4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 * Jeremy Allison (jra@samba.org) 2006.
8 * This library is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU Lesser General Public License as published
10 * by the Free Software Foundation; either version 2.1 of the License, or
11 * (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
16 * the GNU Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public License
19 * along with this library; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24 #include <linux/list.h>
25 #include <linux/gfp.h>
26 #include <linux/wait.h>
27 #include <linux/net.h>
28 #include <linux/delay.h>
29 #include <linux/freezer.h>
30 #include <linux/tcp.h>
31 #include <linux/bvec.h>
32 #include <linux/highmem.h>
33 #include <linux/uaccess.h>
34 #include <asm/processor.h>
35 #include <linux/mempool.h>
36 #include <linux/sched/signal.h>
39 #include "cifsproto.h"
40 #include "cifs_debug.h"
41 #include "smb2proto.h"
42 #include "smbdirect.h"
44 /* Max number of iovectors we can use off the stack when sending requests. */
45 #define CIFS_MAX_IOV_SIZE 8
48 cifs_wake_up_task(struct mid_q_entry
*mid
)
50 wake_up_process(mid
->callback_data
);
54 AllocMidQEntry(const struct smb_hdr
*smb_buffer
, struct TCP_Server_Info
*server
)
56 struct mid_q_entry
*temp
;
59 cifs_dbg(VFS
, "Null TCP session in AllocMidQEntry\n");
63 temp
= mempool_alloc(cifs_mid_poolp
, GFP_NOFS
);
64 memset(temp
, 0, sizeof(struct mid_q_entry
));
65 kref_init(&temp
->refcount
);
66 temp
->mid
= get_mid(smb_buffer
);
67 temp
->pid
= current
->pid
;
68 temp
->command
= cpu_to_le16(smb_buffer
->Command
);
69 cifs_dbg(FYI
, "For smb_command %d\n", smb_buffer
->Command
);
70 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
71 /* when mid allocated can be before when sent */
72 temp
->when_alloc
= jiffies
;
73 temp
->server
= server
;
76 * The default is for the mid to be synchronous, so the
77 * default callback just wakes up the current task.
79 get_task_struct(current
);
80 temp
->creator
= current
;
81 temp
->callback
= cifs_wake_up_task
;
82 temp
->callback_data
= current
;
84 atomic_inc(&midCount
);
85 temp
->mid_state
= MID_REQUEST_ALLOCATED
;
89 static void _cifs_mid_q_entry_release(struct kref
*refcount
)
91 struct mid_q_entry
*midEntry
=
92 container_of(refcount
, struct mid_q_entry
, refcount
);
93 #ifdef CONFIG_CIFS_STATS2
94 __le16 command
= midEntry
->server
->vals
->lock_cmd
;
95 __u16 smb_cmd
= le16_to_cpu(midEntry
->command
);
97 unsigned long roundtrip_time
;
99 struct TCP_Server_Info
*server
= midEntry
->server
;
101 if (midEntry
->resp_buf
&& (midEntry
->mid_flags
& MID_WAIT_CANCELLED
) &&
102 midEntry
->mid_state
== MID_RESPONSE_RECEIVED
&&
103 server
->ops
->handle_cancelled_mid
)
104 server
->ops
->handle_cancelled_mid(midEntry
->resp_buf
, server
);
106 midEntry
->mid_state
= MID_FREE
;
107 atomic_dec(&midCount
);
108 if (midEntry
->large_buf
)
109 cifs_buf_release(midEntry
->resp_buf
);
111 cifs_small_buf_release(midEntry
->resp_buf
);
112 #ifdef CONFIG_CIFS_STATS2
114 if (now
< midEntry
->when_alloc
)
115 cifs_server_dbg(VFS
, "Invalid mid allocation time\n");
116 roundtrip_time
= now
- midEntry
->when_alloc
;
118 if (smb_cmd
< NUMBER_OF_SMB2_COMMANDS
) {
119 if (atomic_read(&server
->num_cmds
[smb_cmd
]) == 0) {
120 server
->slowest_cmd
[smb_cmd
] = roundtrip_time
;
121 server
->fastest_cmd
[smb_cmd
] = roundtrip_time
;
123 if (server
->slowest_cmd
[smb_cmd
] < roundtrip_time
)
124 server
->slowest_cmd
[smb_cmd
] = roundtrip_time
;
125 else if (server
->fastest_cmd
[smb_cmd
] > roundtrip_time
)
126 server
->fastest_cmd
[smb_cmd
] = roundtrip_time
;
128 cifs_stats_inc(&server
->num_cmds
[smb_cmd
]);
129 server
->time_per_cmd
[smb_cmd
] += roundtrip_time
;
132 * commands taking longer than one second (default) can be indications
133 * that something is wrong, unless it is quite a slow link or a very
134 * busy server. Note that this calc is unlikely or impossible to wrap
135 * as long as slow_rsp_threshold is not set way above recommended max
136 * value (32767 ie 9 hours) and is generally harmless even if wrong
137 * since only affects debug counters - so leaving the calc as simple
138 * comparison rather than doing multiple conversions and overflow
141 if ((slow_rsp_threshold
!= 0) &&
142 time_after(now
, midEntry
->when_alloc
+ (slow_rsp_threshold
* HZ
)) &&
143 (midEntry
->command
!= command
)) {
145 * smb2slowcmd[NUMBER_OF_SMB2_COMMANDS] counts by command
146 * NB: le16_to_cpu returns unsigned so can not be negative below
148 if (smb_cmd
< NUMBER_OF_SMB2_COMMANDS
)
149 cifs_stats_inc(&server
->smb2slowcmd
[smb_cmd
]);
151 trace_smb3_slow_rsp(smb_cmd
, midEntry
->mid
, midEntry
->pid
,
152 midEntry
->when_sent
, midEntry
->when_received
);
153 if (cifsFYI
& CIFS_TIMER
) {
154 pr_debug("slow rsp: cmd %d mid %llu",
155 midEntry
->command
, midEntry
->mid
);
156 cifs_info("A: 0x%lx S: 0x%lx R: 0x%lx\n",
157 now
- midEntry
->when_alloc
,
158 now
- midEntry
->when_sent
,
159 now
- midEntry
->when_received
);
163 put_task_struct(midEntry
->creator
);
165 mempool_free(midEntry
, cifs_mid_poolp
);
168 void cifs_mid_q_entry_release(struct mid_q_entry
*midEntry
)
170 spin_lock(&GlobalMid_Lock
);
171 kref_put(&midEntry
->refcount
, _cifs_mid_q_entry_release
);
172 spin_unlock(&GlobalMid_Lock
);
175 void DeleteMidQEntry(struct mid_q_entry
*midEntry
)
177 cifs_mid_q_entry_release(midEntry
);
181 cifs_delete_mid(struct mid_q_entry
*mid
)
183 spin_lock(&GlobalMid_Lock
);
184 if (!(mid
->mid_flags
& MID_DELETED
)) {
185 list_del_init(&mid
->qhead
);
186 mid
->mid_flags
|= MID_DELETED
;
188 spin_unlock(&GlobalMid_Lock
);
190 DeleteMidQEntry(mid
);
194 * smb_send_kvec - send an array of kvecs to the server
195 * @server: Server to send the data to
196 * @smb_msg: Message to send
197 * @sent: amount of data sent on socket is stored here
199 * Our basic "send data to server" function. Should be called with srv_mutex
200 * held. The caller is responsible for handling the results.
203 smb_send_kvec(struct TCP_Server_Info
*server
, struct msghdr
*smb_msg
,
208 struct socket
*ssocket
= server
->ssocket
;
212 smb_msg
->msg_name
= (struct sockaddr
*) &server
->dstaddr
;
213 smb_msg
->msg_namelen
= sizeof(struct sockaddr
);
214 smb_msg
->msg_control
= NULL
;
215 smb_msg
->msg_controllen
= 0;
216 if (server
->noblocksnd
)
217 smb_msg
->msg_flags
= MSG_DONTWAIT
+ MSG_NOSIGNAL
;
219 smb_msg
->msg_flags
= MSG_NOSIGNAL
;
221 while (msg_data_left(smb_msg
)) {
223 * If blocking send, we try 3 times, since each can block
224 * for 5 seconds. For nonblocking we have to try more
225 * but wait increasing amounts of time allowing time for
226 * socket to clear. The overall time we wait in either
227 * case to send on the socket is about 15 seconds.
228 * Similarly we wait for 15 seconds for a response from
229 * the server in SendReceive[2] for the server to send
230 * a response back for most types of requests (except
231 * SMB Write past end of file which can be slow, and
232 * blocking lock operations). NFS waits slightly longer
233 * than CIFS, but this can make it take longer for
234 * nonresponsive servers to be detected and 15 seconds
235 * is more than enough time for modern networks to
236 * send a packet. In most cases if we fail to send
237 * after the retries we will kill the socket and
238 * reconnect which may clear the network problem.
240 rc
= sock_sendmsg(ssocket
, smb_msg
);
244 (!server
->noblocksnd
&& (retries
> 2))) {
245 cifs_server_dbg(VFS
, "sends on sock %p stuck for 15 seconds\n",
249 msleep(1 << retries
);
257 /* should never happen, letting socket clear before
258 retrying is our only obvious option here */
259 cifs_server_dbg(VFS
, "tcp sent no data\n");
264 /* send was at least partially successful */
266 retries
= 0; /* in case we get ENOSPC on the next send */
272 smb_rqst_len(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
)
277 unsigned long buflen
= 0;
279 if (server
->vals
->header_preamble_size
== 0 &&
280 rqst
->rq_nvec
>= 2 && rqst
->rq_iov
[0].iov_len
== 4) {
281 iov
= &rqst
->rq_iov
[1];
282 nvec
= rqst
->rq_nvec
- 1;
285 nvec
= rqst
->rq_nvec
;
288 /* total up iov array first */
289 for (i
= 0; i
< nvec
; i
++)
290 buflen
+= iov
[i
].iov_len
;
293 * Add in the page array if there is one. The caller needs to make
294 * sure rq_offset and rq_tailsz are set correctly. If a buffer of
295 * multiple pages ends at page boundary, rq_tailsz needs to be set to
298 if (rqst
->rq_npages
) {
299 if (rqst
->rq_npages
== 1)
300 buflen
+= rqst
->rq_tailsz
;
303 * If there is more than one page, calculate the
304 * buffer length based on rq_offset and rq_tailsz
306 buflen
+= rqst
->rq_pagesz
* (rqst
->rq_npages
- 1) -
308 buflen
+= rqst
->rq_tailsz
;
316 __smb_send_rqst(struct TCP_Server_Info
*server
, int num_rqst
,
317 struct smb_rqst
*rqst
)
322 unsigned int send_length
= 0;
324 sigset_t mask
, oldmask
;
325 size_t total_len
= 0, sent
, size
;
326 struct socket
*ssocket
= server
->ssocket
;
327 struct msghdr smb_msg
;
328 __be32 rfc1002_marker
;
330 if (cifs_rdma_enabled(server
)) {
331 /* return -EAGAIN when connecting or reconnecting */
333 if (server
->smbd_conn
)
334 rc
= smbd_send(server
, num_rqst
, rqst
);
341 if (signal_pending(current
)) {
342 cifs_dbg(FYI
, "signal is pending before sending any data\n");
346 /* cork the socket */
347 tcp_sock_set_cork(ssocket
->sk
, true);
349 for (j
= 0; j
< num_rqst
; j
++)
350 send_length
+= smb_rqst_len(server
, &rqst
[j
]);
351 rfc1002_marker
= cpu_to_be32(send_length
);
354 * We should not allow signals to interrupt the network send because
355 * any partial send will cause session reconnects thus increasing
356 * latency of system calls and overload a server with unnecessary
361 sigprocmask(SIG_BLOCK
, &mask
, &oldmask
);
363 /* Generate a rfc1002 marker for SMB2+ */
364 if (server
->vals
->header_preamble_size
== 0) {
366 .iov_base
= &rfc1002_marker
,
369 iov_iter_kvec(&smb_msg
.msg_iter
, WRITE
, &hiov
, 1, 4);
370 rc
= smb_send_kvec(server
, &smb_msg
, &sent
);
378 cifs_dbg(FYI
, "Sending smb: smb_len=%u\n", send_length
);
380 for (j
= 0; j
< num_rqst
; j
++) {
381 iov
= rqst
[j
].rq_iov
;
382 n_vec
= rqst
[j
].rq_nvec
;
385 for (i
= 0; i
< n_vec
; i
++) {
386 dump_smb(iov
[i
].iov_base
, iov
[i
].iov_len
);
387 size
+= iov
[i
].iov_len
;
390 iov_iter_kvec(&smb_msg
.msg_iter
, WRITE
, iov
, n_vec
, size
);
392 rc
= smb_send_kvec(server
, &smb_msg
, &sent
);
398 /* now walk the page array and send each page in it */
399 for (i
= 0; i
< rqst
[j
].rq_npages
; i
++) {
402 bvec
.bv_page
= rqst
[j
].rq_pages
[i
];
403 rqst_page_get_length(&rqst
[j
], i
, &bvec
.bv_len
,
406 iov_iter_bvec(&smb_msg
.msg_iter
, WRITE
,
407 &bvec
, 1, bvec
.bv_len
);
408 rc
= smb_send_kvec(server
, &smb_msg
, &sent
);
417 sigprocmask(SIG_SETMASK
, &oldmask
, NULL
);
420 * If signal is pending but we have already sent the whole packet to
421 * the server we need to return success status to allow a corresponding
422 * mid entry to be kept in the pending requests queue thus allowing
423 * to handle responses from the server by the client.
425 * If only part of the packet has been sent there is no need to hide
426 * interrupt because the session will be reconnected anyway, so there
427 * won't be any response from the server to handle.
430 if (signal_pending(current
) && (total_len
!= send_length
)) {
431 cifs_dbg(FYI
, "signal is pending after attempt to send\n");
436 tcp_sock_set_cork(ssocket
->sk
, false);
438 if ((total_len
> 0) && (total_len
!= send_length
)) {
439 cifs_dbg(FYI
, "partial send (wanted=%u sent=%zu): terminating session\n",
440 send_length
, total_len
);
442 * If we have only sent part of an SMB then the next SMB could
443 * be taken as the remainder of this one. We need to kill the
444 * socket so the server throws away the partial SMB
446 server
->tcpStatus
= CifsNeedReconnect
;
447 trace_smb3_partial_send_reconnect(server
->CurrentMid
,
451 if (rc
< 0 && rc
!= -EINTR
)
452 cifs_server_dbg(VFS
, "Error %d sending data on socket to server\n",
461 smb_send_rqst(struct TCP_Server_Info
*server
, int num_rqst
,
462 struct smb_rqst
*rqst
, int flags
)
465 struct smb2_transform_hdr
*tr_hdr
;
466 struct smb_rqst cur_rqst
[MAX_COMPOUND
];
469 if (!(flags
& CIFS_TRANSFORM_REQ
))
470 return __smb_send_rqst(server
, num_rqst
, rqst
);
472 if (num_rqst
> MAX_COMPOUND
- 1)
475 if (!server
->ops
->init_transform_rq
) {
476 cifs_server_dbg(VFS
, "Encryption requested but transform callback is missing\n");
480 tr_hdr
= kmalloc(sizeof(*tr_hdr
), GFP_NOFS
);
484 memset(&cur_rqst
[0], 0, sizeof(cur_rqst
));
485 memset(&iov
, 0, sizeof(iov
));
486 memset(tr_hdr
, 0, sizeof(*tr_hdr
));
488 iov
.iov_base
= tr_hdr
;
489 iov
.iov_len
= sizeof(*tr_hdr
);
490 cur_rqst
[0].rq_iov
= &iov
;
491 cur_rqst
[0].rq_nvec
= 1;
493 rc
= server
->ops
->init_transform_rq(server
, num_rqst
+ 1,
498 rc
= __smb_send_rqst(server
, num_rqst
+ 1, &cur_rqst
[0]);
499 smb3_free_compound_rqst(num_rqst
, &cur_rqst
[1]);
506 smb_send(struct TCP_Server_Info
*server
, struct smb_hdr
*smb_buffer
,
507 unsigned int smb_buf_length
)
510 struct smb_rqst rqst
= { .rq_iov
= iov
,
513 iov
[0].iov_base
= smb_buffer
;
515 iov
[1].iov_base
= (char *)smb_buffer
+ 4;
516 iov
[1].iov_len
= smb_buf_length
;
518 return __smb_send_rqst(server
, 1, &rqst
);
522 wait_for_free_credits(struct TCP_Server_Info
*server
, const int num_credits
,
523 const int timeout
, const int flags
,
524 unsigned int *instance
)
532 t
= MAX_JIFFY_OFFSET
;
534 t
= msecs_to_jiffies(timeout
);
536 optype
= flags
& CIFS_OP_MASK
;
540 credits
= server
->ops
->get_credits_field(server
, optype
);
541 /* Since an echo is already inflight, no need to wait to send another */
542 if (*credits
<= 0 && optype
== CIFS_ECHO_OP
)
545 spin_lock(&server
->req_lock
);
546 if ((flags
& CIFS_TIMEOUT_MASK
) == CIFS_NON_BLOCKING
) {
547 /* oplock breaks must not be held up */
549 if (server
->in_flight
> server
->max_in_flight
)
550 server
->max_in_flight
= server
->in_flight
;
552 *instance
= server
->reconnect_instance
;
553 spin_unlock(&server
->req_lock
);
558 if (*credits
< num_credits
) {
559 spin_unlock(&server
->req_lock
);
560 cifs_num_waiters_inc(server
);
561 rc
= wait_event_killable_timeout(server
->request_q
,
562 has_credits(server
, credits
, num_credits
), t
);
563 cifs_num_waiters_dec(server
);
565 trace_smb3_credit_timeout(server
->CurrentMid
,
566 server
->hostname
, num_credits
);
567 cifs_server_dbg(VFS
, "wait timed out after %d ms\n",
571 if (rc
== -ERESTARTSYS
)
573 spin_lock(&server
->req_lock
);
575 if (server
->tcpStatus
== CifsExiting
) {
576 spin_unlock(&server
->req_lock
);
581 * For normal commands, reserve the last MAX_COMPOUND
582 * credits to compound requests.
583 * Otherwise these compounds could be permanently
584 * starved for credits by single-credit requests.
586 * To prevent spinning CPU, block this thread until
587 * there are >MAX_COMPOUND credits available.
588 * But only do this is we already have a lot of
589 * credits in flight to avoid triggering this check
590 * for servers that are slow to hand out credits on
593 if (!optype
&& num_credits
== 1 &&
594 server
->in_flight
> 2 * MAX_COMPOUND
&&
595 *credits
<= MAX_COMPOUND
) {
596 spin_unlock(&server
->req_lock
);
597 cifs_num_waiters_inc(server
);
598 rc
= wait_event_killable_timeout(
600 has_credits(server
, credits
,
603 cifs_num_waiters_dec(server
);
605 trace_smb3_credit_timeout(
607 server
->hostname
, num_credits
);
608 cifs_server_dbg(VFS
, "wait timed out after %d ms\n",
612 if (rc
== -ERESTARTSYS
)
614 spin_lock(&server
->req_lock
);
619 * Can not count locking commands against total
620 * as they are allowed to block on server.
623 /* update # of requests on the wire to server */
624 if ((flags
& CIFS_TIMEOUT_MASK
) != CIFS_BLOCKING_OP
) {
625 *credits
-= num_credits
;
626 server
->in_flight
+= num_credits
;
627 if (server
->in_flight
> server
->max_in_flight
)
628 server
->max_in_flight
= server
->in_flight
;
629 *instance
= server
->reconnect_instance
;
631 spin_unlock(&server
->req_lock
);
639 wait_for_free_request(struct TCP_Server_Info
*server
, const int flags
,
640 unsigned int *instance
)
642 return wait_for_free_credits(server
, 1, -1, flags
,
647 wait_for_compound_request(struct TCP_Server_Info
*server
, int num
,
648 const int flags
, unsigned int *instance
)
652 credits
= server
->ops
->get_credits_field(server
, flags
& CIFS_OP_MASK
);
654 spin_lock(&server
->req_lock
);
655 if (*credits
< num
) {
657 * Return immediately if not too many requests in flight since
658 * we will likely be stuck on waiting for credits.
660 if (server
->in_flight
< num
- *credits
) {
661 spin_unlock(&server
->req_lock
);
665 spin_unlock(&server
->req_lock
);
667 return wait_for_free_credits(server
, num
, 60000, flags
,
672 cifs_wait_mtu_credits(struct TCP_Server_Info
*server
, unsigned int size
,
673 unsigned int *num
, struct cifs_credits
*credits
)
677 credits
->instance
= server
->reconnect_instance
;
681 static int allocate_mid(struct cifs_ses
*ses
, struct smb_hdr
*in_buf
,
682 struct mid_q_entry
**ppmidQ
)
684 if (ses
->server
->tcpStatus
== CifsExiting
) {
688 if (ses
->server
->tcpStatus
== CifsNeedReconnect
) {
689 cifs_dbg(FYI
, "tcp session dead - return to caller to retry\n");
693 if (ses
->status
== CifsNew
) {
694 if ((in_buf
->Command
!= SMB_COM_SESSION_SETUP_ANDX
) &&
695 (in_buf
->Command
!= SMB_COM_NEGOTIATE
))
697 /* else ok - we are setting up session */
700 if (ses
->status
== CifsExiting
) {
701 /* check if SMB session is bad because we are setting it up */
702 if (in_buf
->Command
!= SMB_COM_LOGOFF_ANDX
)
704 /* else ok - we are shutting down session */
707 *ppmidQ
= AllocMidQEntry(in_buf
, ses
->server
);
710 spin_lock(&GlobalMid_Lock
);
711 list_add_tail(&(*ppmidQ
)->qhead
, &ses
->server
->pending_mid_q
);
712 spin_unlock(&GlobalMid_Lock
);
717 wait_for_response(struct TCP_Server_Info
*server
, struct mid_q_entry
*midQ
)
721 error
= wait_event_freezekillable_unsafe(server
->response_q
,
722 midQ
->mid_state
!= MID_REQUEST_SUBMITTED
);
730 cifs_setup_async_request(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
)
733 struct smb_hdr
*hdr
= (struct smb_hdr
*)rqst
->rq_iov
[0].iov_base
;
734 struct mid_q_entry
*mid
;
736 if (rqst
->rq_iov
[0].iov_len
!= 4 ||
737 rqst
->rq_iov
[0].iov_base
+ 4 != rqst
->rq_iov
[1].iov_base
)
738 return ERR_PTR(-EIO
);
740 /* enable signing if server requires it */
742 hdr
->Flags2
|= SMBFLG2_SECURITY_SIGNATURE
;
744 mid
= AllocMidQEntry(hdr
, server
);
746 return ERR_PTR(-ENOMEM
);
748 rc
= cifs_sign_rqst(rqst
, server
, &mid
->sequence_number
);
750 DeleteMidQEntry(mid
);
758 * Send a SMB request and set the callback function in the mid to handle
759 * the result. Caller is responsible for dealing with timeouts.
762 cifs_call_async(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
,
763 mid_receive_t
*receive
, mid_callback_t
*callback
,
764 mid_handle_t
*handle
, void *cbdata
, const int flags
,
765 const struct cifs_credits
*exist_credits
)
768 struct mid_q_entry
*mid
;
769 struct cifs_credits credits
= { .value
= 0, .instance
= 0 };
770 unsigned int instance
;
773 optype
= flags
& CIFS_OP_MASK
;
775 if ((flags
& CIFS_HAS_CREDITS
) == 0) {
776 rc
= wait_for_free_request(server
, flags
, &instance
);
780 credits
.instance
= instance
;
782 instance
= exist_credits
->instance
;
784 mutex_lock(&server
->srv_mutex
);
787 * We can't use credits obtained from the previous session to send this
788 * request. Check if there were reconnects after we obtained credits and
789 * return -EAGAIN in such cases to let callers handle it.
791 if (instance
!= server
->reconnect_instance
) {
792 mutex_unlock(&server
->srv_mutex
);
793 add_credits_and_wake_if(server
, &credits
, optype
);
797 mid
= server
->ops
->setup_async_request(server
, rqst
);
799 mutex_unlock(&server
->srv_mutex
);
800 add_credits_and_wake_if(server
, &credits
, optype
);
804 mid
->receive
= receive
;
805 mid
->callback
= callback
;
806 mid
->callback_data
= cbdata
;
807 mid
->handle
= handle
;
808 mid
->mid_state
= MID_REQUEST_SUBMITTED
;
810 /* put it on the pending_mid_q */
811 spin_lock(&GlobalMid_Lock
);
812 list_add_tail(&mid
->qhead
, &server
->pending_mid_q
);
813 spin_unlock(&GlobalMid_Lock
);
816 * Need to store the time in mid before calling I/O. For call_async,
817 * I/O response may come back and free the mid entry on another thread.
819 cifs_save_when_sent(mid
);
820 cifs_in_send_inc(server
);
821 rc
= smb_send_rqst(server
, 1, rqst
, flags
);
822 cifs_in_send_dec(server
);
825 revert_current_mid(server
, mid
->credits
);
826 server
->sequence_number
-= 2;
827 cifs_delete_mid(mid
);
830 mutex_unlock(&server
->srv_mutex
);
835 add_credits_and_wake_if(server
, &credits
, optype
);
841 * Send an SMB Request. No response info (other than return code)
842 * needs to be parsed.
844 * flags indicate the type of request buffer and how long to wait
845 * and whether to log NT STATUS code (error) before mapping it to POSIX error
849 SendReceiveNoRsp(const unsigned int xid
, struct cifs_ses
*ses
,
850 char *in_buf
, int flags
)
857 iov
[0].iov_base
= in_buf
;
858 iov
[0].iov_len
= get_rfc1002_length(in_buf
) + 4;
859 flags
|= CIFS_NO_RSP_BUF
;
860 rc
= SendReceive2(xid
, ses
, iov
, 1, &resp_buf_type
, flags
, &rsp_iov
);
861 cifs_dbg(NOISY
, "SendRcvNoRsp flags %d rc %d\n", flags
, rc
);
867 cifs_sync_mid_result(struct mid_q_entry
*mid
, struct TCP_Server_Info
*server
)
871 cifs_dbg(FYI
, "%s: cmd=%d mid=%llu state=%d\n",
872 __func__
, le16_to_cpu(mid
->command
), mid
->mid
, mid
->mid_state
);
874 spin_lock(&GlobalMid_Lock
);
875 switch (mid
->mid_state
) {
876 case MID_RESPONSE_RECEIVED
:
877 spin_unlock(&GlobalMid_Lock
);
879 case MID_RETRY_NEEDED
:
882 case MID_RESPONSE_MALFORMED
:
889 if (!(mid
->mid_flags
& MID_DELETED
)) {
890 list_del_init(&mid
->qhead
);
891 mid
->mid_flags
|= MID_DELETED
;
893 cifs_server_dbg(VFS
, "%s: invalid mid state mid=%llu state=%d\n",
894 __func__
, mid
->mid
, mid
->mid_state
);
897 spin_unlock(&GlobalMid_Lock
);
899 DeleteMidQEntry(mid
);
904 send_cancel(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
,
905 struct mid_q_entry
*mid
)
907 return server
->ops
->send_cancel
?
908 server
->ops
->send_cancel(server
, rqst
, mid
) : 0;
912 cifs_check_receive(struct mid_q_entry
*mid
, struct TCP_Server_Info
*server
,
915 unsigned int len
= get_rfc1002_length(mid
->resp_buf
) + 4;
917 dump_smb(mid
->resp_buf
, min_t(u32
, 92, len
));
919 /* convert the length into a more usable form */
923 struct smb_rqst rqst
= { .rq_iov
= iov
,
926 iov
[0].iov_base
= mid
->resp_buf
;
928 iov
[1].iov_base
= (char *)mid
->resp_buf
+ 4;
929 iov
[1].iov_len
= len
- 4;
930 /* FIXME: add code to kill session */
931 rc
= cifs_verify_signature(&rqst
, server
,
932 mid
->sequence_number
);
934 cifs_server_dbg(VFS
, "SMB signature verification returned error = %d\n",
938 /* BB special case reconnect tid and uid here? */
939 return map_smb_to_linux_error(mid
->resp_buf
, log_error
);
943 cifs_setup_request(struct cifs_ses
*ses
, struct TCP_Server_Info
*ignored
,
944 struct smb_rqst
*rqst
)
947 struct smb_hdr
*hdr
= (struct smb_hdr
*)rqst
->rq_iov
[0].iov_base
;
948 struct mid_q_entry
*mid
;
950 if (rqst
->rq_iov
[0].iov_len
!= 4 ||
951 rqst
->rq_iov
[0].iov_base
+ 4 != rqst
->rq_iov
[1].iov_base
)
952 return ERR_PTR(-EIO
);
954 rc
= allocate_mid(ses
, hdr
, &mid
);
957 rc
= cifs_sign_rqst(rqst
, ses
->server
, &mid
->sequence_number
);
959 cifs_delete_mid(mid
);
966 cifs_compound_callback(struct mid_q_entry
*mid
)
968 struct TCP_Server_Info
*server
= mid
->server
;
969 struct cifs_credits credits
;
971 credits
.value
= server
->ops
->get_credits(mid
);
972 credits
.instance
= server
->reconnect_instance
;
974 add_credits(server
, &credits
, mid
->optype
);
978 cifs_compound_last_callback(struct mid_q_entry
*mid
)
980 cifs_compound_callback(mid
);
981 cifs_wake_up_task(mid
);
985 cifs_cancelled_callback(struct mid_q_entry
*mid
)
987 cifs_compound_callback(mid
);
988 DeleteMidQEntry(mid
);
992 * Return a channel (master if none) of @ses that can be used to send
995 * If we are currently binding a new channel (negprot/sess.setup),
996 * return the new incomplete channel.
998 struct TCP_Server_Info
*cifs_pick_channel(struct cifs_ses
*ses
)
1005 if (!ses
->binding
) {
1007 if (ses
->chan_count
> 1) {
1008 index
= (uint
)atomic_inc_return(&ses
->chan_seq
);
1009 index
%= ses
->chan_count
;
1011 return ses
->chans
[index
].server
;
1013 return cifs_ses_server(ses
);
1018 compound_send_recv(const unsigned int xid
, struct cifs_ses
*ses
,
1019 struct TCP_Server_Info
*server
,
1020 const int flags
, const int num_rqst
, struct smb_rqst
*rqst
,
1021 int *resp_buf_type
, struct kvec
*resp_iov
)
1023 int i
, j
, optype
, rc
= 0;
1024 struct mid_q_entry
*midQ
[MAX_COMPOUND
];
1025 bool cancelled_mid
[MAX_COMPOUND
] = {false};
1026 struct cifs_credits credits
[MAX_COMPOUND
] = {
1027 { .value
= 0, .instance
= 0 }
1029 unsigned int instance
;
1032 optype
= flags
& CIFS_OP_MASK
;
1034 for (i
= 0; i
< num_rqst
; i
++)
1035 resp_buf_type
[i
] = CIFS_NO_BUFFER
; /* no response buf yet */
1037 if (!ses
|| !ses
->server
|| !server
) {
1038 cifs_dbg(VFS
, "Null session\n");
1042 if (server
->tcpStatus
== CifsExiting
)
1046 * Wait for all the requests to become available.
1047 * This approach still leaves the possibility to be stuck waiting for
1048 * credits if the server doesn't grant credits to the outstanding
1049 * requests and if the client is completely idle, not generating any
1051 * This can be handled by the eventual session reconnect.
1053 rc
= wait_for_compound_request(server
, num_rqst
, flags
,
1058 for (i
= 0; i
< num_rqst
; i
++) {
1059 credits
[i
].value
= 1;
1060 credits
[i
].instance
= instance
;
1064 * Make sure that we sign in the same order that we send on this socket
1065 * and avoid races inside tcp sendmsg code that could cause corruption
1069 mutex_lock(&server
->srv_mutex
);
1072 * All the parts of the compound chain belong obtained credits from the
1073 * same session. We can not use credits obtained from the previous
1074 * session to send this request. Check if there were reconnects after
1075 * we obtained credits and return -EAGAIN in such cases to let callers
1078 if (instance
!= server
->reconnect_instance
) {
1079 mutex_unlock(&server
->srv_mutex
);
1080 for (j
= 0; j
< num_rqst
; j
++)
1081 add_credits(server
, &credits
[j
], optype
);
1085 for (i
= 0; i
< num_rqst
; i
++) {
1086 midQ
[i
] = server
->ops
->setup_request(ses
, server
, &rqst
[i
]);
1087 if (IS_ERR(midQ
[i
])) {
1088 revert_current_mid(server
, i
);
1089 for (j
= 0; j
< i
; j
++)
1090 cifs_delete_mid(midQ
[j
]);
1091 mutex_unlock(&server
->srv_mutex
);
1093 /* Update # of requests on wire to server */
1094 for (j
= 0; j
< num_rqst
; j
++)
1095 add_credits(server
, &credits
[j
], optype
);
1096 return PTR_ERR(midQ
[i
]);
1099 midQ
[i
]->mid_state
= MID_REQUEST_SUBMITTED
;
1100 midQ
[i
]->optype
= optype
;
1102 * Invoke callback for every part of the compound chain
1103 * to calculate credits properly. Wake up this thread only when
1104 * the last element is received.
1106 if (i
< num_rqst
- 1)
1107 midQ
[i
]->callback
= cifs_compound_callback
;
1109 midQ
[i
]->callback
= cifs_compound_last_callback
;
1111 cifs_in_send_inc(server
);
1112 rc
= smb_send_rqst(server
, num_rqst
, rqst
, flags
);
1113 cifs_in_send_dec(server
);
1115 for (i
= 0; i
< num_rqst
; i
++)
1116 cifs_save_when_sent(midQ
[i
]);
1119 revert_current_mid(server
, num_rqst
);
1120 server
->sequence_number
-= 2;
1123 mutex_unlock(&server
->srv_mutex
);
1126 * If sending failed for some reason or it is an oplock break that we
1127 * will not receive a response to - return credits back
1129 if (rc
< 0 || (flags
& CIFS_NO_SRV_RSP
)) {
1130 for (i
= 0; i
< num_rqst
; i
++)
1131 add_credits(server
, &credits
[i
], optype
);
1136 * At this point the request is passed to the network stack - we assume
1137 * that any credits taken from the server structure on the client have
1138 * been spent and we can't return them back. Once we receive responses
1139 * we will collect credits granted by the server in the mid callbacks
1140 * and add those credits to the server structure.
1144 * Compounding is never used during session establish.
1146 if ((ses
->status
== CifsNew
) || (optype
& CIFS_NEG_OP
))
1147 smb311_update_preauth_hash(ses
, rqst
[0].rq_iov
,
1150 for (i
= 0; i
< num_rqst
; i
++) {
1151 rc
= wait_for_response(server
, midQ
[i
]);
1156 for (; i
< num_rqst
; i
++) {
1157 cifs_server_dbg(VFS
, "Cancelling wait for mid %llu cmd: %d\n",
1158 midQ
[i
]->mid
, le16_to_cpu(midQ
[i
]->command
));
1159 send_cancel(server
, &rqst
[i
], midQ
[i
]);
1160 spin_lock(&GlobalMid_Lock
);
1161 midQ
[i
]->mid_flags
|= MID_WAIT_CANCELLED
;
1162 if (midQ
[i
]->mid_state
== MID_REQUEST_SUBMITTED
) {
1163 midQ
[i
]->callback
= cifs_cancelled_callback
;
1164 cancelled_mid
[i
] = true;
1165 credits
[i
].value
= 0;
1167 spin_unlock(&GlobalMid_Lock
);
1171 for (i
= 0; i
< num_rqst
; i
++) {
1175 rc
= cifs_sync_mid_result(midQ
[i
], server
);
1177 /* mark this mid as cancelled to not free it below */
1178 cancelled_mid
[i
] = true;
1182 if (!midQ
[i
]->resp_buf
||
1183 midQ
[i
]->mid_state
!= MID_RESPONSE_RECEIVED
) {
1185 cifs_dbg(FYI
, "Bad MID state?\n");
1189 buf
= (char *)midQ
[i
]->resp_buf
;
1190 resp_iov
[i
].iov_base
= buf
;
1191 resp_iov
[i
].iov_len
= midQ
[i
]->resp_buf_size
+
1192 server
->vals
->header_preamble_size
;
1194 if (midQ
[i
]->large_buf
)
1195 resp_buf_type
[i
] = CIFS_LARGE_BUFFER
;
1197 resp_buf_type
[i
] = CIFS_SMALL_BUFFER
;
1199 rc
= server
->ops
->check_receive(midQ
[i
], server
,
1200 flags
& CIFS_LOG_ERROR
);
1202 /* mark it so buf will not be freed by cifs_delete_mid */
1203 if ((flags
& CIFS_NO_RSP_BUF
) == 0)
1204 midQ
[i
]->resp_buf
= NULL
;
1209 * Compounding is never used during session establish.
1211 if ((ses
->status
== CifsNew
) || (optype
& CIFS_NEG_OP
)) {
1213 .iov_base
= resp_iov
[0].iov_base
,
1214 .iov_len
= resp_iov
[0].iov_len
1216 smb311_update_preauth_hash(ses
, &iov
, 1);
1221 * This will dequeue all mids. After this it is important that the
1222 * demultiplex_thread will not process any of these mids any futher.
1223 * This is prevented above by using a noop callback that will not
1224 * wake this thread except for the very last PDU.
1226 for (i
= 0; i
< num_rqst
; i
++) {
1227 if (!cancelled_mid
[i
])
1228 cifs_delete_mid(midQ
[i
]);
1235 cifs_send_recv(const unsigned int xid
, struct cifs_ses
*ses
,
1236 struct TCP_Server_Info
*server
,
1237 struct smb_rqst
*rqst
, int *resp_buf_type
, const int flags
,
1238 struct kvec
*resp_iov
)
1240 return compound_send_recv(xid
, ses
, server
, flags
, 1,
1241 rqst
, resp_buf_type
, resp_iov
);
1245 SendReceive2(const unsigned int xid
, struct cifs_ses
*ses
,
1246 struct kvec
*iov
, int n_vec
, int *resp_buf_type
/* ret */,
1247 const int flags
, struct kvec
*resp_iov
)
1249 struct smb_rqst rqst
;
1250 struct kvec s_iov
[CIFS_MAX_IOV_SIZE
], *new_iov
;
1253 if (n_vec
+ 1 > CIFS_MAX_IOV_SIZE
) {
1254 new_iov
= kmalloc_array(n_vec
+ 1, sizeof(struct kvec
),
1257 /* otherwise cifs_send_recv below sets resp_buf_type */
1258 *resp_buf_type
= CIFS_NO_BUFFER
;
1264 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1265 memcpy(new_iov
+ 1, iov
, (sizeof(struct kvec
) * n_vec
));
1267 new_iov
[0].iov_base
= new_iov
[1].iov_base
;
1268 new_iov
[0].iov_len
= 4;
1269 new_iov
[1].iov_base
+= 4;
1270 new_iov
[1].iov_len
-= 4;
1272 memset(&rqst
, 0, sizeof(struct smb_rqst
));
1273 rqst
.rq_iov
= new_iov
;
1274 rqst
.rq_nvec
= n_vec
+ 1;
1276 rc
= cifs_send_recv(xid
, ses
, ses
->server
,
1277 &rqst
, resp_buf_type
, flags
, resp_iov
);
1278 if (n_vec
+ 1 > CIFS_MAX_IOV_SIZE
)
1284 SendReceive(const unsigned int xid
, struct cifs_ses
*ses
,
1285 struct smb_hdr
*in_buf
, struct smb_hdr
*out_buf
,
1286 int *pbytes_returned
, const int flags
)
1289 struct mid_q_entry
*midQ
;
1290 unsigned int len
= be32_to_cpu(in_buf
->smb_buf_length
);
1291 struct kvec iov
= { .iov_base
= in_buf
, .iov_len
= len
};
1292 struct smb_rqst rqst
= { .rq_iov
= &iov
, .rq_nvec
= 1 };
1293 struct cifs_credits credits
= { .value
= 1, .instance
= 0 };
1294 struct TCP_Server_Info
*server
;
1297 cifs_dbg(VFS
, "Null smb session\n");
1300 server
= ses
->server
;
1301 if (server
== NULL
) {
1302 cifs_dbg(VFS
, "Null tcp session\n");
1306 if (server
->tcpStatus
== CifsExiting
)
1309 /* Ensure that we do not send more than 50 overlapping requests
1310 to the same server. We may make this configurable later or
1313 if (len
> CIFSMaxBufSize
+ MAX_CIFS_HDR_SIZE
- 4) {
1314 cifs_server_dbg(VFS
, "Invalid length, greater than maximum frame, %d\n",
1319 rc
= wait_for_free_request(server
, flags
, &credits
.instance
);
1323 /* make sure that we sign in the same order that we send on this socket
1324 and avoid races inside tcp sendmsg code that could cause corruption
1327 mutex_lock(&server
->srv_mutex
);
1329 rc
= allocate_mid(ses
, in_buf
, &midQ
);
1331 mutex_unlock(&server
->srv_mutex
);
1332 /* Update # of requests on wire to server */
1333 add_credits(server
, &credits
, 0);
1337 rc
= cifs_sign_smb(in_buf
, server
, &midQ
->sequence_number
);
1339 mutex_unlock(&server
->srv_mutex
);
1343 midQ
->mid_state
= MID_REQUEST_SUBMITTED
;
1345 cifs_in_send_inc(server
);
1346 rc
= smb_send(server
, in_buf
, len
);
1347 cifs_in_send_dec(server
);
1348 cifs_save_when_sent(midQ
);
1351 server
->sequence_number
-= 2;
1353 mutex_unlock(&server
->srv_mutex
);
1358 rc
= wait_for_response(server
, midQ
);
1360 send_cancel(server
, &rqst
, midQ
);
1361 spin_lock(&GlobalMid_Lock
);
1362 if (midQ
->mid_state
== MID_REQUEST_SUBMITTED
) {
1363 /* no longer considered to be "in-flight" */
1364 midQ
->callback
= DeleteMidQEntry
;
1365 spin_unlock(&GlobalMid_Lock
);
1366 add_credits(server
, &credits
, 0);
1369 spin_unlock(&GlobalMid_Lock
);
1372 rc
= cifs_sync_mid_result(midQ
, server
);
1374 add_credits(server
, &credits
, 0);
1378 if (!midQ
->resp_buf
|| !out_buf
||
1379 midQ
->mid_state
!= MID_RESPONSE_RECEIVED
) {
1381 cifs_server_dbg(VFS
, "Bad MID state?\n");
1385 *pbytes_returned
= get_rfc1002_length(midQ
->resp_buf
);
1386 memcpy(out_buf
, midQ
->resp_buf
, *pbytes_returned
+ 4);
1387 rc
= cifs_check_receive(midQ
, server
, 0);
1389 cifs_delete_mid(midQ
);
1390 add_credits(server
, &credits
, 0);
1395 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1396 blocking lock to return. */
1399 send_lock_cancel(const unsigned int xid
, struct cifs_tcon
*tcon
,
1400 struct smb_hdr
*in_buf
,
1401 struct smb_hdr
*out_buf
)
1404 struct cifs_ses
*ses
= tcon
->ses
;
1405 LOCK_REQ
*pSMB
= (LOCK_REQ
*)in_buf
;
1407 /* We just modify the current in_buf to change
1408 the type of lock from LOCKING_ANDX_SHARED_LOCK
1409 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1410 LOCKING_ANDX_CANCEL_LOCK. */
1412 pSMB
->LockType
= LOCKING_ANDX_CANCEL_LOCK
|LOCKING_ANDX_LARGE_FILES
;
1414 pSMB
->hdr
.Mid
= get_next_mid(ses
->server
);
1416 return SendReceive(xid
, ses
, in_buf
, out_buf
,
1417 &bytes_returned
, 0);
1421 SendReceiveBlockingLock(const unsigned int xid
, struct cifs_tcon
*tcon
,
1422 struct smb_hdr
*in_buf
, struct smb_hdr
*out_buf
,
1423 int *pbytes_returned
)
1427 struct mid_q_entry
*midQ
;
1428 struct cifs_ses
*ses
;
1429 unsigned int len
= be32_to_cpu(in_buf
->smb_buf_length
);
1430 struct kvec iov
= { .iov_base
= in_buf
, .iov_len
= len
};
1431 struct smb_rqst rqst
= { .rq_iov
= &iov
, .rq_nvec
= 1 };
1432 unsigned int instance
;
1433 struct TCP_Server_Info
*server
;
1435 if (tcon
== NULL
|| tcon
->ses
== NULL
) {
1436 cifs_dbg(VFS
, "Null smb session\n");
1440 server
= ses
->server
;
1442 if (server
== NULL
) {
1443 cifs_dbg(VFS
, "Null tcp session\n");
1447 if (server
->tcpStatus
== CifsExiting
)
1450 /* Ensure that we do not send more than 50 overlapping requests
1451 to the same server. We may make this configurable later or
1454 if (len
> CIFSMaxBufSize
+ MAX_CIFS_HDR_SIZE
- 4) {
1455 cifs_tcon_dbg(VFS
, "Invalid length, greater than maximum frame, %d\n",
1460 rc
= wait_for_free_request(server
, CIFS_BLOCKING_OP
, &instance
);
1464 /* make sure that we sign in the same order that we send on this socket
1465 and avoid races inside tcp sendmsg code that could cause corruption
1468 mutex_lock(&server
->srv_mutex
);
1470 rc
= allocate_mid(ses
, in_buf
, &midQ
);
1472 mutex_unlock(&server
->srv_mutex
);
1476 rc
= cifs_sign_smb(in_buf
, server
, &midQ
->sequence_number
);
1478 cifs_delete_mid(midQ
);
1479 mutex_unlock(&server
->srv_mutex
);
1483 midQ
->mid_state
= MID_REQUEST_SUBMITTED
;
1484 cifs_in_send_inc(server
);
1485 rc
= smb_send(server
, in_buf
, len
);
1486 cifs_in_send_dec(server
);
1487 cifs_save_when_sent(midQ
);
1490 server
->sequence_number
-= 2;
1492 mutex_unlock(&server
->srv_mutex
);
1495 cifs_delete_mid(midQ
);
1499 /* Wait for a reply - allow signals to interrupt. */
1500 rc
= wait_event_interruptible(server
->response_q
,
1501 (!(midQ
->mid_state
== MID_REQUEST_SUBMITTED
)) ||
1502 ((server
->tcpStatus
!= CifsGood
) &&
1503 (server
->tcpStatus
!= CifsNew
)));
1505 /* Were we interrupted by a signal ? */
1506 if ((rc
== -ERESTARTSYS
) &&
1507 (midQ
->mid_state
== MID_REQUEST_SUBMITTED
) &&
1508 ((server
->tcpStatus
== CifsGood
) ||
1509 (server
->tcpStatus
== CifsNew
))) {
1511 if (in_buf
->Command
== SMB_COM_TRANSACTION2
) {
1512 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1513 blocking lock to return. */
1514 rc
= send_cancel(server
, &rqst
, midQ
);
1516 cifs_delete_mid(midQ
);
1520 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1521 to cause the blocking lock to return. */
1523 rc
= send_lock_cancel(xid
, tcon
, in_buf
, out_buf
);
1525 /* If we get -ENOLCK back the lock may have
1526 already been removed. Don't exit in this case. */
1527 if (rc
&& rc
!= -ENOLCK
) {
1528 cifs_delete_mid(midQ
);
1533 rc
= wait_for_response(server
, midQ
);
1535 send_cancel(server
, &rqst
, midQ
);
1536 spin_lock(&GlobalMid_Lock
);
1537 if (midQ
->mid_state
== MID_REQUEST_SUBMITTED
) {
1538 /* no longer considered to be "in-flight" */
1539 midQ
->callback
= DeleteMidQEntry
;
1540 spin_unlock(&GlobalMid_Lock
);
1543 spin_unlock(&GlobalMid_Lock
);
1546 /* We got the response - restart system call. */
1550 rc
= cifs_sync_mid_result(midQ
, server
);
1554 /* rcvd frame is ok */
1555 if (out_buf
== NULL
|| midQ
->mid_state
!= MID_RESPONSE_RECEIVED
) {
1557 cifs_tcon_dbg(VFS
, "Bad MID state?\n");
1561 *pbytes_returned
= get_rfc1002_length(midQ
->resp_buf
);
1562 memcpy(out_buf
, midQ
->resp_buf
, *pbytes_returned
+ 4);
1563 rc
= cifs_check_receive(midQ
, server
, 0);
1565 cifs_delete_mid(midQ
);
1566 if (rstart
&& rc
== -EACCES
)
1567 return -ERESTARTSYS
;