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 = smb_buffer->Mid; /* always LE */
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 printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %llu",
103 midEntry->command, midEntry->mid);
104 printk(" 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 * @iov: Pointer to array of kvecs
128 * @n_vec: length of kvec array
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 kvec *iov, size_t n_vec,
140 struct msghdr smb_msg;
141 unsigned int remaining;
142 size_t first_vec = 0;
143 struct socket *ssocket = server->ssocket;
147 smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
148 smb_msg.msg_namelen = sizeof(struct sockaddr);
149 smb_msg.msg_control = NULL;
150 smb_msg.msg_controllen = 0;
151 if (server->noblocksnd)
152 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
154 smb_msg.msg_flags = MSG_NOSIGNAL;
157 for (i = 0; i < n_vec; i++)
158 remaining += iov[i].iov_len;
163 * If blocking send, we try 3 times, since each can block
164 * for 5 seconds. For nonblocking we have to try more
165 * but wait increasing amounts of time allowing time for
166 * socket to clear. The overall time we wait in either
167 * case to send on the socket is about 15 seconds.
168 * Similarly we wait for 15 seconds for a response from
169 * the server in SendReceive[2] for the server to send
170 * a response back for most types of requests (except
171 * SMB Write past end of file which can be slow, and
172 * blocking lock operations). NFS waits slightly longer
173 * than CIFS, but this can make it take longer for
174 * nonresponsive servers to be detected and 15 seconds
175 * is more than enough time for modern networks to
176 * send a packet. In most cases if we fail to send
177 * after the retries we will kill the socket and
178 * reconnect which may clear the network problem.
180 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
181 n_vec - first_vec, remaining);
184 if (i >= 14 || (!server->noblocksnd && (i > 2))) {
185 cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
197 /* send was at least partially successful */
200 if (rc == remaining) {
205 if (rc > remaining) {
206 cifs_dbg(VFS, "sent %d requested %d\n", rc, remaining);
211 /* should never happen, letting socket clear before
212 retrying is our only obvious option here */
213 cifs_dbg(VFS, "tcp sent no data\n");
220 /* the line below resets i */
221 for (i = first_vec; i < n_vec; i++) {
222 if (iov[i].iov_len) {
223 if (rc > iov[i].iov_len) {
224 rc -= iov[i].iov_len;
227 iov[i].iov_base += rc;
228 iov[i].iov_len -= rc;
235 i = 0; /* in case we get ENOSPC on the next send */
242 * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec
243 * @rqst: pointer to smb_rqst
244 * @idx: index into the array of the page
245 * @iov: pointer to struct kvec that will hold the result
247 * Helper function to convert a slot in the rqst->rq_pages array into a kvec.
248 * The page will be kmapped and the address placed into iov_base. The length
249 * will then be adjusted according to the ptailoff.
252 cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
256 * FIXME: We could avoid this kmap altogether if we used
257 * kernel_sendpage instead of kernel_sendmsg. That will only
258 * work if signing is disabled though as sendpage inlines the
259 * page directly into the fraglist. If userspace modifies the
260 * page after we calculate the signature, then the server will
261 * reject it and may break the connection. kernel_sendmsg does
262 * an extra copy of the data and avoids that issue.
264 iov->iov_base = kmap(rqst->rq_pages[idx]);
266 /* if last page, don't send beyond this offset into page */
267 if (idx == (rqst->rq_npages - 1))
268 iov->iov_len = rqst->rq_tailsz;
270 iov->iov_len = rqst->rq_pagesz;
274 smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
277 struct kvec *iov = rqst->rq_iov;
278 int n_vec = rqst->rq_nvec;
279 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
281 size_t total_len = 0, sent;
282 struct socket *ssocket = server->ssocket;
288 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
289 dump_smb(iov[0].iov_base, iov[0].iov_len);
291 /* cork the socket */
292 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
293 (char *)&val, sizeof(val));
295 rc = smb_send_kvec(server, iov, n_vec, &sent);
301 /* now walk the page array and send each page in it */
302 for (i = 0; i < rqst->rq_npages; i++) {
305 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
306 rc = smb_send_kvec(server, &p_iov, 1, &sent);
307 kunmap(rqst->rq_pages[i]);
317 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
318 (char *)&val, sizeof(val));
320 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
321 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
322 smb_buf_length + 4, total_len);
324 * If we have only sent part of an SMB then the next SMB could
325 * be taken as the remainder of this one. We need to kill the
326 * socket so the server throws away the partial SMB
328 server->tcpStatus = CifsNeedReconnect;
331 if (rc < 0 && rc != -EINTR)
332 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
341 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
343 struct smb_rqst rqst = { .rq_iov = iov,
346 return smb_send_rqst(server, &rqst);
350 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
351 unsigned int smb_buf_length)
355 iov.iov_base = smb_buffer;
356 iov.iov_len = smb_buf_length + 4;
358 return smb_sendv(server, &iov, 1);
362 wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
367 spin_lock(&server->req_lock);
368 if (timeout == CIFS_ASYNC_OP) {
369 /* oplock breaks must not be held up */
372 spin_unlock(&server->req_lock);
378 spin_unlock(&server->req_lock);
379 cifs_num_waiters_inc(server);
380 rc = wait_event_killable(server->request_q,
381 has_credits(server, credits));
382 cifs_num_waiters_dec(server);
385 spin_lock(&server->req_lock);
387 if (server->tcpStatus == CifsExiting) {
388 spin_unlock(&server->req_lock);
393 * Can not count locking commands against total
394 * as they are allowed to block on server.
397 /* update # of requests on the wire to server */
398 if (timeout != CIFS_BLOCKING_OP) {
402 spin_unlock(&server->req_lock);
410 wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
413 return wait_for_free_credits(server, timeout,
414 server->ops->get_credits_field(server, optype));
417 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
418 struct mid_q_entry **ppmidQ)
420 if (ses->server->tcpStatus == CifsExiting) {
424 if (ses->server->tcpStatus == CifsNeedReconnect) {
425 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
429 if (ses->status != CifsGood) {
430 /* check if SMB session is bad because we are setting it up */
431 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
432 (in_buf->Command != SMB_COM_NEGOTIATE))
434 /* else ok - we are setting up session */
436 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
439 spin_lock(&GlobalMid_Lock);
440 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
441 spin_unlock(&GlobalMid_Lock);
446 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
450 error = wait_event_freezekillable(server->response_q,
451 midQ->mid_state != MID_REQUEST_SUBMITTED);
459 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
462 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
463 struct mid_q_entry *mid;
465 /* enable signing if server requires it */
466 if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
467 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
469 mid = AllocMidQEntry(hdr, server);
471 return ERR_PTR(-ENOMEM);
473 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
475 DeleteMidQEntry(mid);
483 * Send a SMB request and set the callback function in the mid to handle
484 * the result. Caller is responsible for dealing with timeouts.
487 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
488 mid_receive_t *receive, mid_callback_t *callback,
489 void *cbdata, const int flags)
491 int rc, timeout, optype;
492 struct mid_q_entry *mid;
494 timeout = flags & CIFS_TIMEOUT_MASK;
495 optype = flags & CIFS_OP_MASK;
497 rc = wait_for_free_request(server, timeout, optype);
501 mutex_lock(&server->srv_mutex);
502 mid = server->ops->setup_async_request(server, rqst);
504 mutex_unlock(&server->srv_mutex);
505 add_credits(server, 1, optype);
506 wake_up(&server->request_q);
510 mid->receive = receive;
511 mid->callback = callback;
512 mid->callback_data = cbdata;
513 mid->mid_state = MID_REQUEST_SUBMITTED;
515 /* put it on the pending_mid_q */
516 spin_lock(&GlobalMid_Lock);
517 list_add_tail(&mid->qhead, &server->pending_mid_q);
518 spin_unlock(&GlobalMid_Lock);
521 cifs_in_send_inc(server);
522 rc = smb_send_rqst(server, rqst);
523 cifs_in_send_dec(server);
524 cifs_save_when_sent(mid);
525 mutex_unlock(&server->srv_mutex);
530 cifs_delete_mid(mid);
531 add_credits(server, 1, optype);
532 wake_up(&server->request_q);
538 * Send an SMB Request. No response info (other than return code)
539 * needs to be parsed.
541 * flags indicate the type of request buffer and how long to wait
542 * and whether to log NT STATUS code (error) before mapping it to POSIX error
546 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
547 char *in_buf, int flags)
553 iov[0].iov_base = in_buf;
554 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
555 flags |= CIFS_NO_RESP;
556 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
557 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
563 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
567 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
568 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
570 spin_lock(&GlobalMid_Lock);
571 switch (mid->mid_state) {
572 case MID_RESPONSE_RECEIVED:
573 spin_unlock(&GlobalMid_Lock);
575 case MID_RETRY_NEEDED:
578 case MID_RESPONSE_MALFORMED:
585 list_del_init(&mid->qhead);
586 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
587 __func__, mid->mid, mid->mid_state);
590 spin_unlock(&GlobalMid_Lock);
592 DeleteMidQEntry(mid);
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 */
612 if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
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 + 1);
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);
714 mutex_unlock(&ses->server->srv_mutex);
717 cifs_small_buf_release(buf);
721 if (timeout == CIFS_ASYNC_OP) {
722 cifs_small_buf_release(buf);
726 rc = wait_for_response(ses->server, midQ);
728 send_cancel(ses->server, buf, midQ);
729 spin_lock(&GlobalMid_Lock);
730 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
731 midQ->callback = DeleteMidQEntry;
732 spin_unlock(&GlobalMid_Lock);
733 cifs_small_buf_release(buf);
734 add_credits(ses->server, 1, optype);
737 spin_unlock(&GlobalMid_Lock);
740 cifs_small_buf_release(buf);
742 rc = cifs_sync_mid_result(midQ, ses->server);
744 add_credits(ses->server, 1, optype);
748 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
750 cifs_dbg(FYI, "Bad MID state?\n");
754 buf = (char *)midQ->resp_buf;
755 iov[0].iov_base = buf;
756 iov[0].iov_len = get_rfc1002_length(buf) + 4;
758 *resp_buf_type = CIFS_LARGE_BUFFER;
760 *resp_buf_type = CIFS_SMALL_BUFFER;
762 credits = ses->server->ops->get_credits(midQ);
764 rc = ses->server->ops->check_receive(midQ, ses->server,
765 flags & CIFS_LOG_ERROR);
767 /* mark it so buf will not be freed by cifs_delete_mid */
768 if ((flags & CIFS_NO_RESP) == 0)
769 midQ->resp_buf = NULL;
771 cifs_delete_mid(midQ);
772 add_credits(ses->server, credits, optype);
778 SendReceive(const unsigned int xid, struct cifs_ses *ses,
779 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
780 int *pbytes_returned, const int timeout)
783 struct mid_q_entry *midQ;
786 cifs_dbg(VFS, "Null smb session\n");
789 if (ses->server == NULL) {
790 cifs_dbg(VFS, "Null tcp session\n");
794 if (ses->server->tcpStatus == CifsExiting)
797 /* Ensure that we do not send more than 50 overlapping requests
798 to the same server. We may make this configurable later or
801 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
802 MAX_CIFS_HDR_SIZE - 4) {
803 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
804 be32_to_cpu(in_buf->smb_buf_length));
808 rc = wait_for_free_request(ses->server, timeout, 0);
812 /* make sure that we sign in the same order that we send on this socket
813 and avoid races inside tcp sendmsg code that could cause corruption
816 mutex_lock(&ses->server->srv_mutex);
818 rc = allocate_mid(ses, in_buf, &midQ);
820 mutex_unlock(&ses->server->srv_mutex);
821 /* Update # of requests on wire to server */
822 add_credits(ses->server, 1, 0);
826 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
828 mutex_unlock(&ses->server->srv_mutex);
832 midQ->mid_state = MID_REQUEST_SUBMITTED;
834 cifs_in_send_inc(ses->server);
835 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
836 cifs_in_send_dec(ses->server);
837 cifs_save_when_sent(midQ);
838 mutex_unlock(&ses->server->srv_mutex);
843 if (timeout == CIFS_ASYNC_OP)
846 rc = wait_for_response(ses->server, midQ);
848 send_cancel(ses->server, in_buf, midQ);
849 spin_lock(&GlobalMid_Lock);
850 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
851 /* no longer considered to be "in-flight" */
852 midQ->callback = DeleteMidQEntry;
853 spin_unlock(&GlobalMid_Lock);
854 add_credits(ses->server, 1, 0);
857 spin_unlock(&GlobalMid_Lock);
860 rc = cifs_sync_mid_result(midQ, ses->server);
862 add_credits(ses->server, 1, 0);
866 if (!midQ->resp_buf || !out_buf ||
867 midQ->mid_state != MID_RESPONSE_RECEIVED) {
869 cifs_dbg(VFS, "Bad MID state?\n");
873 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
874 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
875 rc = cifs_check_receive(midQ, ses->server, 0);
877 cifs_delete_mid(midQ);
878 add_credits(ses->server, 1, 0);
883 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
884 blocking lock to return. */
887 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
888 struct smb_hdr *in_buf,
889 struct smb_hdr *out_buf)
892 struct cifs_ses *ses = tcon->ses;
893 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
895 /* We just modify the current in_buf to change
896 the type of lock from LOCKING_ANDX_SHARED_LOCK
897 or LOCKING_ANDX_EXCLUSIVE_LOCK to
898 LOCKING_ANDX_CANCEL_LOCK. */
900 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
902 pSMB->hdr.Mid = get_next_mid(ses->server);
904 return SendReceive(xid, ses, in_buf, out_buf,
909 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
910 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
911 int *pbytes_returned)
915 struct mid_q_entry *midQ;
916 struct cifs_ses *ses;
918 if (tcon == NULL || tcon->ses == NULL) {
919 cifs_dbg(VFS, "Null smb session\n");
924 if (ses->server == NULL) {
925 cifs_dbg(VFS, "Null tcp session\n");
929 if (ses->server->tcpStatus == CifsExiting)
932 /* Ensure that we do not send more than 50 overlapping requests
933 to the same server. We may make this configurable later or
936 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
937 MAX_CIFS_HDR_SIZE - 4) {
938 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
939 be32_to_cpu(in_buf->smb_buf_length));
943 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
947 /* make sure that we sign in the same order that we send on this socket
948 and avoid races inside tcp sendmsg code that could cause corruption
951 mutex_lock(&ses->server->srv_mutex);
953 rc = allocate_mid(ses, in_buf, &midQ);
955 mutex_unlock(&ses->server->srv_mutex);
959 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
961 cifs_delete_mid(midQ);
962 mutex_unlock(&ses->server->srv_mutex);
966 midQ->mid_state = MID_REQUEST_SUBMITTED;
967 cifs_in_send_inc(ses->server);
968 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
969 cifs_in_send_dec(ses->server);
970 cifs_save_when_sent(midQ);
971 mutex_unlock(&ses->server->srv_mutex);
974 cifs_delete_mid(midQ);
978 /* Wait for a reply - allow signals to interrupt. */
979 rc = wait_event_interruptible(ses->server->response_q,
980 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
981 ((ses->server->tcpStatus != CifsGood) &&
982 (ses->server->tcpStatus != CifsNew)));
984 /* Were we interrupted by a signal ? */
985 if ((rc == -ERESTARTSYS) &&
986 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
987 ((ses->server->tcpStatus == CifsGood) ||
988 (ses->server->tcpStatus == CifsNew))) {
990 if (in_buf->Command == SMB_COM_TRANSACTION2) {
991 /* POSIX lock. We send a NT_CANCEL SMB to cause the
992 blocking lock to return. */
993 rc = send_cancel(ses->server, in_buf, midQ);
995 cifs_delete_mid(midQ);
999 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1000 to cause the blocking lock to return. */
1002 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1004 /* If we get -ENOLCK back the lock may have
1005 already been removed. Don't exit in this case. */
1006 if (rc && rc != -ENOLCK) {
1007 cifs_delete_mid(midQ);
1012 rc = wait_for_response(ses->server, midQ);
1014 send_cancel(ses->server, in_buf, midQ);
1015 spin_lock(&GlobalMid_Lock);
1016 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1017 /* no longer considered to be "in-flight" */
1018 midQ->callback = DeleteMidQEntry;
1019 spin_unlock(&GlobalMid_Lock);
1022 spin_unlock(&GlobalMid_Lock);
1025 /* We got the response - restart system call. */
1029 rc = cifs_sync_mid_result(midQ, ses->server);
1033 /* rcvd frame is ok */
1034 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1036 cifs_dbg(VFS, "Bad MID state?\n");
1040 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1041 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1042 rc = cifs_check_receive(midQ, ses->server, 0);
1044 cifs_delete_mid(midQ);
1045 if (rstart && rc == -EACCES)
1046 return -ERESTARTSYS;