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 <linux/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 /* 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;
267 buflen += iov_iter_count(&rqst->rq_iter);
272 __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
273 struct smb_rqst *rqst)
278 unsigned int send_length = 0;
280 sigset_t mask, oldmask;
281 size_t total_len = 0, sent, size;
282 struct socket *ssocket = server->ssocket;
283 struct msghdr smb_msg = {};
284 __be32 rfc1002_marker;
286 cifs_in_send_inc(server);
287 if (cifs_rdma_enabled(server)) {
288 /* return -EAGAIN when connecting or reconnecting */
290 if (server->smbd_conn)
291 rc = smbd_send(server, num_rqst, rqst);
300 if (fatal_signal_pending(current)) {
301 cifs_dbg(FYI, "signal pending before send request\n");
306 /* cork the socket */
307 tcp_sock_set_cork(ssocket->sk, true);
309 for (j = 0; j < num_rqst; j++)
310 send_length += smb_rqst_len(server, &rqst[j]);
311 rfc1002_marker = cpu_to_be32(send_length);
314 * We should not allow signals to interrupt the network send because
315 * any partial send will cause session reconnects thus increasing
316 * latency of system calls and overload a server with unnecessary
321 sigprocmask(SIG_BLOCK, &mask, &oldmask);
323 /* Generate a rfc1002 marker for SMB2+ */
324 if (!is_smb1(server)) {
326 .iov_base = &rfc1002_marker,
329 iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, &hiov, 1, 4);
330 rc = smb_send_kvec(server, &smb_msg, &sent);
338 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", send_length);
340 for (j = 0; j < num_rqst; j++) {
341 iov = rqst[j].rq_iov;
342 n_vec = rqst[j].rq_nvec;
345 for (i = 0; i < n_vec; i++) {
346 dump_smb(iov[i].iov_base, iov[i].iov_len);
347 size += iov[i].iov_len;
350 iov_iter_kvec(&smb_msg.msg_iter, ITER_SOURCE, iov, n_vec, size);
352 rc = smb_send_kvec(server, &smb_msg, &sent);
358 if (iov_iter_count(&rqst[j].rq_iter) > 0) {
359 smb_msg.msg_iter = rqst[j].rq_iter;
360 rc = smb_send_kvec(server, &smb_msg, &sent);
369 sigprocmask(SIG_SETMASK, &oldmask, NULL);
372 * If signal is pending but we have already sent the whole packet to
373 * the server we need to return success status to allow a corresponding
374 * mid entry to be kept in the pending requests queue thus allowing
375 * to handle responses from the server by the client.
377 * If only part of the packet has been sent there is no need to hide
378 * interrupt because the session will be reconnected anyway, so there
379 * won't be any response from the server to handle.
382 if (signal_pending(current) && (total_len != send_length)) {
383 cifs_dbg(FYI, "signal is pending after attempt to send\n");
388 tcp_sock_set_cork(ssocket->sk, false);
390 if ((total_len > 0) && (total_len != send_length)) {
391 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
392 send_length, total_len);
394 * If we have only sent part of an SMB then the next SMB could
395 * be taken as the remainder of this one. We need to kill the
396 * socket so the server throws away the partial SMB
398 cifs_signal_cifsd_for_reconnect(server, false);
399 trace_smb3_partial_send_reconnect(server->CurrentMid,
400 server->conn_id, server->hostname);
404 * there's hardly any use for the layers above to know the
405 * actual error code here. All they should do at this point is
406 * to retry the connection and hope it goes away.
408 if (rc < 0 && rc != -EINTR && rc != -EAGAIN) {
409 cifs_server_dbg(VFS, "Error %d sending data on socket to server\n",
412 cifs_signal_cifsd_for_reconnect(server, false);
416 cifs_in_send_dec(server);
420 struct send_req_vars {
421 struct smb2_transform_hdr tr_hdr;
422 struct smb_rqst rqst[MAX_COMPOUND];
427 smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
428 struct smb_rqst *rqst, int flags)
430 struct send_req_vars *vars;
431 struct smb_rqst *cur_rqst;
435 if (!(flags & CIFS_TRANSFORM_REQ))
436 return __smb_send_rqst(server, num_rqst, rqst);
438 if (WARN_ON_ONCE(num_rqst > MAX_COMPOUND - 1))
441 if (!server->ops->init_transform_rq) {
442 cifs_server_dbg(VFS, "Encryption requested but transform callback is missing\n");
446 vars = kzalloc(sizeof(*vars), GFP_NOFS);
449 cur_rqst = vars->rqst;
452 iov->iov_base = &vars->tr_hdr;
453 iov->iov_len = sizeof(vars->tr_hdr);
454 cur_rqst[0].rq_iov = iov;
455 cur_rqst[0].rq_nvec = 1;
457 rc = server->ops->init_transform_rq(server, num_rqst + 1,
462 rc = __smb_send_rqst(server, num_rqst + 1, &cur_rqst[0]);
463 smb3_free_compound_rqst(num_rqst, &cur_rqst[1]);
470 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
471 unsigned int smb_buf_length)
474 struct smb_rqst rqst = { .rq_iov = iov,
477 iov[0].iov_base = smb_buffer;
479 iov[1].iov_base = (char *)smb_buffer + 4;
480 iov[1].iov_len = smb_buf_length;
482 return __smb_send_rqst(server, 1, &rqst);
486 wait_for_free_credits(struct TCP_Server_Info *server, const int num_credits,
487 const int timeout, const int flags,
488 unsigned int *instance)
494 int scredits, in_flight;
497 t = MAX_JIFFY_OFFSET;
499 t = msecs_to_jiffies(timeout);
501 optype = flags & CIFS_OP_MASK;
505 credits = server->ops->get_credits_field(server, optype);
506 /* Since an echo is already inflight, no need to wait to send another */
507 if (*credits <= 0 && optype == CIFS_ECHO_OP)
510 spin_lock(&server->req_lock);
511 if ((flags & CIFS_TIMEOUT_MASK) == CIFS_NON_BLOCKING) {
512 /* oplock breaks must not be held up */
514 if (server->in_flight > server->max_in_flight)
515 server->max_in_flight = server->in_flight;
517 *instance = server->reconnect_instance;
519 in_flight = server->in_flight;
520 spin_unlock(&server->req_lock);
522 trace_smb3_nblk_credits(server->CurrentMid,
523 server->conn_id, server->hostname, scredits, -1, in_flight);
524 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
525 __func__, 1, scredits);
531 spin_unlock(&server->req_lock);
533 spin_lock(&server->srv_lock);
534 if (server->tcpStatus == CifsExiting) {
535 spin_unlock(&server->srv_lock);
538 spin_unlock(&server->srv_lock);
540 spin_lock(&server->req_lock);
541 if (*credits < num_credits) {
543 spin_unlock(&server->req_lock);
545 cifs_num_waiters_inc(server);
546 rc = wait_event_killable_timeout(server->request_q,
547 has_credits(server, credits, num_credits), t);
548 cifs_num_waiters_dec(server);
550 spin_lock(&server->req_lock);
552 in_flight = server->in_flight;
553 spin_unlock(&server->req_lock);
555 trace_smb3_credit_timeout(server->CurrentMid,
556 server->conn_id, server->hostname, scredits,
557 num_credits, in_flight);
558 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
562 if (rc == -ERESTARTSYS)
564 spin_lock(&server->req_lock);
567 * For normal commands, reserve the last MAX_COMPOUND
568 * credits to compound requests.
569 * Otherwise these compounds could be permanently
570 * starved for credits by single-credit requests.
572 * To prevent spinning CPU, block this thread until
573 * there are >MAX_COMPOUND credits available.
574 * But only do this is we already have a lot of
575 * credits in flight to avoid triggering this check
576 * for servers that are slow to hand out credits on
579 if (!optype && num_credits == 1 &&
580 server->in_flight > 2 * MAX_COMPOUND &&
581 *credits <= MAX_COMPOUND) {
582 spin_unlock(&server->req_lock);
584 cifs_num_waiters_inc(server);
585 rc = wait_event_killable_timeout(
587 has_credits(server, credits,
590 cifs_num_waiters_dec(server);
592 spin_lock(&server->req_lock);
594 in_flight = server->in_flight;
595 spin_unlock(&server->req_lock);
597 trace_smb3_credit_timeout(
599 server->conn_id, server->hostname,
600 scredits, num_credits, in_flight);
601 cifs_server_dbg(VFS, "wait timed out after %d ms\n",
605 if (rc == -ERESTARTSYS)
607 spin_lock(&server->req_lock);
612 * Can not count locking commands against total
613 * as they are allowed to block on server.
616 /* update # of requests on the wire to server */
617 if ((flags & CIFS_TIMEOUT_MASK) != CIFS_BLOCKING_OP) {
618 *credits -= num_credits;
619 server->in_flight += num_credits;
620 if (server->in_flight > server->max_in_flight)
621 server->max_in_flight = server->in_flight;
622 *instance = server->reconnect_instance;
625 in_flight = server->in_flight;
626 spin_unlock(&server->req_lock);
628 trace_smb3_waitff_credits(server->CurrentMid,
629 server->conn_id, server->hostname, scredits,
630 -(num_credits), in_flight);
631 cifs_dbg(FYI, "%s: remove %u credits total=%d\n",
632 __func__, num_credits, scredits);
640 wait_for_free_request(struct TCP_Server_Info *server, const int flags,
641 unsigned int *instance)
643 return wait_for_free_credits(server, 1, -1, flags,
648 wait_for_compound_request(struct TCP_Server_Info *server, int num,
649 const int flags, unsigned int *instance)
652 int scredits, in_flight;
654 credits = server->ops->get_credits_field(server, flags & CIFS_OP_MASK);
656 spin_lock(&server->req_lock);
658 in_flight = server->in_flight;
660 if (*credits < num) {
662 * If the server is tight on resources or just gives us less
663 * credits for other reasons (e.g. requests are coming out of
664 * order and the server delays granting more credits until it
665 * processes a missing mid) and we exhausted most available
666 * credits there may be situations when we try to send
667 * a compound request but we don't have enough credits. At this
668 * point the client needs to decide if it should wait for
669 * additional credits or fail the request. If at least one
670 * request is in flight there is a high probability that the
671 * server will return enough credits to satisfy this compound
674 * Return immediately if no requests in flight since we will be
675 * stuck on waiting for credits.
677 if (server->in_flight == 0) {
678 spin_unlock(&server->req_lock);
679 trace_smb3_insufficient_credits(server->CurrentMid,
680 server->conn_id, server->hostname, scredits,
682 cifs_dbg(FYI, "%s: %d requests in flight, needed %d total=%d\n",
683 __func__, in_flight, num, scredits);
687 spin_unlock(&server->req_lock);
689 return wait_for_free_credits(server, num, 60000, flags,
694 cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
695 unsigned int *num, struct cifs_credits *credits)
699 credits->instance = server->reconnect_instance;
703 static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
704 struct mid_q_entry **ppmidQ)
706 spin_lock(&ses->ses_lock);
707 if (ses->ses_status == SES_NEW) {
708 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
709 (in_buf->Command != SMB_COM_NEGOTIATE)) {
710 spin_unlock(&ses->ses_lock);
713 /* else ok - we are setting up session */
716 if (ses->ses_status == SES_EXITING) {
717 /* check if SMB session is bad because we are setting it up */
718 if (in_buf->Command != SMB_COM_LOGOFF_ANDX) {
719 spin_unlock(&ses->ses_lock);
722 /* else ok - we are shutting down session */
724 spin_unlock(&ses->ses_lock);
726 *ppmidQ = alloc_mid(in_buf, ses->server);
729 spin_lock(&ses->server->mid_lock);
730 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
731 spin_unlock(&ses->server->mid_lock);
736 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
740 error = wait_event_state(server->response_q,
741 midQ->mid_state != MID_REQUEST_SUBMITTED &&
742 midQ->mid_state != MID_RESPONSE_RECEIVED,
743 (TASK_KILLABLE|TASK_FREEZABLE_UNSAFE));
751 cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
754 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
755 struct mid_q_entry *mid;
757 if (rqst->rq_iov[0].iov_len != 4 ||
758 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
759 return ERR_PTR(-EIO);
761 /* enable signing if server requires it */
763 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
765 mid = alloc_mid(hdr, server);
767 return ERR_PTR(-ENOMEM);
769 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
779 * Send a SMB request and set the callback function in the mid to handle
780 * the result. Caller is responsible for dealing with timeouts.
783 cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
784 mid_receive_t *receive, mid_callback_t *callback,
785 mid_handle_t *handle, void *cbdata, const int flags,
786 const struct cifs_credits *exist_credits)
789 struct mid_q_entry *mid;
790 struct cifs_credits credits = { .value = 0, .instance = 0 };
791 unsigned int instance;
794 optype = flags & CIFS_OP_MASK;
796 if ((flags & CIFS_HAS_CREDITS) == 0) {
797 rc = wait_for_free_request(server, flags, &instance);
801 credits.instance = instance;
803 instance = exist_credits->instance;
805 cifs_server_lock(server);
808 * We can't use credits obtained from the previous session to send this
809 * request. Check if there were reconnects after we obtained credits and
810 * return -EAGAIN in such cases to let callers handle it.
812 if (instance != server->reconnect_instance) {
813 cifs_server_unlock(server);
814 add_credits_and_wake_if(server, &credits, optype);
818 mid = server->ops->setup_async_request(server, rqst);
820 cifs_server_unlock(server);
821 add_credits_and_wake_if(server, &credits, optype);
825 mid->receive = receive;
826 mid->callback = callback;
827 mid->callback_data = cbdata;
828 mid->handle = handle;
829 mid->mid_state = MID_REQUEST_SUBMITTED;
831 /* put it on the pending_mid_q */
832 spin_lock(&server->mid_lock);
833 list_add_tail(&mid->qhead, &server->pending_mid_q);
834 spin_unlock(&server->mid_lock);
837 * Need to store the time in mid before calling I/O. For call_async,
838 * I/O response may come back and free the mid entry on another thread.
840 cifs_save_when_sent(mid);
841 rc = smb_send_rqst(server, 1, rqst, flags);
844 revert_current_mid(server, mid->credits);
845 server->sequence_number -= 2;
849 cifs_server_unlock(server);
854 add_credits_and_wake_if(server, &credits, optype);
860 * Send an SMB Request. No response info (other than return code)
861 * needs to be parsed.
863 * flags indicate the type of request buffer and how long to wait
864 * and whether to log NT STATUS code (error) before mapping it to POSIX error
868 SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
869 char *in_buf, int flags)
876 iov[0].iov_base = in_buf;
877 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
878 flags |= CIFS_NO_RSP_BUF;
879 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
880 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
886 cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
890 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
891 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
893 spin_lock(&server->mid_lock);
894 switch (mid->mid_state) {
895 case MID_RESPONSE_READY:
896 spin_unlock(&server->mid_lock);
898 case MID_RETRY_NEEDED:
901 case MID_RESPONSE_MALFORMED:
908 if (!(mid->mid_flags & MID_DELETED)) {
909 list_del_init(&mid->qhead);
910 mid->mid_flags |= MID_DELETED;
912 cifs_server_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
913 __func__, mid->mid, mid->mid_state);
916 spin_unlock(&server->mid_lock);
923 send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
924 struct mid_q_entry *mid)
926 return server->ops->send_cancel ?
927 server->ops->send_cancel(server, rqst, mid) : 0;
931 cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
934 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
936 dump_smb(mid->resp_buf, min_t(u32, 92, len));
938 /* convert the length into a more usable form */
942 struct smb_rqst rqst = { .rq_iov = iov,
945 iov[0].iov_base = mid->resp_buf;
947 iov[1].iov_base = (char *)mid->resp_buf + 4;
948 iov[1].iov_len = len - 4;
949 /* FIXME: add code to kill session */
950 rc = cifs_verify_signature(&rqst, server,
951 mid->sequence_number);
953 cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
957 /* BB special case reconnect tid and uid here? */
958 return map_and_check_smb_error(mid, log_error);
962 cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
963 struct smb_rqst *rqst)
966 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
967 struct mid_q_entry *mid;
969 if (rqst->rq_iov[0].iov_len != 4 ||
970 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
971 return ERR_PTR(-EIO);
973 rc = allocate_mid(ses, hdr, &mid);
976 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
985 cifs_compound_callback(struct mid_q_entry *mid)
987 struct TCP_Server_Info *server = mid->server;
988 struct cifs_credits credits;
990 credits.value = server->ops->get_credits(mid);
991 credits.instance = server->reconnect_instance;
993 add_credits(server, &credits, mid->optype);
995 if (mid->mid_state == MID_RESPONSE_RECEIVED)
996 mid->mid_state = MID_RESPONSE_READY;
1000 cifs_compound_last_callback(struct mid_q_entry *mid)
1002 cifs_compound_callback(mid);
1003 cifs_wake_up_task(mid);
1007 cifs_cancelled_callback(struct mid_q_entry *mid)
1009 cifs_compound_callback(mid);
1014 * Return a channel (master if none) of @ses that can be used to send
1017 * If we are currently binding a new channel (negprot/sess.setup),
1018 * return the new incomplete channel.
1020 struct TCP_Server_Info *cifs_pick_channel(struct cifs_ses *ses)
1023 unsigned int min_in_flight = UINT_MAX, max_in_flight = 0;
1024 struct TCP_Server_Info *server = NULL;
1030 spin_lock(&ses->chan_lock);
1031 for (i = 0; i < ses->chan_count; i++) {
1032 server = ses->chans[i].server;
1033 if (!server || server->terminate)
1036 if (CIFS_CHAN_NEEDS_RECONNECT(ses, i))
1040 * strictly speaking, we should pick up req_lock to read
1041 * server->in_flight. But it shouldn't matter much here if we
1042 * race while reading this data. The worst that can happen is
1043 * that we could use a channel that's not least loaded. Avoiding
1044 * taking the lock could help reduce wait time, which is
1045 * important for this function
1047 if (server->in_flight < min_in_flight) {
1048 min_in_flight = server->in_flight;
1051 if (server->in_flight > max_in_flight)
1052 max_in_flight = server->in_flight;
1055 /* if all channels are equally loaded, fall back to round-robin */
1056 if (min_in_flight == max_in_flight) {
1057 index = (uint)atomic_inc_return(&ses->chan_seq);
1058 index %= ses->chan_count;
1060 spin_unlock(&ses->chan_lock);
1062 return ses->chans[index].server;
1066 compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
1067 struct TCP_Server_Info *server,
1068 const int flags, const int num_rqst, struct smb_rqst *rqst,
1069 int *resp_buf_type, struct kvec *resp_iov)
1071 int i, j, optype, rc = 0;
1072 struct mid_q_entry *midQ[MAX_COMPOUND];
1073 bool cancelled_mid[MAX_COMPOUND] = {false};
1074 struct cifs_credits credits[MAX_COMPOUND] = {
1075 { .value = 0, .instance = 0 }
1077 unsigned int instance;
1080 optype = flags & CIFS_OP_MASK;
1082 for (i = 0; i < num_rqst; i++)
1083 resp_buf_type[i] = CIFS_NO_BUFFER; /* no response buf yet */
1085 if (!ses || !ses->server || !server) {
1086 cifs_dbg(VFS, "Null session\n");
1090 spin_lock(&server->srv_lock);
1091 if (server->tcpStatus == CifsExiting) {
1092 spin_unlock(&server->srv_lock);
1095 spin_unlock(&server->srv_lock);
1098 * Wait for all the requests to become available.
1099 * This approach still leaves the possibility to be stuck waiting for
1100 * credits if the server doesn't grant credits to the outstanding
1101 * requests and if the client is completely idle, not generating any
1103 * This can be handled by the eventual session reconnect.
1105 rc = wait_for_compound_request(server, num_rqst, flags,
1110 for (i = 0; i < num_rqst; i++) {
1111 credits[i].value = 1;
1112 credits[i].instance = instance;
1116 * Make sure that we sign in the same order that we send on this socket
1117 * and avoid races inside tcp sendmsg code that could cause corruption
1121 cifs_server_lock(server);
1124 * All the parts of the compound chain belong obtained credits from the
1125 * same session. We can not use credits obtained from the previous
1126 * session to send this request. Check if there were reconnects after
1127 * we obtained credits and return -EAGAIN in such cases to let callers
1130 if (instance != server->reconnect_instance) {
1131 cifs_server_unlock(server);
1132 for (j = 0; j < num_rqst; j++)
1133 add_credits(server, &credits[j], optype);
1137 for (i = 0; i < num_rqst; i++) {
1138 midQ[i] = server->ops->setup_request(ses, server, &rqst[i]);
1139 if (IS_ERR(midQ[i])) {
1140 revert_current_mid(server, i);
1141 for (j = 0; j < i; j++)
1142 delete_mid(midQ[j]);
1143 cifs_server_unlock(server);
1145 /* Update # of requests on wire to server */
1146 for (j = 0; j < num_rqst; j++)
1147 add_credits(server, &credits[j], optype);
1148 return PTR_ERR(midQ[i]);
1151 midQ[i]->mid_state = MID_REQUEST_SUBMITTED;
1152 midQ[i]->optype = optype;
1154 * Invoke callback for every part of the compound chain
1155 * to calculate credits properly. Wake up this thread only when
1156 * the last element is received.
1158 if (i < num_rqst - 1)
1159 midQ[i]->callback = cifs_compound_callback;
1161 midQ[i]->callback = cifs_compound_last_callback;
1163 rc = smb_send_rqst(server, num_rqst, rqst, flags);
1165 for (i = 0; i < num_rqst; i++)
1166 cifs_save_when_sent(midQ[i]);
1169 revert_current_mid(server, num_rqst);
1170 server->sequence_number -= 2;
1173 cifs_server_unlock(server);
1176 * If sending failed for some reason or it is an oplock break that we
1177 * will not receive a response to - return credits back
1179 if (rc < 0 || (flags & CIFS_NO_SRV_RSP)) {
1180 for (i = 0; i < num_rqst; i++)
1181 add_credits(server, &credits[i], optype);
1186 * At this point the request is passed to the network stack - we assume
1187 * that any credits taken from the server structure on the client have
1188 * been spent and we can't return them back. Once we receive responses
1189 * we will collect credits granted by the server in the mid callbacks
1190 * and add those credits to the server structure.
1194 * Compounding is never used during session establish.
1196 spin_lock(&ses->ses_lock);
1197 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1198 spin_unlock(&ses->ses_lock);
1200 cifs_server_lock(server);
1201 smb311_update_preauth_hash(ses, server, rqst[0].rq_iov, rqst[0].rq_nvec);
1202 cifs_server_unlock(server);
1204 spin_lock(&ses->ses_lock);
1206 spin_unlock(&ses->ses_lock);
1208 for (i = 0; i < num_rqst; i++) {
1209 rc = wait_for_response(server, midQ[i]);
1214 for (; i < num_rqst; i++) {
1215 cifs_server_dbg(FYI, "Cancelling wait for mid %llu cmd: %d\n",
1216 midQ[i]->mid, le16_to_cpu(midQ[i]->command));
1217 send_cancel(server, &rqst[i], midQ[i]);
1218 spin_lock(&server->mid_lock);
1219 midQ[i]->mid_flags |= MID_WAIT_CANCELLED;
1220 if (midQ[i]->mid_state == MID_REQUEST_SUBMITTED ||
1221 midQ[i]->mid_state == MID_RESPONSE_RECEIVED) {
1222 midQ[i]->callback = cifs_cancelled_callback;
1223 cancelled_mid[i] = true;
1224 credits[i].value = 0;
1226 spin_unlock(&server->mid_lock);
1230 for (i = 0; i < num_rqst; i++) {
1234 rc = cifs_sync_mid_result(midQ[i], server);
1236 /* mark this mid as cancelled to not free it below */
1237 cancelled_mid[i] = true;
1241 if (!midQ[i]->resp_buf ||
1242 midQ[i]->mid_state != MID_RESPONSE_READY) {
1244 cifs_dbg(FYI, "Bad MID state?\n");
1248 buf = (char *)midQ[i]->resp_buf;
1249 resp_iov[i].iov_base = buf;
1250 resp_iov[i].iov_len = midQ[i]->resp_buf_size +
1251 HEADER_PREAMBLE_SIZE(server);
1253 if (midQ[i]->large_buf)
1254 resp_buf_type[i] = CIFS_LARGE_BUFFER;
1256 resp_buf_type[i] = CIFS_SMALL_BUFFER;
1258 rc = server->ops->check_receive(midQ[i], server,
1259 flags & CIFS_LOG_ERROR);
1261 /* mark it so buf will not be freed by delete_mid */
1262 if ((flags & CIFS_NO_RSP_BUF) == 0)
1263 midQ[i]->resp_buf = NULL;
1268 * Compounding is never used during session establish.
1270 spin_lock(&ses->ses_lock);
1271 if ((ses->ses_status == SES_NEW) || (optype & CIFS_NEG_OP) || (optype & CIFS_SESS_OP)) {
1273 .iov_base = resp_iov[0].iov_base,
1274 .iov_len = resp_iov[0].iov_len
1276 spin_unlock(&ses->ses_lock);
1277 cifs_server_lock(server);
1278 smb311_update_preauth_hash(ses, server, &iov, 1);
1279 cifs_server_unlock(server);
1280 spin_lock(&ses->ses_lock);
1282 spin_unlock(&ses->ses_lock);
1286 * This will dequeue all mids. After this it is important that the
1287 * demultiplex_thread will not process any of these mids any futher.
1288 * This is prevented above by using a noop callback that will not
1289 * wake this thread except for the very last PDU.
1291 for (i = 0; i < num_rqst; i++) {
1292 if (!cancelled_mid[i])
1293 delete_mid(midQ[i]);
1300 cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
1301 struct TCP_Server_Info *server,
1302 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
1303 struct kvec *resp_iov)
1305 return compound_send_recv(xid, ses, server, flags, 1,
1306 rqst, resp_buf_type, resp_iov);
1310 SendReceive2(const unsigned int xid, struct cifs_ses *ses,
1311 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
1312 const int flags, struct kvec *resp_iov)
1314 struct smb_rqst rqst;
1315 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
1318 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
1319 new_iov = kmalloc_array(n_vec + 1, sizeof(struct kvec),
1322 /* otherwise cifs_send_recv below sets resp_buf_type */
1323 *resp_buf_type = CIFS_NO_BUFFER;
1329 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1330 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
1332 new_iov[0].iov_base = new_iov[1].iov_base;
1333 new_iov[0].iov_len = 4;
1334 new_iov[1].iov_base += 4;
1335 new_iov[1].iov_len -= 4;
1337 memset(&rqst, 0, sizeof(struct smb_rqst));
1338 rqst.rq_iov = new_iov;
1339 rqst.rq_nvec = n_vec + 1;
1341 rc = cifs_send_recv(xid, ses, ses->server,
1342 &rqst, resp_buf_type, flags, resp_iov);
1343 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
1349 SendReceive(const unsigned int xid, struct cifs_ses *ses,
1350 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1351 int *pbytes_returned, const int flags)
1354 struct mid_q_entry *midQ;
1355 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1356 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1357 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1358 struct cifs_credits credits = { .value = 1, .instance = 0 };
1359 struct TCP_Server_Info *server;
1362 cifs_dbg(VFS, "Null smb session\n");
1365 server = ses->server;
1366 if (server == NULL) {
1367 cifs_dbg(VFS, "Null tcp session\n");
1371 spin_lock(&server->srv_lock);
1372 if (server->tcpStatus == CifsExiting) {
1373 spin_unlock(&server->srv_lock);
1376 spin_unlock(&server->srv_lock);
1378 /* Ensure that we do not send more than 50 overlapping requests
1379 to the same server. We may make this configurable later or
1382 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1383 cifs_server_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1388 rc = wait_for_free_request(server, flags, &credits.instance);
1392 /* make sure that we sign in the same order that we send on this socket
1393 and avoid races inside tcp sendmsg code that could cause corruption
1396 cifs_server_lock(server);
1398 rc = allocate_mid(ses, in_buf, &midQ);
1400 cifs_server_unlock(server);
1401 /* Update # of requests on wire to server */
1402 add_credits(server, &credits, 0);
1406 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1408 cifs_server_unlock(server);
1412 midQ->mid_state = MID_REQUEST_SUBMITTED;
1414 rc = smb_send(server, in_buf, len);
1415 cifs_save_when_sent(midQ);
1418 server->sequence_number -= 2;
1420 cifs_server_unlock(server);
1425 rc = wait_for_response(server, midQ);
1427 send_cancel(server, &rqst, midQ);
1428 spin_lock(&server->mid_lock);
1429 if (midQ->mid_state == MID_REQUEST_SUBMITTED ||
1430 midQ->mid_state == MID_RESPONSE_RECEIVED) {
1431 /* no longer considered to be "in-flight" */
1432 midQ->callback = release_mid;
1433 spin_unlock(&server->mid_lock);
1434 add_credits(server, &credits, 0);
1437 spin_unlock(&server->mid_lock);
1440 rc = cifs_sync_mid_result(midQ, server);
1442 add_credits(server, &credits, 0);
1446 if (!midQ->resp_buf || !out_buf ||
1447 midQ->mid_state != MID_RESPONSE_READY) {
1449 cifs_server_dbg(VFS, "Bad MID state?\n");
1453 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1454 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1455 rc = cifs_check_receive(midQ, server, 0);
1458 add_credits(server, &credits, 0);
1463 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1464 blocking lock to return. */
1467 send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1468 struct smb_hdr *in_buf,
1469 struct smb_hdr *out_buf)
1472 struct cifs_ses *ses = tcon->ses;
1473 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1475 /* We just modify the current in_buf to change
1476 the type of lock from LOCKING_ANDX_SHARED_LOCK
1477 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1478 LOCKING_ANDX_CANCEL_LOCK. */
1480 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1482 pSMB->hdr.Mid = get_next_mid(ses->server);
1484 return SendReceive(xid, ses, in_buf, out_buf,
1485 &bytes_returned, 0);
1489 SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1490 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1491 int *pbytes_returned)
1495 struct mid_q_entry *midQ;
1496 struct cifs_ses *ses;
1497 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1498 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1499 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1500 unsigned int instance;
1501 struct TCP_Server_Info *server;
1503 if (tcon == NULL || tcon->ses == NULL) {
1504 cifs_dbg(VFS, "Null smb session\n");
1508 server = ses->server;
1510 if (server == NULL) {
1511 cifs_dbg(VFS, "Null tcp session\n");
1515 spin_lock(&server->srv_lock);
1516 if (server->tcpStatus == CifsExiting) {
1517 spin_unlock(&server->srv_lock);
1520 spin_unlock(&server->srv_lock);
1522 /* Ensure that we do not send more than 50 overlapping requests
1523 to the same server. We may make this configurable later or
1526 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1527 cifs_tcon_dbg(VFS, "Invalid length, greater than maximum frame, %d\n",
1532 rc = wait_for_free_request(server, CIFS_BLOCKING_OP, &instance);
1536 /* make sure that we sign in the same order that we send on this socket
1537 and avoid races inside tcp sendmsg code that could cause corruption
1540 cifs_server_lock(server);
1542 rc = allocate_mid(ses, in_buf, &midQ);
1544 cifs_server_unlock(server);
1548 rc = cifs_sign_smb(in_buf, server, &midQ->sequence_number);
1551 cifs_server_unlock(server);
1555 midQ->mid_state = MID_REQUEST_SUBMITTED;
1556 rc = smb_send(server, in_buf, len);
1557 cifs_save_when_sent(midQ);
1560 server->sequence_number -= 2;
1562 cifs_server_unlock(server);
1569 /* Wait for a reply - allow signals to interrupt. */
1570 rc = wait_event_interruptible(server->response_q,
1571 (!(midQ->mid_state == MID_REQUEST_SUBMITTED ||
1572 midQ->mid_state == MID_RESPONSE_RECEIVED)) ||
1573 ((server->tcpStatus != CifsGood) &&
1574 (server->tcpStatus != CifsNew)));
1576 /* Were we interrupted by a signal ? */
1577 spin_lock(&server->srv_lock);
1578 if ((rc == -ERESTARTSYS) &&
1579 (midQ->mid_state == MID_REQUEST_SUBMITTED ||
1580 midQ->mid_state == MID_RESPONSE_RECEIVED) &&
1581 ((server->tcpStatus == CifsGood) ||
1582 (server->tcpStatus == CifsNew))) {
1583 spin_unlock(&server->srv_lock);
1585 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1586 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1587 blocking lock to return. */
1588 rc = send_cancel(server, &rqst, midQ);
1594 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1595 to cause the blocking lock to return. */
1597 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1599 /* If we get -ENOLCK back the lock may have
1600 already been removed. Don't exit in this case. */
1601 if (rc && rc != -ENOLCK) {
1607 rc = wait_for_response(server, midQ);
1609 send_cancel(server, &rqst, midQ);
1610 spin_lock(&server->mid_lock);
1611 if (midQ->mid_state == MID_REQUEST_SUBMITTED ||
1612 midQ->mid_state == MID_RESPONSE_RECEIVED) {
1613 /* no longer considered to be "in-flight" */
1614 midQ->callback = release_mid;
1615 spin_unlock(&server->mid_lock);
1618 spin_unlock(&server->mid_lock);
1621 /* We got the response - restart system call. */
1623 spin_lock(&server->srv_lock);
1625 spin_unlock(&server->srv_lock);
1627 rc = cifs_sync_mid_result(midQ, server);
1631 /* rcvd frame is ok */
1632 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_READY) {
1634 cifs_tcon_dbg(VFS, "Bad MID state?\n");
1638 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1639 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1640 rc = cifs_check_receive(midQ, server, 0);
1643 if (rstart && rc == -EACCES)
1644 return -ERESTARTSYS;
1649 * Discard any remaining data in the current SMB. To do this, we borrow the
1653 cifs_discard_remaining_data(struct TCP_Server_Info *server)
1655 unsigned int rfclen = server->pdu_size;
1656 size_t remaining = rfclen + HEADER_PREAMBLE_SIZE(server) -
1659 while (remaining > 0) {
1662 length = cifs_discard_from_socket(server,
1663 min_t(size_t, remaining,
1664 CIFSMaxBufSize + MAX_HEADER_SIZE(server)));
1667 server->total_read += length;
1668 remaining -= length;
1675 __cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid,
1680 length = cifs_discard_remaining_data(server);
1681 dequeue_mid(mid, malformed);
1682 mid->resp_buf = server->smallbuf;
1683 server->smallbuf = NULL;
1688 cifs_readv_discard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1690 struct cifs_readdata *rdata = mid->callback_data;
1692 return __cifs_readv_discard(server, mid, rdata->result);
1696 cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1699 unsigned int data_offset, data_len;
1700 struct cifs_readdata *rdata = mid->callback_data;
1701 char *buf = server->smallbuf;
1702 unsigned int buflen = server->pdu_size + HEADER_PREAMBLE_SIZE(server);
1703 bool use_rdma_mr = false;
1705 cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
1706 __func__, mid->mid, rdata->offset, rdata->bytes);
1709 * read the rest of READ_RSP header (sans Data array), or whatever we
1710 * can if there's not enough data. At this point, we've read down to
1713 len = min_t(unsigned int, buflen, server->vals->read_rsp_size) -
1714 HEADER_SIZE(server) + 1;
1716 length = cifs_read_from_socket(server,
1717 buf + HEADER_SIZE(server) - 1, len);
1720 server->total_read += length;
1722 if (server->ops->is_session_expired &&
1723 server->ops->is_session_expired(buf)) {
1724 cifs_reconnect(server, true);
1728 if (server->ops->is_status_pending &&
1729 server->ops->is_status_pending(buf, server)) {
1730 cifs_discard_remaining_data(server);
1734 /* set up first two iov for signature check and to get credits */
1735 rdata->iov[0].iov_base = buf;
1736 rdata->iov[0].iov_len = HEADER_PREAMBLE_SIZE(server);
1737 rdata->iov[1].iov_base = buf + HEADER_PREAMBLE_SIZE(server);
1738 rdata->iov[1].iov_len =
1739 server->total_read - HEADER_PREAMBLE_SIZE(server);
1740 cifs_dbg(FYI, "0: iov_base=%p iov_len=%zu\n",
1741 rdata->iov[0].iov_base, rdata->iov[0].iov_len);
1742 cifs_dbg(FYI, "1: iov_base=%p iov_len=%zu\n",
1743 rdata->iov[1].iov_base, rdata->iov[1].iov_len);
1745 /* Was the SMB read successful? */
1746 rdata->result = server->ops->map_error(buf, false);
1747 if (rdata->result != 0) {
1748 cifs_dbg(FYI, "%s: server returned error %d\n",
1749 __func__, rdata->result);
1750 /* normal error on read response */
1751 return __cifs_readv_discard(server, mid, false);
1754 /* Is there enough to get to the rest of the READ_RSP header? */
1755 if (server->total_read < server->vals->read_rsp_size) {
1756 cifs_dbg(FYI, "%s: server returned short header. got=%u expected=%zu\n",
1757 __func__, server->total_read,
1758 server->vals->read_rsp_size);
1759 rdata->result = -EIO;
1760 return cifs_readv_discard(server, mid);
1763 data_offset = server->ops->read_data_offset(buf) +
1764 HEADER_PREAMBLE_SIZE(server);
1765 if (data_offset < server->total_read) {
1767 * win2k8 sometimes sends an offset of 0 when the read
1768 * is beyond the EOF. Treat it as if the data starts just after
1771 cifs_dbg(FYI, "%s: data offset (%u) inside read response header\n",
1772 __func__, data_offset);
1773 data_offset = server->total_read;
1774 } else if (data_offset > MAX_CIFS_SMALL_BUFFER_SIZE) {
1775 /* data_offset is beyond the end of smallbuf */
1776 cifs_dbg(FYI, "%s: data offset (%u) beyond end of smallbuf\n",
1777 __func__, data_offset);
1778 rdata->result = -EIO;
1779 return cifs_readv_discard(server, mid);
1782 cifs_dbg(FYI, "%s: total_read=%u data_offset=%u\n",
1783 __func__, server->total_read, data_offset);
1785 len = data_offset - server->total_read;
1787 /* read any junk before data into the rest of smallbuf */
1788 length = cifs_read_from_socket(server,
1789 buf + server->total_read, len);
1792 server->total_read += length;
1795 /* how much data is in the response? */
1796 #ifdef CONFIG_CIFS_SMB_DIRECT
1797 use_rdma_mr = rdata->mr;
1799 data_len = server->ops->read_data_length(buf, use_rdma_mr);
1800 if (!use_rdma_mr && (data_offset + data_len > buflen)) {
1801 /* data_len is corrupt -- discard frame */
1802 rdata->result = -EIO;
1803 return cifs_readv_discard(server, mid);
1806 #ifdef CONFIG_CIFS_SMB_DIRECT
1808 length = data_len; /* An RDMA read is already done. */
1811 length = cifs_read_iter_from_socket(server, &rdata->iter,
1814 rdata->got_bytes += length;
1815 server->total_read += length;
1817 cifs_dbg(FYI, "total_read=%u buflen=%u remaining=%u\n",
1818 server->total_read, buflen, data_len);
1820 /* discard anything left over */
1821 if (server->total_read < buflen)
1822 return cifs_readv_discard(server, mid);
1824 dequeue_mid(mid, false);
1825 mid->resp_buf = server->smallbuf;
1826 server->smallbuf = NULL;