1 files changed, 62 insertions, 3 deletions

diff --git a/src/fs.zig b/src/fs.zig
index 2a5102f4..db07672e 100644
--- a/src/fs.zig
+++ b/src/fs.zig
@@ -85,6 +85,14 @@ pub const WriteError = error{
     NoSpaceLeft,
     OpenFailed,
     WriteFailed,
+    // The rest are open(2)'s errno, named so errorWords says them.
+    NoSuchFileOrDirectory,
+    NotDir,
+    InvalidArgument,
+    FileBusy,
+    SymLinkLoop,
+    NoSuchDeviceOrAddress,
+    FileTooBig,
 };
 
 /// The host takes the bytes. The caller has given the turn up (`write`),
@@ -102,6 +110,13 @@ pub fn writeFile(path: []const u8, bytes: []const u8) WriteError!void {
         .ROFS => error.ReadOnlyFilesystem,
         .NOSPC, .DQUOT => error.NoSpaceLeft,
         .NAMETOOLONG => error.PathTooLong,
+        .NOENT => error.NoSuchFileOrDirectory,
+        .NOTDIR => error.NotDir,
+        .INVAL => error.InvalidArgument,
+        .BUSY, .TXTBSY => error.FileBusy,
+        .LOOP => error.SymLinkLoop,
+        .NXIO, .NODEV => error.NoSuchDeviceOrAddress,
+        .FBIG => error.FileTooBig,
         else => error.OpenFailed,
     };
     var off: usize = 0;
@@ -1554,6 +1569,36 @@ fn readFileLimit(gpa: std.mem.Allocator, path: []const u8, limit: usize) ![]u8 {
     return buf;
 }
 
+/// A 9P write of an Edit held while its commands run (Namespace.edit_hold).
+pub const EditHold = struct {
+    /// The listener's: the connection that asked, and its park.
+    asker: *anyopaque,
+    slot: u16,
+    seq: u64,
+    tag: u64,
+    node: u64,
+    handle: u32,
+    written: u32,
+    /// The Edit is done: applied, or failed with `said`.
+    done: bool = false,
+    errno: u16 = 0,
+    said: [256]u8 = undefined,
+    said_len: u16 = 0,
+
+    pub fn names(h: *const EditHold, req: tree.Req) bool {
+        return req.op == .write and req.tag == h.tag and req.node == h.node and req.handle == h.handle;
+    }
+
+    /// Its answer, the held record let go: the words copied out first.
+    pub fn answer(ns: *Namespace) tree.Reply {
+        const h = ns.edit_hold.?;
+        ns.edit_hold = null;
+        if (h.errno == 0) return .{ .tag = h.tag, .written = h.written };
+        @memcpy(ns.edit_said[0..h.said_len], h.said[0..h.said_len]);
+        return tree.failText(h.tag, h.errno, ns.edit_said[0..h.said_len]);
+    }
+};
+
 pub const Namespace = struct {
     socket_path: []const u8 = "",
     tcp_address: ?std.Io.net.IpAddress = null,
@@ -1613,9 +1658,15 @@ pub const Namespace = struct {
     /// A 9P write asked a language server something: the answer count it
     /// waits to change (`turn.lsp_answers`), so its failure is the write's.
     lsp_answer_at: ?u64 = null,
-    /// A write ran an Edit whose `<`, `|` or `>` commands are running: it is
-    /// answered once `turn.edit_answers` passes this, the Edit done.
-    edit_answer_at: ?u64 = null,
+    /// The request being served started an Edit whose `<`, `|` or `>`
+    /// commands run off the loop (edit_cmd.zig): the listener holds it.
+    edit_started: bool = false,
+    /// That write, held: answered once `done` (9p_io answerHeld), or
+    /// asked again by a retry of its park (Pardes.serveFs); a flush or a
+    /// hang-up stops the Edit (9p_io watchEdit).
+    edit_hold: ?EditHold = null,
+    /// The words a held Edit write was refused with, kept for its answer.
+    edit_said: [256]u8 = undefined,
     /// The pane a language answer filled (a Rename's preview): what the
     /// waiting 9P write answers once it is in (9p_io).
     lsp_result: ?u32 = null,
@@ -1757,3 +1808,11 @@ test {
 test "the tree's README lists src/ only when the build serves it" {
     try std.testing.expectEqual(limits.embedded_sources, std.mem.indexOf(u8, help, "src/") != null);
 }
+
+test "a write open(2) refuses says its errno in words" {
+    if (comptime @import("builtin").os.tag != .linux or !pardes.hosted) return error.SkipZigTest;
+    // /proc takes no new file: ENOENT, which used to read "open failed".
+    try std.testing.expectError(error.NoSuchFileOrDirectory, writeFile("/proc/pardes-no-such-file", "x"));
+    var words: [128]u8 = undefined;
+    try std.testing.expectEqualStrings("no such file or directory", pardes.Messages.errorWords(error.NoSuchFileOrDirectory, &words));
+}