man VOP_SETEXTATTR (9): set named extended attribute for a vnode

SYNOPSIS

In sys/param.h In sys/vnode.h In sys/extattr.h Ft int Fn VOP_SETEXTATTR struct vnode *vp int attrnamespace const char *name struct uio *uio struct ucred *cred struct thread *td

DESCRIPTION

This vnode call may be used to set specific named extended attribute for a file or directory.

Its arguments are:

Fa vp: The vnode of the file or directory.
Fa attrnamespace: Integer constant indicating which extended attribute namespace the attribute name is present in.
Fa name: Pointer to a null-terminated character string containing the attribute name.
Fa uio: The location of the data to be read or written.
Fa cred: The user credentials to use in authorizing the request.
Fa td: The thread setting the extended attribute.

The uio structure is used in a manner similar to the argument of the same name in VOP_WRITE9. However, as extended attributes provide a strict "name=value" semantic, non-zero offsets will be rejected.

The Fa uio pointer may be NULL to indicate that the specified extended attribute should be deleted.

The Fa cred pointer may be NULL to indicate that access control checks are not to be performed, if possible. This Fa cred setting might be used to allow the kernel to authorize extended attribute changes that the active process might not be permitted to make.

Extended attribute semantics may vary by file system implementing the call. More information on extended attributes may be found in extattr(9).

LOCKS

The vnode will be locked on entry and should remain locked on return.

RETURN VALUES

If the extended attribute is successfully set, then zero is returned. Otherwise, an appropriate error code is returned.

ERRORS

Bq Er EACCES: The caller does not have the appropriate privilege.
Bq Er ENXIO: The request was not valid in this file system for the specified vnode and attribute name.
Bq Er ENOMEM: Insufficient memory available to fulfill the request.
Bq Er EFAULT: The uio structure refers to an invalid userspace address.
Bq Er EINVAL: The name, namespace, or uio argument is invalid.
Bq Er EOPNOTSUPP: The file system does not support Fn VOP_SETEXTATTR .
Bq Er ENOSPC: The file system is out of space.
Bq Er EROFS: The file system is read-only.

AUTHORS

This manual page was written by An Robert Watson .