tape: backup media catalogs

src/tape/file_formats/catalog_archive.rs

@@ -0,0 +1,89 @@
+use std::fs::File;
+use std::io::Read;
+
+use proxmox::{
+    sys::error::SysError,
+    tools::Uuid,
+};
+
+use crate::{
+    tape::{
+        TapeWrite,
+        file_formats::{
+            PROXMOX_TAPE_BLOCK_SIZE,
+            PROXMOX_BACKUP_CATALOG_ARCHIVE_MAGIC_1_0,
+            MediaContentHeader,
+            CatalogArchiveHeader,
+        },
+    },
+};
+
+/// Write a media catalog to the tape
+///
+/// Returns `Ok(Some(content_uuid))` on success, and `Ok(None)` if
+/// `LEOM` was detected before all data was written. The stream is
+/// marked inclomplete in that case and does not contain all data (The
+/// backup task must rewrite the whole file on the next media).
+///
+pub fn tape_write_catalog<'a>(
+    writer: &mut (dyn TapeWrite + 'a),
+    uuid: &Uuid,
+    media_set_uuid: &Uuid,
+    seq_nr: usize,
+    file: &mut File,
+) -> Result<Option<Uuid>, std::io::Error> {
+
+    let archive_header = CatalogArchiveHeader {
+        uuid: uuid.clone(),
+        media_set_uuid: media_set_uuid.clone(),
+        seq_nr: seq_nr as u64,
+    };
+
+    let header_data = serde_json::to_string_pretty(&archive_header)?.as_bytes().to_vec();
+
+    let header = MediaContentHeader::new(
+        PROXMOX_BACKUP_CATALOG_ARCHIVE_MAGIC_1_0, header_data.len() as u32);
+    let content_uuid: Uuid = header.uuid.into();
+
+    let leom = writer.write_header(&header, &header_data)?;
+    if leom {
+        writer.finish(true)?; // mark as incomplete
+        return Ok(None);
+    }
+
+    let mut file_copy_buffer = proxmox::tools::vec::undefined(PROXMOX_TAPE_BLOCK_SIZE);
+
+    let result: Result<(), std::io::Error> = proxmox::try_block!({
+
+        let file_size = file.metadata()?.len();
+        let mut remaining = file_size;
+
+        while remaining != 0 {
+            let got = file.read(&mut file_copy_buffer[..])?;
+            if got as u64 > remaining {
+                proxmox::io_bail!("catalog '{}' changed while reading", uuid);
+            }
+            writer.write_all(&file_copy_buffer[..got])?;
+            remaining -= got as u64;
+        }
+        if remaining > 0 {
+            proxmox::io_bail!("catalog '{}' shrunk while reading", uuid);
+        }
+        Ok(())
+    });
+    
+    match result {
+        Ok(()) => {
+            writer.finish(false)?;
+            Ok(Some(content_uuid))
+        }
+        Err(err) => {
+            if err.is_errno(nix::errno::Errno::ENOSPC) && writer.logical_end_of_media() {
+                writer.finish(true)?; // mark as incomplete
+                Ok(None)
+            } else {
+                Err(err)
+            }
+        }
+    }
+}

src/tape/file_formats/mod.rs

@@ -13,6 +13,9 @@ pub use chunk_archive::*;
 mod snapshot_archive;
 pub use snapshot_archive::*;
 
+mod catalog_archive;
+pub use catalog_archive::*;
+
 mod multi_volume_writer;
 pub use multi_volume_writer::*;