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 <linux/slab.h>
  30 #include <asm/uaccess.h>
  31 #include <linux/vmalloc.h>
  32 #include <linux/vfs.h>
  33
  34 #include <linux/coda.h>
  35 #include <linux/coda_linux.h>
  36 #include <linux/coda_psdev.h>
  37 #include <linux/coda_fs_i.h>
  38 #include <linux/coda_cache.h>
  39
  40 #include "coda_int.h"
  41
  42 static int coda_upcall(struct venus_comm *vc, int inSize, int *outSize,
  43                        union inputArgs *buffer);
  44
  45 static void *alloc_upcall(int opcode, int size)
  46 {
  47         union inputArgs *inp;
  48
  49         CODA_ALLOC(inp, union inputArgs *, size);
  50         if (!inp)
  51                 return ERR_PTR(-ENOMEM);
  52
  53         inp->ih.opcode = opcode;
  54         inp->ih.pid = current->pid;
  55         inp->ih.pgid = task_pgrp_nr(current);
  56         inp->ih.uid = current_fsuid();
  57
  58         return (void*)inp;
  59 }
  60
  61 #define UPARG(op)\
  62 do {\
  63         inp = (union inputArgs *)alloc_upcall(op, insize); \
  64         if (IS_ERR(inp)) { return PTR_ERR(inp); }\
  65         outp = (union outputArgs *)(inp); \
  66         outsize = insize; \
  67 } while (0)
  68
  69 #define INSIZE(tag) sizeof(struct coda_ ## tag ## _in)
  70 #define OUTSIZE(tag) sizeof(struct coda_ ## tag ## _out)
  71 #define SIZE(tag)  max_t(unsigned int, INSIZE(tag), OUTSIZE(tag))
  72
  73
  74 /* the upcalls */
  75 int venus_rootfid(struct super_block *sb, struct CodaFid *fidp)
  76 {
  77         union inputArgs *inp;
  78         union outputArgs *outp;
  79         int insize, outsize, error;
  80
  81         insize = SIZE(root);
  82         UPARG(CODA_ROOT);
  83
  84         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
  85         if (!error)
  86                 *fidp = outp->coda_root.VFid;
  87
  88         CODA_FREE(inp, insize);
  89         return error;
  90 }
  91
  92 int venus_getattr(struct super_block *sb, struct CodaFid *fid,
  93                      struct coda_vattr *attr)
  94 {
  95         union inputArgs *inp;
  96         union outputArgs *outp;
  97         int insize, outsize, error;
  98
  99         insize = SIZE(getattr);
 100         UPARG(CODA_GETATTR);
 101         inp->coda_getattr.VFid = *fid;
 102
 103         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 104         if (!error)
 105                 *attr = outp->coda_getattr.attr;
 106
 107         CODA_FREE(inp, insize);
 108         return error;
 109 }
 110
 111 int venus_setattr(struct super_block *sb, struct CodaFid *fid,
 112                   struct coda_vattr *vattr)
 113 {
 114         union inputArgs *inp;
 115         union outputArgs *outp;
 116         int insize, outsize, error;
 117
 118         insize = SIZE(setattr);
 119         UPARG(CODA_SETATTR);
 120
 121         inp->coda_setattr.VFid = *fid;
 122         inp->coda_setattr.attr = *vattr;
 123
 124         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 125
 126         CODA_FREE(inp, insize);
 127         return error;
 128 }
 129
 130 int venus_lookup(struct super_block *sb, struct CodaFid *fid,
 131                     const char *name, int length, int * type,
 132                     struct CodaFid *resfid)
 133 {
 134         union inputArgs *inp;
 135         union outputArgs *outp;
 136         int insize, outsize, error;
 137         int offset;
 138
 139         offset = INSIZE(lookup);
 140         insize = max_t(unsigned int, offset + length +1, OUTSIZE(lookup));
 141         UPARG(CODA_LOOKUP);
 142
 143         inp->coda_lookup.VFid = *fid;
 144         inp->coda_lookup.name = offset;
 145         inp->coda_lookup.flags = CLU_CASE_SENSITIVE;
 146         /* send Venus a null terminated string */
 147         memcpy((char *)(inp) + offset, name, length);
 148         *((char *)inp + offset + length) = '\0';
 149
 150         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 151         if (!error) {
 152                 *resfid = outp->coda_lookup.VFid;
 153                 *type = outp->coda_lookup.vtype;
 154         }
 155
 156         CODA_FREE(inp, insize);
 157         return error;
 158 }
 159
 160 int venus_close(struct super_block *sb, struct CodaFid *fid, int flags,
 161                 vuid_t uid)
 162 {
 163         union inputArgs *inp;
 164         union outputArgs *outp;
 165         int insize, outsize, error;
 166
 167         insize = SIZE(release);
 168         UPARG(CODA_CLOSE);
 169
 170         inp->ih.uid = uid;
 171         inp->coda_close.VFid = *fid;
 172         inp->coda_close.flags = flags;
 173
 174         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 175
 176         CODA_FREE(inp, insize);
 177         return error;
 178 }
 179
 180 int venus_open(struct super_block *sb, struct CodaFid *fid,
 181                   int flags, struct file **fh)
 182 {
 183         union inputArgs *inp;
 184         union outputArgs *outp;
 185         int insize, outsize, error;
 186
 187         insize = SIZE(open_by_fd);
 188         UPARG(CODA_OPEN_BY_FD);
 189
 190         inp->coda_open_by_fd.VFid = *fid;
 191         inp->coda_open_by_fd.flags = flags;
 192
 193         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 194         if (!error)
 195                 *fh = outp->coda_open_by_fd.fh;
 196
 197         CODA_FREE(inp, insize);
 198         return error;
 199 }
 200
 201 int venus_mkdir(struct super_block *sb, struct CodaFid *dirfid,
 202                    const char *name, int length,
 203                    struct CodaFid *newfid, struct coda_vattr *attrs)
 204 {
 205         union inputArgs *inp;
 206         union outputArgs *outp;
 207         int insize, outsize, error;
 208         int offset;
 209
 210         offset = INSIZE(mkdir);
 211         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(mkdir));
 212         UPARG(CODA_MKDIR);
 213
 214         inp->coda_mkdir.VFid = *dirfid;
 215         inp->coda_mkdir.attr = *attrs;
 216         inp->coda_mkdir.name = offset;
 217         /* Venus must get null terminated string */
 218         memcpy((char *)(inp) + offset, name, length);
 219         *((char *)inp + offset + length) = '\0';
 220
 221         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 222         if (!error) {
 223                 *attrs = outp->coda_mkdir.attr;
 224                 *newfid = outp->coda_mkdir.VFid;
 225         }
 226
 227         CODA_FREE(inp, insize);
 228         return error;
 229 }
 230
 231
 232 int venus_rename(struct super_block *sb, struct CodaFid *old_fid,
 233                  struct CodaFid *new_fid, size_t old_length,
 234                  size_t new_length, const char *old_name,
 235                  const char *new_name)
 236 {
 237         union inputArgs *inp;
 238         union outputArgs *outp;
 239         int insize, outsize, error;
 240         int offset, s;
 241
 242         offset = INSIZE(rename);
 243         insize = max_t(unsigned int, offset + new_length + old_length + 8,
 244                      OUTSIZE(rename));
 245         UPARG(CODA_RENAME);
 246
 247         inp->coda_rename.sourceFid = *old_fid;
 248         inp->coda_rename.destFid =  *new_fid;
 249         inp->coda_rename.srcname = offset;
 250
 251         /* Venus must receive an null terminated string */
 252         s = ( old_length & ~0x3) +4; /* round up to word boundary */
 253         memcpy((char *)(inp) + offset, old_name, old_length);
 254         *((char *)inp + offset + old_length) = '\0';
 255
 256         /* another null terminated string for Venus */
 257         offset += s;
 258         inp->coda_rename.destname = offset;
 259         s = ( new_length & ~0x3) +4; /* round up to word boundary */
 260         memcpy((char *)(inp) + offset, new_name, new_length);
 261         *((char *)inp + offset + new_length) = '\0';
 262
 263         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 264
 265         CODA_FREE(inp, insize);
 266         return error;
 267 }
 268
 269 int venus_create(struct super_block *sb, struct CodaFid *dirfid,
 270                  const char *name, int length, int excl, int mode,
 271                  struct CodaFid *newfid, struct coda_vattr *attrs)
 272 {
 273         union inputArgs *inp;
 274         union outputArgs *outp;
 275         int insize, outsize, error;
 276         int offset;
 277
 278         offset = INSIZE(create);
 279         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(create));
 280         UPARG(CODA_CREATE);
 281
 282         inp->coda_create.VFid = *dirfid;
 283         inp->coda_create.attr.va_mode = mode;
 284         inp->coda_create.excl = excl;
 285         inp->coda_create.mode = mode;
 286         inp->coda_create.name = offset;
 287
 288         /* Venus must get null terminated string */
 289         memcpy((char *)(inp) + offset, name, length);
 290         *((char *)inp + offset + length) = '\0';
 291
 292         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 293         if (!error) {
 294                 *attrs = outp->coda_create.attr;
 295                 *newfid = outp->coda_create.VFid;
 296         }
 297
 298         CODA_FREE(inp, insize);
 299         return error;
 300 }
 301
 302 int venus_rmdir(struct super_block *sb, struct CodaFid *dirfid,
 303                     const char *name, int length)
 304 {
 305         union inputArgs *inp;
 306         union outputArgs *outp;
 307         int insize, outsize, error;
 308         int offset;
 309
 310         offset = INSIZE(rmdir);
 311         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(rmdir));
 312         UPARG(CODA_RMDIR);
 313
 314         inp->coda_rmdir.VFid = *dirfid;
 315         inp->coda_rmdir.name = offset;
 316         memcpy((char *)(inp) + offset, name, length);
 317         *((char *)inp + offset + length) = '\0';
 318
 319         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 320
 321         CODA_FREE(inp, insize);
 322         return error;
 323 }
 324
 325 int venus_remove(struct super_block *sb, struct CodaFid *dirfid,
 326                     const char *name, int length)
 327 {
 328         union inputArgs *inp;
 329         union outputArgs *outp;
 330         int error=0, insize, outsize, offset;
 331
 332         offset = INSIZE(remove);
 333         insize = max_t(unsigned int, offset + length + 1, OUTSIZE(remove));
 334         UPARG(CODA_REMOVE);
 335
 336         inp->coda_remove.VFid = *dirfid;
 337         inp->coda_remove.name = offset;
 338         memcpy((char *)(inp) + offset, name, length);
 339         *((char *)inp + offset + length) = '\0';
 340
 341         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 342
 343         CODA_FREE(inp, insize);
 344         return error;
 345 }
 346
 347 int venus_readlink(struct super_block *sb, struct CodaFid *fid,
 348                       char *buffer, int *length)
 349 {
 350         union inputArgs *inp;
 351         union outputArgs *outp;
 352         int insize, outsize, error;
 353         int retlen;
 354         char *result;
 355
 356         insize = max_t(unsigned int,
 357                      INSIZE(readlink), OUTSIZE(readlink)+ *length + 1);
 358         UPARG(CODA_READLINK);
 359
 360         inp->coda_readlink.VFid = *fid;
 361
 362         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 363         if (!error) {
 364                 retlen = outp->coda_readlink.count;
 365                 if ( retlen > *length )
 366                         retlen = *length;
 367                 *length = retlen;
 368                 result =  (char *)outp + (long)outp->coda_readlink.data;
 369                 memcpy(buffer, result, retlen);
 370                 *(buffer + retlen) = '\0';
 371         }
 372
 373         CODA_FREE(inp, insize);
 374         return error;
 375 }
 376
 377
 378
 379 int venus_link(struct super_block *sb, struct CodaFid *fid,
 380                   struct CodaFid *dirfid, const char *name, int len )
 381 {
 382         union inputArgs *inp;
 383         union outputArgs *outp;
 384         int insize, outsize, error;
 385         int offset;
 386
 387         offset = INSIZE(link);
 388         insize = max_t(unsigned int, offset  + len + 1, OUTSIZE(link));
 389         UPARG(CODA_LINK);
 390
 391         inp->coda_link.sourceFid = *fid;
 392         inp->coda_link.destFid = *dirfid;
 393         inp->coda_link.tname = offset;
 394
 395         /* make sure strings are null terminated */
 396         memcpy((char *)(inp) + offset, name, len);
 397         *((char *)inp + offset + len) = '\0';
 398
 399         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 400
 401         CODA_FREE(inp, insize);
 402         return error;
 403 }
 404
 405 int venus_symlink(struct super_block *sb, struct CodaFid *fid,
 406                      const char *name, int len,
 407                      const char *symname, int symlen)
 408 {
 409         union inputArgs *inp;
 410         union outputArgs *outp;
 411         int insize, outsize, error;
 412         int offset, s;
 413
 414         offset = INSIZE(symlink);
 415         insize = max_t(unsigned int, offset + len + symlen + 8, OUTSIZE(symlink));
 416         UPARG(CODA_SYMLINK);
 417
 418         /*        inp->coda_symlink.attr = *tva; XXXXXX */
 419         inp->coda_symlink.VFid = *fid;
 420
 421         /* Round up to word boundary and null terminate */
 422         inp->coda_symlink.srcname = offset;
 423         s = ( symlen  & ~0x3 ) + 4;
 424         memcpy((char *)(inp) + offset, symname, symlen);
 425         *((char *)inp + offset + symlen) = '\0';
 426
 427         /* Round up to word boundary and null terminate */
 428         offset += s;
 429         inp->coda_symlink.tname = offset;
 430         s = (len & ~0x3) + 4;
 431         memcpy((char *)(inp) + offset, name, len);
 432         *((char *)inp + offset + len) = '\0';
 433
 434         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 435
 436         CODA_FREE(inp, insize);
 437         return error;
 438 }
 439
 440 int venus_fsync(struct super_block *sb, struct CodaFid *fid)
 441 {
 442         union inputArgs *inp;
 443         union outputArgs *outp;
 444         int insize, outsize, error;
 445
 446         insize=SIZE(fsync);
 447         UPARG(CODA_FSYNC);
 448
 449         inp->coda_fsync.VFid = *fid;
 450         error = coda_upcall(coda_vcp(sb), sizeof(union inputArgs),
 451                             &outsize, inp);
 452
 453         CODA_FREE(inp, insize);
 454         return error;
 455 }
 456
 457 int venus_access(struct super_block *sb, struct CodaFid *fid, int mask)
 458 {
 459         union inputArgs *inp;
 460         union outputArgs *outp;
 461         int insize, outsize, error;
 462
 463         insize = SIZE(access);
 464         UPARG(CODA_ACCESS);
 465
 466         inp->coda_access.VFid = *fid;
 467         inp->coda_access.flags = mask;
 468
 469         error = coda_upcall(coda_vcp(sb), insize, &outsize, inp);
 470
 471         CODA_FREE(inp, insize);
 472         return error;
 473 }
 474
 475
 476 int venus_pioctl(struct super_block *sb, struct CodaFid *fid,
 477                  unsigned int cmd, struct PioctlData *data)
 478 {
 479         union inputArgs *inp;
 480         union outputArgs *outp;
 481         int insize, outsize, error;
 482         int iocsize;
 483
 484         insize = VC_MAXMSGSIZE;
 485         UPARG(CODA_IOCTL);
 486
 487         /* build packet for Venus */
 488         if (data->vi.in_size > VC_MAXDATASIZE) {
 489                 error = -EINVAL;
 490                 goto exit;
 491         }
 492
 493         if (data->vi.out_size > VC_MAXDATASIZE) {
 494                 error = -EINVAL;
 495                 goto exit;
 496         }
 497
 498         inp->coda_ioctl.VFid = *fid;
 499
 500         /* the cmd field was mutated by increasing its size field to
 501          * reflect the path and follow args. We need to subtract that
 502          * out before sending the command to Venus.  */
 503         inp->coda_ioctl.cmd = (cmd & ~(PIOCPARM_MASK << 16));
 504         iocsize = ((cmd >> 16) & PIOCPARM_MASK) - sizeof(char *) - sizeof(int);
 505         inp->coda_ioctl.cmd |= (iocsize & PIOCPARM_MASK) <<     16;
 506
 507         /* in->coda_ioctl.rwflag = flag; */
 508         inp->coda_ioctl.len = data->vi.in_size;
 509         inp->coda_ioctl.data = (char *)(INSIZE(ioctl));
 510
 511         /* get the data out of user space */
 512         if ( copy_from_user((char*)inp + (long)inp->coda_ioctl.data,
 513                             data->vi.in, data->vi.in_size) ) {
 514                 error = -EINVAL;
 515                 goto exit;
 516         }
 517
 518         error = coda_upcall(coda_vcp(sb), SIZE(ioctl) + data->vi.in_size,
 519                             &outsize, inp);
 520
 521         if (error) {
 522                 printk("coda_pioctl: Venus returns: %d for %s\n",
 523                        error, coda_f2s(fid));
 524                 goto exit;
 525         }
 526
 527         if (outsize < (long)outp->coda_ioctl.data + outp->coda_ioctl.len) {
 528                 error = -EINVAL;
 529                 goto exit;
 530         }
 531
 532         /* Copy out the OUT buffer. */
 533         if (outp->coda_ioctl.len > data->vi.out_size) {
 534                 error = -EINVAL;
 535                 goto exit;
 536         }
 537
 538         /* Copy out the OUT buffer. */
 539         if (copy_to_user(data->vi.out,
 540                          (char *)outp + (long)outp->coda_ioctl.data,
 541                          outp->coda_ioctl.len)) {
 542                 error = -EFAULT;
 543                 goto exit;
 544         }
 545
 546  exit:
 547         CODA_FREE(inp, insize);
 548         return error;
 549 }
 550
 551 int venus_statfs(struct dentry *dentry, struct kstatfs *sfs)
 552 {
 553         union inputArgs *inp;
 554         union outputArgs *outp;
 555         int insize, outsize, error;
 556
 557         insize = max_t(unsigned int, INSIZE(statfs), OUTSIZE(statfs));
 558         UPARG(CODA_STATFS);
 559
 560         error = coda_upcall(coda_vcp(dentry->d_sb), insize, &outsize, inp);
 561         if (!error) {
 562                 sfs->f_blocks = outp->coda_statfs.stat.f_blocks;
 563                 sfs->f_bfree  = outp->coda_statfs.stat.f_bfree;
 564                 sfs->f_bavail = outp->coda_statfs.stat.f_bavail;
 565                 sfs->f_files  = outp->coda_statfs.stat.f_files;
 566                 sfs->f_ffree  = outp->coda_statfs.stat.f_ffree;
 567         }
 568
 569         CODA_FREE(inp, insize);
 570         return error;
 571 }
 572
 573 /*
 574  * coda_upcall and coda_downcall routines.
 575  */
 576 static void coda_block_signals(sigset_t *old)
 577 {
 578         spin_lock_irq(&current->sighand->siglock);
 579         *old = current->blocked;
 580
 581         sigfillset(&current->blocked);
 582         sigdelset(&current->blocked, SIGKILL);
 583         sigdelset(&current->blocked, SIGSTOP);
 584         sigdelset(&current->blocked, SIGINT);
 585
 586         recalc_sigpending();
 587         spin_unlock_irq(&current->sighand->siglock);
 588 }
 589
 590 static void coda_unblock_signals(sigset_t *old)
 591 {
 592         spin_lock_irq(&current->sighand->siglock);
 593         current->blocked = *old;
 594         recalc_sigpending();
 595         spin_unlock_irq(&current->sighand->siglock);
 596 }
 597
 598 /* Don't allow signals to interrupt the following upcalls before venus
 599  * has seen them,
 600  * - CODA_CLOSE or CODA_RELEASE upcall  (to avoid reference count problems)
 601  * - CODA_STORE                         (to avoid data loss)
 602  */
 603 #define CODA_INTERRUPTIBLE(r) (!coda_hard && \
 604                                (((r)->uc_opcode != CODA_CLOSE && \
 605                                  (r)->uc_opcode != CODA_STORE && \
 606                                  (r)->uc_opcode != CODA_RELEASE) || \
 607                                 (r)->uc_flags & REQ_READ))
 608
 609 static inline void coda_waitfor_upcall(struct upc_req *req)
 610 {
 611         DECLARE_WAITQUEUE(wait, current);
 612         unsigned long timeout = jiffies + coda_timeout * HZ;
 613         sigset_t old;
 614         int blocked;
 615
 616         coda_block_signals(&old);
 617         blocked = 1;
 618
 619         add_wait_queue(&req->uc_sleep, &wait);
 620         for (;;) {
 621                 if (CODA_INTERRUPTIBLE(req))
 622                         set_current_state(TASK_INTERRUPTIBLE);
 623                 else
 624                         set_current_state(TASK_UNINTERRUPTIBLE);
 625
 626                 /* got a reply */
 627                 if (req->uc_flags & (REQ_WRITE | REQ_ABORT))
 628                         break;
 629
 630                 if (blocked && time_after(jiffies, timeout) &&
 631                     CODA_INTERRUPTIBLE(req))
 632                 {
 633                         coda_unblock_signals(&old);
 634                         blocked = 0;
 635                 }
 636
 637                 if (signal_pending(current)) {
 638                         list_del(&req->uc_chain);
 639                         break;
 640                 }
 641
 642                 if (blocked)
 643                         schedule_timeout(HZ);
 644                 else
 645                         schedule();
 646         }
 647         if (blocked)
 648                 coda_unblock_signals(&old);
 649
 650         remove_wait_queue(&req->uc_sleep, &wait);
 651         set_current_state(TASK_RUNNING);
 652 }
 653
 654
 655 /*
 656  * coda_upcall will return an error in the case of
 657  * failed communication with Venus _or_ will peek at Venus
 658  * reply and return Venus' error.
 659  *
 660  * As venus has 2 types of errors, normal errors (positive) and internal
 661  * errors (negative), normal errors are negated, while internal errors
 662  * are all mapped to -EINTR, while showing a nice warning message. (jh)
 663  */
 664 static int coda_upcall(struct venus_comm *vcp,
 665                        int inSize, int *outSize,
 666                        union inputArgs *buffer)
 667 {
 668         union outputArgs *out;
 669         union inputArgs *sig_inputArgs;
 670         struct upc_req *req, *sig_req;
 671         int error = 0;
 672
 673         if (!vcp->vc_inuse) {
 674                 printk(KERN_NOTICE "coda: Venus dead, not sending upcall\n");
 675                 return -ENXIO;
 676         }
 677
 678         /* Format the request message. */
 679         req = kmalloc(sizeof(struct upc_req), GFP_KERNEL);
 680         if (!req)
 681                 return -ENOMEM;
 682
 683         req->uc_data = (void *)buffer;
 684         req->uc_flags = 0;
 685         req->uc_inSize = inSize;
 686         req->uc_outSize = *outSize ? *outSize : inSize;
 687         req->uc_opcode = ((union inputArgs *)buffer)->ih.opcode;
 688         req->uc_unique = ++vcp->vc_seq;
 689         init_waitqueue_head(&req->uc_sleep);
 690
 691         /* Fill in the common input args. */
 692         ((union inputArgs *)buffer)->ih.unique = req->uc_unique;
 693
 694         /* Append msg to pending queue and poke Venus. */
 695         list_add_tail(&req->uc_chain, &vcp->vc_pending);
 696
 697         wake_up_interruptible(&vcp->vc_waitq);
 698         /* We can be interrupted while we wait for Venus to process
 699          * our request.  If the interrupt occurs before Venus has read
 700          * the request, we dequeue and return. If it occurs after the
 701          * read but before the reply, we dequeue, send a signal
 702          * message, and return. If it occurs after the reply we ignore
 703          * it. In no case do we want to restart the syscall.  If it
 704          * was interrupted by a venus shutdown (psdev_close), return
 705          * ENODEV.  */
 706
 707         /* Go to sleep.  Wake up on signals only after the timeout. */
 708         coda_waitfor_upcall(req);
 709
 710         /* Op went through, interrupt or not... */
 711         if (req->uc_flags & REQ_WRITE) {
 712                 out = (union outputArgs *)req->uc_data;
 713                 /* here we map positive Venus errors to kernel errors */
 714                 error = -out->oh.result;
 715                 *outSize = req->uc_outSize;
 716                 goto exit;
 717         }
 718
 719         error = -EINTR;
 720         if ((req->uc_flags & REQ_ABORT) || !signal_pending(current)) {
 721                 printk(KERN_WARNING "coda: Unexpected interruption.\n");
 722                 goto exit;
 723         }
 724
 725         /* Interrupted before venus read it. */
 726         if (!(req->uc_flags & REQ_READ))
 727                 goto exit;
 728
 729         /* Venus saw the upcall, make sure we can send interrupt signal */
 730         if (!vcp->vc_inuse) {
 731                 printk(KERN_INFO "coda: Venus dead, not sending signal.\n");
 732                 goto exit;
 733         }
 734
 735         error = -ENOMEM;
 736         sig_req = kmalloc(sizeof(struct upc_req), GFP_KERNEL);
 737         if (!sig_req) goto exit;
 738
 739         CODA_ALLOC((sig_req->uc_data), char *, sizeof(struct coda_in_hdr));
 740         if (!sig_req->uc_data) {
 741                 kfree(sig_req);
 742                 goto exit;
 743         }
 744
 745         error = -EINTR;
 746         sig_inputArgs = (union inputArgs *)sig_req->uc_data;
 747         sig_inputArgs->ih.opcode = CODA_SIGNAL;
 748         sig_inputArgs->ih.unique = req->uc_unique;
 749
 750         sig_req->uc_flags = REQ_ASYNC;
 751         sig_req->uc_opcode = sig_inputArgs->ih.opcode;
 752         sig_req->uc_unique = sig_inputArgs->ih.unique;
 753         sig_req->uc_inSize = sizeof(struct coda_in_hdr);
 754         sig_req->uc_outSize = sizeof(struct coda_in_hdr);
 755
 756         /* insert at head of queue! */
 757         list_add(&(sig_req->uc_chain), &vcp->vc_pending);
 758         wake_up_interruptible(&vcp->vc_waitq);
 759
 760 exit:
 761         kfree(req);
 762         return error;
 763 }
 764
 765 /*
 766     The statements below are part of the Coda opportunistic
 767     programming -- taken from the Mach/BSD kernel code for Coda.
 768     You don't get correct semantics by stating what needs to be
 769     done without guaranteeing the invariants needed for it to happen.
 770     When will be have time to find out what exactly is going on?  (pjb)
 771 */
 772
 773
 774 /*
 775  * There are 7 cases where cache invalidations occur.  The semantics
 776  *  of each is listed here:
 777  *
 778  * CODA_FLUSH     -- flush all entries from the name cache and the cnode cache.
 779  * CODA_PURGEUSER -- flush all entries from the name cache for a specific user
 780  *                  This call is a result of token expiration.
 781  *
 782  * The next arise as the result of callbacks on a file or directory.
 783  * CODA_ZAPFILE   -- flush the cached attributes for a file.
 784
 785  * CODA_ZAPDIR    -- flush the attributes for the dir and
 786  *                  force a new lookup for all the children
 787                     of this dir.
 788
 789  *
 790  * The next is a result of Venus detecting an inconsistent file.
 791  * CODA_PURGEFID  -- flush the attribute for the file
 792  *                  purge it and its children from the dcache
 793  *
 794  * The last  allows Venus to replace local fids with global ones
 795  * during reintegration.
 796  *
 797  * CODA_REPLACE -- replace one CodaFid with another throughout the name cache */
 798
 799 int coda_downcall(int opcode, union outputArgs * out, struct super_block *sb)
 800 {
 801         struct inode *inode = NULL;
 802         struct CodaFid *fid, *newfid;
 803
 804         /* Handle invalidation requests. */
 805         if ( !sb || !sb->s_root)
 806                 return 0;
 807
 808         switch (opcode) {
 809         case CODA_FLUSH:
 810                 coda_cache_clear_all(sb);
 811                 shrink_dcache_sb(sb);
 812                 if (sb->s_root->d_inode)
 813                     coda_flag_inode(sb->s_root->d_inode, C_FLUSH);
 814                 break;
 815
 816         case CODA_PURGEUSER:
 817                 coda_cache_clear_all(sb);
 818                 break;
 819
 820         case CODA_ZAPDIR:
 821                 fid = &out->coda_zapdir.CodaFid;
 822                 inode = coda_fid_to_inode(fid, sb);
 823                 if (inode) {
 824                         coda_flag_inode_children(inode, C_PURGE);
 825                         coda_flag_inode(inode, C_VATTR);
 826                 }
 827                 break;
 828
 829         case CODA_ZAPFILE:
 830                 fid = &out->coda_zapfile.CodaFid;
 831                 inode = coda_fid_to_inode(fid, sb);
 832                 if (inode)
 833                         coda_flag_inode(inode, C_VATTR);
 834                 break;
 835
 836         case CODA_PURGEFID:
 837                 fid = &out->coda_purgefid.CodaFid;
 838                 inode = coda_fid_to_inode(fid, sb);
 839                 if (inode) {
 840                         coda_flag_inode_children(inode, C_PURGE);
 841
 842                         /* catch the dentries later if some are still busy */
 843                         coda_flag_inode(inode, C_PURGE);
 844                         d_prune_aliases(inode);
 845
 846                 }
 847                 break;
 848
 849         case CODA_REPLACE:
 850                 fid = &out->coda_replace.OldFid;
 851                 newfid = &out->coda_replace.NewFid;
 852                 inode = coda_fid_to_inode(fid, sb);
 853                 if (inode)
 854                         coda_replace_fid(inode, fid, newfid);
 855                 break;
 856         }
 857
 858         if (inode)
 859                 iput(inode);
 860
 861         return 0;
 862 }
 863