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-rw-r--r--src/commands/cmd_mount.rs251
1 files changed, 251 insertions, 0 deletions
diff --git a/src/commands/cmd_mount.rs b/src/commands/cmd_mount.rs
new file mode 100644
index 00000000..b120c91e
--- /dev/null
+++ b/src/commands/cmd_mount.rs
@@ -0,0 +1,251 @@
+use atty::Stream;
+use bch_bindgen::{bcachefs, bcachefs::bch_sb_handle, opt_set};
+use log::{info, debug, error, LevelFilter};
+use clap::{Parser};
+use uuid::Uuid;
+use std::path::PathBuf;
+use crate::key;
+use crate::key::KeyLocation;
+use std::ffi::{CString, c_char, c_void};
+use std::os::unix::ffi::OsStrExt;
+
+fn mount_inner(
+ src: String,
+ target: impl AsRef<std::path::Path>,
+ fstype: &str,
+ mountflags: libc::c_ulong,
+ data: Option<String>,
+) -> anyhow::Result<()> {
+
+ // 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>, libc::c_ulong) {
+ 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)
+ }
+ });
+
+ (
+ if opts.len() == 0 {
+ None
+ } else {
+ Some(opts.join(","))
+ },
+ flags,
+ )
+}
+
+fn mount(
+ device: String,
+ target: impl AsRef<std::path::Path>,
+ options: impl AsRef<str>,
+) -> anyhow::Result<()> {
+ let (data, mountflags) = parse_mount_options(options);
+
+ info!(
+ "mounting bcachefs filesystem, {}",
+ target.as_ref().display()
+ );
+ mount_inner(device, target, "bcachefs", mountflags, data)
+}
+
+fn read_super_silent(path: &std::path::PathBuf) -> anyhow::Result<bch_sb_handle> {
+ // Stop libbcachefs from spamming the output
+ let _gag = gag::BufferRedirect::stdout().unwrap();
+
+ let mut opts = bcachefs::bch_opts::default();
+ opt_set!(opts, noexcl, 1);
+
+ bch_bindgen::rs::read_super_opts(&path, opts)
+}
+
+fn get_devices_by_uuid(uuid: Uuid) -> anyhow::Result<Vec<(PathBuf, bch_sb_handle)>> {
+ debug!("enumerating udev devices");
+ let mut udev = udev::Enumerator::new()?;
+
+ udev.match_subsystem("block")?;
+
+ let devs = udev
+ .scan_devices()?
+ .into_iter()
+ .filter_map(|dev| dev.devnode().map(ToOwned::to_owned))
+ .map(|dev| (dev.clone(), read_super_silent(&dev)))
+ .filter_map(|(dev, sb)| sb.ok().map(|sb| (dev, sb)))
+ .filter(|(_, sb)| sb.sb().uuid() == uuid)
+ .collect();
+ Ok(devs)
+}
+
+/// Mount a bcachefs filesystem by its UUID.
+#[derive(Parser, Debug)]
+#[command(author, version, about, long_about = None)]
+pub struct Cli {
+ /// Where the password would be loaded from.
+ ///
+ /// Possible values are:
+ /// "fail" - don't ask for password, fail if filesystem is encrypted;
+ /// "wait" - wait for password to become available before mounting;
+ /// "ask" - prompt the user for password;
+ #[arg(short, long, default_value = "ask", verbatim_doc_comment)]
+ key_location: KeyLocation,
+
+ /// Device, or UUID=<UUID>
+ dev: String,
+
+ /// Where the filesystem should be mounted. If not set, then the filesystem
+ /// won't actually be mounted. But all steps preceeding mounting the
+ /// filesystem (e.g. asking for passphrase) will still be performed.
+ mountpoint: Option<std::path::PathBuf>,
+
+ /// Mount options
+ #[arg(short, default_value = "")]
+ options: String,
+
+ /// Force color on/off. Default: autodetect tty
+ #[arg(short, long, action = clap::ArgAction::Set, default_value_t=atty::is(Stream::Stdout))]
+ colorize: bool,
+
+ /// Verbose mode
+ #[arg(short, long, action = clap::ArgAction::Count)]
+ verbose: u8,
+}
+
+fn devs_str_sbs_from_uuid(uuid: String) -> anyhow::Result<(String, Vec<bch_sb_handle>)> {
+ debug!("enumerating devices with UUID {}", uuid);
+
+ let devs_sbs = Uuid::parse_str(&uuid)
+ .map(|uuid| get_devices_by_uuid(uuid))??;
+
+ let devs_str = devs_sbs
+ .iter()
+ .map(|(dev, _)| dev.to_str().unwrap())
+ .collect::<Vec<_>>()
+ .join(":");
+
+ let sbs: Vec<bch_sb_handle> = devs_sbs.iter().map(|(_, sb)| *sb).collect();
+
+ Ok((devs_str, sbs))
+
+}
+
+fn cmd_mount_inner(opt: Cli) -> anyhow::Result<()> {
+ let (devs, sbs) = if opt.dev.starts_with("UUID=") {
+ let uuid = opt.dev.replacen("UUID=", "", 1);
+ devs_str_sbs_from_uuid(uuid)?
+ } else if opt.dev.starts_with("OLD_BLKID_UUID=") {
+ let uuid = opt.dev.replacen("OLD_BLKID_UUID=", "", 1);
+ devs_str_sbs_from_uuid(uuid)?
+ } else {
+ let mut sbs = Vec::new();
+
+ for dev in opt.dev.split(':') {
+ let dev = PathBuf::from(dev);
+ sbs.push(read_super_silent(&dev)?);
+ }
+
+ (opt.dev, sbs)
+ };
+
+ if sbs.len() == 0 {
+ Err(anyhow::anyhow!("No device found from specified parameters"))?;
+ } else if unsafe { bcachefs::bch2_sb_is_encrypted(sbs[0].sb) } {
+ key::prepare_key(&sbs[0], opt.key_location)?;
+ }
+
+ if let Some(mountpoint) = opt.mountpoint {
+ info!(
+ "mounting with params: device: {}, target: {}, options: {}",
+ devs,
+ mountpoint.to_string_lossy(),
+ &opt.options
+ );
+
+ mount(devs, mountpoint, &opt.options)?;
+ } else {
+ info!(
+ "would mount with params: device: {}, options: {}",
+ devs,
+ &opt.options
+ );
+ }
+
+ Ok(())
+}
+
+pub fn cmd_mount(mut argv: Vec<String>, symlink_cmd: Option<&str>) -> i32 {
+ // If the bcachefs tool is being called as "bcachefs mount dev ..." (as opposed to via a
+ // symlink like "/usr/sbin/mount.bcachefs dev ...", then we need to pop the 0th argument
+ // ("bcachefs") since the CLI parser here expects the device at position 1.
+ if symlink_cmd.is_none() {
+ argv.remove(0);
+ }
+
+ let opt = Cli::parse_from(argv);
+
+ // @TODO : more granular log levels via mount option
+ log::set_max_level(match opt.verbose {
+ 0 => LevelFilter::Warn,
+ 1 => LevelFilter::Trace,
+ 2_u8..=u8::MAX => todo!(),
+ });
+
+ colored::control::set_override(opt.colorize);
+ if let Err(e) = cmd_mount_inner(opt) {
+ error!("Fatal error: {}", e);
+ 1
+ } else {
+ info!("Successfully mounted");
+ 0
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-28 21:12:57 +0000