C++ GetXid函数代码示例

static int
cifs_statfs(struct super_block *sb, struct kstatfs *buf)
{
	int xid; 
	int rc = -EOPNOTSUPP;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	xid = GetXid();

	cifs_sb = CIFS_SB(sb);
	pTcon = cifs_sb->tcon;

	buf->f_type = CIFS_MAGIC_NUMBER;

	/* instead could get the real value via SMB_QUERY_FS_ATTRIBUTE_INFO */
	buf->f_namelen = PATH_MAX; /* PATH_MAX may be too long - it would 
				      presumably be total path, but note
				      that some servers (includinng Samba 3)
				      have a shorter maximum path */
	buf->f_files = 0;	/* undefined */
	buf->f_ffree = 0;	/* unlimited */

#ifdef CONFIG_CIFS_EXPERIMENTAL
/* BB we could add a second check for a QFS Unix capability bit */
/* BB FIXME check CIFS_POSIX_EXTENSIONS Unix cap first FIXME BB */
    if ((pTcon->ses->capabilities & CAP_UNIX) && (CIFS_POSIX_EXTENSIONS &
			le64_to_cpu(pTcon->fsUnixInfo.Capability)))
	    rc = CIFSSMBQFSPosixInfo(xid, pTcon, buf);

    /* Only need to call the old QFSInfo if failed
    on newer one */
    if(rc)
#endif /* CIFS_EXPERIMENTAL */
	rc = CIFSSMBQFSInfo(xid, pTcon, buf);

	/*     
	   int f_type;
	   __fsid_t f_fsid;
	   int f_namelen;  */
	/* BB get from info in tcon struct at mount time call to QFSAttrInfo */
	FreeXid(xid);
	return 0;		/* always return success? what if volume is no
				   longer available? */
}

ssize_t cifs_listxattr(struct dentry * direntry, char * data, size_t buf_size)
{
	ssize_t rc = -EOPNOTSUPP;
#ifdef CONFIG_CIFS_XATTR
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	struct super_block * sb;
	char * full_path;

	if(direntry == NULL)
		return -EIO;
	if(direntry->d_inode == NULL)
		return -EIO;
	sb = direntry->d_inode->i_sb;
	if(sb == NULL)
		return -EIO;
	xid = GetXid();

	cifs_sb = CIFS_SB(sb);
	pTcon = cifs_sb->tcon;

	down(&sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&sb->s_vfs_rename_sem);
	if(full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}
	/* return dos attributes as pseudo xattr */
	/* return alt name if available as pseudo attr */

	/* if proc/fs/cifs/streamstoxattr is set then
		search server for EAs or streams to 
		returns as xattrs */
	rc = CIFSSMBQAllEAs(xid,pTcon,full_path,data,buf_size,
				cifs_sb->local_nls,
				cifs_sb->mnt_cifs_flags & 
					CIFS_MOUNT_MAP_SPECIAL_CHR);

	kfree(full_path);
	FreeXid(xid);
#endif
	return rc;
}

int
cifs_rmdir(struct inode *inode, struct dentry *direntry)
{
	int rc = 0;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct cifsInodeInfo *cifsInode;

	cFYI(1, (" cifs_rmdir, inode = 0x%p with ", inode));

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	down(&inode->i_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&inode->i_sb->s_vfs_rename_sem);
	if(full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}

	rc = CIFSSMBRmDir(xid, pTcon, full_path, cifs_sb->local_nls);

	if (!rc) {
		inode->i_nlink--;
		i_size_write(direntry->d_inode,0);
		direntry->d_inode->i_nlink = 0;
	}

	cifsInode = CIFS_I(direntry->d_inode);
	cifsInode->time = 0;	/* force revalidate to go get info when needed */
	direntry->d_inode->i_ctime = inode->i_ctime = inode->i_mtime =
	    CURRENT_TIME;

	if (full_path)
		kfree(full_path);
	FreeXid(xid);
	return rc;
}

/* gets root inode */
struct inode *cifs_iget(struct super_block *sb, unsigned long ino)
{
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct inode *inode;
	long rc;

	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	cifs_sb = CIFS_SB(inode->i_sb);
	xid = GetXid();

	if (cifs_sb->tcon->unix_ext)
		rc = cifs_get_inode_info_unix(&inode, "", inode->i_sb, xid);
	else
		rc = cifs_get_inode_info(&inode, "", NULL, inode->i_sb, xid,
					 NULL);
	if (rc && cifs_sb->tcon->ipc) {
		cFYI(1, ("ipc connection - fake read inode"));
		inode->i_mode |= S_IFDIR;
		inode->i_nlink = 2;
		inode->i_op = &cifs_ipc_inode_ops;
		inode->i_fop = &simple_dir_operations;
		inode->i_uid = cifs_sb->mnt_uid;
		inode->i_gid = cifs_sb->mnt_gid;
	} else if (rc) {
		_FreeXid(xid);
		iget_failed(inode);
		return ERR_PTR(rc);
	}

	unlock_new_inode(inode);

	/* can not call macro FreeXid here since in a void func
	 * TODO: This is no longer true
	 */
	_FreeXid(xid);
	return inode;
}

int cifs_rmdir(struct inode *inode, struct dentry *direntry)
{
	int rc = 0;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct cifsInodeInfo *cifsInode;

	cFYI(1, ("cifs_rmdir, inode = 0x%p", inode));

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	full_path = build_path_from_dentry(direntry);
	if (full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}

	rc = CIFSSMBRmDir(xid, pTcon, full_path, cifs_sb->local_nls,
			  cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);

	if (!rc) {
		drop_nlink(inode);
		spin_lock(&direntry->d_inode->i_lock);
		i_size_write(direntry->d_inode, 0);
		clear_nlink(direntry->d_inode);
		spin_unlock(&direntry->d_inode->i_lock);
	}

	cifsInode = CIFS_I(direntry->d_inode);
	cifsInode->time = 0;	/* force revalidate to go get info when
				   needed */
	direntry->d_inode->i_ctime = inode->i_ctime = inode->i_mtime =
		current_fs_time(inode->i_sb);

	kfree(full_path);
	FreeXid(xid);
	return rc;
}

int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t device_number) 
{
	int rc = -EPERM;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	struct inode * newinode = NULL;

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

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	down(&direntry->d_sb->s_vfs_rename_sem);
	full_path = build_path_from_dentry(direntry);
	up(&direntry->d_sb->s_vfs_rename_sem);
	if(full_path == NULL)
		rc = -ENOMEM;
	
	if (full_path && (pTcon->ses->capabilities & CAP_UNIX)) {
		rc = CIFSSMBUnixSetPerms(xid, pTcon,
			full_path, mode, current->euid, current->egid,
			device_number, cifs_sb->local_nls);
		if(!rc) {
			rc = cifs_get_inode_info_unix(&newinode, full_path,
						inode->i_sb);
			direntry->d_op = &cifs_dentry_ops;
			if(rc == 0)
				d_instantiate(direntry, newinode);
		}
	}

	if (full_path)
		kfree(full_path);
	FreeXid(xid);

	return rc;
}

static int
cifs_statfs(struct super_block *sb, struct kstatfs *buf)
{
	int xid, rc = -EOPNOTSUPP;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	xid = GetXid();

	cifs_sb = CIFS_SB(sb);
	pTcon = cifs_sb->tcon;

	buf->f_type = CIFS_MAGIC_NUMBER;

	/* instead could get the real value via SMB_QUERY_FS_ATTRIBUTE_INFO */
	buf->f_namelen = PATH_MAX;	/* PATH_MAX may be too long - it would presumably
					   be length of total path, note that some servers may be 
					   able to support more than this, but best to be safe
					   since Win2k and others can not handle very long filenames */
	buf->f_files = 0;	/* undefined */
	buf->f_ffree = 0;	/* unlimited */

#ifdef CONFIG_CIFS_EXPERIMENTAL
/* BB we could add a second check for a QFS Unix capability bit */
    if (pTcon->ses->capabilities & CAP_UNIX)
	    rc = CIFSSMBQFSPosixInfo(xid, pTcon, buf, cifs_sb->local_nls);

    /* Only need to call the old QFSInfo if failed
    on newer one */
    if(rc)
#endif /* CIFS_EXPERIMENTAL */
	rc = CIFSSMBQFSInfo(xid, pTcon, buf, cifs_sb->local_nls);

	/*     
	   int f_type;
	   __fsid_t f_fsid;
	   int f_namelen;  */
	/* BB get from info put in tcon struct at mount time with call to QFSAttrInfo */
	FreeXid(xid);
	return 0;		/* always return success? what if volume is no longer available? */
}

int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
			struct inode *inode, const char *path, int aclflag)
{
	int oplock = 0;
	int xid, rc, access_flags, create_options = 0;
	__u16 fid;
	struct cifs_tcon *tcon;
	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

	if (IS_ERR(tlink))
		return PTR_ERR(tlink);

	tcon = tlink_tcon(tlink);
	xid = GetXid();

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

	if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP)
		access_flags = WRITE_OWNER;
	else
		access_flags = WRITE_DAC;

	rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, access_flags,
			create_options, &fid, &oplock, NULL, cifs_sb->local_nls,
			cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
	if (rc) {
		cERROR(1, "Unable to open file to set ACL");
		goto out;
	}

	rc = CIFSSMBSetCIFSACL(xid, tcon, fid, pnntsd, acllen, aclflag);
	cFYI(DBG2, "SetCIFSACL rc = %d", rc);

	CIFSSMBClose(xid, tcon, fid);
out:
	FreeXid(xid);
	cifs_put_tlink(tlink);
	return rc;
}

static struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
		__u16 fid, u32 *pacllen)
{
	struct cifs_ntsd *pntsd = NULL;
	int xid, rc;
	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);

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

	xid = GetXid();
	rc = CIFSSMBGetCIFSACL(xid, tlink_tcon(tlink), fid, &pntsd, pacllen);
	FreeXid(xid);

	cifs_put_tlink(tlink);

	cFYI(1, "%s: rc = %d ACL len %d", __func__, rc, *pacllen);
	if (rc)
		return ERR_PTR(rc);
	return pntsd;
}

int cifs_xstate_get(struct super_block *sb, struct fs_quota_stat *qstats)
{
	int xid;
	int rc = 0;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifsTconInfo *pTcon;

	if (cifs_sb)
		pTcon = cifs_sb->tcon;
	else
		return -EIO;

	xid = GetXid();
	if (pTcon) {
		cFYI(1, ("pqstats %p", qstats));
	} else
		rc = -EIO;

	FreeXid(xid);
	return rc;
}

int cifs_xstate_set(struct super_block *sb, unsigned int flags, int operation)
{
	int xid;
	int rc = 0;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifsTconInfo *pTcon;

	if (cifs_sb)
		pTcon = cifs_sb->tcon;
	else
		return -EIO;

	xid = GetXid();
	if (pTcon) {
		cFYI(1, ("flags: 0x%x operation: 0x%x", flags, operation));
	} else
		rc = -EIO;

	FreeXid(xid);
	return rc;
}

int cifs_xquota_get(struct super_block *sb, int quota_type, qid_t qid,
		    struct fs_disk_quota *pdquota)
{
	int xid;
	int rc = 0;
	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
	struct cifsTconInfo *pTcon;

	if (cifs_sb)
		pTcon = cifs_sb->tcon;
	else
		return -EIO;

	xid = GetXid();
	if (pTcon) {
		cFYI(1, ("set type: 0x%x id: %d", quota_type, qid));
	} else
		rc = -EIO;

	FreeXid(xid);
	return rc;
}

int
cifs_dir_open(struct inode *inode, struct file *file)
{				/* NB: currently unused since searches are opened in readdir */
	int rc = 0;
	int xid;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;

	xid = GetXid();

	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

	full_path = build_wildcard_path_from_dentry(file->f_dentry);

	cFYI(1, (" inode = 0x%p and full path is %s", inode, full_path));

	if (full_path)
		kfree(full_path);
	FreeXid(xid);
	return rc;
}

int
cifs_readlink(struct dentry *direntry, char __user *pBuffer, int buflen)
{
	struct inode *inode = direntry->d_inode;
	int rc = -EACCES;
	int xid;
	int oplock = FALSE;
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;
	char *full_path = NULL;
	char *tmp_path = NULL;
	char *tmpbuffer;
	unsigned char *referrals = NULL;
	unsigned int num_referrals = 0;
	int len;
	__u16 fid;

	xid = GetXid();
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;

/* BB would it be safe against deadlock to grab this sem
      even though rename itself grabs the sem and calls lookup? */
/*       mutex_lock(&inode->i_sb->s_vfs_rename_mutex);*/
	full_path = build_path_from_dentry(direntry);
/*       mutex_unlock(&inode->i_sb->s_vfs_rename_mutex);*/

	if (full_path == NULL) {
		FreeXid(xid);
		return -ENOMEM;
	}

	cFYI(1,
	     ("Full path: %s inode = 0x%p pBuffer = 0x%p buflen = %d",
	      full_path, inode, pBuffer, buflen));
	if (buflen > PATH_MAX)
		len = PATH_MAX;
	else
		len = buflen;
	tmpbuffer = kmalloc(len, GFP_KERNEL);
	if (tmpbuffer == NULL) {
		kfree(full_path);
		FreeXid(xid);
		return -ENOMEM;
	}

/* BB add read reparse point symlink code and
	Unix extensions symlink code here BB */
/* We could disable this based on pTcon->unix_ext flag instead ... but why? */
	if (cifs_sb->tcon->ses->capabilities & CAP_UNIX)
		rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
				tmpbuffer,
				len - 1,
				cifs_sb->local_nls);
	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
		cERROR(1, ("SFU style symlinks not implemented yet"));
		/* add open and read as in fs/cifs/inode.c */
	} else {
		rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_OPEN, GENERIC_READ,
				OPEN_REPARSE_POINT, &fid, &oplock, NULL,
				cifs_sb->local_nls,
				cifs_sb->mnt_cifs_flags &
					CIFS_MOUNT_MAP_SPECIAL_CHR);
		if (!rc) {
			rc = CIFSSMBQueryReparseLinkInfo(xid, pTcon, full_path,
				tmpbuffer,
				len - 1,
				fid,
				cifs_sb->local_nls);
			if (CIFSSMBClose(xid, pTcon, fid)) {
				cFYI(1, ("Error closing junction point "
					 "(open for ioctl)"));
			}
			if (rc == -EIO) {
				/* Query if DFS Junction */
				tmp_path =
					kmalloc(MAX_TREE_SIZE + MAX_PATHCONF + 1,
						GFP_KERNEL);
				if (tmp_path) {
					strncpy(tmp_path, pTcon->treeName,
						MAX_TREE_SIZE);
					strncat(tmp_path, full_path,
						MAX_PATHCONF);
					rc = get_dfs_path(xid, pTcon->ses,
						tmp_path,
						cifs_sb->local_nls,
						&num_referrals, &referrals,
						cifs_sb->mnt_cifs_flags &
						    CIFS_MOUNT_MAP_SPECIAL_CHR);
					cFYI(1, ("Get DFS for %s rc = %d ",
						tmp_path, rc));
					if ((num_referrals == 0) && (rc == 0))
						rc = -EACCES;
					else {
						cFYI(1, ("num referral: %d",
							num_referrals));
						if (referrals) {
							cFYI(1,("referral string: %s", referrals));
							strncpy(tmpbuffer,
								referrals,
//.........这里部分代码省略.........

void *
cifs_follow_link(struct dentry *direntry, struct nameidata *nd)
{
	struct inode *inode = direntry->d_inode;
	int rc = -EACCES;
	int xid;
	char *full_path = NULL;
	char *target_path = ERR_PTR(-ENOMEM);
	struct cifs_sb_info *cifs_sb;
	struct cifsTconInfo *pTcon;

	xid = GetXid();

	full_path = build_path_from_dentry(direntry);

	if (!full_path)
		goto out_no_free;

	cFYI(1, ("Full path: %s inode = 0x%p", full_path, inode));
	cifs_sb = CIFS_SB(inode->i_sb);
	pTcon = cifs_sb->tcon;
	target_path = kmalloc(PATH_MAX, GFP_KERNEL);
	if (!target_path) {
		target_path = ERR_PTR(-ENOMEM);
		goto out;
	}

	/* We could change this to:
		if (pTcon->unix_ext)
	   but there does not seem any point in refusing to
	   get symlink info if we can, even if unix extensions
	   turned off for this mount */

	if (pTcon->ses->capabilities & CAP_UNIX)
		rc = CIFSSMBUnixQuerySymLink(xid, pTcon, full_path,
					     target_path,
					     PATH_MAX-1,
					     cifs_sb->local_nls);
	else {
		/* BB add read reparse point symlink code here */
		/* rc = CIFSSMBQueryReparseLinkInfo */
		/* BB Add code to Query ReparsePoint info */
		/* BB Add MAC style xsymlink check here if enabled */
	}

	if (rc == 0) {

/* BB Add special case check for Samba DFS symlinks */

		target_path[PATH_MAX-1] = 0;
	} else {
		kfree(target_path);
		target_path = ERR_PTR(rc);
	}

out:
	kfree(full_path);
out_no_free:
	FreeXid(xid);
	nd_set_link(nd, target_path);
	return NULL;	/* No cookie */
}