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(" CIFS 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
;
329 __be32 rfc1002_marker
;
331 if (cifs_rdma_enabled(server
)) {
332 /* return -EAGAIN when connecting or reconnecting */
334 if (server
->smbd_conn
)
335 rc
= smbd_send(server
, num_rqst
, rqst
);
342 if (signal_pending(current
)) {
343 cifs_dbg(FYI
, "signal is pending before sending any data\n");
347 /* cork the socket */
348 kernel_setsockopt(ssocket
, SOL_TCP
, TCP_CORK
,
349 (char *)&val
, sizeof(val
));
351 for (j
= 0; j
< num_rqst
; j
++)
352 send_length
+= smb_rqst_len(server
, &rqst
[j
]);
353 rfc1002_marker
= cpu_to_be32(send_length
);
356 * We should not allow signals to interrupt the network send because
357 * any partial send will cause session reconnects thus increasing
358 * latency of system calls and overload a server with unnecessary
363 sigprocmask(SIG_BLOCK
, &mask
, &oldmask
);
365 /* Generate a rfc1002 marker for SMB2+ */
366 if (server
->vals
->header_preamble_size
== 0) {
368 .iov_base
= &rfc1002_marker
,
371 iov_iter_kvec(&smb_msg
.msg_iter
, WRITE
, &hiov
, 1, 4);
372 rc
= smb_send_kvec(server
, &smb_msg
, &sent
);
380 cifs_dbg(FYI
, "Sending smb: smb_len=%u\n", send_length
);
382 for (j
= 0; j
< num_rqst
; j
++) {
383 iov
= rqst
[j
].rq_iov
;
384 n_vec
= rqst
[j
].rq_nvec
;
387 for (i
= 0; i
< n_vec
; i
++) {
388 dump_smb(iov
[i
].iov_base
, iov
[i
].iov_len
);
389 size
+= iov
[i
].iov_len
;
392 iov_iter_kvec(&smb_msg
.msg_iter
, WRITE
, iov
, n_vec
, size
);
394 rc
= smb_send_kvec(server
, &smb_msg
, &sent
);
400 /* now walk the page array and send each page in it */
401 for (i
= 0; i
< rqst
[j
].rq_npages
; i
++) {
404 bvec
.bv_page
= rqst
[j
].rq_pages
[i
];
405 rqst_page_get_length(&rqst
[j
], i
, &bvec
.bv_len
,
408 iov_iter_bvec(&smb_msg
.msg_iter
, WRITE
,
409 &bvec
, 1, bvec
.bv_len
);
410 rc
= smb_send_kvec(server
, &smb_msg
, &sent
);
419 sigprocmask(SIG_SETMASK
, &oldmask
, NULL
);
422 * If signal is pending but we have already sent the whole packet to
423 * the server we need to return success status to allow a corresponding
424 * mid entry to be kept in the pending requests queue thus allowing
425 * to handle responses from the server by the client.
427 * If only part of the packet has been sent there is no need to hide
428 * interrupt because the session will be reconnected anyway, so there
429 * won't be any response from the server to handle.
432 if (signal_pending(current
) && (total_len
!= send_length
)) {
433 cifs_dbg(FYI
, "signal is pending after attempt to send\n");
439 kernel_setsockopt(ssocket
, SOL_TCP
, TCP_CORK
,
440 (char *)&val
, sizeof(val
));
442 if ((total_len
> 0) && (total_len
!= send_length
)) {
443 cifs_dbg(FYI
, "partial send (wanted=%u sent=%zu): terminating session\n",
444 send_length
, total_len
);
446 * If we have only sent part of an SMB then the next SMB could
447 * be taken as the remainder of this one. We need to kill the
448 * socket so the server throws away the partial SMB
450 server
->tcpStatus
= CifsNeedReconnect
;
451 trace_smb3_partial_send_reconnect(server
->CurrentMid
,
455 if (rc
< 0 && rc
!= -EINTR
)
456 cifs_server_dbg(VFS
, "Error %d sending data on socket to server\n",
465 smb_send_rqst(struct TCP_Server_Info
*server
, int num_rqst
,
466 struct smb_rqst
*rqst
, int flags
)
469 struct smb2_transform_hdr tr_hdr
;
470 struct smb_rqst cur_rqst
[MAX_COMPOUND
];
473 if (!(flags
& CIFS_TRANSFORM_REQ
))
474 return __smb_send_rqst(server
, num_rqst
, rqst
);
476 if (num_rqst
> MAX_COMPOUND
- 1)
479 memset(&cur_rqst
[0], 0, sizeof(cur_rqst
));
480 memset(&iov
, 0, sizeof(iov
));
481 memset(&tr_hdr
, 0, sizeof(tr_hdr
));
483 iov
.iov_base
= &tr_hdr
;
484 iov
.iov_len
= sizeof(tr_hdr
);
485 cur_rqst
[0].rq_iov
= &iov
;
486 cur_rqst
[0].rq_nvec
= 1;
488 if (!server
->ops
->init_transform_rq
) {
489 cifs_server_dbg(VFS
, "Encryption requested but transform "
490 "callback is missing\n");
494 rc
= server
->ops
->init_transform_rq(server
, num_rqst
+ 1,
499 rc
= __smb_send_rqst(server
, num_rqst
+ 1, &cur_rqst
[0]);
500 smb3_free_compound_rqst(num_rqst
, &cur_rqst
[1]);
505 smb_send(struct TCP_Server_Info
*server
, struct smb_hdr
*smb_buffer
,
506 unsigned int smb_buf_length
)
509 struct smb_rqst rqst
= { .rq_iov
= iov
,
512 iov
[0].iov_base
= smb_buffer
;
514 iov
[1].iov_base
= (char *)smb_buffer
+ 4;
515 iov
[1].iov_len
= smb_buf_length
;
517 return __smb_send_rqst(server
, 1, &rqst
);
521 wait_for_free_credits(struct TCP_Server_Info
*server
, const int num_credits
,
522 const int timeout
, const int flags
,
523 unsigned int *instance
)
531 t
= MAX_JIFFY_OFFSET
;
533 t
= msecs_to_jiffies(timeout
);
535 optype
= flags
& CIFS_OP_MASK
;
539 credits
= server
->ops
->get_credits_field(server
, optype
);
540 /* Since an echo is already inflight, no need to wait to send another */
541 if (*credits
<= 0 && optype
== CIFS_ECHO_OP
)
544 spin_lock(&server
->req_lock
);
545 if ((flags
& CIFS_TIMEOUT_MASK
) == CIFS_NON_BLOCKING
) {
546 /* oplock breaks must not be held up */
548 if (server
->in_flight
> server
->max_in_flight
)
549 server
->max_in_flight
= server
->in_flight
;
551 *instance
= server
->reconnect_instance
;
552 spin_unlock(&server
->req_lock
);
557 if (*credits
< num_credits
) {
558 spin_unlock(&server
->req_lock
);
559 cifs_num_waiters_inc(server
);
560 rc
= wait_event_killable_timeout(server
->request_q
,
561 has_credits(server
, credits
, num_credits
), t
);
562 cifs_num_waiters_dec(server
);
564 trace_smb3_credit_timeout(server
->CurrentMid
,
565 server
->hostname
, num_credits
);
566 cifs_server_dbg(VFS
, "wait timed out after %d ms\n",
570 if (rc
== -ERESTARTSYS
)
572 spin_lock(&server
->req_lock
);
574 if (server
->tcpStatus
== CifsExiting
) {
575 spin_unlock(&server
->req_lock
);
580 * For normal commands, reserve the last MAX_COMPOUND
581 * credits to compound requests.
582 * Otherwise these compounds could be permanently
583 * starved for credits by single-credit requests.
585 * To prevent spinning CPU, block this thread until
586 * there are >MAX_COMPOUND credits available.
587 * But only do this is we already have a lot of
588 * credits in flight to avoid triggering this check
589 * for servers that are slow to hand out credits on
592 if (!optype
&& num_credits
== 1 &&
593 server
->in_flight
> 2 * MAX_COMPOUND
&&
594 *credits
<= MAX_COMPOUND
) {
595 spin_unlock(&server
->req_lock
);
596 cifs_num_waiters_inc(server
);
597 rc
= wait_event_killable_timeout(
599 has_credits(server
, credits
,
602 cifs_num_waiters_dec(server
);
604 trace_smb3_credit_timeout(
606 server
->hostname
, num_credits
);
607 cifs_server_dbg(VFS
, "wait timed out after %d ms\n",
611 if (rc
== -ERESTARTSYS
)
613 spin_lock(&server
->req_lock
);
618 * Can not count locking commands against total
619 * as they are allowed to block on server.
622 /* update # of requests on the wire to server */
623 if ((flags
& CIFS_TIMEOUT_MASK
) != CIFS_BLOCKING_OP
) {
624 *credits
-= num_credits
;
625 server
->in_flight
+= num_credits
;
626 if (server
->in_flight
> server
->max_in_flight
)
627 server
->max_in_flight
= server
->in_flight
;
628 *instance
= server
->reconnect_instance
;
630 spin_unlock(&server
->req_lock
);
638 wait_for_free_request(struct TCP_Server_Info
*server
, const int flags
,
639 unsigned int *instance
)
641 return wait_for_free_credits(server
, 1, -1, flags
,
646 wait_for_compound_request(struct TCP_Server_Info
*server
, int num
,
647 const int flags
, unsigned int *instance
)
651 credits
= server
->ops
->get_credits_field(server
, flags
& CIFS_OP_MASK
);
653 spin_lock(&server
->req_lock
);
654 if (*credits
< num
) {
656 * Return immediately if not too many requests in flight since
657 * we will likely be stuck on waiting for credits.
659 if (server
->in_flight
< num
- *credits
) {
660 spin_unlock(&server
->req_lock
);
664 spin_unlock(&server
->req_lock
);
666 return wait_for_free_credits(server
, num
, 60000, flags
,
671 cifs_wait_mtu_credits(struct TCP_Server_Info
*server
, unsigned int size
,
672 unsigned int *num
, struct cifs_credits
*credits
)
676 credits
->instance
= server
->reconnect_instance
;
680 static int allocate_mid(struct cifs_ses
*ses
, struct smb_hdr
*in_buf
,
681 struct mid_q_entry
**ppmidQ
)
683 if (ses
->server
->tcpStatus
== CifsExiting
) {
687 if (ses
->server
->tcpStatus
== CifsNeedReconnect
) {
688 cifs_dbg(FYI
, "tcp session dead - return to caller to retry\n");
692 if (ses
->status
== CifsNew
) {
693 if ((in_buf
->Command
!= SMB_COM_SESSION_SETUP_ANDX
) &&
694 (in_buf
->Command
!= SMB_COM_NEGOTIATE
))
696 /* else ok - we are setting up session */
699 if (ses
->status
== CifsExiting
) {
700 /* check if SMB session is bad because we are setting it up */
701 if (in_buf
->Command
!= SMB_COM_LOGOFF_ANDX
)
703 /* else ok - we are shutting down session */
706 *ppmidQ
= AllocMidQEntry(in_buf
, ses
->server
);
709 spin_lock(&GlobalMid_Lock
);
710 list_add_tail(&(*ppmidQ
)->qhead
, &ses
->server
->pending_mid_q
);
711 spin_unlock(&GlobalMid_Lock
);
716 wait_for_response(struct TCP_Server_Info
*server
, struct mid_q_entry
*midQ
)
720 error
= wait_event_freezekillable_unsafe(server
->response_q
,
721 midQ
->mid_state
!= MID_REQUEST_SUBMITTED
);
729 cifs_setup_async_request(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
)
732 struct smb_hdr
*hdr
= (struct smb_hdr
*)rqst
->rq_iov
[0].iov_base
;
733 struct mid_q_entry
*mid
;
735 if (rqst
->rq_iov
[0].iov_len
!= 4 ||
736 rqst
->rq_iov
[0].iov_base
+ 4 != rqst
->rq_iov
[1].iov_base
)
737 return ERR_PTR(-EIO
);
739 /* enable signing if server requires it */
741 hdr
->Flags2
|= SMBFLG2_SECURITY_SIGNATURE
;
743 mid
= AllocMidQEntry(hdr
, server
);
745 return ERR_PTR(-ENOMEM
);
747 rc
= cifs_sign_rqst(rqst
, server
, &mid
->sequence_number
);
749 DeleteMidQEntry(mid
);
757 * Send a SMB request and set the callback function in the mid to handle
758 * the result. Caller is responsible for dealing with timeouts.
761 cifs_call_async(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
,
762 mid_receive_t
*receive
, mid_callback_t
*callback
,
763 mid_handle_t
*handle
, void *cbdata
, const int flags
,
764 const struct cifs_credits
*exist_credits
)
767 struct mid_q_entry
*mid
;
768 struct cifs_credits credits
= { .value
= 0, .instance
= 0 };
769 unsigned int instance
;
772 optype
= flags
& CIFS_OP_MASK
;
774 if ((flags
& CIFS_HAS_CREDITS
) == 0) {
775 rc
= wait_for_free_request(server
, flags
, &instance
);
779 credits
.instance
= instance
;
781 instance
= exist_credits
->instance
;
783 mutex_lock(&server
->srv_mutex
);
786 * We can't use credits obtained from the previous session to send this
787 * request. Check if there were reconnects after we obtained credits and
788 * return -EAGAIN in such cases to let callers handle it.
790 if (instance
!= server
->reconnect_instance
) {
791 mutex_unlock(&server
->srv_mutex
);
792 add_credits_and_wake_if(server
, &credits
, optype
);
796 mid
= server
->ops
->setup_async_request(server
, rqst
);
798 mutex_unlock(&server
->srv_mutex
);
799 add_credits_and_wake_if(server
, &credits
, optype
);
803 mid
->receive
= receive
;
804 mid
->callback
= callback
;
805 mid
->callback_data
= cbdata
;
806 mid
->handle
= handle
;
807 mid
->mid_state
= MID_REQUEST_SUBMITTED
;
809 /* put it on the pending_mid_q */
810 spin_lock(&GlobalMid_Lock
);
811 list_add_tail(&mid
->qhead
, &server
->pending_mid_q
);
812 spin_unlock(&GlobalMid_Lock
);
815 * Need to store the time in mid before calling I/O. For call_async,
816 * I/O response may come back and free the mid entry on another thread.
818 cifs_save_when_sent(mid
);
819 cifs_in_send_inc(server
);
820 rc
= smb_send_rqst(server
, 1, rqst
, flags
);
821 cifs_in_send_dec(server
);
824 revert_current_mid(server
, mid
->credits
);
825 server
->sequence_number
-= 2;
826 cifs_delete_mid(mid
);
829 mutex_unlock(&server
->srv_mutex
);
834 add_credits_and_wake_if(server
, &credits
, optype
);
840 * Send an SMB Request. No response info (other than return code)
841 * needs to be parsed.
843 * flags indicate the type of request buffer and how long to wait
844 * and whether to log NT STATUS code (error) before mapping it to POSIX error
848 SendReceiveNoRsp(const unsigned int xid
, struct cifs_ses
*ses
,
849 char *in_buf
, int flags
)
856 iov
[0].iov_base
= in_buf
;
857 iov
[0].iov_len
= get_rfc1002_length(in_buf
) + 4;
858 flags
|= CIFS_NO_RSP_BUF
;
859 rc
= SendReceive2(xid
, ses
, iov
, 1, &resp_buf_type
, flags
, &rsp_iov
);
860 cifs_dbg(NOISY
, "SendRcvNoRsp flags %d rc %d\n", flags
, rc
);
866 cifs_sync_mid_result(struct mid_q_entry
*mid
, struct TCP_Server_Info
*server
)
870 cifs_dbg(FYI
, "%s: cmd=%d mid=%llu state=%d\n",
871 __func__
, le16_to_cpu(mid
->command
), mid
->mid
, mid
->mid_state
);
873 spin_lock(&GlobalMid_Lock
);
874 switch (mid
->mid_state
) {
875 case MID_RESPONSE_RECEIVED
:
876 spin_unlock(&GlobalMid_Lock
);
878 case MID_RETRY_NEEDED
:
881 case MID_RESPONSE_MALFORMED
:
888 if (!(mid
->mid_flags
& MID_DELETED
)) {
889 list_del_init(&mid
->qhead
);
890 mid
->mid_flags
|= MID_DELETED
;
892 cifs_server_dbg(VFS
, "%s: invalid mid state mid=%llu state=%d\n",
893 __func__
, mid
->mid
, mid
->mid_state
);
896 spin_unlock(&GlobalMid_Lock
);
898 DeleteMidQEntry(mid
);
903 send_cancel(struct TCP_Server_Info
*server
, struct smb_rqst
*rqst
,
904 struct mid_q_entry
*mid
)
906 return server
->ops
->send_cancel
?
907 server
->ops
->send_cancel(server
, rqst
, mid
) : 0;
911 cifs_check_receive(struct mid_q_entry
*mid
, struct TCP_Server_Info
*server
,
914 unsigned int len
= get_rfc1002_length(mid
->resp_buf
) + 4;
916 dump_smb(mid
->resp_buf
, min_t(u32
, 92, len
));
918 /* convert the length into a more usable form */
922 struct smb_rqst rqst
= { .rq_iov
= iov
,
925 iov
[0].iov_base
= mid
->resp_buf
;
927 iov
[1].iov_base
= (char *)mid
->resp_buf
+ 4;
928 iov
[1].iov_len
= len
- 4;
929 /* FIXME: add code to kill session */
930 rc
= cifs_verify_signature(&rqst
, server
,
931 mid
->sequence_number
);
933 cifs_server_dbg(VFS
, "SMB signature verification returned error = %d\n",
937 /* BB special case reconnect tid and uid here? */
938 return map_smb_to_linux_error(mid
->resp_buf
, log_error
);
942 cifs_setup_request(struct cifs_ses
*ses
, struct TCP_Server_Info
*ignored
,
943 struct smb_rqst
*rqst
)
946 struct smb_hdr
*hdr
= (struct smb_hdr
*)rqst
->rq_iov
[0].iov_base
;
947 struct mid_q_entry
*mid
;
949 if (rqst
->rq_iov
[0].iov_len
!= 4 ||
950 rqst
->rq_iov
[0].iov_base
+ 4 != rqst
->rq_iov
[1].iov_base
)
951 return ERR_PTR(-EIO
);
953 rc
= allocate_mid(ses
, hdr
, &mid
);
956 rc
= cifs_sign_rqst(rqst
, ses
->server
, &mid
->sequence_number
);
958 cifs_delete_mid(mid
);
965 cifs_compound_callback(struct mid_q_entry
*mid
)
967 struct TCP_Server_Info
*server
= mid
->server
;
968 struct cifs_credits credits
;
970 credits
.value
= server
->ops
->get_credits(mid
);
971 credits
.instance
= server
->reconnect_instance
;
973 add_credits(server
, &credits
, mid
->optype
);
977 cifs_compound_last_callback(struct mid_q_entry
*mid
)
979 cifs_compound_callback(mid
);
980 cifs_wake_up_task(mid
);
984 cifs_cancelled_callback(struct mid_q_entry
*mid
)
986 cifs_compound_callback(mid
);
987 DeleteMidQEntry(mid
);
991 compound_send_recv(const unsigned int xid
, struct cifs_ses
*ses
,
992 const int flags
, const int num_rqst
, struct smb_rqst
*rqst
,
993 int *resp_buf_type
, struct kvec
*resp_iov
)
995 int i
, j
, optype
, rc
= 0;
996 struct mid_q_entry
*midQ
[MAX_COMPOUND
];
997 bool cancelled_mid
[MAX_COMPOUND
] = {false};
998 struct cifs_credits credits
[MAX_COMPOUND
] = {
999 { .value
= 0, .instance
= 0 }
1001 unsigned int instance
;
1003 struct TCP_Server_Info
*server
;
1005 optype
= flags
& CIFS_OP_MASK
;
1007 for (i
= 0; i
< num_rqst
; i
++)
1008 resp_buf_type
[i
] = CIFS_NO_BUFFER
; /* no response buf yet */
1010 if ((ses
== NULL
) || (ses
->server
== NULL
)) {
1011 cifs_dbg(VFS
, "Null session\n");
1015 if (!ses
->binding
) {
1018 if (ses
->chan_count
> 1) {
1019 index
= (uint
)atomic_inc_return(&ses
->chan_seq
);
1020 index
%= ses
->chan_count
;
1022 server
= ses
->chans
[index
].server
;
1024 server
= cifs_ses_server(ses
);
1027 if (server
->tcpStatus
== CifsExiting
)
1031 * Wait for all the requests to become available.
1032 * This approach still leaves the possibility to be stuck waiting for
1033 * credits if the server doesn't grant credits to the outstanding
1034 * requests and if the client is completely idle, not generating any
1036 * This can be handled by the eventual session reconnect.
1038 rc
= wait_for_compound_request(server
, num_rqst
, flags
,
1043 for (i
= 0; i
< num_rqst
; i
++) {
1044 credits
[i
].value
= 1;
1045 credits
[i
].instance
= instance
;
1049 * Make sure that we sign in the same order that we send on this socket
1050 * and avoid races inside tcp sendmsg code that could cause corruption
1054 mutex_lock(&server
->srv_mutex
);
1057 * All the parts of the compound chain belong obtained credits from the
1058 * same session. We can not use credits obtained from the previous
1059 * session to send this request. Check if there were reconnects after
1060 * we obtained credits and return -EAGAIN in such cases to let callers
1063 if (instance
!= server
->reconnect_instance
) {
1064 mutex_unlock(&server
->srv_mutex
);
1065 for (j
= 0; j
< num_rqst
; j
++)
1066 add_credits(server
, &credits
[j
], optype
);
1070 for (i
= 0; i
< num_rqst
; i
++) {
1071 midQ
[i
] = server
->ops
->setup_request(ses
, server
, &rqst
[i
]);
1072 if (IS_ERR(midQ
[i
])) {
1073 revert_current_mid(server
, i
);
1074 for (j
= 0; j
< i
; j
++)
1075 cifs_delete_mid(midQ
[j
]);
1076 mutex_unlock(&server
->srv_mutex
);
1078 /* Update # of requests on wire to server */
1079 for (j
= 0; j
< num_rqst
; j
++)
1080 add_credits(server
, &credits
[j
], optype
);
1081 return PTR_ERR(midQ
[i
]);
1084 midQ
[i
]->mid_state
= MID_REQUEST_SUBMITTED
;
1085 midQ
[i
]->optype
= optype
;
1087 * Invoke callback for every part of the compound chain
1088 * to calculate credits properly. Wake up this thread only when
1089 * the last element is received.
1091 if (i
< num_rqst
- 1)
1092 midQ
[i
]->callback
= cifs_compound_callback
;
1094 midQ
[i
]->callback
= cifs_compound_last_callback
;
1096 cifs_in_send_inc(server
);
1097 rc
= smb_send_rqst(server
, num_rqst
, rqst
, flags
);
1098 cifs_in_send_dec(server
);
1100 for (i
= 0; i
< num_rqst
; i
++)
1101 cifs_save_when_sent(midQ
[i
]);
1104 revert_current_mid(server
, num_rqst
);
1105 server
->sequence_number
-= 2;
1108 mutex_unlock(&server
->srv_mutex
);
1111 * If sending failed for some reason or it is an oplock break that we
1112 * will not receive a response to - return credits back
1114 if (rc
< 0 || (flags
& CIFS_NO_SRV_RSP
)) {
1115 for (i
= 0; i
< num_rqst
; i
++)
1116 add_credits(server
, &credits
[i
], optype
);
1121 * At this point the request is passed to the network stack - we assume
1122 * that any credits taken from the server structure on the client have
1123 * been spent and we can't return them back. Once we receive responses
1124 * we will collect credits granted by the server in the mid callbacks
1125 * and add those credits to the server structure.
1129 * Compounding is never used during session establish.
1131 if ((ses
->status
== CifsNew
) || (optype
& CIFS_NEG_OP
))
1132 smb311_update_preauth_hash(ses
, rqst
[0].rq_iov
,
1135 for (i
= 0; i
< num_rqst
; i
++) {
1136 rc
= wait_for_response(server
, midQ
[i
]);
1141 for (; i
< num_rqst
; i
++) {
1142 cifs_server_dbg(VFS
, "Cancelling wait for mid %llu cmd: %d\n",
1143 midQ
[i
]->mid
, le16_to_cpu(midQ
[i
]->command
));
1144 send_cancel(server
, &rqst
[i
], midQ
[i
]);
1145 spin_lock(&GlobalMid_Lock
);
1146 midQ
[i
]->mid_flags
|= MID_WAIT_CANCELLED
;
1147 if (midQ
[i
]->mid_state
== MID_REQUEST_SUBMITTED
) {
1148 midQ
[i
]->callback
= cifs_cancelled_callback
;
1149 cancelled_mid
[i
] = true;
1150 credits
[i
].value
= 0;
1152 spin_unlock(&GlobalMid_Lock
);
1156 for (i
= 0; i
< num_rqst
; i
++) {
1160 rc
= cifs_sync_mid_result(midQ
[i
], server
);
1162 /* mark this mid as cancelled to not free it below */
1163 cancelled_mid
[i
] = true;
1167 if (!midQ
[i
]->resp_buf
||
1168 midQ
[i
]->mid_state
!= MID_RESPONSE_RECEIVED
) {
1170 cifs_dbg(FYI
, "Bad MID state?\n");
1174 buf
= (char *)midQ
[i
]->resp_buf
;
1175 resp_iov
[i
].iov_base
= buf
;
1176 resp_iov
[i
].iov_len
= midQ
[i
]->resp_buf_size
+
1177 server
->vals
->header_preamble_size
;
1179 if (midQ
[i
]->large_buf
)
1180 resp_buf_type
[i
] = CIFS_LARGE_BUFFER
;
1182 resp_buf_type
[i
] = CIFS_SMALL_BUFFER
;
1184 rc
= server
->ops
->check_receive(midQ
[i
], server
,
1185 flags
& CIFS_LOG_ERROR
);
1187 /* mark it so buf will not be freed by cifs_delete_mid */
1188 if ((flags
& CIFS_NO_RSP_BUF
) == 0)
1189 midQ
[i
]->resp_buf
= NULL
;
1194 * Compounding is never used during session establish.
1196 if ((ses
->status
== CifsNew
) || (optype
& CIFS_NEG_OP
)) {
1198 .iov_base
= resp_iov
[0].iov_base
,
1199 .iov_len
= resp_iov
[0].iov_len
1201 smb311_update_preauth_hash(ses
, &iov
, 1);
1206 * This will dequeue all mids. After this it is important that the
1207 * demultiplex_thread will not process any of these mids any futher.
1208 * This is prevented above by using a noop callback that will not
1209 * wake this thread except for the very last PDU.
1211 for (i
= 0; i
< num_rqst
; i
++) {
1212 if (!cancelled_mid
[i
])
1213 cifs_delete_mid(midQ
[i
]);
1220 cifs_send_recv(const unsigned int xid
, struct cifs_ses
*ses
,
1221 struct smb_rqst
*rqst
, int *resp_buf_type
, const int flags
,
1222 struct kvec
*resp_iov
)
1224 return compound_send_recv(xid
, ses
, flags
, 1, rqst
, resp_buf_type
,
1229 SendReceive2(const unsigned int xid
, struct cifs_ses
*ses
,
1230 struct kvec
*iov
, int n_vec
, int *resp_buf_type
/* ret */,
1231 const int flags
, struct kvec
*resp_iov
)
1233 struct smb_rqst rqst
;
1234 struct kvec s_iov
[CIFS_MAX_IOV_SIZE
], *new_iov
;
1237 if (n_vec
+ 1 > CIFS_MAX_IOV_SIZE
) {
1238 new_iov
= kmalloc_array(n_vec
+ 1, sizeof(struct kvec
),
1241 /* otherwise cifs_send_recv below sets resp_buf_type */
1242 *resp_buf_type
= CIFS_NO_BUFFER
;
1248 /* 1st iov is a RFC1001 length followed by the rest of the packet */
1249 memcpy(new_iov
+ 1, iov
, (sizeof(struct kvec
) * n_vec
));
1251 new_iov
[0].iov_base
= new_iov
[1].iov_base
;
1252 new_iov
[0].iov_len
= 4;
1253 new_iov
[1].iov_base
+= 4;
1254 new_iov
[1].iov_len
-= 4;
1256 memset(&rqst
, 0, sizeof(struct smb_rqst
));
1257 rqst
.rq_iov
= new_iov
;
1258 rqst
.rq_nvec
= n_vec
+ 1;
1260 rc
= cifs_send_recv(xid
, ses
, &rqst
, resp_buf_type
, flags
, resp_iov
);
1261 if (n_vec
+ 1 > CIFS_MAX_IOV_SIZE
)
1267 SendReceive(const unsigned int xid
, struct cifs_ses
*ses
,
1268 struct smb_hdr
*in_buf
, struct smb_hdr
*out_buf
,
1269 int *pbytes_returned
, const int flags
)
1272 struct mid_q_entry
*midQ
;
1273 unsigned int len
= be32_to_cpu(in_buf
->smb_buf_length
);
1274 struct kvec iov
= { .iov_base
= in_buf
, .iov_len
= len
};
1275 struct smb_rqst rqst
= { .rq_iov
= &iov
, .rq_nvec
= 1 };
1276 struct cifs_credits credits
= { .value
= 1, .instance
= 0 };
1277 struct TCP_Server_Info
*server
;
1280 cifs_dbg(VFS
, "Null smb session\n");
1283 server
= ses
->server
;
1284 if (server
== NULL
) {
1285 cifs_dbg(VFS
, "Null tcp session\n");
1289 if (server
->tcpStatus
== CifsExiting
)
1292 /* Ensure that we do not send more than 50 overlapping requests
1293 to the same server. We may make this configurable later or
1296 if (len
> CIFSMaxBufSize
+ MAX_CIFS_HDR_SIZE
- 4) {
1297 cifs_server_dbg(VFS
, "Illegal length, greater than maximum frame, %d\n",
1302 rc
= wait_for_free_request(server
, flags
, &credits
.instance
);
1306 /* make sure that we sign in the same order that we send on this socket
1307 and avoid races inside tcp sendmsg code that could cause corruption
1310 mutex_lock(&server
->srv_mutex
);
1312 rc
= allocate_mid(ses
, in_buf
, &midQ
);
1314 mutex_unlock(&server
->srv_mutex
);
1315 /* Update # of requests on wire to server */
1316 add_credits(server
, &credits
, 0);
1320 rc
= cifs_sign_smb(in_buf
, server
, &midQ
->sequence_number
);
1322 mutex_unlock(&server
->srv_mutex
);
1326 midQ
->mid_state
= MID_REQUEST_SUBMITTED
;
1328 cifs_in_send_inc(server
);
1329 rc
= smb_send(server
, in_buf
, len
);
1330 cifs_in_send_dec(server
);
1331 cifs_save_when_sent(midQ
);
1334 server
->sequence_number
-= 2;
1336 mutex_unlock(&server
->srv_mutex
);
1341 rc
= wait_for_response(server
, midQ
);
1343 send_cancel(server
, &rqst
, midQ
);
1344 spin_lock(&GlobalMid_Lock
);
1345 if (midQ
->mid_state
== MID_REQUEST_SUBMITTED
) {
1346 /* no longer considered to be "in-flight" */
1347 midQ
->callback
= DeleteMidQEntry
;
1348 spin_unlock(&GlobalMid_Lock
);
1349 add_credits(server
, &credits
, 0);
1352 spin_unlock(&GlobalMid_Lock
);
1355 rc
= cifs_sync_mid_result(midQ
, server
);
1357 add_credits(server
, &credits
, 0);
1361 if (!midQ
->resp_buf
|| !out_buf
||
1362 midQ
->mid_state
!= MID_RESPONSE_RECEIVED
) {
1364 cifs_server_dbg(VFS
, "Bad MID state?\n");
1368 *pbytes_returned
= get_rfc1002_length(midQ
->resp_buf
);
1369 memcpy(out_buf
, midQ
->resp_buf
, *pbytes_returned
+ 4);
1370 rc
= cifs_check_receive(midQ
, server
, 0);
1372 cifs_delete_mid(midQ
);
1373 add_credits(server
, &credits
, 0);
1378 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1379 blocking lock to return. */
1382 send_lock_cancel(const unsigned int xid
, struct cifs_tcon
*tcon
,
1383 struct smb_hdr
*in_buf
,
1384 struct smb_hdr
*out_buf
)
1387 struct cifs_ses
*ses
= tcon
->ses
;
1388 LOCK_REQ
*pSMB
= (LOCK_REQ
*)in_buf
;
1390 /* We just modify the current in_buf to change
1391 the type of lock from LOCKING_ANDX_SHARED_LOCK
1392 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1393 LOCKING_ANDX_CANCEL_LOCK. */
1395 pSMB
->LockType
= LOCKING_ANDX_CANCEL_LOCK
|LOCKING_ANDX_LARGE_FILES
;
1397 pSMB
->hdr
.Mid
= get_next_mid(ses
->server
);
1399 return SendReceive(xid
, ses
, in_buf
, out_buf
,
1400 &bytes_returned
, 0);
1404 SendReceiveBlockingLock(const unsigned int xid
, struct cifs_tcon
*tcon
,
1405 struct smb_hdr
*in_buf
, struct smb_hdr
*out_buf
,
1406 int *pbytes_returned
)
1410 struct mid_q_entry
*midQ
;
1411 struct cifs_ses
*ses
;
1412 unsigned int len
= be32_to_cpu(in_buf
->smb_buf_length
);
1413 struct kvec iov
= { .iov_base
= in_buf
, .iov_len
= len
};
1414 struct smb_rqst rqst
= { .rq_iov
= &iov
, .rq_nvec
= 1 };
1415 unsigned int instance
;
1416 struct TCP_Server_Info
*server
;
1418 if (tcon
== NULL
|| tcon
->ses
== NULL
) {
1419 cifs_dbg(VFS
, "Null smb session\n");
1423 server
= ses
->server
;
1425 if (server
== NULL
) {
1426 cifs_dbg(VFS
, "Null tcp session\n");
1430 if (server
->tcpStatus
== CifsExiting
)
1433 /* Ensure that we do not send more than 50 overlapping requests
1434 to the same server. We may make this configurable later or
1437 if (len
> CIFSMaxBufSize
+ MAX_CIFS_HDR_SIZE
- 4) {
1438 cifs_tcon_dbg(VFS
, "Illegal length, greater than maximum frame, %d\n",
1443 rc
= wait_for_free_request(server
, CIFS_BLOCKING_OP
, &instance
);
1447 /* make sure that we sign in the same order that we send on this socket
1448 and avoid races inside tcp sendmsg code that could cause corruption
1451 mutex_lock(&server
->srv_mutex
);
1453 rc
= allocate_mid(ses
, in_buf
, &midQ
);
1455 mutex_unlock(&server
->srv_mutex
);
1459 rc
= cifs_sign_smb(in_buf
, server
, &midQ
->sequence_number
);
1461 cifs_delete_mid(midQ
);
1462 mutex_unlock(&server
->srv_mutex
);
1466 midQ
->mid_state
= MID_REQUEST_SUBMITTED
;
1467 cifs_in_send_inc(server
);
1468 rc
= smb_send(server
, in_buf
, len
);
1469 cifs_in_send_dec(server
);
1470 cifs_save_when_sent(midQ
);
1473 server
->sequence_number
-= 2;
1475 mutex_unlock(&server
->srv_mutex
);
1478 cifs_delete_mid(midQ
);
1482 /* Wait for a reply - allow signals to interrupt. */
1483 rc
= wait_event_interruptible(server
->response_q
,
1484 (!(midQ
->mid_state
== MID_REQUEST_SUBMITTED
)) ||
1485 ((server
->tcpStatus
!= CifsGood
) &&
1486 (server
->tcpStatus
!= CifsNew
)));
1488 /* Were we interrupted by a signal ? */
1489 if ((rc
== -ERESTARTSYS
) &&
1490 (midQ
->mid_state
== MID_REQUEST_SUBMITTED
) &&
1491 ((server
->tcpStatus
== CifsGood
) ||
1492 (server
->tcpStatus
== CifsNew
))) {
1494 if (in_buf
->Command
== SMB_COM_TRANSACTION2
) {
1495 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1496 blocking lock to return. */
1497 rc
= send_cancel(server
, &rqst
, midQ
);
1499 cifs_delete_mid(midQ
);
1503 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1504 to cause the blocking lock to return. */
1506 rc
= send_lock_cancel(xid
, tcon
, in_buf
, out_buf
);
1508 /* If we get -ENOLCK back the lock may have
1509 already been removed. Don't exit in this case. */
1510 if (rc
&& rc
!= -ENOLCK
) {
1511 cifs_delete_mid(midQ
);
1516 rc
= wait_for_response(server
, midQ
);
1518 send_cancel(server
, &rqst
, midQ
);
1519 spin_lock(&GlobalMid_Lock
);
1520 if (midQ
->mid_state
== MID_REQUEST_SUBMITTED
) {
1521 /* no longer considered to be "in-flight" */
1522 midQ
->callback
= DeleteMidQEntry
;
1523 spin_unlock(&GlobalMid_Lock
);
1526 spin_unlock(&GlobalMid_Lock
);
1529 /* We got the response - restart system call. */
1533 rc
= cifs_sync_mid_result(midQ
, server
);
1537 /* rcvd frame is ok */
1538 if (out_buf
== NULL
|| midQ
->mid_state
!= MID_RESPONSE_RECEIVED
) {
1540 cifs_tcon_dbg(VFS
, "Bad MID state?\n");
1544 *pbytes_returned
= get_rfc1002_length(midQ
->resp_buf
);
1545 memcpy(out_buf
, midQ
->resp_buf
, *pbytes_returned
+ 4);
1546 rc
= cifs_check_receive(midQ
, server
, 0);
1548 cifs_delete_mid(midQ
);
1549 if (rstart
&& rc
== -EACCES
)
1550 return -ERESTARTSYS
;