recovery_util_block/
lib.rs

1// Copyright 2022 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5use anyhow::{anyhow, Context as _, Error};
6use fidl_fuchsia_device::ControllerMarker;
7use fidl_fuchsia_hardware_block::BlockMarker;
8
9#[derive(Debug, PartialEq, Clone)]
10pub struct BlockDevice {
11    /// Topological path of the block device.
12    pub topo_path: String,
13    /// Path to the block device under /dev/class/block.
14    pub class_path: String,
15    /// Size of the block device, in bytes.
16    pub size: u64,
17}
18
19impl BlockDevice {
20    /// Returns true if this block device is a disk.
21    pub fn is_disk(&self) -> bool {
22        // partitions have paths like this:
23        // /dev/sys/platform/pci/00:14.0/xhci/usb-bus/001/001/ifc-000/ums/lun-000/block/part-000/block
24        // while disks are like this:
25        // /dev/sys/platform/pci/00:17.0/ahci/sata2/block
26        !self.topo_path.contains("/block/part-")
27    }
28}
29
30pub async fn get_block_device(class_path: &str) -> Result<Option<BlockDevice>, Error> {
31    let controller = fuchsia_component::client::connect_to_protocol_at_path::<ControllerMarker>(
32        format!("{class_path}/device_controller").as_str(),
33    )?;
34    let topo_path = controller
35        .get_topological_path()
36        .await
37        .context("FIDL: get_topological_path()")?
38        .map_err(zx::Status::from_raw)
39        .context("response: get_topological_path()")?;
40    if topo_path.contains("/ramdisk-") {
41        // This is probably ram, skip it
42        Ok(None)
43    } else {
44        let block =
45            fuchsia_component::client::connect_to_protocol_at_path::<BlockMarker>(class_path)?;
46        let info = block
47            .get_info()
48            .await
49            .context("FIDL: get_info()")?
50            .map_err(zx::Status::from_raw)
51            .context("response: get_info()")?;
52        let block_count = info.block_count;
53        let block_size = info.block_size;
54        let size = block_count.checked_mul(block_size.into()).ok_or_else(|| {
55            anyhow!("device size overflow: block_count={} block_size={}", block_count, block_size)
56        })?;
57        let class_path = class_path.to_owned();
58        Ok(Some(BlockDevice { topo_path, class_path, size }))
59    }
60}
61
62pub async fn get_block_devices() -> Result<Vec<BlockDevice>, Error> {
63    const BLOCK_DIR: &str = "/dev/class/block";
64    let entries = std::fs::read_dir(BLOCK_DIR)?;
65    let futures = entries.map(|entry| async {
66        let entry = entry?;
67        let path = entry.path();
68        let class_path =
69            path.to_str().ok_or_else(|| anyhow!("path contains non-UTF8: {}", path.display()))?;
70        get_block_device(class_path).await
71    });
72    let options = futures::future::try_join_all(futures).await?;
73    let devices = options.into_iter().filter_map(std::convert::identity).collect();
74    Ok(devices)
75}
recovery_util_block/lib.rs

recovery_util_block/
lib.rs
