2 * Copyright 2000, International Business Machines Corporation and others.
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
14 * afs_StoreOnLastReference
19 #include <afsconfig.h>
20 #include "afs/param.h"
23 #include "afs/sysincludes.h" /* Standard vendor system headers */
24 #include "afsincludes.h" /* Afs-based standard headers */
25 #include "afs/afs_stats.h" /* statistics */
26 #include "afs/afs_cbqueue.h"
27 #include "afs/nfsclient.h"
28 #include "afs/afs_osidnlc.h"
31 extern unsigned char *afs_indexFlags;
33 /* Called by all write-on-close routines: regular afs_close,
34 * store via background daemon and store via the
35 * afs_FlushActiveVCaches routine (when CCORE is on).
36 * avc->lock must be write-locked.
39 afs_StoreOnLastReference(struct vcache *avc,
40 struct vrequest *treq)
44 AFS_STATCNT(afs_StoreOnLastReference);
45 /* if CCore flag is set, we clear it and do the extra decrement
46 * ourselves now. If we're called by the CCore clearer, the CCore
47 * flag will already be clear, so we don't have to worry about
48 * clearing it twice. */
49 if (avc->f.states & CCore) {
52 avc->f.states &= ~CCore;
53 #if defined(AFS_SGI_ENV)
54 osi_Assert(avc->opens > 0 && avc->execsOrWriters > 0);
56 /* WARNING: Our linux cm code treats the execsOrWriters counter differently
57 * depending on the flags the file was opened with. So, if you make any
58 * changes to the way the execsOrWriters flag is handled check with the
61 avc->execsOrWriters--;
62 AFS_RELE(AFSTOV(avc)); /* VN_HOLD at set CCore(afs_FakeClose) */
63 cred = (afs_ucred_t *)avc->linkData; /* "crheld" in afs_FakeClose */
68 if (!AFS_IS_DISCONNECTED) {
71 /* Now, send the file back. Used to require 0 writers left, but now do
72 * it on every close for write, since two closes in a row are harmless
73 * since first will clean all chunks, and second will be noop. Note that
74 * this will also save confusion when someone keeps a file open
75 * inadvertently, since with old system, writes to the server would never
78 code = afs_StoreAllSegments(avc, treq, AFS_LASTSTORE /*!sync-to-disk */ );
80 * We have to do these after the above store in done: in some systems
81 * like aix they'll need to flush all the vm dirty pages to the disk via
82 * the strategy routine. During that all procedure (done under no avc
83 * locks) opens, refcounts would be zero, since it didn't reach the
84 * afs_{rd,wr} routines which means the vcache is a perfect candidate
87 } else if (AFS_IS_DISCON_RW) {
88 afs_DisconAddDirty(avc, VDisconWriteClose, 0);
89 } /* if not disconnected */
91 #if defined(AFS_SGI_ENV)
92 osi_Assert(avc->opens > 0 && avc->execsOrWriters > 0);
96 avc->execsOrWriters--;
101 afs_UFSWriteUIO(struct vcache *avc, afs_dcache_id_t *inode, struct uio *tuiop)
103 struct osi_file *tfile;
106 tfile = (struct osi_file *)osi_UFSOpen(inode);
110 #if defined(AFS_AIX41_ENV)
112 code = VNOP_RDWR(tfile->vnode, UIO_WRITE, FWRITE, tuiop, NULL, NULL,
113 NULL, afs_osi_credp);
115 #elif defined(AFS_AIX32_ENV)
116 code = VNOP_RDWR(tfile->vnode, UIO_WRITE, FWRITE, tuiop, NULL, NULL);
117 #elif defined(AFS_AIX_ENV)
118 code = VNOP_RDWR(tfile->vnode, UIO_WRITE, FWRITE, (off_t) &offset,
119 tuiop, NULL, NULL, -1);
120 #elif defined(AFS_SUN5_ENV)
122 # ifdef AFS_SUN510_ENV
123 VOP_RWLOCK(tfile->vnode, 1, NULL);
124 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp, NULL);
125 VOP_RWUNLOCK(tfile->vnode, 1, NULL);
127 VOP_RWLOCK(tfile->vnode, 1);
128 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp);
129 VOP_RWUNLOCK(tfile->vnode, 1);
134 ("\n\n\n*** Cache partition is full - decrease cachesize!!! ***\n\n\n");
135 #elif defined(AFS_SGI_ENV)
137 avc->f.states |= CWritingUFS;
138 AFS_VOP_RWLOCK(tfile->vnode, VRWLOCK_WRITE);
139 AFS_VOP_WRITE(tfile->vnode, tuiop, IO_ISLOCKED, afs_osi_credp, code);
140 AFS_VOP_RWUNLOCK(tfile->vnode, VRWLOCK_WRITE);
141 avc->f.states &= ~CWritingUFS;
143 #elif defined(AFS_HPUX100_ENV)
146 code = VOP_RDWR(tfile->vnode, tuiop, UIO_WRITE, 0, afs_osi_credp);
149 #elif defined(AFS_LINUX20_ENV)
151 code = osi_rdwr(tfile, tuiop, UIO_WRITE);
153 #elif defined(AFS_DARWIN80_ENV)
155 code = VNOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_ctxtp);
157 #elif defined(AFS_DARWIN_ENV)
159 VOP_LOCK(tfile->vnode, LK_EXCLUSIVE, current_proc());
160 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp);
161 VOP_UNLOCK(tfile->vnode, 0, current_proc());
163 #elif defined(AFS_FBSD80_ENV)
165 VOP_LOCK(tfile->vnode, LK_EXCLUSIVE);
166 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp);
167 VOP_UNLOCK(tfile->vnode, 0);
169 #elif defined(AFS_FBSD_ENV)
171 VOP_LOCK(tfile->vnode, LK_EXCLUSIVE, curthread);
172 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp);
173 VOP_UNLOCK(tfile->vnode, 0, curthread);
175 #elif defined(AFS_NBSD_ENV)
177 VOP_LOCK(tfile->vnode, LK_EXCLUSIVE);
178 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp);
179 #if defined(AFS_NBSD60_ENV)
180 VOP_UNLOCK(tfile->vnode);
182 VOP_UNLOCK(tfile->vnode, 0);
185 #elif defined(AFS_XBSD_ENV)
187 VOP_LOCK(tfile->vnode, LK_EXCLUSIVE, curproc);
188 code = VOP_WRITE(tfile->vnode, tuiop, 0, afs_osi_credp);
189 VOP_UNLOCK(tfile->vnode, 0, curproc);
193 tuio.uio_fpflags &= ~FSYNCIO; /* don't do sync io */
195 code = VOP_RDWR(tfile->vnode, tuiop, UIO_WRITE, 0, afs_osi_credp);
202 /* called on writes */
204 afs_write(struct vcache *avc, struct uio *auio, int aio,
205 afs_ucred_t *acred, int noLock)
207 afs_size_t totalLength;
208 afs_size_t transferLength;
210 afs_size_t offset, len;
220 #if defined(AFS_FBSD_ENV) || defined(AFS_DFBSD_ENV)
221 struct vnode *vp = AFSTOV(avc);
223 struct uio *tuiop = NULL;
225 struct vrequest *treq = NULL;
227 AFS_STATCNT(afs_write);
230 return avc->vc_error;
232 if (AFS_IS_DISCONNECTED && !AFS_IS_DISCON_RW)
235 startDate = osi_Time();
236 if ((code = afs_CreateReq(&treq, acred)))
238 /* otherwise we read */
239 totalLength = AFS_UIO_RESID(auio);
240 filePos = AFS_UIO_OFFSET(auio);
243 afs_Trace4(afs_iclSetp, CM_TRACE_WRITE, ICL_TYPE_POINTER, avc,
244 ICL_TYPE_OFFSET, ICL_HANDLE_OFFSET(filePos), ICL_TYPE_OFFSET,
245 ICL_HANDLE_OFFSET(totalLength), ICL_TYPE_OFFSET,
246 ICL_HANDLE_OFFSET(avc->f.m.Length));
248 afs_MaybeWakeupTruncateDaemon();
249 ObtainWriteLock(&avc->lock, 556);
251 #if defined(AFS_SGI_ENV)
255 * afs_xwrite handles setting m.Length
256 * and handles APPEND mode.
257 * Since we are called via strategy, we need to trim the write to
258 * the actual size of the file
260 osi_Assert(filePos <= avc->f.m.Length);
261 diff = avc->f.m.Length - filePos;
262 AFS_UIO_SETRESID(auio, MIN(totalLength, diff));
263 totalLength = AFS_UIO_RESID(auio);
266 if (aio & IO_APPEND) {
267 /* append mode, start it at the right spot */
268 #if defined(AFS_SUN5_ENV)
269 auio->uio_loffset = 0;
271 filePos = avc->f.m.Length;
272 AFS_UIO_SETOFFSET(auio, avc->f.m.Length);
276 * Note that we use startDate rather than calling osi_Time() here.
277 * This is to avoid counting lock-waiting time in file date (for ranlib).
279 avc->f.m.Date = startDate;
281 #if defined(AFS_HPUX_ENV)
282 #if defined(AFS_HPUX101_ENV)
283 if ((totalLength + filePos) >> 9 >
284 p_rlimit(u.u_procp)[RLIMIT_FSIZE].rlim_cur) {
286 if ((totalLength + filePos) >> 9 > u.u_rlimit[RLIMIT_FSIZE].rlim_cur) {
289 ReleaseWriteLock(&avc->lock);
290 afs_DestroyReq(treq);
294 #if defined(AFS_VM_RDWR_ENV) && !defined(AFS_FAKEOPEN_ENV)
296 * If write is implemented via VM, afs_FakeOpen() is called from the
297 * high-level write op.
299 if (avc->execsOrWriters <= 0) {
300 afs_warn("WARNING: afs_ufswr vcp=%lx, exOrW=%d\n", (unsigned long)avc,
301 avc->execsOrWriters);
306 avc->f.states |= CDirty;
308 while (totalLength > 0) {
309 tdc = afs_ObtainDCacheForWriting(avc, filePos, totalLength, treq,
315 len = totalLength; /* write this amount by default */
316 offset = filePos - AFS_CHUNKTOBASE(tdc->f.chunk);
317 max = AFS_CHUNKTOSIZE(tdc->f.chunk); /* max size of this chunk */
318 if (max <= len + offset) { /*if we'd go past the end of this chunk */
319 /* it won't all fit in this chunk, so write as much
327 tuiop = afsio_partialcopy(auio, trimlen);
328 AFS_UIO_SETOFFSET(tuiop, offset);
330 code = (*(afs_cacheType->vwriteUIO))(avc, &tdc->f.inode, tuiop);
336 ZapDCE(tdc); /* bad data */
337 cfile = afs_CFileOpen(&tdc->f.inode);
339 afs_CFileTruncate(cfile, 0);
340 afs_CFileClose(cfile);
341 afs_AdjustSize(tdc, 0); /* sets f.chunkSize to 0 */
343 afs_stats_cmperf.cacheCurrDirtyChunks--;
344 afs_indexFlags[tdc->index] &= ~IFDataMod; /* so it does disappear */
345 ReleaseWriteLock(&tdc->lock);
349 /* otherwise we've written some, fixup length, etc and continue with next seg */
350 len = len - AFS_UIO_RESID(tuiop); /* compute amount really transferred */
352 afsio_skip(auio, tlen); /* advance auio over data written */
353 /* compute new file size */
354 if (offset + len > tdc->f.chunkBytes) {
355 afs_int32 tlength = offset + len;
356 afs_AdjustSize(tdc, tlength);
357 if (tdc->validPos < filePos + len)
358 tdc->validPos = filePos + len;
361 transferLength += len;
363 #if defined(AFS_SGI_ENV)
364 /* afs_xwrite handles setting m.Length */
365 osi_Assert(filePos <= avc->f.m.Length);
367 if (filePos > avc->f.m.Length) {
368 if (AFS_IS_DISCON_RW)
369 afs_PopulateDCache(avc, filePos, treq);
370 afs_Trace4(afs_iclSetp, CM_TRACE_SETLENGTH, ICL_TYPE_STRING,
371 __FILE__, ICL_TYPE_LONG, __LINE__, ICL_TYPE_OFFSET,
372 ICL_HANDLE_OFFSET(avc->f.m.Length), ICL_TYPE_OFFSET,
373 ICL_HANDLE_OFFSET(filePos));
374 avc->f.m.Length = filePos;
375 #if defined(AFS_FBSD_ENV) || defined(AFS_DFBSD_ENV)
376 vnode_pager_setsize(vp, filePos);
380 ReleaseWriteLock(&tdc->lock);
382 #if !defined(AFS_VM_RDWR_ENV)
384 * If write is implemented via VM, afs_DoPartialWrite() is called from
385 * the high-level write op.
388 code = afs_DoPartialWrite(avc, treq);
396 #if !defined(AFS_VM_RDWR_ENV) || defined(AFS_FAKEOPEN_ENV)
397 afs_FakeClose(avc, acred);
399 error = afs_CheckCode(error, treq, 7);
400 /* This set is here so we get the CheckCode. */
401 if (error && !avc->vc_error)
402 avc->vc_error = error;
404 ReleaseWriteLock(&avc->lock);
408 #ifndef AFS_VM_RDWR_ENV
410 * If write is implemented via VM, afs_fsync() is called from the high-level
413 #if defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
414 if (noLock && (aio & IO_SYNC)) {
417 /* On hpux on synchronous writes syncio will be set to IO_SYNC. If
418 * we're doing them because the file was opened with O_SYNCIO specified,
419 * we have to look in the u area. No single mechanism here!!
421 if (noLock && ((aio & IO_SYNC) | (auio->uio_fpflags & FSYNCIO))) {
423 if (noLock && (aio & FSYNC)) {
426 if (!AFS_NFSXLATORREQ(acred))
427 afs_fsync(avc, acred);
430 afs_DestroyReq(treq);
434 /* do partial write if we're low on unmodified chunks */
436 afs_DoPartialWrite(struct vcache *avc, struct vrequest *areq)
440 if (afs_stats_cmperf.cacheCurrDirtyChunks <=
441 afs_stats_cmperf.cacheMaxDirtyChunks
442 || AFS_IS_DISCONNECTED)
443 return 0; /* nothing to do */
444 /* otherwise, call afs_StoreDCache (later try to do this async, if possible) */
445 afs_Trace2(afs_iclSetp, CM_TRACE_PARTIALWRITE, ICL_TYPE_POINTER, avc,
446 ICL_TYPE_OFFSET, ICL_HANDLE_OFFSET(avc->f.m.Length));
448 #if defined(AFS_SUN5_ENV)
449 code = afs_StoreAllSegments(avc, areq, AFS_ASYNC | AFS_VMSYNC_INVAL);
451 code = afs_StoreAllSegments(avc, areq, AFS_ASYNC);
456 /* handle any closing cleanup stuff */
458 #if defined(AFS_SGI65_ENV)
459 afs_close(OSI_VC_DECL(avc), afs_int32 aflags, lastclose_t lastclose,
461 #elif defined(AFS_SGI64_ENV)
462 afs_close(OSI_VC_DECL(avc), afs_int32 aflags, lastclose_t lastclose,
463 off_t offset, afs_ucred_t *acred, struct flid *flp)
464 #elif defined(AFS_SGI_ENV)
465 afs_close(OSI_VC_DECL(avc), afs_int32 aflags, lastclose_t lastclose
466 off_t offset, afs_ucred_t *acred)
467 #elif defined(AFS_SUN5_ENV)
468 afs_close(OSI_VC_DECL(avc), afs_int32 aflags, int count, offset_t offset,
471 afs_close(OSI_VC_DECL(avc), afs_int32 aflags, afs_ucred_t *acred)
475 afs_int32 code_checkcode = 0;
477 struct vrequest *treq = NULL;
481 struct afs_fakestat_state fakestat;
484 AFS_STATCNT(afs_close);
485 afs_Trace2(afs_iclSetp, CM_TRACE_CLOSE, ICL_TYPE_POINTER, avc,
486 ICL_TYPE_INT32, aflags);
487 code = afs_CreateReq(&treq, acred);
490 afs_InitFakeStat(&fakestat);
491 code = afs_EvalFakeStat(&avc, &fakestat, treq);
493 afs_PutFakeStat(&fakestat);
494 afs_DestroyReq(treq);
499 if (avc->flockCount) {
500 HandleFlock(avc, LOCK_UN, treq, 0, 1 /*onlymine */ );
503 #if defined(AFS_SGI_ENV)
505 afs_PutFakeStat(&fakestat);
507 afs_DestroyReq(treq);
510 /* unlock any locks for pid - could be wrong for child .. */
511 AFS_RWLOCK((vnode_t *) avc, VRWLOCK_WRITE);
512 # ifdef AFS_SGI65_ENV
513 get_current_flid(&flid);
514 cleanlocks((vnode_t *) avc, flid.fl_pid, flid.fl_sysid);
515 HandleFlock(avc, LOCK_UN, treq, flid.fl_pid, 1 /*onlymine */ );
517 # ifdef AFS_SGI64_ENV
518 cleanlocks((vnode_t *) avc, flp);
519 # else /* AFS_SGI64_ENV */
520 cleanlocks((vnode_t *) avc, u.u_procp->p_epid, u.u_procp->p_sysid);
521 # endif /* AFS_SGI64_ENV */
522 HandleFlock(avc, LOCK_UN, treq, OSI_GET_CURRENT_PID(), 1 /*onlymine */ );
523 # endif /* AFS_SGI65_ENV */
524 /* afs_chkpgoob will drop and re-acquire the global lock. */
525 afs_chkpgoob(&avc->v, btoc(avc->f.m.Length));
526 #elif defined(AFS_SUN5_ENV)
528 /* The vfs layer may call this repeatedly with higher "count"; only
529 * on the last close (i.e. count = 1) we should actually proceed
531 afs_PutFakeStat(&fakestat);
533 afs_DestroyReq(treq);
537 if (avc->flockCount) { /* Release Lock */
538 HandleFlock(avc, LOCK_UN, treq, 0, 1 /*onlymine */ );
541 if (aflags & (FWRITE | FTRUNC)) {
542 if (afs_BBusy() || (AFS_NFSXLATORREQ(acred)) || AFS_IS_DISCONNECTED) {
543 /* do it yourself if daemons are all busy */
544 ObtainWriteLock(&avc->lock, 124);
545 code = afs_StoreOnLastReference(avc, treq);
546 ReleaseWriteLock(&avc->lock);
547 #if defined(AFS_SGI_ENV)
548 AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE);
551 #if defined(AFS_SGI_ENV)
552 AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE);
554 /* at least one daemon is idle, so ask it to do the store.
555 * Also, note that we don't lock it any more... */
556 tb = afs_BQueue(BOP_STORE, avc, 0, 1, acred,
557 (afs_size_t) afs_cr_uid(acred), (afs_size_t) 0,
558 (void *)0, (void *)0, (void *)0);
559 /* sleep waiting for the store to start, then retrieve error code */
560 while ((tb->flags & BUVALID) == 0) {
565 code_checkcode = tb->code_checkcode;
569 /* VNOVNODE is "acceptable" error code from close, since
570 * may happen when deleting a file on another machine while
571 * it is open here. */
572 if (code == VNOVNODE)
575 /* Ensure last closer gets the error. If another thread caused
576 * DoPartialWrite and this thread does not actually store the data,
577 * it may not see the quota error.
579 ObtainWriteLock(&avc->lock, 406);
582 osi_ReleaseVM(avc, acred);
584 /* We don't know what the original raw error code was, so set
585 * 'code' to 0. But we have the afs_CheckCode-translated error
586 * code, so put that in code_checkcode. We cannot just set code
587 * to avc->vc_error, since vc_error is a checkcode-translated
588 * error code, and 'code' is supposed to be a raw error code. */
590 code_checkcode = avc->vc_error;
593 ReleaseWriteLock(&avc->lock);
595 /* some codes merit specific complaint */
597 afs_warnuser("afs: failed to store file (network problems)\n");
600 else if (code == ENOSPC || code_checkcode == ENOSPC) {
602 ("afs: failed to store file (over quota or partition full)\n");
605 else if (code == ENOSPC || code_checkcode == ENOSPC) {
606 afs_warnuser("afs: failed to store file (partition full)\n");
607 } else if (code == EDQUOT || code_checkcode == EDQUOT) {
608 afs_warnuser("afs: failed to store file (over quota)\n");
611 else if (code || code_checkcode)
612 afs_warnuser("afs: failed to store file (%d/%d)\n", code, code_checkcode);
614 /* finally, we flush any text pages lying around here */
618 #if defined(AFS_SGI_ENV)
619 AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE);
620 osi_Assert(avc->opens > 0);
622 /* file open for read */
623 ObtainWriteLock(&avc->lock, 411);
626 osi_ReleaseVM(avc, acred);
629 code_checkcode = avc->vc_error;
632 #if defined(AFS_FBSD80_ENV)
635 afs_int32 opens, is_free, is_gone, is_doomed, iflag;
636 struct vnode *vp = AFSTOV(avc);
638 is_doomed = vp->v_iflag & VI_DOOMED;
639 is_free = vp->v_iflag & VI_FREE;
640 is_gone = vp->v_iflag & VI_DOINGINACT;
644 afs_warn("afs_close avc %p vp %p opens %d free %d doinginact %d doomed %d iflag %d\n",
645 avc, vp, opens, is_free, is_gone, is_doomed, iflag);
649 ReleaseWriteLock(&avc->lock);
652 afs_PutFakeStat(&fakestat);
654 if (code_checkcode) {
655 code = code_checkcode;
657 code = afs_CheckCode(code, treq, 5);
659 afs_DestroyReq(treq);
665 #if defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV)
666 afs_fsync(OSI_VC_DECL(avc), int flag, afs_ucred_t *acred
667 # ifdef AFS_SGI65_ENV
668 , off_t start, off_t stop
669 # endif /* AFS_SGI65_ENV */
671 #else /* !SUN5 && !SGI */
672 afs_fsync(OSI_VC_DECL(avc), afs_ucred_t *acred)
676 struct vrequest *treq = NULL;
680 return avc->vc_error;
682 #if defined(AFS_SUN5_ENV)
683 /* back out if called from NFS server */
684 if (curthread->t_flag & T_DONTPEND)
688 AFS_STATCNT(afs_fsync);
689 afs_Trace1(afs_iclSetp, CM_TRACE_FSYNC, ICL_TYPE_POINTER, avc);
690 if ((code = afs_CreateReq(&treq, acred)))
693 #if defined(AFS_SGI_ENV)
694 AFS_RWLOCK((vnode_t *) avc, VRWLOCK_WRITE);
695 if (flag & FSYNC_INVAL)
696 osi_VM_FSyncInval(avc);
697 #endif /* AFS_SGI_ENV */
699 ObtainSharedLock(&avc->lock, 18);
701 if (avc->execsOrWriters > 0) {
702 if (!AFS_IS_DISCONNECTED && !AFS_IS_DISCON_RW) {
703 /* Your average flush. */
705 /* put the file back */
706 UpgradeSToWLock(&avc->lock, 41);
707 code = afs_StoreAllSegments(avc, treq, AFS_SYNC);
708 ConvertWToSLock(&avc->lock);
710 UpgradeSToWLock(&avc->lock, 711);
711 afs_DisconAddDirty(avc, VDisconWriteFlush, 1);
712 ConvertWToSLock(&avc->lock);
713 } /* if not disconnected */
714 } /* if (avc->execsOrWriters > 0) */
716 #if defined(AFS_SGI_ENV)
717 AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE);
718 if (code == VNOVNODE) {
719 /* syncing an unlinked file! - non-informative to pass an errno
720 * 102 (== VNOVNODE) to user
726 code = afs_CheckCode(code, treq, 33);
727 afs_DestroyReq(treq);
728 ReleaseSharedLock(&avc->lock);