callback = DeleteMidQEntry;
1029 spin_unlock(&GlobalMid_Lock);
1032 spin_unlock(&GlobalMid_Lock);
1035 /* We got the response - restart system call. */
1039 rc = cifs_sync_mid_result(midQ, ses->server);
1043 /* rcvd frame is ok */
1044 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1046 cifs_dbg(VFS, "Bad MID state?\n");
1050 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1051 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1052 rc = cifs_check_receive(midQ, ses->server, 0);
1054 cifs_delete_mid(midQ);
1055 if (rstart && rc == -EACCES)
1056 return -ERESTARTSYS;