4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 * Jeremy Allison (jra@samba.org) 2006.
8 * This library is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU Lesser General Public License as published
10 * by the Free Software Foundation; either version 2.1 of the License, or
11 * (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
16 * the GNU Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this library; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/list.h>
25 #include <linux/gfp.h>
26 #include <linux/wait.h>
27 #include <linux/net.h>
28 #include <linux/delay.h>
29 #include <linux/freezer.h>
30 #include <linux/tcp.h>
31 #include <linux/bvec.h>
32 #include <linux/highmem.h>
33 #include <linux/uaccess.h>
34 #include <asm/processor.h>
35 #include <linux/mempool.h>
36 #include <linux/signal.h>
39 #include "cifsproto.h"
40 #include "cifs_debug.h"
41 #include "smb2proto.h"
42 #include "smbdirect.h"
44 /* Max number of iovectors we can use off the stack when sending requests. */
45 #define CIFS_MAX_IOV_SIZE 8
48 cifs_wake_up_task(struct mid_q_entry *mid)
50 wake_up_process(mid->callback_data);
54 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
56 struct mid_q_entry *temp;
59 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
63 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
64 memset(temp, 0, sizeof(struct mid_q_entry));
65 kref_init(&temp->refcount);
66 temp->mid = get_mid(smb_buffer);
67 temp->pid = current->pid;
68 temp->command = cpu_to_le16(smb_buffer->Command);
69 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
70 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
71 /* when mid allocated can be before when sent */
72 temp->when_alloc = jiffies;
73 temp->server = server;
76 * The default is for the mid to be synchronous, so the
77 * default callback just wakes up the current task.
79 temp->callback = cifs_wake_up_task;
80 temp->callback_data = current;
82 atomic_inc(&midCount);
83 temp->mid_state = MID_REQUEST_ALLOCATED;
87 static void _cifs_mid_q_entry_release(struct kref *refcount)
89 struct mid_q_entry *mid = container_of(refcount, struct mid_q_entry,
92 mempool_free(mid, cifs_mid_poolp);
95 void cifs_mid_q_entry_release(struct mid_q_entry *midEntry)
97 spin_lock(&GlobalMid_Lock);
98 kref_put(&midEntry->refcount, _cifs_mid_q_entry_release);
99 spin_unlock(&GlobalMid_Lock);
103 DeleteMidQEntry(struct mid_q_entry *midEntry)
105 #ifdef CONFIG_CIFS_STATS2
106 __le16 command = midEntry->server->vals->lock_cmd;
109 midEntry->mid_state = MID_FREE;
110 atomic_dec(&midCount);
111 if (midEntry->large_buf)
112 cifs_buf_release(midEntry->resp_buf);
114 cifs_small_buf_release(midEntry->resp_buf);
115 #ifdef CONFIG_CIFS_STATS2
118 * commands taking longer than one second (default) can be indications
119 * that something is wrong, unless it is quite a slow link or a very
120 * busy server. Note that this calc is unlikely or impossible to wrap
121 * as long as slow_rsp_threshold is not set way above recommended max
122 * value (32767 ie 9 hours) and is generally harmless even if wrong
123 * since only affects debug counters - so leaving the calc as simple
124 * comparison rather than doing multiple conversions and overflow
127 if ((slow_rsp_threshold != 0) &&
128 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
129 (midEntry->command != command)) {
131 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
132 * NB: le16_to_cpu returns unsigned so can not be negative below
134 if (le16_to_cpu(midEntry->command) < NUMBER_OF_SMB2_COMMANDS)
135 cifs_stats_inc(&midEntry->server->smb2slowcmd[le16_to_cpu(midEntry->command)]);
137 trace_smb3_slow_rsp(le16_to_cpu(midEntry->command),
138 midEntry->mid, midEntry->pid,
139 midEntry->when_sent, midEntry->when_received);
140 if (cifsFYI & CIFS_TIMER) {
141 pr_debug(" CIFS slow rsp: cmd %d mid %llu",
142 midEntry->command, midEntry->mid);
143 cifs_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
144 now - midEntry->when_alloc,
145 now - midEntry->when_sent,
146 now - midEntry->when_received);
150 cifs_mid_q_entry_release(midEntry);
154 cifs_delete_mid(struct mid_q_entry *mid)
156 spin_lock(&GlobalMid_Lock);
157 list_del_init(&mid->qhead);
158 mid->mid_flags |= MID_DELETED;
159 spin_unlock(&GlobalMid_Lock);
161 DeleteMidQEntry(mid);
165 * smb_send_kvec - send an array of kvecs to the server
166 * @server: Server to send the data to
167 * @smb_msg: Message to send
168 * @sent: amount of data sent on socket is stored here
170 * Our basic "send data to server" function. Should be called with srv_mutex
171 * held. The caller is responsible for handling the results.
174 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
179 struct socket *ssocket = server->ssocket;
183 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
184 smb_msg->msg_namelen = sizeof(struct sockaddr);
185 smb_msg->msg_control = NULL;
186 smb_msg->msg_controllen = 0;
187 if (server->noblocksnd)
188 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
190 smb_msg->msg_flags = MSG_NOSIGNAL;
192 while (msg_data_left(smb_msg)) {
194 * If blocking send, we try 3 times, since each can block
195 * for 5 seconds. For nonblocking we have to try more
196 * but wait increasing amounts of time allowing time for
197 * socket to clear. The overall time we wait in either
198 * case to send on the socket is about 15 seconds.
199 * Similarly we wait for 15 seconds for a response from
200 * the server in SendReceive[2] for the server to send
201 * a response back for most types of requests (except
202 * SMB Write past end of file which can be slow, and
203 * blocking lock operations). NFS waits slightly longer
204 * than CIFS, but this can make it take longer for
205 * nonresponsive servers to be detected and 15 seconds
206 * is more than enough time for modern networks to
207 * send a packet. In most cases if we fail to send
208 * after the retries we will kill the socket and
209 * reconnect which may clear the network problem.
211 rc = sock_sendmsg(ssocket, smb_msg);
215 (!server->noblocksnd && (retries > 2))) {
216 cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
220 msleep(1 << retries);
228 /* should never happen, letting socket clear before
229 retrying is our only obvious option here */
230 cifs_dbg(VFS, "tcp sent no data\n");
235 /* send was at least partially successful */
237 retries = 0; /* in case we get ENOSPC on the next send */
243 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
248 unsigned long buflen = 0;
250 if (server->vals->header_preamble_size == 0 &&
251 rqst->rq_nvec >= 2 && rqst->rq_iov[0].iov_len == 4) {
252 iov = &rqst->rq_iov[1];
253 nvec = rqst->rq_nvec - 1;
256 nvec = rqst->rq_nvec;
259 /* total up iov array first */
260 for (i = 0; i < nvec; i++)
261 buflen += iov[i].iov_len;
264 * Add in the page array if there is one. The caller needs to make
265 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
266 * multiple pages ends at page boundary, rq_tailsz needs to be set to
269 if (rqst->rq_npages) {
270 if (rqst->rq_npages == 1)
271 buflen += rqst->rq_tailsz;
274 * If there is more than one page, calculate the
275 * buffer length based on rq_offset and rq_tailsz
277 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
279 buflen += rqst->rq_tailsz;
287 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
288 struct smb_rqst *rqst)
293 unsigned int send_length = 0;
295 sigset_t mask, oldmask;
296 size_t total_len = 0, sent, size;
297 struct socket *ssocket = server->ssocket;
298 struct msghdr smb_msg;
300 __be32 rfc1002_marker;
302 if (cifs_rdma_enabled(server) && server->smbd_conn) {
303 rc = smbd_send(server, rqst);
310 if (signal_pending(current)) {
311 cifs_dbg(FYI, "signal is pending before sending any data\n");
315 /* cork the socket */
316 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
317 (char *)&val, sizeof(val));
319 for (j = 0; j < num_rqst; j++)
320 send_length += smb_rqst_len(server, &rqst[j]);
321 rfc1002_marker = cpu_to_be32(send_length);
324 * We should not allow signals to interrupt the network send because
325 * any partial send will cause session reconnects thus increasing
326 * latency of system calls and overload a server with unnecessary
331 sigprocmask(SIG_BLOCK, &mask, &oldmask);
333 /* Generate a rfc1002 marker for SMB2+ */
334 if (server->vals->header_preamble_size == 0) {
336 .iov_base = &rfc1002_marker,
339 iov_iter_kvec(&smb_msg.msg_iter, WRITE, &hiov, 1, 4);
340 rc = smb_send_kvec(server, &smb_msg, &sent);
348 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
350 for (j = 0; j < num_rqst; j++) {
351 iov = rqst[j].rq_iov;
352 n_vec = rqst[j].rq_nvec;
355 for (i = 0; i < n_vec; i++) {
356 dump_smb(iov[i].iov_base, iov[i].iov_len);
357 size += iov[i].iov_len;
360 iov_iter_kvec(&smb_msg.msg_iter, WRITE, iov, n_vec, size);
362 rc = smb_send_kvec(server, &smb_msg, &sent);
368 /* now walk the page array and send each page in it */
369 for (i = 0; i < rqst[j].rq_npages; i++) {
372 bvec.bv_page = rqst[j].rq_pages[i];
373 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
376 iov_iter_bvec(&smb_msg.msg_iter, WRITE,
377 &bvec, 1, bvec.bv_len);
378 rc = smb_send_kvec(server, &smb_msg, &sent);
387 sigprocmask(SIG_SETMASK, &oldmask, NULL);
390 * If signal is pending but we have already sent the whole packet to
391 * the server we need to return success status to allow a corresponding
392 * mid entry to be kept in the pending requests queue thus allowing
393 * to handle responses from the server by the client.
395 * If only part of the packet has been sent there is no need to hide
396 * interrupt because the session will be reconnected anyway, so there
397 * won't be any response from the server to handle.
400 if (signal_pending(current) && (total_len != send_length)) {
401 cifs_dbg(FYI, "signal is pending after attempt to send\n");
407 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
408 (char *)&val, sizeof(val));
410 if ((total_len > 0) && (total_len != send_length)) {
411 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
412 send_length, total_len);
414 * If we have only sent part of an SMB then the next SMB could
415 * be taken as the remainder of this one. We need to kill the
416 * socket so the server throws away the partial SMB
418 server->tcpStatus = CifsNeedReconnect;
419 trace_smb3_partial_send_reconnect(server->CurrentMid,
423 if (rc < 0 && rc != -EINTR)
424 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
433 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
434 struct smb_rqst *rqst, int flags)
437 struct smb2_transform_hdr tr_hdr;
438 struct smb_rqst cur_rqst[MAX_COMPOUND];
441 if (!(flags & CIFS_TRANSFORM_REQ))
442 return __smb_send_rqst(server, num_rqst, rqst);
444 if (num_rqst > MAX_COMPOUND - 1)
447 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
448 memset(&iov, 0, sizeof(iov));
449 memset(&tr_hdr, 0, sizeof(tr_hdr));
451 iov.iov_base = &tr_hdr;
452 iov.iov_len = sizeof(tr_hdr);
453 cur_rqst[0].rq_iov = &iov;
454 cur_rqst[0].rq_nvec = 1;
456 if (!server->ops->init_transform_rq) {
457 cifs_dbg(VFS, "Encryption requested but transform callback "
462 rc = server->ops->init_transform_rq(server, num_rqst + 1,
467 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
468 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
473 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
474 unsigned int smb_buf_length)
477 struct smb_rqst rqst = { .rq_iov = iov,
480 iov[0].iov_base = smb_buffer;
482 iov[1].iov_base = (char *)smb_buffer + 4;
483 iov[1].iov_len = smb_buf_length;
485 return __smb_send_rqst(server, 1, &rqst);
489 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
490 const int timeout, const int flags,
491 unsigned int *instance)
499 t = MAX_JIFFY_OFFSET;
501 t = msecs_to_jiffies(timeout);
503 optype = flags & CIFS_OP_MASK;
507 credits = server->ops->get_credits_field(server, optype);
508 /* Since an echo is already inflight, no need to wait to send another */
509 if (*credits <= 0 && optype == CIFS_ECHO_OP)
512 spin_lock(&server->req_lock);
513 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP) {
514 /* oplock breaks must not be held up */
517 *instance = server->reconnect_instance;
518 spin_unlock(&server->req_lock);
523 if (*credits < num_credits) {
524 spin_unlock(&server->req_lock);
525 cifs_num_waiters_inc(server);
526 rc = wait_event_killable_timeout(server->request_q,
527 has_credits(server, credits, num_credits), t);
528 cifs_num_waiters_dec(server);
530 cifs_dbg(VFS, "wait timed out after %d ms\n",
534 if (rc == -ERESTARTSYS)
536 spin_lock(&server->req_lock);
538 if (server->tcpStatus == CifsExiting) {
539 spin_unlock(&server->req_lock);
544 * For normal commands, reserve the last MAX_COMPOUND
545 * credits to compound requests.
546 * Otherwise these compounds could be permanently
547 * starved for credits by single-credit requests.
549 * To prevent spinning CPU, block this thread until
550 * there are >MAX_COMPOUND credits available.
551 * But only do this is we already have a lot of
552 * credits in flight to avoid triggering this check
553 * for servers that are slow to hand out credits on
556 if (!optype && num_credits == 1 &&
557 server->in_flight > 2 * MAX_COMPOUND &&
558 *credits <= MAX_COMPOUND) {
559 spin_unlock(&server->req_lock);
560 cifs_num_waiters_inc(server);
561 rc = wait_event_killable_timeout(
563 has_credits(server, credits,
566 cifs_num_waiters_dec(server);
568 cifs_dbg(VFS, "wait timed out after %d ms\n",
572 if (rc == -ERESTARTSYS)
574 spin_lock(&server->req_lock);
579 * Can not count locking commands against total
580 * as they are allowed to block on server.
583 /* update # of requests on the wire to server */
584 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
585 *credits -= num_credits;
586 server->in_flight += num_credits;
587 *instance = server->reconnect_instance;
589 spin_unlock(&server->req_lock);
597 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
598 unsigned int *instance)
600 return wait_for_free_credits(server, 1, -1, flags,
605 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
606 unsigned int *num, struct cifs_credits *credits)
610 credits->instance = server->reconnect_instance;
614 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
615 struct mid_q_entry **ppmidQ)
617 if (ses->server->tcpStatus == CifsExiting) {
621 if (ses->server->tcpStatus == CifsNeedReconnect) {
622 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
626 if (ses->status == CifsNew) {
627 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
628 (in_buf->Command != SMB_COM_NEGOTIATE))
630 /* else ok - we are setting up session */
633 if (ses->status == CifsExiting) {
634 /* check if SMB session is bad because we are setting it up */
635 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
637 /* else ok - we are shutting down session */
640 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
643 spin_lock(&GlobalMid_Lock);
644 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
645 spin_unlock(&GlobalMid_Lock);
650 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
654 error = wait_event_freezekillable_unsafe(server->response_q,
655 midQ->mid_state != MID_REQUEST_SUBMITTED);
663 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
666 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
667 struct mid_q_entry *mid;
669 if (rqst->rq_iov[0].iov_len != 4 ||
670 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
671 return ERR_PTR(-EIO);
673 /* enable signing if server requires it */
675 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
677 mid = AllocMidQEntry(hdr, server);
679 return ERR_PTR(-ENOMEM);
681 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
683 DeleteMidQEntry(mid);
691 * Send a SMB request and set the callback function in the mid to handle
692 * the result. Caller is responsible for dealing with timeouts.
695 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
696 mid_receive_t *receive, mid_callback_t *callback,
697 mid_handle_t *handle, void *cbdata, const int flags,
698 const struct cifs_credits *exist_credits)
701 struct mid_q_entry *mid;
702 struct cifs_credits credits = { .value = 0, .instance = 0 };
703 unsigned int instance;
706 optype = flags & CIFS_OP_MASK;
708 if ((flags & CIFS_HAS_CREDITS) == 0) {
709 rc = wait_for_free_request(server, flags, &instance);
713 credits.instance = instance;
715 instance = exist_credits->instance;
717 mutex_lock(&server->srv_mutex);
720 * We can't use credits obtained from the previous session to send this
721 * request. Check if there were reconnects after we obtained credits and
722 * return -EAGAIN in such cases to let callers handle it.
724 if (instance != server->reconnect_instance) {
725 mutex_unlock(&server->srv_mutex);
726 add_credits_and_wake_if(server, &credits, optype);
730 mid = server->ops->setup_async_request(server, rqst);
732 mutex_unlock(&server->srv_mutex);
733 add_credits_and_wake_if(server, &credits, optype);
737 mid->receive = receive;
738 mid->callback = callback;
739 mid->callback_data = cbdata;
740 mid->handle = handle;
741 mid->mid_state = MID_REQUEST_SUBMITTED;
743 /* put it on the pending_mid_q */
744 spin_lock(&GlobalMid_Lock);
745 list_add_tail(&mid->qhead, &server->pending_mid_q);
746 spin_unlock(&GlobalMid_Lock);
749 * Need to store the time in mid before calling I/O. For call_async,
750 * I/O response may come back and free the mid entry on another thread.
752 cifs_save_when_sent(mid);
753 cifs_in_send_inc(server);
754 rc = smb_send_rqst(server, 1, rqst, flags);
755 cifs_in_send_dec(server);
758 revert_current_mid(server, mid->credits);
759 server->sequence_number -= 2;
760 cifs_delete_mid(mid);
763 mutex_unlock(&server->srv_mutex);
768 add_credits_and_wake_if(server, &credits, optype);
774 * Send an SMB Request. No response info (other than return code)
775 * needs to be parsed.
777 * flags indicate the type of request buffer and how long to wait
778 * and whether to log NT STATUS code (error) before mapping it to POSIX error
782 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
783 char *in_buf, int flags)
790 iov[0].iov_base = in_buf;
791 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
792 flags |= CIFS_NO_RESP;
793 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
794 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
800 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
804 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
805 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
807 spin_lock(&GlobalMid_Lock);
808 switch (mid->mid_state) {
809 case MID_RESPONSE_RECEIVED:
810 spin_unlock(&GlobalMid_Lock);
812 case MID_RETRY_NEEDED:
815 case MID_RESPONSE_MALFORMED:
822 list_del_init(&mid->qhead);
823 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
824 __func__, mid->mid, mid->mid_state);
827 spin_unlock(&GlobalMid_Lock);
829 DeleteMidQEntry(mid);
834 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
835 struct mid_q_entry *mid)
837 return server->ops->send_cancel ?
838 server->ops->send_cancel(server, rqst, mid) : 0;
842 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
845 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
847 dump_smb(mid->resp_buf, min_t(u32, 92, len));
849 /* convert the length into a more usable form */
853 struct smb_rqst rqst = { .rq_iov = iov,
856 iov[0].iov_base = mid->resp_buf;
858 iov[1].iov_base = (char *)mid->resp_buf + 4;
859 iov[1].iov_len = len - 4;
860 /* FIXME: add code to kill session */
861 rc = cifs_verify_signature(&rqst, server,
862 mid->sequence_number);
864 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
868 /* BB special case reconnect tid and uid here? */
869 return map_smb_to_linux_error(mid->resp_buf, log_error);
873 cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
876 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
877 struct mid_q_entry *mid;
879 if (rqst->rq_iov[0].iov_len != 4 ||
880 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
881 return ERR_PTR(-EIO);
883 rc = allocate_mid(ses, hdr, &mid);
886 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
888 cifs_delete_mid(mid);
895 cifs_compound_callback(struct mid_q_entry *mid)
897 struct TCP_Server_Info *server = mid->server;
898 struct cifs_credits credits;
900 credits.value = server->ops->get_credits(mid);
901 credits.instance = server->reconnect_instance;
903 add_credits(server, &credits, mid->optype);
907 cifs_compound_last_callback(struct mid_q_entry *mid)
909 cifs_compound_callback(mid);
910 cifs_wake_up_task(mid);
914 cifs_cancelled_callback(struct mid_q_entry *mid)
916 cifs_compound_callback(mid);
917 DeleteMidQEntry(mid);
921 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
922 const int flags, const int num_rqst, struct smb_rqst *rqst,
923 int *resp_buf_type, struct kvec *resp_iov)
925 int i, j, optype, rc = 0;
926 struct mid_q_entry *midQ[MAX_COMPOUND];
927 bool cancelled_mid[MAX_COMPOUND] = {false};
928 struct cifs_credits credits[MAX_COMPOUND] = {
929 { .value = 0, .instance = 0 }
931 unsigned int instance;
932 unsigned int first_instance = 0;
935 optype = flags & CIFS_OP_MASK;
937 for (i = 0; i < num_rqst; i++)
938 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
940 if ((ses == NULL) || (ses->server == NULL)) {
941 cifs_dbg(VFS, "Null session\n");
945 if (ses->server->tcpStatus == CifsExiting)
948 spin_lock(&ses->server->req_lock);
949 if (ses->server->credits < num_rqst) {
951 * Return immediately if not too many requests in flight since
952 * we will likely be stuck on waiting for credits.
954 if (ses->server->in_flight < num_rqst - ses->server->credits) {
955 spin_unlock(&ses->server->req_lock);
959 /* enough credits to send the whole compounded request */
960 ses->server->credits -= num_rqst;
961 ses->server->in_flight += num_rqst;
962 first_instance = ses->server->reconnect_instance;
964 spin_unlock(&ses->server->req_lock);
966 if (first_instance) {
967 cifs_dbg(FYI, "Acquired %d credits at once\n", num_rqst);
968 for (i = 0; i < num_rqst; i++) {
969 credits[i].value = 1;
970 credits[i].instance = first_instance;
976 * There are not enough credits to send the whole compound request but
977 * there are requests in flight that may bring credits from the server.
978 * This approach still leaves the possibility to be stuck waiting for
979 * credits if the server doesn't grant credits to the outstanding
980 * requests. This should be fixed by returning immediately and letting
981 * a caller fallback to sequential commands instead of compounding.
982 * Ensure we obtain 1 credit per request in the compound chain.
984 for (i = 0; i < num_rqst; i++) {
985 rc = wait_for_free_request(ses->server, flags, &instance);
988 credits[i].value = 1;
989 credits[i].instance = instance;
991 * All parts of the compound chain must get credits from
992 * the same session, otherwise we may end up using more
993 * credits than the server granted. If there were
994 * reconnects in between, return -EAGAIN and let callers
998 first_instance = instance;
999 else if (first_instance != instance) {
1007 * We haven't sent an SMB packet to the server yet but
1008 * we already obtained credits for i requests in the
1009 * compound chain - need to return those credits back
1010 * for future use. Note that we need to call add_credits
1011 * multiple times to match the way we obtained credits
1012 * in the first place and to account for in flight
1013 * requests correctly.
1015 for (j = 0; j < i; j++)
1016 add_credits(ses->server, &credits[j], optype);
1023 * Make sure that we sign in the same order that we send on this socket
1024 * and avoid races inside tcp sendmsg code that could cause corruption
1028 mutex_lock(&ses->server->srv_mutex);
1031 * All the parts of the compound chain belong obtained credits from the
1032 * same session (see the appropriate checks above). In the same time
1033 * there might be reconnects after those checks but before we acquired
1034 * the srv_mutex. We can not use credits obtained from the previous
1035 * session to send this request. Check if there were reconnects after
1036 * we obtained credits and return -EAGAIN in such cases to let callers
1039 if (first_instance != ses->server->reconnect_instance) {
1040 mutex_unlock(&ses->server->srv_mutex);
1041 for (j = 0; j < num_rqst; j++)
1042 add_credits(ses->server, &credits[j], optype);
1046 for (i = 0; i < num_rqst; i++) {
1047 midQ[i] = ses->server->ops->setup_request(ses, &rqst[i]);
1048 if (IS_ERR(midQ[i])) {
1049 revert_current_mid(ses->server, i);
1050 for (j = 0; j < i; j++)
1051 cifs_delete_mid(midQ[j]);
1052 mutex_unlock(&ses->server->srv_mutex);
1054 /* Update # of requests on wire to server */
1055 for (j = 0; j < num_rqst; j++)
1056 add_credits(ses->server, &credits[j], optype);
1057 return PTR_ERR(midQ[i]);
1060 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1061 midQ[i]->optype = optype;
1063 * Invoke callback for every part of the compound chain
1064 * to calculate credits properly. Wake up this thread only when
1065 * the last element is received.
1067 if (i < num_rqst - 1)
1068 midQ[i]->callback = cifs_compound_callback;
1070 midQ[i]->callback = cifs_compound_last_callback;
1072 cifs_in_send_inc(ses->server);
1073 rc = smb_send_rqst(ses->server, num_rqst, rqst, flags);
1074 cifs_in_send_dec(ses->server);
1076 for (i = 0; i < num_rqst; i++)
1077 cifs_save_when_sent(midQ[i]);
1080 revert_current_mid(ses->server, num_rqst);
1081 ses->server->sequence_number -= 2;
1084 mutex_unlock(&ses->server->srv_mutex);
1087 /* Sending failed for some reason - return credits back */
1088 for (i = 0; i < num_rqst; i++)
1089 add_credits(ses->server, &credits[i], optype);
1094 * At this point the request is passed to the network stack - we assume
1095 * that any credits taken from the server structure on the client have
1096 * been spent and we can't return them back. Once we receive responses
1097 * we will collect credits granted by the server in the mid callbacks
1098 * and add those credits to the server structure.
1102 * Compounding is never used during session establish.
1104 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
1105 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1108 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
1111 for (i = 0; i < num_rqst; i++) {
1112 rc = wait_for_response(ses->server, midQ[i]);
1117 for (; i < num_rqst; i++) {
1118 cifs_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n",
1119 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1120 send_cancel(ses->server, &rqst[i], midQ[i]);
1121 spin_lock(&GlobalMid_Lock);
1122 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1123 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1124 midQ[i]->callback = cifs_cancelled_callback;
1125 cancelled_mid[i] = true;
1126 credits[i].value = 0;
1128 spin_unlock(&GlobalMid_Lock);
1132 for (i = 0; i < num_rqst; i++) {
1136 rc = cifs_sync_mid_result(midQ[i], ses->server);
1138 /* mark this mid as cancelled to not free it below */
1139 cancelled_mid[i] = true;
1143 if (!midQ[i]->resp_buf ||
1144 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1146 cifs_dbg(FYI, "Bad MID state?\n");
1150 buf = (char *)midQ[i]->resp_buf;
1151 resp_iov[i].iov_base = buf;
1152 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1153 ses->server->vals->header_preamble_size;
1155 if (midQ[i]->large_buf)
1156 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1158 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1160 rc = ses->server->ops->check_receive(midQ[i], ses->server,
1161 flags & CIFS_LOG_ERROR);
1163 /* mark it so buf will not be freed by cifs_delete_mid */
1164 if ((flags & CIFS_NO_RESP) == 0)
1165 midQ[i]->resp_buf = NULL;
1170 * Compounding is never used during session establish.
1172 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
1174 .iov_base = resp_iov[0].iov_base,
1175 .iov_len = resp_iov[0].iov_len
1177 smb311_update_preauth_hash(ses, &iov, 1);
1182 * This will dequeue all mids. After this it is important that the
1183 * demultiplex_thread will not process any of these mids any futher.
1184 * This is prevented above by using a noop callback that will not
1185 * wake this thread except for the very last PDU.
1187 for (i = 0; i < num_rqst; i++) {
1188 if (!cancelled_mid[i])
1189 cifs_delete_mid(midQ[i]);
1196 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1197 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1198 struct kvec *resp_iov)
1200 return compound_send_recv(xid, ses, flags, 1, rqst, resp_buf_type,
1205 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1206 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1207 const int flags, struct kvec *resp_iov)
1209 struct smb_rqst rqst;
1210 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1213 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1214 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1217 /* otherwise cifs_send_recv below sets resp_buf_type */
1218 *resp_buf_type = CIFS_NO_BUFFER;
1224 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1225 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1227 new_iov[0].iov_base = new_iov[1].iov_base;
1228 new_iov[0].iov_len = 4;
1229 new_iov[1].iov_base += 4;
1230 new_iov[1].iov_len -= 4;
1232 memset(&rqst, 0, sizeof(struct smb_rqst));
1233 rqst.rq_iov = new_iov;
1234 rqst.rq_nvec = n_vec + 1;
1236 rc = cifs_send_recv(xid, ses, &rqst, resp_buf_type, flags, resp_iov);
1237 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1243 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1244 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1245 int *pbytes_returned, const int flags)
1248 struct mid_q_entry *midQ;
1249 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1250 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1251 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1252 struct cifs_credits credits = { .value = 1, .instance = 0 };
1255 cifs_dbg(VFS, "Null smb session\n");
1258 if (ses->server == NULL) {
1259 cifs_dbg(VFS, "Null tcp session\n");
1263 if (ses->server->tcpStatus == CifsExiting)
1266 /* Ensure that we do not send more than 50 overlapping requests
1267 to the same server. We may make this configurable later or
1270 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1271 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1276 rc = wait_for_free_request(ses->server, flags, &credits.instance);
1280 /* make sure that we sign in the same order that we send on this socket
1281 and avoid races inside tcp sendmsg code that could cause corruption
1284 mutex_lock(&ses->server->srv_mutex);
1286 rc = allocate_mid(ses, in_buf, &midQ);
1288 mutex_unlock(&ses->server->srv_mutex);
1289 /* Update # of requests on wire to server */
1290 add_credits(ses->server, &credits, 0);
1294 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1296 mutex_unlock(&ses->server->srv_mutex);
1300 midQ->mid_state = MID_REQUEST_SUBMITTED;
1302 cifs_in_send_inc(ses->server);
1303 rc = smb_send(ses->server, in_buf, len);
1304 cifs_in_send_dec(ses->server);
1305 cifs_save_when_sent(midQ);
1308 ses->server->sequence_number -= 2;
1310 mutex_unlock(&ses->server->srv_mutex);
1315 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
1318 rc = wait_for_response(ses->server, midQ);
1320 send_cancel(ses->server, &rqst, midQ);
1321 spin_lock(&GlobalMid_Lock);
1322 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1323 /* no longer considered to be "in-flight" */
1324 midQ->callback = DeleteMidQEntry;
1325 spin_unlock(&GlobalMid_Lock);
1326 add_credits(ses->server, &credits, 0);
1329 spin_unlock(&GlobalMid_Lock);
1332 rc = cifs_sync_mid_result(midQ, ses->server);
1334 add_credits(ses->server, &credits, 0);
1338 if (!midQ->resp_buf || !out_buf ||
1339 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1341 cifs_dbg(VFS, "Bad MID state?\n");
1345 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1346 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1347 rc = cifs_check_receive(midQ, ses->server, 0);
1349 cifs_delete_mid(midQ);
1350 add_credits(ses->server, &credits, 0);
1355 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1356 blocking lock to return. */
1359 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1360 struct smb_hdr *in_buf,
1361 struct smb_hdr *out_buf)
1364 struct cifs_ses *ses = tcon->ses;
1365 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1367 /* We just modify the current in_buf to change
1368 the type of lock from LOCKING_ANDX_SHARED_LOCK
1369 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1370 LOCKING_ANDX_CANCEL_LOCK. */
1372 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1374 pSMB->hdr.Mid = get_next_mid(ses->server);
1376 return SendReceive(xid, ses, in_buf, out_buf,
1377 &bytes_returned, 0);
1381 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1382 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1383 int *pbytes_returned)
1387 struct mid_q_entry *midQ;
1388 struct cifs_ses *ses;
1389 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1390 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1391 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1392 unsigned int instance;
1394 if (tcon == NULL || tcon->ses == NULL) {
1395 cifs_dbg(VFS, "Null smb session\n");
1400 if (ses->server == NULL) {
1401 cifs_dbg(VFS, "Null tcp session\n");
1405 if (ses->server->tcpStatus == CifsExiting)
1408 /* Ensure that we do not send more than 50 overlapping requests
1409 to the same server. We may make this configurable later or
1412 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1413 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1418 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, &instance);
1422 /* make sure that we sign in the same order that we send on this socket
1423 and avoid races inside tcp sendmsg code that could cause corruption
1426 mutex_lock(&ses->server->srv_mutex);
1428 rc = allocate_mid(ses, in_buf, &midQ);
1430 mutex_unlock(&ses->server->srv_mutex);
1434 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1436 cifs_delete_mid(midQ);
1437 mutex_unlock(&ses->server->srv_mutex);
1441 midQ->mid_state = MID_REQUEST_SUBMITTED;
1442 cifs_in_send_inc(ses->server);
1443 rc = smb_send(ses->server, in_buf, len);
1444 cifs_in_send_dec(ses->server);
1445 cifs_save_when_sent(midQ);
1448 ses->server->sequence_number -= 2;
1450 mutex_unlock(&ses->server->srv_mutex);
1453 cifs_delete_mid(midQ);
1457 /* Wait for a reply - allow signals to interrupt. */
1458 rc = wait_event_interruptible(ses->server->response_q,
1459 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1460 ((ses->server->tcpStatus != CifsGood) &&
1461 (ses->server->tcpStatus != CifsNew)));
1463 /* Were we interrupted by a signal ? */
1464 if ((rc == -ERESTARTSYS) &&
1465 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1466 ((ses->server->tcpStatus == CifsGood) ||
1467 (ses->server->tcpStatus == CifsNew))) {
1469 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1470 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1471 blocking lock to return. */
1472 rc = send_cancel(ses->server, &rqst, midQ);
1474 cifs_delete_mid(midQ);
1478 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1479 to cause the blocking lock to return. */
1481 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1483 /* If we get -ENOLCK back the lock may have
1484 already been removed. Don't exit in this case. */
1485 if (rc && rc != -ENOLCK) {
1486 cifs_delete_mid(midQ);
1491 rc = wait_for_response(ses->server, midQ);
1493 send_cancel(ses->server, &rqst, midQ);
1494 spin_lock(&GlobalMid_Lock);
1495 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1496 /* no longer considered to be "in-flight" */
1497 midQ->callback = DeleteMidQEntry;
1498 spin_unlock(&GlobalMid_Lock);
1501 spin_unlock(&GlobalMid_Lock);
1504 /* We got the response - restart system call. */
1508 rc = cifs_sync_mid_result(midQ, ses->server);
1512 /* rcvd frame is ok */
1513 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1515 cifs_dbg(VFS, "Bad MID state?\n");
1519 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1520 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1521 rc = cifs_check_receive(midQ, ses->server, 0);
1523 cifs_delete_mid(midQ);
1524 if (rstart && rc == -EACCES)
1525 return -ERESTARTSYS;