1 // SPDX-License-Identifier: LGPL-2.1
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.
11 #include <linux/list.h>
12 #include <linux/gfp.h>
13 #include <linux/wait.h>
14 #include <linux/net.h>
15 #include <linux/delay.h>
16 #include <linux/freezer.h>
17 #include <linux/tcp.h>
18 #include <linux/bvec.h>
19 #include <linux/highmem.h>
20 #include <linux/uaccess.h>
21 #include <asm/processor.h>
22 #include <linux/mempool.h>
23 #include <linux/sched/signal.h>
24 #include <linux/task_io_accounting_ops.h>
27 #include "cifsproto.h"
28 #include "cifs_debug.h"
29 #include "smb2proto.h"
30 #include "smbdirect.h"
32 /* Max number of iovectors we can use off the stack when sending requests. */
33 #define CIFS_MAX_IOV_SIZE 8
36 cifs_wake_up_task(struct mid_q_entry *mid)
38 if (mid->mid_state == MID_RESPONSE_RECEIVED)
39 mid->mid_state = MID_RESPONSE_READY;
40 wake_up_process(mid->callback_data);
43 static struct mid_q_entry *
44 alloc_mid(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
46 struct mid_q_entry *temp;
49 cifs_dbg(VFS, "%s: null TCP session\n", __func__);
53 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
54 memset(temp, 0, sizeof(struct mid_q_entry));
55 kref_init(&temp->refcount);
56 temp->mid = get_mid(smb_buffer);
57 temp->pid = current->pid;
58 temp->command = cpu_to_le16(smb_buffer->Command);
59 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
60 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
61 /* when mid allocated can be before when sent */
62 temp->when_alloc = jiffies;
63 temp->server = server;
66 * The default is for the mid to be synchronous, so the
67 * default callback just wakes up the current task.
69 get_task_struct(current);
70 temp->creator = current;
71 temp->callback = cifs_wake_up_task;
72 temp->callback_data = current;
74 atomic_inc(&mid_count);
75 temp->mid_state = MID_REQUEST_ALLOCATED;
79 void __release_mid(struct kref *refcount)
81 struct mid_q_entry *midEntry =
82 container_of(refcount, struct mid_q_entry, refcount);
83 #ifdef CONFIG_CIFS_STATS2
84 __le16 command = midEntry->server->vals->lock_cmd;
85 __u16 smb_cmd = le16_to_cpu(midEntry->command);
87 unsigned long roundtrip_time;
89 struct TCP_Server_Info *server = midEntry->server;
91 if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
92 (midEntry->mid_state == MID_RESPONSE_RECEIVED ||
93 midEntry->mid_state == MID_RESPONSE_READY) &&
94 server->ops->handle_cancelled_mid)
95 server->ops->handle_cancelled_mid(midEntry, server);
97 midEntry->mid_state = MID_FREE;
98 atomic_dec(&mid_count);
99 if (midEntry->large_buf)
100 cifs_buf_release(midEntry->resp_buf);
102 cifs_small_buf_release(midEntry->resp_buf);
103 #ifdef CONFIG_CIFS_STATS2
105 if (now < midEntry->when_alloc)
106 cifs_server_dbg(VFS, "Invalid mid allocation time\n");
107 roundtrip_time = now - midEntry->when_alloc;
109 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
110 if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
111 server->slowest_cmd[smb_cmd] = roundtrip_time;
112 server->fastest_cmd[smb_cmd] = roundtrip_time;
114 if (server->slowest_cmd[smb_cmd] < roundtrip_time)
115 server->slowest_cmd[smb_cmd] = roundtrip_time;
116 else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
117 server->fastest_cmd[smb_cmd] = roundtrip_time;
119 cifs_stats_inc(&server->num_cmds[smb_cmd]);
120 server->time_per_cmd[smb_cmd] += roundtrip_time;
123 * commands taking longer than one second (default) can be indications
124 * that something is wrong, unless it is quite a slow link or a very
125 * busy server. Note that this calc is unlikely or impossible to wrap
126 * as long as slow_rsp_threshold is not set way above recommended max
127 * value (32767 ie 9 hours) and is generally harmless even if wrong
128 * since only affects debug counters - so leaving the calc as simple
129 * comparison rather than doing multiple conversions and overflow
132 if ((slow_rsp_threshold != 0) &&
133 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
134 (midEntry->command != command)) {
136 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
137 * NB: le16_to_cpu returns unsigned so can not be negative below
139 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
140 cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
142 trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
143 midEntry->when_sent, midEntry->when_received);
144 if (cifsFYI & CIFS_TIMER) {
145 pr_debug("slow rsp: cmd %d mid %llu",
146 midEntry->command, midEntry->mid);
147 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
148 now - midEntry->when_alloc,
149 now - midEntry->when_sent,
150 now - midEntry->when_received);
154 put_task_struct(midEntry->creator);
156 mempool_free(midEntry, cifs_mid_poolp);
160 delete_mid(struct mid_q_entry *mid)
162 spin_lock(&mid->server->mid_lock);
163 if (!(mid->mid_flags & MID_DELETED)) {
164 list_del_init(&mid->qhead);
165 mid->mid_flags |= MID_DELETED;
167 spin_unlock(&mid->server->mid_lock);
173 * smb_send_kvec - send an array of kvecs to the server
174 * @server: Server to send the data to
175 * @smb_msg: Message to send
176 * @sent: amount of data sent on socket is stored here
178 * Our basic "send data to server" function. Should be called with srv_mutex
179 * held. The caller is responsible for handling the results.
182 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
187 struct socket *ssocket = server->ssocket;
191 if (server->noblocksnd)
192 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
194 smb_msg->msg_flags = MSG_NOSIGNAL;
196 while (msg_data_left(smb_msg)) {
198 * If blocking send, we try 3 times, since each can block
199 * for 5 seconds. For nonblocking we have to try more
200 * but wait increasing amounts of time allowing time for
201 * socket to clear. The overall time we wait in either
202 * case to send on the socket is about 15 seconds.
203 * Similarly we wait for 15 seconds for a response from
204 * the server in SendReceive[2] for the server to send
205 * a response back for most types of requests (except
206 * SMB Write past end of file which can be slow, and
207 * blocking lock operations). NFS waits slightly longer
208 * than CIFS, but this can make it take longer for
209 * nonresponsive servers to be detected and 15 seconds
210 * is more than enough time for modern networks to
211 * send a packet. In most cases if we fail to send
212 * after the retries we will kill the socket and
213 * reconnect which may clear the network problem.
215 rc = sock_sendmsg(ssocket, smb_msg);
219 (!server->noblocksnd && (retries > 2))) {
220 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
224 msleep(1 << retries);
232 /* should never happen, letting socket clear before
233 retrying is our only obvious option here */
234 cifs_server_dbg(VFS, "tcp sent no data\n");
239 /* send was at least partially successful */
241 retries = 0; /* in case we get ENOSPC on the next send */
247 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
252 unsigned long buflen = 0;
254 if (!is_smb1(server) && rqst->rq_nvec >= 2 &&
255 rqst->rq_iov[0].iov_len == 4) {
256 iov = &rqst->rq_iov[1];
257 nvec = rqst->rq_nvec - 1;
260 nvec = rqst->rq_nvec;
263 /* total up iov array first */
264 for (i = 0; i < nvec; i++)
265 buflen += iov[i].iov_len;
268 * Add in the page array if there is one. The caller needs to make
269 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
270 * multiple pages ends at page boundary, rq_tailsz needs to be set to
273 if (rqst->rq_npages) {
274 if (rqst->rq_npages == 1)
275 buflen += rqst->rq_tailsz;
278 * If there is more than one page, calculate the
279 * buffer length based on rq_offset and rq_tailsz
281 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
283 buflen += rqst->rq_tailsz;
291 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
292 struct smb_rqst *rqst)
297 unsigned int send_length = 0;
299 sigset_t mask, oldmask;
300 size_t total_len = 0, sent, size;
301 struct socket *ssocket = server->ssocket;
302 struct msghdr smb_msg = {};
303 __be32 rfc1002_marker;
305 cifs_in_send_inc(server);
306 if (cifs_rdma_enabled(server)) {
307 /* return -EAGAIN when connecting or reconnecting */
309 if (server->smbd_conn)
310 rc = smbd_send(server, num_rqst, rqst);
319 if (fatal_signal_pending(current)) {
320 cifs_dbg(FYI, "signal pending before send request\n");
325 /* cork the socket */
326 tcp_sock_set_cork(ssocket->sk, true);
328 for (j = 0; j < num_rqst; j++)
329 send_length += smb_rqst_len(server, &rqst[j]);
330 rfc1002_marker = cpu_to_be32(send_length);
333 * We should not allow signals to interrupt the network send because
334 * any partial send will cause session reconnects thus increasing
335 * latency of system calls and overload a server with unnecessary
340 sigprocmask(SIG_BLOCK, &mask, &oldmask);
342 /* Generate a rfc1002 marker for SMB2+ */
343 if (!is_smb1(server)) {
345 .iov_base = &rfc1002_marker,
348 iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, &hiov, 1, 4);
349 rc = smb_send_kvec(server, &smb_msg, &sent);
357 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
359 for (j = 0; j < num_rqst; j++) {
360 iov = rqst[j].rq_iov;
361 n_vec = rqst[j].rq_nvec;
364 for (i = 0; i < n_vec; i++) {
365 dump_smb(iov[i].iov_base, iov[i].iov_len);
366 size += iov[i].iov_len;
369 iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, iov, n_vec, size);
371 rc = smb_send_kvec(server, &smb_msg, &sent);
377 /* now walk the page array and send each page in it */
378 for (i = 0; i < rqst[j].rq_npages; i++) {
381 bvec.bv_page = rqst[j].rq_pages[i];
382 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
385 iov_iter_bvec(&smb_msg.msg_iter, ITER_SOURCE,
386 &bvec, 1, bvec.bv_len);
387 rc = smb_send_kvec(server, &smb_msg, &sent);
396 sigprocmask(SIG_SETMASK, &oldmask, NULL);
399 * If signal is pending but we have already sent the whole packet to
400 * the server we need to return success status to allow a corresponding
401 * mid entry to be kept in the pending requests queue thus allowing
402 * to handle responses from the server by the client.
404 * If only part of the packet has been sent there is no need to hide
405 * interrupt because the session will be reconnected anyway, so there
406 * won't be any response from the server to handle.
409 if (signal_pending(current) && (total_len != send_length)) {
410 cifs_dbg(FYI, "signal is pending after attempt to send\n");
415 tcp_sock_set_cork(ssocket->sk, false);
417 if ((total_len > 0) && (total_len != send_length)) {
418 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
419 send_length, total_len);
421 * If we have only sent part of an SMB then the next SMB could
422 * be taken as the remainder of this one. We need to kill the
423 * socket so the server throws away the partial SMB
425 cifs_signal_cifsd_for_reconnect(server, false);
426 trace_smb3_partial_send_reconnect(server->CurrentMid,
427 server->conn_id, server->hostname);
431 * there's hardly any use for the layers above to know the
432 * actual error code here. All they should do at this point is
433 * to retry the connection and hope it goes away.
435 if (rc < 0 && rc != -EINTR && rc != -EAGAIN) {
436 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
439 cifs_signal_cifsd_for_reconnect(server, false);
443 cifs_in_send_dec(server);
448 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
449 struct smb_rqst *rqst, int flags)
452 struct smb2_transform_hdr *tr_hdr;
453 struct smb_rqst cur_rqst[MAX_COMPOUND];
456 if (!(flags & CIFS_TRANSFORM_REQ))
457 return __smb_send_rqst(server, num_rqst, rqst);
459 if (WARN_ON_ONCE(num_rqst > MAX_COMPOUND - 1))
462 if (!server->ops->init_transform_rq) {
463 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
467 tr_hdr = kzalloc(sizeof(*tr_hdr), GFP_NOFS);
471 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
472 memset(&iov, 0, sizeof(iov));
474 iov.iov_base = tr_hdr;
475 iov.iov_len = sizeof(*tr_hdr);
476 cur_rqst[0].rq_iov = &iov;
477 cur_rqst[0].rq_nvec = 1;
479 rc = server->ops->init_transform_rq(server, num_rqst + 1,
484 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
485 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
492 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
493 unsigned int smb_buf_length)
496 struct smb_rqst rqst = { .rq_iov = iov,
499 iov[0].iov_base = smb_buffer;
501 iov[1].iov_base = (char *)smb_buffer + 4;
502 iov[1].iov_len = smb_buf_length;
504 return __smb_send_rqst(server, 1, &rqst);
508 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
509 const int timeout, const int flags,
510 unsigned int *instance)
516 int scredits, in_flight;
519 t = MAX_JIFFY_OFFSET;
521 t = msecs_to_jiffies(timeout);
523 optype = flags & CIFS_OP_MASK;
527 credits = server->ops->get_credits_field(server, optype);
528 /* Since an echo is already inflight, no need to wait to send another */
529 if (*credits <= 0 && optype == CIFS_ECHO_OP)
532 spin_lock(&server->req_lock);
533 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
534 /* oplock breaks must not be held up */
536 if (server->in_flight > server->max_in_flight)
537 server->max_in_flight = server->in_flight;
539 *instance = server->reconnect_instance;
541 in_flight = server->in_flight;
542 spin_unlock(&server->req_lock);
544 trace_smb3_nblk_credits(server->CurrentMid,
545 server->conn_id, server->hostname, scredits, -1, in_flight);
546 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
547 __func__, 1, scredits);
553 spin_unlock(&server->req_lock);
555 spin_lock(&server->srv_lock);
556 if (server->tcpStatus == CifsExiting) {
557 spin_unlock(&server->srv_lock);
560 spin_unlock(&server->srv_lock);
562 spin_lock(&server->req_lock);
563 if (*credits < num_credits) {
565 spin_unlock(&server->req_lock);
567 cifs_num_waiters_inc(server);
568 rc = wait_event_killable_timeout(server->request_q,
569 has_credits(server, credits, num_credits), t);
570 cifs_num_waiters_dec(server);
572 spin_lock(&server->req_lock);
574 in_flight = server->in_flight;
575 spin_unlock(&server->req_lock);
577 trace_smb3_credit_timeout(server->CurrentMid,
578 server->conn_id, server->hostname, scredits,
579 num_credits, in_flight);
580 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
584 if (rc == -ERESTARTSYS)
586 spin_lock(&server->req_lock);
589 * For normal commands, reserve the last MAX_COMPOUND
590 * credits to compound requests.
591 * Otherwise these compounds could be permanently
592 * starved for credits by single-credit requests.
594 * To prevent spinning CPU, block this thread until
595 * there are >MAX_COMPOUND credits available.
596 * But only do this is we already have a lot of
597 * credits in flight to avoid triggering this check
598 * for servers that are slow to hand out credits on
601 if (!optype && num_credits == 1 &&
602 server->in_flight > 2 * MAX_COMPOUND &&
603 *credits <= MAX_COMPOUND) {
604 spin_unlock(&server->req_lock);
606 cifs_num_waiters_inc(server);
607 rc = wait_event_killable_timeout(
609 has_credits(server, credits,
612 cifs_num_waiters_dec(server);
614 spin_lock(&server->req_lock);
616 in_flight = server->in_flight;
617 spin_unlock(&server->req_lock);
619 trace_smb3_credit_timeout(
621 server->conn_id, server->hostname,
622 scredits, num_credits, in_flight);
623 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
627 if (rc == -ERESTARTSYS)
629 spin_lock(&server->req_lock);
634 * Can not count locking commands against total
635 * as they are allowed to block on server.
638 /* update # of requests on the wire to server */
639 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
640 *credits -= num_credits;
641 server->in_flight += num_credits;
642 if (server->in_flight > server->max_in_flight)
643 server->max_in_flight = server->in_flight;
644 *instance = server->reconnect_instance;
647 in_flight = server->in_flight;
648 spin_unlock(&server->req_lock);
650 trace_smb3_waitff_credits(server->CurrentMid,
651 server->conn_id, server->hostname, scredits,
652 -(num_credits), in_flight);
653 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
654 __func__, num_credits, scredits);
662 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
663 unsigned int *instance)
665 return wait_for_free_credits(server, 1, -1, flags,
670 wait_for_compound_request(struct TCP_Server_Info *server, int num,
671 const int flags, unsigned int *instance)
674 int scredits, in_flight;
676 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
678 spin_lock(&server->req_lock);
680 in_flight = server->in_flight;
682 if (*credits < num) {
684 * If the server is tight on resources or just gives us less
685 * credits for other reasons (e.g. requests are coming out of
686 * order and the server delays granting more credits until it
687 * processes a missing mid) and we exhausted most available
688 * credits there may be situations when we try to send
689 * a compound request but we don't have enough credits. At this
690 * point the client needs to decide if it should wait for
691 * additional credits or fail the request. If at least one
692 * request is in flight there is a high probability that the
693 * server will return enough credits to satisfy this compound
696 * Return immediately if no requests in flight since we will be
697 * stuck on waiting for credits.
699 if (server->in_flight == 0) {
700 spin_unlock(&server->req_lock);
701 trace_smb3_insufficient_credits(server->CurrentMid,
702 server->conn_id, server->hostname, scredits,
704 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
705 __func__, in_flight, num, scredits);
709 spin_unlock(&server->req_lock);
711 return wait_for_free_credits(server, num, 60000, flags,
716 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
717 unsigned int *num, struct cifs_credits *credits)
721 credits->instance = server->reconnect_instance;
725 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
726 struct mid_q_entry **ppmidQ)
728 spin_lock(&ses->ses_lock);
729 if (ses->ses_status == SES_NEW) {
730 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
731 (in_buf->Command != SMB_COM_NEGOTIATE)) {
732 spin_unlock(&ses->ses_lock);
735 /* else ok - we are setting up session */
738 if (ses->ses_status == SES_EXITING) {
739 /* check if SMB session is bad because we are setting it up */
740 if (in_buf->Command != SMB_COM_LOGOFF_ANDX) {
741 spin_unlock(&ses->ses_lock);
744 /* else ok - we are shutting down session */
746 spin_unlock(&ses->ses_lock);
748 *ppmidQ = alloc_mid(in_buf, ses->server);
751 spin_lock(&ses->server->mid_lock);
752 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
753 spin_unlock(&ses->server->mid_lock);
758 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
762 error = wait_event_state(server->response_q,
763 midQ->mid_state != MID_REQUEST_SUBMITTED &&
764 midQ->mid_state != MID_RESPONSE_RECEIVED,
765 (TASK_KILLABLE|TASK_FREEZABLE_UNSAFE));
773 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
776 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
777 struct mid_q_entry *mid;
779 if (rqst->rq_iov[0].iov_len != 4 ||
780 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
781 return ERR_PTR(-EIO);
783 /* enable signing if server requires it */
785 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
787 mid = alloc_mid(hdr, server);
789 return ERR_PTR(-ENOMEM);
791 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
801 * Send a SMB request and set the callback function in the mid to handle
802 * the result. Caller is responsible for dealing with timeouts.
805 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
806 mid_receive_t *receive, mid_callback_t *callback,
807 mid_handle_t *handle, void *cbdata, const int flags,
808 const struct cifs_credits *exist_credits)
811 struct mid_q_entry *mid;
812 struct cifs_credits credits = { .value = 0, .instance = 0 };
813 unsigned int instance;
816 optype = flags & CIFS_OP_MASK;
818 if ((flags & CIFS_HAS_CREDITS) == 0) {
819 rc = wait_for_free_request(server, flags, &instance);
823 credits.instance = instance;
825 instance = exist_credits->instance;
827 cifs_server_lock(server);
830 * We can't use credits obtained from the previous session to send this
831 * request. Check if there were reconnects after we obtained credits and
832 * return -EAGAIN in such cases to let callers handle it.
834 if (instance != server->reconnect_instance) {
835 cifs_server_unlock(server);
836 add_credits_and_wake_if(server, &credits, optype);
840 mid = server->ops->setup_async_request(server, rqst);
842 cifs_server_unlock(server);
843 add_credits_and_wake_if(server, &credits, optype);
847 mid->receive = receive;
848 mid->callback = callback;
849 mid->callback_data = cbdata;
850 mid->handle = handle;
851 mid->mid_state = MID_REQUEST_SUBMITTED;
853 /* put it on the pending_mid_q */
854 spin_lock(&server->mid_lock);
855 list_add_tail(&mid->qhead, &server->pending_mid_q);
856 spin_unlock(&server->mid_lock);
859 * Need to store the time in mid before calling I/O. For call_async,
860 * I/O response may come back and free the mid entry on another thread.
862 cifs_save_when_sent(mid);
863 rc = smb_send_rqst(server, 1, rqst, flags);
866 revert_current_mid(server, mid->credits);
867 server->sequence_number -= 2;
871 cifs_server_unlock(server);
876 add_credits_and_wake_if(server, &credits, optype);
882 * Send an SMB Request. No response info (other than return code)
883 * needs to be parsed.
885 * flags indicate the type of request buffer and how long to wait
886 * and whether to log NT STATUS code (error) before mapping it to POSIX error
890 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
891 char *in_buf, int flags)
898 iov[0].iov_base = in_buf;
899 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
900 flags |= CIFS_NO_RSP_BUF;
901 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
902 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
908 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
912 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
913 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
915 spin_lock(&server->mid_lock);
916 switch (mid->mid_state) {
917 case MID_RESPONSE_READY:
918 spin_unlock(&server->mid_lock);
920 case MID_RETRY_NEEDED:
923 case MID_RESPONSE_MALFORMED:
930 if (!(mid->mid_flags & MID_DELETED)) {
931 list_del_init(&mid->qhead);
932 mid->mid_flags |= MID_DELETED;
934 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
935 __func__, mid->mid, mid->mid_state);
938 spin_unlock(&server->mid_lock);
945 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
946 struct mid_q_entry *mid)
948 return server->ops->send_cancel ?
949 server->ops->send_cancel(server, rqst, mid) : 0;
953 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
956 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
958 dump_smb(mid->resp_buf, min_t(u32, 92, len));
960 /* convert the length into a more usable form */
964 struct smb_rqst rqst = { .rq_iov = iov,
967 iov[0].iov_base = mid->resp_buf;
969 iov[1].iov_base = (char *)mid->resp_buf + 4;
970 iov[1].iov_len = len - 4;
971 /* FIXME: add code to kill session */
972 rc = cifs_verify_signature(&rqst, server,
973 mid->sequence_number);
975 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
979 /* BB special case reconnect tid and uid here? */
980 return map_and_check_smb_error(mid, log_error);
984 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
985 struct smb_rqst *rqst)
988 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
989 struct mid_q_entry *mid;
991 if (rqst->rq_iov[0].iov_len != 4 ||
992 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
993 return ERR_PTR(-EIO);
995 rc = allocate_mid(ses, hdr, &mid);
998 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
1007 cifs_compound_callback(struct mid_q_entry *mid)
1009 struct TCP_Server_Info *server = mid->server;
1010 struct cifs_credits credits;
1012 credits.value = server->ops->get_credits(mid);
1013 credits.instance = server->reconnect_instance;
1015 add_credits(server, &credits, mid->optype);
1017 if (mid->mid_state == MID_RESPONSE_RECEIVED)
1018 mid->mid_state = MID_RESPONSE_READY;
1022 cifs_compound_last_callback(struct mid_q_entry *mid)
1024 cifs_compound_callback(mid);
1025 cifs_wake_up_task(mid);
1029 cifs_cancelled_callback(struct mid_q_entry *mid)
1031 cifs_compound_callback(mid);
1036 * Return a channel (master if none) of @ses that can be used to send
1039 * If we are currently binding a new channel (negprot/sess.setup),
1040 * return the new incomplete channel.
1042 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1050 index = (uint)atomic_inc_return(&ses->chan_seq);
1052 spin_lock(&ses->chan_lock);
1053 index %= ses->chan_count;
1054 spin_unlock(&ses->chan_lock);
1056 return ses->chans[index].server;
1060 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1061 struct TCP_Server_Info *server,
1062 const int flags, const int num_rqst, struct smb_rqst *rqst,
1063 int *resp_buf_type, struct kvec *resp_iov)
1065 int i, j, optype, rc = 0;
1066 struct mid_q_entry *midQ[MAX_COMPOUND];
1067 bool cancelled_mid[MAX_COMPOUND] = {false};
1068 struct cifs_credits credits[MAX_COMPOUND] = {
1069 { .value = 0, .instance = 0 }
1071 unsigned int instance;
1074 optype = flags & CIFS_OP_MASK;
1076 for (i = 0; i < num_rqst; i++)
1077 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1079 if (!ses || !ses->server || !server) {
1080 cifs_dbg(VFS, "Null session\n");
1084 spin_lock(&server->srv_lock);
1085 if (server->tcpStatus == CifsExiting) {
1086 spin_unlock(&server->srv_lock);
1089 spin_unlock(&server->srv_lock);
1092 * Wait for all the requests to become available.
1093 * This approach still leaves the possibility to be stuck waiting for
1094 * credits if the server doesn't grant credits to the outstanding
1095 * requests and if the client is completely idle, not generating any
1097 * This can be handled by the eventual session reconnect.
1099 rc = wait_for_compound_request(server, num_rqst, flags,
1104 for (i = 0; i < num_rqst; i++) {
1105 credits[i].value = 1;
1106 credits[i].instance = instance;
1110 * Make sure that we sign in the same order that we send on this socket
1111 * and avoid races inside tcp sendmsg code that could cause corruption
1115 cifs_server_lock(server);
1118 * All the parts of the compound chain belong obtained credits from the
1119 * same session. We can not use credits obtained from the previous
1120 * session to send this request. Check if there were reconnects after
1121 * we obtained credits and return -EAGAIN in such cases to let callers
1124 if (instance != server->reconnect_instance) {
1125 cifs_server_unlock(server);
1126 for (j = 0; j < num_rqst; j++)
1127 add_credits(server, &credits[j], optype);
1131 for (i = 0; i < num_rqst; i++) {
1132 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1133 if (IS_ERR(midQ[i])) {
1134 revert_current_mid(server, i);
1135 for (j = 0; j < i; j++)
1136 delete_mid(midQ[j]);
1137 cifs_server_unlock(server);
1139 /* Update # of requests on wire to server */
1140 for (j = 0; j < num_rqst; j++)
1141 add_credits(server, &credits[j], optype);
1142 return PTR_ERR(midQ[i]);
1145 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1146 midQ[i]->optype = optype;
1148 * Invoke callback for every part of the compound chain
1149 * to calculate credits properly. Wake up this thread only when
1150 * the last element is received.
1152 if (i < num_rqst - 1)
1153 midQ[i]->callback = cifs_compound_callback;
1155 midQ[i]->callback = cifs_compound_last_callback;
1157 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1159 for (i = 0; i < num_rqst; i++)
1160 cifs_save_when_sent(midQ[i]);
1163 revert_current_mid(server, num_rqst);
1164 server->sequence_number -= 2;
1167 cifs_server_unlock(server);
1170 * If sending failed for some reason or it is an oplock break that we
1171 * will not receive a response to - return credits back
1173 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1174 for (i = 0; i < num_rqst; i++)
1175 add_credits(server, &credits[i], optype);
1180 * At this point the request is passed to the network stack - we assume
1181 * that any credits taken from the server structure on the client have
1182 * been spent and we can't return them back. Once we receive responses
1183 * we will collect credits granted by the server in the mid callbacks
1184 * and add those credits to the server structure.
1188 * Compounding is never used during session establish.
1190 spin_lock(&ses->ses_lock);
1191 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1192 spin_unlock(&ses->ses_lock);
1194 cifs_server_lock(server);
1195 smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec);
1196 cifs_server_unlock(server);
1198 spin_lock(&ses->ses_lock);
1200 spin_unlock(&ses->ses_lock);
1202 for (i = 0; i < num_rqst; i++) {
1203 rc = wait_for_response(server, midQ[i]);
1208 for (; i < num_rqst; i++) {
1209 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1210 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1211 send_cancel(server, &rqst[i], midQ[i]);
1212 spin_lock(&server->mid_lock);
1213 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1214 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED ||
1215 midQ[i]->mid_state == MID_RESPONSE_RECEIVED) {
1216 midQ[i]->callback = cifs_cancelled_callback;
1217 cancelled_mid[i] = true;
1218 credits[i].value = 0;
1220 spin_unlock(&server->mid_lock);
1224 for (i = 0; i < num_rqst; i++) {
1228 rc = cifs_sync_mid_result(midQ[i], server);
1230 /* mark this mid as cancelled to not free it below */
1231 cancelled_mid[i] = true;
1235 if (!midQ[i]->resp_buf ||
1236 midQ[i]->mid_state != MID_RESPONSE_READY) {
1238 cifs_dbg(FYI, "Bad MID state?\n");
1242 buf = (char *)midQ[i]->resp_buf;
1243 resp_iov[i].iov_base = buf;
1244 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1245 HEADER_PREAMBLE_SIZE(server);
1247 if (midQ[i]->large_buf)
1248 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1250 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1252 rc = server->ops->check_receive(midQ[i], server,
1253 flags & CIFS_LOG_ERROR);
1255 /* mark it so buf will not be freed by delete_mid */
1256 if ((flags & CIFS_NO_RSP_BUF) == 0)
1257 midQ[i]->resp_buf = NULL;
1262 * Compounding is never used during session establish.
1264 spin_lock(&ses->ses_lock);
1265 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1267 .iov_base = resp_iov[0].iov_base,
1268 .iov_len = resp_iov[0].iov_len
1270 spin_unlock(&ses->ses_lock);
1271 cifs_server_lock(server);
1272 smb311_update_preauth_hash(ses, server, &iov, 1);
1273 cifs_server_unlock(server);
1274 spin_lock(&ses->ses_lock);
1276 spin_unlock(&ses->ses_lock);
1280 * This will dequeue all mids. After this it is important that the
1281 * demultiplex_thread will not process any of these mids any futher.
1282 * This is prevented above by using a noop callback that will not
1283 * wake this thread except for the very last PDU.
1285 for (i = 0; i < num_rqst; i++) {
1286 if (!cancelled_mid[i])
1287 delete_mid(midQ[i]);
1294 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1295 struct TCP_Server_Info *server,
1296 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1297 struct kvec *resp_iov)
1299 return compound_send_recv(xid, ses, server, flags, 1,
1300 rqst, resp_buf_type, resp_iov);
1304 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1305 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1306 const int flags, struct kvec *resp_iov)
1308 struct smb_rqst rqst;
1309 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1312 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1313 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1316 /* otherwise cifs_send_recv below sets resp_buf_type */
1317 *resp_buf_type = CIFS_NO_BUFFER;
1323 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1324 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1326 new_iov[0].iov_base = new_iov[1].iov_base;
1327 new_iov[0].iov_len = 4;
1328 new_iov[1].iov_base += 4;
1329 new_iov[1].iov_len -= 4;
1331 memset(&rqst, 0, sizeof(struct smb_rqst));
1332 rqst.rq_iov = new_iov;
1333 rqst.rq_nvec = n_vec + 1;
1335 rc = cifs_send_recv(xid, ses, ses->server,
1336 &rqst, resp_buf_type, flags, resp_iov);
1337 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1343 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1344 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1345 int *pbytes_returned, const int flags)
1348 struct mid_q_entry *midQ;
1349 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1350 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1351 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1352 struct cifs_credits credits = { .value = 1, .instance = 0 };
1353 struct TCP_Server_Info *server;
1356 cifs_dbg(VFS, "Null smb session\n");
1359 server = ses->server;
1360 if (server == NULL) {
1361 cifs_dbg(VFS, "Null tcp session\n");
1365 spin_lock(&server->srv_lock);
1366 if (server->tcpStatus == CifsExiting) {
1367 spin_unlock(&server->srv_lock);
1370 spin_unlock(&server->srv_lock);
1372 /* Ensure that we do not send more than 50 overlapping requests
1373 to the same server. We may make this configurable later or
1376 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1377 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1382 rc = wait_for_free_request(server, flags, &credits.instance);
1386 /* make sure that we sign in the same order that we send on this socket
1387 and avoid races inside tcp sendmsg code that could cause corruption
1390 cifs_server_lock(server);
1392 rc = allocate_mid(ses, in_buf, &midQ);
1394 cifs_server_unlock(server);
1395 /* Update # of requests on wire to server */
1396 add_credits(server, &credits, 0);
1400 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1402 cifs_server_unlock(server);
1406 midQ->mid_state = MID_REQUEST_SUBMITTED;
1408 rc = smb_send(server, in_buf, len);
1409 cifs_save_when_sent(midQ);
1412 server->sequence_number -= 2;
1414 cifs_server_unlock(server);
1419 rc = wait_for_response(server, midQ);
1421 send_cancel(server, &rqst, midQ);
1422 spin_lock(&server->mid_lock);
1423 if (midQ->mid_state == MID_REQUEST_SUBMITTED ||
1424 midQ->mid_state == MID_RESPONSE_RECEIVED) {
1425 /* no longer considered to be "in-flight" */
1426 midQ->callback = release_mid;
1427 spin_unlock(&server->mid_lock);
1428 add_credits(server, &credits, 0);
1431 spin_unlock(&server->mid_lock);
1434 rc = cifs_sync_mid_result(midQ, server);
1436 add_credits(server, &credits, 0);
1440 if (!midQ->resp_buf || !out_buf ||
1441 midQ->mid_state != MID_RESPONSE_READY) {
1443 cifs_server_dbg(VFS, "Bad MID state?\n");
1447 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1448 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1449 rc = cifs_check_receive(midQ, server, 0);
1452 add_credits(server, &credits, 0);
1457 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1458 blocking lock to return. */
1461 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1462 struct smb_hdr *in_buf,
1463 struct smb_hdr *out_buf)
1466 struct cifs_ses *ses = tcon->ses;
1467 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1469 /* We just modify the current in_buf to change
1470 the type of lock from LOCKING_ANDX_SHARED_LOCK
1471 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1472 LOCKING_ANDX_CANCEL_LOCK. */
1474 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1476 pSMB->hdr.Mid = get_next_mid(ses->server);
1478 return SendReceive(xid, ses, in_buf, out_buf,
1479 &bytes_returned, 0);
1483 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1484 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1485 int *pbytes_returned)
1489 struct mid_q_entry *midQ;
1490 struct cifs_ses *ses;
1491 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1492 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1493 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1494 unsigned int instance;
1495 struct TCP_Server_Info *server;
1497 if (tcon == NULL || tcon->ses == NULL) {
1498 cifs_dbg(VFS, "Null smb session\n");
1502 server = ses->server;
1504 if (server == NULL) {
1505 cifs_dbg(VFS, "Null tcp session\n");
1509 spin_lock(&server->srv_lock);
1510 if (server->tcpStatus == CifsExiting) {
1511 spin_unlock(&server->srv_lock);
1514 spin_unlock(&server->srv_lock);
1516 /* Ensure that we do not send more than 50 overlapping requests
1517 to the same server. We may make this configurable later or
1520 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1521 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1526 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1530 /* make sure that we sign in the same order that we send on this socket
1531 and avoid races inside tcp sendmsg code that could cause corruption
1534 cifs_server_lock(server);
1536 rc = allocate_mid(ses, in_buf, &midQ);
1538 cifs_server_unlock(server);
1542 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1545 cifs_server_unlock(server);
1549 midQ->mid_state = MID_REQUEST_SUBMITTED;
1550 rc = smb_send(server, in_buf, len);
1551 cifs_save_when_sent(midQ);
1554 server->sequence_number -= 2;
1556 cifs_server_unlock(server);
1563 /* Wait for a reply - allow signals to interrupt. */
1564 rc = wait_event_interruptible(server->response_q,
1565 (!(midQ->mid_state == MID_REQUEST_SUBMITTED ||
1566 midQ->mid_state == MID_RESPONSE_RECEIVED)) ||
1567 ((server->tcpStatus != CifsGood) &&
1568 (server->tcpStatus != CifsNew)));
1570 /* Were we interrupted by a signal ? */
1571 spin_lock(&server->srv_lock);
1572 if ((rc == -ERESTARTSYS) &&
1573 (midQ->mid_state == MID_REQUEST_SUBMITTED ||
1574 midQ->mid_state == MID_RESPONSE_RECEIVED) &&
1575 ((server->tcpStatus == CifsGood) ||
1576 (server->tcpStatus == CifsNew))) {
1577 spin_unlock(&server->srv_lock);
1579 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1580 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1581 blocking lock to return. */
1582 rc = send_cancel(server, &rqst, midQ);
1588 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1589 to cause the blocking lock to return. */
1591 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1593 /* If we get -ENOLCK back the lock may have
1594 already been removed. Don't exit in this case. */
1595 if (rc && rc != -ENOLCK) {
1601 rc = wait_for_response(server, midQ);
1603 send_cancel(server, &rqst, midQ);
1604 spin_lock(&server->mid_lock);
1605 if (midQ->mid_state == MID_REQUEST_SUBMITTED ||
1606 midQ->mid_state == MID_RESPONSE_RECEIVED) {
1607 /* no longer considered to be "in-flight" */
1608 midQ->callback = release_mid;
1609 spin_unlock(&server->mid_lock);
1612 spin_unlock(&server->mid_lock);
1615 /* We got the response - restart system call. */
1617 spin_lock(&server->srv_lock);
1619 spin_unlock(&server->srv_lock);
1621 rc = cifs_sync_mid_result(midQ, server);
1625 /* rcvd frame is ok */
1626 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_READY) {
1628 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1632 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1633 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1634 rc = cifs_check_receive(midQ, server, 0);
1637 if (rstart && rc == -EACCES)
1638 return -ERESTARTSYS;
1643 * Discard any remaining data in the current SMB. To do this, we borrow the
1647 cifs_discard_remaining_data(struct TCP_Server_Info *server)
1649 unsigned int rfclen = server->pdu_size;
1650 int remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
1653 while (remaining > 0) {
1656 length = cifs_discard_from_socket(server,
1657 min_t(size_t, remaining,
1658 CIFSMaxBufSize + MAX_HEADER_SIZE(server)));
1661 server->total_read += length;
1662 remaining -= length;
1669 __cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid,
1674 length = cifs_discard_remaining_data(server);
1675 dequeue_mid(mid, malformed);
1676 mid->resp_buf = server->smallbuf;
1677 server->smallbuf = NULL;
1682 cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1684 struct cifs_readdata *rdata = mid->callback_data;
1686 return __cifs_readv_discard(server, mid, rdata->result);
1690 cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1693 unsigned int data_offset, data_len;
1694 struct cifs_readdata *rdata = mid->callback_data;
1695 char *buf = server->smallbuf;
1696 unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server);
1697 bool use_rdma_mr = false;
1699 cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
1700 __func__, mid->mid, rdata->offset, rdata->bytes);
1703 * read the rest of READ_RSP header (sans Data array), or whatever we
1704 * can if there's not enough data. At this point, we've read down to
1707 len = min_t(unsigned int, buflen, server->vals->read_rsp_size) -
1708 HEADER_SIZE(server) + 1;
1710 length = cifs_read_from_socket(server,
1711 buf + HEADER_SIZE(server) - 1, len);
1714 server->total_read += length;
1716 if (server->ops->is_session_expired &&
1717 server->ops->is_session_expired(buf)) {
1718 cifs_reconnect(server, true);
1722 if (server->ops->is_status_pending &&
1723 server->ops->is_status_pending(buf, server)) {
1724 cifs_discard_remaining_data(server);
1728 /* set up first two iov for signature check and to get credits */
1729 rdata->iov[0].iov_base = buf;
1730 rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server);
1731 rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server);
1732 rdata->iov[1].iov_len =
1733 server->total_read - HEADER_PREAMBLE_SIZE(server);
1734 cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
1735 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
1736 cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
1737 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
1739 /* Was the SMB read successful? */
1740 rdata->result = server->ops->map_error(buf, false);
1741 if (rdata->result != 0) {
1742 cifs_dbg(FYI, "%s: server returned error %d\n",
1743 __func__, rdata->result);
1744 /* normal error on read response */
1745 return __cifs_readv_discard(server, mid, false);
1748 /* Is there enough to get to the rest of the READ_RSP header? */
1749 if (server->total_read < server->vals->read_rsp_size) {
1750 cifs_dbg(FYI, "%s: server returned short header. got=%u expected=%zu\n",
1751 __func__, server->total_read,
1752 server->vals->read_rsp_size);
1753 rdata->result = -EIO;
1754 return cifs_readv_discard(server, mid);
1757 data_offset = server->ops->read_data_offset(buf) +
1758 HEADER_PREAMBLE_SIZE(server);
1759 if (data_offset < server->total_read) {
1761 * win2k8 sometimes sends an offset of 0 when the read
1762 * is beyond the EOF. Treat it as if the data starts just after
1765 cifs_dbg(FYI, "%s: data offset (%u) inside read response header\n",
1766 __func__, data_offset);
1767 data_offset = server->total_read;
1768 } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) {
1769 /* data_offset is beyond the end of smallbuf */
1770 cifs_dbg(FYI, "%s: data offset (%u) beyond end of smallbuf\n",
1771 __func__, data_offset);
1772 rdata->result = -EIO;
1773 return cifs_readv_discard(server, mid);
1776 cifs_dbg(FYI, "%s: total_read=%u data_offset=%u\n",
1777 __func__, server->total_read, data_offset);
1779 len = data_offset - server->total_read;
1781 /* read any junk before data into the rest of smallbuf */
1782 length = cifs_read_from_socket(server,
1783 buf + server->total_read, len);
1786 server->total_read += length;
1789 /* how much data is in the response? */
1790 #ifdef CONFIG_CIFS_SMB_DIRECT
1791 use_rdma_mr = rdata->mr;
1793 data_len = server->ops->read_data_length(buf, use_rdma_mr);
1794 if (!use_rdma_mr && (data_offset + data_len > buflen)) {
1795 /* data_len is corrupt -- discard frame */
1796 rdata->result = -EIO;
1797 return cifs_readv_discard(server, mid);
1800 length = rdata->read_into_pages(server, rdata, data_len);
1804 server->total_read += length;
1806 cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n",
1807 server->total_read, buflen, data_len);
1809 /* discard anything left over */
1810 if (server->total_read < buflen)
1811 return cifs_readv_discard(server, mid);
1813 dequeue_mid(mid, false);
1814 mid->resp_buf = server->smallbuf;
1815 server->smallbuf = NULL;