src/afs/LINUX/osi_export.c

   1 /*
   2  * vi:set cin noet sw=4 tw=70:
   3  * Copyright 2006, International Business Machines Corporation and others.
   4  * All Rights Reserved.
   5  *
   6  * This software has been released under the terms of the IBM Public
   7  * License.  For details, see the LICENSE file in the top-level source
   8  * directory or online at http://www.openafs.org/dl/license10.html
   9  */
  10
  11 /*
  12  * Filesystem export operations for Linux
  13  */
  14 #include <afsconfig.h>
  15 #include "afs/param.h"
  16
  17
  18 #include <linux/module.h> /* early to avoid printf->printk mapping */
  19 #include <linux/fs.h>
  20 #ifdef HAVE_LINUX_EXPORTFS_H
  21 #include <linux/exportfs.h>
  22 #endif
  23 #include "afs/sysincludes.h"
  24 #include "afsincludes.h"
  25 #include "afs/afs_dynroot.h"
  26
  27 #if !defined(AFS_NONFSTRANS)
  28
  29 /* #define OSI_EXPORT_DEBUG */
  30
  31 extern struct dentry_operations afs_dentry_operations;
  32 #if defined(NEW_EXPORT_OPS)
  33 static struct dentry *afs_export_get_dentry(struct super_block *sb,
  34                                             void *inump);
  35 #endif
  36
  37 struct get_name_data {
  38     char *name;
  39     struct VenusFid fid;
  40     int found;
  41 };
  42
  43 /*
  44  * Linux reserved the following filehandle types:
  45  * - 0 is always the filesystem root; NFS deals with this for us
  46  * - 1,2 are reserved by Linux for inode-number-based filehandles
  47  * - 0xff is reserved by linux
  48  *
  49  * We encode filehandles for AFS files using the types defined below.
  50  * Internally, our "object ID" is a VenusFid; if we get a filehandle
  51  * with a more-stable cell ID, we'll turn it into a cell number in
  52  * the decode_fh wrapper.
  53  */
  54
  55 #define AFSFH_VENUSFID      0xa0 /* cell, volume, vnode, uniq           */
  56 #define AFSFH_CELLFID       0xa1 /* cellhandle, volume, vnode, uniq     */
  57 #define AFSFH_NET_VENUSFID  0xa2 /* net cell, volume, vnode, uniq       */
  58 #define AFSFH_NET_CELLFID   0xa3 /* net cellhandle, volume, vnode, uniq */
  59 #define AFSFH_DYN_RO_CELL   0xd0 /* cellhandle for RO root.cell mount   */
  60 #define AFSFH_DYN_RW_CELL   0xd1 /* cellhandle for RW root.cell mount   */
  61 #define AFSFH_DYN_RO_LINK   0xd2 /* cellhandle for RO root.cell symlink */
  62 #define AFSFH_DYN_RW_LINK   0xd3 /* cellhandle for RW root.cell symlink */
  63 #define AFSFH_DYN_MOUNT     0xd4 /* cellhandle, volume for mount point  */
  64 #define AFSFH_DYN_SYMLINK   0xd5 /* hash of dynroot symlink target */
  65
  66 static int afs_encode_fh(struct dentry *de, __u32 *fh, int *max_len,
  67                          int connectable)
  68 {
  69     struct vcache *tvc;
  70     struct cell *tc;
  71     int vntype;
  72
  73     if (!de->d_inode) /* encode a negative dentry?! */
  74         return 255;
  75     if (*max_len < 4)  /* not enough space */
  76         return 255;
  77
  78     tvc = VTOAFS(de->d_inode);
  79
  80 #ifdef OSI_EXPORT_DEBUG
  81     printk("afs: encode_fh(0x%08x/%d/%d.%d)\n",
  82            tvc->f.fid.Cell,      tvc->f.fid.Fid.Volume,
  83            tvc->f.fid.Fid.Vnode, tvc->f.fid.Fid.Unique);
  84 #endif
  85     if (afs_IsDynrootAnyFid(&tvc->f.fid)) {
  86         vntype = VNUM_TO_VNTYPE(tvc->f.fid.Fid.Vnode);
  87         switch (vntype) {
  88             case 0:
  89                 /* encode as a normal filehandle */
  90                 break;
  91
  92             case VN_TYPE_MOUNT:
  93                 if (*max_len < 5) {
  94                     return 255;
  95                 }
  96                 /* fall through */
  97
  98             case VN_TYPE_CELL:
  99             case VN_TYPE_ALIAS:
 100                 AFS_GLOCK();
 101                 tc = afs_GetCellByIndex(VNUM_TO_CIDX(tvc->f.fid.Fid.Vnode),
 102                                         READ_LOCK);
 103                 if (!tc) {
 104                     AFS_GUNLOCK();
 105                     return 255;
 106                 }
 107                 memcpy((void *)fh, tc->cellHandle, 16);
 108                 afs_PutCell(tc, READ_LOCK);
 109                 AFS_GUNLOCK();
 110                 if (vntype == VN_TYPE_MOUNT) {
 111                     fh[4] = htonl(tvc->f.fid.Fid.Unique);
 112                     *max_len = 5;
 113                     return AFSFH_DYN_MOUNT;
 114                 }
 115                 *max_len = 4;
 116                 if (vntype == VN_TYPE_CELL) {
 117                     return AFSFH_DYN_RO_CELL | VNUM_TO_RW(tvc->f.fid.Fid.Vnode);
 118                 } else {
 119                     return AFSFH_DYN_RO_LINK | VNUM_TO_RW(tvc->f.fid.Fid.Vnode);
 120                 }
 121
 122             case VN_TYPE_SYMLINK:
 123                 /* XXX fill in filehandle for dynroot symlink */
 124                 /* XXX return AFSFH_DYN_SYMLINK; */
 125
 126             default:
 127                 return 255;
 128         }
 129     }
 130
 131     if (*max_len < 7) {
 132         /* not big enough for a migratable filehandle */
 133         /* always encode in network order */
 134         fh[0] = htonl(tvc->f.fid.Cell);
 135         fh[1] = htonl(tvc->f.fid.Fid.Volume);
 136         fh[2] = htonl(tvc->f.fid.Fid.Vnode);
 137         fh[3] = htonl(tvc->f.fid.Fid.Unique);
 138         *max_len = 4;
 139         return AFSFH_NET_VENUSFID;
 140     }
 141
 142     AFS_GLOCK();
 143     tc = afs_GetCell(tvc->f.fid.Cell, READ_LOCK);
 144     if (!tc) {
 145         AFS_GUNLOCK();
 146         return 255;
 147     }
 148     memcpy((void *)fh, tc->cellHandle, 16);
 149     afs_PutCell(tc, READ_LOCK);
 150     AFS_GUNLOCK();
 151     /* always encode in network order */
 152     fh[4] = htonl(tvc->f.fid.Fid.Volume);
 153     fh[5] = htonl(tvc->f.fid.Fid.Vnode);
 154     fh[6] = htonl(tvc->f.fid.Fid.Unique);
 155
 156     *max_len = 7;
 157     return AFSFH_NET_CELLFID;
 158 }
 159
 160 #if defined(NEW_EXPORT_OPS)
 161 static struct dentry *afs_fh_to_dentry(struct super_block *sb, struct fid *fh_fid,
 162                                     int fh_len, int fh_type)
 163 #else
 164 static struct dentry *afs_decode_fh(struct super_block *sb, __u32 *fh,
 165                                     int fh_len, int fh_type,
 166                                     int (*acceptable)(void *, struct dentry *),
 167                                     void *context)
 168 #endif
 169 {
 170     struct VenusFid fid;
 171     struct cell *tc;
 172     struct dentry *result;
 173 #if defined(NEW_EXPORT_OPS)
 174     __u32 *fh = (__u32 *)fh_fid->raw;
 175 #endif
 176
 177
 178     switch (fh_type) {
 179         case AFSFH_VENUSFID:
 180             if (fh_len != 4)
 181                 return NULL;
 182             fid.Cell       = fh[0];
 183             fid.Fid.Volume = fh[1];
 184             fid.Fid.Vnode  = fh[2];
 185             fid.Fid.Unique = fh[3];
 186             break;
 187
 188         case AFSFH_CELLFID:
 189             if (fh_len != 7)
 190                 return NULL;
 191             AFS_GLOCK();
 192             tc = afs_GetCellByHandle((void *)fh, READ_LOCK);
 193             if (!tc) {
 194                 AFS_GUNLOCK();
 195                 return NULL;
 196             }
 197             fid.Cell       = tc->cellNum;
 198             fid.Fid.Volume = fh[4];
 199             fid.Fid.Vnode  = fh[5];
 200             fid.Fid.Unique = fh[6];
 201             afs_PutCell(tc, READ_LOCK);
 202             AFS_GUNLOCK();
 203             break;
 204
 205         case AFSFH_NET_VENUSFID:
 206             fid.Cell       = ntohl(fh[0]);
 207             fid.Fid.Volume = ntohl(fh[1]);
 208             fid.Fid.Vnode  = ntohl(fh[2]);
 209             fid.Fid.Unique = ntohl(fh[3]);
 210             break;
 211
 212         case AFSFH_NET_CELLFID:
 213             if (fh_len != 7)
 214                 return NULL;
 215             AFS_GLOCK();
 216             tc = afs_GetCellByHandle((void *)fh, READ_LOCK);
 217             if (!tc) {
 218                 AFS_GUNLOCK();
 219                 return NULL;
 220             }
 221             fid.Cell       = tc->cellNum;
 222             fid.Fid.Volume = ntohl(fh[4]);
 223             fid.Fid.Vnode  = ntohl(fh[5]);
 224             fid.Fid.Unique = ntohl(fh[6]);
 225             afs_PutCell(tc, READ_LOCK);
 226             AFS_GUNLOCK();
 227             break;
 228
 229         case AFSFH_DYN_RO_CELL:
 230         case AFSFH_DYN_RW_CELL:
 231             if (fh_len != 4)
 232                 return NULL;
 233             AFS_GLOCK();
 234             tc = afs_GetCellByHandle((void *)fh, READ_LOCK);
 235             if (!tc) {
 236                 AFS_GUNLOCK();
 237                 return NULL;
 238             }
 239             afs_GetDynrootFid(&fid);
 240             fid.Fid.Vnode  = VNUM_FROM_CIDX_RW(tc->cellIndex, fh_type & 1);
 241             fid.Fid.Unique = 1;
 242             afs_PutCell(tc, READ_LOCK);
 243             AFS_GUNLOCK();
 244             break;
 245
 246         case AFSFH_DYN_RO_LINK:
 247         case AFSFH_DYN_RW_LINK:
 248             if (fh_len != 4)
 249                 return NULL;
 250             AFS_GLOCK();
 251             tc = afs_GetCellByHandle((void *)fh, READ_LOCK);
 252             if (!tc) {
 253                 AFS_GUNLOCK();
 254                 return NULL;
 255             }
 256             afs_GetDynrootFid(&fid);
 257             fid.Fid.Vnode  = VNUM_FROM_CAIDX_RW(tc->cellIndex, fh_type & 1);
 258             fid.Fid.Unique = 1;
 259             afs_PutCell(tc, READ_LOCK);
 260             AFS_GUNLOCK();
 261             break;
 262
 263         case AFSFH_DYN_MOUNT:
 264             if (fh_len != 5)
 265                 return NULL;
 266             AFS_GLOCK();
 267             tc = afs_GetCellByHandle((void *)fh, READ_LOCK);
 268             if (!tc) {
 269                 AFS_GUNLOCK();
 270                 return NULL;
 271             }
 272             afs_GetDynrootFid(&fid);
 273             fid.Fid.Vnode  = VNUM_FROM_TYPEID(VN_TYPE_MOUNT,
 274                                               tc->cellIndex << 2);
 275             fid.Fid.Unique = ntohl(fh[4]);
 276             afs_PutCell(tc, READ_LOCK);
 277             AFS_GUNLOCK();
 278             break;
 279
 280         case AFSFH_DYN_SYMLINK:
 281             /* XXX parse dynroot symlink filehandle */
 282             /* break; */
 283
 284         default:
 285             return NULL;
 286     }
 287
 288 #if defined(NEW_EXPORT_OPS)
 289     result = afs_export_get_dentry(sb, &fid);
 290 #else
 291     result = sb->s_export_op->find_exported_dentry(sb, &fid, 0,
 292                                                    acceptable, context);
 293
 294 #endif
 295
 296 #ifdef OSI_EXPORT_DEBUG
 297     if (!result) {
 298         printk("afs: decode_fh(0x%08x/%d/%d.%d): no dentry\n",
 299                fid.Cell,      fid.Fid.Volume,
 300                fid.Fid.Vnode, fid.Fid.Unique);
 301     } else if (IS_ERR(result)) {
 302         printk("afs: decode_fh(0x%08x/%d/%d.%d): error %ld\n",
 303                fid.Cell,      fid.Fid.Volume,
 304                fid.Fid.Vnode, fid.Fid.Unique, PTR_ERR(result));
 305     }
 306 #endif
 307     return result;
 308 }
 309
 310 static int update_dir_parent(struct vrequest *areq, struct vcache *adp)
 311 {
 312     struct VenusFid tfid;
 313     struct dcache *tdc;
 314     afs_size_t dirOffset, dirLen;
 315     int code;
 316
 317 redo:
 318     if (!(adp->f.states & CStatd)) {
 319         if ((code = afs_VerifyVCache2(adp, areq))) {
 320 #ifdef OSI_EXPORT_DEBUG
 321             printk("afs: update_dir_parent(0x%08x/%d/%d.%d): VerifyVCache2: %d\n",
 322                    adp->f.fid.Cell,      adp->f.fid.Fid.Volume,
 323                    adp->f.fid.Fid.Vnode, adp->f.fid.Fid.Unique, code);
 324 #endif
 325             return code;
 326         }
 327     }
 328
 329     tdc = afs_GetDCache(adp, (afs_size_t) 0, areq, &dirOffset, &dirLen, 1);
 330     if (!tdc) {
 331 #ifdef OSI_EXPORT_DEBUG
 332         printk("afs: update_dir_parent(0x%08x/%d/%d.%d): no dcache\n",
 333                adp->f.fid.Cell,      adp->f.fid.Fid.Volume,
 334                adp->f.fid.Fid.Vnode, adp->f.fid.Fid.Unique);
 335 #endif
 336         return EIO;
 337     }
 338
 339     /* now we will just call dir package with appropriate inode.
 340      * Dirs are always fetched in their entirety for now */
 341     ObtainSharedLock(&adp->lock, 801);
 342     ObtainReadLock(&tdc->lock);
 343
 344     /*
 345      * Make sure that the data in the cache is current. There are two
 346      * cases we need to worry about:
 347      * 1. The cache data is being fetched by another process.
 348      * 2. The cache data is no longer valid
 349      */
 350     while ((adp->f.states & CStatd)
 351            && (tdc->dflags & DFFetching)
 352            && hsame(adp->f.m.DataVersion, tdc->f.versionNo)) {
 353         ReleaseReadLock(&tdc->lock);
 354         ReleaseSharedLock(&adp->lock);
 355         afs_osi_Sleep(&tdc->validPos);
 356         ObtainSharedLock(&adp->lock, 802);
 357         ObtainReadLock(&tdc->lock);
 358     }
 359     if (!(adp->f.states & CStatd)
 360         || !hsame(adp->f.m.DataVersion, tdc->f.versionNo)) {
 361         ReleaseReadLock(&tdc->lock);
 362         ReleaseSharedLock(&adp->lock);
 363         afs_PutDCache(tdc);
 364 #ifdef OSI_EXPORT_DEBUG
 365         printk("afs: update_dir_parent(0x%08x/%d/%d.%d): dir changed; retrying\n",
 366                adp->f.fid.Cell,      adp->f.fid.Fid.Volume,
 367                adp->f.fid.Fid.Vnode, adp->f.fid.Fid.Unique);
 368 #endif
 369         goto redo;
 370     }
 371
 372     /* lookup the name in the appropriate dir, and return a cache entry
 373      * on the resulting fid */
 374     code = afs_dir_Lookup(tdc, "..", &tfid.Fid);
 375
 376     ReleaseReadLock(&tdc->lock);
 377     afs_PutDCache(tdc);
 378
 379     if (!code) {
 380         UpgradeSToWLock(&adp->lock, 803);
 381         adp->f.parent.vnode  = tfid.Fid.Vnode;
 382         adp->f.parent.unique = tfid.Fid.Unique;
 383     }
 384 #ifdef OSI_EXPORT_DEBUG
 385     if (code) {
 386         printk("afs: update_dir_parent(0x%08x/%d/%d.%d): afs_dir_Lookup: %d\n",
 387                adp->f.fid.Cell,      adp->f.fid.Fid.Volume,
 388                adp->f.fid.Fid.Vnode, adp->f.fid.Fid.Unique, code);
 389     } else {
 390         printk("afs: update_dir_parent(0x%08x/%d/%d.%d) => %d.%d\n",
 391                adp->f.fid.Cell,      adp->f.fid.Fid.Volume,
 392                adp->f.fid.Fid.Vnode, adp->f.fid.Fid.Unique,
 393                adp->parent.vnode,   adp->parent.unique);
 394     }
 395 #endif
 396     ReleaseSharedLock(&adp->lock);
 397     return code;
 398 }
 399
 400
 401 static int UnEvalFakeStat(struct vrequest *areq, struct vcache **vcpp)
 402 {
 403     struct VenusFid tfid;
 404     struct volume *tvp;
 405     struct vcache *tvc;
 406     int code;
 407
 408     if (!afs_fakestat_enable)
 409         return 0;
 410
 411     if (*vcpp == afs_globalVp || vType(*vcpp) != VDIR || (*vcpp)->mvstat != AFS_MVSTAT_ROOT)
 412         return 0;
 413
 414     /* Figure out what FID to look for */
 415     tvp = afs_GetVolume(&(*vcpp)->f.fid, 0, READ_LOCK);
 416     if (!tvp) {
 417 #ifdef OSI_EXPORT_DEBUG
 418         printk("afs: UnEvalFakeStat(0x%08x/%d/%d.%d): no volume\n",
 419                (*vcpp)->f.fid.Cell,      (*vcpp)->f.fid.Fid.Volume,
 420                (*vcpp)->f.fid.Fid.Vnode, (*vcpp)->f.fid.Fid.Unique);
 421 #endif
 422         return ENOENT;
 423     }
 424     tfid = tvp->mtpoint;
 425     afs_PutVolume(tvp, READ_LOCK);
 426
 427     tvc = afs_GetVCache(&tfid, areq, NULL, NULL);
 428     if (!tvc) {
 429 #ifdef OSI_EXPORT_DEBUG
 430         printk("afs: UnEvalFakeStat(0x%08x/%d/%d.%d): GetVCache(0x%08x/%d/%d.%d) failed\n",
 431                (*vcpp)->f.fid.Cell,      (*vcpp)->f.fid.Fid.Volume,
 432                (*vcpp)->f.fid.Fid.Vnode, (*vcpp)->f.fid.Fid.Unique,
 433                tfid.Cell,          tfid.Fid.Volume,
 434                tfid.Fid.Vnode,     tfid.Fid.Unique);
 435 #endif
 436         return ENOENT;
 437     }
 438
 439     if (afs_fakestat_enable == 2) {
 440         ObtainWriteLock(&tvc->lock, 806);
 441         code = afs_HandleLink(tvc, areq);
 442         if (code) {
 443             ReleaseWriteLock(&tvc->lock);
 444             afs_PutVCache(tvc);
 445             return code;
 446         }
 447         if (!strchr(tvc->linkData, ':')) {
 448             ReleaseWriteLock(&tvc->lock);
 449             afs_PutVCache(tvc);
 450             return 0;
 451         }
 452         ReleaseWriteLock(&tvc->lock);
 453     }
 454
 455     afs_PutVCache(*vcpp);
 456     *vcpp = tvc;
 457     return 0;
 458 }
 459
 460
 461 /*
 462  * Given a FID, obtain or construct a dentry, or return an error.
 463  * This should be called with the BKL and AFS_GLOCK held.
 464  */
 465 static struct dentry *get_dentry_from_fid(cred_t *credp, struct VenusFid *afid)
 466 {
 467     struct vrequest *treq = NULL;
 468     struct vcache *vcp;
 469     struct vattr *vattr = NULL;
 470     struct inode *ip;
 471     struct dentry *dp;
 472     afs_int32 code;
 473
 474     code = afs_CreateAttr(&vattr);
 475     if (code) {
 476         return ERR_PTR(-afs_CheckCode(code, NULL, 104));
 477     }
 478
 479     code = afs_CreateReq(&treq, credp);
 480     if (code) {
 481 #ifdef OSI_EXPORT_DEBUG
 482         printk("afs: get_dentry_from_fid(0x%08x/%d/%d.%d): afs_CreateReq: %d\n",
 483                afid->Cell, afid->Fid.Volume, afid->Fid.Vnode, afid->Fid.Unique,
 484                code);
 485 #endif
 486         afs_DestroyAttr(vattr);
 487         return ERR_PTR(-afs_CheckCode(code, NULL, 101));
 488     }
 489     vcp = afs_GetVCache(afid, treq, NULL, NULL);
 490     if (vcp == NULL) {
 491 #ifdef OSI_EXPORT_DEBUG
 492         printk("afs: get_dentry_from_fid(0x%08x/%d/%d.%d): no vcache\n",
 493                afid->Cell, afid->Fid.Volume, afid->Fid.Vnode, afid->Fid.Unique);
 494 #endif
 495         afs_DestroyReq(treq);
 496         afs_DestroyAttr(vattr);
 497         return NULL;
 498     }
 499
 500     /*
 501      * Now, it might be that we just caused a directory vnode to
 502      * spring into existence, in which case its parent FID is unset.
 503      * We need to do something about that, but only because we care
 504      * in our own get_parent(), below -- the common code never looks
 505      * at parentVnode on directories, except for VIOCGETVCXSTATUS.
 506      * So, if this fails, we don't really care very much.
 507      */
 508     if (vType(vcp) == VDIR && vcp->mvstat != AFS_MVSTAT_ROOT && !vcp->f.parent.vnode)
 509         update_dir_parent(treq, vcp);
 510
 511     /*
 512      * If this is a volume root directory and fakestat is enabled,
 513      * we might need to replace the directory by a mount point.
 514      */
 515     code = UnEvalFakeStat(treq, &vcp);
 516     if (code) {
 517 #ifdef OSI_EXPORT_DEBUG
 518         printk("afs: get_dentry_from_fid(0x%08x/%d/%d.%d): UnEvalFakeStat: %d\n",
 519                afid->Cell, afid->Fid.Volume, afid->Fid.Vnode, afid->Fid.Unique,
 520                code);
 521 #endif
 522         afs_PutVCache(vcp);
 523         code = afs_CheckCode(code, treq, 103);
 524         afs_DestroyReq(treq);
 525         afs_DestroyAttr(vattr);
 526         return ERR_PTR(-code);
 527     }
 528
 529     ip = AFSTOV(vcp);
 530     afs_getattr(vcp, vattr, credp);
 531     afs_fill_inode(ip, vattr);
 532
 533     /* d_alloc_anon might block, so we shouldn't hold the glock */
 534     AFS_GUNLOCK();
 535     dp = d_alloc_anon(ip);
 536     AFS_GLOCK();
 537
 538     if (!dp) {
 539         iput(ip);
 540 #ifdef OSI_EXPORT_DEBUG
 541         printk("afs: get_dentry_from_fid(0x%08x/%d/%d.%d): out of memory\n",
 542                afid->Cell, afid->Fid.Volume, afid->Fid.Vnode, afid->Fid.Unique);
 543 #endif
 544         afs_DestroyReq(treq);
 545         afs_DestroyAttr(vattr);
 546         return ERR_PTR(-ENOMEM);
 547     }
 548
 549     dp->d_op = &afs_dentry_operations;
 550     afs_DestroyReq(treq);
 551     afs_DestroyAttr(vattr);
 552     return dp;
 553 }
 554
 555 static struct dentry *afs_export_get_dentry(struct super_block *sb,
 556                                             void *inump)
 557 {
 558     struct dentry *dp;
 559     cred_t *credp;
 560
 561     credp = crref();
 562     AFS_GLOCK();
 563
 564     dp = get_dentry_from_fid(credp, inump);
 565
 566     AFS_GUNLOCK();
 567     crfree(credp);
 568
 569     return dp;
 570 }
 571
 572
 573 static int get_name_hook(void *hdata, char *name,
 574                          afs_int32 vnode, afs_int32 unique)
 575 {
 576     struct get_name_data *data = (struct get_name_data *)hdata;
 577     int len;
 578
 579     if (vnode == data->fid.Fid.Vnode && unique == data->fid.Fid.Unique) {
 580         len = strlen(name);
 581         if (len > NAME_MAX) len = NAME_MAX;
 582         memcpy(data->name, name, len);
 583         data->name[len] = '\0';
 584         data->found = 1;
 585     }
 586     return 0;
 587 }
 588
 589 static int afs_export_get_name(struct dentry *parent, char *name,
 590                                struct dentry *child)
 591 {
 592     struct afs_fakestat_state fakestate;
 593     struct get_name_data data;
 594     struct vrequest *treq = NULL;
 595     struct volume *tvp;
 596     struct vcache *vcp;
 597     struct dcache *tdc;
 598     cred_t *credp;
 599     afs_size_t dirOffset, dirLen;
 600     afs_int32 code = 0;
 601
 602     if (!parent->d_inode) {
 603 #ifdef OSI_EXPORT_DEBUG
 604         /* can't lookup name in a negative dentry */
 605         printk("afs: get_name(%s, %s): no parent inode\n",
 606                parent->d_name.name ? (char *)parent->d_name.name : "?",
 607                child->d_name.name  ? (char *)child->d_name.name  : "?");
 608 #endif
 609         return -EIO;
 610     }
 611     if (!child->d_inode) {
 612 #ifdef OSI_EXPORT_DEBUG
 613         /* can't find the FID of negative dentry */
 614         printk("afs: get_name(%s, %s): no child inode\n",
 615                parent->d_name.name ? (char *)parent->d_name.name : "?",
 616                child->d_name.name  ? (char *)child->d_name.name  : "?");
 617 #endif
 618         return -ENOENT;
 619     }
 620
 621     afs_InitFakeStat(&fakestate);
 622
 623     credp = crref();
 624     AFS_GLOCK();
 625
 626     vcp = VTOAFS(child->d_inode);
 627
 628     /* special case dynamic mount directory */
 629     if (afs_IsDynrootMount(vcp)) {
 630 #ifdef OSI_EXPORT_DEBUG
 631         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): this is the dynmount dir\n",
 632                parent->d_name.name ? (char *)parent->d_name.name : "?",
 633                vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 634                vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique);
 635 #endif
 636         data.fid = vcp->f.fid;
 637         if (VTOAFS(parent->d_inode) == afs_globalVp)
 638             strcpy(name, AFS_DYNROOT_MOUNTNAME);
 639         else
 640             code = -ENOENT;
 641         goto done;
 642     }
 643
 644     /* Figure out what FID to look for */
 645     if (vcp->mvstat == AFS_MVSTAT_ROOT) { /* volume root */
 646         tvp = afs_GetVolume(&vcp->f.fid, 0, READ_LOCK);
 647         if (!tvp) {
 648 #ifdef OSI_EXPORT_DEBUG
 649             printk("afs: get_name(%s, 0x%08x/%d/%d.%d): no volume for root\n",
 650                    parent->d_name.name ? (char *)parent->d_name.name : "?",
 651                    vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 652                    vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique);
 653 #endif
 654             code = ENOENT;
 655             goto done;
 656         }
 657         data.fid = tvp->mtpoint;
 658         afs_PutVolume(tvp, READ_LOCK);
 659     } else {
 660         data.fid = vcp->f.fid;
 661     }
 662
 663     vcp = VTOAFS(parent->d_inode);
 664 #ifdef OSI_EXPORT_DEBUG
 665     printk("afs: get_name(%s, 0x%08x/%d/%d.%d): parent is 0x%08x/%d/%d.%d\n",
 666            parent->d_name.name ? (char *)parent->d_name.name : "?",
 667            data.fid.Cell,      data.fid.Fid.Volume,
 668            data.fid.Fid.Vnode, data.fid.Fid.Unique,
 669            vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 670            vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique);
 671 #endif
 672     code = afs_CreateReq(&treq, credp);
 673     if (code) {
 674 #ifdef OSI_EXPORT_DEBUG
 675         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): afs_CreateReq: %d\n",
 676                parent->d_name.name ? (char *)parent->d_name.name : "?",
 677                data.fid.Cell,      data.fid.Fid.Volume,
 678                data.fid.Fid.Vnode, data.fid.Fid.Unique, code);
 679 #endif
 680         goto done;
 681     }
 682
 683     /* a dynamic mount point in the dynamic mount directory */
 684     if (afs_IsDynrootMount(vcp) && afs_IsDynrootAnyFid(&data.fid)
 685         && VNUM_TO_VNTYPE(data.fid.Fid.Vnode) == VN_TYPE_MOUNT) {
 686 #ifdef OSI_EXPORT_DEBUG
 687         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): dynamic mount point\n",
 688                parent->d_name.name ? (char *)parent->d_name.name : "?",
 689                data.fid.Cell,      data.fid.Fid.Volume,
 690                data.fid.Fid.Vnode, data.fid.Fid.Unique);
 691 #endif
 692         vcp = afs_GetVCache(&data.fid, treq, NULL, NULL);
 693         if (vcp) {
 694             ObtainReadLock(&vcp->lock);
 695             if (strlen(vcp->linkData + 1) <= NAME_MAX)
 696                 strcpy(name, vcp->linkData + 1);
 697             else
 698                 code = ENOENT;
 699             ReleaseReadLock(&vcp->lock);
 700             afs_PutVCache(vcp);
 701         } else {
 702 #ifdef OSI_EXPORT_DEBUG
 703             printk("afs: get_name(%s, 0x%08x/%d/%d.%d): no vcache\n",
 704                    parent->d_name.name ? (char *)parent->d_name.name : "?",
 705                    data.fid.Cell,      data.fid.Fid.Volume,
 706                    data.fid.Fid.Vnode, data.fid.Fid.Unique);
 707 #endif
 708             code = ENOENT;
 709         }
 710         goto done;
 711     }
 712
 713     code = afs_EvalFakeStat(&vcp, &fakestate, treq);
 714     if (code)
 715         goto done;
 716
 717     if (vcp->f.fid.Cell != data.fid.Cell ||
 718         vcp->f.fid.Fid.Volume != data.fid.Fid.Volume) {
 719         /* parent is not the expected cell and volume; thus it
 720          * cannot possibly contain the fid we are looking for */
 721 #ifdef OSI_EXPORT_DEBUG
 722         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): wrong parent 0x%08x/%d\n",
 723                parent->d_name.name ? (char *)parent->d_name.name : "?",
 724                data.fid.Cell,      data.fid.Fid.Volume,
 725                data.fid.Fid.Vnode, data.fid.Fid.Unique,
 726                vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume);
 727 #endif
 728         code = ENOENT;
 729         goto done;
 730     }
 731
 732
 733 redo:
 734     if (!(vcp->f.states & CStatd)) {
 735         if ((code = afs_VerifyVCache2(vcp, treq))) {
 736 #ifdef OSI_EXPORT_DEBUG
 737             printk("afs: get_name(%s, 0x%08x/%d/%d.%d): VerifyVCache2(0x%08x/%d/%d.%d): %d\n",
 738                    parent->d_name.name ? (char *)parent->d_name.name : "?",
 739                    data.fid.Cell,      data.fid.Fid.Volume,
 740                    data.fid.Fid.Vnode, data.fid.Fid.Unique,
 741                    vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 742                    vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique, code);
 743 #endif
 744             goto done;
 745         }
 746     }
 747
 748     tdc = afs_GetDCache(vcp, (afs_size_t) 0, treq, &dirOffset, &dirLen, 1);
 749     if (!tdc) {
 750 #ifdef OSI_EXPORT_DEBUG
 751         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): GetDCache(0x%08x/%d/%d.%d): %d\n",
 752                parent->d_name.name ? (char *)parent->d_name.name : "?",
 753                data.fid.Cell,      data.fid.Fid.Volume,
 754                data.fid.Fid.Vnode, data.fid.Fid.Unique,
 755                vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 756                vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique, code);
 757 #endif
 758         code = EIO;
 759         goto done;
 760     }
 761
 762     ObtainReadLock(&vcp->lock);
 763     ObtainReadLock(&tdc->lock);
 764
 765     /*
 766      * Make sure that the data in the cache is current. There are two
 767      * cases we need to worry about:
 768      * 1. The cache data is being fetched by another process.
 769      * 2. The cache data is no longer valid
 770      */
 771     while ((vcp->f.states & CStatd)
 772            && (tdc->dflags & DFFetching)
 773            && hsame(vcp->f.m.DataVersion, tdc->f.versionNo)) {
 774         ReleaseReadLock(&tdc->lock);
 775         ReleaseReadLock(&vcp->lock);
 776         afs_osi_Sleep(&tdc->validPos);
 777         ObtainReadLock(&vcp->lock);
 778         ObtainReadLock(&tdc->lock);
 779     }
 780     if (!(vcp->f.states & CStatd)
 781         || !hsame(vcp->f.m.DataVersion, tdc->f.versionNo)) {
 782         ReleaseReadLock(&tdc->lock);
 783         ReleaseReadLock(&vcp->lock);
 784         afs_PutDCache(tdc);
 785 #ifdef OSI_EXPORT_DEBUG
 786         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): dir (0x%08x/%d/%d.%d) changed; retrying\n",
 787                parent->d_name.name ? (char *)parent->d_name.name : "?",
 788                data.fid.Cell,      data.fid.Fid.Volume,
 789                data.fid.Fid.Vnode, data.fid.Fid.Unique,
 790                vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 791                vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique);
 792 #endif
 793         goto redo;
 794     }
 795
 796     data.name  = name;
 797     data.found = 0;
 798     code = afs_dir_EnumerateDir(tdc, get_name_hook, &data);
 799     if (!code && !data.found) {
 800 #ifdef OSI_EXPORT_DEBUG
 801         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): not found\n",
 802                parent->d_name.name ? (char *)parent->d_name.name : "?",
 803                data.fid.Cell,      data.fid.Fid.Volume,
 804                data.fid.Fid.Vnode, data.fid.Fid.Unique);
 805 #endif
 806         code = ENOENT;
 807     } else if (code) {
 808 #ifdef OSI_EXPORT_DEBUG
 809         printk("afs: get_name(%s, 0x%08x/%d/%d.%d): Enumeratedir(0x%08x/%d/%d.%d): %d\n",
 810                parent->d_name.name ? (char *)parent->d_name.name : "?",
 811                data.fid.Cell,      data.fid.Fid.Volume,
 812                data.fid.Fid.Vnode, data.fid.Fid.Unique,
 813                vcp->f.fid.Cell,      vcp->f.fid.Fid.Volume,
 814                vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique, code);
 815 #endif
 816     }
 817
 818     ReleaseReadLock(&tdc->lock);
 819     ReleaseReadLock(&vcp->lock);
 820     afs_PutDCache(tdc);
 821
 822 done:
 823     if (!code) {
 824         printk("afs: get_name(%s, 0x%08x/%d/%d.%d) => %s\n",
 825                parent->d_name.name ? (char *)parent->d_name.name : "?",
 826                data.fid.Cell,      data.fid.Fid.Volume,
 827                data.fid.Fid.Vnode, data.fid.Fid.Unique, name);
 828     }
 829     afs_PutFakeStat(&fakestate);
 830     code = afs_CheckCode(code, treq, 102);
 831     afs_DestroyReq(treq);
 832     AFS_GUNLOCK();
 833     crfree(credp);
 834     return -code;
 835 }
 836
 837
 838 static struct dentry *afs_export_get_parent(struct dentry *child)
 839 {
 840     struct VenusFid tfid;
 841     struct vrequest *treq = NULL;
 842     struct cell *tcell;
 843     struct vcache *vcp;
 844     struct dentry *dp = NULL;
 845     cred_t *credp;
 846     afs_uint32 cellidx;
 847     int code;
 848
 849     if (!child->d_inode) {
 850         /* can't find the parent of a negative dentry */
 851 #ifdef OSI_EXPORT_DEBUG
 852         printk("afs: get_parent(%s): no inode\n",
 853                child->d_name.name ? (char *)child->d_name.name : "?");
 854 #endif
 855         return ERR_PTR(-EIO);
 856     }
 857
 858     credp = crref();
 859     AFS_GLOCK();
 860
 861     vcp = VTOAFS(child->d_inode);
 862
 863     if (afs_IsDynrootMount(vcp)) {
 864         /* the dynmount directory; parent is always the AFS root */
 865         tfid = afs_globalVp->f.fid;
 866
 867     } else if (afs_IsDynrootAny(vcp) &&
 868                VNUM_TO_VNTYPE(vcp->f.fid.Fid.Vnode) == VN_TYPE_MOUNT) {
 869         /* a mount point in the dynmount directory */
 870         afs_GetDynrootMountFid(&tfid);
 871
 872     } else if (vcp->mvstat == AFS_MVSTAT_ROOT) {
 873         /* volume root */
 874         ObtainReadLock(&vcp->lock);
 875         if (vcp->mvid.parent && vcp->mvid.parent->Fid.Volume) {
 876             tfid = *vcp->mvid.parent;
 877             ReleaseReadLock(&vcp->lock);
 878         } else {
 879             ReleaseReadLock(&vcp->lock);
 880             tcell = afs_GetCell(vcp->f.fid.Cell, READ_LOCK);
 881             if (!tcell) {
 882 #ifdef OSI_EXPORT_DEBUG
 883                 printk("afs: get_parent(0x%08x/%d/%d.%d): no cell\n",
 884                        vcp->f.fid.Cell, vcp->f.fid.Fid.Volume,
 885                        vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique);
 886 #endif
 887                 dp = ERR_PTR(-ENOENT);
 888                 goto done;
 889             }
 890
 891             cellidx = tcell->cellIndex;
 892             afs_PutCell(tcell, READ_LOCK);
 893
 894             afs_GetDynrootMountFid(&tfid);
 895             tfid.Fid.Vnode = VNUM_FROM_TYPEID(VN_TYPE_MOUNT, cellidx << 2);
 896             tfid.Fid.Unique = vcp->f.fid.Fid.Volume;
 897         }
 898
 899     } else {
 900         /* any other vnode */
 901         if (vType(vcp) == VDIR && !vcp->f.parent.vnode && vcp->mvstat != AFS_MVSTAT_MTPT) {
 902             code = afs_CreateReq(&treq, credp);
 903             if (code) {
 904 #ifdef OSI_EXPORT_DEBUG
 905                 printk("afs: get_parent(0x%08x/%d/%d.%d): afs_CreateReq: %d\n",
 906                        vcp->f.fid.Cell, vcp->f.fid.Fid.Volume,
 907                        vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique, code);
 908 #endif
 909                 dp = ERR_PTR(-ENOENT);
 910                 goto done;
 911             } else {
 912                 code = update_dir_parent(treq, vcp);
 913                 if (code) {
 914 #ifdef OSI_EXPORT_DEBUG
 915                     printk("afs: get_parent(0x%08x/%d/%d.%d): update_dir_parent: %d\n",
 916                            vcp->f.fid.Cell, vcp->f.fid.Fid.Volume,
 917                            vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique, code);
 918 #endif
 919                     dp = ERR_PTR(-ENOENT);
 920                     goto done;
 921                 }
 922             }
 923         }
 924
 925         tfid.Cell       = vcp->f.fid.Cell;
 926         tfid.Fid.Volume = vcp->f.fid.Fid.Volume;
 927         tfid.Fid.Vnode  = vcp->f.parent.vnode;
 928         tfid.Fid.Unique = vcp->f.parent.unique;
 929     }
 930
 931 #ifdef OSI_EXPORT_DEBUG
 932     printk("afs: get_parent(0x%08x/%d/%d.%d): => 0x%08x/%d/%d.%d\n",
 933            vcp->f.fid.Cell, vcp->f.fid.Fid.Volume,
 934            vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique,
 935            tfid.Cell, tfid.Fid.Volume, tfid.Fid.Vnode, tfid.Fid.Unique);
 936 #endif
 937
 938     dp = get_dentry_from_fid(credp, &tfid);
 939     if (!dp) {
 940 #ifdef OSI_EXPORT_DEBUG
 941         printk("afs: get_parent(0x%08x/%d/%d.%d): no dentry\n",
 942                vcp->f.fid.Cell, vcp->f.fid.Fid.Volume,
 943                vcp->f.fid.Fid.Vnode, vcp->f.fid.Fid.Unique);
 944 #endif
 945         dp = ERR_PTR(-ENOENT);
 946     }
 947
 948 done:
 949     afs_DestroyReq(treq);
 950     AFS_GUNLOCK();
 951     crfree(credp);
 952
 953     return dp;
 954 }
 955
 956
 957 struct export_operations afs_export_ops = {
 958     .encode_fh  = afs_encode_fh,
 959 #if defined(NEW_EXPORT_OPS)
 960     .fh_to_dentry  = afs_fh_to_dentry,
 961 #else
 962     .decode_fh  = afs_decode_fh,
 963     .get_dentry = afs_export_get_dentry,
 964 #endif
 965     .get_name   = afs_export_get_name,
 966     .get_parent = afs_export_get_parent,
 967 };
 968
 969 #endif