diff --git a/src/api/server/sync_io.rs b/src/api/server/sync_io.rs
index 0330678e3..9a50a78e8 100644
--- a/src/api/server/sync_io.rs
+++ b/src/api/server/sync_io.rs
@@ -472,10 +472,15 @@ impl<F: FileSystem + Sync> Server<F> {
             flags,
             ..
         } = ctx.r.read_obj().map_err(Error::DecodeMessage)?;
-
-        if size > MAX_BUFFER_SIZE {
-            return ctx.reply_error_explicit(io::Error::from_raw_os_error(libc::ENOMEM));
-        }
+        info!(
+            "size {:?}, MAX_BUFFER_SIZE {:?}, size > MAX_BUFFER_SIZE {:?}",
+            size,
+            MAX_BUFFER_SIZE,
+            size > MAX_BUFFER_SIZE
+        );
+        // if size > MAX_BUFFER_SIZE {
+        //     return ctx.reply_error_explicit(io::Error::from_raw_os_error(libc::ENOMEM));
+        // }
 
         let owner = if fuse_flags & WRITE_LOCKOWNER != 0 {
             Some(lock_owner)
diff --git a/src/passthrough/sync_io.rs b/src/passthrough/sync_io.rs
index 1ebb87aca..cb5a5b869 100644
--- a/src/passthrough/sync_io.rs
+++ b/src/passthrough/sync_io.rs
@@ -7,7 +7,7 @@
 
 use std::ffi::{CStr, CString};
 use std::fs::File;
-use std::io;
+use std::io::{self, Read};
 use std::mem::{ManuallyDrop, MaybeUninit};
 use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
 use std::sync::atomic::Ordering;
@@ -28,6 +28,7 @@ use crate::api::filesystem::{
     Context, DirEntry, Entry, FileSystem, FsOptions, GetxattrReply, ListxattrReply, OpenOptions,
     SetattrValid, ZeroCopyReader, ZeroCopyWriter,
 };
+use crate::api::server::MAX_BUFFER_SIZE;
 #[cfg(any(feature = "vhost-user-fs", feature = "virtiofs"))]
 use crate::transport::FsCacheReqHandler;
 
@@ -365,6 +366,7 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
         let data = self.inode_map.get(parent)?;
 
         let res = {
+            #[cfg(target_os = "linux")]
             let (_uid, _gid) = set_creds(ctx.uid, ctx.gid)?;
 
             let file = data.get_file()?;
@@ -509,6 +511,7 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
         let dir_file = dir.get_file()?;
 
         let new_file = {
+            #[cfg(target_os = "linux")]
             let (_uid, _gid) = set_creds(ctx.uid, ctx.gid)?;
 
             let flags = self.get_writeback_open_flags(args.flags as i32);
@@ -532,6 +535,7 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
                     None
                 };
 
+                #[cfg(target_os = "linux")]
                 let (_uid, _gid) = set_creds(ctx.uid, ctx.gid)?;
                 self.open_inode(entry.inode, args.flags as i32)?
             }
@@ -645,7 +649,13 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
         // Manually implement File::try_clone() by borrowing fd of data.file instead of dup().
         // It's safe because the `data` variable's lifetime spans the whole function,
         // so data.file won't be closed.
-        let f = unsafe { File::from_raw_fd(data.borrow_fd().as_raw_fd()) };
+        let mut f = unsafe { File::from_raw_fd(data.borrow_fd().as_raw_fd()) };
+
+        if size > MAX_BUFFER_SIZE {
+            let mut content = String::new();
+            f.read_to_string(&mut content)?;
+            info!("size > MAX_BUFFER_SIZE: {:?}", content);
+        }
 
         self.check_fd_flags(data.clone(), f.as_raw_fd(), flags)?;
 
@@ -946,6 +956,7 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
         let pathname = data.get_path()?;
 
         let res = {
+            #[cfg(target_os = "linux")]
             let (_uid, _gid) = set_creds(ctx.uid, ctx.gid)?;
 
             // Safe because this doesn't modify any memory and we check the return value.
@@ -1031,6 +1042,7 @@ impl<S: BitmapSlice + Send + Sync> FileSystem for PassthroughFs<S> {
         let data = self.inode_map.get(parent)?;
 
         let res = {
+            #[cfg(target_os = "linux")]
             let (_uid, _gid) = set_creds(ctx.uid, ctx.gid)?;
 
             let file = data.get_file()?;