diff options
Diffstat (limited to 'rust-src/src/filesystem.rs')
| -rw-r--r-- | rust-src/src/filesystem.rs | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/rust-src/src/filesystem.rs b/rust-src/src/filesystem.rs new file mode 100644 index 00000000..28a2ab9e --- /dev/null +++ b/rust-src/src/filesystem.rs @@ -0,0 +1,217 @@ +extern "C" { + pub static stdout: *mut libc::FILE; +} +use bch_bindgen::{debug, info}; +use colored::Colorize; +use getset::{CopyGetters, Getters}; +use std::path::PathBuf; +#[derive(Getters, CopyGetters)] +pub struct FileSystem { + /// External UUID of the bcachefs + #[getset(get = "pub")] + uuid: uuid::Uuid, + /// Whether filesystem is encrypted + #[getset(get_copy = "pub")] + encrypted: bool, + /// Super block + #[getset(get = "pub")] + sb: bcachefs::bch_sb_handle, + /// Member devices for this filesystem + #[getset(get = "pub")] + devices: Vec<PathBuf>, +} +impl std::fmt::Debug for FileSystem { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_struct("FileSystem") + .field("uuid", &self.uuid) + .field("encrypted", &self.encrypted) + .field("devices", &self.device_string()) + .finish() + } +} +use std::fmt; +impl std::fmt::Display for FileSystem { + fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { + let devs = self.device_string(); + write!( + f, + "{:?}: locked?={lock} ({}) ", + self.uuid, + devs, + lock = self.encrypted + ) + } +} + +impl FileSystem { + pub(crate) fn new(sb: bcachefs::bch_sb_handle) -> Self { + Self { + uuid: sb.sb().uuid(), + encrypted: sb.sb().crypt().is_some(), + sb: sb, + devices: Vec::new(), + } + } + + pub fn device_string(&self) -> String { + use itertools::Itertools; + self.devices.iter().map(|d| d.display()).join(":") + } + + pub fn mount( + &self, + target: impl AsRef<std::path::Path>, + options: impl AsRef<str>, + ) -> anyhow::Result<()> { + let src = self.device_string(); + let (data, mountflags) = parse_mount_options(options); + + info!( + "mounting bcachefs filesystem, {}", + target.as_ref().display() + ); + mount_inner(src, target, "bcachefs", mountflags, data) + } +} + +fn mount_inner( + src: String, + target: impl AsRef<std::path::Path>, + fstype: &str, + mountflags: u64, + data: Option<String>, +) -> anyhow::Result<()> { + use std::{ + ffi::{c_void, CString}, + os::{raw::c_char, unix::ffi::OsStrExt}, + }; + + // bind the CStrings to keep them alive + let src = CString::new(src)?; + let target = CString::new(target.as_ref().as_os_str().as_bytes())?; + let data = data.map(CString::new).transpose()?; + let fstype = CString::new(fstype)?; + + // convert to pointers for ffi + let src = src.as_c_str().to_bytes_with_nul().as_ptr() as *const c_char; + let target = target.as_c_str().to_bytes_with_nul().as_ptr() as *const c_char; + let data = data.as_ref().map_or(std::ptr::null(), |data| { + data.as_c_str().to_bytes_with_nul().as_ptr() as *const c_void + }); + let fstype = fstype.as_c_str().to_bytes_with_nul().as_ptr() as *const c_char; + + let ret = { + info!("mounting filesystem"); + // REQUIRES: CAP_SYS_ADMIN + unsafe { libc::mount(src, target, fstype, mountflags, data) } + }; + match ret { + 0 => Ok(()), + _ => Err(crate::ErrnoError(errno::errno()).into()), + } +} + +/// Parse a comma-separated mount options and split out mountflags and filesystem +/// specific options. +fn parse_mount_options(options: impl AsRef<str>) -> (Option<String>, u64) { + use either::Either::*; + debug!("parsing mount options: {}", options.as_ref()); + let (opts, flags) = options + .as_ref() + .split(",") + .map(|o| match o { + "dirsync" => Left(libc::MS_DIRSYNC), + "lazytime" => Left(1 << 25), // MS_LAZYTIME + "mand" => Left(libc::MS_MANDLOCK), + "noatime" => Left(libc::MS_NOATIME), + "nodev" => Left(libc::MS_NODEV), + "nodiratime" => Left(libc::MS_NODIRATIME), + "noexec" => Left(libc::MS_NOEXEC), + "nosuid" => Left(libc::MS_NOSUID), + "relatime" => Left(libc::MS_RELATIME), + "remount" => Left(libc::MS_REMOUNT), + "ro" => Left(libc::MS_RDONLY), + "rw" => Left(0), + "strictatime" => Left(libc::MS_STRICTATIME), + "sync" => Left(libc::MS_SYNCHRONOUS), + "" => Left(0), + o @ _ => Right(o), + }) + .fold((Vec::new(), 0), |(mut opts, flags), next| match next { + Left(f) => (opts, flags | f), + Right(o) => { + opts.push(o); + (opts, flags) + } + }); + + use itertools::Itertools; + ( + if opts.len() == 0 { + None + } else { + Some(opts.iter().join(",")) + }, + flags, + ) +} + +use bch_bindgen::bcachefs; +use std::collections::HashMap; +use uuid::Uuid; + +pub fn probe_filesystems() -> anyhow::Result<HashMap<Uuid, FileSystem>> { + debug!("enumerating udev devices"); + let mut udev = udev::Enumerator::new()?; + + udev.match_subsystem("block")?; // find kernel block devices + + let mut fs_map = HashMap::new(); + let devresults = udev + .scan_devices()? + .into_iter() + .filter_map(|dev| dev.devnode().map(ToOwned::to_owned)); + + for pathbuf in devresults { + match get_super_block_uuid(&pathbuf)? { + Ok((uuid_key, superblock)) => { + let fs = fs_map.entry(uuid_key).or_insert_with(|| { + info!("found bcachefs pool: {}", uuid_key); + FileSystem::new(superblock) + }); + + fs.devices.push(pathbuf); + } + + Err(e) => { + debug!("{}", e); + } + } + } + + info!("found {} filesystems", fs_map.len()); + Ok(fs_map) +} + +// #[tracing_attributes::instrument(skip(dev, fs_map))] +fn get_super_block_uuid( + path: &std::path::Path, +) -> std::io::Result<std::io::Result<(Uuid, bcachefs::bch_sb_handle)>> { + use gag::BufferRedirect; + // Stop libbcachefs from spamming the output + let gag = BufferRedirect::stdout().unwrap(); + + let sb = bch_bindgen::rs::read_super(&path)?; + let super_block = match sb { + Err(e) => { + return Ok(Err(e)); + } + Ok(sb) => sb, + }; + drop(gag); + + let uuid = (&super_block).sb().uuid(); + debug!("bcachefs superblock path={} uuid={}", path.display(), uuid); + + Ok(Ok((uuid, super_block))) +} |