fs/coda/upcall.c

   1 /*
   2  * Mostly platform independent upcall operations to Venus:
   3  *  -- upcalls
   4  *  -- upcall routines
   5  *
   6  * Linux 2.0 version
   7  * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk>,
   8  * Michael Callahan <callahan@maths.ox.ac.uk>
   9  *
  10  * Redone for Linux 2.1
  11  * Copyright (C) 1997 Carnegie Mellon University
  12  *
  13  * Carnegie Mellon University encourages users of this code to contribute
  14  * improvements to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
  15  */
  16
  17 #include <asm/system.h>
  18 #include <linux/signal.h>
  19 #include <linux/sched.h>
  20 #include <linux/types.h>
  21 #include <linux/kernel.h>
  22 #include <linux/mm.h>
  23 #include <linux/time.h>
  24 #include <linux/fs.h>
  25 #include <linux/file.h>
  26 #include <linux/stat.h>
  27 #include <linux/errno.h>
  28 #include <linux/string.h>
  29 #include <asm/uaccess.h>
  30 #include <linux/vmalloc.h>
  31 #include <linux/vfs.h>
  32
  33 #include <linux/coda.h>
  34 #include <linux/coda_linux.h>
  35 #include <linux/coda_psdev.h>
  36 #include <linux/coda_fs_i.h>
  37 #include <linux/coda_cache.h>
  38
  39 #include "coda_int.h"
  40
  41 static int coda_upcall(struct venus_comm *vc, int inSize, int *outSize,
  42                        union inputArgs *buffer);
  43
  44 static void *alloc_upcall(int opcode, int size)
  45 {
  46         union inputArgs *inp;
  47
  48         CODA_ALLOC(inp, union inputArgs *, size);
  49         if (!inp)
  50                 return ERR_PTR(-ENOMEM);
  51
  52         inp->ih.opcode = opcode;
  53         inp->ih.pid = current->pid;
  54         inp->ih.pgid = task_pgrp_nr(current);
  55         inp->ih.uid = current_fsuid();
  56
  57         return (void*)inp;
  58 }
  59
  60 #define UPARG(op)\
  61 do {\
  62         inp = (union inputArgs *)alloc_upcall(op, insize); \
  63         if (IS_ERR(inp)) { return PTR_ERR(inp); }\
  64         outp = (union outputArgs *)(inp); \
  65         outsize = insize; \
  66 } while (0)
  67
  68 #define INSIZE(tag) sizeof(struct coda_ ## tag ## _in)
  69 #define OUTSIZE(tag) sizeof(struct coda_ ## tag ## _out)
  70 #define SIZE(tag)  max_t(unsigned int, INSIZE(tag), OUTSIZE(tag))
  71
  72
  73 /* the upcalls */
  74 int venus_rootfid(struct super_block *sb, struct CodaFid *fidp)
  75 {
  76         union inputArgs *inp;
  77         union outputArgs *outp;
  78         int insize, outsize, error;
  79
  80         insize = SIZE(root);
  81         UPARG(CODA_ROOT);
  82
  83         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
  84         if (!error)
  85                 *fidp = outp->coda_root.VFid;
  86
  87         CODA_FREE(inp, insize);
  88         return error;
  89 }
  90
  91 int venus_getattr(struct super_block *sb, struct CodaFid *fid,
  92                      struct coda_vattr *attr)
  93 {
  94         union inputArgs *inp;
  95         union outputArgs *outp;
  96         int insize, outsize, error;
  97
  98         insize = SIZE(getattr);
  99         UPARG(CODA_GETATTR);
 100         inp->coda_getattr.VFid = *fid;
 101
 102         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 103         if (!error)
 104                 *attr = outp->coda_getattr.attr;
 105
 106         CODA_FREE(inp, insize);
 107         return error;
 108 }
 109
 110 int venus_setattr(struct super_block *sb, struct CodaFid *fid,
 111                   struct coda_vattr *vattr)
 112 {
 113         union inputArgs *inp;
 114         union outputArgs *outp;
 115         int insize, outsize, error;
 116
 117         insize = SIZE(setattr);
 118         UPARG(CODA_SETATTR);
 119
 120         inp->coda_setattr.VFid = *fid;
 121         inp->coda_setattr.attr = *vattr;
 122
 123         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 124
 125         CODA_FREE(inp, insize);
 126         return error;
 127 }
 128
 129 int venus_lookup(struct super_block *sb, struct CodaFid *fid,
 130                     const char *name, int length, int * type,
 131                     struct CodaFid *resfid)
 132 {
 133         union inputArgs *inp;
 134         union outputArgs *outp;
 135         int insize, outsize, error;
 136         int offset;
 137
 138         offset = INSIZE(lookup);
 139         insize = max_t(unsigned int, offset + length +1, OUTSIZE(lookup));
 140         UPARG(CODA_LOOKUP);
 141
 142         inp->coda_lookup.VFid = *fid;
 143         inp->coda_lookup.name = offset;
 144         inp->coda_lookup.flags = CLU_CASE_SENSITIVE;
 145         /* send Venus a null terminated string */
 146         memcpy((char *)(inp) + offset, name, length);
 147         *((char *)inp + offset + length) = '\0';
 148
 149         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 150         if (!error) {
 151                 *resfid = outp->coda_lookup.VFid;
 152                 *type = outp->coda_lookup.vtype;
 153         }
 154
 155         CODA_FREE(inp, insize);
 156         return error;
 157 }
 158
 159 int venus_close(struct super_block *sb, struct CodaFid *fid, int flags,
 160                 vuid_t uid)
 161 {
 162         union inputArgs *inp;
 163         union outputArgs *outp;
 164         int insize, outsize, error;
 165
 166         insize = SIZE(release);
 167         UPARG(CODA_CLOSE);
 168
 169         inp->ih.uid = uid;
 170         inp->coda_close.VFid = *fid;
 171         inp->coda_close.flags = flags;
 172
 173         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 174
 175         CODA_FREE(inp, insize);
 176         return error;
 177 }
 178
 179 int venus_open(struct super_block *sb, struct CodaFid *fid,
 180                   int flags, struct file **fh)
 181 {
 182         union inputArgs *inp;
 183         union outputArgs *outp;
 184         int insize, outsize, error;
 185
 186         insize = SIZE(open_by_fd);
 187         UPARG(CODA_OPEN_BY_FD);
 188
 189         inp->coda_open_by_fd.VFid = *fid;
 190         inp->coda_open_by_fd.flags = flags;
 191
 192         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 193         if (!error)
 194                 *fh = outp->coda_open_by_fd.fh;
 195
 196         CODA_FREE(inp, insize);
 197         return error;
 198 }
 199
 200 int venus_mkdir(struct super_block *sb, struct CodaFid *dirfid,
 201                    const char *name, int length,
 202                    struct CodaFid *newfid, struct coda_vattr *attrs)
 203 {
 204         union inputArgs *inp;
 205         union outputArgs *outp;
 206         int insize, outsize, error;
 207         int offset;
 208
 209         offset = INSIZE(mkdir);
 210         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(mkdir));
 211         UPARG(CODA_MKDIR);
 212
 213         inp->coda_mkdir.VFid = *dirfid;
 214         inp->coda_mkdir.attr = *attrs;
 215         inp->coda_mkdir.name = offset;
 216         /* Venus must get null terminated string */
 217         memcpy((char *)(inp) + offset, name, length);
 218         *((char *)inp + offset + length) = '\0';
 219
 220         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 221         if (!error) {
 222                 *attrs = outp->coda_mkdir.attr;
 223                 *newfid = outp->coda_mkdir.VFid;
 224         }
 225
 226         CODA_FREE(inp, insize);
 227         return error;
 228 }
 229
 230
 231 int venus_rename(struct super_block *sb, struct CodaFid *old_fid,
 232                  struct CodaFid *new_fid, size_t old_length,
 233                  size_t new_length, const char *old_name,
 234                  const char *new_name)
 235 {
 236         union inputArgs *inp;
 237         union outputArgs *outp;
 238         int insize, outsize, error;
 239         int offset, s;
 240
 241         offset = INSIZE(rename);
 242         insize = max_t(unsigned int, offset + new_length + old_length + 8,
 243                      OUTSIZE(rename));
 244         UPARG(CODA_RENAME);
 245
 246         inp->coda_rename.sourceFid = *old_fid;
 247         inp->coda_rename.destFid =  *new_fid;
 248         inp->coda_rename.srcname = offset;
 249
 250         /* Venus must receive an null terminated string */
 251         s = ( old_length & ~0x3) +4; /* round up to word boundary */
 252         memcpy((char *)(inp) + offset, old_name, old_length);
 253         *((char *)inp + offset + old_length) = '\0';
 254
 255         /* another null terminated string for Venus */
 256         offset += s;
 257         inp->coda_rename.destname = offset;
 258         s = ( new_length & ~0x3) +4; /* round up to word boundary */
 259         memcpy((char *)(inp) + offset, new_name, new_length);
 260         *((char *)inp + offset + new_length) = '\0';
 261
 262         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 263
 264         CODA_FREE(inp, insize);
 265         return error;
 266 }
 267
 268 int venus_create(struct super_block *sb, struct CodaFid *dirfid,
 269                  const char *name, int length, int excl, int mode,
 270                  struct CodaFid *newfid, struct coda_vattr *attrs)
 271 {
 272         union inputArgs *inp;
 273         union outputArgs *outp;
 274         int insize, outsize, error;
 275         int offset;
 276
 277         offset = INSIZE(create);
 278         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(create));
 279         UPARG(CODA_CREATE);
 280
 281         inp->coda_create.VFid = *dirfid;
 282         inp->coda_create.attr.va_mode = mode;
 283         inp->coda_create.excl = excl;
 284         inp->coda_create.mode = mode;
 285         inp->coda_create.name = offset;
 286
 287         /* Venus must get null terminated string */
 288         memcpy((char *)(inp) + offset, name, length);
 289         *((char *)inp + offset + length) = '\0';
 290
 291         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 292         if (!error) {
 293                 *attrs = outp->coda_create.attr;
 294                 *newfid = outp->coda_create.VFid;
 295         }
 296
 297         CODA_FREE(inp, insize);
 298         return error;
 299 }
 300
 301 int venus_rmdir(struct super_block *sb, struct CodaFid *dirfid,
 302                     const char *name, int length)
 303 {
 304         union inputArgs *inp;
 305         union outputArgs *outp;
 306         int insize, outsize, error;
 307         int offset;
 308
 309         offset = INSIZE(rmdir);
 310         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(rmdir));
 311         UPARG(CODA_RMDIR);
 312
 313         inp->coda_rmdir.VFid = *dirfid;
 314         inp->coda_rmdir.name = offset;
 315         memcpy((char *)(inp) + offset, name, length);
 316         *((char *)inp + offset + length) = '\0';
 317
 318         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 319
 320         CODA_FREE(inp, insize);
 321         return error;
 322 }
 323
 324 int venus_remove(struct super_block *sb, struct CodaFid *dirfid,
 325                     const char *name, int length)
 326 {
 327         union inputArgs *inp;
 328         union outputArgs *outp;
 329         int error=0, insize, outsize, offset;
 330
 331         offset = INSIZE(remove);
 332         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(remove));
 333         UPARG(CODA_REMOVE);
 334
 335         inp->coda_remove.VFid = *dirfid;
 336         inp->coda_remove.name = offset;
 337         memcpy((char *)(inp) + offset, name, length);
 338         *((char *)inp + offset + length) = '\0';
 339
 340         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 341
 342         CODA_FREE(inp, insize);
 343         return error;
 344 }
 345
 346 int venus_readlink(struct super_block *sb, struct CodaFid *fid,
 347                       char *buffer, int *length)
 348 {
 349         union inputArgs *inp;
 350         union outputArgs *outp;
 351         int insize, outsize, error;
 352         int retlen;
 353         char *result;
 354
 355         insize = max_t(unsigned int,
 356                      INSIZE(readlink), OUTSIZE(readlink)+ *length + 1);
 357         UPARG(CODA_READLINK);
 358
 359         inp->coda_readlink.VFid = *fid;
 360
 361         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 362         if (!error) {
 363                 retlen = outp->coda_readlink.count;
 364                 if ( retlen > *length )
 365                         retlen = *length;
 366                 *length = retlen;
 367                 result =  (char *)outp + (long)outp->coda_readlink.data;
 368                 memcpy(buffer, result, retlen);
 369                 *(buffer + retlen) = '\0';
 370         }
 371
 372         CODA_FREE(inp, insize);
 373         return error;
 374 }
 375
 376
 377
 378 int venus_link(struct super_block *sb, struct CodaFid *fid,
 379                   struct CodaFid *dirfid, const char *name, int len )
 380 {
 381         union inputArgs *inp;
 382         union outputArgs *outp;
 383         int insize, outsize, error;
 384         int offset;
 385
 386         offset = INSIZE(link);
 387         insize = max_t(unsigned int, offset  + len + 1, OUTSIZE(link));
 388         UPARG(CODA_LINK);
 389
 390         inp->coda_link.sourceFid = *fid;
 391         inp->coda_link.destFid = *dirfid;
 392         inp->coda_link.tname = offset;
 393
 394         /* make sure strings are null terminated */
 395         memcpy((char *)(inp) + offset, name, len);
 396         *((char *)inp + offset + len) = '\0';
 397
 398         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 399
 400         CODA_FREE(inp, insize);
 401         return error;
 402 }
 403
 404 int venus_symlink(struct super_block *sb, struct CodaFid *fid,
 405                      const char *name, int len,
 406                      const char *symname, int symlen)
 407 {
 408         union inputArgs *inp;
 409         union outputArgs *outp;
 410         int insize, outsize, error;
 411         int offset, s;
 412
 413         offset = INSIZE(symlink);
 414         insize = max_t(unsigned int, offset + len + symlen + 8, OUTSIZE(symlink));
 415         UPARG(CODA_SYMLINK);
 416
 417         /*        inp->coda_symlink.attr = *tva; XXXXXX */
 418         inp->coda_symlink.VFid = *fid;
 419
 420         /* Round up to word boundary and null terminate */
 421         inp->coda_symlink.srcname = offset;
 422         s = ( symlen  & ~0x3 ) + 4;
 423         memcpy((char *)(inp) + offset, symname, symlen);
 424         *((char *)inp + offset + symlen) = '\0';
 425
 426         /* Round up to word boundary and null terminate */
 427         offset += s;
 428         inp->coda_symlink.tname = offset;
 429         s = (len & ~0x3) + 4;
 430         memcpy((char *)(inp) + offset, name, len);
 431         *((char *)inp + offset + len) = '\0';
 432
 433         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 434
 435         CODA_FREE(inp, insize);
 436         return error;
 437 }
 438
 439 int venus_fsync(struct super_block *sb, struct CodaFid *fid)
 440 {
 441         union inputArgs *inp;
 442         union outputArgs *outp;
 443         int insize, outsize, error;
 444
 445         insize=SIZE(fsync);
 446         UPARG(CODA_FSYNC);
 447
 448         inp->coda_fsync.VFid = *fid;
 449         error = coda_upcall(coda_vcp(sb), sizeof(union inputArgs),
 450                             &outsize, inp);
 451
 452         CODA_FREE(inp, insize);
 453         return error;
 454 }
 455
 456 int venus_access(struct super_block *sb, struct CodaFid *fid, int mask)
 457 {
 458         union inputArgs *inp;
 459         union outputArgs *outp;
 460         int insize, outsize, error;
 461
 462         insize = SIZE(access);
 463         UPARG(CODA_ACCESS);
 464
 465         inp->coda_access.VFid = *fid;
 466         inp->coda_access.flags = mask;
 467
 468         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 469
 470         CODA_FREE(inp, insize);
 471         return error;
 472 }
 473
 474
 475 int venus_pioctl(struct super_block *sb, struct CodaFid *fid,
 476                  unsigned int cmd, struct PioctlData *data)
 477 {
 478         union inputArgs *inp;
 479         union outputArgs *outp;
 480         int insize, outsize, error;
 481         int iocsize;
 482
 483         insize = VC_MAXMSGSIZE;
 484         UPARG(CODA_IOCTL);
 485
 486         /* build packet for Venus */
 487         if (data->vi.in_size > VC_MAXDATASIZE) {
 488                 error = -EINVAL;
 489                 goto exit;
 490         }
 491
 492         if (data->vi.out_size > VC_MAXDATASIZE) {
 493                 error = -EINVAL;
 494                 goto exit;
 495         }
 496
 497         inp->coda_ioctl.VFid = *fid;
 498
 499         /* the cmd field was mutated by increasing its size field to
 500          * reflect the path and follow args. We need to subtract that
 501          * out before sending the command to Venus.  */
 502         inp->coda_ioctl.cmd = (cmd & ~(PIOCPARM_MASK << 16));
 503         iocsize = ((cmd >> 16) & PIOCPARM_MASK) - sizeof(char *) - sizeof(int);
 504         inp->coda_ioctl.cmd |= (iocsize & PIOCPARM_MASK) <<     16;
 505
 506         /* in->coda_ioctl.rwflag = flag; */
 507         inp->coda_ioctl.len = data->vi.in_size;
 508         inp->coda_ioctl.data = (char *)(INSIZE(ioctl));
 509
 510         /* get the data out of user space */
 511         if ( copy_from_user((char*)inp + (long)inp->coda_ioctl.data,
 512                             data->vi.in, data->vi.in_size) ) {
 513                 error = -EINVAL;
 514                 goto exit;
 515         }
 516
 517         error = coda_upcall(coda_vcp(sb), SIZE(ioctl) + data->vi.in_size,
 518                             &outsize, inp);
 519
 520         if (error) {
 521                 printk("coda_pioctl: Venus returns: %d for %s\n",
 522                        error, coda_f2s(fid));
 523                 goto exit;
 524         }
 525
 526         if (outsize < (long)outp->coda_ioctl.data + outp->coda_ioctl.len) {
 527                 error = -EINVAL;
 528                 goto exit;
 529         }
 530
 531         /* Copy out the OUT buffer. */
 532         if (outp->coda_ioctl.len > data->vi.out_size) {
 533                 error = -EINVAL;
 534                 goto exit;
 535         }
 536
 537         /* Copy out the OUT buffer. */
 538         if (copy_to_user(data->vi.out,
 539                          (char *)outp + (long)outp->coda_ioctl.data,
 540                          outp->coda_ioctl.len)) {
 541                 error = -EFAULT;
 542                 goto exit;
 543         }
 544
 545  exit:
 546         CODA_FREE(inp, insize);
 547         return error;
 548 }
 549
 550 int venus_statfs(struct dentry *dentry, struct kstatfs *sfs)
 551 {
 552         union inputArgs *inp;
 553         union outputArgs *outp;
 554         int insize, outsize, error;
 555
 556         insize = max_t(unsigned int, INSIZE(statfs), OUTSIZE(statfs));
 557         UPARG(CODA_STATFS);
 558
 559         error = coda_upcall(coda_vcp(dentry->d_sb), insize, &outsize, inp);
 560         if (!error) {
 561                 sfs->f_blocks = outp->coda_statfs.stat.f_blocks;
 562                 sfs->f_bfree  = outp->coda_statfs.stat.f_bfree;
 563                 sfs->f_bavail = outp->coda_statfs.stat.f_bavail;
 564                 sfs->f_files  = outp->coda_statfs.stat.f_files;
 565                 sfs->f_ffree  = outp->coda_statfs.stat.f_ffree;
 566         }
 567
 568         CODA_FREE(inp, insize);
 569         return error;
 570 }
 571
 572 /*
 573  * coda_upcall and coda_downcall routines.
 574  */
 575 static void coda_block_signals(sigset_t *old)
 576 {
 577         spin_lock_irq(&current->sighand->siglock);
 578         *old = current->blocked;
 579
 580         sigfillset(&current->blocked);
 581         sigdelset(&current->blocked, SIGKILL);
 582         sigdelset(&current->blocked, SIGSTOP);
 583         sigdelset(&current->blocked, SIGINT);
 584
 585         recalc_sigpending();
 586         spin_unlock_irq(&current->sighand->siglock);
 587 }
 588
 589 static void coda_unblock_signals(sigset_t *old)
 590 {
 591         spin_lock_irq(&current->sighand->siglock);
 592         current->blocked = *old;
 593         recalc_sigpending();
 594         spin_unlock_irq(&current->sighand->siglock);
 595 }
 596
 597 /* Don't allow signals to interrupt the following upcalls before venus
 598  * has seen them,
 599  * - CODA_CLOSE or CODA_RELEASE upcall  (to avoid reference count problems)
 600  * - CODA_STORE                         (to avoid data loss)
 601  */
 602 #define CODA_INTERRUPTIBLE(r) (!coda_hard && \
 603                                (((r)->uc_opcode != CODA_CLOSE && \
 604                                  (r)->uc_opcode != CODA_STORE && \
 605                                  (r)->uc_opcode != CODA_RELEASE) || \
 606                                 (r)->uc_flags & REQ_READ))
 607
 608 static inline void coda_waitfor_upcall(struct upc_req *req)
 609 {
 610         DECLARE_WAITQUEUE(wait, current);
 611         unsigned long timeout = jiffies + coda_timeout * HZ;
 612         sigset_t old;
 613         int blocked;
 614
 615         coda_block_signals(&old);
 616         blocked = 1;
 617
 618         add_wait_queue(&req->uc_sleep, &wait);
 619         for (;;) {
 620                 if (CODA_INTERRUPTIBLE(req))
 621                         set_current_state(TASK_INTERRUPTIBLE);
 622                 else
 623                         set_current_state(TASK_UNINTERRUPTIBLE);
 624
 625                 /* got a reply */
 626                 if (req->uc_flags & (REQ_WRITE | REQ_ABORT))
 627                         break;
 628
 629                 if (blocked && time_after(jiffies, timeout) &&
 630                     CODA_INTERRUPTIBLE(req))
 631                 {
 632                         coda_unblock_signals(&old);
 633                         blocked = 0;
 634                 }
 635
 636                 if (signal_pending(current)) {
 637                         list_del(&req->uc_chain);
 638                         break;
 639                 }
 640
 641                 if (blocked)
 642                         schedule_timeout(HZ);
 643                 else
 644                         schedule();
 645         }
 646         if (blocked)
 647                 coda_unblock_signals(&old);
 648
 649         remove_wait_queue(&req->uc_sleep, &wait);
 650         set_current_state(TASK_RUNNING);
 651 }
 652
 653
 654 /*
 655  * coda_upcall will return an error in the case of
 656  * failed communication with Venus _or_ will peek at Venus
 657  * reply and return Venus' error.
 658  *
 659  * As venus has 2 types of errors, normal errors (positive) and internal
 660  * errors (negative), normal errors are negated, while internal errors
 661  * are all mapped to -EINTR, while showing a nice warning message. (jh)
 662  */
 663 static int coda_upcall(struct venus_comm *vcp,
 664                        int inSize, int *outSize,
 665                        union inputArgs *buffer)
 666 {
 667         union outputArgs *out;
 668         union inputArgs *sig_inputArgs;
 669         struct upc_req *req, *sig_req;
 670         int error = 0;
 671
 672         if (!vcp->vc_inuse) {
 673                 printk(KERN_NOTICE "coda: Venus dead, not sending upcall\n");
 674                 return -ENXIO;
 675         }
 676
 677         /* Format the request message. */
 678         req = kmalloc(sizeof(struct upc_req), GFP_KERNEL);
 679         if (!req)
 680                 return -ENOMEM;
 681
 682         req->uc_data = (void *)buffer;
 683         req->uc_flags = 0;
 684         req->uc_inSize = inSize;
 685         req->uc_outSize = *outSize ? *outSize : inSize;
 686         req->uc_opcode = ((union inputArgs *)buffer)->ih.opcode;
 687         req->uc_unique = ++vcp->vc_seq;
 688         init_waitqueue_head(&req->uc_sleep);
 689
 690         /* Fill in the common input args. */
 691         ((union inputArgs *)buffer)->ih.unique = req->uc_unique;
 692
 693         /* Append msg to pending queue and poke Venus. */
 694         list_add_tail(&req->uc_chain, &vcp->vc_pending);
 695
 696         wake_up_interruptible(&vcp->vc_waitq);
 697         /* We can be interrupted while we wait for Venus to process
 698          * our request.  If the interrupt occurs before Venus has read
 699          * the request, we dequeue and return. If it occurs after the
 700          * read but before the reply, we dequeue, send a signal
 701          * message, and return. If it occurs after the reply we ignore
 702          * it. In no case do we want to restart the syscall.  If it
 703          * was interrupted by a venus shutdown (psdev_close), return
 704          * ENODEV.  */
 705
 706         /* Go to sleep.  Wake up on signals only after the timeout. */
 707         coda_waitfor_upcall(req);
 708
 709         /* Op went through, interrupt or not... */
 710         if (req->uc_flags & REQ_WRITE) {
 711                 out = (union outputArgs *)req->uc_data;
 712                 /* here we map positive Venus errors to kernel errors */
 713                 error = -out->oh.result;
 714                 *outSize = req->uc_outSize;
 715                 goto exit;
 716         }
 717
 718         error = -EINTR;
 719         if ((req->uc_flags & REQ_ABORT) || !signal_pending(current)) {
 720                 printk(KERN_WARNING "coda: Unexpected interruption.\n");
 721                 goto exit;
 722         }
 723
 724         /* Interrupted before venus read it. */
 725         if (!(req->uc_flags & REQ_READ))
 726                 goto exit;
 727
 728         /* Venus saw the upcall, make sure we can send interrupt signal */
 729         if (!vcp->vc_inuse) {
 730                 printk(KERN_INFO "coda: Venus dead, not sending signal.\n");
 731                 goto exit;
 732         }
 733
 734         error = -ENOMEM;
 735         sig_req = kmalloc(sizeof(struct upc_req), GFP_KERNEL);
 736         if (!sig_req) goto exit;
 737
 738         CODA_ALLOC((sig_req->uc_data), char *, sizeof(struct coda_in_hdr));
 739         if (!sig_req->uc_data) {
 740                 kfree(sig_req);
 741                 goto exit;
 742         }
 743
 744         error = -EINTR;
 745         sig_inputArgs = (union inputArgs *)sig_req->uc_data;
 746         sig_inputArgs->ih.opcode = CODA_SIGNAL;
 747         sig_inputArgs->ih.unique = req->uc_unique;
 748
 749         sig_req->uc_flags = REQ_ASYNC;
 750         sig_req->uc_opcode = sig_inputArgs->ih.opcode;
 751         sig_req->uc_unique = sig_inputArgs->ih.unique;
 752         sig_req->uc_inSize = sizeof(struct coda_in_hdr);
 753         sig_req->uc_outSize = sizeof(struct coda_in_hdr);
 754
 755         /* insert at head of queue! */
 756         list_add(&(sig_req->uc_chain), &vcp->vc_pending);
 757         wake_up_interruptible(&vcp->vc_waitq);
 758
 759 exit:
 760         kfree(req);
 761         return error;
 762 }
 763
 764 /*
 765     The statements below are part of the Coda opportunistic
 766     programming -- taken from the Mach/BSD kernel code for Coda.
 767     You don't get correct semantics by stating what needs to be
 768     done without guaranteeing the invariants needed for it to happen.
 769     When will be have time to find out what exactly is going on?  (pjb)
 770 */
 771
 772
 773 /*
 774  * There are 7 cases where cache invalidations occur.  The semantics
 775  *  of each is listed here:
 776  *
 777  * CODA_FLUSH     -- flush all entries from the name cache and the cnode cache.
 778  * CODA_PURGEUSER -- flush all entries from the name cache for a specific user
 779  *                  This call is a result of token expiration.
 780  *
 781  * The next arise as the result of callbacks on a file or directory.
 782  * CODA_ZAPFILE   -- flush the cached attributes for a file.
 783
 784  * CODA_ZAPDIR    -- flush the attributes for the dir and
 785  *                  force a new lookup for all the children
 786                     of this dir.
 787
 788  *
 789  * The next is a result of Venus detecting an inconsistent file.
 790  * CODA_PURGEFID  -- flush the attribute for the file
 791  *                  purge it and its children from the dcache
 792  *
 793  * The last  allows Venus to replace local fids with global ones
 794  * during reintegration.
 795  *
 796  * CODA_REPLACE -- replace one CodaFid with another throughout the name cache */
 797
 798 int coda_downcall(int opcode, union outputArgs * out, struct super_block *sb)
 799 {
 800         struct inode *inode = NULL;
 801         struct CodaFid *fid, *newfid;
 802
 803         /* Handle invalidation requests. */
 804         if ( !sb || !sb->s_root)
 805                 return 0;
 806
 807         switch (opcode) {
 808         case CODA_FLUSH:
 809                 coda_cache_clear_all(sb);
 810                 shrink_dcache_sb(sb);
 811                 if (sb->s_root->d_inode)
 812                     coda_flag_inode(sb->s_root->d_inode, C_FLUSH);
 813                 break;
 814
 815         case CODA_PURGEUSER:
 816                 coda_cache_clear_all(sb);
 817                 break;
 818
 819         case CODA_ZAPDIR:
 820                 fid = &out->coda_zapdir.CodaFid;
 821                 inode = coda_fid_to_inode(fid, sb);
 822                 if (inode) {
 823                         coda_flag_inode_children(inode, C_PURGE);
 824                         coda_flag_inode(inode, C_VATTR);
 825                 }
 826                 break;
 827
 828         case CODA_ZAPFILE:
 829                 fid = &out->coda_zapfile.CodaFid;
 830                 inode = coda_fid_to_inode(fid, sb);
 831                 if (inode)
 832                         coda_flag_inode(inode, C_VATTR);
 833                 break;
 834
 835         case CODA_PURGEFID:
 836                 fid = &out->coda_purgefid.CodaFid;
 837                 inode = coda_fid_to_inode(fid, sb);
 838                 if (inode) {
 839                         coda_flag_inode_children(inode, C_PURGE);
 840
 841                         /* catch the dentries later if some are still busy */
 842                         coda_flag_inode(inode, C_PURGE);
 843                         d_prune_aliases(inode);
 844
 845                 }
 846                 break;
 847
 848         case CODA_REPLACE:
 849                 fid = &out->coda_replace.OldFid;
 850                 newfid = &out->coda_replace.NewFid;
 851                 inode = coda_fid_to_inode(fid, sb);
 852                 if (inode)
 853                         coda_replace_fid(inode, fid, newfid);
 854                 break;
 855         }
 856
 857         if (inode)
 858                 iput(inode);
 859
 860         return 0;
 861 }
 862