1 files changed, 17 insertions, 1 deletions

diff --git a/src/9p.zig b/src/9p.zig
index 9513fdb5..2948b9ed 100644
--- a/src/9p.zig
+++ b/src/9p.zig
@@ -511,7 +511,11 @@ pub fn Server(comptime fs: type, comptime fid_capacity: usize) type {
             if (st.type != std.math.maxInt(u16) or st.dev != std.math.maxInt(u32) or
                 st.qid.type != std.math.maxInt(u8) or st.qid.version != std.math.maxInt(u32) or
                 st.qid.path != std.math.maxInt(u64) or st.mode != std.math.maxInt(u32) or
-                st.atime != std.math.maxInt(u32) or st.mtime != std.math.maxInt(u32) or
+                st.atime != std.math.maxInt(u32) or
+                // Linux v9fs follows O_TRUNC with Twstat(length=0, mtime=now).
+                // Accept that timestamp hint with truncation; this control
+                // filesystem does not persist caller-selected timestamps.
+                (st.mtime != std.math.maxInt(u32) and st.length != 0) or
                 st.name.len != 0 or st.uid.len != 0 or st.gid.len != 0 or st.muid.len != 0)
                 return s.fail(tag, e_wstat);
             if (st.length == std.math.maxInt(u64)) {
@@ -738,6 +742,7 @@ pub fn Server(comptime fs: type, comptime fid_capacity: usize) type {
                         return;
                     }
                     const f = s.jobFid() orelse return;
+                    if (r.attr.node != 0) f.node = r.attr.node;
                     f.open = true;
                     f.omode = j.omode;
                     f.handle = r.handle;
@@ -1729,6 +1734,7 @@ test "9p server: Twstat with a zero length is the truncate, and so is OTRUNC" {
     changes[11].muid = "writer";
     for (changes) |change| {
         for ([_]u64{ std.math.maxInt(u64), 0 }) |length| {
+            if (change.mtime != std.math.maxInt(u32) and length == 0) continue;
             var attributes = change;
             attributes.length = length;
             const calls = h.fsys.calls;
@@ -1741,6 +1747,16 @@ test "9p server: Twstat with a zero length is the truncate, and so is OTRUNC" {
         }
     }
 
+    // Captured Linux v9fs O_TRUNC follow-up: length=0 plus current mtime.
+    var linux_truncate = sentinel;
+    linux_truncate.length = 0;
+    linux_truncate.mtime = 1789432552;
+    try h.send(21, .{ .twstat = .{ .fid = 1, .stat = linux_truncate } });
+    got = try h.reap();
+    try testing.expect(got.msg == .rwstat);
+    try testing.expectEqualStrings("", h.fsys.body);
+    h.fsys.body = "hello, body\n";
+
     var zero = sentinel;
     zero.length = 0;
     try h.send(9, .{ .twstat = .{ .fid = 1, .stat = zero } });