litmus-rt.git - The LITMUS^RT kernel.

The LITMUS^RT kernel.

Bjoern Brandenburg

about summary refs log tree commit diff stats

diff options

author	Richard Kuo <rkuo@codeaurora.org>	2011-10-31 19:53:38 -0400
committer	Linus Torvalds <torvalds@linux-foundation.org>	2011-11-01 10:34:20 -0400
commit	a7e79840991eac8da36f437c653ee4b8cfbdafdc (patch)
tree	a673266d06a67c7f4f32b0e048848e752b6bb441 /kernel/mutex-debug.c
parent	b7f3785fbb3df3307290d4c236ffaa7ad172b6ed (diff)

Hexagon: Add page table header files & etc.

Signed-off-by: Richard Kuo <rkuo@codeaurora.org> Signed-off-by: Linas Vepstas <linas@codeaurora.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Diffstat (limited to 'kernel/mutex-debug.c')

0 files changed, 0 insertions, 0 deletions

<sfrench@us.ibm.com> 2010-04-20 23:50:45 -0400 [CIFS] Neaten cERROR and cFYI macros, reduce text space' href='/cgit/cgit.cgi/litmus-rt-imx6.git/commit/fs/cifs/transport.c?h=wip-mc2-ver2&id=b6b38f704a8193daba520493ebdaf7e819962fc8'>b6b38f704a81

1
2
3

26
27
28

48
49
50

53
54

57
58
59

61
62

63
64

65
66
67

75
76

79
80
81

83
84

85
86
87

91
92
93

98
99

100
101

110
111
112

130
131
132

141
142

144
145
146

156
157
158

159
160

180
181

182
183
184

186
187

196
197

199
200

202
203

221
222

224
225

238
239

241
242
243

257
258

260
261

268
269
270

278
279

291
292

293
294

299
300

301
302

311
312

315
316
317

320
321
322

332
333
334

335
336
337

338
339

345
346

349
350

378
379

385
386

396
397

402
403

405
406

408
409

411
412

443
444

445
446

449
450
451

454
455
456

457
458

463
464

465
466
467

468
469
470

471
472
473

476
477

479
480
481

483
484
485

504
505

524
525
526

528
529

530
531

569
570

575
576

577
578
579

582
583
584

587
588
589

599
600
601

622
623

642
643

656
657

662
663
664

665
666
667

669
670
671

675
676
677

682
683

684
685

691
692
693

695
696

699
700
701

703
704

706
707

709
710

713
714
715

717
718
719

721
722
723

726
727

732
733

741
742

744
745

749
750

759
760
761

771
772

782
783

788
789

814
815
816

825
826

834
835
836

838
839

841
842
843

844
845

848
849
850

852
853
854

856
857
858

860
861
862

864
865
866

870
871
872

877
878

920
921

932
933
934

935
936

945
946

949
950

953
954

955
956

/*
 *   fs/cifs/transport.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *   Jeremy Allison (jra@samba.org) 2006.
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/fs.h>
#include <linux/list.h>
#include <linux/gfp.h>
#include <linux/wait.h>
#include <linux/net.h>
#include <linux/delay.h>
#include <linux/freezer.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
#include <linux/mempool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"

extern mempool_t *cifs_mid_poolp;

static void
wake_up_task(struct mid_q_entry *mid)
{
	wake_up_process(mid->callback_data);
}

struct mid_q_entry *
AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
{
	struct mid_q_entry *temp;

	if (server == NULL) {
		cERROR(1, "Null TCP session in AllocMidQEntry");
		return NULL;
	}

	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
	if (temp == NULL)
		return temp;
	else {
		memset(temp, 0, sizeof(struct mid_q_entry));
		temp->mid = smb_buffer->Mid;	/* always LE */
		temp->pid = current->pid;
		temp->command = cpu_to_le16(smb_buffer->Command);
		cFYI(1, "For smb_command %d", smb_buffer->Command);
	/*	do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
		/* when mid allocated can be before when sent */
		temp->when_alloc = jiffies;

		/*
		 * The default is for the mid to be synchronous, so the
		 * default callback just wakes up the current task.
		 */
		temp->callback = wake_up_task;
		temp->callback_data = current;
	}

	atomic_inc(&midCount);
	temp->mid_state = MID_REQUEST_ALLOCATED;
	return temp;
}

void
DeleteMidQEntry(struct mid_q_entry *midEntry)
{
#ifdef CONFIG_CIFS_STATS2
	unsigned long now;
#endif
	midEntry->mid_state = MID_FREE;
	atomic_dec(&midCount);
	if (midEntry->large_buf)
		cifs_buf_release(midEntry->resp_buf);
	else
		cifs_small_buf_release(midEntry->resp_buf);
#ifdef CONFIG_CIFS_STATS2
	now = jiffies;
	/* commands taking longer than one second are indications that
	   something is wrong, unless it is quite a slow link or server */
	if ((now - midEntry->when_alloc) > HZ) {
		if ((cifsFYI & CIFS_TIMER) &&
		    (midEntry->command != cpu_to_le16(SMB_COM_LOCKING_ANDX))) {
			printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %llu",
			       midEntry->command, midEntry->mid);
			printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
			       now - midEntry->when_alloc,
			       now - midEntry->when_sent,
			       now - midEntry->when_received);
		}
	}
#endif
	mempool_free(midEntry, cifs_mid_poolp);
}

static void
delete_mid(struct mid_q_entry *mid)
{
	spin_lock(&GlobalMid_Lock);
	list_del(&mid->qhead);
	spin_unlock(&GlobalMid_Lock);

	DeleteMidQEntry(mid);
}

static int
smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
{
	int rc = 0;
	int i = 0;
	struct msghdr smb_msg;
	__be32 *buf_len = (__be32 *)(iov[0].iov_base);
	unsigned int len = iov[0].iov_len;
	unsigned int total_len;
	int first_vec = 0;
	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
	struct socket *ssocket = server->ssocket;

	if (ssocket == NULL)
		return -ENOTSOCK; /* BB eventually add reconnect code here */

	smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
	smb_msg.msg_namelen = sizeof(struct sockaddr);
	smb_msg.msg_control = NULL;
	smb_msg.msg_controllen = 0;
	if (server->noblocksnd)
		smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
	else
		smb_msg.msg_flags = MSG_NOSIGNAL;

	total_len = 0;
	for (i = 0; i < n_vec; i++)
		total_len += iov[i].iov_len;

	cFYI(1, "Sending smb:  total_len %d", total_len);
	dump_smb(iov[0].iov_base, len);

	i = 0;
	while (total_len) {
		rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
				    n_vec - first_vec, total_len);
		if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
			i++;
			/*
			 * If blocking send we try 3 times, since each can block
			 * for 5 seconds. For nonblocking  we have to try more
			 * but wait increasing amounts of time allowing time for
			 * socket to clear.  The overall time we wait in either
			 * case to send on the socket is about 15 seconds.
			 * Similarly we wait for 15 seconds for a response from
			 * the server in SendReceive[2] for the server to send
			 * a response back for most types of requests (except
			 * SMB Write past end of file which can be slow, and
			 * blocking lock operations). NFS waits slightly longer
			 * than CIFS, but this can make it take longer for
			 * nonresponsive servers to be detected and 15 seconds
			 * is more than enough time for modern networks to
			 * send a packet.  In most cases if we fail to send
			 * after the retries we will kill the socket and
			 * reconnect which may clear the network problem.
			 */
			if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
				cERROR(1, "sends on sock %p stuck for 15 seconds",
				    ssocket);
				rc = -EAGAIN;
				break;
			}
			msleep(1 << i);
			continue;
		}
		if (rc < 0)
			break;

		if (rc == total_len) {
			total_len = 0;
			break;
		} else if (rc > total_len) {
			cERROR(1, "sent %d requested %d", rc, total_len);
			break;
		}
		if (rc == 0) {
			/* should never happen, letting socket clear before
			   retrying is our only obvious option here */
			cERROR(1, "tcp sent no data");
			msleep(500);
			continue;
		}
		total_len -= rc;
		/* the line below resets i */
		for (i = first_vec; i < n_vec; i++) {
			if (iov[i].iov_len) {
				if (rc > iov[i].iov_len) {
					rc -= iov[i].iov_len;
					iov[i].iov_len = 0;
				} else {
					iov[i].iov_base += rc;
					iov[i].iov_len -= rc;
					first_vec = i;
					break;
				}
			}
		}
		i = 0; /* in case we get ENOSPC on the next send */
	}

	if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
		cFYI(1, "partial send (%d remaining), terminating session",
			total_len);
		/* If we have only sent part of an SMB then the next SMB
		   could be taken as the remainder of this one.  We need
		   to kill the socket so the server throws away the partial
		   SMB */
		server->tcpStatus = CifsNeedReconnect;
	}

	if (rc < 0 && rc != -EINTR)
		cERROR(1, "Error %d sending data on socket to server", rc);
	else
		rc = 0;

	/* Don't want to modify the buffer as a side effect of this call. */
	*buf_len = cpu_to_be32(smb_buf_length);

	return rc;
}

int
smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
	 unsigned int smb_buf_length)
{
	struct kvec iov;

	iov.iov_base = smb_buffer;
	iov.iov_len = smb_buf_length + 4;

	return smb_sendv(server, &iov, 1);
}

static int
wait_for_free_credits(struct TCP_Server_Info *server, const int optype,
		      int *credits)
{
	int rc;

	spin_lock(&server->req_lock);
	if (optype == CIFS_ASYNC_OP) {
		/* oplock breaks must not be held up */
		server->in_flight++;
		*credits -= 1;
		spin_unlock(&server->req_lock);
		return 0;
	}

	while (1) {
		if (*credits <= 0) {
			spin_unlock(&server->req_lock);
			cifs_num_waiters_inc(server);
			rc = wait_event_killable(server->request_q,
						 has_credits(server, credits));
			cifs_num_waiters_dec(server);
			if (rc)
				return rc;
			spin_lock(&server->req_lock);
		} else {
			if (server->tcpStatus == CifsExiting) {
				spin_unlock(&server->req_lock);
				return -ENOENT;
			}

			/*
			 * Can not count locking commands against total
			 * as they are allowed to block on server.
			 */

			/* update # of requests on the wire to server */
			if (optype != CIFS_BLOCKING_OP) {
				*credits -= 1;
				server->in_flight++;
			}
			spin_unlock(&server->req_lock);
			break;
		}
	}
	return 0;
}

static int
wait_for_free_request(struct TCP_Server_Info *server, const int optype)
{
	return wait_for_free_credits(server, optype, get_credits_field(server));
}

static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
			struct mid_q_entry **ppmidQ)
{
	if (ses->server->tcpStatus == CifsExiting) {
		return -ENOENT;
	}

	if (ses->server->tcpStatus == CifsNeedReconnect) {
		cFYI(1, "tcp session dead - return to caller to retry");
		return -EAGAIN;
	}

	if (ses->status != CifsGood) {
		/* check if SMB session is bad because we are setting it up */
		if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
			(in_buf->Command != SMB_COM_NEGOTIATE))
			return -EAGAIN;
		/* else ok - we are setting up session */
	}
	*ppmidQ = AllocMidQEntry(in_buf, ses->server);
	if (*ppmidQ == NULL)
		return -ENOMEM;
	spin_lock(&GlobalMid_Lock);
	list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
	spin_unlock(&GlobalMid_Lock);
	return 0;
}

static int
wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
{
	int error;

	error = wait_event_freezekillable(server->response_q,
				    midQ->mid_state != MID_REQUEST_SUBMITTED);
	if (error < 0)
		return -ERESTARTSYS;

	return 0;
}

static int
cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
			 unsigned int nvec, struct mid_q_entry **ret_mid)
{
	int rc;
	struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
	struct mid_q_entry *mid;

	/* enable signing if server requires it */
	if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
		hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;

	mid = AllocMidQEntry(hdr, server);
	if (mid == NULL)
		return -ENOMEM;

	/* put it on the pending_mid_q */
	spin_lock(&GlobalMid_Lock);
	list_add_tail(&mid->qhead, &server->pending_mid_q);
	spin_unlock(&GlobalMid_Lock);

	rc = cifs_sign_smb2(iov, nvec, server, &mid->sequence_number);
	if (rc)
		delete_mid(mid);
	*ret_mid = mid;
	return rc;
}

/*
 * Send a SMB request and set the callback function in the mid to handle
 * the result. Caller is responsible for dealing with timeouts.
 */
int
cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
		unsigned int nvec, mid_receive_t *receive,
		mid_callback_t *callback, void *cbdata, bool ignore_pend)
{
	int rc;
	struct mid_q_entry *mid;

	rc = wait_for_free_request(server, ignore_pend ? CIFS_ASYNC_OP : 0);
	if (rc)
		return rc;

	mutex_lock(&server->srv_mutex);
	rc = cifs_setup_async_request(server, iov, nvec, &mid);
	if (rc) {
		mutex_unlock(&server->srv_mutex);
		cifs_add_credits(server, 1);
		wake_up(&server->request_q);
		return rc;
	}

	mid->receive = receive;
	mid->callback = callback;
	mid->callback_data = cbdata;
	mid->mid_state = MID_REQUEST_SUBMITTED;

	cifs_in_send_inc(server);
	rc = smb_sendv(server, iov, nvec);
	cifs_in_send_dec(server);
	cifs_save_when_sent(mid);
	mutex_unlock(&server->srv_mutex);

	if (rc)
		goto out_err;

	return rc;
out_err:
	delete_mid(mid);
	cifs_add_credits(server, 1);
	wake_up(&server->request_q);
	return rc;
}

/*
 *
 * Send an SMB Request.  No response info (other than return code)
 * needs to be parsed.
 *
 * flags indicate the type of request buffer and how long to wait
 * and whether to log NT STATUS code (error) before mapping it to POSIX error
 *
 */
int
SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
		 char *in_buf, int flags)
{
	int rc;
	struct kvec iov[1];
	int resp_buf_type;

	iov[0].iov_base = in_buf;
	iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
	flags |= CIFS_NO_RESP;
	rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
	cFYI(DBG2, "SendRcvNoRsp flags %d rc %d", flags, rc);

	return rc;
}

static int
cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
{
	int rc = 0;

	cFYI(1, "%s: cmd=%d mid=%llu state=%d", __func__,
	     le16_to_cpu(mid->command), mid->mid, mid->mid_state);

	spin_lock(&GlobalMid_Lock);
	switch (mid->mid_state) {
	case MID_RESPONSE_RECEIVED:
		spin_unlock(&GlobalMid_Lock);
		return rc;
	case MID_RETRY_NEEDED:
		rc = -EAGAIN;
		break;
	case MID_RESPONSE_MALFORMED:
		rc = -EIO;
		break;
	case MID_SHUTDOWN:
		rc = -EHOSTDOWN;
		break;
	default:
		list_del_init(&mid->qhead);
		cERROR(1, "%s: invalid mid state mid=%llu state=%d", __func__,
		       mid->mid, mid->mid_state);
		rc = -EIO;
	}
	spin_unlock(&GlobalMid_Lock);

	DeleteMidQEntry(mid);
	return rc;
}

/*
 * An NT cancel request header looks just like the original request except:
 *
 * The Command is SMB_COM_NT_CANCEL
 * The WordCount is zeroed out
 * The ByteCount is zeroed out
 *
 * This function mangles an existing request buffer into a
 * SMB_COM_NT_CANCEL request and then sends it.
 */
static int
send_nt_cancel(struct TCP_Server_Info *server, struct smb_hdr *in_buf,
		struct mid_q_entry *mid)
{
	int rc = 0;

	/* -4 for RFC1001 length and +2 for BCC field */
	in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4  + 2);
	in_buf->Command = SMB_COM_NT_CANCEL;
	in_buf->WordCount = 0;
	put_bcc(0, in_buf);

	mutex_lock(&server->srv_mutex);
	rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
	if (rc) {
		mutex_unlock(&server->srv_mutex);
		return rc;
	}
	rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
	mutex_unlock(&server->srv_mutex);

	cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
		in_buf->Mid, rc);

	return rc;
}

int
cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
		   bool log_error)
{
	unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;

	dump_smb(mid->resp_buf, min_t(u32, 92, len));

	/* convert the length into a more usable form */
	if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
		struct kvec iov;

		iov.iov_base = mid->resp_buf;
		iov.iov_len = len;
		/* FIXME: add code to kill session */
		if (cifs_verify_signature(&iov, 1, server,
					  mid->sequence_number + 1) != 0)
			cERROR(1, "Unexpected SMB signature");
	}

	/* BB special case reconnect tid and uid here? */
	return map_smb_to_linux_error(mid->resp_buf, log_error);
}

static int
cifs_setup_request(struct cifs_ses *ses, struct kvec *iov,
		   unsigned int nvec, struct mid_q_entry **ret_mid)
{
	int rc;
	struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
	struct mid_q_entry *mid;

	rc = allocate_mid(ses, hdr, &mid);
	if (rc)
		return rc;
	rc = cifs_sign_smb2(iov, nvec, ses->server, &mid->sequence_number);
	if (rc)
		delete_mid(mid);
	*ret_mid = mid;
	return rc;
}

int
SendReceive2(const unsigned int xid, struct cifs_ses *ses,
	     struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
	     const int flags)
{
	int rc = 0;
	int long_op;
	struct mid_q_entry *midQ;
	char *buf = iov[0].iov_base;

	long_op = flags & CIFS_TIMEOUT_MASK;

	*pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */

	if ((ses == NULL) || (ses->server == NULL)) {
		cifs_small_buf_release(buf);
		cERROR(1, "Null session");
		return -EIO;
	}

	if (ses->server->tcpStatus == CifsExiting) {
		cifs_small_buf_release(buf);
		return -ENOENT;
	}

	/*
	 * Ensure that we do not send more than 50 overlapping requests
	 * to the same server. We may make this configurable later or
	 * use ses->maxReq.
	 */

	rc = wait_for_free_request(ses->server, long_op);
	if (rc) {
		cifs_small_buf_release(buf);
		return rc;
	}

	/*
	 * Make sure that we sign in the same order that we send on this socket
	 * and avoid races inside tcp sendmsg code that could cause corruption
	 * of smb data.
	 */

	mutex_lock(&ses->server->srv_mutex);

	rc = cifs_setup_request(ses, iov, n_vec, &midQ);
	if (rc) {
		mutex_unlock(&ses->server->srv_mutex);
		cifs_small_buf_release(buf);
		/* Update # of requests on wire to server */
		cifs_add_credits(ses->server, 1);
		return rc;
	}

	midQ->mid_state = MID_REQUEST_SUBMITTED;
	cifs_in_send_inc(ses->server);
	rc = smb_sendv(ses->server, iov, n_vec);
	cifs_in_send_dec(ses->server);
	cifs_save_when_sent(midQ);

	mutex_unlock(&ses->server->srv_mutex);

	if (rc < 0) {
		cifs_small_buf_release(buf);
		goto out;
	}

	if (long_op == CIFS_ASYNC_OP) {
		cifs_small_buf_release(buf);
		goto out;
	}

	rc = wait_for_response(ses->server, midQ);
	if (rc != 0) {
		send_nt_cancel(ses->server, (struct smb_hdr *)buf, midQ);
		spin_lock(&GlobalMid_Lock);
		if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
			midQ->callback = DeleteMidQEntry;
			spin_unlock(&GlobalMid_Lock);
			cifs_small_buf_release(buf);
			cifs_add_credits(ses->server, 1);
			return rc;
		}
		spin_unlock(&GlobalMid_Lock);
	}

	cifs_small_buf_release(buf);

	rc = cifs_sync_mid_result(midQ, ses->server);
	if (rc != 0) {
		cifs_add_credits(ses->server, 1);
		return rc;
	}

	if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
		rc = -EIO;
		cFYI(1, "Bad MID state?");
		goto out;
	}

	buf = (char *)midQ->resp_buf;
	iov[0].iov_base = buf;
	iov[0].iov_len = get_rfc1002_length(buf) + 4;
	if (midQ->large_buf)
		*pRespBufType = CIFS_LARGE_BUFFER;
	else
		*pRespBufType = CIFS_SMALL_BUFFER;

	rc = cifs_check_receive(midQ, ses->server, flags & CIFS_LOG_ERROR);

	/* mark it so buf will not be freed by delete_mid */
	if ((flags & CIFS_NO_RESP) == 0)
		midQ->resp_buf = NULL;
out:
	delete_mid(midQ);
	cifs_add_credits(ses->server, 1);

	return rc;
}

int
SendReceive(const unsigned int xid, struct cifs_ses *ses,
	    struct smb_hdr *in_buf, struct smb_hdr *out_buf,
	    int *pbytes_returned, const int long_op)
{
	int rc = 0;
	struct mid_q_entry *midQ;

	if (ses == NULL) {
		cERROR(1, "Null smb session");
		return -EIO;
	}
	if (ses->server == NULL) {
		cERROR(1, "Null tcp session");
		return -EIO;
	}

	if (ses->server->tcpStatus == CifsExiting)
		return -ENOENT;

	/* Ensure that we do not send more than 50 overlapping requests
	   to the same server. We may make this configurable later or
	   use ses->maxReq */

	if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
			MAX_CIFS_HDR_SIZE - 4) {
		cERROR(1, "Illegal length, greater than maximum frame, %d",
			   be32_to_cpu(in_buf->smb_buf_length));
		return -EIO;
	}

	rc = wait_for_free_request(ses->server, long_op);
	if (rc)
		return rc;

	/* make sure that we sign in the same order that we send on this socket
	   and avoid races inside tcp sendmsg code that could cause corruption
	   of smb data */

	mutex_lock(&ses->server->srv_mutex);

	rc = allocate_mid(ses, in_buf, &midQ);
	if (rc) {
		mutex_unlock(&ses->server->srv_mutex);
		/* Update # of requests on wire to server */
		cifs_add_credits(ses->server, 1);
		return rc;
	}

	rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
	if (rc) {
		mutex_unlock(&ses->server->srv_mutex);
		goto out;
	}

	midQ->mid_state = MID_REQUEST_SUBMITTED;

	cifs_in_send_inc(ses->server);
	rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
	cifs_in_send_dec(ses->server);
	cifs_save_when_sent(midQ);
	mutex_unlock(&ses->server->srv_mutex);

	if (rc < 0)
		goto out;

	if (long_op == CIFS_ASYNC_OP)
		goto out;

	rc = wait_for_response(ses->server, midQ);
	if (rc != 0) {
		send_nt_cancel(ses->server, in_buf, midQ);
		spin_lock(&GlobalMid_Lock);
		if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
			/* no longer considered to be "in-flight" */
			midQ->callback = DeleteMidQEntry;
			spin_unlock(&GlobalMid_Lock);
			cifs_add_credits(ses->server, 1);
			return rc;
		}
		spin_unlock(&GlobalMid_Lock);
	}

	rc = cifs_sync_mid_result(midQ, ses->server);
	if (rc != 0) {
		cifs_add_credits(ses->server, 1);
		return rc;
	}

	if (!midQ->resp_buf || !out_buf ||
	    midQ->mid_state != MID_RESPONSE_RECEIVED) {
		rc = -EIO;
		cERROR(1, "Bad MID state?");
		goto out;
	}

	*pbytes_returned = get_rfc1002_length(midQ->resp_buf);
	memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
	rc = cifs_check_receive(midQ, ses->server, 0);
out:
	delete_mid(midQ);
	cifs_add_credits(ses->server, 1);

	return rc;
}

/* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
   blocking lock to return. */

static int
send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
			struct smb_hdr *in_buf,
			struct smb_hdr *out_buf)
{
	int bytes_returned;
	struct cifs_ses *ses = tcon->ses;
	LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;

	/* We just modify the current in_buf to change
	   the type of lock from LOCKING_ANDX_SHARED_LOCK
	   or LOCKING_ANDX_EXCLUSIVE_LOCK to
	   LOCKING_ANDX_CANCEL_LOCK. */

	pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
	pSMB->Timeout = 0;
	pSMB->hdr.Mid = GetNextMid(ses->server);

	return SendReceive(xid, ses, in_buf, out_buf,
			&bytes_returned, 0);
}

int
SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
	    struct smb_hdr *in_buf, struct smb_hdr *out_buf,
	    int *pbytes_returned)
{
	int rc = 0;
	int rstart = 0;
	struct mid_q_entry *midQ;
	struct cifs_ses *ses;

	if (tcon == NULL || tcon->ses == NULL) {
		cERROR(1, "Null smb session");
		return -EIO;
	}
	ses = tcon->ses;

	if (ses->server == NULL) {
		cERROR(1, "Null tcp session");
		return -EIO;
	}

	if (ses->server->tcpStatus == CifsExiting)
		return -ENOENT;

	/* Ensure that we do not send more than 50 overlapping requests
	   to the same server. We may make this configurable later or
	   use ses->maxReq */

	if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
			MAX_CIFS_HDR_SIZE - 4) {
		cERROR(1, "Illegal length, greater than maximum frame, %d",
			   be32_to_cpu(in_buf->smb_buf_length));
		return -EIO;
	}

	rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP);
	if (rc)
		return rc;

	/* make sure that we sign in the same order that we send on this socket
	   and avoid races inside tcp sendmsg code that could cause corruption
	   of smb data */

	mutex_lock(&ses->server->srv_mutex);

	rc = allocate_mid(ses, in_buf, &midQ);
	if (rc) {
		mutex_unlock(&ses->server->srv_mutex);
		return rc;
	}

	rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
	if (rc) {
		delete_mid(midQ);
		mutex_unlock(&ses->server->srv_mutex);
		return rc;
	}

	midQ->mid_state = MID_REQUEST_SUBMITTED;
	cifs_in_send_inc(ses->server);
	rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
	cifs_in_send_dec(ses->server);
	cifs_save_when_sent(midQ);
	mutex_unlock(&ses->server->srv_mutex);

	if (rc < 0) {
		delete_mid(midQ);
		return rc;
	}


context:
space:
mode: