[pbs-devel] [PATCH proxmox-backup] tape: media_catalog: replace deprecated flock() with Flock

[Hannes Laimer]

nix 0.28.0 deprecated fcntl::flock() in favor of fcntl::Flock.
In commit() lock a cloned fd to avoid moving self.file

No functional change intended. Fixes deprecation warnings.

Signed-off-by: Hannes Laimer <h.laimer at proxmox.com>
---
 src/tape/media_catalog.rs | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/tape/media_catalog.rs b/src/tape/media_catalog.rs
index 63329a65..7307ca0f 100644
--- a/src/tape/media_catalog.rs
+++ b/src/tape/media_catalog.rs
@@ -9,6 +9,7 @@ use endian_trait::Endian;
 
 use proxmox_sys::fs::read_subdir;
 
+use nix::fcntl;
 use proxmox_io::{ReadExt, WriteExt};
 use proxmox_sys::fs::{create_path, fchown, CreateOptions};
 use proxmox_uuid::Uuid;
@@ -194,7 +195,7 @@ impl MediaCatalog {
         let me = proxmox_lang::try_block!({
             Self::create_basedir(base_path)?;
 
-            let mut file = std::fs::OpenOptions::new()
+            let file = std::fs::OpenOptions::new()
                 .read(true)
                 .write(write)
                 .create(create)
@@ -219,9 +220,12 @@ impl MediaCatalog {
             };
 
             // Note: lock file, to get a consistent view with load_catalog
-            nix::fcntl::flock(file.as_raw_fd(), nix::fcntl::FlockArg::LockExclusive)?;
-            let result = me.load_catalog(&mut file, media_id.media_set_label.as_ref());
-            nix::fcntl::flock(file.as_raw_fd(), nix::fcntl::FlockArg::Unlock)?;
+            let mut locked = fcntl::Flock::lock(file, nix::fcntl::FlockArg::LockExclusive)
+                .map_err(|(_, e)| format_err!("flock failed - {}", e))?;
+            let result = me.load_catalog(&mut locked, media_id.media_set_label.as_ref());
+            let file = locked
+                .unlock()
+                .map_err(|(_, e)| format_err!("flock unlock failed - {}", e))?;
 
             let (found_magic_number, _) = result?;
 
@@ -371,14 +375,19 @@ impl MediaCatalog {
             Some(ref mut file) => {
                 let pending = &self.pending;
                 // Note: lock file, to get a consistent view with load_catalog
-                nix::fcntl::flock(file.as_raw_fd(), nix::fcntl::FlockArg::LockExclusive)?;
+                let file_clone = file.try_clone()?;
+                let mut locked =
+                    fcntl::Flock::lock(file_clone, nix::fcntl::FlockArg::LockExclusive)
+                        .map_err(|(_, e)| format_err!("flock failed - {}", e))?;
                 let result: Result<(), Error> = proxmox_lang::try_block!({
-                    file.write_all(pending)?;
-                    file.flush()?;
-                    file.sync_data()?;
+                    locked.write_all(pending)?;
+                    locked.flush()?;
+                    locked.sync_data()?;
                     Ok(())
                 });
-                nix::fcntl::flock(file.as_raw_fd(), nix::fcntl::FlockArg::Unlock)?;
+                let _ = locked
+                    .unlock()
+                    .map_err(|(_, e)| format_err!("flock unlock failed - {}", e))?;
 
                 result?;
             }
-- 
2.47.3