v_create (BPX1VCR, BPX4VCR)

Function

The v_create service creates a new file in the directory that is represented by Directory_vnode_token. The file can be a regular, FIFO, or character special file. The input Attr is used to define the attributes of the new file. A token that represents the new file is returned in File_vnode_token.

Requirements

Operation	Environment
Authorization:	Supervisor state or problem state, any PSW key
Dispatchable unit mode:	Task
Cross memory mode:	PASN = HASN
AMODE (BPX1VCR):	31-bit
AMODE (BPX4VCR):	64-bit
ASC mode:	Primary mode
Interrupt status:	Enabled for interrupts
Locks:	Unlocked
Control parameters:	All parameters must be addressable by the caller and in the primary address space.

Format

CALL BPX1VCR,(Directory_vnode_token,
              OSS,
              Name_length,
              Name,
              Attr_length,
              Attr,
              File_vnode_token,
              Return_value,
              Return_code,
              Reason_code)

AMODE 64 callers use BPX4VCR with the same parameters.

Parameters

Directory_vnode_token

Supplied parameter

Type:: Token
Length:: 8 bytes

The name of an 8-byte area that contains a vnode token that represents the directory in which the v_create service creates the new file that is named in the Name parameter.

OSS

Supplied and returned parameter

Type:: Structure
Length:: OSS#LENGTH (from the BPXYOSS macro)

The name of an area that contains operating-system-specific parameters. This area is mapped by the BPXYOSS macro (see BPXYOSS — Map operating system specific information).

Name_length

Supplied parameter

Type:: Integer
Length:: Fullword

The name of a fullword that contains the length of the filename that is to be created. The name can be up to 255 bytes long.

Name

Supplied parameter

Type:: Character string
Length:: Specified by Name_length parameter

The name of an area, of length Name_length, that contains the filename that is to be created. It must not contain null characters (X'00').

Attr_length

Supplied parameter

Type:: Integer
Length:: Fullword

The name of a fullword that contains the length of the area that is passed in the Attr parameter. To determine the value of Attr_length, use the ATTR structure (see BPXYATTR — Map file attributes for v_ system calls).

Attr

Supplied and returned parameter

Type:: Structure
Length:: Specified by the Attr_length parameter

The name of an area, of length Attr_length, that is to be used by the v_create service to set the attributes of the file that is to be created. The attributes of the file that is created are also returned in this area. This area is mapped by the ATTR structure (see BPXYATTR — Map file attributes for v_ system calls).

File_vnode_token

Returned parameter

Type:: Token
Length:: 8 bytes

The name of an 8-byte area in which the v_create service returns a Vnode_token of the file created.

Return_value

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword where the v_create service returns 0 if the request is successful, or -1 if it is not successful.

Return_code

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the v_create service stores the return code. The v_create service returns Return_code only if Return_value is -1. See z/OS UNIX System Services Messages and Codes for a complete list of possible return code values. The v_create service can return one of the following values in the Return_code parameter:

Return_code	Explanation
EACCES	The calling process does not have permission to write in the directory that was specified.
EEXIST	The named file exists.
EFBIG	The file size limit for the process is set to zero, which means files cannot be created.
EINVAL	Parameter error; for example, a supplied area was too small. The following reason codes can accompany the return code: JRSmallAttr, JRInvalidAttr, JrNoName, JrNullInPath, JRVTokenFreed, JRWrongPID, JRStaleVnodeTok, JRInvalidVnodeTok, JRInvalidOSS.
EMFILE	The maximum number of vnode tokens have been created.
ENAMETOOLONG	The name is longer than 255 characters.
ENFILE	An error occurred while storage was being obtained for a vnode token.
ENOTDIR	The supplied token did not represent a directory.
EPERM	The operation is not permitted. The caller of the service is not registered as a server.
EROFS	The Directory_vnode_token is a file on a read-only file system.

Reason_code

Returned parameter

Type:: Integer
Length:: Fullword

The name of a fullword in which the v_create service stores the reason code. The v_create service returns a Reason_code only if Return_value is -1. Reason_code further qualifies the Return_code value. See z/OS UNIX System Services Messages and Codes for the reason codes.

Usage notes

The following ATTR fields are provided by the caller:
Attr.at_hdr.cbid

Contains Attr#ID (from the ATTR structure).

AttrLen

Specifies the length of the ATTR structure.

AttrMode

Specifies the file mode permission bits. See Mapping macros in z/OS UNIX System Services Programming: Assembler Callable Services Referencefor the mapping of this field.

AttrType

Specifies the file type: regular, FIFO, or character special. See Mapping macros in z/OS UNIX System Services Programming: Assembler Callable Services Referencefor the mapping of this field.

AttrMajorNumber

Specifies the major number for character special files.

AttrMinorNumber

Specifies the minor number for character special files.

AttrCVerSet

Indicates whether the Creation Verifier (AttrCVer) is present.

AttrCVer

Specifies the Creation Verifier for the file. When the AttrCVerSet bit is on and the create is successful, the PFS saves the Creation Verifier, and the server can retrieve it with v_lookup. The Creation Verifier allows the server to determine whether a v_create that returns EEXIST should be considered successful or not. If AttrCVerSet is on, AttrCVer is returned, and the server can compare the file's Creation Verifier with the input Creation Verifier on the v_create. If they are the same, it considers the v_create successful; that is, it is a duplicate of an earlier successful request.

Other fields in the ATTR area should be set to zeros.
If the file that is named in the Name parameter exists, the v_create service returns a failing return code, and no File_vnode_token is returned.
Vnode tokens that are returned by the v_create service are not inherited across a fork callable service.
The caller is responsible for freeing vnode tokens that are returned by the v_create service by calling to the v_rel service when they are no longer needed.
If the file size limit for the process is set to zero, files cannot be created and file creation fails with EFBIG.
The value set by umask() for the process does not affect the setting of the mode permission bits.

Related services

Characteristics and restrictions

A process must be registered as a server before the v_create service is permitted; see v_reg (BPX1VRG, BPX4VRG) — Register a process as a server.

Examples

For an example using this callable service, see BPX1VCR, BPX4VCR (v_create).