Support read on the client side

olivefs/src/filesystem.rs

@@ -11,13 +11,13 @@ use std::future::Future;
 
 use crate::Requester;
 use anyhow::{anyhow, Context};
+use fuser::consts::FOPEN_DIRECT_IO;
 use olivefs_common::error_codes::ENOENT;
 use olivefs_common::messages::{DataResponse, DirectoryEntry, OpenMode, VnodeId};
 use std::os::raw::c_int;
 use std::path::Path;
 use std::sync::Arc;
 use std::time::{Duration, SystemTime};
-use fuser::consts::FOPEN_DIRECT_IO;
 use tokio::sync::RwLock;
 
 pub mod encryption;
@@ -380,37 +380,40 @@ impl Filesystem for OliveFilesystem {
     fn read(
         &mut self,
         _req: &Request<'_>,
-        ino: u64,
+        _ino: u64,
         fh: u64,
         offset: i64,
         size: u32,
-        flags: i32,
-        lock_owner: Option<u64>,
+        _flags: i32,
+        _lock_owner: Option<u64>,
         reply: ReplyData,
     ) {
-        warn!(
-            "[Not Implemented] read(ino: {:#x?}, fh: {}, offset: {}, size: {}, \
-            flags: {:#x?}, lock_owner: {:?})",
-            ino, fh, offset, size, flags, lock_owner
+        // If you don't open files in direct I/O, the kernel caches things and uses the length from
+        // getattr — but potentially we want to allow the size to change on the server
+        // and not fall over, so we have to use direct I/O mode.
+
+        let requester = self.requester.clone();
+        let file_handle: u32 = fh.try_into().unwrap();
+
+        self.spawn_with_error_handler(
+            async move {
+                match requester.read(file_handle, offset, size).await? {
+                    DataResponse::Success(data) => {
+                        reply.data(&data);
+                    }
+                    DataResponse::Error { code, message } => {
+                        warn!(
+                            "read(fn: {:#x?}, offset: {:?}, size: {:?}) failed: {:?}",
+                            file_handle, offset, size, message
+                        );
+                        reply.error(code as c_int);
+                    }
+                }
+
+                Ok(())
+            },
+            "read",
         );
-
-        // TODO There seems to be a bug here, but it only seems to occur on the first read of a file
-        //      but oddly not after restarting olivefs....
-        // reply.data(&[42]);
-
-        // TODO searching online, it seems like making files get opened in direct I/O mode is the
-        //      probable solution. Otherwise the kernel caches things and uses the length from
-        //      getattr — but potentially we want to allow the size to change on the server
-        //      and not fall over?
-
-        if offset == 0 {
-            reply.data(&[42]);
-        } else {
-            reply.data(&[]);
-        }
-
-
-        //reply.error(ENOSYS);
     }
 
     /// Write data.

olivefs/src/requester.rs

@@ -197,4 +197,19 @@ impl Requester {
             .command(&DataCommand::ReleaseFile { file_handle })
             .await
     }
+
+    pub async fn read(
+        &self,
+        file_handle: u32,
+        offset: i64,
+        size: u32,
+    ) -> anyhow::Result<DataResponse<Vec<u8>>> {
+        self.internal
+            .command(&DataCommand::ReadFile {
+                file_handle,
+                offset,
+                size,
+            })
+            .await
+    }
 }

olivefs_common/src/messages.rs

@@ -45,6 +45,7 @@ pub enum DataCommand {
     Lookup { dir_vnode: VnodeId, name: String },
     OpenFile { vnode: VnodeId, mode: OpenMode },
     ReleaseFile { file_handle: u32 },
+    ReadFile { file_handle: u32, offset: i64, size: u32 },
 }
 
 pub trait DataResponseBase: Serialize + DeserializeOwned + Debug + Clone + 'static {}