From 45cbd2d0db81625e1307a4b81ac5500251da40ad Mon Sep 17 00:00:00 2001
From: Olivier 'reivilibre <olivier@librepush.net>
Date: Thu, 20 Jan 2022 18:33:22 +0000
Subject: [PATCH] Theoretically support sending GetAttr commands to the server

---
 olivefs/Cargo.toml                            |  2 +-
 olivefs/src/filesystem.rs                     | 46 +++++++++++++++++--
 olivefs/src/requester.rs                      |  8 ++--
 olivefs_common/src/messages/messages_fuser.rs | 27 +++++++++--
 4 files changed, 71 insertions(+), 12 deletions(-)

diff --git a/olivefs/Cargo.toml b/olivefs/Cargo.toml
index e88bd76..5721ed2 100644
--- a/olivefs/Cargo.toml
+++ b/olivefs/Cargo.toml
@@ -36,4 +36,4 @@ fuser = "0.10.0"
 libc = "0.2.112"
 
 # Common
-olivefs_common = { path = "../olivefs_common" }
+olivefs_common = { path = "../olivefs_common", features = ["fuser"] }
diff --git a/olivefs/src/filesystem.rs b/olivefs/src/filesystem.rs
index d096156..77579f4 100644
--- a/olivefs/src/filesystem.rs
+++ b/olivefs/src/filesystem.rs
@@ -4,10 +4,13 @@ use fuser::{
     ReplyStatfs, ReplyWrite, ReplyXattr, Request, TimeOrNow,
 };
 use libc::{ENOSYS, EPERM};
-use log::{debug, warn};
+use log::{debug, error, warn};
 use std::ffi::OsStr;
+use std::future::Future;
 
 use crate::Requester;
+use anyhow::Context;
+use olivefs_common::messages::{DataResponse, VnodeId};
 use std::os::raw::c_int;
 use std::path::Path;
 use std::sync::Arc;
@@ -31,7 +34,7 @@ impl Filesystem for OliveFilesystem {
     /// Initialize filesystem.
     /// Called before any other filesystem method.
     /// The kernel module connection can be configured using the KernelConfig object
-    fn init(&mut self, req: &Request<'_>, _config: &mut KernelConfig) -> Result<(), c_int> {
+    fn init(&mut self, _req: &Request<'_>, _config: &mut KernelConfig) -> Result<(), c_int> {
         // TODO config has some interesting values.
         Ok(())
     }
@@ -92,8 +95,30 @@ impl Filesystem for OliveFilesystem {
 
     /// Get file attributes.
     fn getattr(&mut self, _req: &Request<'_>, ino: u64, reply: ReplyAttr) {
-        warn!("[Not Implemented] getattr(ino: {:#x?})", ino);
-        reply.error(ENOSYS);
+        let requester = self.requester.clone();
+
+        self.spawn_with_error_handler(
+            async move {
+                let vnode = VnodeId(
+                    ino.try_into()
+                        .context("Converting u64 inode to u32 VnodeId.")?,
+                );
+
+                match requester.getattr(vnode).await? {
+                    DataResponse::Success(file_metadata) => {
+                        let file_attr = file_metadata.into();
+                        reply.attr(&Duration::from_secs(5), &file_attr);
+                    }
+                    DataResponse::Error { code, message } => {
+                        warn!("getattr(ino: {:#x?}) failed: {:?}", ino, message);
+                        reply.error(code as c_int);
+                    }
+                }
+
+                Ok(())
+            },
+            "getattr",
+        );
     }
 
     /// Set file attributes.
@@ -729,3 +754,16 @@ impl Filesystem for OliveFilesystem {
         reply.error(ENOSYS);
     }
 }
+
+impl OliveFilesystem {
+    pub fn spawn_with_error_handler<Fut>(&self, future: Fut, name: &'static str)
+    where
+        Fut: Future<Output = anyhow::Result<()>> + Send + 'static,
+    {
+        self.tokio_runtime.spawn(async move {
+            if let Err(error) = future.await {
+                error!("Error in {}: {:?}", name, error);
+            }
+        });
+    }
+}
diff --git a/olivefs/src/requester.rs b/olivefs/src/requester.rs
index 80baa7f..5cf558e 100644
--- a/olivefs/src/requester.rs
+++ b/olivefs/src/requester.rs
@@ -12,7 +12,7 @@ use std::str::FromStr;
 use std::sync::Arc;
 
 use olivefs_common::io::read_file;
-use olivefs_common::messages::{DataCommand, DataResponse, VnodeId};
+use olivefs_common::messages::{DataCommand, DataResponse, FileMetadata, VnodeId};
 use olivefs_common::networking::{
     hello_handshake, read_bare_message, send_bare_message, ALPN_PROTOCOL,
 };
@@ -122,7 +122,7 @@ impl RequesterInternal {
     }
 
     pub async fn command<R: DeserializeOwned>(
-        &mut self,
+        &self,
         command: &DataCommand,
     ) -> anyhow::Result<DataResponse<R>> {
         self.with_stream(|mut tx, mut rx| async {
@@ -141,7 +141,7 @@ impl Requester {
         Requester { internal }
     }
 
-    pub async fn getattr(&mut self, _vnode: VnodeId) -> anyhow::Result<DataResponse<()>> {
-        todo!()
+    pub async fn getattr(&self, vnode: VnodeId) -> anyhow::Result<DataResponse<FileMetadata>> {
+        self.internal.command(&DataCommand::GetAttr { vnode }).await
     }
 }
diff --git a/olivefs_common/src/messages/messages_fuser.rs b/olivefs_common/src/messages/messages_fuser.rs
index 6a0a73e..a6361d3 100644
--- a/olivefs_common/src/messages/messages_fuser.rs
+++ b/olivefs_common/src/messages/messages_fuser.rs
@@ -1,6 +1,5 @@
-use crate::messages::FileKind;
-use fuser::FileType;
-use std::fs::FileType;
+use crate::messages::{FileKind, FileMetadata};
+use fuser::{FileAttr, FileType};
 
 impl From<FileType> for FileKind {
     fn from(filetype: FileType) -> Self {
@@ -29,3 +28,25 @@ impl Into<FileType> for FileKind {
         }
     }
 }
+
+impl Into<FileAttr> for FileMetadata {
+    fn into(self) -> FileAttr {
+        FileAttr {
+            ino: self.ino.0 as u64,
+            size: self.size,
+            blocks: self.blocks,
+            atime: self.atime,
+            mtime: self.mtime,
+            ctime: self.ctime,
+            crtime: self.ctime,
+            kind: self.kind.into(),
+            perm: self.perm,
+            nlink: self.nlink,
+            uid: self.uid,
+            gid: self.gid,
+            rdev: self.rdev,
+            blksize: self.blksize,
+            flags: 0,
+        }
+    }
+}