Watdfs P2

Build and run

cd /u5/y3739zhang/cs454/p2
make clean && make all   # builds libwatdfs.a watdfs_server watdfs_client

Server (blocking; prints address/port then serves):

mkdir -p /tmp/$USER/p2_server
./watdfs_server /tmp/$USER/p2_server   # stdout: export SERVER_ADDRESS=... export SERVER_PORT=...

Client (needs env from server):

export SERVER_ADDRESS=<from server>
export SERVER_PORT=<from server>
./watdfs_client -f <mount_point> <path_to_cache> <cache_interval>

RPC argument pattern

• Client: Allocate void **args, int arg_types[N+1]. Set types with (1u << ARG_INPUT)|(1u << ARG_ARRAY)|(ARG_CHAR << 16u)| length, etc. Last arg_types[N] = 0. Call rpcCall("name", arg_types, args). Check rpc_ret < 0 and server retcode; return retcode or -EINVAL. Free buffers.
• Server: Cast args[i] to path, structs, int *ret. Use get_full_path(short_path) for path-based calls; free(full_path) after. Set *ret = 0 or *ret = -errno. Return 0 from handler.

A1 baseline (already in place)

• Client: init/destroy (rpcClientInit/rpcClientDestroy), getattr, mknod, open, release, read (chunked by MAX_ARRAY_LEN), write (chunked), truncate, fsync, utimensat.
• Server: getattr (stat), mknod, open (fd in fi->fh), release (close), read (pread), write (pwrite), truncate, fsync, utimensat; all RPCs registered in main.

P2/P3 additions (spec-driven)

• P2: Implement any extra FUSE ops or caching per P1–P2 Spec (e.g. path_to_cache, cache_interval in init; cache in client).
• A3: Add rw_lock.cpp/rw_lock.h to server Makefile; use reader–writer locks for shared server state (e.g. around global or per-file state).

Conventions

• Server: no stdout before rpcServerInit(); use DLOG for debug; zero stat on client when returning negative ret. Read/write in chunks ≤ MAX_ARRAY_LEN. Do not modify rpc.h.