hw/9pfs/9p.h

   1 #ifndef QEMU_9P_H
   2 #define QEMU_9P_H
   3
   4 #include <dirent.h>
   5 #include <utime.h>
   6 #include <sys/resource.h>
   7 #include "fsdev/file-op-9p.h"
   8 #include "fsdev/9p-iov-marshal.h"
   9 #include "qemu/thread.h"
  10 #include "qemu/coroutine.h"
  11 #include "qemu/qht.h"
  12
  13 enum {
  14     P9_TLERROR = 6,
  15     P9_RLERROR,
  16     P9_TSTATFS = 8,
  17     P9_RSTATFS,
  18     P9_TLOPEN = 12,
  19     P9_RLOPEN,
  20     P9_TLCREATE = 14,
  21     P9_RLCREATE,
  22     P9_TSYMLINK = 16,
  23     P9_RSYMLINK,
  24     P9_TMKNOD = 18,
  25     P9_RMKNOD,
  26     P9_TRENAME = 20,
  27     P9_RRENAME,
  28     P9_TREADLINK = 22,
  29     P9_RREADLINK,
  30     P9_TGETATTR = 24,
  31     P9_RGETATTR,
  32     P9_TSETATTR = 26,
  33     P9_RSETATTR,
  34     P9_TXATTRWALK = 30,
  35     P9_RXATTRWALK,
  36     P9_TXATTRCREATE = 32,
  37     P9_RXATTRCREATE,
  38     P9_TREADDIR = 40,
  39     P9_RREADDIR,
  40     P9_TFSYNC = 50,
  41     P9_RFSYNC,
  42     P9_TLOCK = 52,
  43     P9_RLOCK,
  44     P9_TGETLOCK = 54,
  45     P9_RGETLOCK,
  46     P9_TLINK = 70,
  47     P9_RLINK,
  48     P9_TMKDIR = 72,
  49     P9_RMKDIR,
  50     P9_TRENAMEAT = 74,
  51     P9_RRENAMEAT,
  52     P9_TUNLINKAT = 76,
  53     P9_RUNLINKAT,
  54     P9_TVERSION = 100,
  55     P9_RVERSION,
  56     P9_TAUTH = 102,
  57     P9_RAUTH,
  58     P9_TATTACH = 104,
  59     P9_RATTACH,
  60     P9_TERROR = 106,
  61     P9_RERROR,
  62     P9_TFLUSH = 108,
  63     P9_RFLUSH,
  64     P9_TWALK = 110,
  65     P9_RWALK,
  66     P9_TOPEN = 112,
  67     P9_ROPEN,
  68     P9_TCREATE = 114,
  69     P9_RCREATE,
  70     P9_TREAD = 116,
  71     P9_RREAD,
  72     P9_TWRITE = 118,
  73     P9_RWRITE,
  74     P9_TCLUNK = 120,
  75     P9_RCLUNK,
  76     P9_TREMOVE = 122,
  77     P9_RREMOVE,
  78     P9_TSTAT = 124,
  79     P9_RSTAT,
  80     P9_TWSTAT = 126,
  81     P9_RWSTAT,
  82 };
  83
  84
  85 /* qid.types */
  86 enum {
  87     P9_QTDIR = 0x80,
  88     P9_QTAPPEND = 0x40,
  89     P9_QTEXCL = 0x20,
  90     P9_QTMOUNT = 0x10,
  91     P9_QTAUTH = 0x08,
  92     P9_QTTMP = 0x04,
  93     P9_QTSYMLINK = 0x02,
  94     P9_QTLINK = 0x01,
  95     P9_QTFILE = 0x00,
  96 };
  97
  98 typedef enum P9ProtoVersion {
  99     V9FS_PROTO_2000U = 0x01,
 100     V9FS_PROTO_2000L = 0x02,
 101 } P9ProtoVersion;
 102
 103 #define P9_NOTAG    UINT16_MAX
 104 #define P9_NOFID    UINT32_MAX
 105 #define P9_MAXWELEM 16
 106
 107 #define FID_REFERENCED          0x1
 108 #define FID_NON_RECLAIMABLE     0x2
 109 static inline char *rpath(FsContext *ctx, const char *path)
 110 {
 111     return g_strdup_printf("%s/%s", ctx->fs_root, path);
 112 }
 113
 114 /*
 115  * ample room for Twrite/Rread header
 116  * size[4] Tread/Twrite tag[2] fid[4] offset[8] count[4]
 117  */
 118 #define P9_IOHDRSZ 24
 119
 120 typedef struct V9fsPDU V9fsPDU;
 121 typedef struct V9fsState V9fsState;
 122 typedef struct V9fsTransport V9fsTransport;
 123
 124 typedef struct {
 125     uint32_t size_le;
 126     uint8_t id;
 127     uint16_t tag_le;
 128 } QEMU_PACKED P9MsgHeader;
 129 /* According to the specification, 9p messages start with a 7-byte header.
 130  * Since most of the code uses this header size in literal form, we must be
 131  * sure this is indeed the case.
 132  */
 133 QEMU_BUILD_BUG_ON(sizeof(P9MsgHeader) != 7);
 134
 135 struct V9fsPDU
 136 {
 137     uint32_t size;
 138     uint16_t tag;
 139     uint8_t id;
 140     uint8_t cancelled;
 141     CoQueue complete;
 142     V9fsState *s;
 143     QLIST_ENTRY(V9fsPDU) next;
 144     uint32_t idx;
 145 };
 146
 147
 148 /* FIXME
 149  * 1) change user needs to set groups and stuff
 150  */
 151
 152 #define MAX_REQ         128
 153 #define MAX_TAG_LEN     32
 154
 155 #define BUG_ON(cond) assert(!(cond))
 156
 157 typedef struct V9fsFidState V9fsFidState;
 158
 159 enum {
 160     P9_FID_NONE = 0,
 161     P9_FID_FILE,
 162     P9_FID_DIR,
 163     P9_FID_XATTR,
 164 };
 165
 166 typedef struct V9fsConf
 167 {
 168     /* tag name for the device */
 169     char *tag;
 170     char *fsdev_id;
 171 } V9fsConf;
 172
 173 /* 9p2000.L xattr flags (matches Linux values) */
 174 #define P9_XATTR_CREATE 1
 175 #define P9_XATTR_REPLACE 2
 176
 177 typedef struct V9fsXattr
 178 {
 179     uint64_t copied_len;
 180     uint64_t len;
 181     void *value;
 182     V9fsString name;
 183     int flags;
 184     bool xattrwalk_fid;
 185 } V9fsXattr;
 186
 187 typedef struct V9fsDir {
 188     DIR *stream;
 189     QemuMutex readdir_mutex;
 190 } V9fsDir;
 191
 192 static inline void v9fs_readdir_lock(V9fsDir *dir)
 193 {
 194     qemu_mutex_lock(&dir->readdir_mutex);
 195 }
 196
 197 static inline void v9fs_readdir_unlock(V9fsDir *dir)
 198 {
 199     qemu_mutex_unlock(&dir->readdir_mutex);
 200 }
 201
 202 static inline void v9fs_readdir_init(V9fsDir *dir)
 203 {
 204     qemu_mutex_init(&dir->readdir_mutex);
 205 }
 206
 207 /*
 208  * Filled by fs driver on open and other
 209  * calls.
 210  */
 211 union V9fsFidOpenState {
 212     int fd;
 213     V9fsDir dir;
 214     V9fsXattr xattr;
 215     /*
 216      * private pointer for fs drivers, that
 217      * have its own internal representation of
 218      * open files.
 219      */
 220     void *private;
 221 };
 222
 223 struct V9fsFidState
 224 {
 225     int fid_type;
 226     int32_t fid;
 227     V9fsPath path;
 228     V9fsFidOpenState fs;
 229     V9fsFidOpenState fs_reclaim;
 230     int flags;
 231     int open_flags;
 232     uid_t uid;
 233     int ref;
 234     int clunked;
 235     V9fsFidState *next;
 236     V9fsFidState *rclm_lst;
 237 };
 238
 239 typedef enum AffixType_t {
 240     AffixType_Prefix,
 241     AffixType_Suffix, /* A.k.a. postfix. */
 242 } AffixType_t;
 243
 244 /**
 245  * @brief Unique affix of variable length.
 246  *
 247  * An affix is (currently) either a suffix or a prefix, which is either
 248  * going to be prepended (prefix) or appended (suffix) with some other
 249  * number for the goal to generate unique numbers. Accordingly the
 250  * suffixes (or prefixes) we generate @b must all have the mathematical
 251  * property of being suffix-free (or prefix-free in case of prefixes)
 252  * so that no matter what number we concatenate the affix with, that we
 253  * always reliably get unique numbers as result after concatenation.
 254  */
 255 typedef struct VariLenAffix {
 256     AffixType_t type; /* Whether this affix is a suffix or a prefix. */
 257     uint64_t value; /* Actual numerical value of this affix. */
 258     /*
 259      * Lenght of the affix, that is how many (of the lowest) bits of @c value
 260      * must be used for appending/prepending this affix to its final resulting,
 261      * unique number.
 262      */
 263     int bits;
 264 } VariLenAffix;
 265
 266 /* See qid_inode_prefix_hash_bits(). */
 267 typedef struct {
 268     dev_t dev; /* FS device on host. */
 269     /*
 270      * How many (high) bits of the original inode number shall be used for
 271      * hashing.
 272      */
 273     int prefix_bits;
 274 } QpdEntry;
 275
 276 /* QID path prefix entry, see stat_to_qid */
 277 typedef struct {
 278     dev_t dev;
 279     uint16_t ino_prefix;
 280     uint32_t qp_affix_index;
 281     VariLenAffix qp_affix;
 282 } QppEntry;
 283
 284 /* QID path full entry, as above */
 285 typedef struct {
 286     dev_t dev;
 287     ino_t ino;
 288     uint64_t path;
 289 } QpfEntry;
 290
 291 struct V9fsState
 292 {
 293     QLIST_HEAD(, V9fsPDU) free_list;
 294     QLIST_HEAD(, V9fsPDU) active_list;
 295     V9fsFidState *fid_list;
 296     FileOperations *ops;
 297     FsContext ctx;
 298     char *tag;
 299     P9ProtoVersion proto_version;
 300     int32_t msize;
 301     V9fsPDU pdus[MAX_REQ];
 302     const V9fsTransport *transport;
 303     /*
 304      * lock ensuring atomic path update
 305      * on rename.
 306      */
 307     CoRwlock rename_lock;
 308     int32_t root_fid;
 309     Error *migration_blocker;
 310     V9fsConf fsconf;
 311     V9fsQID root_qid;
 312     dev_t dev_id;
 313     struct qht qpd_table;
 314     struct qht qpp_table;
 315     struct qht qpf_table;
 316     uint64_t qp_ndevices; /* Amount of entries in qpd_table. */
 317     uint16_t qp_affix_next;
 318     uint64_t qp_fullpath_next;
 319 };
 320
 321 /* 9p2000.L open flags */
 322 #define P9_DOTL_RDONLY        00000000
 323 #define P9_DOTL_WRONLY        00000001
 324 #define P9_DOTL_RDWR          00000002
 325 #define P9_DOTL_NOACCESS      00000003
 326 #define P9_DOTL_CREATE        00000100
 327 #define P9_DOTL_EXCL          00000200
 328 #define P9_DOTL_NOCTTY        00000400
 329 #define P9_DOTL_TRUNC         00001000
 330 #define P9_DOTL_APPEND        00002000
 331 #define P9_DOTL_NONBLOCK      00004000
 332 #define P9_DOTL_DSYNC         00010000
 333 #define P9_DOTL_FASYNC        00020000
 334 #define P9_DOTL_DIRECT        00040000
 335 #define P9_DOTL_LARGEFILE     00100000
 336 #define P9_DOTL_DIRECTORY     00200000
 337 #define P9_DOTL_NOFOLLOW      00400000
 338 #define P9_DOTL_NOATIME       01000000
 339 #define P9_DOTL_CLOEXEC       02000000
 340 #define P9_DOTL_SYNC          04000000
 341
 342 /* 9p2000.L at flags */
 343 #define P9_DOTL_AT_REMOVEDIR         0x200
 344
 345 /* 9P2000.L lock type */
 346 #define P9_LOCK_TYPE_RDLCK 0
 347 #define P9_LOCK_TYPE_WRLCK 1
 348 #define P9_LOCK_TYPE_UNLCK 2
 349
 350 #define P9_LOCK_SUCCESS 0
 351 #define P9_LOCK_BLOCKED 1
 352 #define P9_LOCK_ERROR 2
 353 #define P9_LOCK_GRACE 3
 354
 355 #define P9_LOCK_FLAGS_BLOCK 1
 356 #define P9_LOCK_FLAGS_RECLAIM 2
 357
 358 typedef struct V9fsFlock
 359 {
 360     uint8_t type;
 361     uint32_t flags;
 362     uint64_t start; /* absolute offset */
 363     uint64_t length;
 364     uint32_t proc_id;
 365     V9fsString client_id;
 366 } V9fsFlock;
 367
 368 typedef struct V9fsGetlock
 369 {
 370     uint8_t type;
 371     uint64_t start; /* absolute offset */
 372     uint64_t length;
 373     uint32_t proc_id;
 374     V9fsString client_id;
 375 } V9fsGetlock;
 376
 377 extern int open_fd_hw;
 378 extern int total_open_fd;
 379
 380 static inline void v9fs_path_write_lock(V9fsState *s)
 381 {
 382     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 383         qemu_co_rwlock_wrlock(&s->rename_lock);
 384     }
 385 }
 386
 387 static inline void v9fs_path_read_lock(V9fsState *s)
 388 {
 389     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 390         qemu_co_rwlock_rdlock(&s->rename_lock);
 391     }
 392 }
 393
 394 static inline void v9fs_path_unlock(V9fsState *s)
 395 {
 396     if (s->ctx.export_flags & V9FS_PATHNAME_FSCONTEXT) {
 397         qemu_co_rwlock_unlock(&s->rename_lock);
 398     }
 399 }
 400
 401 static inline uint8_t v9fs_request_cancelled(V9fsPDU *pdu)
 402 {
 403     return pdu->cancelled;
 404 }
 405
 406 void coroutine_fn v9fs_reclaim_fd(V9fsPDU *pdu);
 407 void v9fs_path_init(V9fsPath *path);
 408 void v9fs_path_free(V9fsPath *path);
 409 void v9fs_path_sprintf(V9fsPath *path, const char *fmt, ...);
 410 void v9fs_path_copy(V9fsPath *dst, const V9fsPath *src);
 411 int v9fs_name_to_path(V9fsState *s, V9fsPath *dirpath,
 412                       const char *name, V9fsPath *path);
 413 int v9fs_device_realize_common(V9fsState *s, const V9fsTransport *t,
 414                                Error **errp);
 415 void v9fs_device_unrealize_common(V9fsState *s, Error **errp);
 416
 417 V9fsPDU *pdu_alloc(V9fsState *s);
 418 void pdu_free(V9fsPDU *pdu);
 419 void pdu_submit(V9fsPDU *pdu, P9MsgHeader *hdr);
 420 void v9fs_reset(V9fsState *s);
 421
 422 struct V9fsTransport {
 423     ssize_t     (*pdu_vmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
 424                                 va_list ap);
 425     ssize_t     (*pdu_vunmarshal)(V9fsPDU *pdu, size_t offset, const char *fmt,
 426                                   va_list ap);
 427     void        (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
 428                                         unsigned int *pniov, size_t size);
 429     void        (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
 430                                          unsigned int *pniov, size_t size);
 431     void        (*push_and_notify)(V9fsPDU *pdu);
 432 };
 433
 434 #endif