VOP_ALLOCATE (9)

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Copyright (c) 2013 Hudson River Trading LLC
Written by: John H. Baldwin <jhb@FreeBSD.org>
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(The comments found at the beginning of the groff file "man9/VOP_ALLOCATE.9freebsd".)

NAME

VOP_ALLOCATE - allocate storage for a file

SYNOPSIS

In sys/param.h In sys/vnode.h Ft int Fn VOP_ALLOCATE struct vnode *vp off_t *offset off_t *len

DESCRIPTION

This call allocates storage for a range of offsets in a file. It is used to implement the posix_fallocate system call.

Its arguments are:

Fa vp

The vnode of the file.

Fa offset

The start of the range to allocate storage for in the file.

Fa len

The length of the range to allocate storage for in the file.

The Fa offset and Fa len arguments are updated to reflect the portion of the range that still needs to be allocated on return. A partial allocation is considered a successful operation. The file's contents are not changed.

LOCKS

The file should be exclusively locked on entry and will still be locked on exit.

RETURN VALUES

Zero is returned if the call is successful, otherwise an appropriate error code is returned.

ERRORS

Bq Er EFBIG

An attempt was made to write a file that exceeds the process's file size limit or the maximum file size.

Bq Er ENOSPC

The file system is full.

Bq Er EPERM

An append-only flag is set on the file, but the caller is attempting to write before the current end of file.

SEE ALSO

vnode(9), VOP_READ9, VOP_WRITE9