text: #ifndef QEMU_9P_H
  #define QEMU_9P_H
  
  #include <dirent.h>
  #include <utime.h>
  #include <sys/resource.h>
  #include "fsdev/file-op-9p.h"
  #include "fsdev/9p-iov-marshal.h"
  #include "qemu/thread.h"
  #include "qemu/coroutine.h"
  
  enum {
      P9_TLERROR = 6,
      P9_RLERROR,
      P9_TSTATFS = 8,
      P9_RSTATFS,
      P9_TLOPEN = 12,
      P9_RLOPEN,
      P9_TLCREATE = 14,
      P9_RLCREATE,
      P9_TSYMLINK = 16,
      P9_RSYMLINK,
      P9_TMKNOD = 18,
      P9_RMKNOD,
      P9_TRENAME = 20,
      P9_RRENAME,
      P9_TREADLINK = 22,
      P9_RREADLINK,
      P9_TGETATTR = 24,
      P9_RGETATTR,
      P9_TSETATTR = 26,
      P9_RSETATTR,
      P9_TXATTRWALK = 30,
      P9_RXATTRWALK,
      P9_TXATTRCREATE = 32,
      P9_RXATTRCREATE,
      P9_TREADDIR = 40,
      P9_RREADDIR,
      P9_TFSYNC = 50,
      P9_RFSYNC,
      P9_TLOCK = 52,
      P9_RLOCK,
      P9_TGETLOCK = 54,
      P9_RGETLOCK,
      P9_TLINK = 70,
      P9_RLINK,
      P9_TMKDIR = 72,
      P9_RMKDIR,
      P9_TRENAMEAT = 74,
      P9_RRENAMEAT,
      P9_TUNLINKAT = 76,
      P9_RUNLINKAT,
      P9_TVERSION = 100,
      P9_RVERSION,
      P9_TAUTH = 102,
      P9_RAUTH,
      P9_TATTACH = 104,
      P9_RATTACH,
      P9_TERROR = 106,
      P9_RERROR,
      P9_TFLUSH = 108,
      P9_RFLUSH,
      P9_TWALK = 110,
      P9_RWALK,
      P9_TOPEN = 112,
      P9_ROPEN,
      P9_TCREATE = 114,
      P9_RCREATE,
      P9_TREAD = 116,
      P9_RREAD,
      P9_TWRITE = 118,
      P9_RWRITE,
      P9_TCLUNK = 120,
      P9_RCLUNK,
      P9_TREMOVE = 122,
      P9_RREMOVE,
      P9_TSTAT = 124,
      P9_RSTAT,
      P9_TWSTAT = 126,
      P9_RWSTAT,
  };
  
  
  /* qid.types */
  enum {
      P9_QTDIR = 0x80,
      P9_QTAPPEND = 0x40,
      P9_QTEXCL = 0x20,
      P9_QTMOUNT = 0x10,
      P9_QTAUTH = 0x08,
      P9_QTTMP = 0x04,
      P9_QTSYMLINK = 0x02,
      P9_QTLINK = 0x01,
      P9_QTFILE = 0x00,
  };
  
  enum p9_proto_version {
      V9FS_PROTO_2000U = 0x01,
      V9FS_PROTO_2000L = 0x02,
  };
  
  #define P9_NOTAG    UINT16_MAX
  #define P9_NOFID    UINT32_MAX
  #define P9_MAXWELEM 16
  
  #define FID_REFERENCED          0x1
  #define FID_NON_RECLAIMABLE     0x2
  static inline char *rpath(FsContext *ctx, const char *path)
  {
      return g_strdup_printf("%s/%s", ctx->fs_root, path);
  }
  
  /*
   * ample room for Twrite/Rread header
   * size[4] Tread/Twrite tag[2] fid[4] offset[8] count[4]
   */
  #define P9_IOHDRSZ 24
  
  typedef struct V9fsPDU V9fsPDU;
  struct V9fsState;
  
  struct V9fsPDU
  {
      uint32_t size;
      uint16_t tag;
      uint8_t id;
      uint8_t cancelled;
      CoQueue complete;
      struct V9fsState *s;
      QLIST_ENTRY(V9fsPDU) next;
      uint32_t idx;
  };
  
  
  /* FIXME
   * 1) change user needs to set groups and stuff
   */
  
  #define MAX_REQ         128
  #define MAX_TAG_LEN     32
  
  #define BUG_ON(cond) assert(!(cond))
  
  typedef struct V9fsFidState V9fsFidState;
  
  enum {
      P9_FID_NONE = 0,
      P9_FID_FILE,
      P9_FID_DIR,
      P9_FID_XATTR,
  };
  
  typedef struct V9fsConf
  {
      /* tag name for the device */
      char *tag;
      char *fsdev_id;
  } V9fsConf;
  
  typedef struct V9fsXattr
  {
      uint64_t copied_len;
      uint64_t len;
      void *value;
      V9fsString name;
      int flags;
      bool xattrwalk_fid;
  } V9fsXattr;
  
  typedef struct V9fsDir {
      DIR *stream;
      QemuMutex readdir_mutex;
  } V9fsDir;
  
  static inline void v9fs_readdir_lock(V9fsDir *dir)
  {
      qemu_mutex_lock(&dir->readdir_mutex);
  }
  
  static inline void v9fs_readdir_unlock(V9fsDir *dir)
  {
      qemu_mutex_unlock(&dir->readdir_mutex);
  }
  
  static inline void v9fs_readdir_init(V9fsDir *dir)
  {
      qemu_mutex_init(&dir->readdir_mutex);
  }
  
  /*
   * Filled by fs driver on open and other
   * calls.
   */
  union V9fsFidOpenState {
      int fd;
      V9fsDir dir;
      V9fsXattr xattr;
      /*
       * private pointer for fs drivers, that
       * have its own internal representation of
       * open files.
       */
      void *private;
  };
  
  struct V9fsFidState
  {
      int fid_type;
      int32_t fid;
      V9fsPath path;
      V9fsFidOpenState fs;
      V9fsFidOpenState fs_reclaim;
      int flags;
      int open_flags;
      uid_t uid;
      int ref;
      int clunked;
      V9fsFidState *next;
      V9fsFidState *rclm_lst;
  };
  
  typedef struct V9fsState
  {
      QLIST_HEAD(, V9fsPDU) free_list;
      QLIST_HEAD(, V9fsPDU) active_list;
      V9fsFidState *fid_list;
      FileOperations *ops;
      FsContext ctx;
      char *tag;
      enum p9_proto_version proto_version;
      int32_t msize;
      V9fsPDU pdus[MAX_REQ];
      const struct V9fsTransport *transport;
      /*
       * lock ensuring atomic path update
       * on rename.
       */
      CoRwlock rename_lock;
      int32_t root_fid;
      Error *migration_blocker;
      V9fsConf fsconf;
      V9fsQID root_qid;
  } V9fsState;
  
  /* 9p2000.L open flags */
  #define P9_DOTL_RDONLY        00000000
  #define P9_DOTL_WRONLY        00000001
  #define P9_DOTL_RDWR          00000002
  #define P9_DOTL_NOACCESS      00000003
  #define P9_DOTL_CREATE        00000100
  #define P9_DOTL_EXCL          00000200
  #define P9_DOTL_NOCTTY        00000400
  #define P9_DOTL_TRUNC         00001000
  #define P9_DOTL_APPEND        00002000
  #define P9_DOTL_NONBLOCK      00004000
  #define P9_DOTL_DSYNC         00010000
  #define P9_DOTL_FASYNC        00020000
  #define P9_DOTL_DIRECT        00040000
  #define P9_DOTL_LARGEFILE     00100000
  #define P9_DOTL_DIRECTORY     00200000
  #define P9_DOTL_NOFOLLOW      00400000
  #define P9_DOTL_NOATIME       01000000
  #define P9_DOTL_CLOEXEC       02000000
  #define P9_DOTL_SYNC          04000000
  
  /* 9p2000.L at flags */
  #define P9_DOTL_AT_REMOVEDIR         0x200
  
  /* 9P2000.L lock type */
  #define P9_LOCK_TYPE_RDLCK 0
  #define P9_LOCK_TYPE_WRLCK 1
  #define P9_LOCK_TYPE_UNLCK 2
  
  #define P9_LOCK_SUCCESS 0
  #define P9_LOCK_BLOCKED 1
  #define P9_LOCK_ERROR 2
  #define P9_LOCK_GRACE 3
  
  #define P9_LOCK_FLAGS_BLOCK 1
  #define P9_LOCK_FLAGS_RECLAIM 2
  
  typedef struct V9fsFlock
  {
      uint8_t type;
      uint32_t flags;
      uint64_t start; /* absolute offset */
      uint64_t length;
      uint32_t proc_id;
      V9fsString client_id;
  } V9fsFlock;
  
  typedef struct V9fsGetlock
  {
      uint8_t type;
      uint64_t start; /* absolute offset */
      uint64_t length;
      uint32_t proc_id;
      V9fsString client_id;
  } V9fsGetlock;
  
  extern int open_fd_hw;
  extern int total_open_fd;
  
  static inline void v9fs_path_write_lock(V9fsState *s)
  {
      if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
          qemu_co_rwlock_wrlock(&s->rename_lock);
      }
  }
  
  static inline void v9fs_path_read_lock(V9fsState *s)
  {
      if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
          qemu_co_rwlock_rdlock(&s->rename_lock);
      }
  }
  
  static inline void v9fs_path_unlock(V9fsState *s)
  {
      if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
          qemu_co_rwlock_unlock(&s->rename_lock);
      }
  }
  
  static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
  {
      return pdu->cancelled;
  }
  
  void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
  void v9fs_path_init(V9fsPath *path);
  void v9fs_path_free(V9fsPath *path);
  void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
  void v9fs_path_copy(V9fsPath *lhs, V9fsPath *rhs);
  int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
                        const char *name, V9fsPath *path);
  int v9fs_device_realize_common(V9fsState *s, Error **errp);
  void v9fs_device_unrealize_common(V9fsState *s, Error **errp);
  
  ssize_t pdu_marshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...);
  ssize_t pdu_unmarshal(V9fsPDU *pdu, size_t offset, const char *fmt, ...);
  V9fsPDU *pdu_alloc(V9fsState *s);
  void pdu_free(V9fsPDU *pdu);
  void pdu_submit(V9fsPDU *pdu);
  void v9fs_reset(V9fsState *s);
  
  struct V9fsTransport {
      ssize_t     (*pdu_vmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
                                  va_list ap);
      ssize_t     (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
                                    va_list ap);
      void        (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
                                          unsigned int *pniov, size_t size);
      void        (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
                                           unsigned int *pniov);
      void        (*push_and_notify)(V9fsPDU *pdu);
  };
  
  static inline int v9fs_register_transport(V9fsState *s,
          const struct V9fsTransport *t)
  {
      assert(!s->transport);
      s->transport = t;
      return 0;
  }
  
  #endif
  