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|
use std::path::Path;
use bch_bindgen::c::{
bcache_fs_close, bcache_fs_open, bch_ioctl_subvolume, bchfs_handle, BCH_IOCTL_SUBVOLUME_CREATE,
BCH_IOCTL_SUBVOLUME_DESTROY, BCH_SUBVOL_SNAPSHOT_CREATE,
};
use bch_bindgen::path_to_cstr;
use errno::Errno;
/// A handle to a bcachefs filesystem
/// This can be used to send [`libc::ioctl`] to the underlying filesystem.
pub(crate) struct BcachefsHandle {
inner: bchfs_handle,
}
impl BcachefsHandle {
/// Opens a bcachefs filesystem and returns its handle
/// TODO(raitobezarius): how can this not be faillible?
pub(crate) unsafe fn open<P: AsRef<Path>>(path: P) -> Self {
let path = path_to_cstr(path);
Self {
inner: bcache_fs_open(path.as_ptr()),
}
}
}
/// I/O control commands that can be sent to a bcachefs filesystem
/// Those are non-exhaustive
#[repr(u32)]
#[non_exhaustive]
pub enum BcachefsIoctl {
SubvolumeCreate = BCH_IOCTL_SUBVOLUME_CREATE,
SubvolumeDestroy = BCH_IOCTL_SUBVOLUME_DESTROY,
}
/// I/O control commands payloads
#[non_exhaustive]
pub enum BcachefsIoctlPayload {
Subvolume(bch_ioctl_subvolume),
}
impl From<&BcachefsIoctlPayload> for *const libc::c_void {
fn from(value: &BcachefsIoctlPayload) -> Self {
match value {
BcachefsIoctlPayload::Subvolume(p) => p as *const _ as *const libc::c_void,
}
}
}
impl BcachefsHandle {
/// Type-safe [`libc::ioctl`] for bcachefs filesystems
pub fn ioctl(
&self,
request: BcachefsIoctl,
payload: &BcachefsIoctlPayload,
) -> Result<(), Errno> {
let payload_ptr: *const libc::c_void = payload.into();
let ret = unsafe { libc::ioctl(self.inner.ioctl_fd, request as libc::Ioctl, payload_ptr) };
if ret == -1 {
Err(errno::errno())
} else {
Ok(())
}
}
/// Create a subvolume for this bcachefs filesystem
/// at the given path
pub fn create_subvolume<P: AsRef<Path>>(&self, dst: P) -> Result<(), Errno> {
let dst = path_to_cstr(dst);
self.ioctl(
BcachefsIoctl::SubvolumeCreate,
&BcachefsIoctlPayload::Subvolume(bch_ioctl_subvolume {
dirfd: libc::AT_FDCWD as u32,
mode: 0o777,
dst_ptr: dst.as_ptr() as u64,
..Default::default()
}),
)
}
/// Delete the subvolume at the given path
/// for this bcachefs filesystem
pub fn delete_subvolume<P: AsRef<Path>>(&self, dst: P) -> Result<(), Errno> {
let dst = path_to_cstr(dst);
self.ioctl(
BcachefsIoctl::SubvolumeDestroy,
&BcachefsIoctlPayload::Subvolume(bch_ioctl_subvolume {
dirfd: libc::AT_FDCWD as u32,
mode: 0o777,
dst_ptr: dst.as_ptr() as u64,
..Default::default()
}),
)
}
/// Snapshot a subvolume for this bcachefs filesystem
/// at the given path
pub fn snapshot_subvolume<P: AsRef<Path>>(
&self,
extra_flags: u32,
src: Option<P>,
dst: P,
) -> Result<(), Errno> {
let src = src.map(|src| path_to_cstr(src));
let dst = path_to_cstr(dst);
let res = self.ioctl(
BcachefsIoctl::SubvolumeCreate,
&BcachefsIoctlPayload::Subvolume(bch_ioctl_subvolume {
flags: BCH_SUBVOL_SNAPSHOT_CREATE | extra_flags,
dirfd: libc::AT_FDCWD as u32,
mode: 0o777,
src_ptr: src.as_ref().map_or(0, |x| x.as_ptr() as u64),
//src_ptr: if let Some(src) = src { src.as_ptr() } else { std::ptr::null() } as u64,
dst_ptr: dst.as_ptr() as u64,
..Default::default()
}),
);
drop(src);
drop(dst);
res
}
}
impl Drop for BcachefsHandle {
fn drop(&mut self) {
unsafe { bcache_fs_close(self.inner) };
}
}
|
