Provided by: freebsd-manpages_6.2-1_all
VOP_CREATEVOBJECT, VOP_DESTROYVOBJECT, VOP_GETVOBJECT - VM object
VOP_CREATEVOBJECT(struct vnode *vp, struct ucred *cred,
struct thread *td);
VOP_DESTROYVOBJECT(struct vnode *vp);
VOP_GETVOBJECT(struct vnode *vp, struct vm_object **objpp);
These calls are used to control the association of a VM object with a
The arguments specific to these functions are:
vp The vnode of the file.
objpp The VM object being returned, or NULL if the caller wants to test
for the existence of the VM object).
VFS(9) invokes VOP_CREATEVOBJECT() when it needs to create a VM object
for the given vnode(9). File system code may pass this call down to the
underlying file system. This VOP can be called multiple times, and file
system code should ignore any additional calls, exiting with a zero
VOP_DESTROYVOBJECT() is called when a vnode(9) is recycled.
VOP_GETVOBJECT() should be used by all kernel code to get a VM object.
The returned VM object may belong to a different file system in the case
of stacked mounts.
VFS(9) has three functions which perform standard operations by creating
and destroying VM objects. These functions are: vop_stdcreatevobject(),
vop_stddestroyvobject() and vop_stdgetvobject().
Note: a vnode(9) should be locked on entry and must be left locked on
The VOP_CREATEVOBJECT(), VOP_DESTROYVOBJECT() and VOP_GETVOBJECT()
functions return zero on success, or a non-zero value on failure. Zero
is returned on success, otherwise an error is returned.
By default, file systems leave VM object handling to the vop_std*()
vnode(9), VOP_GETPAGES(9), VOP_PUTPAGES(9)
This manual page was written by Boris Popov.