docs/reference/syscalls/vmo_set_size.md

# zx_vmo_set_size

## NAME

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Resize a VMO object.

## SYNOPSIS

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```c
#include <zircon/syscalls.h>

zx_status_t zx_vmo_set_size(zx_handle_t handle, uint64_t size);
```

## DESCRIPTION

`zx_vmo_set_size()` sets the new size of a VMO object.

The size will be rounded up to the next page size boundary.
Subsequent calls to [`zx_vmo_get_size()`] will return the rounded up size.

The content size of the VMO will be set to the given (unrounded) size.
Use [`zx_object_get_property()`] with **ZX_PROP_VMO_CONTENT_SIZE** to read the
content size of the VMO. Use [`zx_object_set_property()`] with
**ZX_PROP_VMO_CONTENT_SIZE** to set the content size of the VMO without
actually resizing the VMO.

The data in the VMO between the given size and the end of the VMO (i.e., the next page boundary)
will be overritten with zeros.

## RIGHTS

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*handle* must be of type **ZX_OBJ_TYPE_VMO** and have **ZX_RIGHT_WRITE**.

## RETURN VALUE

`zx_vmo_set_size()` returns **ZX_OK** on success. In the event
of failure, a negative error value is returned.

## ERRORS

**ZX_ERR_BAD_HANDLE**  *handle* is not a valid handle.

**ZX_ERR_WRONG_TYPE**  *handle* is not a VMO handle.

**ZX_ERR_ACCESS_DENIED**  *handle* does not have the **ZX_RIGHT_WRITE** right.

**ZX_ERR_UNAVAILABLE** The VMO was not created with **ZX_VMO_RESIZABLE**
or **ZX_VMO_CHILD_RESIZABLE**.

**ZX_ERR_OUT_OF_RANGE**  Requested size is too large.

**ZX_ERR_NO_MEMORY**  Failure due to lack of system memory.

**ZX_ERR_BAD_STATE**  Requested size would discard pinned pages.

## SEE ALSO

 - [`zx_vmo_create()`]
 - [`zx_vmo_create_child()`]
 - [`zx_vmo_get_size()`]
 - [`zx_vmo_op_range()`]
 - [`zx_vmo_read()`]
 - [`zx_vmo_write()`]

<!-- References updated by update-docs-from-fidl, do not edit. -->

[`zx_object_get_property()`]: object_get_property.md
[`zx_object_set_property()`]: object_set_property.md
[`zx_vmo_create()`]: vmo_create.md
[`zx_vmo_create_child()`]: vmo_create_child.md
[`zx_vmo_get_size()`]: vmo_get_size.md
[`zx_vmo_op_range()`]: vmo_op_range.md
[`zx_vmo_read()`]: vmo_read.md
[`zx_vmo_write()`]: vmo_write.md