static int
parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
		 char **_link_str)
{
	int rc;
	unsigned int link_len;
	const char *md5_str1;
	const char *link_str;
	u8 md5_hash[16];
	char md5_str2[34];

	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
		return -EINVAL;

	md5_str1 = (const char *)&buf[CIFS_MF_SYMLINK_MD5_OFFSET];
	link_str = (const char *)&buf[CIFS_MF_SYMLINK_LINK_OFFSET];

	rc = sscanf(buf, CIFS_MF_SYMLINK_LEN_FORMAT, &link_len);
	if (rc != 1)
		return -EINVAL;

	rc = symlink_hash(link_len, link_str, md5_hash);
	if (rc) {
		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
		return rc;
	}

	snprintf(md5_str2, sizeof(md5_str2),
		 CIFS_MF_SYMLINK_MD5_FORMAT,
		 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));

	if (strncmp(md5_str1, md5_str2, 17) != 0)
		return -EINVAL;

	if (_link_str) {
		*_link_str = kstrndup(link_str, link_len, GFP_KERNEL);
		if (!*_link_str)
			return -ENOMEM;
	}

	*_link_len = link_len;
	return 0;
}

static void __exit
exit_cifs(void)
{
	cifs_dbg(NOISY, "exit_cifs\n");
	unregister_filesystem(&cifs_fs_type);
	cifs_dfs_release_automount_timer();
#ifdef CONFIG_CIFS_ACL
	exit_cifs_idmap();
#endif
#ifdef CONFIG_CIFS_UPCALL
	unregister_key_type(&cifs_spnego_key_type);
#endif
	cifs_destroy_request_bufs();
	cifs_destroy_mids();
	cifs_destroy_inodecache();
	cifs_fscache_unregister();
	destroy_workqueue(cifsiod_wq);
	cifs_proc_clean();
}

int cifs_create(struct inode *inode, struct dentry *direntry, umode_t mode,
		bool excl)
{
	int rc;
	unsigned int xid = get_xid();
	/*
	 * BB below access is probably too much for mknod to request
	 *    but we have to do query and setpathinfo so requesting
	 *    less could fail (unless we want to request getatr and setatr
	 *    permissions (only).  At least for POSIX we do not have to
	 *    request so much.
	 */
	unsigned oflags = O_EXCL | O_CREAT | O_RDWR;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	struct cifs_fid fid;
	__u32 oplock;

	cifs_dbg(FYI, "cifs_create parent inode = 0x%p name is: %pd and dentry = 0x%p\n",
		 inode, direntry, direntry);

	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
	rc = PTR_ERR(tlink);
	if (IS_ERR(tlink))
		goto out_free_xid;

	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	if (server->ops->new_lease_key)
		server->ops->new_lease_key(&fid);

	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
			    &oplock, &fid);
	if (!rc && server->ops->close)
		server->ops->close(xid, tcon, &fid);

	cifs_put_tlink(tlink);
out_free_xid:
	free_xid(xid);
	return rc;
}

static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
				   unsigned long nr_segs, loff_t pos)
{
	struct inode *inode = file_inode(iocb->ki_filp);
	ssize_t written;
	int rc;

	written = generic_file_aio_write(iocb, iov, nr_segs, pos);

	if (CIFS_CACHE_WRITE(CIFS_I(inode)))
		return written;

	rc = filemap_fdatawrite(inode->i_mapping);
	if (rc)
		cifs_dbg(FYI, "cifs_file_aio_write: %d rc on %p inode\n",
			 rc, inode);

	return written;
}

static int
format_mf_symlink(u8 *buf, unsigned int buf_len, const char *link_str)
{
	int rc;
	unsigned int link_len;
	unsigned int ofs;
	u8 md5_hash[16];

	if (buf_len != CIFS_MF_SYMLINK_FILE_SIZE)
		return -EINVAL;

	link_len = strlen(link_str);

	if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
		return -ENAMETOOLONG;

	rc = symlink_hash(link_len, link_str, md5_hash);
	if (rc) {
		cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);
		return rc;
	}

	snprintf(buf, buf_len,
		 CIFS_MF_SYMLINK_LEN_FORMAT CIFS_MF_SYMLINK_MD5_FORMAT,
		 link_len,
		 CIFS_MF_SYMLINK_MD5_ARGS(md5_hash));

	ofs = CIFS_MF_SYMLINK_LINK_OFFSET;
	memcpy(buf + ofs, link_str, link_len);

	ofs += link_len;
	if (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
		buf[ofs] = '\n';
		ofs++;
	}

	while (ofs < CIFS_MF_SYMLINK_FILE_SIZE) {
		buf[ofs] = ' ';
		ofs++;
	}

	return 0;
}

static long cifs_ioctl_query_info(unsigned int xid, struct file *filep,
				  unsigned long p)
{
	struct inode *inode = file_inode(filep);
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
	struct dentry *dentry = filep->f_path.dentry;
	unsigned char *path;
	__le16 *utf16_path = NULL, root_path;
	int rc = 0;

	path = build_path_from_dentry(dentry);
	if (path == NULL)
		return -ENOMEM;

	cifs_dbg(FYI, "%s %s\n", __func__, path);

	if (!path[0]) {
		root_path = 0;
		utf16_path = &root_path;
	} else {
		utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb);
		if (!utf16_path) {
			rc = -ENOMEM;
			goto ici_exit;
		}
	}

	if (tcon->ses->server->ops->ioctl_query_info)
		rc = tcon->ses->server->ops->ioctl_query_info(
				xid, tcon, utf16_path,
				filep->private_data ? 0 : 1, p);
	else
		rc = -EOPNOTSUPP;

 ici_exit:
	if (utf16_path != &root_path)
		kfree(utf16_path);
	kfree(path);
	return rc;
}

struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
		const struct cifs_fid *cifsfid, u32 *pacllen)
{
	struct cifs_ntsd *pntsd = NULL;
	unsigned int xid;
	int rc;
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
		return ERR_CAST(tlink);

	xid = get_xid();
	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), cifsfid->netfid, &pntsd,
				pacllen);
	free_xid(xid);

	cifs_put_tlink(tlink);

	cifs_dbg(FYI, "%s: rc = %d ACL len %d\n", __func__, rc, *pacllen);
	if (rc)
		return ERR_PTR(rc);
	return pntsd;
}

static void mode_to_access_flags(umode_t mode, umode_t bits_to_use,
				__u32 *pace_flags)
{
	/* reset access mask */
	*pace_flags = 0x0;

	/* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */
	mode &= bits_to_use;

	/* check for R/W/X UGO since we do not know whose flags
	   is this but we have cleared all the bits sans RWX for
	   either user or group or other as per bits_to_use */
	if (mode & S_IRUGO)
		*pace_flags |= SET_FILE_READ_RIGHTS;
	if (mode & S_IWUGO)
		*pace_flags |= SET_FILE_WRITE_RIGHTS;
	if (mode & S_IXUGO)
		*pace_flags |= SET_FILE_EXEC_RIGHTS;

	cifs_dbg(NOISY, "mode: 0x%x, access flags now 0x%x\n",
		 mode, *pace_flags);
	return;
}

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 timeout)
{
	int rc = 0;
	struct mid_q_entry *midQ;

	if (ses == NULL) {
		cifs_dbg(VFS, "Null smb session\n");
		return -EIO;
	}
	if (ses->server == NULL) {
		cifs_dbg(VFS, "Null tcp session\n");
		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) {
		cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
			 be32_to_cpu(in_buf->smb_buf_length));
		return -EIO;
	}

	rc = wait_for_free_request(ses->server, timeout, 0);
	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 */
		add_credits(ses->server, 1, 0);
		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);

	if (rc < 0)
		ses->server->sequence_number -= 2;

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

	if (rc < 0)
		goto out;

	if (timeout == CIFS_ASYNC_OP)
		goto out;

	rc = wait_for_response(ses->server, midQ);
	if (rc != 0) {
		send_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);
			add_credits(ses->server, 1, 0);
			return rc;
		}
		spin_unlock(&GlobalMid_Lock);
	}

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

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

//.........这里部分代码省略.........

static int
smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
{
	int rc;
	struct kvec *iov = rqst->rq_iov;
	int n_vec = rqst->rq_nvec;
	unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
	unsigned long send_length;
	unsigned int i;
	size_t total_len = 0, sent;
	struct socket *ssocket = server->ssocket;
	int val = 1;

	if (ssocket == NULL)
		return -ENOTSOCK;

	/* sanity check send length */
	send_length = rqst_len(rqst);
	if (send_length != smb_buf_length + 4) {
		WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
			send_length, smb_buf_length);
		return -EIO;
	}

	cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
	dump_smb(iov[0].iov_base, iov[0].iov_len);

	/* cork the socket */
	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
				(char *)&val, sizeof(val));

	rc = smb_send_kvec(server, iov, n_vec, &sent);
	if (rc < 0)
		goto uncork;

	total_len += sent;

	/* now walk the page array and send each page in it */
	for (i = 0; i < rqst->rq_npages; i++) {
		struct kvec p_iov;

		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
		rc = smb_send_kvec(server, &p_iov, 1, &sent);
		kunmap(rqst->rq_pages[i]);
		if (rc < 0)
			break;

		total_len += sent;
	}

uncork:
	/* uncork it */
	val = 0;
	kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
				(char *)&val, sizeof(val));

	if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
		cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
			 smb_buf_length + 4, 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)
		cifs_dbg(VFS, "Error %d sending data on socket to server\n",
			 rc);
	else
		rc = 0;

	return rc;
}

/*
 * Create a vfsmount that we can automount
 */
static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
{
	struct dfs_info3_param *referrals = NULL;
	unsigned int num_referrals = 0;
	struct cifs_sb_info *cifs_sb;
	struct cifs_ses *ses;
	char *full_path;
	unsigned int xid;
	int i;
	int rc;
	struct vfsmount *mnt;
	struct tcon_link *tlink;

	cifs_dbg(FYI, "in %s\n", __func__);
	BUG_ON(IS_ROOT(mntpt));

	/*
	 * The MSDFS spec states that paths in DFS referral requests and
	 * responses must be prefixed by a single '\' character instead of
	 * the double backslashes usually used in the UNC. This function
	 * gives us the latter, so we must adjust the result.
	 */
	mnt = ERR_PTR(-ENOMEM);
	full_path = build_path_from_dentry(mntpt);
	if (full_path == NULL)
		goto cdda_exit;

	cifs_sb = CIFS_SB(d_inode(mntpt)->i_sb);
	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink)) {
		mnt = ERR_CAST(tlink);
		goto free_full_path;
	}
	ses = tlink_tcon(tlink)->ses;

	xid = get_xid();
	rc = get_dfs_path(xid, ses, full_path + 1, cifs_sb->local_nls,
		&num_referrals, &referrals,
		cifs_remap(cifs_sb));
	free_xid(xid);

	cifs_put_tlink(tlink);

	mnt = ERR_PTR(-ENOENT);
	for (i = 0; i < num_referrals; i++) {
		int len;
		dump_referral(referrals + i);
		/* connect to a node */
		len = strlen(referrals[i].node_name);
		if (len < 2) {
			cifs_dbg(VFS, "%s: Net Address path too short: %s\n",
				 __func__, referrals[i].node_name);
			mnt = ERR_PTR(-EINVAL);
			break;
		}
		mnt = cifs_dfs_do_refmount(cifs_sb,
				full_path, referrals + i);
		cifs_dbg(FYI, "%s: cifs_dfs_do_refmount:%s , mnt:%p\n",
			 __func__, referrals[i].node_name, mnt);
		if (!IS_ERR(mnt))
			goto success;
	}

	/* no valid submounts were found; return error from get_dfs_path() by
	 * preference */
	if (rc != 0)
		mnt = ERR_PTR(rc);

success:
	free_dfs_info_array(referrals, num_referrals);
free_full_path:
	kfree(full_path);
cdda_exit:
	cifs_dbg(FYI, "leaving %s\n" , __func__);
	return mnt;
}

static int
smb2_open_op_close(const unsigned int xid, struct cifs_tcon *tcon,
		   struct cifs_sb_info *cifs_sb, const char *full_path,
		   __u32 desired_access, __u32 create_disposition,
		   __u32 create_options, void *data, int command)
{
	int rc, tmprc = 0;
	__le16 *utf16_path;
	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
	struct cifs_open_parms oparms;
	struct cifs_fid fid;

	utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
	if (!utf16_path)
		return -ENOMEM;

	oparms.tcon = tcon;
	oparms.desired_access = desired_access;
	oparms.share_access = FILE_SHARE_ALL;
	oparms.disposition = create_disposition;
	oparms.create_options = create_options;
	oparms.fid = &fid;
	oparms.reconnect = false;

	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL);
	if (rc) {
		kfree(utf16_path);
		return rc;
	}

	switch (command) {
	case SMB2_OP_DELETE:
		break;
	case SMB2_OP_QUERY_INFO:
		tmprc = SMB2_query_info(xid, tcon, fid.persistent_fid,
					fid.volatile_fid,
					(struct smb2_file_all_info *)data);
		break;
	case SMB2_OP_MKDIR:
		/*
		 * Directories are created through parameters in the
		 * SMB2_open() call.
		 */
		break;
	case SMB2_OP_RENAME:
		tmprc = SMB2_rename(xid, tcon, fid.persistent_fid,
				    fid.volatile_fid, (__le16 *)data);
		break;
	case SMB2_OP_HARDLINK:
		tmprc = SMB2_set_hardlink(xid, tcon, fid.persistent_fid,
					  fid.volatile_fid, (__le16 *)data);
		break;
	case SMB2_OP_SET_EOF:
		tmprc = SMB2_set_eof(xid, tcon, fid.persistent_fid,
				     fid.volatile_fid, current->tgid,
				     (__le64 *)data, false);
		break;
	case SMB2_OP_SET_INFO:
		tmprc = SMB2_set_info(xid, tcon, fid.persistent_fid,
				      fid.volatile_fid,
				      (FILE_BASIC_INFO *)data);
		break;
	default:
		cifs_dbg(VFS, "Invalid command\n");
		break;
	}

	rc = SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
	if (tmprc)
		rc = tmprc;
	kfree(utf16_path);
	return rc;
}

/*
 * Returns the pointer to the beginning of the data area. Length of the data
 * area and the offset to it (from the beginning of the smb are also returned.
 */
char *
smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
{
	*off = 0;
	*len = 0;

	/* error responses do not have data area */
	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
	    (((struct smb2_err_rsp *)hdr)->StructureSize) ==
						SMB2_ERROR_STRUCTURE_SIZE2)
		return NULL;

	/*
	 * Following commands have data areas so we have to get the location
	 * of the data buffer offset and data buffer length for the particular
	 * command.
	 */
	switch (hdr->Command) {
	case SMB2_NEGOTIATE:
		*off = le16_to_cpu(
		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
		*len = le16_to_cpu(
		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
		break;
	case SMB2_SESSION_SETUP:
		*off = le16_to_cpu(
		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
		*len = le16_to_cpu(
		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
		break;
	case SMB2_CREATE:
		*off = le32_to_cpu(
		    ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
		*len = le32_to_cpu(
		    ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
		break;
	case SMB2_QUERY_INFO:
		*off = le16_to_cpu(
		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
		*len = le32_to_cpu(
		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
		break;
	case SMB2_READ:
		*off = ((struct smb2_read_rsp *)hdr)->DataOffset;
		*len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
		break;
	case SMB2_QUERY_DIRECTORY:
		*off = le16_to_cpu(
		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
		*len = le32_to_cpu(
		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
		break;
	case SMB2_IOCTL:
		*off = le32_to_cpu(
		  ((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
		*len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount);
		break;
	case SMB2_CHANGE_NOTIFY:
	default:
		/* BB FIXME for unimplemented cases above */
		cifs_dbg(VFS, "no length check for command\n");
		break;
	}

	/*
	 * Invalid length or offset probably means data area is invalid, but
	 * we have little choice but to ignore the data area in this case.
	 */
	if (*off > 4096) {
		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
		*len = 0;
		*off = 0;
	} else if (*off < 0) {
		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
			 *off);
		*off = 0;
		*len = 0;
	} else if (*len < 0) {
		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
			 *len);
		*len = 0;
	} else if (*len > 128 * 1024) {
		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
		*len = 0;
	}

	/* return pointer to beginning of data area, ie offset from SMB start */
	if ((*off != 0) && (*len != 0))
		return hdr->ProtocolId + *off;
	else
		return NULL;
}

struct dentry *
cifs_lookup(struct inode *parent_dir_inode, struct dentry *direntry,
	    unsigned int flags)
{
	unsigned int xid;
	int rc = 0; /* to get around spurious gcc warning, set to zero here */
	struct cifs_sb_info *cifs_sb;
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	struct inode *newInode = NULL;
	char *full_path = NULL;

	xid = get_xid();

	cifs_dbg(FYI, "parent inode = 0x%p name is: %s and dentry = 0x%p\n",
		 parent_dir_inode, direntry->d_name.name, direntry);

	/* check whether path exists */

	cifs_sb = CIFS_SB(parent_dir_inode->i_sb);
	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink)) {
		free_xid(xid);
		return (struct dentry *)tlink;
	}
	pTcon = tlink_tcon(tlink);

	rc = check_name(direntry);
	if (rc)
		goto lookup_out;

	/* can not grab the rename sem here since it would
	deadlock in the cases (beginning of sys_rename itself)
	in which we already have the sb rename sem */
	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto lookup_out;
	}

	if (direntry->d_inode != NULL) {
		cifs_dbg(FYI, "non-NULL inode in lookup\n");
	} else {
		cifs_dbg(FYI, "NULL inode in lookup\n");
	}
	cifs_dbg(FYI, "Full path: %s inode = 0x%p\n",
		 full_path, direntry->d_inode);

	if (pTcon->unix_ext) {
		rc = cifs_get_inode_info_unix(&newInode, full_path,
					      parent_dir_inode->i_sb, xid);
	} else {
		rc = cifs_get_inode_info(&newInode, full_path, NULL,
				parent_dir_inode->i_sb, xid, NULL);
	}

	if ((rc == 0) && (newInode != NULL)) {
		d_add(direntry, newInode);
		/* since paths are not looked up by component - the parent
		   directories are presumed to be good here */
		renew_parental_timestamps(direntry);

	} else if (rc == -ENOENT) {
		rc = 0;
		direntry->d_time = jiffies;
		d_add(direntry, NULL);
	/*	if it was once a directory (but how can we tell?) we could do
		shrink_dcache_parent(direntry); */
	} else if (rc != -EACCES) {
		cifs_dbg(VFS, "Unexpected lookup error %d\n", rc);
		/* We special case check for Access Denied - since that
		is a common return code */
	}

lookup_out:
	kfree(full_path);
	cifs_put_tlink(tlink);
	free_xid(xid);
	return ERR_PTR(rc);
}

void
generate_smb3signingkey(struct TCP_Server_Info *server)
{
	unsigned char zero = 0x0;
	__u8 i[4] = {0, 0, 0, 1};
	__u8 L[4] = {0, 0, 0, 128};
	int rc = 0;
	unsigned char prfhash[SMB2_HMACSHA256_SIZE];
	unsigned char *hashptr = prfhash;

	memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
	memset(server->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE);

	rc = smb3_crypto_shash_allocate(server);
	if (rc) {
		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_setkey(server->secmech.hmacsha256,
		server->session_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
				i, 4);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
				"SMB2AESCMAC", 12);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
				&zero, 1);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
				"SmbSign", 8);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
				L, 4);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
				hashptr);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
		goto smb3signkey_ret;
	}

	memcpy(server->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE);

smb3signkey_ret:
	return;
}

int
cifs_atomic_open(struct inode *inode, struct dentry *direntry,
		 struct file *file, unsigned oflags, umode_t mode,
		 int *opened)
{
	int rc;
	unsigned int xid;
	struct tcon_link *tlink;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;
	struct cifs_fid fid;
	struct cifs_pending_open open;
	__u32 oplock;
	struct cifsFileInfo *file_info;

	/*
	 * Posix open is only called (at lookup time) for file create now. For
	 * opens (rather than creates), because we do not know if it is a file
	 * or directory yet, and current Samba no longer allows us to do posix
	 * open on dirs, we could end up wasting an open call on what turns out
	 * to be a dir. For file opens, we wait to call posix open till
	 * cifs_open.  It could be added to atomic_open in the future but the
	 * performance tradeoff of the extra network request when EISDIR or
	 * EACCES is returned would have to be weighed against the 50% reduction
	 * in network traffic in the other paths.
	 */
	if (!(oflags & O_CREAT)) {
		struct dentry *res;

		/*
		 * Check for hashed negative dentry. We have already revalidated
		 * the dentry and it is fine. No need to perform another lookup.
		 */
		if (!d_unhashed(direntry))
			return -ENOENT;

		res = cifs_lookup(inode, direntry, 0);
		if (IS_ERR(res))
			return PTR_ERR(res);

		return finish_no_open(file, res);
	}

	rc = check_name(direntry);
	if (rc)
		return rc;

	xid = get_xid();

	cifs_dbg(FYI, "parent inode = 0x%p name is: %s and dentry = 0x%p\n",
		 inode, direntry->d_name.name, direntry);

	tlink = cifs_sb_tlink(CIFS_SB(inode->i_sb));
	if (IS_ERR(tlink)) {
		rc = PTR_ERR(tlink);
		goto out_free_xid;
	}

	tcon = tlink_tcon(tlink);
	server = tcon->ses->server;

	if (server->ops->new_lease_key)
		server->ops->new_lease_key(&fid);

	cifs_add_pending_open(&fid, tlink, &open);

	rc = cifs_do_create(inode, direntry, xid, tlink, oflags, mode,
			    &oplock, &fid, opened);

	if (rc) {
		cifs_del_pending_open(&open);
		goto out;
	}

	rc = finish_open(file, direntry, generic_file_open, opened);
	if (rc) {
		if (server->ops->close)
			server->ops->close(xid, tcon, &fid);
		cifs_del_pending_open(&open);
		goto out;
	}

	file_info = cifs_new_fileinfo(&fid, file, tlink, oplock);
	if (file_info == NULL) {
		if (server->ops->close)
			server->ops->close(xid, tcon, &fid);
		cifs_del_pending_open(&open);
		fput(file);
		rc = -ENOMEM;
	}

out:
	cifs_put_tlink(tlink);
out_free_xid:
	free_xid(xid);
	return rc;
}

int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
		dev_t device_number)
{
	int rc = -EPERM;
	unsigned int xid;
	int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
	struct cifs_sb_info *cifs_sb;
	struct tcon_link *tlink;
	struct cifs_tcon *pTcon;
	struct cifs_io_parms io_parms;
	char *full_path = NULL;
	struct inode *newinode = NULL;
	int oplock = 0;
	u16 fileHandle;
	FILE_ALL_INFO *buf = NULL;
	unsigned int bytes_written;
	struct win_dev *pdev;

	if (!old_valid_dev(device_number))
		return -EINVAL;

	cifs_sb = CIFS_SB(inode->i_sb);
	tlink = cifs_sb_tlink(cifs_sb);
	if (IS_ERR(tlink))
		return PTR_ERR(tlink);

	pTcon = tlink_tcon(tlink);

	xid = get_xid();

	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto mknod_out;
	}

	if (pTcon->unix_ext) {
		struct cifs_unix_set_info_args args = {
			.mode	= mode & ~current_umask(),
			.ctime	= NO_CHANGE_64,
			.atime	= NO_CHANGE_64,
			.mtime	= NO_CHANGE_64,
			.device	= device_number,
		};
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
			args.uid = current_fsuid();
			args.gid = current_fsgid();
		} else {
			args.uid = INVALID_UID; /* no change */
			args.gid = INVALID_GID; /* no change */
		}
		rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, &args,
					    cifs_sb->local_nls,
					    cifs_sb->mnt_cifs_flags &
						CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (rc)
			goto mknod_out;

		rc = cifs_get_inode_info_unix(&newinode, full_path,
						inode->i_sb, xid);

		if (rc == 0)
			d_instantiate(direntry, newinode);
		goto mknod_out;
	}

	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
		goto mknod_out;


	cifs_dbg(FYI, "sfu compat create special file\n");

	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
	if (buf == NULL) {
		kfree(full_path);
		rc = -ENOMEM;
		free_xid(xid);
		return rc;
	}

	if (backup_cred(cifs_sb))
		create_options |= CREATE_OPEN_BACKUP_INTENT;

	rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_CREATE,
			 GENERIC_WRITE, create_options,
			 &fileHandle, &oplock, buf, cifs_sb->local_nls,
			 cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc)
		goto mknod_out;

	/* BB Do not bother to decode buf since no local inode yet to put
	 * timestamps in, but we can reuse it safely */

	pdev = (struct win_dev *)buf;
	io_parms.netfid = fileHandle;
	io_parms.pid = current->tgid;
	io_parms.tcon = pTcon;
	io_parms.offset = 0;
	io_parms.length = sizeof(struct win_dev);
	if (S_ISCHR(mode)) {
//.........这里部分代码省略.........

int
smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
	int i, rc;
	unsigned char smb3_signature[SMB2_CMACAES_SIZE];
	unsigned char *sigptr = smb3_signature;
	struct kvec *iov = rqst->rq_iov;
	int n_vec = rqst->rq_nvec;
	struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;

	memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
	memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);

	rc = crypto_shash_setkey(server->secmech.cmacaes,
		server->smb3signingkey, SMB2_CMACAES_SIZE);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
		return rc;
	}

	/*
	 * we already allocate sdesccmacaes when we init smb3 signing key,
	 * so unlike smb2 case we do not have to check here if secmech are
	 * initialized
	 */
	rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
		return rc;
	}

	for (i = 0; i < n_vec; i++) {
		if (iov[i].iov_len == 0)
			continue;
		if (iov[i].iov_base == NULL) {
			cifs_dbg(VFS, "null iovec entry");
			return -EIO;
		}
		/*
		 * The first entry includes a length field (which does not get
		 * signed that occupies the first 4 bytes before the header).
		 */
		if (i == 0) {
			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
				break; /* nothing to sign or corrupt header */
			rc =
			crypto_shash_update(
				&server->secmech.sdesccmacaes->shash,
				iov[i].iov_base + 4, iov[i].iov_len - 4);
		} else {
			rc =
			crypto_shash_update(
				&server->secmech.sdesccmacaes->shash,
				iov[i].iov_base, iov[i].iov_len);
		}
		if (rc) {
			cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
							__func__);
			return rc;
		}
	}

	/* now hash over the rq_pages array */
	for (i = 0; i < rqst->rq_npages; i++) {
		struct kvec p_iov;

		cifs_rqst_page_to_kvec(rqst, i, &p_iov);
		crypto_shash_update(&server->secmech.sdesccmacaes->shash,
					p_iov.iov_base, p_iov.iov_len);
		kunmap(rqst->rq_pages[i]);
	}

	rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
						sigptr);
	if (rc)
		cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);

	memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);

	return rc;
}

/* Note: caller must free return buffer */
char *
build_path_from_dentry(struct dentry *direntry)
{
	struct dentry *temp;
	int namelen;
	int dfsplen;
	int pplen = 0;
	char *full_path;
	char dirsep;
	struct cifs_sb_info *cifs_sb = CIFS_SB(direntry->d_sb);
	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
	unsigned seq;

	dirsep = CIFS_DIR_SEP(cifs_sb);
	if (tcon->Flags & SMB_SHARE_IS_IN_DFS)
		dfsplen = strnlen(tcon->treeName, MAX_TREE_SIZE + 1);
	else
		dfsplen = 0;

	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH)
		pplen = cifs_sb->prepath ? strlen(cifs_sb->prepath) + 1 : 0;

cifs_bp_rename_retry:
	namelen = dfsplen + pplen;
	seq = read_seqbegin(&rename_lock);
	rcu_read_lock();
	for (temp = direntry; !IS_ROOT(temp);) {
		namelen += (1 + temp->d_name.len);
		temp = temp->d_parent;
		if (temp == NULL) {
			cifs_dbg(VFS, "corrupt dentry\n");
			rcu_read_unlock();
			return NULL;
		}
	}
	rcu_read_unlock();

	full_path = kmalloc(namelen+1, GFP_KERNEL);
	if (full_path == NULL)
		return full_path;
	full_path[namelen] = 0;	/* trailing null */
	rcu_read_lock();
	for (temp = direntry; !IS_ROOT(temp);) {
		spin_lock(&temp->d_lock);
		namelen -= 1 + temp->d_name.len;
		if (namelen < 0) {
			spin_unlock(&temp->d_lock);
			break;
		} else {
			full_path[namelen] = dirsep;
			strncpy(full_path + namelen + 1, temp->d_name.name,
				temp->d_name.len);
			cifs_dbg(FYI, "name: %s\n", full_path + namelen);
		}
		spin_unlock(&temp->d_lock);
		temp = temp->d_parent;
		if (temp == NULL) {
			cifs_dbg(VFS, "corrupt dentry\n");
			rcu_read_unlock();
			kfree(full_path);
			return NULL;
		}
	}
	rcu_read_unlock();
	if (namelen != dfsplen + pplen || read_seqretry(&rename_lock, seq)) {
		cifs_dbg(FYI, "did not end path lookup where expected. namelen=%ddfsplen=%d\n",
			 namelen, dfsplen);
		/* presumably this is only possible if racing with a rename
		of one of the parent directories  (we can not lock the dentries
		above us to prevent this, but retrying should be harmless) */
		kfree(full_path);
		goto cifs_bp_rename_retry;
	}
	/* DIR_SEP already set for byte  0 / vs \ but not for
	   subsequent slashes in prepath which currently must
	   be entered the right way - not sure if there is an alternative
	   since the '\' is a valid posix character so we can not switch
	   those safely to '/' if any are found in the middle of the prepath */
	/* BB test paths to Windows with '/' in the midst of prepath */

	if (pplen) {
		int i;

		cifs_dbg(FYI, "using cifs_sb prepath <%s>\n", cifs_sb->prepath);
		memcpy(full_path+dfsplen+1, cifs_sb->prepath, pplen-1);
		full_path[dfsplen] = '\\';
		for (i = 0; i < pplen-1; i++)
			if (full_path[dfsplen+1+i] == '/')
				full_path[dfsplen+1+i] = CIFS_DIR_SEP(cifs_sb);
	}

	if (dfsplen) {
		strncpy(full_path, tcon->treeName, dfsplen);
		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_POSIX_PATHS) {
			int i;
			for (i = 0; i < dfsplen; i++) {
				if (full_path[i] == '\\')
					full_path[i] = '/';
			}
//.........这里部分代码省略.........

static int
initiate_cifs_search(const unsigned int xid, struct file *file)
{
	__u16 search_flags;
	int rc = 0;
	char *full_path = NULL;
	struct cifsFileInfo *cifsFile;
	struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
	struct tcon_link *tlink = NULL;
	struct cifs_tcon *tcon;
	struct TCP_Server_Info *server;

	if (file->private_data == NULL) {
		tlink = cifs_sb_tlink(cifs_sb);
		if (IS_ERR(tlink))
			return PTR_ERR(tlink);

		cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
		if (cifsFile == NULL) {
			rc = -ENOMEM;
			goto error_exit;
		}
		file->private_data = cifsFile;
		cifsFile->tlink = cifs_get_tlink(tlink);
		tcon = tlink_tcon(tlink);
	} else {
		cifsFile = file->private_data;
		tcon = tlink_tcon(cifsFile->tlink);
	}

	server = tcon->ses->server;

	if (!server->ops->query_dir_first) {
		rc = -ENOSYS;
		goto error_exit;
	}

	cifsFile->invalidHandle = true;
	cifsFile->srch_inf.endOfSearch = false;

	full_path = build_path_from_dentry(file->f_path.dentry);
	if (full_path == NULL) {
		rc = -ENOMEM;
		goto error_exit;
	}

	cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);

ffirst_retry:
	/* test for Unix extensions */
	/* but now check for them on the share/mount not on the SMB session */
	/* if (cap_unix(tcon->ses) { */
	if (tcon->unix_ext)
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
	else if ((tcon->ses->capabilities &
		  tcon->ses->server->vals->cap_nt_find) == 0) {
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
	} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
	} else /* not srvinos - BB fixme add check for backlevel? */ {
		cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
	}

	search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
	if (backup_cred(cifs_sb))
		search_flags |= CIFS_SEARCH_BACKUP_SEARCH;

	rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
					  &cifsFile->fid, search_flags,
					  &cifsFile->srch_inf);

	if (rc == 0)
		cifsFile->invalidHandle = false;
	/* BB add following call to handle readdir on new NTFS symlink errors
	else if STATUS_STOPPED_ON_SYMLINK
		call get_symlink_reparse_path and retry with new path */
	else if ((rc == -EOPNOTSUPP) &&
		(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
		goto ffirst_retry;
	}
error_exit:
	kfree(full_path);
	cifs_put_tlink(tlink);
	return rc;
}