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 flags, unsigned int *instance)
496 optype = flags & CIFS_OP_MASK;
500 credits = server->ops->get_credits_field(server, optype);
501 /* Since an echo is already inflight, no need to wait to send another */
502 if (*credits <= 0 && optype == CIFS_ECHO_OP)
505 spin_lock(&server->req_lock);
506 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP) {
507 /* oplock breaks must not be held up */
510 *instance = server->reconnect_instance;
511 spin_unlock(&server->req_lock);
516 if (*credits < num_credits) {
517 spin_unlock(&server->req_lock);
518 cifs_num_waiters_inc(server);
519 rc = wait_event_killable(server->request_q,
520 has_credits(server, credits, num_credits));
521 cifs_num_waiters_dec(server);
524 spin_lock(&server->req_lock);
526 if (server->tcpStatus == CifsExiting) {
527 spin_unlock(&server->req_lock);
532 * For normal commands, reserve the last MAX_COMPOUND
533 * credits to compound requests.
534 * Otherwise these compounds could be permanently
535 * starved for credits by single-credit requests.
537 * To prevent spinning CPU, block this thread until
538 * there are >MAX_COMPOUND credits available.
539 * But only do this is we already have a lot of
540 * credits in flight to avoid triggering this check
541 * for servers that are slow to hand out credits on
544 if (!optype && num_credits == 1 &&
545 server->in_flight > 2 * MAX_COMPOUND &&
546 *credits <= MAX_COMPOUND) {
547 spin_unlock(&server->req_lock);
548 cifs_num_waiters_inc(server);
549 rc = wait_event_killable(server->request_q,
550 has_credits(server, credits,
552 cifs_num_waiters_dec(server);
555 spin_lock(&server->req_lock);
560 * Can not count locking commands against total
561 * as they are allowed to block on server.
564 /* update # of requests on the wire to server */
565 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
566 *credits -= num_credits;
567 server->in_flight += num_credits;
568 *instance = server->reconnect_instance;
570 spin_unlock(&server->req_lock);
578 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
579 unsigned int *instance)
581 return wait_for_free_credits(server, 1, flags, instance);
585 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
586 unsigned int *num, struct cifs_credits *credits)
590 credits->instance = server->reconnect_instance;
594 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
595 struct mid_q_entry **ppmidQ)
597 if (ses->server->tcpStatus == CifsExiting) {
601 if (ses->server->tcpStatus == CifsNeedReconnect) {
602 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
606 if (ses->status == CifsNew) {
607 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
608 (in_buf->Command != SMB_COM_NEGOTIATE))
610 /* else ok - we are setting up session */
613 if (ses->status == CifsExiting) {
614 /* check if SMB session is bad because we are setting it up */
615 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
617 /* else ok - we are shutting down session */
620 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
623 spin_lock(&GlobalMid_Lock);
624 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
625 spin_unlock(&GlobalMid_Lock);
630 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
634 error = wait_event_freezekillable_unsafe(server->response_q,
635 midQ->mid_state != MID_REQUEST_SUBMITTED);
643 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
646 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
647 struct mid_q_entry *mid;
649 if (rqst->rq_iov[0].iov_len != 4 ||
650 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
651 return ERR_PTR(-EIO);
653 /* enable signing if server requires it */
655 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
657 mid = AllocMidQEntry(hdr, server);
659 return ERR_PTR(-ENOMEM);
661 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
663 DeleteMidQEntry(mid);
671 * Send a SMB request and set the callback function in the mid to handle
672 * the result. Caller is responsible for dealing with timeouts.
675 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
676 mid_receive_t *receive, mid_callback_t *callback,
677 mid_handle_t *handle, void *cbdata, const int flags,
678 const struct cifs_credits *exist_credits)
681 struct mid_q_entry *mid;
682 struct cifs_credits credits = { .value = 0, .instance = 0 };
683 unsigned int instance;
686 optype = flags & CIFS_OP_MASK;
688 if ((flags & CIFS_HAS_CREDITS) == 0) {
689 rc = wait_for_free_request(server, flags, &instance);
693 credits.instance = instance;
695 instance = exist_credits->instance;
697 mutex_lock(&server->srv_mutex);
700 * We can't use credits obtained from the previous session to send this
701 * request. Check if there were reconnects after we obtained credits and
702 * return -EAGAIN in such cases to let callers handle it.
704 if (instance != server->reconnect_instance) {
705 mutex_unlock(&server->srv_mutex);
706 add_credits_and_wake_if(server, &credits, optype);
710 mid = server->ops->setup_async_request(server, rqst);
712 mutex_unlock(&server->srv_mutex);
713 add_credits_and_wake_if(server, &credits, optype);
717 mid->receive = receive;
718 mid->callback = callback;
719 mid->callback_data = cbdata;
720 mid->handle = handle;
721 mid->mid_state = MID_REQUEST_SUBMITTED;
723 /* put it on the pending_mid_q */
724 spin_lock(&GlobalMid_Lock);
725 list_add_tail(&mid->qhead, &server->pending_mid_q);
726 spin_unlock(&GlobalMid_Lock);
729 * Need to store the time in mid before calling I/O. For call_async,
730 * I/O response may come back and free the mid entry on another thread.
732 cifs_save_when_sent(mid);
733 cifs_in_send_inc(server);
734 rc = smb_send_rqst(server, 1, rqst, flags);
735 cifs_in_send_dec(server);
738 revert_current_mid(server, mid->credits);
739 server->sequence_number -= 2;
740 cifs_delete_mid(mid);
743 mutex_unlock(&server->srv_mutex);
748 add_credits_and_wake_if(server, &credits, optype);
754 * Send an SMB Request. No response info (other than return code)
755 * needs to be parsed.
757 * flags indicate the type of request buffer and how long to wait
758 * and whether to log NT STATUS code (error) before mapping it to POSIX error
762 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
763 char *in_buf, int flags)
770 iov[0].iov_base = in_buf;
771 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
772 flags |= CIFS_NO_RESP;
773 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
774 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
780 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
784 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
785 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
787 spin_lock(&GlobalMid_Lock);
788 switch (mid->mid_state) {
789 case MID_RESPONSE_RECEIVED:
790 spin_unlock(&GlobalMid_Lock);
792 case MID_RETRY_NEEDED:
795 case MID_RESPONSE_MALFORMED:
802 list_del_init(&mid->qhead);
803 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
804 __func__, mid->mid, mid->mid_state);
807 spin_unlock(&GlobalMid_Lock);
809 DeleteMidQEntry(mid);
814 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
815 struct mid_q_entry *mid)
817 return server->ops->send_cancel ?
818 server->ops->send_cancel(server, rqst, mid) : 0;
822 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
825 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
827 dump_smb(mid->resp_buf, min_t(u32, 92, len));
829 /* convert the length into a more usable form */
833 struct smb_rqst rqst = { .rq_iov = iov,
836 iov[0].iov_base = mid->resp_buf;
838 iov[1].iov_base = (char *)mid->resp_buf + 4;
839 iov[1].iov_len = len - 4;
840 /* FIXME: add code to kill session */
841 rc = cifs_verify_signature(&rqst, server,
842 mid->sequence_number);
844 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
848 /* BB special case reconnect tid and uid here? */
849 return map_smb_to_linux_error(mid->resp_buf, log_error);
853 cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
856 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
857 struct mid_q_entry *mid;
859 if (rqst->rq_iov[0].iov_len != 4 ||
860 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
861 return ERR_PTR(-EIO);
863 rc = allocate_mid(ses, hdr, &mid);
866 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
868 cifs_delete_mid(mid);
875 cifs_compound_callback(struct mid_q_entry *mid)
877 struct TCP_Server_Info *server = mid->server;
878 struct cifs_credits credits;
880 credits.value = server->ops->get_credits(mid);
881 credits.instance = server->reconnect_instance;
883 add_credits(server, &credits, mid->optype);
887 cifs_compound_last_callback(struct mid_q_entry *mid)
889 cifs_compound_callback(mid);
890 cifs_wake_up_task(mid);
894 cifs_cancelled_callback(struct mid_q_entry *mid)
896 cifs_compound_callback(mid);
897 DeleteMidQEntry(mid);
901 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
902 const int flags, const int num_rqst, struct smb_rqst *rqst,
903 int *resp_buf_type, struct kvec *resp_iov)
905 int i, j, optype, rc = 0;
906 struct mid_q_entry *midQ[MAX_COMPOUND];
907 bool cancelled_mid[MAX_COMPOUND] = {false};
908 struct cifs_credits credits[MAX_COMPOUND] = {
909 { .value = 0, .instance = 0 }
911 unsigned int instance;
912 unsigned int first_instance = 0;
915 optype = flags & CIFS_OP_MASK;
917 for (i = 0; i < num_rqst; i++)
918 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
920 if ((ses == NULL) || (ses->server == NULL)) {
921 cifs_dbg(VFS, "Null session\n");
925 if (ses->server->tcpStatus == CifsExiting)
928 spin_lock(&ses->server->req_lock);
929 if (ses->server->credits < num_rqst) {
931 * Return immediately if not too many requests in flight since
932 * we will likely be stuck on waiting for credits.
934 if (ses->server->in_flight < num_rqst - ses->server->credits) {
935 spin_unlock(&ses->server->req_lock);
939 /* enough credits to send the whole compounded request */
940 ses->server->credits -= num_rqst;
941 ses->server->in_flight += num_rqst;
942 first_instance = ses->server->reconnect_instance;
944 spin_unlock(&ses->server->req_lock);
946 if (first_instance) {
947 cifs_dbg(FYI, "Acquired %d credits at once\n", num_rqst);
948 for (i = 0; i < num_rqst; i++) {
949 credits[i].value = 1;
950 credits[i].instance = first_instance;
956 * There are not enough credits to send the whole compound request but
957 * there are requests in flight that may bring credits from the server.
958 * This approach still leaves the possibility to be stuck waiting for
959 * credits if the server doesn't grant credits to the outstanding
960 * requests. This should be fixed by returning immediately and letting
961 * a caller fallback to sequential commands instead of compounding.
962 * Ensure we obtain 1 credit per request in the compound chain.
964 for (i = 0; i < num_rqst; i++) {
965 rc = wait_for_free_request(ses->server, flags, &instance);
968 credits[i].value = 1;
969 credits[i].instance = instance;
971 * All parts of the compound chain must get credits from
972 * the same session, otherwise we may end up using more
973 * credits than the server granted. If there were
974 * reconnects in between, return -EAGAIN and let callers
978 first_instance = instance;
979 else if (first_instance != instance) {
987 * We haven't sent an SMB packet to the server yet but
988 * we already obtained credits for i requests in the
989 * compound chain - need to return those credits back
990 * for future use. Note that we need to call add_credits
991 * multiple times to match the way we obtained credits
992 * in the first place and to account for in flight
993 * requests correctly.
995 for (j = 0; j < i; j++)
996 add_credits(ses->server, &credits[j], optype);
1003 * Make sure that we sign in the same order that we send on this socket
1004 * and avoid races inside tcp sendmsg code that could cause corruption
1008 mutex_lock(&ses->server->srv_mutex);
1011 * All the parts of the compound chain belong obtained credits from the
1012 * same session (see the appropriate checks above). In the same time
1013 * there might be reconnects after those checks but before we acquired
1014 * the srv_mutex. We can not use credits obtained from the previous
1015 * session to send this request. Check if there were reconnects after
1016 * we obtained credits and return -EAGAIN in such cases to let callers
1019 if (first_instance != ses->server->reconnect_instance) {
1020 mutex_unlock(&ses->server->srv_mutex);
1021 for (j = 0; j < num_rqst; j++)
1022 add_credits(ses->server, &credits[j], optype);
1026 for (i = 0; i < num_rqst; i++) {
1027 midQ[i] = ses->server->ops->setup_request(ses, &rqst[i]);
1028 if (IS_ERR(midQ[i])) {
1029 revert_current_mid(ses->server, i);
1030 for (j = 0; j < i; j++)
1031 cifs_delete_mid(midQ[j]);
1032 mutex_unlock(&ses->server->srv_mutex);
1034 /* Update # of requests on wire to server */
1035 for (j = 0; j < num_rqst; j++)
1036 add_credits(ses->server, &credits[j], optype);
1037 return PTR_ERR(midQ[i]);
1040 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1041 midQ[i]->optype = optype;
1043 * Invoke callback for every part of the compound chain
1044 * to calculate credits properly. Wake up this thread only when
1045 * the last element is received.
1047 if (i < num_rqst - 1)
1048 midQ[i]->callback = cifs_compound_callback;
1050 midQ[i]->callback = cifs_compound_last_callback;
1052 cifs_in_send_inc(ses->server);
1053 rc = smb_send_rqst(ses->server, num_rqst, rqst, flags);
1054 cifs_in_send_dec(ses->server);
1056 for (i = 0; i < num_rqst; i++)
1057 cifs_save_when_sent(midQ[i]);
1060 revert_current_mid(ses->server, num_rqst);
1061 ses->server->sequence_number -= 2;
1064 mutex_unlock(&ses->server->srv_mutex);
1067 /* Sending failed for some reason - return credits back */
1068 for (i = 0; i < num_rqst; i++)
1069 add_credits(ses->server, &credits[i], optype);
1074 * At this point the request is passed to the network stack - we assume
1075 * that any credits taken from the server structure on the client have
1076 * been spent and we can't return them back. Once we receive responses
1077 * we will collect credits granted by the server in the mid callbacks
1078 * and add those credits to the server structure.
1082 * Compounding is never used during session establish.
1084 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
1085 smb311_update_preauth_hash(ses, rqst[0].rq_iov,
1088 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
1091 for (i = 0; i < num_rqst; i++) {
1092 rc = wait_for_response(ses->server, midQ[i]);
1097 for (; i < num_rqst; i++) {
1098 cifs_dbg(VFS, "Cancelling wait for mid %llu cmd: %d\n",
1099 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1100 send_cancel(ses->server, &rqst[i], midQ[i]);
1101 spin_lock(&GlobalMid_Lock);
1102 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1103 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1104 midQ[i]->callback = cifs_cancelled_callback;
1105 cancelled_mid[i] = true;
1106 credits[i].value = 0;
1108 spin_unlock(&GlobalMid_Lock);
1112 for (i = 0; i < num_rqst; i++) {
1116 rc = cifs_sync_mid_result(midQ[i], ses->server);
1118 /* mark this mid as cancelled to not free it below */
1119 cancelled_mid[i] = true;
1123 if (!midQ[i]->resp_buf ||
1124 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1126 cifs_dbg(FYI, "Bad MID state?\n");
1130 buf = (char *)midQ[i]->resp_buf;
1131 resp_iov[i].iov_base = buf;
1132 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1133 ses->server->vals->header_preamble_size;
1135 if (midQ[i]->large_buf)
1136 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1138 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1140 rc = ses->server->ops->check_receive(midQ[i], ses->server,
1141 flags & CIFS_LOG_ERROR);
1143 /* mark it so buf will not be freed by cifs_delete_mid */
1144 if ((flags & CIFS_NO_RESP) == 0)
1145 midQ[i]->resp_buf = NULL;
1150 * Compounding is never used during session establish.
1152 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
1154 .iov_base = resp_iov[0].iov_base,
1155 .iov_len = resp_iov[0].iov_len
1157 smb311_update_preauth_hash(ses, &iov, 1);
1162 * This will dequeue all mids. After this it is important that the
1163 * demultiplex_thread will not process any of these mids any futher.
1164 * This is prevented above by using a noop callback that will not
1165 * wake this thread except for the very last PDU.
1167 for (i = 0; i < num_rqst; i++) {
1168 if (!cancelled_mid[i])
1169 cifs_delete_mid(midQ[i]);
1176 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1177 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1178 struct kvec *resp_iov)
1180 return compound_send_recv(xid, ses, flags, 1, rqst, resp_buf_type,
1185 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1186 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1187 const int flags, struct kvec *resp_iov)
1189 struct smb_rqst rqst;
1190 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1193 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1194 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1197 /* otherwise cifs_send_recv below sets resp_buf_type */
1198 *resp_buf_type = CIFS_NO_BUFFER;
1204 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1205 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1207 new_iov[0].iov_base = new_iov[1].iov_base;
1208 new_iov[0].iov_len = 4;
1209 new_iov[1].iov_base += 4;
1210 new_iov[1].iov_len -= 4;
1212 memset(&rqst, 0, sizeof(struct smb_rqst));
1213 rqst.rq_iov = new_iov;
1214 rqst.rq_nvec = n_vec + 1;
1216 rc = cifs_send_recv(xid, ses, &rqst, resp_buf_type, flags, resp_iov);
1217 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1223 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1224 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1225 int *pbytes_returned, const int flags)
1228 struct mid_q_entry *midQ;
1229 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1230 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1231 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1232 struct cifs_credits credits = { .value = 1, .instance = 0 };
1235 cifs_dbg(VFS, "Null smb session\n");
1238 if (ses->server == NULL) {
1239 cifs_dbg(VFS, "Null tcp session\n");
1243 if (ses->server->tcpStatus == CifsExiting)
1246 /* Ensure that we do not send more than 50 overlapping requests
1247 to the same server. We may make this configurable later or
1250 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1251 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1256 rc = wait_for_free_request(ses->server, flags, &credits.instance);
1260 /* make sure that we sign in the same order that we send on this socket
1261 and avoid races inside tcp sendmsg code that could cause corruption
1264 mutex_lock(&ses->server->srv_mutex);
1266 rc = allocate_mid(ses, in_buf, &midQ);
1268 mutex_unlock(&ses->server->srv_mutex);
1269 /* Update # of requests on wire to server */
1270 add_credits(ses->server, &credits, 0);
1274 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1276 mutex_unlock(&ses->server->srv_mutex);
1280 midQ->mid_state = MID_REQUEST_SUBMITTED;
1282 cifs_in_send_inc(ses->server);
1283 rc = smb_send(ses->server, in_buf, len);
1284 cifs_in_send_dec(ses->server);
1285 cifs_save_when_sent(midQ);
1288 ses->server->sequence_number -= 2;
1290 mutex_unlock(&ses->server->srv_mutex);
1295 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_ASYNC_OP)
1298 rc = wait_for_response(ses->server, midQ);
1300 send_cancel(ses->server, &rqst, midQ);
1301 spin_lock(&GlobalMid_Lock);
1302 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1303 /* no longer considered to be "in-flight" */
1304 midQ->callback = DeleteMidQEntry;
1305 spin_unlock(&GlobalMid_Lock);
1306 add_credits(ses->server, &credits, 0);
1309 spin_unlock(&GlobalMid_Lock);
1312 rc = cifs_sync_mid_result(midQ, ses->server);
1314 add_credits(ses->server, &credits, 0);
1318 if (!midQ->resp_buf || !out_buf ||
1319 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1321 cifs_dbg(VFS, "Bad MID state?\n");
1325 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1326 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1327 rc = cifs_check_receive(midQ, ses->server, 0);
1329 cifs_delete_mid(midQ);
1330 add_credits(ses->server, &credits, 0);
1335 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1336 blocking lock to return. */
1339 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1340 struct smb_hdr *in_buf,
1341 struct smb_hdr *out_buf)
1344 struct cifs_ses *ses = tcon->ses;
1345 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1347 /* We just modify the current in_buf to change
1348 the type of lock from LOCKING_ANDX_SHARED_LOCK
1349 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1350 LOCKING_ANDX_CANCEL_LOCK. */
1352 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1354 pSMB->hdr.Mid = get_next_mid(ses->server);
1356 return SendReceive(xid, ses, in_buf, out_buf,
1357 &bytes_returned, 0);
1361 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1362 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1363 int *pbytes_returned)
1367 struct mid_q_entry *midQ;
1368 struct cifs_ses *ses;
1369 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1370 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1371 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1372 unsigned int instance;
1374 if (tcon == NULL || tcon->ses == NULL) {
1375 cifs_dbg(VFS, "Null smb session\n");
1380 if (ses->server == NULL) {
1381 cifs_dbg(VFS, "Null tcp session\n");
1385 if (ses->server->tcpStatus == CifsExiting)
1388 /* Ensure that we do not send more than 50 overlapping requests
1389 to the same server. We may make this configurable later or
1392 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1393 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1398 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, &instance);
1402 /* make sure that we sign in the same order that we send on this socket
1403 and avoid races inside tcp sendmsg code that could cause corruption
1406 mutex_lock(&ses->server->srv_mutex);
1408 rc = allocate_mid(ses, in_buf, &midQ);
1410 mutex_unlock(&ses->server->srv_mutex);
1414 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1416 cifs_delete_mid(midQ);
1417 mutex_unlock(&ses->server->srv_mutex);
1421 midQ->mid_state = MID_REQUEST_SUBMITTED;
1422 cifs_in_send_inc(ses->server);
1423 rc = smb_send(ses->server, in_buf, len);
1424 cifs_in_send_dec(ses->server);
1425 cifs_save_when_sent(midQ);
1428 ses->server->sequence_number -= 2;
1430 mutex_unlock(&ses->server->srv_mutex);
1433 cifs_delete_mid(midQ);
1437 /* Wait for a reply - allow signals to interrupt. */
1438 rc = wait_event_interruptible(ses->server->response_q,
1439 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1440 ((ses->server->tcpStatus != CifsGood) &&
1441 (ses->server->tcpStatus != CifsNew)));
1443 /* Were we interrupted by a signal ? */
1444 if ((rc == -ERESTARTSYS) &&
1445 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1446 ((ses->server->tcpStatus == CifsGood) ||
1447 (ses->server->tcpStatus == CifsNew))) {
1449 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1450 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1451 blocking lock to return. */
1452 rc = send_cancel(ses->server, &rqst, midQ);
1454 cifs_delete_mid(midQ);
1458 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1459 to cause the blocking lock to return. */
1461 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1463 /* If we get -ENOLCK back the lock may have
1464 already been removed. Don't exit in this case. */
1465 if (rc && rc != -ENOLCK) {
1466 cifs_delete_mid(midQ);
1471 rc = wait_for_response(ses->server, midQ);
1473 send_cancel(ses->server, &rqst, midQ);
1474 spin_lock(&GlobalMid_Lock);
1475 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1476 /* no longer considered to be "in-flight" */
1477 midQ->callback = DeleteMidQEntry;
1478 spin_unlock(&GlobalMid_Lock);
1481 spin_unlock(&GlobalMid_Lock);
1484 /* We got the response - restart system call. */
1488 rc = cifs_sync_mid_result(midQ, ses->server);
1492 /* rcvd frame is ok */
1493 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1495 cifs_dbg(VFS, "Bad MID state?\n");
1499 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1500 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1501 rc = cifs_check_receive(midQ, ses->server, 0);
1503 cifs_delete_mid(midQ);
1504 if (rstart && rc == -EACCES)
1505 return -ERESTARTSYS;