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Message-Id: <20230625121657.3631109-8-changxian.cqs@antgroup.com>
Date: Sun, 25 Jun 2023 20:16:56 +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 7/8] rust: kernel: prepare to implement dm target in Rust
- Add some methods to set fields in `dm_target`.
- Add some methods to `TargetDevice` to operate on
the underlying devices.
- Add some methods to dummy `bio`, for remapping.
Signed-off-by: Qingsong Chen <changxian.cqs@...group.com>
---
rust/helpers.c | 7 ++
rust/kernel/device_mapper.rs | 237 +++++++++++++++++++++++++++++++++++
2 files changed, 244 insertions(+)
diff --git a/rust/helpers.c b/rust/helpers.c
index bb594da56137..706541b58432 100644
--- a/rust/helpers.c
+++ b/rust/helpers.c
@@ -27,6 +27,7 @@
#include <linux/spinlock.h>
#include <linux/sched/signal.h>
#include <linux/wait.h>
+#include <linux/bio.h>
__noreturn void rust_helper_BUG(void)
{
@@ -135,6 +136,12 @@ void rust_helper_put_task_struct(struct task_struct *t)
}
EXPORT_SYMBOL_GPL(rust_helper_put_task_struct);
+void rust_helper_bio_set_dev(struct bio *bio, struct block_device *bdev)
+{
+ bio_set_dev(bio, bdev);
+}
+EXPORT_SYMBOL_GPL(rust_helper_bio_set_dev);
+
/*
* We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type
* as the Rust `usize` type, so we can use it in contexts where Rust
diff --git a/rust/kernel/device_mapper.rs b/rust/kernel/device_mapper.rs
index d2c9d0a5bcd5..fa9b33d529b7 100644
--- a/rust/kernel/device_mapper.rs
+++ b/rust/kernel/device_mapper.rs
@@ -671,6 +671,124 @@ pub fn get_device(&mut self, path: &CStr) -> Result<TargetDevice<T>> {
}
}
}
+
+ /// Return maximum size (in sectors) of I/O submitted to the target.
+ pub fn max_io_len(&self) -> usize {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { (*self.opaque.get()).max_io_len as _ }
+ }
+
+ /// Set maximum size (in sectors) of I/O submitted to the target.
+ pub fn set_max_io_len(&mut self, len: usize) -> Result {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ to_result(bindings::dm_set_target_max_io_len(
+ self.opaque.get(),
+ len as _,
+ ))
+ }
+ }
+
+ /// Return the number of zero-length barrier bios that will be submitted
+ /// to the target for the purpose of flushing cache.
+ pub fn num_flush_bios(&self) -> usize {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { (*self.opaque.get()).num_flush_bios as _ }
+ }
+
+ /// Set the number of zero-length barrier bios that will be submitted
+ /// to the target for the purpose of flushing cache.
+ pub fn set_num_flush_bios(&mut self, num: usize) {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ (*self.opaque.get()).num_flush_bios = num as _;
+ }
+ }
+
+ /// Return the number of discard bios.
+ pub fn num_discard_bios(&self) -> usize {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { (*self.opaque.get()).num_discard_bios as _ }
+ }
+
+ /// Set the number of discard bios.
+ pub fn set_num_discard_bios(&mut self, num: usize) {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ (*self.opaque.get()).num_discard_bios = num as _;
+ }
+ }
+
+ /// Return the number of secure erase bios.
+ pub fn num_secure_erase_bios(&self) -> usize {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { (*self.opaque.get()).num_secure_erase_bios as _ }
+ }
+
+ /// Set the number of secure erase bios.
+ pub fn set_num_secure_erase_bios(&mut self, num: usize) {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ (*self.opaque.get()).num_secure_erase_bios = num as _;
+ }
+ }
+
+ /// Return the number of WRITE ZEROES bios.
+ pub fn num_write_zeroes_bios(&self) -> usize {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { (*self.opaque.get()).num_write_zeroes_bios as _ }
+ }
+
+ /// Set the number of WRITE ZEROES bios.
+ pub fn set_num_write_zeroes_bios(&mut self, num: usize) {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ (*self.opaque.get()).num_write_zeroes_bios = num as _;
+ }
+ }
+
+ /// Return the minimum number of extra bytes allocated in each io
+ /// for the target to use.
+ pub fn per_io_data_size(&self) -> usize {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { (*self.opaque.get()).per_io_data_size as _ }
+ }
+
+ /// Set the minimum number of extra bytes allocated in each io
+ /// for the target to use.
+ pub fn set_per_io_data_size(&mut self, size: usize) {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ (*self.opaque.get()).per_io_data_size = size as _;
+ }
+ }
+
+ /// Set an error string for the target, could be used
+ /// by [`TargetOperations::ctr`].
+ pub fn set_error(&mut self, err: &CStr) {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe {
+ (*self.opaque.get()).error = err.as_char_ptr() as _;
+ }
+ }
+
+ /// Check if the target is suspended.
+ pub fn suspended(&self) -> bool {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { bindings::dm_suspended(self.opaque.get()) != 0 }
+ }
+
+ /// Check if the target is post_suspending.
+ pub fn post_suspending(&self) -> bool {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { bindings::dm_post_suspending(self.opaque.get()) != 0 }
+ }
+
+ /// Check if the target is noflush_suspending.
+ pub fn noflush_suspending(&self) -> bool {
+ // SAFETY: `self.opaque` is borrowed from foreign pointer, should be valid.
+ unsafe { bindings::dm_noflush_suspending(self.opaque.get()) != 0 }
+ }
}
/// Represent an underlying device of a device mapper target.
@@ -721,6 +839,100 @@ pub fn device_sectors(&self) -> usize {
// SAFETY: the `from_raw` caller should pass valid `dev` pointer.
unsafe { (*(*self.dev.as_ptr()).bdev).bd_nr_sectors as _ }
}
+
+ /// Return [NonNull<TargetDevice>].
+ pub fn as_ptr(&mut self) -> NonNull<Self> {
+ // SAFETY: `self` is non-null and valid.
+ unsafe { NonNull::new_unchecked(self as *mut Self) }
+ }
+
+ /// Propagate report zones command to underlying devices.
+ #[cfg(CONFIG_BLK_DEV_ZONED)]
+ pub fn report_zones(
+ &self,
+ start: usize,
+ sector: usize,
+ args: &mut [ReportZonesArgs],
+ ) -> Result {
+ // SAFETY: the `from_raw` caller should pass valid `dev` pointer.
+ unsafe {
+ let bdev = (*self.dev.as_ptr()).bdev;
+ let ptr = args.as_mut_ptr() as *mut bindings::dm_report_zones_args;
+ to_result(bindings::dm_report_zones(
+ bdev,
+ start as _,
+ sector as _,
+ ptr,
+ args.len() as _,
+ ))
+ }
+ }
+
+ /// Translate a device-relative logical-page-offset into an
+ /// absolute physical pfn.
+ ///
+ /// Return the `addr` and the `pages` available for `DAX` at
+ /// that pfn, if success.
+ #[cfg(CONFIG_FS_DAX)]
+ pub fn dax_direct_access(
+ &mut self,
+ pgoff: usize,
+ nr_pages: usize,
+ mode: DaxMode,
+ ) -> Result<(usize, Range<usize>)> {
+ let mut kaddr = core::ptr::null_mut();
+ let mut pfn = bindings::pfn_t::default();
+
+ // SAFETY: the `from_raw` caller should pass valid `dev` pointer.
+ let count = unsafe {
+ let dax_dev = (*self.dev.as_ptr()).dax_dev;
+ bindings::dax_direct_access(
+ dax_dev,
+ pgoff as _,
+ nr_pages as _,
+ mode as _,
+ &mut kaddr,
+ &mut pfn,
+ )
+ };
+
+ if count < 0 {
+ Err(Error::from_errno(count as _))
+ } else {
+ let pages = Range {
+ start: pfn.val as usize,
+ end: (pfn.val as usize) + (count as usize),
+ };
+ Ok((kaddr as _, pages))
+ }
+ }
+
+ /// Zero page range.
+ #[cfg(CONFIG_FS_DAX)]
+ pub fn dax_zero_page_range(&mut self, pgoff: usize, nr_pages: usize) -> Result {
+ // SAFETY: the `from_raw` caller should pass valid `dev` pointer.
+ unsafe {
+ let dax_dev = (*self.dev.as_ptr()).dax_dev;
+ to_result(bindings::dax_zero_page_range(dax_dev, pgoff as _, nr_pages))
+ }
+ }
+
+ /// Recover a poisoned range by DAX device driver capable of
+ /// clearing poison.
+ #[cfg(CONFIG_FS_DAX)]
+ pub fn dax_recovery_write(
+ &mut self,
+ iov_iter: Pin<&mut IovIter>,
+ pgoff: usize,
+ region: Range<usize>,
+ ) -> usize {
+ // SAFETY: the `from_raw` caller should pass `dev` pointer.
+ unsafe {
+ let dax_dev = (*self.dev.as_ptr()).dax_dev;
+ let i = iov_iter.opaque.get();
+ bindings::dax_recovery_write(dax_dev, pgoff as _, region.start as _, region.len(), i)
+ }
+ }
}
impl<T: TargetOperations> Drop for TargetDevice<T> {
@@ -919,6 +1131,31 @@ fn op_and_flags(&self) -> u32 {
pub fn is_write(&self) -> bool {
self.op_and_flags() & bindings::req_op_REQ_OP_WRITE != 0
}
+
+ /// Return the start sector of bio.
+ pub fn sector(&self) -> usize {
+ // SAFETY: the `from_raw` caller should pass valid `bio`, so
+ // `self.opaque` is valid too.
+ unsafe { (*self.opaque.get()).bi_iter.bi_sector as _ }
+ }
+
+ /// Set the start sector of bio.
+ pub fn set_sector(&mut self, sector: usize) {
+ // SAFETY: the `from_raw` caller should pass valid `bio`, so
+ // `self.opaque` is valid too.
+ unsafe {
+ (*self.opaque.get()).bi_iter.bi_sector = sector as _;
+ }
+ }
+
+ /// Set the block device of bio.
+ pub fn set_dev<T: TargetOperations>(&mut self, td: &TargetDevice<T>) {
+ // SAFETY: the `from_raw` caller should pass valid `bio`, so
+ // `self.opaque` is valid too.
+ unsafe {
+ bindings::bio_set_dev(self.opaque.get(), (*td.dev.as_ptr()).bdev);
+ }
+ }
}
/// Wrap the kernel struct `request`.
--
2.40.1
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