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 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 rqst_len(struct smb_rqst *rqst)
277 struct kvec *iov = rqst->rq_iov;
278 unsigned long buflen = 0;
280 /* total up iov array first */
281 for (i = 0; i < rqst->rq_nvec; i++)
282 buflen += iov[i].iov_len;
284 /* add in the page array if there is one */
285 if (rqst->rq_npages) {
286 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
287 buflen += rqst->rq_tailsz;
294 smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
297 struct kvec *iov = rqst->rq_iov;
298 int n_vec = rqst->rq_nvec;
299 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
300 unsigned long send_length;
302 size_t total_len = 0, sent;
303 struct socket *ssocket = server->ssocket;
309 /* sanity check send length */
310 send_length = rqst_len(rqst);
311 if (send_length != smb_buf_length + 4) {
312 WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
313 send_length, smb_buf_length);
317 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
318 dump_smb(iov[0].iov_base, iov[0].iov_len);
320 /* cork the socket */
321 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
322 (char *)&val, sizeof(val));
324 rc = smb_send_kvec(server, iov, n_vec, &sent);
330 /* now walk the page array and send each page in it */
331 for (i = 0; i < rqst->rq_npages; i++) {
334 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
335 rc = smb_send_kvec(server, &p_iov, 1, &sent);
336 kunmap(rqst->rq_pages[i]);
346 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
347 (char *)&val, sizeof(val));
349 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
350 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
351 smb_buf_length + 4, total_len);
353 * If we have only sent part of an SMB then the next SMB could
354 * be taken as the remainder of this one. We need to kill the
355 * socket so the server throws away the partial SMB
357 server->tcpStatus = CifsNeedReconnect;
360 if (rc < 0 && rc != -EINTR)
361 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
370 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
372 struct smb_rqst rqst = { .rq_iov = iov,
375 return smb_send_rqst(server, &rqst);
379 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
380 unsigned int smb_buf_length)
384 iov.iov_base = smb_buffer;
385 iov.iov_len = smb_buf_length + 4;
387 return smb_sendv(server, &iov, 1);
391 wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
396 spin_lock(&server->req_lock);
397 if (timeout == CIFS_ASYNC_OP) {
398 /* oplock breaks must not be held up */
401 spin_unlock(&server->req_lock);
407 spin_unlock(&server->req_lock);
408 cifs_num_waiters_inc(server);
409 rc = wait_event_killable(server->request_q,
410 has_credits(server, credits));
411 cifs_num_waiters_dec(server);
414 spin_lock(&server->req_lock);
416 if (server->tcpStatus == CifsExiting) {
417 spin_unlock(&server->req_lock);
422 * Can not count locking commands against total
423 * as they are allowed to block on server.
426 /* update # of requests on the wire to server */
427 if (timeout != CIFS_BLOCKING_OP) {
431 spin_unlock(&server->req_lock);
439 wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
444 val = server->ops->get_credits_field(server, optype);
445 /* Since an echo is already inflight, no need to wait to send another */
446 if (*val <= 0 && optype == CIFS_ECHO_OP)
448 return wait_for_free_credits(server, timeout, val);
451 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
452 struct mid_q_entry **ppmidQ)
454 if (ses->server->tcpStatus == CifsExiting) {
458 if (ses->server->tcpStatus == CifsNeedReconnect) {
459 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
463 if (ses->status == CifsNew) {
464 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
465 (in_buf->Command != SMB_COM_NEGOTIATE))
467 /* else ok - we are setting up session */
470 if (ses->status == CifsExiting) {
471 /* check if SMB session is bad because we are setting it up */
472 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
474 /* else ok - we are shutting down session */
477 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
480 spin_lock(&GlobalMid_Lock);
481 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
482 spin_unlock(&GlobalMid_Lock);
487 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
491 error = wait_event_freezekillable_unsafe(server->response_q,
492 midQ->mid_state != MID_REQUEST_SUBMITTED);
500 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
503 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
504 struct mid_q_entry *mid;
506 /* enable signing if server requires it */
508 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
510 mid = AllocMidQEntry(hdr, server);
512 return ERR_PTR(-ENOMEM);
514 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
516 DeleteMidQEntry(mid);
524 * Send a SMB request and set the callback function in the mid to handle
525 * the result. Caller is responsible for dealing with timeouts.
528 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
529 mid_receive_t *receive, mid_callback_t *callback,
530 void *cbdata, const int flags)
532 int rc, timeout, optype;
533 struct mid_q_entry *mid;
535 timeout = flags & CIFS_TIMEOUT_MASK;
536 optype = flags & CIFS_OP_MASK;
538 rc = wait_for_free_request(server, timeout, optype);
542 mutex_lock(&server->srv_mutex);
543 mid = server->ops->setup_async_request(server, rqst);
545 mutex_unlock(&server->srv_mutex);
546 add_credits(server, 1, optype);
547 wake_up(&server->request_q);
551 mid->receive = receive;
552 mid->callback = callback;
553 mid->callback_data = cbdata;
554 mid->mid_state = MID_REQUEST_SUBMITTED;
556 /* put it on the pending_mid_q */
557 spin_lock(&GlobalMid_Lock);
558 list_add_tail(&mid->qhead, &server->pending_mid_q);
559 spin_unlock(&GlobalMid_Lock);
562 cifs_in_send_inc(server);
563 rc = smb_send_rqst(server, rqst);
564 cifs_in_send_dec(server);
565 cifs_save_when_sent(mid);
568 server->sequence_number -= 2;
569 mutex_unlock(&server->srv_mutex);
574 cifs_delete_mid(mid);
575 add_credits(server, 1, optype);
576 wake_up(&server->request_q);
582 * Send an SMB Request. No response info (other than return code)
583 * needs to be parsed.
585 * flags indicate the type of request buffer and how long to wait
586 * and whether to log NT STATUS code (error) before mapping it to POSIX error
590 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
591 char *in_buf, int flags)
597 iov[0].iov_base = in_buf;
598 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
599 flags |= CIFS_NO_RESP;
600 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
601 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
607 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
611 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
612 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
614 spin_lock(&GlobalMid_Lock);
615 switch (mid->mid_state) {
616 case MID_RESPONSE_RECEIVED:
617 spin_unlock(&GlobalMid_Lock);
619 case MID_RETRY_NEEDED:
622 case MID_RESPONSE_MALFORMED:
629 list_del_init(&mid->qhead);
630 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
631 __func__, mid->mid, mid->mid_state);
634 spin_unlock(&GlobalMid_Lock);
636 DeleteMidQEntry(mid);
641 send_cancel(struct TCP_Server_Info *server, void *buf, struct mid_q_entry *mid)
643 return server->ops->send_cancel ?
644 server->ops->send_cancel(server, buf, mid) : 0;
648 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
651 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
653 dump_smb(mid->resp_buf, min_t(u32, 92, len));
655 /* convert the length into a more usable form */
659 struct smb_rqst rqst = { .rq_iov = &iov,
662 iov.iov_base = mid->resp_buf;
664 /* FIXME: add code to kill session */
665 rc = cifs_verify_signature(&rqst, server,
666 mid->sequence_number);
668 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
672 /* BB special case reconnect tid and uid here? */
673 return map_smb_to_linux_error(mid->resp_buf, log_error);
677 cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
680 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
681 struct mid_q_entry *mid;
683 rc = allocate_mid(ses, hdr, &mid);
686 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
688 cifs_delete_mid(mid);
695 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
696 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
701 struct mid_q_entry *midQ;
702 char *buf = iov[0].iov_base;
703 unsigned int credits = 1;
704 struct smb_rqst rqst = { .rq_iov = iov,
707 timeout = flags & CIFS_TIMEOUT_MASK;
708 optype = flags & CIFS_OP_MASK;
710 *resp_buf_type = CIFS_NO_BUFFER; /* no response buf yet */
712 if ((ses == NULL) || (ses->server == NULL)) {
713 cifs_small_buf_release(buf);
714 cifs_dbg(VFS, "Null session\n");
718 if (ses->server->tcpStatus == CifsExiting) {
719 cifs_small_buf_release(buf);
724 * Ensure that we do not send more than 50 overlapping requests
725 * to the same server. We may make this configurable later or
729 rc = wait_for_free_request(ses->server, timeout, optype);
731 cifs_small_buf_release(buf);
736 * Make sure that we sign in the same order that we send on this socket
737 * and avoid races inside tcp sendmsg code that could cause corruption
741 mutex_lock(&ses->server->srv_mutex);
743 midQ = ses->server->ops->setup_request(ses, &rqst);
745 mutex_unlock(&ses->server->srv_mutex);
746 cifs_small_buf_release(buf);
747 /* Update # of requests on wire to server */
748 add_credits(ses->server, 1, optype);
749 return PTR_ERR(midQ);
752 midQ->mid_state = MID_REQUEST_SUBMITTED;
753 cifs_in_send_inc(ses->server);
754 rc = smb_sendv(ses->server, iov, n_vec);
755 cifs_in_send_dec(ses->server);
756 cifs_save_when_sent(midQ);
759 ses->server->sequence_number -= 2;
760 mutex_unlock(&ses->server->srv_mutex);
763 cifs_small_buf_release(buf);
767 if (timeout == CIFS_ASYNC_OP) {
768 cifs_small_buf_release(buf);
772 rc = wait_for_response(ses->server, midQ);
774 send_cancel(ses->server, buf, midQ);
775 spin_lock(&GlobalMid_Lock);
776 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
777 midQ->callback = DeleteMidQEntry;
778 spin_unlock(&GlobalMid_Lock);
779 cifs_small_buf_release(buf);
780 add_credits(ses->server, 1, optype);
783 spin_unlock(&GlobalMid_Lock);
786 cifs_small_buf_release(buf);
788 rc = cifs_sync_mid_result(midQ, ses->server);
790 add_credits(ses->server, 1, optype);
794 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
796 cifs_dbg(FYI, "Bad MID state?\n");
800 buf = (char *)midQ->resp_buf;
801 iov[0].iov_base = buf;
802 iov[0].iov_len = get_rfc1002_length(buf) + 4;
804 *resp_buf_type = CIFS_LARGE_BUFFER;
806 *resp_buf_type = CIFS_SMALL_BUFFER;
808 credits = ses->server->ops->get_credits(midQ);
810 rc = ses->server->ops->check_receive(midQ, ses->server,
811 flags & CIFS_LOG_ERROR);
813 /* mark it so buf will not be freed by cifs_delete_mid */
814 if ((flags & CIFS_NO_RESP) == 0)
815 midQ->resp_buf = NULL;
817 cifs_delete_mid(midQ);
818 add_credits(ses->server, credits, optype);
824 SendReceive(const unsigned int xid, struct cifs_ses *ses,
825 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
826 int *pbytes_returned, const int timeout)
829 struct mid_q_entry *midQ;
832 cifs_dbg(VFS, "Null smb session\n");
835 if (ses->server == NULL) {
836 cifs_dbg(VFS, "Null tcp session\n");
840 if (ses->server->tcpStatus == CifsExiting)
843 /* Ensure that we do not send more than 50 overlapping requests
844 to the same server. We may make this configurable later or
847 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
848 MAX_CIFS_HDR_SIZE - 4) {
849 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
850 be32_to_cpu(in_buf->smb_buf_length));
854 rc = wait_for_free_request(ses->server, timeout, 0);
858 /* make sure that we sign in the same order that we send on this socket
859 and avoid races inside tcp sendmsg code that could cause corruption
862 mutex_lock(&ses->server->srv_mutex);
864 rc = allocate_mid(ses, in_buf, &midQ);
866 mutex_unlock(&ses->server->srv_mutex);
867 /* Update # of requests on wire to server */
868 add_credits(ses->server, 1, 0);
872 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
874 mutex_unlock(&ses->server->srv_mutex);
878 midQ->mid_state = MID_REQUEST_SUBMITTED;
880 cifs_in_send_inc(ses->server);
881 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
882 cifs_in_send_dec(ses->server);
883 cifs_save_when_sent(midQ);
886 ses->server->sequence_number -= 2;
888 mutex_unlock(&ses->server->srv_mutex);
893 if (timeout == CIFS_ASYNC_OP)
896 rc = wait_for_response(ses->server, midQ);
898 send_cancel(ses->server, in_buf, midQ);
899 spin_lock(&GlobalMid_Lock);
900 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
901 /* no longer considered to be "in-flight" */
902 midQ->callback = DeleteMidQEntry;
903 spin_unlock(&GlobalMid_Lock);
904 add_credits(ses->server, 1, 0);
907 spin_unlock(&GlobalMid_Lock);
910 rc = cifs_sync_mid_result(midQ, ses->server);
912 add_credits(ses->server, 1, 0);
916 if (!midQ->resp_buf || !out_buf ||
917 midQ->mid_state != MID_RESPONSE_RECEIVED) {
919 cifs_dbg(VFS, "Bad MID state?\n");
923 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
924 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
925 rc = cifs_check_receive(midQ, ses->server, 0);
927 cifs_delete_mid(midQ);
928 add_credits(ses->server, 1, 0);
933 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
934 blocking lock to return. */
937 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
938 struct smb_hdr *in_buf,
939 struct smb_hdr *out_buf)
942 struct cifs_ses *ses = tcon->ses;
943 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
945 /* We just modify the current in_buf to change
946 the type of lock from LOCKING_ANDX_SHARED_LOCK
947 or LOCKING_ANDX_EXCLUSIVE_LOCK to
948 LOCKING_ANDX_CANCEL_LOCK. */
950 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
952 pSMB->hdr.Mid = get_next_mid(ses->server);
954 return SendReceive(xid, ses, in_buf, out_buf,
959 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
960 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
961 int *pbytes_returned)
965 struct mid_q_entry *midQ;
966 struct cifs_ses *ses;
968 if (tcon == NULL || tcon->ses == NULL) {
969 cifs_dbg(VFS, "Null smb session\n");
974 if (ses->server == NULL) {
975 cifs_dbg(VFS, "Null tcp session\n");
979 if (ses->server->tcpStatus == CifsExiting)
982 /* Ensure that we do not send more than 50 overlapping requests
983 to the same server. We may make this configurable later or
986 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
987 MAX_CIFS_HDR_SIZE - 4) {
988 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
989 be32_to_cpu(in_buf->smb_buf_length));
993 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
997 /* make sure that we sign in the same order that we send on this socket
998 and avoid races inside tcp sendmsg code that could cause corruption
1001 mutex_lock(&ses->server->srv_mutex);
1003 rc = allocate_mid(ses, in_buf, &midQ);
1005 mutex_unlock(&ses->server->srv_mutex);
1009 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1011 cifs_delete_mid(midQ);
1012 mutex_unlock(&ses->server->srv_mutex);
1016 midQ->mid_state = MID_REQUEST_SUBMITTED;
1017 cifs_in_send_inc(ses->server);
1018 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
1019 cifs_in_send_dec(ses->server);
1020 cifs_save_when_sent(midQ);
1023 ses->server->sequence_number -= 2;
1025 mutex_unlock(&ses->server->srv_mutex);
1028 cifs_delete_mid(midQ);
1032 /* Wait for a reply - allow signals to interrupt. */
1033 rc = wait_event_interruptible(ses->server->response_q,
1034 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1035 ((ses->server->tcpStatus != CifsGood) &&
1036 (ses->server->tcpStatus != CifsNew)));
1038 /* Were we interrupted by a signal ? */
1039 if ((rc == -ERESTARTSYS) &&
1040 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1041 ((ses->server->tcpStatus == CifsGood) ||
1042 (ses->server->tcpStatus == CifsNew))) {
1044 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1045 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1046 blocking lock to return. */
1047 rc = send_cancel(ses->server, in_buf, midQ);
1049 cifs_delete_mid(midQ);
1053 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1054 to cause the blocking lock to return. */
1056 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1058 /* If we get -ENOLCK back the lock may have
1059 already been removed. Don't exit in this case. */
1060 if (rc && rc != -ENOLCK) {
1061 cifs_delete_mid(midQ);
1066 rc = wait_for_response(ses->server, midQ);
1068 send_cancel(ses->server, in_buf, midQ);
1069 spin_lock(&GlobalMid_Lock);
1070 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1071 /* no longer considered to be "in-flight" */
1072 midQ->callback = DeleteMidQEntry;
1073 spin_unlock(&GlobalMid_Lock);
1076 spin_unlock(&GlobalMid_Lock);
1079 /* We got the response - restart system call. */
1083 rc = cifs_sync_mid_result(midQ, ses->server);
1087 /* rcvd frame is ok */
1088 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1090 cifs_dbg(VFS, "Bad MID state?\n");
1094 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1095 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1096 rc = cifs_check_receive(midQ, ses->server, 0);
1098 cifs_delete_mid(midQ);
1099 if (rstart && rc == -EACCES)
1100 return -ERESTARTSYS;