1 files changed, 108 insertions, 0 deletions
diff --git a/src/commands/debug/mod.rs b/src/commands/debug/mod.rs
new file mode 100644
index 00000000..e5651921
--- /dev/null
+++ b/src/commands/debug/mod.rs
@@ -0,0 +1,108 @@
+use clap::Parser;
+use std::ffi::{c_char, CString};
+use std::io::{BufRead, Write};
+
+use bch_bindgen::bcachefs;
+use bch_bindgen::c;
+use bch_bindgen::fs::Fs;
+
+mod bkey_types;
+mod parser;
+
+use bch_bindgen::c::bpos;
+
+/// Debug a bcachefs filesystem.
+#[derive(Parser, Debug)]
+pub struct Cli {
+    #[arg(required(true))]
+    devices: Vec<std::path::PathBuf>,
+}
+
+#[derive(Debug)]
+enum DebugCommand {
+    Dump(DumpCommand),
+    Update(UpdateCommand),
+}
+
+#[derive(Debug)]
+struct DumpCommand {
+    btree: String,
+    bpos: bpos,
+}
+
+#[derive(Debug)]
+struct UpdateCommand {
+    btree: String,
+    bpos: bpos,
+    bkey: String,
+    field: String,
+    value: u64,
+}
+
+fn update(fs: &Fs, type_list: &bkey_types::BkeyTypes, cmd: UpdateCommand) {
+    let bkey = CString::new(cmd.bkey.clone()).unwrap();
+    let bkey = bkey.as_ptr() as *const c_char;
+
+    let id: bch_bindgen::c::btree_id = cmd.btree.parse().expect("no such btree");
+
+    if let Some((size, offset)) = type_list.get_member_layout(&cmd.bkey, &cmd.field) {
+        let update = c::bkey_update {
+            id,
+            bkey,
+            offset,
+            size,
+            value: cmd.value,
+        };
+        unsafe {
+            c::cmd_update_bkey(fs.raw, update, cmd.bpos);
+        }
+    } else {
+        println!("unknown field '{}'", cmd.field);
+    }
+}
+
+fn dump(fs: &Fs, cmd: DumpCommand) {
+    let id: bch_bindgen::c::btree_id = cmd.btree.parse().expect("no such btree");
+
+    unsafe {
+        c::cmd_dump_bkey(fs.raw, id, cmd.bpos);
+    }
+}
+
+pub fn debug(argv: Vec<String>) -> i32 {
+    fn prompt() {
+        print!("bcachefs> ");
+        std::io::stdout().flush().unwrap();
+    }
+
+    let opt = Cli::parse_from(argv);
+
+    let fs_opts: bcachefs::bch_opts = Default::default();
+    let fs = match Fs::open(&opt.devices, fs_opts) {
+        Ok(fs) => fs,
+        Err(_) => {
+            return 1;
+        }
+    };
+
+    let type_list = bkey_types::get_bkey_type_info();
+
+    prompt();
+    let stdin = std::io::stdin();
+    for line in stdin.lock().lines() {
+        let line = line.unwrap();
+        if let Some(cmd) = parser::parse_command(&line) {
+            match cmd {
+                // usage: dump <btree_type> <bpos>
+                DebugCommand::Dump(cmd) => dump(&fs, cmd),
+                // usage: update <btree_type> <bpos> <bkey_type>.<field>=<value>
+                DebugCommand::Update(cmd) => update(&fs, &type_list, cmd),
+            }
+        } else {
+            println!("failed to parse a command");
+        };
+        prompt();
+    }
+
+    0
+}