tape/changer: refactor marking of import/export slots from config

we did this for 'mtx', but missed it for the sg_pt_changer code
refactor it into the MtxStatus strut, and call it from both
code paths

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>

src/tape/changer/mod.rs

@@ -10,10 +10,16 @@ pub mod mtx;
 mod online_status_map;
 pub use online_status_map::*;
 
+use std::collections::HashSet;
+
 use anyhow::{bail, Error};
 use serde::{Serialize, Deserialize};
+use serde_json::Value;
+
+use proxmox::api::schema::parse_property_string;
 
 use crate::api2::types::{
+    SLOT_ARRAY_SCHEMA,
     ScsiTapeChanger,
     LinuxTapeDrive,
 };
@@ -124,6 +130,29 @@ impl MtxStatus {
         }
         free_slot
     }
+
+    pub fn mark_import_export_slots(&mut self, config: &ScsiTapeChanger) -> Result<(), Error>{
+        let mut export_slots: HashSet<u64> = HashSet::new();
+
+        if let Some(slots) = &config.export_slots {
+            let slots: Value = parse_property_string(&slots, &SLOT_ARRAY_SCHEMA)?;
+            export_slots = slots
+                .as_array()
+                .unwrap()
+                .iter()
+                .filter_map(|v| v.as_u64())
+                .collect();
+        }
+
+        for (i, entry) in self.slots.iter_mut().enumerate() {
+            let slot = i as u64 + 1;
+            if export_slots.contains(&slot) {
+                entry.import_export = true; // mark as IMPORT/EXPORT
+            }
+        }
+
+        Ok(())
+    }
 }
 
 /// Interface to SCSI changer devices
@@ -373,8 +402,7 @@ impl ScsiMediaChange for ScsiTapeChanger {
         if USE_MTX {
             mtx::mtx_status(&self)
         } else {
-            let mut file = sg_pt_changer::open(&self.path)?;
-            sg_pt_changer::read_element_status(&mut file)
+            sg_pt_changer::status(&self)
         }
     }
 

src/tape/changer/mtx/mtx_wrapper.rs

@@ -1,45 +1,19 @@
-use std::collections::HashSet;
-
 use anyhow::Error;
 use serde_json::Value;
 
-use proxmox::{
-    api::schema::parse_property_string,
-};
-
 use crate::{
     tools::run_command,
-    api2::types::{
-        SLOT_ARRAY_SCHEMA,
-        ScsiTapeChanger,
-    },
-    tape::{
-        changer::{
-            MtxStatus,
-            mtx::{
-                parse_mtx_status,
-            },
-        },
+    api2::types::ScsiTapeChanger,
+    tape::changer::{
+        MtxStatus,
+        mtx::parse_mtx_status,
     },
 };
 
 /// Run 'mtx status' and return parsed result.
 pub fn mtx_status(config: &ScsiTapeChanger) -> Result<MtxStatus, Error> {
-
     let path = &config.path;
 
-    let mut export_slots: HashSet<u64> = HashSet::new();
-
-    if let Some(slots) = &config.export_slots {
-        let slots: Value = parse_property_string(&slots, &SLOT_ARRAY_SCHEMA)?;
-        export_slots = slots
-            .as_array()
-            .unwrap()
-            .iter()
-            .filter_map(|v| v.as_u64())
-            .collect();
-    }
-
     let mut command = std::process::Command::new("mtx");
     command.args(&["-f", path, "status"]);
 
@@ -47,12 +21,7 @@ pub fn mtx_status(config: &ScsiTapeChanger) -> Result<MtxStatus, Error> {
 
     let mut status = parse_mtx_status(&output)?;
 
-    for (i, entry) in status.slots.iter_mut().enumerate() {
-        let slot = i as u64 + 1;
-        if export_slots.contains(&slot) {
-            entry.import_export = true; // mark as IMPORT/EXPORT
-        }
-    }
+    status.mark_import_export_slots(&config)?;
 
     Ok(status)
 }

src/tape/changer/sg_pt_changer.rs

@@ -31,6 +31,7 @@ use crate::{
         scsi_ascii_to_string,
         scsi_inquiry,
     },
+    api2::types::ScsiTapeChanger,
 };
 
 const SCSI_CHANGER_DEFAULT_TIMEOUT: usize = 60*5; // 5 minutes
@@ -397,6 +398,21 @@ pub fn read_element_status<F: AsRawFd>(file: &mut F) -> Result<MtxStatus, Error>
     Ok(status)
 }
 
+/// Read status and map import-export slots from config
+pub fn status(config: &ScsiTapeChanger) -> Result<MtxStatus, Error> {
+    let path = &config.path;
+
+    let mut file = open(path)
+        .map_err(|err| format_err!("error opening '{}': {}", path, err))?;
+    let mut status = read_element_status(&mut file)
+        .map_err(|err| format_err!("error reading element status: {}", err))?;
+
+    status.mark_import_export_slots(&config)?;
+
+    Ok(status)
+}
+
+
 #[repr(C, packed)]
 #[derive(Endian)]
 struct ElementStatusHeader {