src/vol/vutil.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 /*
  11         System:         VICE-TWO
  12         Module:         vutil.c
  13         Institution:    The Information Technology Center, Carnegie-Mellon University
  14
  15  */
  16
  17 #include <afsconfig.h>
  18 #include <afs/param.h>
  19
  20 #include <roken.h>
  21 #include <afs/opr.h>
  22
  23 #ifdef HAVE_SYS_FILE_H
  24 #include <sys/file.h>
  25 #endif
  26
  27 #ifdef HAVE_SYS_LOCKF_H
  28 #include <sys/lockf.h>
  29 #endif
  30
  31 #ifdef AFS_PTHREAD_ENV
  32 # include <opr/lock.h>
  33 #else
  34 # include <opr/lockstub.h>
  35 #endif
  36
  37 #include <rx/rx_queue.h>
  38 #include <rx/xdr.h>
  39 #include <afs/afsint.h>
  40 #include "nfs.h"
  41 #include <afs/errors.h>
  42 #include "lock.h"
  43 #include "lwp.h"
  44 #include <afs/afssyscalls.h>
  45 #include "ihandle.h"
  46 #include <afs/afsutil.h>
  47 #ifdef AFS_NT40_ENV
  48 #include "ntops.h"
  49 #endif
  50 #include "vnode.h"
  51 #include "volume.h"
  52 #include "volume_inline.h"
  53 #include "partition.h"
  54 #include "viceinode.h"
  55
  56 #include "volinodes.h"
  57 #include "vol_prototypes.h"
  58 #include "common.h"
  59
  60 #ifndef AFS_NT40_ENV
  61 # ifdef O_LARGEFILE
  62 #  define AFS_SETLKW   F_SETLKW64
  63 #  define AFS_SETLK    F_SETLK64
  64 #  define afs_st_flock flock64
  65 # else
  66 #  define AFS_SETLKW   F_SETLKW
  67 #  define AFS_SETLK    F_SETLK
  68 #  define afs_st_flock flock
  69 # endif
  70 #endif
  71
  72 /* Note:  the volume creation functions herein leave the destroyMe flag in the
  73    volume header ON:  this means that the volumes will not be attached by the
  74    file server and WILL BE DESTROYED the next time a system salvage is performed */
  75
  76 #ifdef FSSYNC_BUILD_CLIENT
  77 static void
  78 RemoveInodes(struct afs_inode_info *stuff, Device dev, VolumeId parent,
  79              VolumeId vid)
  80 {
  81     int i;
  82     IHandle_t *handle;
  83
  84     /* This relies on the fact that IDEC only needs the device and NT only
  85      * needs the dev and vid to decrement volume special files.
  86      */
  87     IH_INIT(handle, dev, parent, -1);
  88     for (i = 0; i < MAXINODETYPE; i++) {
  89         Inode inode = *stuff[i].inode;
  90         if (VALID_INO(inode)) {
  91             if (stuff[i].inodeType == VI_LINKTABLE) {
  92                 IH_DEC(handle, inode, parent);
  93             } else {
  94                 IH_DEC(handle, inode, vid);
  95             }
  96         }
  97     }
  98     IH_RELEASE(handle);
  99 }
 100
 101 Volume *
 102 VCreateVolume(Error * ec, char *partname, VolumeId volumeId, VolumeId parentId)
 103 {                               /* Should be the same as volumeId if there is
 104                                  * no parent */
 105     Volume *retVal;
 106     VOL_LOCK;
 107     retVal = VCreateVolume_r(ec, partname, volumeId, parentId);
 108     VOL_UNLOCK;
 109     return retVal;
 110 }
 111
 112 Volume *
 113 VCreateVolume_r(Error * ec, char *partname, VolumeId volumeId, VolumeId parentId)
 114 {                               /* Should be the same as volumeId if there is
 115                                  * no parent */
 116     VolumeDiskData vol;
 117     int i, rc;
 118     char headerName[VMAXPATHLEN], volumePath[VMAXPATHLEN];
 119     Device device;
 120     struct DiskPartition64 *partition;
 121     struct VolumeDiskHeader diskHeader;
 122     IHandle_t *handle;
 123     FdHandle_t *fdP;
 124     Inode nearInode AFS_UNUSED = 0;
 125     char *part, *name;
 126     struct stat st;
 127     struct VolumeHeader tempHeader;
 128     struct afs_inode_info stuff[MAXINODETYPE];
 129     afs_ino_str_t stmp;
 130 # ifdef AFS_DEMAND_ATTACH_FS
 131     int locktype = 0;
 132 # endif /* AFS_DEMAND_ATTACH_FS */
 133
 134     init_inode_info(&tempHeader, stuff);
 135
 136     *ec = 0;
 137     memset(&vol, 0, sizeof(vol));
 138     vol.id = volumeId;
 139     vol.parentId = parentId;
 140     vol.copyDate = time(0);     /* The only date which really means when this
 141                                  * @i(instance) of this volume was created.
 142                                  * Creation date does not mean this */
 143
 144     /* Initialize handle for error case below. */
 145     handle = NULL;
 146
 147     /* Verify that the parition is valid before writing to it. */
 148     if (!(partition = VGetPartition_r(partname, 0))) {
 149         Log("VCreateVolume: partition %s is not in service.\n", partname);
 150         *ec = VNOVOL;
 151         return NULL;
 152     }
 153 #if     defined(NEARINODE_HINT)
 154     nearInodeHash(volumeId, nearInode);
 155     nearInode %= partition->f_files;
 156 #endif
 157     VGetVolumePath(ec, vol.id, &part, &name);
 158     if (*ec == VNOVOL || !strcmp(partition->name, part)) {
 159         /* this case is ok */
 160     } else {
 161         /* return EXDEV if it's a clone or read-only to an alternate partition
 162          * otherwise assume it's a move */
 163         if (vol.parentId != vol.id) {
 164             Log("VCreateVolume: volume %" AFS_VOLID_FMT " for parent %" AFS_VOLID_FMT
 165                 " found on %s; unable to create volume on %s.\n",
 166                 afs_printable_VolumeId_lu(vol.id),
 167                 afs_printable_VolumeId_lu(vol.parentId), part, partition->name);
 168             *ec = EXDEV;
 169             return NULL;
 170         }
 171     }
 172     *ec = 0;
 173
 174 # ifdef AFS_DEMAND_ATTACH_FS
 175     /* volume doesn't exist yet, but we must lock it to try to prevent something
 176      * else from reading it when we're e.g. half way through creating it (or
 177      * something tries to create the same volume at the same time) */
 178     locktype = VVolLockType(V_VOLUPD, 1);
 179     rc = VLockVolumeByIdNB(volumeId, partition, locktype);
 180     if (rc) {
 181         Log("VCreateVolume: vol %lu already locked by someone else\n",
 182             afs_printable_uint32_lu(volumeId));
 183         *ec = VNOVOL;
 184         return NULL;
 185     }
 186 # else /* AFS_DEMAND_ATTACH_FS */
 187     VLockPartition_r(partname);
 188 # endif /* !AFS_DEMAND_ATTACH_FS */
 189
 190     memset(&tempHeader, 0, sizeof(tempHeader));
 191     tempHeader.stamp.magic = VOLUMEHEADERMAGIC;
 192     tempHeader.stamp.version = VOLUMEHEADERVERSION;
 193     tempHeader.id = vol.id;
 194     tempHeader.parent = vol.parentId;
 195     vol.stamp.magic = VOLUMEINFOMAGIC;
 196     vol.stamp.version = VOLUMEINFOVERSION;
 197     vol.destroyMe = DESTROY_ME;
 198     snprintf(headerName, sizeof headerName, VFORMAT,
 199              afs_printable_VolumeId_lu(vol.id));
 200     snprintf(volumePath, sizeof volumePath, "%s" OS_DIRSEP "%s",
 201              VPartitionPath(partition), headerName);
 202     rc = stat(volumePath, &st);
 203     if (rc == 0 || errno != ENOENT) {
 204         if (rc == 0) {
 205             Log("VCreateVolume: Header file %s already exists!\n",
 206                 volumePath);
 207             *ec = VVOLEXISTS;
 208         } else {
 209             Log("VCreateVolume: Error %d trying to stat header file %s\n",
 210                 errno, volumePath);
 211             *ec = VNOVOL;
 212         }
 213         goto bad_noheader;
 214     }
 215     device = partition->device;
 216
 217     for (i = 0; i < MAXINODETYPE; i++) {
 218         struct afs_inode_info *p = &stuff[i];
 219         if (p->obsolete)
 220             continue;
 221 #ifdef AFS_NAMEI_ENV
 222         *(p->inode) =
 223             IH_CREATE(NULL, device, VPartitionPath(partition), nearInode,
 224                       (p->inodeType == VI_LINKTABLE) ? vol.parentId : vol.id,
 225                       INODESPECIAL, p->inodeType, vol.parentId);
 226         if (!(VALID_INO(*(p->inode)))) {
 227             if (errno == EEXIST && (p->inodeType == VI_LINKTABLE)) {
 228                 /* Increment the reference count instead. */
 229                 IHandle_t *lh;
 230                 int code;
 231
 232                 *(p->inode) = namei_MakeSpecIno(vol.parentId, VI_LINKTABLE);
 233                 IH_INIT(lh, device, parentId, *(p->inode));
 234                 fdP = IH_OPEN(lh);
 235                 if (fdP == NULL) {
 236                     IH_RELEASE(lh);
 237                     goto bad;
 238                 }
 239                 code = IH_INC(lh, *(p->inode), parentId);
 240                 FDH_REALLYCLOSE(fdP);
 241                 IH_RELEASE(lh);
 242                 if (code < 0)
 243                     goto bad;
 244                 continue;
 245             }
 246         }
 247 #else
 248         *(p->inode) =
 249             IH_CREATE(NULL, device, VPartitionPath(partition), nearInode,
 250                       vol.id, INODESPECIAL, p->inodeType, vol.parentId);
 251 #endif
 252
 253         if (!VALID_INO(*(p->inode))) {
 254             Log("VCreateVolume:  Problem creating %s file associated with volume header %s\n", p->description, volumePath);
 255           bad:
 256             if (handle)
 257                 IH_RELEASE(handle);
 258             RemoveInodes(stuff, device, vol.parentId, vol.id);
 259             if (!*ec) {
 260                 *ec = VNOVOL;
 261             }
 262             VDestroyVolumeDiskHeader(partition, volumeId, parentId);
 263           bad_noheader:
 264 # ifdef AFS_DEMAND_ATTACH_FS
 265             if (locktype) {
 266                 VUnlockVolumeById(volumeId, partition);
 267             }
 268 # endif /* AFS_DEMAND_ATTACH_FS */
 269             return NULL;
 270         }
 271         IH_INIT(handle, device, vol.parentId, *(p->inode));
 272         fdP = IH_OPEN(handle);
 273         if (fdP == NULL) {
 274             Log("VCreateVolume:  Problem iopen inode %s (err=%d)\n",
 275                 PrintInode(stmp, *(p->inode)), errno);
 276             goto bad;
 277         }
 278         if (FDH_PWRITE(fdP, (char *)&p->stamp, sizeof(p->stamp), 0) !=
 279             sizeof(p->stamp)) {
 280             Log("VCreateVolume:  Problem writing to inode %s (err=%d)\n",
 281                 PrintInode(stmp, *(p->inode)), errno);
 282             FDH_REALLYCLOSE(fdP);
 283             goto bad;
 284         }
 285         FDH_REALLYCLOSE(fdP);
 286         IH_RELEASE(handle);
 287         nearInode = *(p->inode);
 288     }
 289
 290     IH_INIT(handle, device, vol.parentId, tempHeader.volumeInfo);
 291     fdP = IH_OPEN(handle);
 292     if (fdP == NULL) {
 293         Log("VCreateVolume:  Problem iopen inode %s (err=%d)\n",
 294             PrintInode(stmp, tempHeader.volumeInfo), errno);
 295         goto bad;
 296     }
 297     if (FDH_PWRITE(fdP, (char *)&vol, sizeof(vol), 0) != sizeof(vol)) {
 298         Log("VCreateVolume:  Problem writing to  inode %s (err=%d)\n",
 299             PrintInode(stmp, tempHeader.volumeInfo), errno);
 300         FDH_REALLYCLOSE(fdP);
 301         goto bad;
 302     }
 303     FDH_CLOSE(fdP);
 304     IH_RELEASE(handle);
 305
 306     VolumeHeaderToDisk(&diskHeader, &tempHeader);
 307     rc = VCreateVolumeDiskHeader(&diskHeader, partition);
 308     if (rc) {
 309         Log("VCreateVolume: Error %d trying to write volume header for "
 310             "volume %" AFS_VOLID_FMT " on partition %s; volume not created\n", rc,
 311             afs_printable_VolumeId_lu(vol.id), VPartitionPath(partition));
 312         if (rc == EEXIST) {
 313             *ec = VVOLEXISTS;
 314         }
 315         goto bad;
 316     }
 317
 318 # ifdef AFS_DEMAND_ATTACH_FS
 319     if (locktype) {
 320         VUnlockVolumeById(volumeId, partition);
 321     }
 322 # endif /* AFS_DEMAND_ATTACH_FS */
 323     return (VAttachVolumeByName_r(ec, partname, headerName, V_SECRETLY));
 324 }
 325 #endif /* FSSYNC_BUILD_CLIENT */
 326
 327
 328 void
 329 AssignVolumeName(VolumeDiskData * vol, char *name, char *ext)
 330 {
 331     VOL_LOCK;
 332     AssignVolumeName_r(vol, name, ext);
 333     VOL_UNLOCK;
 334 }
 335
 336 void
 337 AssignVolumeName_r(VolumeDiskData * vol, char *name, char *ext)
 338 {
 339     char *dot;
 340     strncpy(vol->name, name, VNAMESIZE - 1);
 341     vol->name[VNAMESIZE - 1] = '\0';
 342     dot = strrchr(vol->name, '.');
 343     if (dot && (strcmp(dot, ".backup") == 0 || strcmp(dot, ".readonly") == 0))
 344         *dot = 0;
 345     if (ext)
 346         strncat(vol->name, ext, VNAMESIZE - 1 - strlen(vol->name));
 347 }
 348
 349 afs_int32
 350 CopyVolumeHeader_r(VolumeDiskData * from, VolumeDiskData * to)
 351 {
 352     /* The id and parentId fields are not copied; these are inviolate--the to volume
 353      * is assumed to have already been created.  The id's cannot be changed once
 354      * creation has taken place, since they are embedded in the various inodes associated
 355      * with the volume.  The copydate is also inviolate--it always reflects the time
 356      * this volume was created (compare with the creation date--the creation date of
 357      * a backup volume is the creation date of the original parent, because the backup
 358      * is used to backup the parent volume). */
 359     Date copydate;
 360     VolumeId id, parent;
 361     id = to->id;
 362     parent = to->parentId;
 363     copydate = to->copyDate;
 364     memcpy(to, from, sizeof(*from));
 365     to->id = id;
 366     to->parentId = parent;
 367     to->copyDate = copydate;
 368     to->destroyMe = DESTROY_ME; /* Caller must always clear this!!! */
 369     to->stamp.magic = VOLUMEINFOMAGIC;
 370     to->stamp.version = VOLUMEINFOVERSION;
 371     return 0;
 372 }
 373
 374 afs_int32
 375 CopyVolumeHeader(VolumeDiskData * from, VolumeDiskData * to)
 376 {
 377     afs_int32 code;
 378
 379     VOL_LOCK;
 380     code = CopyVolumeHeader_r(from, to);
 381     VOL_UNLOCK;
 382     return (code);
 383 }
 384
 385 void
 386 ClearVolumeStats(VolumeDiskData * vol)
 387 {
 388     VOL_LOCK;
 389     ClearVolumeStats_r(vol);
 390     VOL_UNLOCK;
 391 }
 392
 393 void
 394 ClearVolumeStats_r(VolumeDiskData * vol)
 395 {
 396     memset(vol->weekUse, 0, sizeof(vol->weekUse));
 397     vol->dayUse = 0;
 398     vol->dayUseDate = 0;
 399 }
 400
 401 void
 402 CopyVolumeStats_r(VolumeDiskData * from, VolumeDiskData * to)
 403 {
 404     memcpy(to->weekUse, from->weekUse, sizeof(to->weekUse));
 405     to->dayUse = from->dayUse;
 406     to->dayUseDate = from->dayUseDate;
 407     if (from->stat_initialized) {
 408         memcpy(to->stat_reads, from->stat_reads, sizeof(to->stat_reads));
 409         memcpy(to->stat_writes, from->stat_writes, sizeof(to->stat_writes));
 410         memcpy(to->stat_fileSameAuthor, from->stat_fileSameAuthor,
 411                sizeof(to->stat_fileSameAuthor));
 412         memcpy(to->stat_fileDiffAuthor, from->stat_fileDiffAuthor,
 413                sizeof(to->stat_fileDiffAuthor));
 414         memcpy(to->stat_dirSameAuthor, from->stat_dirSameAuthor,
 415                sizeof(to->stat_dirSameAuthor));
 416         memcpy(to->stat_dirDiffAuthor, from->stat_dirDiffAuthor,
 417                sizeof(to->stat_dirDiffAuthor));
 418     }
 419 }
 420
 421 void
 422 CopyVolumeStats(VolumeDiskData * from, VolumeDiskData * to)
 423 {
 424     VOL_LOCK;
 425     CopyVolumeStats_r(from, to);
 426     VOL_UNLOCK;
 427 }
 428
 429 /**
 430  * read an existing volume disk header.
 431  *
 432  * @param[in]  volid  volume id
 433  * @param[in]  dp     disk partition object
 434  * @param[out] hdr    volume disk header or NULL
 435  *
 436  * @note if hdr is NULL, this is essentially an existence test for the vol
 437  *       header
 438  *
 439  * @return operation status
 440  *    @retval 0 success
 441  *    @retval -1 volume header doesn't exist
 442  *    @retval EIO failed to read volume header
 443  *
 444  * @internal
 445  */
 446 afs_int32
 447 VReadVolumeDiskHeader(VolumeId volid,
 448                       struct DiskPartition64 * dp,
 449                       VolumeDiskHeader_t * hdr)
 450 {
 451     afs_int32 code = 0;
 452     int fd;
 453     char path[MAXPATHLEN];
 454
 455     snprintf(path, sizeof(path), "%s" OS_DIRSEP VFORMAT,
 456              VPartitionPath(dp), afs_printable_VolumeId_lu(volid));
 457     fd = open(path, O_RDONLY);
 458     if (fd < 0) {
 459         Log("VReadVolumeDiskHeader: Couldn't open header for volume %" AFS_VOLID_FMT " (errno %d).\n",
 460             afs_printable_VolumeId_lu(volid), errno);
 461         code = -1;
 462
 463     } else if (hdr && read(fd, hdr, sizeof(*hdr)) != sizeof(*hdr)) {
 464         Log("VReadVolumeDiskHeader: Couldn't read header for volume %" AFS_VOLID_FMT ".\n",
 465             afs_printable_VolumeId_lu(volid));
 466         code = EIO;
 467     }
 468
 469     if (fd >= 0) {
 470         close(fd);
 471     }
 472     return code;
 473 }
 474
 475 #ifdef FSSYNC_BUILD_CLIENT
 476 /**
 477  * write an existing volume disk header.
 478  *
 479  * @param[in] hdr   volume disk header
 480  * @param[in] dp    disk partition object
 481  * @param[in] cr    assert if O_CREAT | O_EXCL should be passed to open()
 482  *
 483  * @return operation status
 484  *    @retval 0 success
 485  *    @retval -1 volume header doesn't exist
 486  *    @retval EIO failed to write volume header
 487  *
 488  * @internal
 489  */
 490 static afs_int32
 491 _VWriteVolumeDiskHeader(VolumeDiskHeader_t * hdr,
 492                         struct DiskPartition64 * dp,
 493                         int flags)
 494 {
 495     afs_int32 code = 0;
 496     int fd;
 497     char path[MAXPATHLEN];
 498
 499 #ifdef AFS_DEMAND_ATTACH_FS
 500     /* prevent racing with VGC scanners reading the vol header while we are
 501      * writing it */
 502     code = VPartHeaderLock(dp, READ_LOCK);
 503     if (code) {
 504         return EIO;
 505     }
 506 #endif /* AFS_DEMAND_ATTACH_FS */
 507
 508     flags |= O_RDWR;
 509
 510     snprintf(path, sizeof(path), "%s" OS_DIRSEP VFORMAT,
 511              VPartitionPath(dp), afs_printable_VolumeId_lu(hdr->id));
 512     fd = open(path, flags, 0644);
 513     if (fd < 0) {
 514         code = errno;
 515         Log("_VWriteVolumeDiskHeader: Couldn't open header for volume %lu, "
 516             "error = %d\n", afs_printable_uint32_lu(hdr->id), errno);
 517     } else if (write(fd, hdr, sizeof(*hdr)) != sizeof(*hdr)) {
 518         Log("_VWriteVolumeDiskHeader: Couldn't write header for volume %lu, "
 519             "error = %d\n", afs_printable_uint32_lu(hdr->id), errno);
 520         code = EIO;
 521     }
 522
 523     if (fd >= 0) {
 524         if (close(fd) != 0) {
 525             Log("_VWriteVolumeDiskHeader: Error closing header for volume "
 526                 "%lu, errno %d\n", afs_printable_uint32_lu(hdr->id), errno);
 527         }
 528     }
 529
 530 #ifdef AFS_DEMAND_ATTACH_FS
 531     VPartHeaderUnlock(dp, READ_LOCK);
 532 #endif /* AFS_DEMAND_ATTACH_FS */
 533
 534     return code;
 535 }
 536
 537 /**
 538  * write an existing volume disk header.
 539  *
 540  * @param[in] hdr   volume disk header
 541  * @param[in] dp    disk partition object
 542  *
 543  * @return operation status
 544  *    @retval 0 success
 545  *    @retval ENOENT volume header doesn't exist
 546  *    @retval EIO failed to write volume header
 547  */
 548 afs_int32
 549 VWriteVolumeDiskHeader(VolumeDiskHeader_t * hdr,
 550                        struct DiskPartition64 * dp)
 551 {
 552     afs_int32 code;
 553
 554 #ifdef AFS_DEMAND_ATTACH_FS
 555     VolumeDiskHeader_t oldhdr;
 556     int delvgc = 0, addvgc = 0;
 557     SYNC_response res;
 558
 559     /* first, see if anything with the volume IDs have changed; if so, we
 560      * need to update the VGC */
 561
 562     code = VReadVolumeDiskHeader(hdr->id, dp, &oldhdr);
 563     if (code == 0 && (oldhdr.id != hdr->id || oldhdr.parent != hdr->parent)) {
 564         /* the vol id or parent vol id changed; need to delete the VGC entry
 565          * for the old vol id/parent, and add the new one */
 566         delvgc = 1;
 567         addvgc = 1;
 568
 569     } else if (code) {
 570         /* couldn't get the old header info; add the new header info to the
 571          * VGC in case it hasn't been added yet */
 572         addvgc = 1;
 573     }
 574
 575 #endif /* AFS_DEMAND_ATTACH_FS */
 576
 577     code = _VWriteVolumeDiskHeader(hdr, dp, 0);
 578     if (code) {
 579         goto done;
 580     }
 581
 582 #ifdef AFS_DEMAND_ATTACH_FS
 583     if (delvgc) {
 584         memset(&res, 0, sizeof(res));
 585         code = FSYNC_VGCDel(dp->name, oldhdr.parent, oldhdr.id, FSYNC_WHATEVER, &res);
 586
 587         /* unknown vol id is okay; it just further suggests the old header
 588          * data was bogus, which is fine since we're trying to fix it */
 589         if (code && res.hdr.reason != FSYNC_UNKNOWN_VOLID) {
 590             Log("VWriteVolumeDiskHeader: FSYNC_VGCDel(%s, %lu, %lu) "
 591                 "failed with code %ld reason %ld\n", dp->name,
 592                 afs_printable_uint32_lu(oldhdr.parent),
 593                 afs_printable_uint32_lu(oldhdr.id),
 594                 afs_printable_int32_ld(code),
 595                 afs_printable_int32_ld(res.hdr.reason));
 596         }
 597
 598     }
 599     if (addvgc) {
 600         memset(&res, 0, sizeof(res));
 601         code = FSYNC_VGCAdd(dp->name, hdr->parent, hdr->id, FSYNC_WHATEVER, &res);
 602         if (code) {
 603             Log("VWriteVolumeDiskHeader: FSYNC_VGCAdd(%s, %lu, %lu) "
 604                 "failed with code %ld reason %ld\n", dp->name,
 605                 afs_printable_uint32_lu(hdr->parent),
 606                 afs_printable_uint32_lu(hdr->id),
 607                 afs_printable_int32_ld(code),
 608                 afs_printable_int32_ld(res.hdr.reason));
 609         }
 610     }
 611
 612 #endif /* AFS_DEMAND_ATTACH_FS */
 613
 614  done:
 615     return code;
 616 }
 617
 618 /**
 619  * create and write a volume disk header to disk.
 620  *
 621  * @param[in] hdr   volume disk header
 622  * @param[in] dp    disk partition object
 623  *
 624  * @return operation status
 625  *    @retval 0 success
 626  *    @retval EEXIST volume header already exists
 627  *    @retval EIO failed to write volume header
 628  *
 629  * @internal
 630  */
 631 afs_int32
 632 VCreateVolumeDiskHeader(VolumeDiskHeader_t * hdr,
 633                         struct DiskPartition64 * dp)
 634 {
 635     afs_int32 code = 0;
 636 #ifdef AFS_DEMAND_ATTACH_FS
 637     SYNC_response res;
 638 #endif /* AFS_DEMAND_ATTACH_FS */
 639
 640     code = _VWriteVolumeDiskHeader(hdr, dp, O_CREAT | O_EXCL);
 641     if (code) {
 642         goto done;
 643     }
 644
 645 #ifdef AFS_DEMAND_ATTACH_FS
 646     memset(&res, 0, sizeof(res));
 647     code = FSYNC_VGCAdd(dp->name, hdr->parent, hdr->id, FSYNC_WHATEVER, &res);
 648     if (code) {
 649         Log("VCreateVolumeDiskHeader: FSYNC_VGCAdd(%s, %lu, %lu) failed "
 650             "with code %ld reason %ld\n", dp->name,
 651             afs_printable_uint32_lu(hdr->parent),
 652             afs_printable_uint32_lu(hdr->id),
 653             afs_printable_int32_ld(code),
 654             afs_printable_int32_ld(res.hdr.reason));
 655     }
 656 #endif /* AFS_DEMAND_ATTACH_FS */
 657
 658  done:
 659     return code;
 660 }
 661
 662
 663 /**
 664  * destroy a volume disk header.
 665  *
 666  * @param[in] dp      disk partition object
 667  * @param[in] volid   volume id
 668  * @param[in] parent  parent's volume id, 0 if unknown
 669  *
 670  * @return operation status
 671  *    @retval 0 success
 672  *
 673  * @note if parent is 0, the parent volume ID will be looked up from the
 674  * fileserver
 675  *
 676  * @note for non-DAFS, parent is currently ignored
 677  */
 678 afs_int32
 679 VDestroyVolumeDiskHeader(struct DiskPartition64 * dp,
 680                          VolumeId volid,
 681                          VolumeId parent)
 682 {
 683     afs_int32 code = 0;
 684     char path[MAXPATHLEN];
 685 #ifdef AFS_DEMAND_ATTACH_FS
 686     SYNC_response res;
 687 #endif /* AFS_DEMAND_ATTACH_FS */
 688
 689     snprintf(path, sizeof(path), "%s" OS_DIRSEP VFORMAT,
 690              VPartitionPath(dp), afs_printable_VolumeId_lu(volid));
 691     code = unlink(path);
 692     if (code) {
 693         Log("VDestroyVolumeDiskHeader: Couldn't unlink disk header, error = %d\n", errno);
 694         goto done;
 695     }
 696
 697 #ifdef AFS_DEMAND_ATTACH_FS
 698     memset(&res, 0, sizeof(res));
 699     if (!parent) {
 700         FSSYNC_VGQry_response_t q_res;
 701
 702         code = FSYNC_VGCQuery(dp->name, volid, &q_res, &res);
 703         if (code) {
 704             Log("VDestroyVolumeDiskHeader: FSYNC_VGCQuery(%s, %lu) failed "
 705                 "with code %ld, reason %ld\n", dp->name,
 706                 afs_printable_uint32_lu(volid), afs_printable_int32_ld(code),
 707                 afs_printable_int32_ld(res.hdr.reason));
 708             goto done;
 709         }
 710
 711         parent = q_res.rw;
 712
 713     }
 714     code = FSYNC_VGCDel(dp->name, parent, volid, FSYNC_WHATEVER, &res);
 715     if (code) {
 716         Log("VDestroyVolumeDiskHeader: FSYNC_VGCDel(%s, %" AFS_VOLID_FMT ", %" AFS_VOLID_FMT ") failed "
 717             "with code %ld reason %ld\n", dp->name,
 718             afs_printable_VolumeId_lu(parent),
 719             afs_printable_VolumeId_lu(volid),
 720             afs_printable_int32_ld(code),
 721             afs_printable_int32_ld(res.hdr.reason));
 722     }
 723 #endif /* AFS_DEMAND_ATTACH_FS */
 724
 725  done:
 726     return code;
 727 }
 728 #endif /* FSSYNC_BUILD_CLIENT */
 729
 730 /**
 731  * handle a single vol header as part of VWalkVolumeHeaders.
 732  *
 733  * @param[in] dp      disk partition
 734  * @param[in] volfunc function to call when a vol header is successfully read
 735  * @param[in] name    full path name to the .vol header
 736  * @param[out] hdr    header data read in from the .vol header
 737  * @param[in] locked  1 if the partition headers are locked, 0 otherwise
 738  * @param[in] rock    the rock to pass to volfunc
 739  *
 740  * @return operation status
 741  *  @retval 0  success
 742  *  @retval -1 fatal error, stop scanning
 743  *  @retval 1  failed to read header
 744  *  @retval 2  volfunc callback indicated error after header read
 745  */
 746 static int
 747 _VHandleVolumeHeader(struct DiskPartition64 *dp, VWalkVolFunc volfunc,
 748                      const char *name, struct VolumeDiskHeader *hdr,
 749                      int locked, void *rock)
 750 {
 751     int error = 0;
 752     FD_t fd;
 753
 754     if ((fd = OS_OPEN(name, O_RDONLY, 0)) == INVALID_FD
 755         || OS_READ(fd, hdr, sizeof(*hdr))
 756         != sizeof(*hdr)
 757         || hdr->stamp.magic != VOLUMEHEADERMAGIC) {
 758         error = 1;
 759     }
 760
 761     if (fd != INVALID_FD) {
 762         OS_CLOSE(fd);
 763     }
 764
 765 #ifdef AFSFS_DEMAND_ATTACH_FS
 766     if (locked) {
 767         VPartHeaderUnlock(dp);
 768     }
 769 #endif /* AFS_DEMAND_ATTACH_FS */
 770
 771     if (!error && volfunc) {
 772         /* the volume header seems fine; call the caller-supplied
 773          * 'we-found-a-volume-header' function */
 774         int last = 1;
 775
 776 #ifdef AFS_DEMAND_ATTACH_FS
 777         if (!locked) {
 778             last = 0;
 779         }
 780 #endif /* AFS_DEMAND_ATTACH_FS */
 781
 782         error = (*volfunc) (dp, name, hdr, last, rock);
 783         if (error < 0) {
 784             return -1;
 785         }
 786         if (error) {
 787             error = 2;
 788         }
 789     }
 790
 791 #ifdef AFS_DEMAND_ATTACH_FS
 792     if (error && !locked) {
 793         int code;
 794         /* retry reading the volume header under the partition
 795          * header lock, just to be safe and ensure we're not
 796          * racing something rewriting the vol header */
 797         code = VPartHeaderLock(dp, WRITE_LOCK);
 798         if (code) {
 799             Log("Error acquiring partition write lock when "
 800                 "looking at header %s\n", name);
 801             return -1;
 802         }
 803
 804         return _VHandleVolumeHeader(dp, volfunc, name, hdr, 1, rock);
 805     }
 806 #endif /* AFS_DEMAND_ATTACH_FS */
 807
 808     return error;
 809 }
 810
 811 /**
 812  * walk through the list of volume headers on a partition.
 813  *
 814  * This function looks through all of the .vol headers on a partition, reads in
 815  * each header, and calls the supplied volfunc function on each one. If the
 816  * header cannot be read (or volfunc returns a positive error code), DAFS will
 817  * VPartHeaderExLock() and retry. If that fails, or if we are non-DAFS, errfunc
 818  * will be called (which typically will unlink the problem volume header).
 819  *
 820  * If volfunc returns a negative error code, walking the partition will stop
 821  * and we will return an error immediately.
 822  *
 823  * @param[in] dp       partition to walk
 824  * @param[in] partpath the path opendir()
 825  * @param[in] volfunc  the function to call when a header is encountered, or
 826  *                     NULL to just skip over valid headers
 827  * @param[in] errfunc  the function to call when a problematic header is
 828  *                     encountered, or NULL to just skip over bad headers
 829  * @param[in] rock     rock for volfunc and errfunc
 830  *
 831  * @see VWalkVolFunc
 832  * @see VWalkErrFunc
 833  *
 834  * @return operation status
 835  *  @retval 0 success
 836  *  @retval negative fatal error, walk did not finish
 837  */
 838 int
 839 VWalkVolumeHeaders(struct DiskPartition64 *dp, const char *partpath,
 840                    VWalkVolFunc volfunc, VWalkErrFunc errfunc, void *rock)
 841 {
 842     DIR *dirp;
 843     struct dirent *dentry;
 844     int code = 0;
 845     struct VolumeDiskHeader diskHeader;
 846
 847     dirp = opendir(partpath);
 848     if (!dirp) {
 849         Log("VWalkVolumeHeaders: cannot open directory %s\n", partpath);
 850         code = -1;
 851         goto done;
 852     }
 853
 854     while ((dentry = readdir(dirp)) != NULL) {
 855         char *p;
 856         p = strrchr(dentry->d_name, '.');
 857         if (p != NULL && strcmp(p, VHDREXT) == 0) {
 858             char name[VMAXPATHLEN];
 859
 860             snprintf(name, VMAXPATHLEN, "%s" OS_DIRSEP "%s", partpath, dentry->d_name);
 861
 862             code = _VHandleVolumeHeader(dp, volfunc, name, &diskHeader, -1, rock);
 863             if (code < 0) {
 864                 /* fatal error, stop walking */
 865                 goto done;
 866             }
 867             if (code && errfunc) {
 868                 /* error with header; call the caller-supplied vol error
 869                  * function */
 870
 871                 struct VolumeDiskHeader *hdr = &diskHeader;
 872                 if (code == 1) {
 873                     /* we failed to read the header at all, so don't pass in
 874                      * the header ptr */
 875                     hdr = NULL;
 876                 }
 877                 (*errfunc) (dp, name, hdr, rock);
 878             }
 879             code = 0;
 880         }
 881     }
 882  done:
 883     if (dirp) {
 884         closedir(dirp);
 885         dirp = NULL;
 886     }
 887
 888     return code;
 889 }
 890
 891 /**
 892  * initialize a struct VLockFile.
 893  *
 894  * @param[in] lf   struct VLockFile to initialize
 895  * @param[in] path Full path to the file to use for locks. The string contents
 896  *                 are copied.
 897  */
 898 void
 899 VLockFileInit(struct VLockFile *lf, const char *path)
 900 {
 901     memset(lf, 0, sizeof(*lf));
 902     lf->path = strdup(path);
 903     lf->fd = INVALID_FD;
 904     opr_mutex_init(&lf->mutex);
 905 }
 906
 907 #ifdef AFS_NT40_ENV
 908 static_inline FD_t
 909 _VOpenPath(const char *path)
 910 {
 911     HANDLE handle;
 912
 913     handle = CreateFile(path,
 914                         GENERIC_READ | GENERIC_WRITE,
 915                         FILE_SHARE_READ | FILE_SHARE_WRITE,
 916                         NULL,
 917                         OPEN_ALWAYS,
 918                         FILE_ATTRIBUTE_HIDDEN,
 919                         NULL);
 920     if (handle == INVALID_HANDLE_VALUE) {
 921         return INVALID_FD;
 922     }
 923
 924     return handle;
 925 }
 926
 927 static_inline int
 928 _VLockFd(FD_t handle, afs_uint32 offset, int locktype, int nonblock)
 929 {
 930     DWORD flags = 0;
 931     OVERLAPPED lap;
 932
 933     if (locktype == WRITE_LOCK) {
 934         flags |= LOCKFILE_EXCLUSIVE_LOCK;
 935     }
 936     if (nonblock) {
 937         flags |= LOCKFILE_FAIL_IMMEDIATELY;
 938     }
 939
 940     memset(&lap, 0, sizeof(lap));
 941     lap.Offset = offset;
 942
 943     if (!LockFileEx(handle, flags, 0, 1, 0, &lap)) {
 944         if (GetLastError() == ERROR_LOCK_VIOLATION) {
 945             return EBUSY;
 946         }
 947         return EIO;
 948     }
 949
 950     return 0;
 951 }
 952
 953 static_inline void
 954 _VUnlockFd(FD_t handle, afs_uint32 offset)
 955 {
 956     OVERLAPPED lap;
 957
 958     memset(&lap, 0, sizeof(lap));
 959     lap.Offset = offset;
 960
 961     UnlockFileEx(handle, 0, 1, 0, &lap);
 962 }
 963
 964 static_inline void
 965 _VCloseFd(FD_t handle)
 966 {
 967     CloseHandle(handle);
 968 }
 969
 970 #else /* !AFS_NT40_ENV */
 971
 972 /**
 973  * open a file on the local filesystem suitable for locking
 974  *
 975  * @param[in] path  abs path of the file to open
 976  *
 977  * @return file descriptor
 978  *  @retval INVALID_FD failure opening file
 979  */
 980 static_inline FD_t
 981 _VOpenPath(const char *path)
 982 {
 983     int fd;
 984
 985     fd = open(path, O_RDWR | O_CREAT, 0660);
 986     if (fd < 0) {
 987         return INVALID_FD;
 988     }
 989     return fd;
 990 }
 991
 992 /**
 993  * lock an offset in a file descriptor.
 994  *
 995  * @param[in] fd       file descriptor to lock
 996  * @param[in] offset   offset in file to lock
 997  * @param[in] locktype READ_LOCK or WRITE_LOCK
 998  * @param[in] nonblock 1 to fail immediately, 0 to wait to acquire lock
 999  *
1000  * @return operation status
1001  *  @retval 0 success
1002  *  @retval EBUSY someone else is holding a conflicting lock and nonblock=1 was
1003  *                specified
1004  *  @retval EIO   error acquiring file lock
1005  */
1006 static_inline int
1007 _VLockFd(FD_t fd, afs_uint32 offset, int locktype, int nonblock)
1008 {
1009     int l_type = F_WRLCK;
1010     int cmd = AFS_SETLKW;
1011     struct afs_st_flock sf;
1012
1013     opr_Assert(fd >= 0);
1014
1015     if (locktype == READ_LOCK) {
1016         l_type = F_RDLCK;
1017     }
1018     if (nonblock) {
1019         cmd = AFS_SETLK;
1020     }
1021
1022     sf.l_start = offset;
1023     sf.l_len = 1;
1024     sf.l_type = l_type;
1025     sf.l_whence = SEEK_SET;
1026
1027     if (fcntl(fd, cmd, &sf)) {
1028         if (nonblock && (errno == EACCES || errno == EAGAIN)) {
1029             /* We asked for a nonblocking lock, and it was already locked */
1030             sf.l_pid = 0;
1031             if (fcntl(fd, F_GETLK, &sf) != 0 || sf.l_pid == 0) {
1032                 Log("_VLockFd: fcntl failed with error %d when trying to "
1033                     "query the conflicting lock for fd %d (locktype=%d, "
1034                     "offset=%lu)\n", errno, fd, locktype,
1035                     afs_printable_uint32_lu(offset));
1036             } else {
1037                 Log("_VLockFd: conflicting lock held on fd %d, offset %lu by "
1038                     "pid %ld (locktype=%d)\n", fd,
1039                     afs_printable_uint32_lu(offset), (long int)sf.l_pid,
1040                     locktype);
1041             }
1042             return EBUSY;
1043         }
1044         Log("_VLockFd: fcntl failed with error %d when trying to lock "
1045             "fd %d (locktype=%d, offset=%lu)\n", errno, fd, locktype,
1046             afs_printable_uint32_lu(offset));
1047         return EIO;
1048     }
1049
1050     return 0;
1051 }
1052
1053 /**
1054  * close a file descriptor used for file locking.
1055  *
1056  * @param[in] fd file descriptor to close
1057  */
1058 static_inline void
1059 _VCloseFd(FD_t fd)
1060 {
1061     if (close(fd)) {
1062         Log("_VCloseFd: error %d closing fd %d\n",
1063             errno, fd);
1064     }
1065 }
1066
1067 /**
1068  * unlock a file offset in a file descriptor.
1069  *
1070  * @param[in] fd file descriptor to unlock
1071  * @param[in] offset offset to unlock
1072  */
1073 static_inline void
1074 _VUnlockFd(FD_t fd, afs_uint32 offset)
1075 {
1076     struct afs_st_flock sf;
1077
1078     sf.l_start = offset;
1079     sf.l_len = 1;
1080     sf.l_type = F_UNLCK;
1081     sf.l_whence = SEEK_SET;
1082
1083     if (fcntl(fd, AFS_SETLK, &sf)) {
1084         Log("_VUnlockFd: fcntl failed with error %d when trying to unlock "
1085             "fd %d\n", errno, fd);
1086     }
1087 }
1088 #endif /* !AFS_NT40_ENV */
1089
1090 /**
1091  * reinitialize a struct VLockFile.
1092  *
1093  * Use this to close the lock file (unlocking any locks in it), and effectively
1094  * restore lf to the state it was in when it was initialized. This is the same
1095  * as unlocking all of the locks on the file, without having to remember what
1096  * all of the locks were. Do not unlock previously held locks after calling
1097  * this.
1098  *
1099  * @param[in] lf  struct VLockFile to reinit
1100  *
1101  * @pre nobody is waiting for a lock on this lockfile or otherwise using
1102  *      this lockfile at all
1103  */
1104 void
1105 VLockFileReinit(struct VLockFile *lf)
1106 {
1107     opr_mutex_enter(&lf->mutex);
1108
1109     if (lf->fd != INVALID_FD) {
1110         _VCloseFd(lf->fd);
1111         lf->fd = INVALID_FD;
1112     }
1113
1114     lf->refcount = 0;
1115
1116     opr_mutex_exit(&lf->mutex);
1117 }
1118
1119 /**
1120  * lock a file on disk for the process.
1121  *
1122  * @param[in] lf       the struct VLockFile representing the file to lock
1123  * @param[in] offset   the offset in the file to lock
1124  * @param[in] locktype READ_LOCK or WRITE_LOCK
1125  * @param[in] nonblock 0 to wait for conflicting locks to clear before
1126  *                     obtaining the lock; 1 to fail immediately if a
1127  *                     conflicting lock is held by someone else
1128  *
1129  * @return operation status
1130  *  @retval 0 success
1131  *  @retval EBUSY someone else is holding a conflicting lock and nonblock=1 was
1132  *                specified
1133  *  @retval EIO   error acquiring file lock
1134  *
1135  * @note DAFS only
1136  *
1137  * @note do not try to lock/unlock the same offset in the same file from
1138  * different threads; use VGetDiskLock to protect threads from each other in
1139  * addition to other processes
1140  */
1141 int
1142 VLockFileLock(struct VLockFile *lf, afs_uint32 offset, int locktype, int nonblock)
1143 {
1144     int code;
1145
1146     opr_Assert(locktype == READ_LOCK || locktype == WRITE_LOCK);
1147
1148     opr_mutex_enter(&lf->mutex);
1149
1150     if (lf->fd == INVALID_FD) {
1151         opr_Assert(lf->refcount == 0);
1152         lf->fd = _VOpenPath(lf->path);
1153         if (lf->fd == INVALID_FD) {
1154             opr_mutex_exit(&lf->mutex);
1155             return EIO;
1156         }
1157     }
1158
1159     lf->refcount++;
1160
1161     opr_Assert(lf->refcount > 0);
1162
1163     opr_mutex_exit(&lf->mutex);
1164
1165     code = _VLockFd(lf->fd, offset, locktype, nonblock);
1166
1167     if (code) {
1168         opr_mutex_enter(&lf->mutex);
1169         opr_Assert(lf->refcount > 0);
1170         if (--lf->refcount < 1) {
1171             _VCloseFd(lf->fd);
1172             lf->fd = INVALID_FD;
1173         }
1174         opr_mutex_exit(&lf->mutex);
1175     }
1176
1177     return code;
1178 }
1179
1180 void
1181 VLockFileUnlock(struct VLockFile *lf, afs_uint32 offset)
1182 {
1183     opr_mutex_enter(&lf->mutex);
1184
1185     opr_Assert(lf->fd != INVALID_FD);
1186     opr_Assert(lf->refcount > 0);
1187
1188     if (--lf->refcount < 1) {
1189         _VCloseFd(lf->fd);
1190         lf->fd = INVALID_FD;
1191     } else {
1192         _VUnlockFd(lf->fd, offset);
1193     }
1194
1195     opr_mutex_exit(&lf->mutex);
1196 }
1197
1198 #ifdef AFS_DEMAND_ATTACH_FS
1199
1200 /**
1201  * initialize a struct VDiskLock.
1202  *
1203  * @param[in] dl struct VDiskLock to initialize
1204  * @param[in] lf the struct VLockFile to associate with this disk lock
1205  */
1206 void
1207 VDiskLockInit(struct VDiskLock *dl, struct VLockFile *lf, afs_uint32 offset)
1208 {
1209     opr_Assert(lf);
1210     memset(dl, 0, sizeof(*dl));
1211     Lock_Init(&dl->rwlock);
1212     opr_mutex_init(&dl->mutex);
1213     opr_cv_init(&dl->cv);
1214     dl->lockfile = lf;
1215     dl->offset = offset;
1216 }
1217
1218 /**
1219  * acquire a lock on a file on local disk.
1220  *
1221  * @param[in] dl       the VDiskLock structure corresponding to the file on disk
1222  * @param[in] locktype READ_LOCK if you want a read lock, or WRITE_LOCK if
1223  *                     you want a write lock
1224  * @param[in] nonblock 0 to wait for conflicting locks to clear before
1225  *                     obtaining the lock; 1 to fail immediately if a
1226  *                     conflicting lock is held by someone else
1227  *
1228  * @return operation status
1229  *  @retval 0 success
1230  *  @retval EBUSY someone else is holding a conflicting lock and nonblock=1 was
1231  *                specified
1232  *  @retval EIO   error acquiring file lock
1233  *
1234  * @note DAFS only
1235  *
1236  * @note while normal fcntl-y locks on Unix systems generally only work per-
1237  * process, this interface also deals with locks between threads in the
1238  * process in addition to different processes acquiring the lock
1239  */
1240 int
1241 VGetDiskLock(struct VDiskLock *dl, int locktype, int nonblock)
1242 {
1243     int code = 0;
1244     opr_Assert(locktype == READ_LOCK || locktype == WRITE_LOCK);
1245
1246     if (nonblock) {
1247         if (locktype == READ_LOCK) {
1248             ObtainReadLockNoBlock(&dl->rwlock, code);
1249         } else {
1250             ObtainWriteLockNoBlock(&dl->rwlock, code);
1251         }
1252
1253         if (code) {
1254             return EBUSY;
1255         }
1256
1257     } else if (locktype == READ_LOCK) {
1258         ObtainReadLock(&dl->rwlock);
1259     } else {
1260         ObtainWriteLock(&dl->rwlock);
1261     }
1262
1263     opr_mutex_enter(&dl->mutex);
1264
1265     if ((dl->flags & VDISKLOCK_ACQUIRING)) {
1266         /* Some other thread is waiting to acquire an fs lock. If nonblock=1,
1267          * we can return immediately, since we know we'll need to wait to
1268          * acquire. Otherwise, wait for the other thread to finish acquiring
1269          * the fs lock */
1270         if (nonblock) {
1271             code = EBUSY;
1272         } else {
1273             while ((dl->flags & VDISKLOCK_ACQUIRING)) {
1274                 opr_cv_wait(&dl->cv, &dl->mutex);
1275             }
1276         }
1277     }
1278
1279     if (code == 0 && !(dl->flags & VDISKLOCK_ACQUIRED)) {
1280         /* no other thread holds the lock on the actual file; so grab one */
1281
1282         /* first try, don't block on the lock to see if we can get it without
1283          * waiting */
1284         code = VLockFileLock(dl->lockfile, dl->offset, locktype, 1);
1285
1286         if (code == EBUSY && !nonblock) {
1287
1288             /* mark that we are waiting on the fs lock */
1289             dl->flags |= VDISKLOCK_ACQUIRING;
1290
1291             opr_mutex_exit(&dl->mutex);
1292             code = VLockFileLock(dl->lockfile, dl->offset, locktype, nonblock);
1293             opr_mutex_enter(&dl->mutex);
1294
1295             dl->flags &= ~VDISKLOCK_ACQUIRING;
1296
1297             if (code == 0) {
1298                 dl->flags |= VDISKLOCK_ACQUIRED;
1299             }
1300
1301             opr_cv_broadcast(&dl->cv);
1302         }
1303     }
1304
1305     if (code) {
1306         if (locktype == READ_LOCK) {
1307             ReleaseReadLock(&dl->rwlock);
1308         } else {
1309             ReleaseWriteLock(&dl->rwlock);
1310         }
1311     } else {
1312         /* successfully got the lock, so inc the number of unlocks we need
1313          * to do before we can unlock the actual file */
1314         ++dl->lockers;
1315     }
1316
1317     opr_mutex_exit(&dl->mutex);
1318
1319     return code;
1320 }
1321
1322 /**
1323  * release a lock on a file on local disk.
1324  *
1325  * @param[in] dl the struct VDiskLock to release
1326  * @param[in] locktype READ_LOCK if you are unlocking a read lock, or
1327  *                     WRITE_LOCK if you are unlocking a write lock
1328  *
1329  * @return operation status
1330  *  @retval 0 success
1331  */
1332 void
1333 VReleaseDiskLock(struct VDiskLock *dl, int locktype)
1334 {
1335     opr_Assert(locktype == READ_LOCK || locktype == WRITE_LOCK);
1336
1337     opr_mutex_enter(&dl->mutex);
1338     opr_Assert(dl->lockers > 0);
1339
1340     if (--dl->lockers < 1) {
1341         /* no threads are holding this lock anymore, so we can release the
1342          * actual disk lock */
1343         VLockFileUnlock(dl->lockfile, dl->offset);
1344         dl->flags &= ~VDISKLOCK_ACQUIRED;
1345     }
1346
1347     opr_mutex_exit(&dl->mutex);
1348
1349     if (locktype == READ_LOCK) {
1350         ReleaseReadLock(&dl->rwlock);
1351     } else {
1352         ReleaseWriteLock(&dl->rwlock);
1353     }
1354 }
1355
1356 #endif /* AFS_DEMAND_ATTACH_FS */