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 wake_up_process(mid->callback_data);
41 static struct mid_q_entry *
42 alloc_mid(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
44 struct mid_q_entry *temp;
47 cifs_dbg(VFS, "%s: null TCP session\n", __func__);
51 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
52 memset(temp, 0, sizeof(struct mid_q_entry));
53 kref_init(&temp->refcount);
54 temp->mid = get_mid(smb_buffer);
55 temp->pid = current->pid;
56 temp->command = cpu_to_le16(smb_buffer->Command);
57 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
58 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
59 /* when mid allocated can be before when sent */
60 temp->when_alloc = jiffies;
61 temp->server = server;
64 * The default is for the mid to be synchronous, so the
65 * default callback just wakes up the current task.
67 get_task_struct(current);
68 temp->creator = current;
69 temp->callback = cifs_wake_up_task;
70 temp->callback_data = current;
72 atomic_inc(&mid_count);
73 temp->mid_state = MID_REQUEST_ALLOCATED;
77 static void __release_mid(struct kref *refcount)
79 struct mid_q_entry *midEntry =
80 container_of(refcount, struct mid_q_entry, refcount);
81 #ifdef CONFIG_CIFS_STATS2
82 __le16 command = midEntry->server->vals->lock_cmd;
83 __u16 smb_cmd = le16_to_cpu(midEntry->command);
85 unsigned long roundtrip_time;
87 struct TCP_Server_Info *server = midEntry->server;
89 if (midEntry->resp_buf && (midEntry->mid_flags & MID_WAIT_CANCELLED) &&
90 midEntry->mid_state == MID_RESPONSE_RECEIVED &&
91 server->ops->handle_cancelled_mid)
92 server->ops->handle_cancelled_mid(midEntry, server);
94 midEntry->mid_state = MID_FREE;
95 atomic_dec(&mid_count);
96 if (midEntry->large_buf)
97 cifs_buf_release(midEntry->resp_buf);
99 cifs_small_buf_release(midEntry->resp_buf);
100 #ifdef CONFIG_CIFS_STATS2
102 if (now < midEntry->when_alloc)
103 cifs_server_dbg(VFS, "Invalid mid allocation time\n");
104 roundtrip_time = now - midEntry->when_alloc;
106 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS) {
107 if (atomic_read(&server->num_cmds[smb_cmd]) == 0) {
108 server->slowest_cmd[smb_cmd] = roundtrip_time;
109 server->fastest_cmd[smb_cmd] = roundtrip_time;
111 if (server->slowest_cmd[smb_cmd] < roundtrip_time)
112 server->slowest_cmd[smb_cmd] = roundtrip_time;
113 else if (server->fastest_cmd[smb_cmd] > roundtrip_time)
114 server->fastest_cmd[smb_cmd] = roundtrip_time;
116 cifs_stats_inc(&server->num_cmds[smb_cmd]);
117 server->time_per_cmd[smb_cmd] += roundtrip_time;
120 * commands taking longer than one second (default) can be indications
121 * that something is wrong, unless it is quite a slow link or a very
122 * busy server. Note that this calc is unlikely or impossible to wrap
123 * as long as slow_rsp_threshold is not set way above recommended max
124 * value (32767 ie 9 hours) and is generally harmless even if wrong
125 * since only affects debug counters - so leaving the calc as simple
126 * comparison rather than doing multiple conversions and overflow
129 if ((slow_rsp_threshold != 0) &&
130 time_after(now, midEntry->when_alloc + (slow_rsp_threshold * HZ)) &&
131 (midEntry->command != command)) {
133 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
134 * NB: le16_to_cpu returns unsigned so can not be negative below
136 if (smb_cmd < NUMBER_OF_SMB2_COMMANDS)
137 cifs_stats_inc(&server->smb2slowcmd[smb_cmd]);
139 trace_smb3_slow_rsp(smb_cmd, midEntry->mid, midEntry->pid,
140 midEntry->when_sent, midEntry->when_received);
141 if (cifsFYI & CIFS_TIMER) {
142 pr_debug("slow rsp: cmd %d mid %llu",
143 midEntry->command, midEntry->mid);
144 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
145 now - midEntry->when_alloc,
146 now - midEntry->when_sent,
147 now - midEntry->when_received);
151 put_task_struct(midEntry->creator);
153 mempool_free(midEntry, cifs_mid_poolp);
156 void release_mid(struct mid_q_entry *mid)
158 struct TCP_Server_Info *server = mid->server;
160 spin_lock(&server->mid_lock);
161 kref_put(&mid->refcount, __release_mid);
162 spin_unlock(&server->mid_lock);
166 delete_mid(struct mid_q_entry *mid)
168 spin_lock(&mid->server->mid_lock);
169 if (!(mid->mid_flags & MID_DELETED)) {
170 list_del_init(&mid->qhead);
171 mid->mid_flags |= MID_DELETED;
173 spin_unlock(&mid->server->mid_lock);
179 * smb_send_kvec - send an array of kvecs to the server
180 * @server: Server to send the data to
181 * @smb_msg: Message to send
182 * @sent: amount of data sent on socket is stored here
184 * Our basic "send data to server" function. Should be called with srv_mutex
185 * held. The caller is responsible for handling the results.
188 smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
193 struct socket *ssocket = server->ssocket;
197 if (server->noblocksnd)
198 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
200 smb_msg->msg_flags = MSG_NOSIGNAL;
202 while (msg_data_left(smb_msg)) {
204 * If blocking send, we try 3 times, since each can block
205 * for 5 seconds. For nonblocking we have to try more
206 * but wait increasing amounts of time allowing time for
207 * socket to clear. The overall time we wait in either
208 * case to send on the socket is about 15 seconds.
209 * Similarly we wait for 15 seconds for a response from
210 * the server in SendReceive[2] for the server to send
211 * a response back for most types of requests (except
212 * SMB Write past end of file which can be slow, and
213 * blocking lock operations). NFS waits slightly longer
214 * than CIFS, but this can make it take longer for
215 * nonresponsive servers to be detected and 15 seconds
216 * is more than enough time for modern networks to
217 * send a packet. In most cases if we fail to send
218 * after the retries we will kill the socket and
219 * reconnect which may clear the network problem.
221 rc = sock_sendmsg(ssocket, smb_msg);
225 (!server->noblocksnd && (retries > 2))) {
226 cifs_server_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
230 msleep(1 << retries);
238 /* should never happen, letting socket clear before
239 retrying is our only obvious option here */
240 cifs_server_dbg(VFS, "tcp sent no data\n");
245 /* send was at least partially successful */
247 retries = 0; /* in case we get ENOSPC on the next send */
253 smb_rqst_len(struct TCP_Server_Info *server, struct smb_rqst *rqst)
258 unsigned long buflen = 0;
260 if (!is_smb1(server) && rqst->rq_nvec >= 2 &&
261 rqst->rq_iov[0].iov_len == 4) {
262 iov = &rqst->rq_iov[1];
263 nvec = rqst->rq_nvec - 1;
266 nvec = rqst->rq_nvec;
269 /* total up iov array first */
270 for (i = 0; i < nvec; i++)
271 buflen += iov[i].iov_len;
274 * Add in the page array if there is one. The caller needs to make
275 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
276 * multiple pages ends at page boundary, rq_tailsz needs to be set to
279 if (rqst->rq_npages) {
280 if (rqst->rq_npages == 1)
281 buflen += rqst->rq_tailsz;
284 * If there is more than one page, calculate the
285 * buffer length based on rq_offset and rq_tailsz
287 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1) -
289 buflen += rqst->rq_tailsz;
297 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
298 struct smb_rqst *rqst)
303 unsigned int send_length = 0;
305 sigset_t mask, oldmask;
306 size_t total_len = 0, sent, size;
307 struct socket *ssocket = server->ssocket;
308 struct msghdr smb_msg = {};
309 __be32 rfc1002_marker;
311 cifs_in_send_inc(server);
312 if (cifs_rdma_enabled(server)) {
313 /* return -EAGAIN when connecting or reconnecting */
315 if (server->smbd_conn)
316 rc = smbd_send(server, num_rqst, rqst);
325 if (fatal_signal_pending(current)) {
326 cifs_dbg(FYI, "signal pending before send request\n");
331 /* cork the socket */
332 tcp_sock_set_cork(ssocket->sk, true);
334 for (j = 0; j < num_rqst; j++)
335 send_length += smb_rqst_len(server, &rqst[j]);
336 rfc1002_marker = cpu_to_be32(send_length);
339 * We should not allow signals to interrupt the network send because
340 * any partial send will cause session reconnects thus increasing
341 * latency of system calls and overload a server with unnecessary
346 sigprocmask(SIG_BLOCK, &mask, &oldmask);
348 /* Generate a rfc1002 marker for SMB2+ */
349 if (!is_smb1(server)) {
351 .iov_base = &rfc1002_marker,
354 iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, &hiov, 1, 4);
355 rc = smb_send_kvec(server, &smb_msg, &sent);
363 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
365 for (j = 0; j < num_rqst; j++) {
366 iov = rqst[j].rq_iov;
367 n_vec = rqst[j].rq_nvec;
370 for (i = 0; i < n_vec; i++) {
371 dump_smb(iov[i].iov_base, iov[i].iov_len);
372 size += iov[i].iov_len;
375 iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, iov, n_vec, size);
377 rc = smb_send_kvec(server, &smb_msg, &sent);
383 /* now walk the page array and send each page in it */
384 for (i = 0; i < rqst[j].rq_npages; i++) {
387 bvec.bv_page = rqst[j].rq_pages[i];
388 rqst_page_get_length(&rqst[j], i, &bvec.bv_len,
391 iov_iter_bvec(&smb_msg.msg_iter, ITER_SOURCE,
392 &bvec, 1, bvec.bv_len);
393 rc = smb_send_kvec(server, &smb_msg, &sent);
402 sigprocmask(SIG_SETMASK, &oldmask, NULL);
405 * If signal is pending but we have already sent the whole packet to
406 * the server we need to return success status to allow a corresponding
407 * mid entry to be kept in the pending requests queue thus allowing
408 * to handle responses from the server by the client.
410 * If only part of the packet has been sent there is no need to hide
411 * interrupt because the session will be reconnected anyway, so there
412 * won't be any response from the server to handle.
415 if (signal_pending(current) && (total_len != send_length)) {
416 cifs_dbg(FYI, "signal is pending after attempt to send\n");
421 tcp_sock_set_cork(ssocket->sk, false);
423 if ((total_len > 0) && (total_len != send_length)) {
424 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
425 send_length, total_len);
427 * If we have only sent part of an SMB then the next SMB could
428 * be taken as the remainder of this one. We need to kill the
429 * socket so the server throws away the partial SMB
431 cifs_signal_cifsd_for_reconnect(server, false);
432 trace_smb3_partial_send_reconnect(server->CurrentMid,
433 server->conn_id, server->hostname);
436 if (rc < 0 && rc != -EINTR)
437 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
442 cifs_in_send_dec(server);
447 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
448 struct smb_rqst *rqst, int flags)
451 struct smb2_transform_hdr *tr_hdr;
452 struct smb_rqst cur_rqst[MAX_COMPOUND];
455 if (!(flags & CIFS_TRANSFORM_REQ))
456 return __smb_send_rqst(server, num_rqst, rqst);
458 if (num_rqst > MAX_COMPOUND - 1)
461 if (!server->ops->init_transform_rq) {
462 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
466 tr_hdr = kzalloc(sizeof(*tr_hdr), GFP_NOFS);
470 memset(&cur_rqst[0], 0, sizeof(cur_rqst));
471 memset(&iov, 0, sizeof(iov));
473 iov.iov_base = tr_hdr;
474 iov.iov_len = sizeof(*tr_hdr);
475 cur_rqst[0].rq_iov = &iov;
476 cur_rqst[0].rq_nvec = 1;
478 rc = server->ops->init_transform_rq(server, num_rqst + 1,
483 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
484 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
491 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
492 unsigned int smb_buf_length)
495 struct smb_rqst rqst = { .rq_iov = iov,
498 iov[0].iov_base = smb_buffer;
500 iov[1].iov_base = (char *)smb_buffer + 4;
501 iov[1].iov_len = smb_buf_length;
503 return __smb_send_rqst(server, 1, &rqst);
507 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
508 const int timeout, const int flags,
509 unsigned int *instance)
515 int scredits, in_flight;
518 t = MAX_JIFFY_OFFSET;
520 t = msecs_to_jiffies(timeout);
522 optype = flags & CIFS_OP_MASK;
526 credits = server->ops->get_credits_field(server, optype);
527 /* Since an echo is already inflight, no need to wait to send another */
528 if (*credits <= 0 && optype == CIFS_ECHO_OP)
531 spin_lock(&server->req_lock);
532 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
533 /* oplock breaks must not be held up */
535 if (server->in_flight > server->max_in_flight)
536 server->max_in_flight = server->in_flight;
538 *instance = server->reconnect_instance;
540 in_flight = server->in_flight;
541 spin_unlock(&server->req_lock);
543 trace_smb3_nblk_credits(server->CurrentMid,
544 server->conn_id, server->hostname, scredits, -1, in_flight);
545 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
546 __func__, 1, scredits);
552 if (*credits < num_credits) {
554 spin_unlock(&server->req_lock);
556 cifs_num_waiters_inc(server);
557 rc = wait_event_killable_timeout(server->request_q,
558 has_credits(server, credits, num_credits), t);
559 cifs_num_waiters_dec(server);
561 spin_lock(&server->req_lock);
563 in_flight = server->in_flight;
564 spin_unlock(&server->req_lock);
566 trace_smb3_credit_timeout(server->CurrentMid,
567 server->conn_id, server->hostname, scredits,
568 num_credits, in_flight);
569 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
573 if (rc == -ERESTARTSYS)
575 spin_lock(&server->req_lock);
577 spin_unlock(&server->req_lock);
579 spin_lock(&server->srv_lock);
580 if (server->tcpStatus == CifsExiting) {
581 spin_unlock(&server->srv_lock);
584 spin_unlock(&server->srv_lock);
587 * For normal commands, reserve the last MAX_COMPOUND
588 * credits to compound requests.
589 * Otherwise these compounds could be permanently
590 * starved for credits by single-credit requests.
592 * To prevent spinning CPU, block this thread until
593 * there are >MAX_COMPOUND credits available.
594 * But only do this is we already have a lot of
595 * credits in flight to avoid triggering this check
596 * for servers that are slow to hand out credits on
599 spin_lock(&server->req_lock);
600 if (!optype && num_credits == 1 &&
601 server->in_flight > 2 * MAX_COMPOUND &&
602 *credits <= MAX_COMPOUND) {
603 spin_unlock(&server->req_lock);
605 cifs_num_waiters_inc(server);
606 rc = wait_event_killable_timeout(
608 has_credits(server, credits,
611 cifs_num_waiters_dec(server);
613 spin_lock(&server->req_lock);
615 in_flight = server->in_flight;
616 spin_unlock(&server->req_lock);
618 trace_smb3_credit_timeout(
620 server->conn_id, server->hostname,
621 scredits, num_credits, in_flight);
622 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
626 if (rc == -ERESTARTSYS)
628 spin_lock(&server->req_lock);
633 * Can not count locking commands against total
634 * as they are allowed to block on server.
637 /* update # of requests on the wire to server */
638 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
639 *credits -= num_credits;
640 server->in_flight += num_credits;
641 if (server->in_flight > server->max_in_flight)
642 server->max_in_flight = server->in_flight;
643 *instance = server->reconnect_instance;
646 in_flight = server->in_flight;
647 spin_unlock(&server->req_lock);
649 trace_smb3_waitff_credits(server->CurrentMid,
650 server->conn_id, server->hostname, scredits,
651 -(num_credits), in_flight);
652 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
653 __func__, num_credits, scredits);
661 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
662 unsigned int *instance)
664 return wait_for_free_credits(server, 1, -1, flags,
669 wait_for_compound_request(struct TCP_Server_Info *server, int num,
670 const int flags, unsigned int *instance)
673 int scredits, in_flight;
675 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
677 spin_lock(&server->req_lock);
679 in_flight = server->in_flight;
681 if (*credits < num) {
683 * If the server is tight on resources or just gives us less
684 * credits for other reasons (e.g. requests are coming out of
685 * order and the server delays granting more credits until it
686 * processes a missing mid) and we exhausted most available
687 * credits there may be situations when we try to send
688 * a compound request but we don't have enough credits. At this
689 * point the client needs to decide if it should wait for
690 * additional credits or fail the request. If at least one
691 * request is in flight there is a high probability that the
692 * server will return enough credits to satisfy this compound
695 * Return immediately if no requests in flight since we will be
696 * stuck on waiting for credits.
698 if (server->in_flight == 0) {
699 spin_unlock(&server->req_lock);
700 trace_smb3_insufficient_credits(server->CurrentMid,
701 server->conn_id, server->hostname, scredits,
703 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
704 __func__, in_flight, num, scredits);
708 spin_unlock(&server->req_lock);
710 return wait_for_free_credits(server, num, 60000, flags,
715 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
716 unsigned int *num, struct cifs_credits *credits)
720 credits->instance = server->reconnect_instance;
724 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
725 struct mid_q_entry **ppmidQ)
727 spin_lock(&ses->ses_lock);
728 if (ses->ses_status == SES_NEW) {
729 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
730 (in_buf->Command != SMB_COM_NEGOTIATE)) {
731 spin_unlock(&ses->ses_lock);
734 /* else ok - we are setting up session */
737 if (ses->ses_status == SES_EXITING) {
738 /* check if SMB session is bad because we are setting it up */
739 if (in_buf->Command != SMB_COM_LOGOFF_ANDX) {
740 spin_unlock(&ses->ses_lock);
743 /* else ok - we are shutting down session */
745 spin_unlock(&ses->ses_lock);
747 *ppmidQ = alloc_mid(in_buf, ses->server);
750 spin_lock(&ses->server->mid_lock);
751 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
752 spin_unlock(&ses->server->mid_lock);
757 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
761 error = wait_event_state(server->response_q,
762 midQ->mid_state != MID_REQUEST_SUBMITTED,
763 (TASK_KILLABLE|TASK_FREEZABLE_UNSAFE));
771 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
774 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
775 struct mid_q_entry *mid;
777 if (rqst->rq_iov[0].iov_len != 4 ||
778 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
779 return ERR_PTR(-EIO);
781 /* enable signing if server requires it */
783 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
785 mid = alloc_mid(hdr, server);
787 return ERR_PTR(-ENOMEM);
789 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
799 * Send a SMB request and set the callback function in the mid to handle
800 * the result. Caller is responsible for dealing with timeouts.
803 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
804 mid_receive_t *receive, mid_callback_t *callback,
805 mid_handle_t *handle, void *cbdata, const int flags,
806 const struct cifs_credits *exist_credits)
809 struct mid_q_entry *mid;
810 struct cifs_credits credits = { .value = 0, .instance = 0 };
811 unsigned int instance;
814 optype = flags & CIFS_OP_MASK;
816 if ((flags & CIFS_HAS_CREDITS) == 0) {
817 rc = wait_for_free_request(server, flags, &instance);
821 credits.instance = instance;
823 instance = exist_credits->instance;
825 cifs_server_lock(server);
828 * We can't use credits obtained from the previous session to send this
829 * request. Check if there were reconnects after we obtained credits and
830 * return -EAGAIN in such cases to let callers handle it.
832 if (instance != server->reconnect_instance) {
833 cifs_server_unlock(server);
834 add_credits_and_wake_if(server, &credits, optype);
838 mid = server->ops->setup_async_request(server, rqst);
840 cifs_server_unlock(server);
841 add_credits_and_wake_if(server, &credits, optype);
845 mid->receive = receive;
846 mid->callback = callback;
847 mid->callback_data = cbdata;
848 mid->handle = handle;
849 mid->mid_state = MID_REQUEST_SUBMITTED;
851 /* put it on the pending_mid_q */
852 spin_lock(&server->mid_lock);
853 list_add_tail(&mid->qhead, &server->pending_mid_q);
854 spin_unlock(&server->mid_lock);
857 * Need to store the time in mid before calling I/O. For call_async,
858 * I/O response may come back and free the mid entry on another thread.
860 cifs_save_when_sent(mid);
861 rc = smb_send_rqst(server, 1, rqst, flags);
864 revert_current_mid(server, mid->credits);
865 server->sequence_number -= 2;
869 cifs_server_unlock(server);
874 add_credits_and_wake_if(server, &credits, optype);
880 * Send an SMB Request. No response info (other than return code)
881 * needs to be parsed.
883 * flags indicate the type of request buffer and how long to wait
884 * and whether to log NT STATUS code (error) before mapping it to POSIX error
888 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
889 char *in_buf, int flags)
896 iov[0].iov_base = in_buf;
897 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
898 flags |= CIFS_NO_RSP_BUF;
899 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
900 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
906 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
910 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
911 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
913 spin_lock(&server->mid_lock);
914 switch (mid->mid_state) {
915 case MID_RESPONSE_RECEIVED:
916 spin_unlock(&server->mid_lock);
918 case MID_RETRY_NEEDED:
921 case MID_RESPONSE_MALFORMED:
928 if (!(mid->mid_flags & MID_DELETED)) {
929 list_del_init(&mid->qhead);
930 mid->mid_flags |= MID_DELETED;
932 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
933 __func__, mid->mid, mid->mid_state);
936 spin_unlock(&server->mid_lock);
943 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
944 struct mid_q_entry *mid)
946 return server->ops->send_cancel ?
947 server->ops->send_cancel(server, rqst, mid) : 0;
951 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
954 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
956 dump_smb(mid->resp_buf, min_t(u32, 92, len));
958 /* convert the length into a more usable form */
962 struct smb_rqst rqst = { .rq_iov = iov,
965 iov[0].iov_base = mid->resp_buf;
967 iov[1].iov_base = (char *)mid->resp_buf + 4;
968 iov[1].iov_len = len - 4;
969 /* FIXME: add code to kill session */
970 rc = cifs_verify_signature(&rqst, server,
971 mid->sequence_number);
973 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
977 /* BB special case reconnect tid and uid here? */
978 return map_and_check_smb_error(mid, log_error);
982 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
983 struct smb_rqst *rqst)
986 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
987 struct mid_q_entry *mid;
989 if (rqst->rq_iov[0].iov_len != 4 ||
990 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
991 return ERR_PTR(-EIO);
993 rc = allocate_mid(ses, hdr, &mid);
996 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
1005 cifs_compound_callback(struct mid_q_entry *mid)
1007 struct TCP_Server_Info *server = mid->server;
1008 struct cifs_credits credits;
1010 credits.value = server->ops->get_credits(mid);
1011 credits.instance = server->reconnect_instance;
1013 add_credits(server, &credits, mid->optype);
1017 cifs_compound_last_callback(struct mid_q_entry *mid)
1019 cifs_compound_callback(mid);
1020 cifs_wake_up_task(mid);
1024 cifs_cancelled_callback(struct mid_q_entry *mid)
1026 cifs_compound_callback(mid);
1031 * Return a channel (master if none) of @ses that can be used to send
1034 * If we are currently binding a new channel (negprot/sess.setup),
1035 * return the new incomplete channel.
1037 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1045 index = (uint)atomic_inc_return(&ses->chan_seq);
1047 spin_lock(&ses->chan_lock);
1048 index %= ses->chan_count;
1049 spin_unlock(&ses->chan_lock);
1051 return ses->chans[index].server;
1055 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1056 struct TCP_Server_Info *server,
1057 const int flags, const int num_rqst, struct smb_rqst *rqst,
1058 int *resp_buf_type, struct kvec *resp_iov)
1060 int i, j, optype, rc = 0;
1061 struct mid_q_entry *midQ[MAX_COMPOUND];
1062 bool cancelled_mid[MAX_COMPOUND] = {false};
1063 struct cifs_credits credits[MAX_COMPOUND] = {
1064 { .value = 0, .instance = 0 }
1066 unsigned int instance;
1069 optype = flags & CIFS_OP_MASK;
1071 for (i = 0; i < num_rqst; i++)
1072 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1074 if (!ses || !ses->server || !server) {
1075 cifs_dbg(VFS, "Null session\n");
1079 spin_lock(&server->srv_lock);
1080 if (server->tcpStatus == CifsExiting) {
1081 spin_unlock(&server->srv_lock);
1084 spin_unlock(&server->srv_lock);
1087 * Wait for all the requests to become available.
1088 * This approach still leaves the possibility to be stuck waiting for
1089 * credits if the server doesn't grant credits to the outstanding
1090 * requests and if the client is completely idle, not generating any
1092 * This can be handled by the eventual session reconnect.
1094 rc = wait_for_compound_request(server, num_rqst, flags,
1099 for (i = 0; i < num_rqst; i++) {
1100 credits[i].value = 1;
1101 credits[i].instance = instance;
1105 * Make sure that we sign in the same order that we send on this socket
1106 * and avoid races inside tcp sendmsg code that could cause corruption
1110 cifs_server_lock(server);
1113 * All the parts of the compound chain belong obtained credits from the
1114 * same session. We can not use credits obtained from the previous
1115 * session to send this request. Check if there were reconnects after
1116 * we obtained credits and return -EAGAIN in such cases to let callers
1119 if (instance != server->reconnect_instance) {
1120 cifs_server_unlock(server);
1121 for (j = 0; j < num_rqst; j++)
1122 add_credits(server, &credits[j], optype);
1126 for (i = 0; i < num_rqst; i++) {
1127 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1128 if (IS_ERR(midQ[i])) {
1129 revert_current_mid(server, i);
1130 for (j = 0; j < i; j++)
1131 delete_mid(midQ[j]);
1132 cifs_server_unlock(server);
1134 /* Update # of requests on wire to server */
1135 for (j = 0; j < num_rqst; j++)
1136 add_credits(server, &credits[j], optype);
1137 return PTR_ERR(midQ[i]);
1140 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1141 midQ[i]->optype = optype;
1143 * Invoke callback for every part of the compound chain
1144 * to calculate credits properly. Wake up this thread only when
1145 * the last element is received.
1147 if (i < num_rqst - 1)
1148 midQ[i]->callback = cifs_compound_callback;
1150 midQ[i]->callback = cifs_compound_last_callback;
1152 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1154 for (i = 0; i < num_rqst; i++)
1155 cifs_save_when_sent(midQ[i]);
1158 revert_current_mid(server, num_rqst);
1159 server->sequence_number -= 2;
1162 cifs_server_unlock(server);
1165 * If sending failed for some reason or it is an oplock break that we
1166 * will not receive a response to - return credits back
1168 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1169 for (i = 0; i < num_rqst; i++)
1170 add_credits(server, &credits[i], optype);
1175 * At this point the request is passed to the network stack - we assume
1176 * that any credits taken from the server structure on the client have
1177 * been spent and we can't return them back. Once we receive responses
1178 * we will collect credits granted by the server in the mid callbacks
1179 * and add those credits to the server structure.
1183 * Compounding is never used during session establish.
1185 spin_lock(&ses->ses_lock);
1186 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1187 spin_unlock(&ses->ses_lock);
1189 cifs_server_lock(server);
1190 smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec);
1191 cifs_server_unlock(server);
1193 spin_lock(&ses->ses_lock);
1195 spin_unlock(&ses->ses_lock);
1197 for (i = 0; i < num_rqst; i++) {
1198 rc = wait_for_response(server, midQ[i]);
1203 for (; i < num_rqst; i++) {
1204 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1205 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1206 send_cancel(server, &rqst[i], midQ[i]);
1207 spin_lock(&server->mid_lock);
1208 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1209 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED) {
1210 midQ[i]->callback = cifs_cancelled_callback;
1211 cancelled_mid[i] = true;
1212 credits[i].value = 0;
1214 spin_unlock(&server->mid_lock);
1218 for (i = 0; i < num_rqst; i++) {
1222 rc = cifs_sync_mid_result(midQ[i], server);
1224 /* mark this mid as cancelled to not free it below */
1225 cancelled_mid[i] = true;
1229 if (!midQ[i]->resp_buf ||
1230 midQ[i]->mid_state != MID_RESPONSE_RECEIVED) {
1232 cifs_dbg(FYI, "Bad MID state?\n");
1236 buf = (char *)midQ[i]->resp_buf;
1237 resp_iov[i].iov_base = buf;
1238 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1239 HEADER_PREAMBLE_SIZE(server);
1241 if (midQ[i]->large_buf)
1242 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1244 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1246 rc = server->ops->check_receive(midQ[i], server,
1247 flags & CIFS_LOG_ERROR);
1249 /* mark it so buf will not be freed by delete_mid */
1250 if ((flags & CIFS_NO_RSP_BUF) == 0)
1251 midQ[i]->resp_buf = NULL;
1256 * Compounding is never used during session establish.
1258 spin_lock(&ses->ses_lock);
1259 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1261 .iov_base = resp_iov[0].iov_base,
1262 .iov_len = resp_iov[0].iov_len
1264 spin_unlock(&ses->ses_lock);
1265 cifs_server_lock(server);
1266 smb311_update_preauth_hash(ses, server, &iov, 1);
1267 cifs_server_unlock(server);
1268 spin_lock(&ses->ses_lock);
1270 spin_unlock(&ses->ses_lock);
1274 * This will dequeue all mids. After this it is important that the
1275 * demultiplex_thread will not process any of these mids any futher.
1276 * This is prevented above by using a noop callback that will not
1277 * wake this thread except for the very last PDU.
1279 for (i = 0; i < num_rqst; i++) {
1280 if (!cancelled_mid[i])
1281 delete_mid(midQ[i]);
1288 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1289 struct TCP_Server_Info *server,
1290 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1291 struct kvec *resp_iov)
1293 return compound_send_recv(xid, ses, server, flags, 1,
1294 rqst, resp_buf_type, resp_iov);
1298 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1299 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1300 const int flags, struct kvec *resp_iov)
1302 struct smb_rqst rqst;
1303 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1306 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1307 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1310 /* otherwise cifs_send_recv below sets resp_buf_type */
1311 *resp_buf_type = CIFS_NO_BUFFER;
1317 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1318 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1320 new_iov[0].iov_base = new_iov[1].iov_base;
1321 new_iov[0].iov_len = 4;
1322 new_iov[1].iov_base += 4;
1323 new_iov[1].iov_len -= 4;
1325 memset(&rqst, 0, sizeof(struct smb_rqst));
1326 rqst.rq_iov = new_iov;
1327 rqst.rq_nvec = n_vec + 1;
1329 rc = cifs_send_recv(xid, ses, ses->server,
1330 &rqst, resp_buf_type, flags, resp_iov);
1331 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1337 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1338 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1339 int *pbytes_returned, const int flags)
1342 struct mid_q_entry *midQ;
1343 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1344 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1345 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1346 struct cifs_credits credits = { .value = 1, .instance = 0 };
1347 struct TCP_Server_Info *server;
1350 cifs_dbg(VFS, "Null smb session\n");
1353 server = ses->server;
1354 if (server == NULL) {
1355 cifs_dbg(VFS, "Null tcp session\n");
1359 spin_lock(&server->srv_lock);
1360 if (server->tcpStatus == CifsExiting) {
1361 spin_unlock(&server->srv_lock);
1364 spin_unlock(&server->srv_lock);
1366 /* Ensure that we do not send more than 50 overlapping requests
1367 to the same server. We may make this configurable later or
1370 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1371 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1376 rc = wait_for_free_request(server, flags, &credits.instance);
1380 /* make sure that we sign in the same order that we send on this socket
1381 and avoid races inside tcp sendmsg code that could cause corruption
1384 cifs_server_lock(server);
1386 rc = allocate_mid(ses, in_buf, &midQ);
1388 cifs_server_unlock(server);
1389 /* Update # of requests on wire to server */
1390 add_credits(server, &credits, 0);
1394 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1396 cifs_server_unlock(server);
1400 midQ->mid_state = MID_REQUEST_SUBMITTED;
1402 rc = smb_send(server, in_buf, len);
1403 cifs_save_when_sent(midQ);
1406 server->sequence_number -= 2;
1408 cifs_server_unlock(server);
1413 rc = wait_for_response(server, midQ);
1415 send_cancel(server, &rqst, midQ);
1416 spin_lock(&server->mid_lock);
1417 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1418 /* no longer considered to be "in-flight" */
1419 midQ->callback = release_mid;
1420 spin_unlock(&server->mid_lock);
1421 add_credits(server, &credits, 0);
1424 spin_unlock(&server->mid_lock);
1427 rc = cifs_sync_mid_result(midQ, server);
1429 add_credits(server, &credits, 0);
1433 if (!midQ->resp_buf || !out_buf ||
1434 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1436 cifs_server_dbg(VFS, "Bad MID state?\n");
1440 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1441 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1442 rc = cifs_check_receive(midQ, server, 0);
1445 add_credits(server, &credits, 0);
1450 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1451 blocking lock to return. */
1454 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1455 struct smb_hdr *in_buf,
1456 struct smb_hdr *out_buf)
1459 struct cifs_ses *ses = tcon->ses;
1460 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1462 /* We just modify the current in_buf to change
1463 the type of lock from LOCKING_ANDX_SHARED_LOCK
1464 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1465 LOCKING_ANDX_CANCEL_LOCK. */
1467 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1469 pSMB->hdr.Mid = get_next_mid(ses->server);
1471 return SendReceive(xid, ses, in_buf, out_buf,
1472 &bytes_returned, 0);
1476 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1477 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1478 int *pbytes_returned)
1482 struct mid_q_entry *midQ;
1483 struct cifs_ses *ses;
1484 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1485 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1486 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1487 unsigned int instance;
1488 struct TCP_Server_Info *server;
1490 if (tcon == NULL || tcon->ses == NULL) {
1491 cifs_dbg(VFS, "Null smb session\n");
1495 server = ses->server;
1497 if (server == NULL) {
1498 cifs_dbg(VFS, "Null tcp session\n");
1502 spin_lock(&server->srv_lock);
1503 if (server->tcpStatus == CifsExiting) {
1504 spin_unlock(&server->srv_lock);
1507 spin_unlock(&server->srv_lock);
1509 /* Ensure that we do not send more than 50 overlapping requests
1510 to the same server. We may make this configurable later or
1513 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1514 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1519 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1523 /* make sure that we sign in the same order that we send on this socket
1524 and avoid races inside tcp sendmsg code that could cause corruption
1527 cifs_server_lock(server);
1529 rc = allocate_mid(ses, in_buf, &midQ);
1531 cifs_server_unlock(server);
1535 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1538 cifs_server_unlock(server);
1542 midQ->mid_state = MID_REQUEST_SUBMITTED;
1543 rc = smb_send(server, in_buf, len);
1544 cifs_save_when_sent(midQ);
1547 server->sequence_number -= 2;
1549 cifs_server_unlock(server);
1556 /* Wait for a reply - allow signals to interrupt. */
1557 rc = wait_event_interruptible(server->response_q,
1558 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1559 ((server->tcpStatus != CifsGood) &&
1560 (server->tcpStatus != CifsNew)));
1562 /* Were we interrupted by a signal ? */
1563 spin_lock(&server->srv_lock);
1564 if ((rc == -ERESTARTSYS) &&
1565 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1566 ((server->tcpStatus == CifsGood) ||
1567 (server->tcpStatus == CifsNew))) {
1568 spin_unlock(&server->srv_lock);
1570 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1571 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1572 blocking lock to return. */
1573 rc = send_cancel(server, &rqst, midQ);
1579 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1580 to cause the blocking lock to return. */
1582 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1584 /* If we get -ENOLCK back the lock may have
1585 already been removed. Don't exit in this case. */
1586 if (rc && rc != -ENOLCK) {
1592 rc = wait_for_response(server, midQ);
1594 send_cancel(server, &rqst, midQ);
1595 spin_lock(&server->mid_lock);
1596 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1597 /* no longer considered to be "in-flight" */
1598 midQ->callback = release_mid;
1599 spin_unlock(&server->mid_lock);
1602 spin_unlock(&server->mid_lock);
1605 /* We got the response - restart system call. */
1607 spin_lock(&server->srv_lock);
1609 spin_unlock(&server->srv_lock);
1611 rc = cifs_sync_mid_result(midQ, server);
1615 /* rcvd frame is ok */
1616 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1618 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1622 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1623 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1624 rc = cifs_check_receive(midQ, server, 0);
1627 if (rstart && rc == -EACCES)
1628 return -ERESTARTSYS;
1633 * Discard any remaining data in the current SMB. To do this, we borrow the
1637 cifs_discard_remaining_data(struct TCP_Server_Info *server)
1639 unsigned int rfclen = server->pdu_size;
1640 int remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
1643 while (remaining > 0) {
1646 length = cifs_discard_from_socket(server,
1647 min_t(size_t, remaining,
1648 CIFSMaxBufSize + MAX_HEADER_SIZE(server)));
1651 server->total_read += length;
1652 remaining -= length;
1659 __cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid,
1664 length = cifs_discard_remaining_data(server);
1665 dequeue_mid(mid, malformed);
1666 mid->resp_buf = server->smallbuf;
1667 server->smallbuf = NULL;
1672 cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1674 struct cifs_readdata *rdata = mid->callback_data;
1676 return __cifs_readv_discard(server, mid, rdata->result);
1680 cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1683 unsigned int data_offset, data_len;
1684 struct cifs_readdata *rdata = mid->callback_data;
1685 char *buf = server->smallbuf;
1686 unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server);
1687 bool use_rdma_mr = false;
1689 cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
1690 __func__, mid->mid, rdata->offset, rdata->bytes);
1693 * read the rest of READ_RSP header (sans Data array), or whatever we
1694 * can if there's not enough data. At this point, we've read down to
1697 len = min_t(unsigned int, buflen, server->vals->read_rsp_size) -
1698 HEADER_SIZE(server) + 1;
1700 length = cifs_read_from_socket(server,
1701 buf + HEADER_SIZE(server) - 1, len);
1704 server->total_read += length;
1706 if (server->ops->is_session_expired &&
1707 server->ops->is_session_expired(buf)) {
1708 cifs_reconnect(server, true);
1712 if (server->ops->is_status_pending &&
1713 server->ops->is_status_pending(buf, server)) {
1714 cifs_discard_remaining_data(server);
1718 /* set up first two iov for signature check and to get credits */
1719 rdata->iov[0].iov_base = buf;
1720 rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server);
1721 rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server);
1722 rdata->iov[1].iov_len =
1723 server->total_read - HEADER_PREAMBLE_SIZE(server);
1724 cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
1725 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
1726 cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
1727 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
1729 /* Was the SMB read successful? */
1730 rdata->result = server->ops->map_error(buf, false);
1731 if (rdata->result != 0) {
1732 cifs_dbg(FYI, "%s: server returned error %d\n",
1733 __func__, rdata->result);
1734 /* normal error on read response */
1735 return __cifs_readv_discard(server, mid, false);
1738 /* Is there enough to get to the rest of the READ_RSP header? */
1739 if (server->total_read < server->vals->read_rsp_size) {
1740 cifs_dbg(FYI, "%s: server returned short header. got=%u expected=%zu\n",
1741 __func__, server->total_read,
1742 server->vals->read_rsp_size);
1743 rdata->result = -EIO;
1744 return cifs_readv_discard(server, mid);
1747 data_offset = server->ops->read_data_offset(buf) +
1748 HEADER_PREAMBLE_SIZE(server);
1749 if (data_offset < server->total_read) {
1751 * win2k8 sometimes sends an offset of 0 when the read
1752 * is beyond the EOF. Treat it as if the data starts just after
1755 cifs_dbg(FYI, "%s: data offset (%u) inside read response header\n",
1756 __func__, data_offset);
1757 data_offset = server->total_read;
1758 } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) {
1759 /* data_offset is beyond the end of smallbuf */
1760 cifs_dbg(FYI, "%s: data offset (%u) beyond end of smallbuf\n",
1761 __func__, data_offset);
1762 rdata->result = -EIO;
1763 return cifs_readv_discard(server, mid);
1766 cifs_dbg(FYI, "%s: total_read=%u data_offset=%u\n",
1767 __func__, server->total_read, data_offset);
1769 len = data_offset - server->total_read;
1771 /* read any junk before data into the rest of smallbuf */
1772 length = cifs_read_from_socket(server,
1773 buf + server->total_read, len);
1776 server->total_read += length;
1779 /* how much data is in the response? */
1780 #ifdef CONFIG_CIFS_SMB_DIRECT
1781 use_rdma_mr = rdata->mr;
1783 data_len = server->ops->read_data_length(buf, use_rdma_mr);
1784 if (!use_rdma_mr && (data_offset + data_len > buflen)) {
1785 /* data_len is corrupt -- discard frame */
1786 rdata->result = -EIO;
1787 return cifs_readv_discard(server, mid);
1790 length = rdata->read_into_pages(server, rdata, data_len);
1794 server->total_read += length;
1796 cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n",
1797 server->total_read, buflen, data_len);
1799 /* discard anything left over */
1800 if (server->total_read < buflen)
1801 return cifs_readv_discard(server, mid);
1803 dequeue_mid(mid, false);
1804 mid->resp_buf = server->smallbuf;
1805 server->smallbuf = NULL;