int
DRead(struct dcache *adc, int page, struct DirBuffer *entry)
{
    /* Read a page from the disk. */
    struct buffer *tb, *tb2;
    struct osi_file *tfile;
    int code;

    AFS_STATCNT(DRead);

    memset(entry, 0, sizeof(struct DirBuffer));

    ObtainWriteLock(&afs_bufferLock, 256);

#define bufmatch(tb) (tb->page == page && tb->fid == adc->index)
#define buf_Front(head,parent,p) {(parent)->hashNext = (p)->hashNext; (p)->hashNext= *(head);*(head)=(p);}

    /* this apparently-complicated-looking code is simply an example of
     * a little bit of loop unrolling, and is a standard linked-list
     * traversal trick. It saves a few assignments at the the expense
     * of larger code size.  This could be simplified by better use of
     * macros.
     */
    if ((tb = phTable[pHash(adc->index, page)])) {
	if (bufmatch(tb)) {
	    ObtainWriteLock(&tb->lock, 257);
	    tb->lockers++;
	    ReleaseWriteLock(&afs_bufferLock);
	    tb->accesstime = timecounter++;
	    AFS_STATS(afs_stats_cmperf.bufHits++);
	    ReleaseWriteLock(&tb->lock);
	    entry->buffer = tb;
	    entry->data = tb->data;
	    return 0;
	} else {
	    struct buffer **bufhead;
	    bufhead = &(phTable[pHash(adc->index, page)]);
	    while ((tb2 = tb->hashNext)) {
		if (bufmatch(tb2)) {
		    buf_Front(bufhead, tb, tb2);
		    ObtainWriteLock(&tb2->lock, 258);
		    tb2->lockers++;
		    ReleaseWriteLock(&afs_bufferLock);
		    tb2->accesstime = timecounter++;
		    AFS_STATS(afs_stats_cmperf.bufHits++);
		    ReleaseWriteLock(&tb2->lock);
		    entry->buffer = tb2;
		    entry->data = tb2->data;
		    return 0;
		}
		if ((tb = tb2->hashNext)) {
		    if (bufmatch(tb)) {
			buf_Front(bufhead, tb2, tb);
			ObtainWriteLock(&tb->lock, 259);
			tb->lockers++;
			ReleaseWriteLock(&afs_bufferLock);
			tb->accesstime = timecounter++;
			AFS_STATS(afs_stats_cmperf.bufHits++);
			ReleaseWriteLock(&tb->lock);
			entry->buffer = tb;
			entry->data = tb->data;
			return 0;
		    }
		} else
		    break;
	    }
	}
    } else
	tb2 = NULL;

    AFS_STATS(afs_stats_cmperf.bufMisses++);
    /* can't find it */
    /* The last thing we looked at was either tb or tb2 (or nothing). That
     * is at least the oldest buffer on one particular hash chain, so it's
     * a pretty good place to start looking for the truly oldest buffer.
     */
    tb = afs_newslot(adc, page, (tb ? tb : tb2));
    if (!tb) {
	ReleaseWriteLock(&afs_bufferLock);
	return EIO;
    }
    ObtainWriteLock(&tb->lock, 260);
    tb->lockers++;
    ReleaseWriteLock(&afs_bufferLock);
    if (page * AFS_BUFFER_PAGESIZE >= adc->f.chunkBytes) {
	tb->fid = NULLIDX;
	afs_reset_inode(&tb->inode);
	tb->lockers--;
	ReleaseWriteLock(&tb->lock);
	return EIO;
    }
    tfile = afs_CFileOpen(&adc->f.inode);
    code =
	afs_CFileRead(tfile, tb->page * AFS_BUFFER_PAGESIZE, tb->data,
		      AFS_BUFFER_PAGESIZE);
    afs_CFileClose(tfile);
    if (code < AFS_BUFFER_PAGESIZE) {
	tb->fid = NULLIDX;
	afs_reset_inode(&tb->inode);
	tb->lockers--;
//.........这里部分代码省略.........

/*
 * afs_TruncateAllSegments
 *
 * Description:
 *	Truncate a cache file.
 *
 * Parameters:
 *	avc  : Ptr to vcache entry to truncate.
 *	alen : Number of bytes to make the file.
 *	areq : Ptr to request structure.
 *
 * Environment:
 *	Called with avc write-locked; in VFS40 systems, pvnLock is also
 *	held.
 */
int
afs_TruncateAllSegments(struct vcache *avc, afs_size_t alen,
			struct vrequest *areq, afs_ucred_t *acred)
{
    struct dcache *tdc;
    afs_int32 code;
    afs_int32 index;
    afs_size_t newSize;

    int dcCount, dcPos;
    struct dcache **tdcArray = NULL;

    AFS_STATCNT(afs_TruncateAllSegments);
    avc->f.m.Date = osi_Time();
    afs_Trace3(afs_iclSetp, CM_TRACE_TRUNCALL, ICL_TYPE_POINTER, avc,
	       ICL_TYPE_OFFSET, ICL_HANDLE_OFFSET(avc->f.m.Length),
	       ICL_TYPE_OFFSET, ICL_HANDLE_OFFSET(alen));
    if (alen >= avc->f.m.Length) {
	/*
	 * Special speedup since Sun's vm extends the file this way;
	 * we've never written to the file thus we can just set the new
	 * length and avoid the needless calls below.
	 * Also used for ftruncate calls which can extend the file.
	 * To completely minimize the possible extra StoreMini RPC, we really
	 * should keep the ExtendedPos as well and clear this flag if we
	 * truncate below that value before we store the file back.
	 */
	avc->f.states |= CExtendedFile;
	avc->f.m.Length = alen;
	return 0;
    }
#if	(defined(AFS_SUN5_ENV))

    /* Zero unused portion of last page */
    osi_VM_PreTruncate(avc, alen, acred);

#endif

#if	(defined(AFS_SUN5_ENV))
    ObtainWriteLock(&avc->vlock, 546);
    avc->activeV++;		/* Block new getpages */
    ReleaseWriteLock(&avc->vlock);
#endif

    ReleaseWriteLock(&avc->lock);
    AFS_GUNLOCK();

    /* Flush pages beyond end-of-file. */
    osi_VM_Truncate(avc, alen, acred);

    AFS_GLOCK();
    ObtainWriteLock(&avc->lock, 79);

    avc->f.m.Length = alen;

    if (alen < avc->f.truncPos)
	avc->f.truncPos = alen;
    code = DVHash(&avc->f.fid);

    /* block out others from screwing with this table */
    ObtainWriteLock(&afs_xdcache, 287);

    dcCount = 0;
    for (index = afs_dvhashTbl[code]; index != NULLIDX;) {
	if (afs_indexUnique[index] == avc->f.fid.Fid.Unique) {
	    tdc = afs_GetValidDSlot(index);
	    if (!tdc) {
		ReleaseWriteLock(&afs_xdcache);
		code = EIO;
		goto done;
	    }
	    ReleaseReadLock(&tdc->tlock);
	    if (!FidCmp(&tdc->f.fid, &avc->f.fid))
		dcCount++;
	    afs_PutDCache(tdc);
	}
	index = afs_dvnextTbl[index];
    }

    /* Now allocate space where we can save those dcache entries, and
     * do a second pass over them..  Since we're holding xdcache, it
     * shouldn't be changing.
     */
    tdcArray = osi_Alloc(dcCount * sizeof(struct dcache *));
    dcPos = 0;
//.........这里部分代码省略.........

void *
osi_UFSOpen(afs_dcache_id_t *ainode)
{
    struct vnode *vp;
    struct vattr va;
    struct osi_file *afile = NULL;
    extern int cacheDiskType;
    afs_int32 code = 0;
    int dummy;
    char fname[1024];
    struct osi_stat tstat;

    AFS_STATCNT(osi_UFSOpen);
    if (cacheDiskType != AFS_FCACHE_TYPE_UFS) {
	osi_Panic("UFSOpen called for non-UFS cache\n");
    }
    if (!afs_osicred_initialized) {
	/* valid for alpha_osf, SunOS, Ultrix */
	memset(&afs_osi_cred, 0, sizeof(afs_ucred_t));
	afs_osi_cred.cr_ref++;
#ifndef AFS_DARWIN110_ENV
	afs_osi_cred.cr_ngroups = 1;
#endif
	afs_osicred_initialized = 1;
    }
    afile = (struct osi_file *)osi_AllocSmallSpace(sizeof(struct osi_file));
    AFS_GUNLOCK();
#ifdef AFS_CACHE_VNODE_PATH
    if (!ainode->ufs) {
	osi_Panic("No cache inode\n");
    }

    code = vnode_open(ainode->ufs, O_RDWR, 0, 0, &vp, afs_osi_ctxtp);
#else
#ifndef AFS_DARWIN80_ENV
    if (afs_CacheFSType == AFS_APPL_HFS_CACHE)
	code = igetinode(afs_cacheVfsp, (dev_t) cacheDev.dev, &ainode->ufs, &vp, &va, &dummy);	/* XXX hfs is broken */
    else if (afs_CacheFSType == AFS_APPL_UFS_CACHE)
#endif
	code =
	    igetinode(afs_cacheVfsp, (dev_t) cacheDev.dev, (ino_t) ainode->ufs,
		      &vp, &va, &dummy);
#ifndef AFS_DARWIN80_ENV
    else
	panic("osi_UFSOpen called before cacheops initialized\n");
#endif
#endif
    AFS_GLOCK();
    if (code) {
	osi_FreeSmallSpace(afile);
	osi_Panic("UFSOpen: igetinode failed");
    }
    afile->vnode = vp;
    afile->offset = 0;
    afile->proc = (int (*)())0;
#ifndef AFS_CACHE_VNODE_PATH
    afile->size = va.va_size;
#else
    code = afs_osi_Stat(afile, &tstat);
    afile->size = tstat.size;
#endif
    return (void *)afile;
}

/* free socket allocated by osi_NetSocket */
int
rxk_FreeSocket(struct socket *asocket)
{
    AFS_STATCNT(osi_FreeSocket);
    return 0;
}

static int
afs_StoreMini(struct vcache *avc, struct vrequest *areq)
{
    struct afs_conn *tc;
    struct AFSStoreStatus InStatus;
    struct AFSFetchStatus OutStatus;
    struct AFSVolSync tsync;
    afs_int32 code;
    struct rx_call *tcall;
    struct rx_connection *rxconn;
    afs_size_t tlen, xlen = 0;
    XSTATS_DECLS;
    AFS_STATCNT(afs_StoreMini);
    afs_Trace2(afs_iclSetp, CM_TRACE_STOREMINI, ICL_TYPE_POINTER, avc,
	       ICL_TYPE_INT32, avc->f.m.Length);
    tlen = avc->f.m.Length;
    if (avc->f.truncPos < tlen)
	tlen = avc->f.truncPos;
    avc->f.truncPos = AFS_NOTRUNC;
    avc->f.states &= ~CExtendedFile;

    do {
	tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK, &rxconn);
	if (tc) {
#ifdef AFS_64BIT_CLIENT
	  retry:
#endif
	    RX_AFS_GUNLOCK();
	    tcall = rx_NewCall(rxconn);
	    RX_AFS_GLOCK();
	    /* Set the client mod time since we always want the file
	     * to have the client's mod time and not the server's one
	     * (to avoid problems with make, etc.) It almost always
	     * works fine with standard afs because them server/client
	     * times are in sync and more importantly this storemini
	     * it's a special call that would typically be followed by
	     * the proper store-data or store-status calls.
	     */
	    InStatus.Mask = AFS_SETMODTIME;
	    InStatus.ClientModTime = avc->f.m.Date;
	    XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_STOREDATA);
	    afs_Trace4(afs_iclSetp, CM_TRACE_STOREDATA64, ICL_TYPE_FID,
		       &avc->f.fid.Fid, ICL_TYPE_OFFSET,
		       ICL_HANDLE_OFFSET(avc->f.m.Length), ICL_TYPE_OFFSET,
		       ICL_HANDLE_OFFSET(xlen), ICL_TYPE_OFFSET,
		       ICL_HANDLE_OFFSET(tlen));
	    RX_AFS_GUNLOCK();
#ifdef AFS_64BIT_CLIENT
	    if (!afs_serverHasNo64Bit(tc)) {
		code =
		    StartRXAFS_StoreData64(tcall,
					   (struct AFSFid *)&avc->f.fid.Fid,
					   &InStatus, avc->f.m.Length,
					   (afs_size_t) 0, tlen);
	    } else {
		afs_int32 l1, l2;
		l1 = avc->f.m.Length;
		l2 = tlen;
		if ((avc->f.m.Length > 0x7fffffff) ||
		    (tlen > 0x7fffffff) ||
		    ((0x7fffffff - tlen) < avc->f.m.Length)) {
		    code = EFBIG;
		    goto error;
		}
		code =
		    StartRXAFS_StoreData(tcall,
					 (struct AFSFid *)&avc->f.fid.Fid,
					 &InStatus, l1, 0, l2);
	    }
#else /* AFS_64BIT_CLIENT */
	    code =
		StartRXAFS_StoreData(tcall, (struct AFSFid *)&avc->f.fid.Fid,
				     &InStatus, avc->f.m.Length, 0, tlen);
#endif /* AFS_64BIT_CLIENT */
	    if (code == 0) {
		code = EndRXAFS_StoreData(tcall, &OutStatus, &tsync);
	    }
#ifdef AFS_64BIT_CLIENT
	error:
#endif
	    code = rx_EndCall(tcall, code);
	    RX_AFS_GLOCK();
	    XSTATS_END_TIME;
#ifdef AFS_64BIT_CLIENT
	    if (code == RXGEN_OPCODE && !afs_serverHasNo64Bit(tc)) {
		afs_serverSetNo64Bit(tc);
		goto retry;
	    }
#endif /* AFS_64BIT_CLIENT */
	} else
	    code = -1;
    } while (afs_Analyze
	     (tc, rxconn, code, &avc->f.fid, areq, AFS_STATS_FS_RPCIDX_STOREDATA,
	      SHARED_LOCK, NULL));

    if (code == 0)
	afs_ProcessFS(avc, &OutStatus, areq);

    return code;
}				/*afs_StoreMini */

int
afs_sync(struct vfs *afsp)
{
    AFS_STATCNT(afs_sync);
    return 0;
}

afs_open(struct vcache **avcp, afs_int32 aflags, afs_ucred_t *acred)
#endif
{
    afs_int32 code;
    struct vrequest treq;
    struct vcache *tvc;
    int writing;
    struct afs_fakestat_state fakestate;

    AFS_STATCNT(afs_open);
    if ((code = afs_InitReq(&treq, acred)))
	return code;
#ifdef AFS_SGI64_ENV
    /* avcpp can be, but is not necesarily, bhp's vnode. */
    tvc = VTOAFS(BHV_TO_VNODE(bhv));
#else
    tvc = *avcp;
#endif
    afs_Trace2(afs_iclSetp, CM_TRACE_OPEN, ICL_TYPE_POINTER, tvc,
	       ICL_TYPE_INT32, aflags);
    afs_InitFakeStat(&fakestate);

    AFS_DISCON_LOCK();

    code = afs_EvalFakeStat(&tvc, &fakestate, &treq);
    if (code)
	goto done;
    code = afs_VerifyVCache(tvc, &treq);
    if (code)
	goto done;

    ObtainReadLock(&tvc->lock);

    if (AFS_IS_DISCONNECTED && (afs_DCacheMissingChunks(tvc) != 0)) {
       ReleaseReadLock(&tvc->lock);
       /* printf("Network is down in afs_open: missing chunks\n"); */
       code = ENETDOWN;
       goto done;
    }

    ReleaseReadLock(&tvc->lock);

    if (aflags & (FWRITE | FTRUNC))
	writing = 1;
    else
	writing = 0;
    if (vType(tvc) == VDIR) {
	/* directory */
	if (writing) {
	    code = EISDIR;
	    goto done;
	} else {
	    if (!afs_AccessOK
		(tvc, ((tvc->f.states & CForeign) ? PRSFS_READ : PRSFS_LOOKUP),
		 &treq, CHECK_MODE_BITS)) {
		code = EACCES;
		/* printf("afs_Open: no access for dir\n"); */
		goto done;
	    }
	}
    } else {
#ifdef	AFS_SUN5_ENV
	if (AFS_NFSXLATORREQ(acred) && (aflags & FREAD)) {
	    if (!afs_AccessOK
		(tvc, PRSFS_READ, &treq,
		 CHECK_MODE_BITS | CMB_ALLOW_EXEC_AS_READ)) {
		code = EACCES;
		goto done;
	    }
	}
#endif
#ifdef	AFS_AIX41_ENV
	if (aflags & FRSHARE) {
	    /*
	     * Hack for AIX 4.1:
	     *  Apparently it is possible for a file to get mapped without
	     *  either VNOP_MAP or VNOP_RDWR being called, if (1) it is a
	     *  sharable library, and (2) it has already been loaded.  We must
	     *  ensure that the credp is up to date.  We detect the situation
	     *  by checking for O_RSHARE at open time.
	     */
	    /*
	     * We keep the caller's credentials since an async daemon will
	     * handle the request at some point. We assume that the same
	     * credentials will be used.
	     */
	    ObtainWriteLock(&tvc->lock, 140);
	    if (!tvc->credp || (tvc->credp != acred)) {
		crhold(acred);
		if (tvc->credp) {
		    struct ucred *crp = tvc->credp;
		    tvc->credp = NULL;
		    crfree(crp);
		}
		tvc->credp = acred;
	    }
	    ReleaseWriteLock(&tvc->lock);
	}
#endif
	/* normal file or symlink */
//.........这里部分代码省略.........

int afspag_PSetTokens(char *ain, afs_int32 ainSize, struct AFS_UCRED **acred)
{
    afs_int32 i;
    register struct unixuser *tu;
    struct afspag_cell *tcell;
    struct ClearToken clear;
    char *stp;
    int stLen;
    afs_int32 flag, set_parent_pag = 0;
    afs_int32 pag, uid;

    AFS_STATCNT(PSetTokens);
    if (!afs_resourceinit_flag) {
	return EIO;
    }
    memcpy((char *)&i, ain, sizeof(afs_int32));
    ain += sizeof(afs_int32);
    stp = ain;			/* remember where the ticket is */
    if (i < 0 || i > MAXKTCTICKETLEN)
	return EINVAL;		/* malloc may fail */
    stLen = i;
    ain += i;			/* skip over ticket */
    memcpy((char *)&i, ain, sizeof(afs_int32));
    ain += sizeof(afs_int32);
    if (i != sizeof(struct ClearToken)) {
	return EINVAL;
    }
    memcpy((char *)&clear, ain, sizeof(struct ClearToken));
    if (clear.AuthHandle == -1)
	clear.AuthHandle = 999;	/* more rxvab compat stuff */
    ain += sizeof(struct ClearToken);
    if (ainSize != 2 * sizeof(afs_int32) + stLen + sizeof(struct ClearToken)) {
	/* still stuff left?  we've got primary flag and cell name.  Set these */
	memcpy((char *)&flag, ain, sizeof(afs_int32));	/* primary id flag */
	ain += sizeof(afs_int32);	/* skip id field */
	/* rest is cell name, look it up */
	/* some versions of gcc appear to need != 0 in order to get this right */
	if ((flag & 0x8000) != 0) {	/* XXX Use Constant XXX */
	    flag &= ~0x8000;
	    set_parent_pag = 1;
	}
	tcell = afspag_GetCell(ain);
    } else {
	/* default to primary cell, primary id */
	flag = 1;		/* primary id */
	tcell = afspag_GetPrimaryCell();
    }
    if (!tcell) return ESRCH;
    if (set_parent_pag) {
#if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
#if defined(AFS_DARWIN_ENV)
	struct proc *p = current_proc();	/* XXX */
#else
	struct proc *p = curproc;	/* XXX */
#endif
#ifndef AFS_DARWIN80_ENV
	uprintf("Process %d (%s) tried to change pags in PSetTokens\n",
		p->p_pid, p->p_comm);
#endif
	setpag(p, acred, -1, &pag, 1);
#else
#ifdef	AFS_OSF_ENV
	setpag(u.u_procp, acred, -1, &pag, 1);	/* XXX u.u_procp is a no-op XXX */
#else
	setpag(acred, -1, &pag, 1);
#endif
#endif
    }
    pag = PagInCred(*acred);
    uid = (pag == NOPAG) ? (*acred)->cr_uid : pag;
    /* now we just set the tokens */
    tu = afs_GetUser(uid, tcell->cellnum, WRITE_LOCK);
    if (!tu->cellinfo)
	tu->cellinfo = (void *)tcell;
    tu->vid = clear.ViceId;
    if (tu->stp != NULL) {
	afs_osi_Free(tu->stp, tu->stLen);
    }
    tu->stp = (char *)afs_osi_Alloc(stLen);
    tu->stLen = stLen;
    memcpy(tu->stp, stp, stLen);
    tu->ct = clear;
#ifndef AFS_NOSTATS
    afs_stats_cmfullperf.authent.TicketUpdates++;
    afs_ComputePAGStats();
#endif /* AFS_NOSTATS */
    tu->states |= UHasTokens;
    tu->states &= ~UTokensBad;
    afs_SetPrimary(tu, flag);
    tu->tokenTime = osi_Time();
    afs_PutUser(tu, WRITE_LOCK);

    return 0;
}

/*------------------------------------------------------------------------
 * EXPORTED afs_Analyze
 *
 * Description:
 *	Analyze the outcome of an RPC operation, taking whatever support
 *	actions are necessary.
 *
 * Arguments:
 *	aconn : Ptr to the relevant connection on which the call was made.
 *	acode : The return code experienced by the RPC.
 *	afid  : The FID of the file involved in the action.  This argument
 *		may be null if none was involved.
 *	areq  : The request record associated with this operation.
 *      op    : which RPC we are analyzing.
 *      cellp : pointer to a cell struct.  Must provide either fid or cell.
 *
 * Returns:
 *	Non-zero value if the related RPC operation should be retried,
 *	zero otherwise.
 *
 * Environment:
 *	This routine is typically called in a do-while loop, causing the
 *	embedded RPC operation to be called repeatedly if appropriate
 *	until whatever error condition (if any) is intolerable.
 *
 * Side Effects:
 *	As advertised.
 *
 * NOTE:
 *	The retry return value is used by afs_StoreAllSegments to determine
 *	if this is a temporary or permanent error.
 *------------------------------------------------------------------------*/
int
afs_Analyze(register struct afs_conn *aconn, afs_int32 acode,
	    struct VenusFid *afid, register struct vrequest *areq, int op,
	    afs_int32 locktype, struct cell *cellp)
{
    afs_int32 i;
    struct srvAddr *sa;
    struct server *tsp;
    struct volume *tvp;
    afs_int32 shouldRetry = 0;
    afs_int32 serversleft = 1;
    struct afs_stats_RPCErrors *aerrP;
    afs_int32 markeddown;

 
 
    if (AFS_IS_DISCONNECTED && !AFS_IN_SYNC) {
	/* On reconnection, act as connected. XXX: for now.... */
        /* SXW - This may get very tired after a while. We should try and
	 *       intercept all RPCs before they get here ... */
	/*printf("afs_Analyze: disconnected\n");*/
	afs_FinalizeReq(areq);
	if (aconn) {
	    /* SXW - I suspect that this will _never_ happen - we shouldn't
	     *       get a connection because we're disconnected !!!*/
	    afs_PutConn(aconn, locktype);
	}
	return 0;
    }
    
    AFS_STATCNT(afs_Analyze);
    afs_Trace4(afs_iclSetp, CM_TRACE_ANALYZE, ICL_TYPE_INT32, op,
	       ICL_TYPE_POINTER, aconn, ICL_TYPE_INT32, acode, ICL_TYPE_LONG,
	       areq->uid);

    aerrP = (struct afs_stats_RPCErrors *)0;

    if ((op >= 0) && (op < AFS_STATS_NUM_FS_RPC_OPS))
	aerrP = &(afs_stats_cmfullperf.rpc.fsRPCErrors[op]);

    afs_FinalizeReq(areq);
    if (!aconn && areq->busyCount) {	/* one RPC or more got VBUSY/VRESTARTING */

	tvp = afs_FindVolume(afid, READ_LOCK);
	if (tvp) {
	    afs_warnuser("afs: Waiting for busy volume %u (%s) in cell %s\n",
			 (afid ? afid->Fid.Volume : 0),
			 (tvp->name ? tvp->name : ""),
			 ((tvp->serverHost[0]
			   && tvp->serverHost[0]->cell) ? tvp->serverHost[0]->
			  cell->cellName : ""));

	    for (i = 0; i < MAXHOSTS; i++) {
		if (tvp->status[i] != not_busy && tvp->status[i] != offline) {
		    tvp->status[i] = not_busy;
		}
		if (tvp->status[i] == not_busy)
		    shouldRetry = 1;
	    }
	    afs_PutVolume(tvp, READ_LOCK);
	} else {
	    afs_warnuser("afs: Waiting for busy volume %u\n",
			 (afid ? afid->Fid.Volume : 0));
	}

	if (areq->busyCount > 100) {
	    if (aerrP)
		(aerrP->err_Volume)++;
//.........这里部分代码省略.........

static int
VLDB_Same(struct VenusFid *afid, struct vrequest *areq)
{
    struct vrequest treq;
    struct afs_conn *tconn;
    int i, type = 0;
    union {
	struct vldbentry tve;
	struct nvldbentry ntve;
	struct uvldbentry utve;
    } *v;
    struct volume *tvp;
    struct cell *tcell;
    char *bp, tbuf[CVBS];	/* biggest volume id is 2^32, ~ 4*10^9 */
    unsigned int changed;
    struct server *(oldhosts[NMAXNSERVERS]);

    AFS_STATCNT(CheckVLDB);
    afs_FinalizeReq(areq);

    if ((i = afs_InitReq(&treq, afs_osi_credp)))
	return DUNNO;
    v = afs_osi_Alloc(sizeof(*v));
    tcell = afs_GetCell(afid->Cell, READ_LOCK);
    bp = afs_cv2string(&tbuf[CVBS], afid->Fid.Volume);
    do {
	VSleep(2);		/* Better safe than sorry. */
	tconn =
	    afs_ConnByMHosts(tcell->cellHosts, tcell->vlport, tcell->cellNum,
			     &treq, SHARED_LOCK);
	if (tconn) {
	    if (tconn->srvr->server->flags & SNO_LHOSTS) {
		type = 0;
		RX_AFS_GUNLOCK();
		i = VL_GetEntryByNameO(tconn->id, bp, &v->tve);
		RX_AFS_GLOCK();
	    } else if (tconn->srvr->server->flags & SYES_LHOSTS) {
		type = 1;
		RX_AFS_GUNLOCK();
		i = VL_GetEntryByNameN(tconn->id, bp, &v->ntve);
		RX_AFS_GLOCK();
	    } else {
		type = 2;
		RX_AFS_GUNLOCK();
		i = VL_GetEntryByNameU(tconn->id, bp, &v->utve);
		RX_AFS_GLOCK();
		if (!(tconn->srvr->server->flags & SVLSRV_UUID)) {
		    if (i == RXGEN_OPCODE) {
			type = 1;
			RX_AFS_GUNLOCK();
			i = VL_GetEntryByNameN(tconn->id, bp, &v->ntve);
			RX_AFS_GLOCK();
			if (i == RXGEN_OPCODE) {
			    type = 0;
			    tconn->srvr->server->flags |= SNO_LHOSTS;
			    RX_AFS_GUNLOCK();
			    i = VL_GetEntryByNameO(tconn->id, bp, &v->tve);
			    RX_AFS_GLOCK();
			} else if (!i)
			    tconn->srvr->server->flags |= SYES_LHOSTS;
		    } else if (!i)
			tconn->srvr->server->flags |= SVLSRV_UUID;
		}
		lastcode = i;
	    }
	} else
	    i = -1;
    } while (afs_Analyze(tconn, i, NULL, &treq, -1,	/* no op code for this */
			 SHARED_LOCK, tcell));

    afs_PutCell(tcell, READ_LOCK);
    afs_Trace2(afs_iclSetp, CM_TRACE_CHECKVLDB, ICL_TYPE_FID, &afid,
	       ICL_TYPE_INT32, i);

    if (i) {
	afs_osi_Free(v, sizeof(*v));
	return DUNNO;
    }
    /* have info, copy into serverHost array */
    changed = 0;
    tvp = afs_FindVolume(afid, WRITE_LOCK);
    if (tvp) {
	ObtainWriteLock(&tvp->lock, 107);
	for (i = 0; i < NMAXNSERVERS && tvp->serverHost[i]; i++) {
	    oldhosts[i] = tvp->serverHost[i];
	}

	if (type == 2) {
	    InstallUVolumeEntry(tvp, &v->utve, afid->Cell, tcell, &treq);
	} else if (type == 1) {
	    InstallNVolumeEntry(tvp, &v->ntve, afid->Cell);
	} else {
	    InstallVolumeEntry(tvp, &v->tve, afid->Cell);
	}

	if (i < NMAXNSERVERS && tvp->serverHost[i]) {
	    changed = 1;
	}
	for (--i; !changed && i >= 0; i--) {
	    if (tvp->serverHost[i] != oldhosts[i]) {
//.........这里部分代码省略.........

/* lp is pointer to a fairly-old buffer */
static struct buffer *
afs_newslot(struct dcache *adc, afs_int32 apage, struct buffer *lp)
{
    /* Find a usable buffer slot */
    afs_int32 i;
    afs_int32 lt = 0;
    struct buffer *tp;
    struct osi_file *tfile;

    AFS_STATCNT(afs_newslot);
    /* we take a pointer here to a buffer which was at the end of an
     * LRU hash chain.  Odds are, it's one of the older buffers, not
     * one of the newer.  Having an older buffer to start with may
     * permit us to avoid a few of the assignments in the "typical
     * case" for loop below.
     */
    if (lp && (lp->lockers == 0)) {
	lt = lp->accesstime;
    } else {
	lp = NULL;
    }

    /* timecounter might have wrapped, if machine is very very busy
     * and stays up for a long time.  Timecounter mustn't wrap twice
     * (positive->negative->positive) before calling newslot, but that
     * would require 2 billion consecutive cache hits... Anyway, the
     * penalty is only that the cache replacement policy will be
     * almost MRU for the next ~2 billion DReads...  newslot doesn't
     * get called nearly as often as DRead, so in order to avoid the
     * performance penalty of using the hypers, it's worth doing the
     * extra check here every time.  It's probably cheaper than doing
     * hcmp, anyway.  There is a little performance hit resulting from
     * resetting all the access times to 0, but it only happens once
     * every month or so, and the access times will rapidly sort
     * themselves back out after just a few more DReads.
     */
    if (timecounter < 0) {
	timecounter = 1;
	tp = Buffers;
	for (i = 0; i < nbuffers; i++, tp++) {
	    tp->accesstime = 0;
	    if (!lp && !tp->lockers)	/* one is as good as the rest, I guess */
		lp = tp;
	}
    } else {
	/* this is the typical case */
	tp = Buffers;
	for (i = 0; i < nbuffers; i++, tp++) {
	    if (tp->lockers == 0) {
		if (!lp || tp->accesstime < lt) {
		    lp = tp;
		    lt = tp->accesstime;
		}
	    }
	}
    }

    if (lp == 0) {
	/* No unlocked buffers. If still possible, allocate a new increment */
	if (nbuffers + NPB > afs_max_buffers) {
	    /* There are no unlocked buffers -- this used to panic, but that
	     * seems extreme.  To the best of my knowledge, all the callers
	     * of DRead are prepared to handle a zero return.  Some of them
	     * just panic directly, but not all of them. */
	    afs_warn("afs: all buffers locked\n");
	    return 0;
	}

	BufferData = afs_osi_Alloc(AFS_BUFFER_PAGESIZE * NPB);
	osi_Assert(BufferData != NULL);
	for (i = 0; i< NPB; i++) {
	    /* Fill in each buffer with an empty indication. */
	    tp = &Buffers[i + nbuffers];
	    tp->fid = NULLIDX;
	    afs_reset_inode(&tp->inode);
	    tp->accesstime = 0;
	    tp->lockers = 0;
	    tp->data = &BufferData[AFS_BUFFER_PAGESIZE * i];
	    tp->hashIndex = 0;
	    tp->dirty = 0;
	    AFS_RWLOCK_INIT(&tp->lock, "buffer lock");
	}
	lp = &Buffers[nbuffers];
	nbuffers += NPB;
    }

    if (lp->dirty) {
	/* see DFlush for rationale for not getting and locking the dcache */
        tfile = afs_CFileOpen(&lp->inode);
	afs_CFileWrite(tfile, lp->page * AFS_BUFFER_PAGESIZE, lp->data,
		       AFS_BUFFER_PAGESIZE);
	lp->dirty = 0;
	afs_CFileClose(tfile);
	AFS_STATS(afs_stats_cmperf.bufFlushDirty++);
    }

    /* Now fill in the header. */
    lp->fid = adc->index;
    afs_copy_inode(&lp->inode, &adc->f.inode);
//.........这里部分代码省略.........

int
afs_mountroot(void)
{
    AFS_STATCNT(afs_mountroot);
    return (EINVAL);
}

afs_fid(OSI_VC_DECL(avc), struct fid **fidpp)
#endif				/* AFS_AIX41_ENV */
{
    struct SmallFid Sfid;
    long addr[2];
    register struct cell *tcell;
    extern struct vcache *afs_globalVp;
    int SizeOfSmallFid = SIZEOF_SMALLFID;
    int rootvp = 0;
    OSI_VC_CONVERT(avc);

    AFS_STATCNT(afs_fid);

    if (afs_shuttingdown)
	return EIO;

    if (afs_NFSRootOnly && (avc == afs_globalVp))
	rootvp = 1;
    if (!afs_NFSRootOnly || rootvp
#ifdef AFS_AIX41_ENV
	|| USE_SMALLFID(credp)
#endif
	) {
	tcell = afs_GetCell(avc->f.fid.Cell, READ_LOCK);
	Sfid.Volume = avc->f.fid.Fid.Volume;
	Sfid.Vnode = avc->f.fid.Fid.Vnode;
	Sfid.CellAndUnique =
	    ((tcell->cellIndex << 24) + (avc->f.fid.Fid.Unique & 0xffffff));
	afs_PutCell(tcell, READ_LOCK);
	if (avc->f.fid.Fid.Vnode > 0xffff)
	    afs_fid_vnodeoverflow++;
	if (avc->f.fid.Fid.Unique > 0xffffff)
	    afs_fid_uniqueoverflow++;
    } else {
#if defined(AFS_SUN57_64BIT_ENV) || (defined(AFS_SGI61_ENV) && (_MIPS_SZPTR == 64))
	addr[1] = (long)AFS_XLATOR_MAGIC << 48;
#else /* defined(AFS_SGI61_ENV) && (_MIPS_SZPTR == 64) */
	addr[1] = AFS_XLATOR_MAGIC;
	SizeOfSmallFid = sizeof(addr);
#endif /* defined(AFS_SGI61_ENV) && (_MIPS_SZPTR == 64) */
	addr[0] = (long)avc;
#ifndef AFS_AIX41_ENV
	/* No post processing, so don't hold ref count. */
	AFS_FAST_HOLD(avc);
#endif
    }
#if	defined(AFS_AIX_ENV) || defined(AFS_SUN54_ENV)
    /* Use the fid pointer passed to us. */
    fidpp->fid_len = SizeOfSmallFid;

    if (afs_NFSRootOnly) {
	if (rootvp
#ifdef AFS_AIX41_ENV
	    || USE_SMALLFID(credp)
#endif
	    ) {
	    memcpy(fidpp->fid_data, (caddr_t) & Sfid, SizeOfSmallFid);
	} else {
	    memcpy(fidpp->fid_data, (caddr_t) addr, SizeOfSmallFid);
	}
    } else {
	memcpy(fidpp->fid_data, (caddr_t) & Sfid, SizeOfSmallFid);
    }
#else
    /* malloc a fid pointer ourselves. */
    *fidpp = (struct fid *)AFS_KALLOC(SizeOfSmallFid + 2);
    (*fidpp)->fid_len = SizeOfSmallFid;
    if (afs_NFSRootOnly) {
	if (rootvp) {
	    memcpy((*fidpp)->fid_data, (char *)&Sfid, SizeOfSmallFid);
	} else {
	    memcpy((*fidpp)->fid_data, (char *)addr, SizeOfSmallFid);
	}
    } else {
	memcpy((*fidpp)->fid_data, (char *)&Sfid, SizeOfSmallFid);
    }
#endif
    return (0);
}

int
afs_swapvp(void)
{
    AFS_STATCNT(afs_swapvp);
    return (EINVAL);
}

/*!
 * Create or update a cell entry.
 * \param acellName Name of cell.
 * \param acellHosts Array of hosts that this cell has.
 * \param aflags Cell flags.
 * \param linkedcname
 * \param fsport File server port.
 * \param vlport Volume server port.
 * \param timeout Cell timeout value, 0 means static AFSDB entry.
 * \return
 */
afs_int32
afs_NewCell(char *acellName, afs_int32 * acellHosts, int aflags,
	    char *linkedcname, u_short fsport, u_short vlport, int timeout)
{
    struct cell *tc, *tcl = 0;
    afs_int32 i, newc = 0, code = 0;

    AFS_STATCNT(afs_NewCell);

    ObtainWriteLock(&afs_xcell, 103);

    tc = afs_FindCellByName_nl(acellName, READ_LOCK);
    if (tc) {
	aflags &= ~CNoSUID;
    } else {
	tc = afs_osi_Alloc(sizeof(struct cell));
	osi_Assert(tc != NULL);
	memset(tc, 0, sizeof(*tc));
	tc->cellName = afs_strdup(acellName);
	tc->fsport = AFS_FSPORT;
	tc->vlport = AFS_VLPORT;
	AFS_MD5_String(tc->cellHandle, tc->cellName, strlen(tc->cellName));
	AFS_RWLOCK_INIT(&tc->lock, "cell lock");
	newc = 1;
	aflags |= CNoSUID;
    }
    ObtainWriteLock(&tc->lock, 688);

    /* If the cell we've found has the correct name but no timeout,
     * and we're called with a non-zero timeout, bail out:  never
     * override static configuration entries with AFSDB ones.
     * One exception: if the original cell entry had no servers,
     * it must get servers from AFSDB.
     */
    if (timeout && !tc->timeout && tc->cellHosts[0]) {
	code = EEXIST;		/* This code is checked for in afs_LookupAFSDB */
	goto bad;
    }

    /* we don't want to keep pinging old vlservers which were down,
     * since they don't matter any more.  It's easier to do this than
     * to remove the server from its various hash tables. */
    for (i = 0; i < AFS_MAXCELLHOSTS; i++) {
	if (!tc->cellHosts[i])
	    break;
	tc->cellHosts[i]->flags &= ~SRVR_ISDOWN;
	tc->cellHosts[i]->flags |= SRVR_ISGONE;
    }

    if (fsport)
	tc->fsport = fsport;
    if (vlport)
	tc->vlport = vlport;

    if (aflags & CLinkedCell) {
	if (!linkedcname) {
	    code = EINVAL;
	    goto bad;
	}
	tcl = afs_FindCellByName_nl(linkedcname, READ_LOCK);
	if (!tcl) {
	    code = ENOENT;
	    goto bad;
	}
	if (tcl->lcellp) {	/* XXX Overwriting if one existed before! XXX */
	    tcl->lcellp->lcellp = (struct cell *)0;
	    tcl->lcellp->states &= ~CLinkedCell;
	}
	tc->lcellp = tcl;
	tcl->lcellp = tc;
    }
    tc->states |= aflags;
    tc->timeout = timeout;

    memset(tc->cellHosts, 0, sizeof(tc->cellHosts));
    for (i = 0; i < AFS_MAXCELLHOSTS; i++) {
	/* Get server for each host and link this cell in.*/
	struct server *ts;
	afs_uint32 temp = acellHosts[i];
	if (!temp)
	    break;
	ts = afs_GetServer(&temp, 1, 0, tc->vlport, WRITE_LOCK, NULL, 0);
	ts->cell = tc;
	ts->flags &= ~SRVR_ISGONE;
	/* Set the server as a host of the new cell. */
	tc->cellHosts[i] = ts;
	afs_PutServer(ts, WRITE_LOCK);
    }
    afs_SortServers(tc->cellHosts, AFS_MAXCELLHOSTS);	/* randomize servers */
//.........这里部分代码省略.........

afs_root(struct mount *mp, struct vnode **vpp)
#endif
{
    int error;
    struct vrequest treq;
    register struct vcache *tvp = 0;
#ifdef AFS_FBSD50_ENV
#ifndef AFS_FBSD53_ENV
    struct thread *td = curthread;
#endif
    struct ucred *cr = td->td_ucred;
#else
    struct proc *p = curproc;
    struct ucred *cr = p->p_cred->pc_ucred;
#endif

    AFS_GLOCK();
    AFS_STATCNT(afs_root);
    crhold(cr);
    if (afs_globalVp && (afs_globalVp->f.states & CStatd)) {
	tvp = afs_globalVp;
	error = 0;
    } else {
tryagain:
#ifndef AFS_FBSD80_ENV
	if (afs_globalVp) {
	    afs_PutVCache(afs_globalVp);
	    /* vrele() needed here or not? */
	    afs_globalVp = NULL;
	}
#endif
	if (!(error = afs_InitReq(&treq, cr)) && !(error = afs_CheckInit())) {
	    tvp = afs_GetVCache(&afs_rootFid, &treq, NULL, NULL);
	    /* we really want this to stay around */
	    if (tvp)
		afs_globalVp = tvp;
	    else
		error = ENOENT;
	}
    }
    if (tvp) {
	struct vnode *vp = AFSTOV(tvp);

#ifdef AFS_FBSD50_ENV
	ASSERT_VI_UNLOCKED(vp, "afs_root");
#endif
	AFS_GUNLOCK();
	/*
	 * I'm uncomfortable about this.  Shouldn't this happen at a
	 * higher level, and shouldn't we busy the top-level directory
	 * to prevent recycling?
	 */
#ifdef AFS_FBSD50_ENV
	error = vget(vp, LK_EXCLUSIVE | LK_RETRY, td);
	vp->v_vflag |= VV_ROOT;
#else
	error = vget(vp, LK_EXCLUSIVE | LK_RETRY, p);
	vp->v_flag |= VROOT;
#endif
	AFS_GLOCK();
	if (error != 0)
		goto tryagain;

	afs_globalVFS = mp;
	*vpp = vp;
    }

    afs_Trace2(afs_iclSetp, CM_TRACE_VFSROOT, ICL_TYPE_POINTER, tvp ? AFSTOV(tvp) : NULL,
	       ICL_TYPE_INT32, error);
    AFS_GUNLOCK();
    crfree(cr);
    return error;
}

int
afs_MemRead(struct vcache *avc, struct uio *auio,
	    afs_ucred_t *acred, daddr_t albn, struct buf **abpp,
	    int noLock)
{
    afs_size_t totalLength;
    afs_size_t transferLength;
    afs_size_t filePos;
    afs_size_t offset, tlen;
    afs_size_t len = 0;
    afs_int32 trimlen;
    struct dcache *tdc = 0;
    afs_int32 error, trybusy = 1;
    afs_int32 code;
    struct vrequest *treq = NULL;
#ifdef AFS_DARWIN80_ENV
    uio_t tuiop = NULL;
#else
    struct uio tuio;
    struct uio *tuiop = &tuio;
    struct iovec *tvec;
    memset(&tuio, 0, sizeof(tuio));
#endif

    AFS_STATCNT(afs_MemRead);
    if (avc->vc_error)
	return EIO;

    /* check that we have the latest status info in the vnode cache */
    if ((code = afs_CreateReq(&treq, acred)))
	return code;
    if (!noLock) {
	code = afs_VerifyVCache(avc, treq);
	if (code) {
	    code = afs_CheckCode(code, treq, 8);	/* failed to get it */
	    afs_DestroyReq(treq);
	    return code;
	}
    }
#ifndef	AFS_VM_RDWR_ENV
    if (AFS_NFSXLATORREQ(acred)) {
	if (!afs_AccessOK
	    (avc, PRSFS_READ, treq,
	     CHECK_MODE_BITS | CMB_ALLOW_EXEC_AS_READ)) {
	    code = afs_CheckCode(EACCES, treq, 9);
	    afs_DestroyReq(treq);
	    return code;
	}
    }
#endif

#ifndef AFS_DARWIN80_ENV
    tvec = (struct iovec *)osi_AllocSmallSpace(sizeof(struct iovec));
    memset(tvec, 0, sizeof(struct iovec));
#endif
    totalLength = AFS_UIO_RESID(auio);
    filePos = AFS_UIO_OFFSET(auio);
    afs_Trace4(afs_iclSetp, CM_TRACE_READ, ICL_TYPE_POINTER, avc,
	       ICL_TYPE_OFFSET, ICL_HANDLE_OFFSET(filePos), ICL_TYPE_INT32,
	       totalLength, ICL_TYPE_OFFSET,
	       ICL_HANDLE_OFFSET(avc->f.m.Length));
    error = 0;
    transferLength = 0;
    if (!noLock)
	ObtainReadLock(&avc->lock);
#if	defined(AFS_TEXT_ENV) && !defined(AFS_VM_RDWR_ENV)
    if (avc->flushDV.high == AFS_MAXDV && avc->flushDV.low == AFS_MAXDV) {
	hset(avc->flushDV, avc->f.m.DataVersion);
    }
#endif

    /*
     * Locks held:
     * avc->lock(R)
     */

    /* This bit is bogus. We're checking to see if the read goes past the
     * end of the file. If so, we should be zeroing out all of the buffers
     * that the client has passed into us (there is a danger that we may leak
     * kernel memory if we do not). However, this behaviour is disabled by
     * not setting len before this segment runs, and by setting len to 0
     * immediately we enter it. In addition, we also need to check for a read
     * which partially goes off the end of the file in the while loop below.
     */

    if (filePos >= avc->f.m.Length) {
	if (len > AFS_ZEROS)
	    len = sizeof(afs_zeros);	/* and in 0 buffer */
	len = 0;
#ifdef AFS_DARWIN80_ENV
	trimlen = len;
	tuiop = afsio_darwin_partialcopy(auio, trimlen);
#else
	afsio_copy(auio, &tuio, tvec);
	trimlen = len;
	afsio_trim(&tuio, trimlen);
#endif
	AFS_UIOMOVE(afs_zeros, trimlen, UIO_READ, tuiop, code);
    }

//.........这里部分代码省略.........

/* question: does afs_create need to set CDirty in the adp or the avc?
 * I think we can get away without it, but I'm not sure.  Note that
 * afs_setattr is called in here for truncation.
 */
#ifdef AFS_SGI64_ENV
int
afs_create(OSI_VC_DECL(adp), char *aname, struct vattr *attrs, int flags,
	   int amode, struct vcache **avcp, afs_ucred_t *acred)
#else /* AFS_SGI64_ENV */
int
afs_create(OSI_VC_DECL(adp), char *aname, struct vattr *attrs,
	   enum vcexcl aexcl, int amode, struct vcache **avcp,
	   afs_ucred_t *acred)
#endif				/* AFS_SGI64_ENV */
{
    afs_int32 origCBs, origZaps, finalZaps;
    struct vrequest *treq = NULL;
    afs_int32 code;
    struct afs_conn *tc;
    struct VenusFid newFid;
    struct AFSStoreStatus InStatus;
    struct AFSFetchStatus *OutFidStatus, *OutDirStatus;
    struct AFSVolSync tsync;
    struct AFSCallBack CallBack;
    afs_int32 now;
    struct dcache *tdc;
    afs_size_t offset, len;
    struct server *hostp = 0;
    struct vcache *tvc;
    struct volume *volp = 0;
    struct afs_fakestat_state fakestate;
    struct rx_connection *rxconn;
    XSTATS_DECLS;
    OSI_VC_CONVERT(adp);

    AFS_STATCNT(afs_create);

    OutFidStatus = osi_AllocSmallSpace(sizeof(struct AFSFetchStatus));
    OutDirStatus = osi_AllocSmallSpace(sizeof(struct AFSFetchStatus));
    memset(&InStatus, 0, sizeof(InStatus));

    if ((code = afs_CreateReq(&treq, acred)))
	goto done2;

    afs_Trace3(afs_iclSetp, CM_TRACE_CREATE, ICL_TYPE_POINTER, adp,
	       ICL_TYPE_STRING, aname, ICL_TYPE_INT32, amode);

    afs_InitFakeStat(&fakestate);

#ifdef AFS_SGI65_ENV
    /* If avcp is passed not null, it's the old reference to this file.
     * We can use this to avoid create races. For now, just decrement
     * the reference count on it.
     */
    if (*avcp) {
	AFS_RELE(AFSTOV(*avcp));
	*avcp = NULL;
    }
#endif

    if (