From 4458fee20e24b48cac18c1b5936e8e0bdce24fb5 Mon Sep 17 00:00:00 2001
From: Firelight Flagboy <firelight.flagboy@gmail.com>
Date: Wed, 27 Nov 2024 16:17:54 +0100
Subject: [PATCH] Fix cache concurrency issue

Using the same cache key across multiple jobs can cause issues if we make assumption about it's content (like installing tools if not hit on the cache).
---
 .github/workflows/ci.yml |  4 +-
 macos-rename-issue.md    | 95 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+), 2 deletions(-)
 create mode 100644 macos-rename-issue.md

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc1c38ee..55b9308f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -27,7 +27,7 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml', '.github/workflows/*.yml') }}
+          key: ${{ runner.os }}-cargo-compile-${{ matrix.libfuse }}-${{ matrix.features }}-${{ hashFiles('**/Cargo.toml', '.github/workflows/*.yml') }}
 
       - name: Install packages
         run: |
@@ -61,7 +61,7 @@ jobs:
             ~/.cargo/registry/cache/
             ~/.cargo/git/db/
             target/
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.toml', '.github/workflows/*.yml') }}
+          key: ${{ runner.os }}-cargo-ci-${{ hashFiles('**/Cargo.toml', '.github/workflows/*.yml') }}
 
       - name: Install packages
         run: |
diff --git a/macos-rename-issue.md b/macos-rename-issue.md
new file mode 100644
index 00000000..c47fd4f2
--- /dev/null
+++ b/macos-rename-issue.md
@@ -0,0 +1,95 @@
+# MacOS Rename Issue
+
+I've create a MemFS with `fuser` and I'm having issue with the rename operation on MacOS (using MacFuse@4.8) where the rename request is provided with empty filenames:
+
+```shell
+touch bar
+mv bar zar
+```
+
+Result in the following Request log:
+
+```txt
+FUSE(  4) ino 0x00..01 RENAME src FilenameDir { dir: Inode(1), name: "" }, dest FilenameDir { dir: Inode(1), name: "" }
+```
+
+I've added a log that dump the content of `data` before it's decoded into the Rename Request:
+
+```txt
+Parsing opcode FUSE_RENAME, data: AQAAAAAAAAAAAAAAAAAAAGJhcgB6YXIA
+```
+
+By decoding the data, we get:
+
+```shell
+$ echo AQAAAAAAAAAAAAAAAAAAAGJhcgB6YXIA | base64 --decode | xxd
+00000000: 0100 0000 0000 0000 0000 0000 0000 0000  ................
+00000010: 6261 7200 7a61 7200                      bar.zar.
+```
+
+So we have the filenames that are provided, that mean the issue is during the parsing of the low-level request from macFuse.
+`fuser` define the Rename request like so:
+
+```rust
+#[derive(Debug)]
+pub struct Rename<'a> {
+    header: &'a fuse_in_header,
+    arg: &'a fuse_rename_in,
+    name: &'a Path,
+    newname: &'a Path,
+}
+```
+
+> [`Rename`](https://github.com/cberner/fuser/blob/424bbcaa30a586a6dc99b5019f5e9b9f7755a31f/src/ll/request.rs#L581-L587)
+
+```rust
+#[repr(C)]
+#[derive(Debug, FromBytes, FromZeroes)]
+pub struct fuse_rename_in {
+    pub newdir: u64,
+}
+```
+
+> [`fuse_rename_in`](https://github.com/cberner/fuser/blob/v0.14.0/src/ll/fuse_abi.rs#L584-L588)
+
+Parsing the provided data by MacFuse result in:
+
+```rst
++---------------------+------------+---------------+------------------------------------+
+| Rename                                                                                |
++=====================+============+===============+====================================+
+| fuse_rename_in      |                                                                 |
++---------------------+------------+---------------+------------------------------------+
+| newdir: u64         | name: Path | newname: Path | _unused_                           |
++---------------------+------------+---------------+------------------------------------+
+| 0100 0000 0000 0000 | 00         | 00            | 0000 0000 0000 6261 7200 7a61 7200 |
++---------------------+------------+---------------+------------------------------------+
+```
+
+`fuse_rename_in` is defined as the following on MacFuse:
+
+```c
+struct fuse_rename_in {
+	__u64	newdir;
+#ifdef __APPLE__
+	__u32	flags;
+	__u32	padding;
+#endif
+};
+```
+
+> [`fuse_rename_in`](https://github.com/osxfuse/fuse/blob/6f7322893456f6ff9db145f096b9bfc2ba95d627/include/fuse_kernel.h#L446-L452)
+
+If we map the data received, everything seems to _click into place_:
+
+```rst
++---------------------+------------+--------------+------------+---------------+
+| Rename                                                                       |
++=====================+============+==============+============+===============+
+| fuse_rename_in                                  |                            |
++---------------------+------------+--------------+------------+---------------+
+| newdir: u64         | flags: u32 | padding: u32 | name: Path | newname: Path |
++---------------------+------------+--------------+------------+---------------+
+| 0100 0000 0000 0000 | 0000 0000  | 0000 0000    | 6261 7200  | 7a61 7200     |
++---------------------+------------+--------------+------------+---------------+
+```