code.grnet.gr Git - archipelago/blob - xseg/peers/blockd.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <sys/types.h>
   5 #include <sys/stat.h>
   6 #include <unistd.h>
   7 #include <string.h>
   8 #include <fcntl.h>
   9 #include <errno.h>
  10 #include <aio.h>
  11 #include <signal.h>
  12
  13 #include <xseg/xseg.h>
  14
  15 static int usage(void)
  16 {
  17         printf("Usage: ./blockd <path_to_disk_image> [options]\n"
  18                 "Options: [-p portno]\n"
  19                 "         [-s image size in bytes]\n"
  20                 "         [-g type:name:nr_ports:nr_requests:request_size:extra_size:page_shift]\n"
  21                 "         [-n nr_parallel_ops]\n");
  22         return 1;
  23 }
  24
  25 struct io {
  26         struct aiocb cb;
  27         struct xseg_request *req;
  28         ssize_t retval;
  29 };
  30
  31 struct store {
  32         struct xseg *xseg;
  33         struct xseg_port *xport;
  34         uint32_t portno;
  35         int fd;
  36         uint64_t size;
  37         struct io *ios;
  38         struct xq free_ops;
  39         char *free_bufs;
  40         struct xq pending_ops;
  41         char *pending_bufs;
  42         long nr_ops;
  43         struct sigevent sigevent;
  44 };
  45
  46 static unsigned long sigaction_count;
  47
  48 static void sigaction_handler(int sig, siginfo_t *siginfo, void *arg)
  49 {
  50         sigaction_count ++;
  51 }
  52
  53 static struct io *alloc_io(struct store *store)
  54 {
  55         xqindex idx = xq_pop_head(&store->free_ops);
  56         if (idx == None)
  57                 return NULL;
  58         return store->ios + idx;
  59 }
  60
  61 static inline void free_io(struct store *store, struct io *io)
  62 {
  63         xqindex idx = io - store->ios;
  64         io->req = NULL;
  65         xq_append_head(&store->free_ops, idx);
  66 }
  67
  68 static inline void pending_io(struct store *store, struct io *io)
  69 {
  70         xqindex idx = io - store->ios;
  71         xq_append_head(&store->pending_ops, idx);
  72 }
  73
  74 static inline struct io *get_pending_io(struct store *store)
  75 {
  76         xqindex idx = xq_pop_head(&store->pending_ops);
  77         if (idx == None)
  78                 return NULL;
  79         return store->ios + idx;
  80 }
  81
  82 static void log_io(char *msg, struct io *io)
  83 {
  84         char name[64], data[64];
  85         /* null terminate name in case of req->name is less than 63 characters,
  86          * and next character after name (aka first byte of next buffer) is not
  87          * null
  88          */
  89         unsigned int end = (io->req->namesize > 63) ? 63 : io->req->namesize;
  90         strncpy(name, io->req->name, end);
  91         name[end] = 0;
  92         strncpy(data, io->req->data, 63);
  93         data[63] = 0;
  94         printf("%s: fd:%u, op:%u %llu:%lu retval: %lu, reqstate: %u\n"
  95                 "name[%u]:'%s', data[%llu]:\n%s------------------\n\n",
  96                 msg,
  97                 (unsigned int)io->cb.aio_fildes,
  98                 (unsigned int)io->req->op,
  99                 (unsigned long long)io->cb.aio_offset,
 100                 (unsigned long)io->cb.aio_nbytes,
 101                 (unsigned long)io->retval,
 102                 (unsigned int)io->req->state,
 103                 (unsigned int)io->req->namesize, name,
 104                 (unsigned long long)io->req->datasize, data);
 105 }
 106
 107 static void complete(struct store *store, struct io *io)
 108 {
 109         struct xseg_request *req = io->req;
 110         req->state |= XS_SERVED;
 111         log_io("complete", io);
 112         xseg_respond(store->xseg, req->portno, req);
 113         xseg_signal(store->xseg, req->portno);
 114         free_io(store, io);
 115 }
 116
 117 static void fail(struct store *store, struct io *io)
 118 {
 119         struct xseg_request *req = io->req;
 120         req->state |= XS_ERROR;
 121         log_io("fail", io);
 122         xseg_respond(store->xseg, req->portno, req);
 123         xseg_signal(store->xseg, req->portno);
 124         free_io(store, io);
 125 }
 126
 127 static void pending(struct store *store, struct io *io)
 128 {
 129         io->req->state = XS_PENDING;
 130         pending_io(store, io);
 131 }
 132
 133 static void handle_unknown(struct store *store, struct io *io)
 134 {
 135         struct xseg_request *req = io->req;
 136         snprintf(req->data, req->datasize, "unknown request op");
 137         fail(store, io);
 138 }
 139
 140 static inline void prepare_io(struct store *store, struct io *io)
 141 {
 142         io->cb.aio_fildes = store->fd;
 143         io->cb.aio_sigevent = store->sigevent;
 144         /* cb->aio_sigevent.sigev_value.sival_int = fd; */
 145 }
 146
 147 static void handle_read_write(struct store *store, struct io *io)
 148 {
 149         int r;
 150         struct xseg_request *req = io->req;
 151         struct aiocb *cb = &io->cb;
 152
 153         if (req->state != XS_ACCEPTED) {
 154                 if (io->retval > 0)
 155                         req->serviced += io->retval;
 156                 else
 157                         req->datasize = req->serviced;
 158
 159                 if (req->serviced >= req->datasize) {
 160                         complete(store, io);
 161                         return;
 162                 }
 163         }
 164
 165         if (req != io->req)
 166                 printf("0.%p vs %p!\n", (void *)req, (void *)io->req);
 167         if (!req->size) {
 168                 if (req->flags & (XSEG_FLUSH | XSEG_FUA)) {
 169                         /* for now, no FLUSH/FUA support.
 170                          * note that with FLUSH/size == 0
 171                          * there will probably be a (uint64_t)-1 offset */
 172                         complete(store, io);
 173                         return;
 174                 } else {
 175                         complete(store, io);
 176                         return;
 177                 }
 178         }
 179
 180         prepare_io(store, io);
 181         cb->aio_buf = req->data + req->serviced;
 182         cb->aio_nbytes = req->datasize - req->serviced;
 183         cb->aio_offset = req->offset + req->serviced;
 184
 185         switch (req->op) {
 186         case X_READ:
 187                 r = aio_read(cb);
 188                 break;
 189         case X_WRITE:
 190                 r = aio_write(cb);
 191                 break;
 192         default:
 193                 snprintf(req->data, req->datasize,
 194                          "wtf, corrupt op %u?\n", req->op);
 195                 fail(store, io);
 196                 return;
 197         }
 198
 199         if (r) {
 200                 strerror_r(errno, req->data, req->datasize);
 201                 fail(store, io);
 202                 return;
 203         }
 204
 205         pending(store, io);
 206 }
 207
 208 static void dispatch(struct store *store, struct io *io)
 209 {
 210         switch (io->req->op) {
 211         case X_READ:
 212         case X_WRITE:
 213                 handle_read_write(store, io); break;
 214         case X_SYNC:
 215         default:
 216                 handle_unknown(store, io);
 217         }
 218 }
 219
 220 static void handle_pending(struct store *store, struct io *io)
 221 {
 222         int r = aio_error(&io->cb);
 223         if (r == EINPROGRESS) {
 224                 pending(store, io);
 225                 return;
 226         }
 227
 228         io->retval = aio_return(&io->cb);
 229         if (r) {
 230                 fail(store, io);
 231                 return;
 232         }
 233
 234         dispatch(store, io);
 235 }
 236
 237 static void handle_accepted(struct store *store, struct io *io)
 238 {
 239         struct xseg_request *req = io->req;
 240         req->serviced = 0;
 241         req->state = XS_ACCEPTED;
 242         io->retval = 0;
 243         dispatch(store, io);
 244 }
 245
 246 static int blockd_loop(struct store *store)
 247 {
 248         struct xseg *xseg = store->xseg;
 249         uint32_t portno = store->portno;
 250         struct io *io;
 251         struct xseg_request *accepted;
 252
 253         for (;;) {
 254                 accepted = NULL;
 255                 xseg_prepare_wait(xseg, portno);
 256                 io = alloc_io(store);
 257                 if (io) {
 258                         accepted = xseg_accept(xseg, portno);
 259                         if (accepted) {
 260                                 xseg_cancel_wait(xseg, portno);
 261                                 io->req = accepted;
 262                                 handle_accepted(store, io);
 263                         } else
 264                                 free_io(store, io);
 265                 }
 266
 267                 io = get_pending_io(store);
 268                 if (io) {
 269                         xseg_cancel_wait(xseg, portno);
 270                         handle_pending(store, io);
 271                 }
 272
 273                 if (!io && !accepted)
 274                         xseg_wait_signal(xseg, portno, 10000);
 275         }
 276
 277         return 0;
 278 }
 279
 280 static struct xseg *join(char *spec)
 281 {
 282         struct xseg_config config;
 283         struct xseg *xseg;
 284
 285         (void)xseg_parse_spec(spec, &config);
 286         xseg = xseg_join(config.type, config.name);
 287         if (xseg)
 288                 return xseg;
 289
 290         (void)xseg_create(&config);
 291         return xseg_join(config.type, config.name);
 292 }
 293
 294 static int blockd(char *path, unsigned long size, uint32_t nr_ops,
 295                   char *spec, long portno)
 296 {
 297         struct stat stat;
 298         struct sigaction sa;
 299         struct store *store;
 300         int r;
 301
 302         store = malloc(sizeof(struct store));
 303         if (!store) {
 304                 perror("malloc");
 305                 return -1;
 306         }
 307
 308         store->fd = open(path, O_RDWR);
 309         while (store->fd < 0) {
 310                 if (errno == ENOENT && size)
 311                         store->fd = open(path, O_RDWR | O_CREAT, 0600);
 312                         if (store->fd >= 0)
 313                                 break;
 314                 perror(path);
 315                 return store->fd;
 316         }
 317
 318         if (size == 0) {
 319                 r = fstat(store->fd, &stat);
 320                 if (r < 0) {
 321                         perror(path);
 322                         return r;
 323                 }
 324                 size = stat.st_size;
 325                 if (size == 0) {
 326                         fprintf(stderr, "size cannot be zero\n");
 327                         return -1;
 328                 }
 329         }
 330
 331         lseek(store->fd, size-1, SEEK_SET);
 332         if (write(store->fd, &r, 1) != 1) {
 333                 perror("write");
 334                 return -1;
 335         }
 336
 337         /*
 338         r = daemon(1, 1);
 339         if (r < 0)
 340                 return r;
 341                 */
 342
 343         store->sigevent.sigev_notify = SIGEV_SIGNAL;
 344         store->sigevent.sigev_signo = SIGIO;
 345         sa.sa_sigaction = sigaction_handler;
 346         sa.sa_flags = SA_SIGINFO;
 347         if (sigemptyset(&sa.sa_mask))
 348                 perror("sigemptyset");
 349
 350         if (sigaction(SIGIO, &sa, NULL)) {
 351                 perror("sigaction");
 352                 return -1;
 353         }
 354
 355         store->nr_ops = nr_ops;
 356         store->free_bufs = calloc(nr_ops, sizeof(xqindex));
 357         if (!store->free_bufs)
 358                 goto malloc_fail;
 359
 360         store->pending_bufs = calloc(nr_ops, sizeof(xqindex));
 361         if (!store->pending_bufs)
 362                 goto malloc_fail;
 363
 364         store->ios = calloc(nr_ops, sizeof(struct io));
 365         if (!store->ios) {
 366 malloc_fail:
 367                 perror("malloc");
 368                 return -1;
 369         }
 370
 371         xq_init_seq(&store->free_ops, nr_ops, nr_ops, store->free_bufs);
 372         xq_init_empty(&store->pending_ops, nr_ops, store->pending_bufs);
 373
 374         if (xseg_initialize("posix")) {
 375                 printf("cannot initialize library\n");
 376                 return -1;
 377         }
 378         store->xseg = join(spec);
 379         if (!store->xseg)
 380                 return -1;
 381
 382         store->xport = xseg_bind_port(store->xseg, portno);
 383         if (!store->xport) {
 384                 printf("cannot bind to port %ld\n", portno);
 385                 return -1;
 386         }
 387
 388         store->portno = xseg_portno(store->xseg, store->xport);
 389         printf("blockd on port %u/%u\n",
 390                 store->portno, store->xseg->config.nr_ports);
 391
 392         return blockd_loop(store);
 393 }
 394
 395 int main(int argc, char **argv)
 396 {
 397         char *path, *spec = "";
 398         unsigned long size;
 399         int i;
 400         long portno;
 401         uint32_t nr_ops;
 402
 403         if (argc < 2)
 404                 return usage();
 405
 406         path = argv[1];
 407         size = 0;
 408         portno = -1;
 409         nr_ops = 0;
 410
 411         for (i = 2; i < argc; i++) {
 412                 if (!strcmp(argv[i], "-g") && i + 1 < argc) {
 413                         spec = argv[i+1];
 414                         i += 1;
 415                         continue;
 416                 }
 417
 418                 if (!strcmp(argv[i], "-s") && i + 1 < argc) {
 419                         size = strtoul(argv[i+1], NULL, 10);
 420                         i += 1;
 421                         continue;
 422                 }
 423
 424                 if (!strcmp(argv[i], "-p") && i + 1 < argc) {
 425                         portno = strtoul(argv[i+1], NULL, 10);
 426                         i += 1;
 427                         continue;
 428                 }
 429
 430                 if (!strcmp(argv[i], "-p") && i + 1 < argc) {
 431                         nr_ops = strtoul(argv[i+1], NULL, 10);
 432                         i += 1;
 433                         continue;
 434                 }
 435         }
 436
 437         if (nr_ops <= 0)
 438                 nr_ops = 16;
 439
 440         return blockd(path, size, nr_ops, spec, portno);
 441 }
 442