[PATCH 79/79] block: rnull: add zone offline and readonly configfs files

[Andreas Hindborg <a.hindborg@kernel.org>]

Add configfs attributes for managing zone states in the rnull zoned
block device emulation. The `zone_offline` and `zone_readonly`
attributes allow setting specific zones to offline or read-only states,
which is useful for testing how applications handle degraded zones.

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
 drivers/block/rnull/configfs.rs     | 80 +++++++++++++++++++++++++++++++++++
 drivers/block/rnull/disk_storage.rs | 59 +++++++++++++-------------
 drivers/block/rnull/rnull.rs        |  2 +-
 drivers/block/rnull/zoned.rs        | 83 ++++++++++++++++++++++++++-----------
 4 files changed, 168 insertions(+), 56 deletions(-)

diff --git a/drivers/block/rnull/configfs.rs b/drivers/block/rnull/configfs.rs
index 395da68d96dc6..1c0d95ded7e9f 100644
--- a/drivers/block/rnull/configfs.rs
+++ b/drivers/block/rnull/configfs.rs
@@ -125,6 +125,8 @@ fn make_group(
                 max_sectors: 29,
                 virt_boundary: 30,
                 shared_tag_bitmap: 31,
+                zone_offline: 32,
+                zone_readonly: 33,
             ],
         };
 
@@ -639,3 +641,81 @@ fn store(this: &DeviceConfig, page: &[u8]) -> Result {
 configfs_simple_field!(DeviceConfig, 29, max_sectors, u32);
 configfs_simple_bool_field!(DeviceConfig, 30, virt_boundary);
 configfs_simple_bool_field!(DeviceConfig, 31, shared_tag_bitmap);
+
+#[cfg(CONFIG_BLK_DEV_ZONED)]
+fn set_zone_condition(
+    this: &DeviceConfig,
+    sector: u64,
+    cb: impl FnOnce(
+        &crate::zoned::ZoneOptions,
+        &DiskStorage,
+        &mut crate::zoned::ZoneDescriptor,
+    ) -> Result,
+) -> Result {
+    use crate::zoned::ZoneType;
+    let data_guard = this.data.lock();
+    let null_disk = data_guard.disk.as_ref().ok_or(EBUSY)?.queue_data();
+    let storage = &null_disk.storage;
+    let zone_options = &null_disk.zoned;
+    zone_options.enabled.then_some(()).ok_or(EINVAL)?;
+    let mut zone = zone_options.zone(sector)?.lock();
+
+    if zone.kind == ZoneType::Conventional {
+        return Err(EINVAL);
+    }
+
+    cb(zone_options, storage, &mut zone)
+}
+
+#[cfg(CONFIG_BLK_DEV_ZONED)]
+configfs_attribute!(
+    DeviceConfig,
+    32,
+    show: |_this, _page| Ok(0),
+    store: |this,page| {
+        let text = core::str::from_utf8(page)?.trim();
+        let sector = text.parse().map_err(|_| EINVAL)?;
+
+        set_zone_condition(this, sector, |zone_options, storage, zone| {
+            zone_options.offline_zone(storage, zone)
+        })?;
+        Ok(())
+    },
+);
+
+#[cfg(CONFIG_BLK_DEV_ZONED)]
+configfs_attribute!(
+    DeviceConfig,
+    33,
+    show: |_this, _page| Ok(0),
+    store: |this,page| {
+        let text = core::str::from_utf8(page)?.trim();
+        let sector = text.parse().map_err(|_| EINVAL)?;
+
+        set_zone_condition(this, sector, |zone_options, storage, zone| {
+            zone_options.read_only_zone(storage, zone)
+        })?;
+
+        Ok(())
+    },
+);
+
+#[cfg(not(CONFIG_BLK_DEV_ZONED))]
+configfs_attribute!(
+    DeviceConfig,
+    32,
+    show: |this, page| {Ok(0)},
+    store: |this,page| {
+        Err(ENOTSUPP)
+    },
+);
+
+#[cfg(not(CONFIG_BLK_DEV_ZONED))]
+configfs_attribute!(
+    DeviceConfig,
+    33,
+    show: |this, page| {Ok(0)},
+    store: |this,page| {
+        Err(ENOTSUPP)
+    },
+);
diff --git a/drivers/block/rnull/disk_storage.rs b/drivers/block/rnull/disk_storage.rs
index d9f2703957fc0..802e9534ca2a5 100644
--- a/drivers/block/rnull/disk_storage.rs
+++ b/drivers/block/rnull/disk_storage.rs
@@ -65,27 +65,45 @@ pub(crate) fn lock(&self) -> SpinLockGuard<'_, Pin<KBox<TreeContainer>>> {
         self.trees.lock()
     }
 
-    pub(crate) fn discard(
-        &self,
-        hw_data: &Pin<&SpinLock<HwQueueContext>>,
-        mut sector: u64,
-        sectors: u32,
-    ) {
-        let mut tree_guard = self.lock();
-        let mut hw_data_guard = hw_data.lock();
-
-        let mut access = self.access(&mut tree_guard, &mut hw_data_guard, None);
+    pub(crate) fn discard(&self, mut sector: u64, sectors: u32) {
+        let tree_guard = self.lock();
+        let mut cache_guard = tree_guard.cache_tree.lock();
+        let mut disk_guard = tree_guard.cache_tree.lock();
 
         let mut remaining_bytes = sectors_to_bytes(sectors);
 
         while remaining_bytes > 0 {
-            access.free_sector(sector);
+            self.free_sector(&mut cache_guard, &mut disk_guard, sector);
             let processed = remaining_bytes.min(self.block_size);
             sector += Into::<u64>::into(bytes_to_sectors(processed));
             remaining_bytes -= processed;
         }
     }
 
+    fn free_sector_tree(tree_access: &mut xarray::Guard<'_, TreeNode>, sector: u64) {
+        let index = DiskStorageAccess::to_index(sector);
+        if let Some(page) = tree_access.get_mut(index) {
+            page.set_free(sector);
+
+            if page.is_empty() {
+                tree_access.remove(index);
+            }
+        }
+    }
+
+    pub(crate) fn free_sector<'a>(
+        &self,
+        cache_guard: &mut xarray::Guard<'a, TreeNode>,
+        disk_guard: &mut xarray::Guard<'a, TreeNode>,
+        sector: u64,
+    ) {
+        if self.cache_size > 0 {
+            Self::free_sector_tree(cache_guard, sector);
+        }
+
+        Self::free_sector_tree(disk_guard, sector);
+    }
+
     pub(crate) fn flush(&self, hw_data: &Pin<&SpinLock<HwQueueContext>>) {
         let mut tree_guard = self.lock();
         let mut hw_data_guard = hw_data.lock();
@@ -262,25 +280,6 @@ pub(crate) fn get_read_page(&self, sector: u64) -> Option<&NullBlockPage> {
             self.disk_guard.get(index)
         }
     }
-
-    fn free_sector_tree(tree_access: &mut xarray::Guard<'_, TreeNode>, sector: u64) {
-        let index = Self::to_index(sector);
-        if let Some(page) = tree_access.get_mut(index) {
-            page.set_free(sector);
-
-            if page.is_empty() {
-                tree_access.remove(index);
-            }
-        }
-    }
-
-    pub(crate) fn free_sector(&mut self, sector: u64) {
-        if self.disk_storage.cache_size > 0 {
-            Self::free_sector_tree(&mut self.cache_guard, sector);
-        }
-
-        Self::free_sector_tree(&mut self.disk_guard, sector);
-    }
 }
 
 type Tree = XArray<TreeNode>;
diff --git a/drivers/block/rnull/rnull.rs b/drivers/block/rnull/rnull.rs
index 5bf965908ef63..91f8636d74cca 100644
--- a/drivers/block/rnull/rnull.rs
+++ b/drivers/block/rnull/rnull.rs
@@ -739,7 +739,7 @@ fn handle_regular_command(
 
         if self.memory_backed {
             if rq.command() == mq::Command::Discard {
-                self.storage.discard(hw_data, rq.sector(), sectors);
+                self.storage.discard(rq.sector(), sectors);
             } else {
                 self.transfer(hw_data, rq, rq.command(), sectors)?;
             }
diff --git a/drivers/block/rnull/zoned.rs b/drivers/block/rnull/zoned.rs
index 0f15f4cc4e5c3..3b8ebf5449a8d 100644
--- a/drivers/block/rnull/zoned.rs
+++ b/drivers/block/rnull/zoned.rs
@@ -178,7 +178,7 @@ pub(crate) fn handle_zoned_command(
         match rq.command() {
             ZoneAppend | Write => self.zoned_write(hw_data, rq)?,
             ZoneReset | ZoneResetAll | ZoneOpen | ZoneClose | ZoneFinish => {
-                self.zone_management(hw_data, rq)?
+                self.zone_management(rq)?
             }
             _ => self.zoned_read(hw_data, rq)?,
         }
@@ -186,18 +186,14 @@ pub(crate) fn handle_zoned_command(
         Ok(())
     }
 
-    fn zone_management(
-        &self,
-        hw_data: &Pin<&SpinLock<HwQueueContext>>,
-        rq: &mut Owned<mq::Request<Self>>,
-    ) -> Result {
+    fn zone_management(&self, rq: &mut Owned<mq::Request<Self>>) -> Result {
         if rq.command() == mq::Command::ZoneResetAll {
             for zone in self.zoned.zones_iter() {
                 let mut zone = zone.lock();
                 use ZoneCondition::*;
                 match zone.condition {
                     Empty | ReadOnly | Offline => continue,
-                    _ => self.zoned.reset_zone(&self.storage, hw_data, &mut zone)?,
+                    _ => self.zoned.reset_zone(&self.storage, &mut zone)?,
                 }
             }
 
@@ -213,10 +209,10 @@ fn zone_management(
 
         use mq::Command::*;
         match rq.command() {
-            ZoneOpen => self.zoned.open_zone(&mut zone, rq.sector()),
+            ZoneOpen => self.zoned.open_zone(&mut zone),
             ZoneClose => self.zoned.close_zone(&mut zone),
-            ZoneReset => self.zoned.reset_zone(&self.storage, hw_data, &mut zone),
-            ZoneFinish => self.zoned.finish_zone(&mut zone, rq.sector()),
+            ZoneReset => self.zoned.reset_zone(&self.storage, &mut zone),
+            ZoneFinish => self.zoned.finish_zone(&mut zone),
             _ => Err(EIO),
         }
     }
@@ -282,7 +278,7 @@ fn zoned_write(
             if self.zoned.use_accounting() {
                 let mut accounting = self.zoned.accounting.lock();
                 self.zoned
-                    .check_zone_resources(&mut accounting, &mut zone, rq.sector())?;
+                    .check_zone_resources(&mut accounting, &mut zone)?;
 
                 if zone.condition == ZoneCondition::Closed {
                     accounting.closed -= 1;
@@ -365,7 +361,7 @@ fn zone_no(&self, sector: u64) -> usize {
         (sector >> self.size_sectors.ilog2()) as usize
     }
 
-    fn zone(&self, sector: u64) -> Result<&Mutex<ZoneDescriptor>> {
+    pub(crate) fn zone(&self, sector: u64) -> Result<&Mutex<ZoneDescriptor>> {
         self.zones.get(self.zone_no(sector)).ok_or(EINVAL)
     }
 
@@ -418,7 +414,7 @@ fn try_close_implicit_open_zone(&self, accounting: &mut ZoneAccounting, sector:
         Err(EINVAL)
     }
 
-    fn open_zone(&self, zone: &mut ZoneDescriptor, sector: u64) -> Result {
+    fn open_zone(&self, zone: &mut ZoneDescriptor) -> Result {
         if zone.kind == ZoneType::Conventional {
             return Err(EINVAL);
         }
@@ -434,13 +430,13 @@ fn open_zone(&self, zone: &mut ZoneDescriptor, sector: u64) -> Result {
             let mut accounting = self.accounting.lock();
             match zone.condition {
                 Empty => {
-                    self.check_zone_resources(&mut accounting, zone, sector)?;
+                    self.check_zone_resources(&mut accounting, zone)?;
                 }
                 ImplicitOpen => {
                     accounting.implicit_open -= 1;
                 }
                 Closed => {
-                    self.check_zone_resources(&mut accounting, zone, sector)?;
+                    self.check_zone_resources(&mut accounting, zone)?;
                     accounting.closed -= 1;
                 }
                 _ => (),
@@ -457,14 +453,13 @@ fn check_zone_resources(
         &self,
         accounting: &mut ZoneAccounting,
         zone: &mut ZoneDescriptor,
-        sector: u64,
     ) -> Result {
         match zone.condition {
             ZoneCondition::Empty => {
                 self.check_active_zones(accounting)?;
-                self.check_open_zones(accounting, sector)
+                self.check_open_zones(accounting, zone.start_sector)
             }
-            ZoneCondition::Closed => self.check_open_zones(accounting, sector),
+            ZoneCondition::Closed => self.check_open_zones(accounting, zone.start_sector),
             _ => Err(EIO),
         }
     }
@@ -533,7 +528,7 @@ fn close_zone(&self, zone: &mut ZoneDescriptor) -> Result {
         Ok(())
     }
 
-    fn finish_zone(&self, zone: &mut ZoneDescriptor, sector: u64) -> Result {
+    fn finish_zone(&self, zone: &mut ZoneDescriptor) -> Result {
         if zone.kind == ZoneType::Conventional {
             return Err(EINVAL);
         }
@@ -545,12 +540,12 @@ fn finish_zone(&self, zone: &mut ZoneDescriptor, sector: u64) -> Result {
             match zone.condition {
                 Full => return Ok(()),
                 Empty => {
-                    self.check_zone_resources(&mut accounting, zone, sector)?;
+                    self.check_zone_resources(&mut accounting, zone)?;
                 }
                 ImplicitOpen => accounting.implicit_open -= 1,
                 ExplicitOpen => accounting.explicit_open -= 1,
                 Closed => {
-                    self.check_zone_resources(&mut accounting, zone, sector)?;
+                    self.check_zone_resources(&mut accounting, zone)?;
                     accounting.closed -= 1;
                 }
                 _ => return Err(EIO),
@@ -566,7 +561,6 @@ fn finish_zone(&self, zone: &mut ZoneDescriptor, sector: u64) -> Result {
     fn reset_zone(
         &self,
         storage: &crate::disk_storage::DiskStorage,
-        hw_data: &Pin<&SpinLock<HwQueueContext>>,
         zone: &mut ZoneDescriptor,
     ) -> Result {
         if zone.kind == ZoneType::Conventional {
@@ -589,16 +583,55 @@ fn reset_zone(
         zone.condition = ZoneCondition::Empty;
         zone.write_pointer = zone.start_sector;
 
-        storage.discard(hw_data, zone.start_sector, zone.size_sectors);
+        storage.discard(zone.start_sector, zone.size_sectors);
+
+        Ok(())
+    }
+
+    fn set_zone_condition(
+        &self,
+        storage: &crate::disk_storage::DiskStorage,
+        zone: &mut ZoneDescriptor,
+        condition: ZoneCondition,
+    ) -> Result {
+        if zone.condition == condition {
+            zone.condition = ZoneCondition::Empty;
+            zone.write_pointer = zone.start_sector;
+            storage.discard(zone.start_sector, zone.size_sectors);
+        } else {
+            if matches!(
+                zone.condition,
+                ZoneCondition::ReadOnly | ZoneCondition::Offline
+            ) {
+                self.finish_zone(zone)?;
+            }
 
+            zone.condition = ZoneCondition::Offline;
+            zone.write_pointer = u64::MAX;
+        }
         Ok(())
     }
+    pub(crate) fn offline_zone(
+        &self,
+        storage: &crate::disk_storage::DiskStorage,
+        zone: &mut ZoneDescriptor,
+    ) -> Result {
+        self.set_zone_condition(storage, zone, ZoneCondition::Offline)
+    }
+
+    pub(crate) fn read_only_zone(
+        &self,
+        storage: &crate::disk_storage::DiskStorage,
+        zone: &mut ZoneDescriptor,
+    ) -> Result {
+        self.set_zone_condition(storage, zone, ZoneCondition::ReadOnly)
+    }
 }
 
 pub(crate) struct ZoneDescriptor {
     start_sector: u64,
     size_sectors: u32,
-    kind: ZoneType,
+    pub(crate) kind: ZoneType,
     capacity_sectors: u32,
     write_pointer: u64,
     condition: ZoneCondition,
@@ -626,7 +659,7 @@ fn check_bounds_read(&self, sector: u64, sectors: u32) -> Result {
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
 #[repr(u32)]
-enum ZoneType {
+pub(crate) enum ZoneType {
     Conventional = bindings::blk_zone_type_BLK_ZONE_TYPE_CONVENTIONAL,
     SequentialWriteRequired = bindings::blk_zone_type_BLK_ZONE_TYPE_SEQWRITE_REQ,
     #[expect(dead_code)]

-- 
2.51.2