Name

NFSPROC3_MKNOD - Create a Special Device

Call Arguments

 

struct devicedata3 {
    sattr3 dev_attributes;
    specdata3 spec;
};

union mknoddata3 switch (ftype3 type) {
    case NF3CHR:
    case NF3BLK:
        devicedata3 device;
    case NF3SOCK:
    case NF3FIFO:
        sattr3 pipe_attributes;
    default:
        void;
};

struct MKNOD3args {
    diropargs3 where;
    mknoddata3 what;
};

Return Arguments

 

struct MKNOD3resok {
    post_op_fh3 obj;
    post_op_attr obj_attributes;
    wcc_data dir_wcc;
};

struct MKNOD3resfail {
    wcc_data dir_wcc;
};

union MKNOD3res switch (nfsstat3 status) {
    case NFS3_OK:
        MKNOD3resok resok;
    default:
        MKNOD3resfail resfail;
};

RPC Procedure Description

 

MKNOD3res
NFSPROC3_MKNOD(MKNOD3args) = 11;

Description

Procedure MKNOD creates a new special file of the type what.type. Special files can be device files or named pipes.

On entry, the arguments in MKNOD3args are:

where

The location of the special file to be created:

dir

The file handle for the directory in which the special file is to be created.

name

The name that is to be associated with the created special file. See General File Name Requirements for more information on file names.

what

A discriminated union identifying the type of the special file to be created along with the data and attributes appropriate to the type of the special file:

type

The type of the object to be created.

When creating a character special file (.IR what.type is NF3CHR) or a block special file (.IR what.type is NF3BLK), what includes:

device

A devicedata3 structure with the following components:

dev_attributes

The initial attributes for the special file.

spec

The major number stored in device.spec.specdata1 and the minor number stored in device.spec.specdata2.

When creating a socket (.IR what.type is NF3SOCK) or a FIFO (.IR what.type is NF3FIFO), what includes:

pipe_attributes

The initial attributes for the special file.

Upon successful return, MKNOD3res.status is NFS3_OK and MKNOD3res.resok contains:

obj

The file handle for the newly created special file.

obj_attributes

The attributes for the newly created special file.

dir_wcc

Weak cache consistency data for the directory where.dir. For a client that requires only the post-.IR MKNOD directory attributes, these can be found in dir_wcc.after.

Otherwise, MKNOD3res.status contains the error on failure and MKNOD3res.resfail contains the following:

dir_wcc

Weak cache consistency data for the directory where.dir. For a client that requires only the post-.IR MKNOD directory attributes, these can be found in dir_wcc.after. Even though the MKNOD failed, full wcc_data is returned to allow the client to determine whether the failing MKNOD changed the directory.

Implementation Guidance

See General File Name Requirements for more information on file names.

Without explicit support for special file type creation in the NFS Version 2 protocol, fields in the CREATE arguments were overloaded to indicate creation of certain types of objects. This overloading is not necessary in the NFS Version 3 protocol.

If the server does not support any of the defined types, the NFS3ERR_NOTSUPP error should be returned. Otherwise, if the server does not support the target type or the target type is invalid, the NFS3ERR_BADTYPE error should be returned. Note that NF3REG, NF3DIR and NF3LNK are invalid types for MKNOD. The procedures, CREATE, MKDIR and SYMLINK should be used to create these file types, respectively, instead of MKNOD.

Return Codes

NFS3ERR_IO

I/O error. Some sort of hard error occurred when the operation was in progress. This could be a disk error, for example.

NFS3ERR_ACCES

Permission denied. The caller does not have the correct permission to perform the requested operation. Contrast this with NFS3ERR_PERM, which restricts itself to owner permission failures.

NFS3ERR_EXIST

File exists. The file specified already exists.

NFS3ERR_NOTDIR

Not a directory. The caller specified a non-directory in a directory operation.

NFS3ERR_NOSPC

No space left on device. The operation would have caused the server's file system to exceed its limit.

NFS3ERR_ROFS

Read-only file system. A modifying operation was attempted on a read-only file system.

NFS3ERR_NAMETOOLONG

The filename in an operation was too long.

NFS3ERR_DQUOT

Resource (quota) hard limit exceeded. The user's resource limit on the server has been exceeded.

NFS3ERR_STALE

Invalid file handle. The file handle given in the arguments was invalid. The file referred to by that file handle no longer exists or access to it has been revoked.

NFS3ERR_BADHANDLE

Invalid NFS file handle. The file handle failed internal consistency checks.

NFS3ERR_NOTSUPP

The operation is not supported.

NFS3ERR_SERVERFAULT

An error occurred on the server, which does not map to any of the valid NFS Version 3 protocol error values. The client should translate this into an appropriate error. Clients based on an XPG system may choose to translate this to EIO.

NFS3ERR_BADTYPE

An attempt was made to create an object of a type not supported by the server.