src/afs/VNOPS/afs_vnop_remove.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  * Implements:
  12  * FetchWholeEnchilada
  13  * afsremove
  14  * afs_remove
  15  * afs_newname
  16  *
  17  */
  18 #include <afsconfig.h>
  19 #include "afs/param.h"
  20
  21
  22 #include "afs/sysincludes.h"    /* Standard vendor system headers */
  23 #include "afsincludes.h"        /* Afs-based standard headers */
  24 #include "afs/afs_stats.h"      /* statistics */
  25 #include "afs/afs_cbqueue.h"
  26 #include "afs/nfsclient.h"
  27 #include "afs/afs_osidnlc.h"
  28
  29
  30 extern afs_rwlock_t afs_xvcache;
  31 extern afs_rwlock_t afs_xcbhash;
  32
  33
  34 static void
  35 FetchWholeEnchilada(struct vcache *avc, struct vrequest *areq)
  36 {
  37     afs_int32 nextChunk;
  38     struct dcache *tdc;
  39     afs_size_t pos, offset, len;
  40
  41     AFS_STATCNT(FetchWholeEnchilada);
  42     if ((avc->f.states & CStatd) == 0)
  43         return;                 /* don't know size */
  44     for (nextChunk = 0; nextChunk < 1024; nextChunk++) {        /* sanity check on N chunks */
  45         pos = AFS_CHUNKTOBASE(nextChunk);
  46         if (pos >= avc->f.m.Length)
  47             return;             /* all done */
  48         tdc = afs_GetDCache(avc, pos, areq, &offset, &len, 0);
  49         if (!tdc)
  50             return;
  51         afs_PutDCache(tdc);
  52     }
  53 }
  54
  55 int
  56 afsremove(struct vcache *adp, struct dcache *tdc,
  57           struct vcache *tvc, char *aname, afs_ucred_t *acred,
  58           struct vrequest *treqp)
  59 {
  60     afs_int32 code = 0;
  61     struct afs_conn *tc;
  62     struct AFSFetchStatus OutDirStatus;
  63     struct AFSVolSync tsync;
  64     struct rx_connection *rxconn;
  65     XSTATS_DECLS;
  66     if (!AFS_IS_DISCONNECTED) {
  67         do {
  68             tc = afs_Conn(&adp->f.fid, treqp, SHARED_LOCK, &rxconn);
  69             if (tc) {
  70                 XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_REMOVEFILE);
  71                 RX_AFS_GUNLOCK();
  72                 code =
  73                     RXAFS_RemoveFile(rxconn, (struct AFSFid *)&adp->f.fid.Fid,
  74                                      aname, &OutDirStatus, &tsync);
  75                 RX_AFS_GLOCK();
  76                 XSTATS_END_TIME;
  77             } else
  78                 code = -1;
  79         } while (afs_Analyze
  80                  (tc, rxconn, code, &adp->f.fid, treqp, AFS_STATS_FS_RPCIDX_REMOVEFILE,
  81                   SHARED_LOCK, NULL));
  82     }
  83
  84     osi_dnlc_remove(adp, aname, tvc);
  85
  86     if (code) {
  87         if (tdc) {
  88             ReleaseSharedLock(&tdc->lock);
  89             afs_PutDCache(tdc);
  90         }
  91
  92         if (tvc)
  93             afs_PutVCache(tvc);
  94
  95         if (code < 0) {
  96             afs_StaleVCache(adp);
  97         }
  98         ReleaseWriteLock(&adp->lock);
  99         code = afs_CheckCode(code, treqp, 21);
 100         return code;
 101     }
 102     if (tdc)
 103         UpgradeSToWLock(&tdc->lock, 637);
 104     if (AFS_IS_DISCON_RW || afs_LocalHero(adp, tdc, &OutDirStatus, 1)) {
 105         /* we can do it locally */
 106         code = afs_dir_Delete(tdc, aname);
 107         if (code) {
 108             ZapDCE(tdc);        /* surprise error -- invalid value */
 109             DZap(tdc);
 110         }
 111     }
 112     if (tdc) {
 113         ReleaseWriteLock(&tdc->lock);
 114         afs_PutDCache(tdc);     /* drop ref count */
 115     }
 116     ReleaseWriteLock(&adp->lock);
 117
 118     /* now, get vnode for unlinked dude, and see if we should force it
 119      * from cache.  adp is now the deleted files vnode.  Note that we
 120      * call FindVCache instead of GetVCache since if the file's really
 121      * gone, we won't be able to fetch the status info anyway.  */
 122     if (tvc) {
 123         if (afs_mariner)
 124             afs_MarinerLog("store$Removing", tvc);
 125         ObtainWriteLock(&tvc->lock, 141);
 126         /* note that callback will be broken on the deleted file if there are
 127          * still >0 links left to it, so we'll get the stat right */
 128         tvc->f.m.LinkCount--;
 129         tvc->f.states &= ~CUnique;      /* For the dfs xlator */
 130         if (tvc->f.m.LinkCount == 0 && !osi_Active(tvc)) {
 131             if (!AFS_NFSXLATORREQ(acred))
 132                 afs_TryToSmush(tvc, acred, 0);
 133         }
 134         ReleaseWriteLock(&tvc->lock);
 135         afs_PutVCache(tvc);
 136     }
 137     return (0);
 138 }
 139
 140 char *
 141 afs_newname(void)
 142 {
 143     char *name, *sp, *p = ".__afs";
 144     afs_int32 rd = afs_random() & 0xffff;
 145
 146     sp = name = osi_AllocSmallSpace(AFS_SMALLOCSIZ);
 147     while (*p != '\0')
 148         *sp++ = *p++;
 149     while (rd) {
 150         *sp++ = "0123456789ABCDEF"[rd & 0x0f];
 151         rd >>= 4;
 152     }
 153     *sp = '\0';
 154     return (name);
 155 }
 156
 157 /* these variables appear to exist for debugging purposes */
 158 struct vcache *Tadp1, *Ttvc;
 159 int Tadpr, Ttvcr;
 160 char *Tnam;
 161 char *Tnam1;
 162
 163 /* Note that we don't set CDirty here, this is OK because the unlink
 164  * RPC is called synchronously */
 165 int
 166 afs_remove(OSI_VC_DECL(adp), char *aname, afs_ucred_t *acred)
 167 {
 168     struct vrequest *treq = NULL;
 169     struct dcache *tdc;
 170     struct VenusFid unlinkFid;
 171     afs_int32 code;
 172     struct vcache *tvc;
 173     afs_size_t offset, len;
 174     struct afs_fakestat_state fakestate;
 175     OSI_VC_CONVERT(adp);
 176
 177     AFS_STATCNT(afs_remove);
 178     afs_Trace2(afs_iclSetp, CM_TRACE_REMOVE, ICL_TYPE_POINTER, adp,
 179                ICL_TYPE_STRING, aname);
 180
 181
 182     if ((code = afs_CreateReq(&treq, acred))) {
 183         return code;
 184     }
 185
 186     afs_InitFakeStat(&fakestate);
 187     AFS_DISCON_LOCK();
 188     code = afs_EvalFakeStat(&adp, &fakestate, treq);
 189     if (code)
 190         goto done;
 191
 192     /* Check if this is dynroot */
 193     if (afs_IsDynroot(adp)) {
 194         code = afs_DynrootVOPRemove(adp, acred, aname);
 195         goto done;
 196     }
 197     if (afs_IsDynrootMount(adp)) {
 198         code = EROFS;
 199         goto done;
 200     }
 201
 202     if (strlen(aname) > AFSNAMEMAX) {
 203         code = ENAMETOOLONG;
 204         goto done;
 205     }
 206   tagain:
 207     code = afs_VerifyVCache(adp, treq);
 208     tvc = NULL;
 209     if (code) {
 210         code = afs_CheckCode(code, treq, 23);
 211         goto done;
 212     }
 213
 214     /** If the volume is read-only, return error without making an RPC to the
 215       * fileserver
 216       */
 217     if (adp->f.states & CRO) {
 218         code = EROFS;
 219         goto done;
 220     }
 221
 222     /* If we're running disconnected without logging, go no further... */
 223     if (AFS_IS_DISCONNECTED && !AFS_IS_DISCON_RW) {
 224         code = ENETDOWN;
 225         goto done;
 226     }
 227
 228     tdc = afs_GetDCache(adp, (afs_size_t) 0, treq, &offset, &len, 1);   /* test for error below */
 229     ObtainWriteLock(&adp->lock, 142);
 230     if (tdc)
 231         ObtainSharedLock(&tdc->lock, 638);
 232
 233     /*
 234      * Make sure that the data in the cache is current. We may have
 235      * received a callback while we were waiting for the write lock.
 236      */
 237     if (!(adp->f.states & CStatd)
 238         || (tdc && !hsame(adp->f.m.DataVersion, tdc->f.versionNo))) {
 239         ReleaseWriteLock(&adp->lock);
 240         if (tdc) {
 241             ReleaseSharedLock(&tdc->lock);
 242             afs_PutDCache(tdc);
 243         }
 244         goto tagain;
 245     }
 246
 247     unlinkFid.Fid.Vnode = 0;
 248     if (!tvc) {
 249         tvc = osi_dnlc_lookup(adp, aname, WRITE_LOCK);
 250     }
 251     /* This should not be necessary since afs_lookup() has already
 252      * done the work.
 253      */
 254     if (!tvc)
 255         if (tdc) {
 256             code = afs_dir_Lookup(tdc, aname, &unlinkFid.Fid);
 257             if (code == 0) {
 258                 afs_int32 cached = 0;
 259
 260                 unlinkFid.Cell = adp->f.fid.Cell;
 261                 unlinkFid.Fid.Volume = adp->f.fid.Fid.Volume;
 262                 if (unlinkFid.Fid.Unique == 0) {
 263                     tvc =
 264                         afs_LookupVCache(&unlinkFid, treq, &cached, adp,
 265                                          aname);
 266                 } else {
 267                     ObtainReadLock(&afs_xvcache);
 268                     tvc = afs_FindVCache(&unlinkFid, 0, DO_STATS);
 269                     ReleaseReadLock(&afs_xvcache);
 270                 }
 271             }
 272         }
 273
 274     if (AFS_IS_DISCON_RW) {
 275         if (!adp->f.shadow.vnode && !(adp->f.ddirty_flags & VDisconCreate)) {
 276             /* Make shadow copy of parent dir. */
 277             afs_MakeShadowDir(adp, tdc);
 278         }
 279
 280         /* Can't hold a dcache lock whilst we're getting a vcache one */
 281         if (tdc)
 282             ReleaseSharedLock(&tdc->lock);
 283
 284         /* XXX - We're holding adp->lock still, and we've got no
 285          * guarantee about whether the ordering matches the lock hierarchy */
 286         ObtainWriteLock(&tvc->lock, 713);
 287
 288         /* If we were locally created, then we don't need to do very
 289          * much beyond ensuring that we don't exist anymore */
 290         if (tvc->f.ddirty_flags & VDisconCreate) {
 291             afs_DisconRemoveDirty(tvc);
 292         } else {
 293             /* Add removed file vcache to dirty list. */
 294             afs_DisconAddDirty(tvc, VDisconRemove, 1);
 295         }
 296         adp->f.m.LinkCount--;
 297         ReleaseWriteLock(&tvc->lock);
 298         if (tdc)
 299             ObtainSharedLock(&tdc->lock, 714);
 300      }
 301
 302     if (tvc && osi_Active(tvc)) {
 303         /* about to delete whole file, prefetch it first */
 304         ReleaseWriteLock(&adp->lock);
 305         if (tdc)
 306             ReleaseSharedLock(&tdc->lock);
 307         ObtainWriteLock(&tvc->lock, 143);
 308         FetchWholeEnchilada(tvc, treq);
 309         ReleaseWriteLock(&tvc->lock);
 310         ObtainWriteLock(&adp->lock, 144);
 311         /* Technically I don't think we need this back, but let's hold it
 312            anyway; The "got" reference should actually be sufficient. */
 313         if (tdc)
 314             ObtainSharedLock(&tdc->lock, 640);
 315     }
 316
 317     osi_dnlc_remove(adp, aname, tvc);
 318
 319     Tadp1 = adp;
 320 #ifndef AFS_DARWIN80_ENV
 321     Tadpr = VREFCOUNT(adp);
 322 #endif
 323     Ttvc = tvc;
 324     Tnam = aname;
 325     Tnam1 = 0;
 326 #ifndef AFS_DARWIN80_ENV
 327     if (tvc)
 328         Ttvcr = VREFCOUNT(tvc);
 329 #endif
 330 #ifdef  AFS_AIX_ENV
 331     if (tvc && VREFCOUNT_GT(tvc, 2) && tvc->opens > 0
 332         && !(tvc->f.states & CUnlinked)) {
 333 #else
 334     if (tvc && VREFCOUNT_GT(tvc, 1) && tvc->opens > 0
 335         && !(tvc->f.states & CUnlinked)) {
 336 #endif
 337         char *unlname = afs_newname();
 338
 339         ReleaseWriteLock(&adp->lock);
 340         if (tdc)
 341             ReleaseSharedLock(&tdc->lock);
 342         code = afsrename(adp, aname, adp, unlname, acred, treq);
 343         Tnam1 = unlname;
 344         if (!code) {
 345             void *oldmvid = NULL;
 346             if (tvc->mvid.silly_name)
 347                 oldmvid = tvc->mvid.silly_name;
 348             tvc->mvid.silly_name = unlname;
 349             if (oldmvid)
 350                 osi_FreeSmallSpace(oldmvid);
 351             crhold(acred);
 352             if (tvc->uncred) {
 353                 crfree(tvc->uncred);
 354             }
 355             tvc->uncred = acred;
 356             tvc->f.states |= CUnlinked;
 357             /* if rename succeeded, remove should not */
 358             ObtainWriteLock(&tvc->lock, 715);
 359             if (tvc->f.ddirty_flags & VDisconRemove) {
 360                 tvc->f.ddirty_flags &= ~VDisconRemove;
 361             }
 362             ReleaseWriteLock(&tvc->lock);
 363         } else {
 364             osi_FreeSmallSpace(unlname);
 365         }
 366         if (tdc)
 367             afs_PutDCache(tdc);
 368         afs_PutVCache(tvc);
 369     } else {
 370         code = afsremove(adp, tdc, tvc, aname, acred, treq);
 371     }
 372     done:
 373     afs_PutFakeStat(&fakestate);
 374 #if !defined(AFS_DARWIN80_ENV) && !defined(UKERNEL)
 375     /* we can't track by thread, it's not exported in the KPI; only do
 376        this on !macos */
 377     osi_Assert(!WriteLocked(&adp->lock) || (adp->lock.pid_writer != MyPidxx));
 378 #endif
 379     AFS_DISCON_UNLOCK();
 380     afs_DestroyReq(treq);
 381     return code;
 382 }
 383
 384
 385 /* afs_remunlink -- This tries to delete the file at the server after it has
 386  *     been renamed when unlinked locally but now has been finally released.
 387  *
 388  * CAUTION -- may be called with avc unheld. */
 389
 390 int
 391 afs_remunlink(struct vcache *avc, int doit)
 392 {
 393     afs_ucred_t *cred;
 394     char *unlname;
 395     struct vcache *adp;
 396     struct VenusFid dirFid;
 397     struct dcache *tdc;
 398     afs_int32 code = 0;
 399
 400     if (NBObtainWriteLock(&avc->lock, 423))
 401         return 0;
 402 #if defined(AFS_DARWIN80_ENV)
 403     if (vnode_get(AFSTOV(avc))) {
 404         ReleaseWriteLock(&avc->lock);
 405         return 0;
 406     }
 407 #endif
 408
 409     if (avc->mvid.silly_name && (doit || (avc->f.states & CUnlinkedDel))) {
 410         struct vrequest *treq = NULL;
 411
 412         if ((code = afs_CreateReq(&treq, avc->uncred))) {
 413             ReleaseWriteLock(&avc->lock);
 414         } else {
 415             /* Must bump the refCount because GetVCache may block.
 416              * Also clear mvid so no other thread comes here if we block.
 417              */
 418             unlname = avc->mvid.silly_name;
 419             avc->mvid.silly_name = NULL;
 420             cred = avc->uncred;
 421             avc->uncred = NULL;
 422
 423 #if defined(AFS_DARWIN_ENV) && !defined(AFS_DARWIN80_ENV)
 424             VREF(AFSTOV(avc));
 425 #else
 426             AFS_FAST_HOLD(avc);
 427 #endif
 428
 429             /* We'll only try this once. If it fails, just release the vnode.
 430              * Clear after doing hold so that NewVCache doesn't find us yet.
 431              */
 432             avc->f.states &= ~(CUnlinked | CUnlinkedDel);
 433
 434             ReleaseWriteLock(&avc->lock);
 435
 436             dirFid.Cell = avc->f.fid.Cell;
 437             dirFid.Fid.Volume = avc->f.fid.Fid.Volume;
 438             dirFid.Fid.Vnode = avc->f.parent.vnode;
 439             dirFid.Fid.Unique = avc->f.parent.unique;
 440             adp = afs_GetVCache(&dirFid, treq, NULL, NULL);
 441
 442             if (adp) {
 443                 tdc = afs_FindDCache(adp, (afs_size_t) 0);
 444                 ObtainWriteLock(&adp->lock, 159);
 445                 if (tdc)
 446                     ObtainSharedLock(&tdc->lock, 639);
 447
 448                 /* afsremove releases the adp & tdc locks, and does vn_rele(avc) */
 449                 code = afsremove(adp, tdc, avc, unlname, cred, treq);
 450                 afs_PutVCache(adp);
 451             } else {
 452                 /* we failed - and won't be back to try again. */
 453                 afs_PutVCache(avc);
 454             }
 455             osi_FreeSmallSpace(unlname);
 456             crfree(cred);
 457             afs_DestroyReq(treq);
 458         }
 459     } else {
 460 #if defined(AFS_DARWIN80_ENV)
 461         vnode_put(AFSTOV(avc));
 462 #endif
 463         ReleaseWriteLock(&avc->lock);
 464     }
 465
 466     return code;
 467 }