fuse: Ensure readdir returns same ino as lookup

The filesystem test utility xfs-tests[1] failed on test generic/637 with
the error entry 8 has inode 72057594038044051, expected 112052
The expected inode returned from readdir is neither converted nor
the same inode as assigned by do_lookup, as stated in the docs
for DirEntry.ino.

Update readdir to perform do_lookup to get the correct inode number
and then convert this inode number to the expected format.

After this change the test generic/637 passes and no regressions in
other tests.

[1] https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/tree/

Signed-off-by: Champ-Goblem <[email protected]>

Author: Champ-Goblem

src/api/vfs/sync_io.rs

@@ -544,7 +544,18 @@ impl FileSystem for Vfs {
                 )
             }
 
-            (Right(fs), idata) => fs.readdir(ctx, idata.ino(), handle, size, offset, add_entry),
+            (Right(fs), idata) => fs.readdir(
+                ctx,
+                idata.ino(),
+                handle,
+                size,
+                offset,
+                &mut |mut dir_entry| {
+                    let new_ino = self.convert_inode(idata.fs_idx(), dir_entry.ino)?;
+                    dir_entry.ino = new_ino;
+                    add_entry(dir_entry)
+                },
+            ),
         }
     }
 

src/passthrough/sync_io.rs

@@ -436,7 +436,7 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
         if self.no_readdir.load(Ordering::Relaxed) {
             return Ok(());
         }
-        self.do_readdir(inode, handle, size, offset, &mut |mut dir_entry, dir| {
+        self.do_readdir(inode, handle, size, offset, &mut |mut dir_entry, _dir| {
             dir_entry.ino = {
                 // Safe because do_readdir() has ensured dir_entry.name is a
                 // valid [u8] generated by CStr::to_bytes().
@@ -447,8 +447,10 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
                     ))
                 };
 
-                let st = Self::stat(&dir, Some(name))?;
-                st.st_ino
+                let entry = self.do_lookup(inode, name)?;
+                let mut inodes = self.inode_map.get_map_mut();
+                self.forget_one(&mut inodes, entry.inode, 1);
+                entry.inode
             };
 
             add_entry(dir_entry)