switch from `data_model::DataInit` to `zerocopy`
No behavior change intended.
The `DataInit` trait has been deleted in favor of the `zerocopy` crate,
which doesn't require any unsafe code to use.
Bug: 269356487
Test: m
Change-Id: Ie1ee815ca1beb06b336cb060a651b75c3b02e1c0
diff --git a/libs/devicemapper/Android.bp b/libs/devicemapper/Android.bp
index 8f9c25c..5332469 100644
--- a/libs/devicemapper/Android.bp
+++ b/libs/devicemapper/Android.bp
@@ -13,10 +13,10 @@
"libanyhow",
"libbitflags",
"liblibc",
- "libdata_model",
"libhex",
"libnix",
"libuuid",
+ "libzerocopy",
],
multilib: {
lib32: {
diff --git a/libs/devicemapper/src/crypt.rs b/libs/devicemapper/src/crypt.rs
index 8281b34..36c45c7 100644
--- a/libs/devicemapper/src/crypt.rs
+++ b/libs/devicemapper/src/crypt.rs
@@ -20,10 +20,10 @@
use crate::DmTargetSpec;
use anyhow::{ensure, Context, Result};
-use data_model::DataInit;
use std::io::Write;
use std::mem::size_of;
use std::path::Path;
+use zerocopy::AsBytes;
const SECTOR_SIZE: u64 = 512;
@@ -174,7 +174,7 @@
header.next = aligned_size as u32;
let mut buf = Vec::with_capacity(aligned_size);
- buf.write_all(header.as_slice())?;
+ buf.write_all(header.as_bytes())?;
buf.write_all(body.as_bytes())?;
buf.write_all(vec![0; padding].as_slice())?;
diff --git a/libs/devicemapper/src/lib.rs b/libs/devicemapper/src/lib.rs
index 868ac5a..8d004f9 100644
--- a/libs/devicemapper/src/lib.rs
+++ b/libs/devicemapper/src/lib.rs
@@ -32,12 +32,13 @@
#![cfg_attr(test, allow(unused))]
use anyhow::{Context, Result};
-use data_model::DataInit;
use std::fs::{File, OpenOptions};
use std::io::Write;
use std::mem::size_of;
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
+use zerocopy::AsBytes;
+use zerocopy::FromZeroes;
/// Exposes DmCryptTarget & related builder
pub mod crypt;
@@ -87,7 +88,7 @@
// `DmTargetSpec` is the header of the data structure for a device-mapper target. When doing the
// ioctl, one of more `DmTargetSpec` (and its body) are appened to the `DmIoctl` struct.
#[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, AsBytes, FromZeroes)]
struct DmTargetSpec {
sector_start: u64,
length: u64, // number of 512 sectors
@@ -96,13 +97,9 @@
target_type: [u8; DM_MAX_TYPE_NAME],
}
-// SAFETY: C struct is safe to be initialized from raw data
-unsafe impl DataInit for DmTargetSpec {}
-
impl DmTargetSpec {
fn new(target_type: &str) -> Result<Self> {
- // safe because the size of the array is the same as the size of the struct
- let mut spec: Self = *DataInit::from_mut_slice(&mut [0; size_of::<Self>()]).unwrap();
+ let mut spec = Self::new_zeroed();
spec.target_type.as_mut().write_all(target_type.as_bytes())?;
Ok(spec)
}
@@ -110,8 +107,7 @@
impl DmIoctl {
fn new(name: &str) -> Result<DmIoctl> {
- // safe because the size of the array is the same as the size of the struct
- let mut data: Self = *DataInit::from_mut_slice(&mut [0; size_of::<Self>()]).unwrap();
+ let mut data: Self = Self::new_zeroed();
data.version[0] = DM_VERSION_MAJOR;
data.version[1] = DM_VERSION_MINOR;
data.version[2] = DM_VERSION_PATCHLEVEL;
@@ -202,7 +198,7 @@
}
let mut payload = Vec::with_capacity(payload_size);
- payload.extend_from_slice(data.as_slice());
+ payload.extend_from_slice(data.as_bytes());
payload.extend_from_slice(target);
dm_table_load(self, payload.as_mut_ptr() as *mut DmIoctl)
.context("failed to load table")?;
diff --git a/libs/devicemapper/src/loopdevice.rs b/libs/devicemapper/src/loopdevice.rs
index 16b5b65..9dc722b 100644
--- a/libs/devicemapper/src/loopdevice.rs
+++ b/libs/devicemapper/src/loopdevice.rs
@@ -25,15 +25,14 @@
use crate::util::*;
use anyhow::{Context, Result};
-use data_model::DataInit;
use libc::O_DIRECT;
use std::fs::{File, OpenOptions};
-use std::mem::size_of;
use std::os::unix::fs::OpenOptionsExt;
use std::os::unix::io::AsRawFd;
use std::path::{Path, PathBuf};
use std::thread;
use std::time::{Duration, Instant};
+use zerocopy::FromZeroes;
use crate::loopdevice::sys::*;
@@ -122,9 +121,7 @@
.custom_flags(if direct_io { O_DIRECT } else { 0 })
.open(&path)
.context(format!("failed to open {:?}", path.as_ref()))?;
- // safe because the size of the array is the same as the size of the struct
- let mut config: loop_config =
- *DataInit::from_mut_slice(&mut [0; size_of::<loop_config>()]).unwrap();
+ let mut config = loop_config::new_zeroed();
config.fd = backing_file.as_raw_fd() as u32;
config.block_size = 4096;
config.info.lo_offset = offset;
diff --git a/libs/devicemapper/src/loopdevice/sys.rs b/libs/devicemapper/src/loopdevice/sys.rs
index a35eaa9..ce4ef61 100644
--- a/libs/devicemapper/src/loopdevice/sys.rs
+++ b/libs/devicemapper/src/loopdevice/sys.rs
@@ -15,7 +15,7 @@
*/
use bitflags::bitflags;
-use data_model::DataInit;
+use zerocopy::FromZeroes;
// This UAPI is copied and converted from include/uapi/linux/loop.h Note that this module doesn't
// implement all the features introduced in loop(4). Only the features that are required to support
@@ -28,7 +28,7 @@
pub const LOOP_CLR_FD: libc::c_ulong = 0x4C01;
#[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, FromZeroes)]
pub struct loop_config {
pub fd: u32,
pub block_size: u32,
@@ -36,11 +36,8 @@
pub reserved: [u64; 8],
}
-// SAFETY: C struct is safe to be initialized from raw data
-unsafe impl DataInit for loop_config {}
-
#[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, FromZeroes)]
pub struct loop_info64 {
pub lo_device: u64,
pub lo_inode: u64,
@@ -57,13 +54,12 @@
pub lo_init: [u64; 2],
}
-// SAFETY: C struct is safe to be initialized from raw data
-unsafe impl DataInit for loop_info64 {}
+#[repr(transparent)]
+#[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, FromZeroes)]
+pub struct Flag(u32);
bitflags! {
- #[repr(transparent)]
- #[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
- pub struct Flag: u32 {
+ impl Flag: u32 {
const LO_FLAGS_READ_ONLY = 1 << 0;
const LO_FLAGS_AUTOCLEAR = 1 << 2;
const LO_FLAGS_PARTSCAN = 1 << 3;
diff --git a/libs/devicemapper/src/sys.rs b/libs/devicemapper/src/sys.rs
index 3cecde3..bd1e165 100644
--- a/libs/devicemapper/src/sys.rs
+++ b/libs/devicemapper/src/sys.rs
@@ -15,7 +15,8 @@
*/
use bitflags::bitflags;
-use data_model::DataInit;
+use zerocopy::AsBytes;
+use zerocopy::FromZeroes;
// UAPI for device mapper can be found at include/uapi/linux/dm-ioctl.h
@@ -44,7 +45,7 @@
}
#[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, AsBytes, FromZeroes)]
pub struct DmIoctl {
pub version: [u32; 3],
pub data_size: u32,
@@ -60,9 +61,6 @@
pub data: [u8; 7],
}
-// SAFETY: C struct is safe to be initialized from raw data
-unsafe impl DataInit for DmIoctl {}
-
pub const DM_VERSION_MAJOR: u32 = 4;
pub const DM_VERSION_MINOR: u32 = 0;
pub const DM_VERSION_PATCHLEVEL: u32 = 0;
@@ -71,10 +69,12 @@
pub const DM_UUID_LEN: usize = 129;
pub const DM_MAX_TYPE_NAME: usize = 16;
+#[repr(transparent)]
+#[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd, AsBytes, FromZeroes)]
+pub struct Flag(u32);
+
bitflags! {
- #[repr(transparent)]
- #[derive(Copy, Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
- pub struct Flag: u32 {
+ impl Flag: u32 {
const DM_READONLY_FLAG = 1 << 0;
const DM_SUSPEND_FLAG = 1 << 1;
const DM_PERSISTENT_DEV_FLAG = 1 << 3;
diff --git a/libs/devicemapper/src/verity.rs b/libs/devicemapper/src/verity.rs
index e0c5e52..24584f8 100644
--- a/libs/devicemapper/src/verity.rs
+++ b/libs/devicemapper/src/verity.rs
@@ -19,10 +19,10 @@
// which is then given to `DeviceMapper` to create a mapper device.
use anyhow::{bail, Context, Result};
-use data_model::DataInit;
use std::io::Write;
use std::mem::size_of;
use std::path::Path;
+use zerocopy::AsBytes;
use crate::util::*;
use crate::DmTargetSpec;
@@ -195,7 +195,7 @@
header.next = aligned_size as u32;
let mut buf = Vec::with_capacity(aligned_size);
- buf.write_all(header.as_slice())?;
+ buf.write_all(header.as_bytes())?;
buf.write_all(body.as_bytes())?;
buf.write_all(vec![0; padding].as_slice())?;
Ok(DmVerityTarget(buf.into_boxed_slice()))