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Message-Id: <20230625121657.3631109-5-changxian.cqs@antgroup.com>
Date: Sun, 25 Jun 2023 20:16:53 +0800
From: "Qingsong Chen" <changxian.cqs@...group.com>
To: linux-kernel@...r.kernel.org
Cc: "田洪亮" <tate.thl@...group.com>,
"Qingsong Chen" <changxian.cqs@...group.com>,
"Miguel Ojeda" <ojeda@...nel.org>,
"Alex Gaynor" <alex.gaynor@...il.com>,
"Wedson Almeida Filho" <wedsonaf@...il.com>,
"Boqun Feng" <boqun.feng@...il.com>, "Gary Guo" <gary@...yguo.net>,
"Björn Roy Baron" <bjorn3_gh@...tonmail.com>,
"Benno Lossin" <benno.lossin@...ton.me>,
<rust-for-linux@...r.kernel.org>
Subject: [RFC PATCH 4/8] rust: kernel: add some info handler TargetOperations
- Add `status`/`message` to retrieve info of targets.
- Add `report_zones` to propagate report zones command
to underlying devices.
Signed-off-by: Qingsong Chen <changxian.cqs@...group.com>
---
rust/kernel/device_mapper.rs | 149 ++++++++++++++++++++++++++++++++++-
1 file changed, 148 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/device_mapper.rs b/rust/kernel/device_mapper.rs
index aeda12245171..9a62208fda56 100644
--- a/rust/kernel/device_mapper.rs
+++ b/rust/kernel/device_mapper.rs
@@ -10,7 +10,7 @@
use crate::error::to_result;
use crate::prelude::*;
-use crate::str::CStr;
+use crate::str::{CStr, CString};
use crate::types::Opaque;
/// Declare operations that a device mapper target can do.
@@ -100,6 +100,24 @@ fn resume(t: &mut Target<Self>) {
fn busy(t: &mut Target<Self>) -> bool {
unimplemented!()
}
+
+ /// Return the target status.
+ #[allow(unused)]
+ fn status(t: &mut Target<Self>, type_: StatusType, flags: StatusFlags) -> Option<CString> {
+ unimplemented!()
+ }
+
+ /// Handle messages to the target.
+ #[allow(unused)]
+ fn message(t: &mut Target<Self>, args: Args) -> Result<CString> {
+ unimplemented!()
+ }
+
+ /// Propagate report zones command to underlying devices.
+ #[allow(unused)]
+ fn report_zones(t: &mut Target<Self>, args: &mut [ReportZonesArgs]) -> Result {
+ unimplemented!()
+ }
}
/// Wrap the kernel struct `target_type`.
@@ -172,6 +190,9 @@ pub fn register<T: TargetOperations>(
(HAS_PRERESUME, preresume, dm_preresume_fn),
(HAS_RESUME, resume, dm_resume_fn),
(HAS_BUSY, busy, dm_busy_fn),
+ (HAS_STATUS, status, dm_status_fn),
+ (HAS_MESSAGE, message, dm_message_fn),
+ (HAS_REPORT_ZONES, report_zones, dm_report_zones_fn),
);
to_result(bindings::dm_register_target(tt))
@@ -327,6 +348,69 @@ impl TargetType {
let t = unsafe { Target::borrow_mut(ti) };
T::busy(t) as _
}
+ unsafe extern "C" fn dm_status_fn<T: TargetOperations>(
+ ti: *mut bindings::dm_target,
+ status_type: bindings::status_type_t,
+ status_flags: core::ffi::c_uint,
+ result: *mut core::ffi::c_char,
+ maxlen: core::ffi::c_uint,
+ ) {
+ // SAFETY: the kernel should pass valid `dm_target` pointer.
+ let t = unsafe { Target::borrow_mut(ti) };
+ if let Some(s) = T::status(t, status_type.into(), status_flags.into()) {
+ let count = s.len_with_nul().min(maxlen as _);
+ // SAFETY: the kernel should pass valid `result` pointer, and
+ // `count` is not greater than `maxlen`.
+ unsafe {
+ core::ptr::copy(s.as_char_ptr(), result, count);
+ }
+ }
+ }
+ unsafe extern "C" fn dm_message_fn<T: TargetOperations>(
+ ti: *mut bindings::dm_target,
+ argc: core::ffi::c_uint,
+ argv: *mut *mut core::ffi::c_char,
+ result: *mut core::ffi::c_char,
+ maxlen: core::ffi::c_uint,
+ ) -> core::ffi::c_int {
+ // SAFETY: the kernel splits arguments by `dm_split_args`, then pass
+ // suitable `argc` and `argv` to `dm_ctr_fn`. If `argc` is not zero,
+ // `argv` is non-null and valid.
+ let args = unsafe { Args::new(argc, argv) };
+
+ // SAFETY: the kernel should pass valid `dm_target` pointer.
+ let t = unsafe { Target::borrow_mut(ti) };
+ T::message(t, args).map_or_else(
+ |e| e.to_errno(),
+ // SAFETY: the kernel should pass valid `result` pointer, and
+ // `count` is not greater than `maxlen`.
+ |ret| unsafe {
+ let count = ret.len_with_nul().min(maxlen as _);
+ core::ptr::copy(ret.as_char_ptr(), result, count);
+ 0
+ },
+ )
+ }
+ unsafe extern "C" fn dm_report_zones_fn<T: TargetOperations>(
+ ti: *mut bindings::dm_target,
+ args: *mut bindings::dm_report_zones_args,
+ nr_zones: core::ffi::c_uint,
+ ) -> core::ffi::c_int {
+ // SAFETY: the kernel should pass valid `dm_target` pointer.
+ let t = unsafe { Target::borrow_mut(ti) };
+
+ let args = if nr_zones > 0 {
+ // SAFETY: the kernel should pass valid `args`, if `nr_zones`
+ // is not zero.
+ unsafe {
+ let first = ReportZonesArgs::borrow_mut(args);
+ core::slice::from_raw_parts_mut(first as _, nr_zones as _)
+ }
+ } else {
+ &mut []
+ };
+ T::report_zones(t, args).map_or_else(|e| e.to_errno(), |_| 0)
+ }
}
/// Wrap the kernel struct `dm_target`.
@@ -511,6 +595,69 @@ unsafe fn borrow_mut<'a>(ptr: *mut bindings::map_info) -> &'a mut Self {
}
}
+/// Define target status types.
+#[repr(u32)]
+pub enum StatusType {
+ /// Request for some general info.
+ Info,
+
+ /// Request for more detailed info.
+ Table,
+
+ /// Request for some integrity info.
+ Ima,
+
+ /// Undefined.
+ Undefined,
+}
+
+impl From<u32> for StatusType {
+ fn from(value: u32) -> Self {
+ match value {
+ bindings::status_type_t_STATUSTYPE_INFO => Self::Info,
+ bindings::status_type_t_STATUSTYPE_TABLE => Self::Table,
+ bindings::status_type_t_STATUSTYPE_IMA => Self::Ima,
+ _ => Self::Undefined,
+ }
+ }
+}
+
+/// Define target status flags.
+#[repr(u32)]
+pub enum StatusFlags {
+ /// See `DM_STATUS_NOFLUSH_FLAG`.
+ NoFlush = 1 << 0,
+
+ /// Undefined.
+ Undefined,
+}
+
+impl From<u32> for StatusFlags {
+ fn from(value: u32) -> Self {
+ match value {
+ 0 => Self::NoFlush,
+ _ => Self::Undefined,
+ }
+ }
+}
+
+/// Wrap the kernel struct `dm_report_zones_args`.
+pub struct ReportZonesArgs(Opaque<bindings::dm_report_zones_args>);
+
+impl ReportZonesArgs {
+ unsafe fn borrow_mut<'a>(ptr: *mut bindings::dm_report_zones_args) -> &'a mut Self {
+ // SAFETY: the caller should pass a valid `ptr`.
+ unsafe { &mut *(ptr as *mut Self) }
+ }
+
+ /// Return the next sector.
+ pub fn next_sector(&self) -> usize {
+ // SAFETY: `self.0` is borrowed form foreign pointer,
+ // should be valid.
+ unsafe { (*self.0.get()).next_sector as _ }
+ }
+}
+
/// Wrap the `c_char` arguments, which yields `CStr`.
pub struct Args {
argc: core::ffi::c_uint,
--
2.40.1
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