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
15 #include <afsconfig.h>
16 #include "afs/param.h"
19 #include "afs/sysincludes.h" /* Standard vendor system headers */
20 #include "afsincludes.h" /* Afs-based standard headers */
21 #include "afs/afs_stats.h" /* statistics */
22 #include "afs/afs_cbqueue.h"
23 #include "afs/nfsclient.h"
24 #include "afs/afs_osidnlc.h"
25 #include "afs/unified_afs.h"
31 /* Static prototypes */
32 static int HandleGetLock(register struct vcache *avc,
33 register struct AFS_FLOCK *af,
34 register struct vrequest *areq, int clid);
35 static int GetFlockCount(struct vcache *avc, struct vrequest *areq);
36 static int lockIdcmp2(struct AFS_FLOCK *flock1, struct vcache *vp,
37 register struct SimpleLocks *alp, int onlymine,
39 static void DoLockWarning(void);
41 /* int clid; * non-zero on SGI, OSF, SunOS, Darwin, xBSD ** XXX ptr type */
43 #if defined(AFS_SUN5_ENV)
45 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
47 proc_t *procp = ttoproc(curthread);
52 slp->pid = procp->p_pid;
54 slp->sysid = procp->p_sysid;
55 slp->pid = procp->p_epid;
60 flock->l_pid = procp->p_pid;
62 flock->l_sysid = procp->p_sysid;
63 flock->l_pid = procp->p_epid;
67 #elif defined(AFS_SGI_ENV)
69 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
71 # if defined(AFS_SGI65_ENV)
73 get_current_flid(&flid);
75 afs_proc_t *procp = OSI_GET_CURRENT_PROCP();
80 slp->sysid = flid.fl_sysid;
82 slp->sysid = OSI_GET_CURRENT_SYSID();
87 flock->l_sysid = flid.fl_sysid;
89 flock->l_sysid = OSI_GET_CURRENT_SYSID();
94 #elif defined(AFS_AIX_ENV)
96 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
98 # if !defined(AFS_AIX32_ENV)
99 afs_proc_t *procp = u.u_procp;
103 # if defined(AFS_AIX41_ENV)
106 # elif defined(AFS_AIX32_ENV)
107 slp->sysid = u.u_sysid;
110 slp->sysid = procp->p_sysid;
111 slp->pid = prcop->p_epid;
114 # if defined(AFS_AIX41_ENV)
116 flock->l_pid = getpid();
117 # elif defined(AFS_AIX32_ENV)
118 flock->l_sysid = u.u_sysid;
119 flock->l_pid = u.u_epid;
121 flock->l_sysid = procp->p_sysid;
122 flock->l_pid = procp->p_epid;
126 #elif defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
128 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
136 #elif defined(AFS_LINUX20_ENV) || defined(AFS_HPUX_ENV)
138 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
143 flock->l_pid = getpid();
146 #elif defined(UKERNEL)
148 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
151 slp->pid = get_user_struct()->u_procp->p_pid;
153 flock->l_pid = get_user_struct()->u_procp->p_pid;
158 lockIdSet(struct AFS_FLOCK *flock, struct SimpleLocks *slp, int clid)
161 slp->pid = u.u_procp->p_pid;
163 flock->l_pid = u.u_procp->p_pid;
168 /* return 1 (true) if specified flock does not match alp (if
169 * specified), or any of the slp structs (if alp == 0)
171 /* I'm not sure that the comparsion of flock->pid to p_ppid
172 * is correct. Should that be a comparision of alp (or slp) ->pid
173 * to p_ppid? Especially in the context of the lower loop, where
174 * the repeated comparison doesn't make much sense...
176 /* onlymine - don't match any locks which are held by my parent */
177 /* clid - only irix 6.5 */
180 lockIdcmp2(struct AFS_FLOCK *flock1, struct vcache *vp,
181 register struct SimpleLocks *alp, int onlymine, int clid)
183 register struct SimpleLocks *slp;
184 #if defined(AFS_SUN5_ENV)
185 register proc_t *procp = ttoproc(curthread);
187 #if !defined(AFS_AIX41_ENV) && !defined(AFS_LINUX20_ENV) && !defined(AFS_SGI65_ENV) && !defined(AFS_DARWIN_ENV) && !defined(AFS_XBSD_ENV)
189 afs_proc_t *procp = curprocp;
190 #elif defined(UKERNEL)
191 afs_proc_t *procp = get_user_struct()->u_procp;
193 afs_proc_t *procp = u.u_procp;
194 #endif /* AFS_SGI64_ENV */
199 #if defined(AFS_AIX_ENV) || defined(AFS_SUN5_ENV) || defined(AFS_SGI_ENV)
200 if (flock1->l_sysid != alp->sysid) {
204 if ((flock1->l_pid == alp->pid) ||
205 #if defined(AFS_AIX41_ENV) || defined(AFS_LINUX20_ENV) || defined(AFS_HPUX_ENV)
206 (!onlymine && (flock1->l_pid == getppid()))
208 #if defined(AFS_SGI65_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
209 /* XXX check this. used to be *only* irix for some reason. */
210 (!onlymine && (flock1->l_pid == clid))
212 (!onlymine && (flock1->l_pid == procp->p_ppid))
221 for (slp = vp->slocks; slp; slp = slp->next) {
222 #if defined(AFS_HAVE_FLOCK_SYSID)
223 if (flock1->l_sysid != slp->sysid) {
227 if (flock1->l_pid == slp->pid) {
231 return (1); /* failure */
235 /* we don't send multiple read flocks to the server, but rather just count
236 them up ourselves. Of course, multiple write locks are incompatible.
238 Note that we should always try to release a lock, even if we have
239 a network problem sending the release command through, since often
240 a lock is released on a close call, when the user can't retry anyway.
242 After we remove it from our structure, the lock will no longer be
243 kept alive, and the server should time it out within a few minutes.
245 94.04.13 add "force" parameter. If a child explicitly unlocks a
246 file, I guess we'll permit it. however, we don't want simple,
247 innocent closes by children to unlock files in the parent process.
249 If called when disconnected support is unabled, the discon_lock must
252 /* clid - nonzero on sgi sunos osf1 only */
254 HandleFlock(register struct vcache *avc, int acom, struct vrequest *areq,
255 pid_t clid, int onlymine)
258 struct SimpleLocks *slp, *tlp, **slpp;
260 struct AFSVolSync tsync;
262 struct AFS_FLOCK flock;
264 AFS_STATCNT(HandleFlock);
265 code = 0; /* default when we don't make any network calls */
266 lockIdSet(&flock, NULL, clid);
268 #if defined(AFS_SGI_ENV)
269 osi_Assert(valusema(&avc->vc_rwlock) <= 0);
270 osi_Assert(OSI_GET_LOCKID() == avc->vc_rwlockid);
272 ObtainWriteLock(&avc->lock, 118);
273 if (acom & LOCK_UN) {
278 /* If the lock is held exclusive, then only the owning process
279 * or a child can unlock it. Use pid and ppid because they are
280 * unique identifiers.
282 if ((avc->flockCount < 0) && (getpid() != avc->ownslock)) {
284 if (onlymine || (getppid() != avc->ownslock)) {
286 if (onlymine || (u.u_procp->p_ppid != avc->ownslock)) {
288 ReleaseWriteLock(&avc->lock);
293 if (lockIdcmp2(&flock, avc, NULL, onlymine, clid)) {
294 ReleaseWriteLock(&avc->lock);
300 if (avc->flockCount == 0) {
301 ReleaseWriteLock(&avc->lock);
305 /* unlock the lock */
306 if (avc->flockCount > 0) {
308 for (slp = *slpp; slp;) {
309 if (!lockIdcmp2(&flock, avc, slp, onlymine, clid)) {
311 tlp = *slpp = slp->next;
312 osi_FreeSmallSpace(slp);
319 } else if (avc->flockCount == -1) {
320 afs_StoreAllSegments(avc, areq, AFS_ASYNC); /* fsync file early */
322 /* And remove the (only) exclusive lock entry from the list... */
323 osi_FreeSmallSpace(avc->slocks);
326 if (avc->flockCount == 0) {
327 if (!AFS_IS_DISCONNECTED) {
329 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK);
331 XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_RELEASELOCK);
333 code = RXAFS_ReleaseLock(tc->id, (struct AFSFid *)
334 &avc->f.fid.Fid, &tsync);
340 (tc, code, &avc->f.fid, areq,
341 AFS_STATS_FS_RPCIDX_RELEASELOCK, SHARED_LOCK, NULL));
343 /*printf("Network is dooooooowwwwwwwnnnnnnn\n");*/
348 while (1) { /* set a new lock */
350 * Upgrading from shared locks to Exclusive and vice versa
351 * is a bit tricky and we don't really support it yet. But
352 * we try to support the common used one which is upgrade
353 * a shared lock to an exclusive for the same process...
355 if ((avc->flockCount > 0 && (acom & LOCK_EX))
356 || (avc->flockCount == -1 && (acom & LOCK_SH))) {
358 * Upgrading from shared locks to an exclusive one:
359 * For now if all the shared locks belong to the
360 * same process then we unlock them on the server
361 * and proceed with the upgrade. Unless we change the
362 * server's locking interface impl we prohibit from
363 * unlocking other processes's shared locks...
364 * Upgrading from an exclusive lock to a shared one:
365 * Again only allowed to be done by the same process.
368 for (slp = *slpp; slp;) {
370 (&flock, avc, slp, 1 /*!onlymine */ , clid)) {
375 tlp = *slpp = slp->next;
376 osi_FreeSmallSpace(slp);
384 if (!code && avc->flockCount == 0) {
385 if (!AFS_IS_DISCONNECTED) {
387 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK);
390 (AFS_STATS_FS_RPCIDX_RELEASELOCK);
393 RXAFS_ReleaseLock(tc->id,
394 (struct AFSFid *)&avc->
401 (tc, code, &avc->f.fid, areq,
402 AFS_STATS_FS_RPCIDX_RELEASELOCK, SHARED_LOCK,
406 } else if (avc->flockCount == -1 && (acom & LOCK_EX)) {
407 if (lockIdcmp2(&flock, avc, NULL, 1, clid)) {
413 /* compatible here, decide if needs to go to file server. If
414 * we've already got the file locked (and thus read-locked, since
415 * we've already checked for compatibility), we shouldn't send
416 * the call through to the server again */
417 if (avc->flockCount == 0) {
418 /* we're the first on our block, send the call through */
419 lockType = ((acom & LOCK_EX) ? LockWrite : LockRead);
420 if (!AFS_IS_DISCONNECTED) {
422 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK);
424 XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_SETLOCK);
426 code = RXAFS_SetLock(tc->id, (struct AFSFid *)
427 &avc->f.fid.Fid, lockType,
434 (tc, code, &avc->f.fid, areq,
435 AFS_STATS_FS_RPCIDX_SETLOCK, SHARED_LOCK,
438 /* XXX - Should probably try and log this when we're
439 * XXX - running with logging enabled. But it's horrid
441 code = 0; /* pretend we worked - ick!!! */
443 code = 0; /* otherwise, pretend things worked */
446 slp = (struct SimpleLocks *)
447 osi_AllocSmallSpace(sizeof(struct SimpleLocks));
448 if (acom & LOCK_EX) {
453 /* Record unique id of process owning exclusive lock. */
454 avc->ownslock = getpid();
457 slp->type = LockWrite;
460 avc->flockCount = -1;
462 slp->type = LockRead;
463 slp->next = avc->slocks;
468 lockIdSet(&flock, slp, clid);
471 /* now, if we got EWOULDBLOCK, and we're supposed to wait, we do */
472 if (((code == EWOULDBLOCK) || (code == EAGAIN) ||
473 (code == UAEWOULDBLOCK) || (code == UAEAGAIN))
474 && !(acom & LOCK_NB)) {
475 /* sleep for a second, allowing interrupts */
476 ReleaseWriteLock(&avc->lock);
477 #if defined(AFS_SGI_ENV)
478 AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE);
480 code = afs_osi_Wait(1000, NULL, 1);
481 #if defined(AFS_SGI_ENV)
482 AFS_RWLOCK((vnode_t *) avc, VRWLOCK_WRITE);
484 ObtainWriteLock(&avc->lock, 120);
486 code = EINTR; /* return this if ^C typed */
493 ReleaseWriteLock(&avc->lock);
494 code = afs_CheckCode(code, areq, 1); /* defeat a buggy AIX optimization */
499 /* warn a user that a lock has been ignored */
500 afs_int32 lastWarnTime = 0; /* this is used elsewhere */
504 register afs_int32 now;
507 AFS_STATCNT(DoLockWarning);
508 /* check if we've already warned someone recently */
509 if (now < lastWarnTime + 120)
512 /* otherwise, it is time to nag the user */
514 #ifdef AFS_LINUX26_ENV
516 ("afs: byte-range locks only enforced for processes on this machine.\n");
519 ("afs: byte-range lock/unlock ignored; make sure no one else is running this program.\n");
524 #if defined(AFS_SGI_ENV) || defined(AFS_DARWIN_ENV) || defined(AFS_XBSD_ENV)
525 int afs_lockctl(struct vcache * avc, struct AFS_FLOCK * af, int acmd,
526 afs_ucred_t * acred, pid_t clid)
529 int afs_lockctl(struct vcache * avc, struct AFS_FLOCK * af, int acmd,
533 struct vrequest treq;
535 struct afs_fakestat_state fakestate;
537 AFS_STATCNT(afs_lockctl);
538 if ((code = afs_InitReq(&treq, acred)))
540 afs_InitFakeStat(&fakestate);
544 code = afs_EvalFakeStat(&avc, &fakestate, &treq);
548 #if (defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV)) && !defined(AFS_SUN58_ENV)
549 if ((acmd == F_GETLK) || (acmd == F_RGETLK)) {
551 if (acmd == F_GETLK) {
553 if (af->l_type == F_UNLCK) {
557 code = HandleGetLock(avc, af, &treq, clid);
558 code = afs_CheckCode(code, &treq, 2); /* defeat buggy AIX optimz */
560 } else if ((acmd == F_SETLK) || (acmd == F_SETLKW)
561 #if (defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV)) && !defined(AFS_SUN58_ENV)
562 || (acmd == F_RSETLK) || (acmd == F_RSETLKW)) {
566 /* this next check is safer when left out, but more applications work
567 * with it in. However, they fail in race conditions. The question is
568 * what to do for people who don't have source to their application;
569 * this way at least, they can get work done */
570 #ifdef AFS_LINUX24_ENV
571 if (af->l_len == OFFSET_MAX)
572 af->l_len = 0; /* since some systems indicate it as EOF */
574 if (af->l_len == 0x7fffffff)
575 af->l_len = 0; /* since some systems indicate it as EOF */
576 #ifdef AFS_LINUX_64BIT_KERNEL
577 if (af->l_len == LONG_MAX)
578 af->l_len = 0; /* since some systems indicate it as EOF */
581 /* Java VMs ask for l_len=(long)-1 regardless of OS/CPU; bottom 32 bits
582 * sometimes get masked off by OS */
583 if ((sizeof(af->l_len) == 8) && (af->l_len == 0x7ffffffffffffffeLL))
585 /* next line makes byte range locks always succeed,
586 * even when they should block */
587 if (af->l_whence != 0 || af->l_start != 0 || af->l_len != 0) {
592 /* otherwise we can turn this into a whole-file flock */
593 if (af->l_type == F_RDLCK)
595 else if (af->l_type == F_WRLCK)
597 else if (af->l_type == F_UNLCK)
600 afs_PutFakeStat(&fakestate);
601 return EINVAL; /* unknown lock type */
603 if (((acmd == F_SETLK)
604 #if (defined(AFS_SGI_ENV) || defined(AFS_SUN5_ENV)) && !defined(AFS_SUN58_ENV)
605 || (acmd == F_RSETLK)
607 ) && code != LOCK_UN)
608 code |= LOCK_NB; /* non-blocking, s.v.p. */
609 #if defined(AFS_DARWIN_ENV)
610 code = HandleFlock(avc, code, &treq, clid, 0 /*!onlymine */ );
611 #elif defined(AFS_SGI_ENV)
612 AFS_RWLOCK((vnode_t *) avc, VRWLOCK_WRITE);
613 code = HandleFlock(avc, code, &treq, clid, 0 /*!onlymine */ );
614 AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE);
616 code = HandleFlock(avc, code, &treq, 0, 0 /*!onlymine */ );
618 code = afs_CheckCode(code, &treq, 3); /* defeat AIX -O bug */
623 afs_PutFakeStat(&fakestate);
630 * Get a description of the first lock which would
631 * block the lock specified. If the specified lock
632 * would succeed, fill in the lock structure with 'F_UNLCK'.
634 * To do that, we have to ask the server for the lock
636 * 1. The file is not locked by this machine.
637 * 2. Asking for write lock, and only the current
638 * PID has the file read locked.
641 HandleGetLock(register struct vcache *avc, register struct AFS_FLOCK *af,
642 register struct vrequest *areq, int clid)
644 register afs_int32 code;
645 struct AFS_FLOCK flock;
647 lockIdSet(&flock, NULL, clid);
649 ObtainWriteLock(&avc->lock, 122);
650 if (avc->flockCount == 0) {
652 * We don't know ourselves, so ask the server. Unfortunately, we
653 * don't know the pid. Not even the server knows the pid. Besides,
654 * the process with the lock is on another machine
656 code = GetFlockCount(avc, areq);
657 if (code == 0 || (af->l_type == F_RDLCK && code > 0)) {
658 af->l_type = F_UNLCK;
662 af->l_type = F_RDLCK;
664 af->l_type = F_WRLCK;
667 #if defined(AFS_HAVE_FLOCK_SYSID)
673 if (af->l_type == F_RDLCK) {
675 * We want a read lock. If there are only
676 * read locks, or we are the one with the
677 * write lock, say it is unlocked.
679 if (avc->flockCount > 0 || /* only read locks */
680 !lockIdcmp2(&flock, avc, NULL, 1, clid)) {
681 af->l_type = F_UNLCK;
685 /* one write lock, but who? */
686 af->l_type = F_WRLCK; /* not us, so lock would block */
687 if (avc->slocks) { /* we know who, so tell */
688 af->l_pid = avc->slocks->pid;
689 #if defined(AFS_HAVE_FLOCK_SYSID)
690 af->l_sysid = avc->slocks->sysid;
693 af->l_pid = 0; /* XXX can't happen?? */
694 #if defined(AFS_HAVE_FLOCK_SYSID)
702 * Ok, we want a write lock. If there is a write lock
703 * already, and it is not this process, we fail.
705 if (avc->flockCount < 0) {
706 if (lockIdcmp2(&flock, avc, NULL, 1, clid)) {
707 af->l_type = F_WRLCK;
709 af->l_pid = avc->slocks->pid;
710 #if defined(AFS_HAVE_FLOCK_SYSID)
711 af->l_sysid = avc->slocks->sysid;
714 af->l_pid = 0; /* XXX can't happen?? */
715 #if defined(AFS_HAVE_FLOCK_SYSID)
721 /* we are the one with the write lock */
722 af->l_type = F_UNLCK;
727 * Want a write lock, and we know there are read locks.
728 * If there is more than one, or it isn't us, we cannot lock.
730 if ((avc->flockCount > 1)
731 || lockIdcmp2(&flock, avc, NULL, 1, clid)) {
732 struct SimpleLocks *slp;
734 af->l_type = F_RDLCK;
736 #if defined(AFS_HAVE_FLOCK_SYSID)
739 /* find a pid that isn't our own */
740 for (slp = avc->slocks; slp; slp = slp->next) {
741 if (lockIdcmp2(&flock, NULL, slp, 1, clid)) {
742 af->l_pid = slp->pid;
743 #if defined(AFS_HAVE_FLOCK_SYSID)
744 af->l_sysid = avc->slocks->sysid;
753 * Ok, we want a write lock. If there is a write lock
754 * already, and it is not this process, we fail.
756 if (avc->flockCount < 0) {
757 if (lockIdcmp2(&flock, avc, NULL, 1, clid)) {
758 af->l_type = F_WRLCK;
760 af->l_pid = avc->slocks->pid;
761 #if defined(AFS_HAVE_FLOCK_SYSID)
762 af->l_sysid = avc->slocks->sysid;
765 af->l_pid = 0; /* XXX can't happen?? */
766 #if defined(AFS_HAVE_FLOCK_SYSID)
772 /* we are the one with the write lock */
773 af->l_type = F_UNLCK;
778 * Want a write lock, and we know there are read locks.
779 * If there is more than one, or it isn't us, we cannot lock.
781 if ((avc->flockCount > 1)
782 || lockIdcmp2(&flock, avc, NULL, 1, clid)) {
783 struct SimpleLocks *slp;
784 af->l_type = F_RDLCK;
786 #if defined(AFS_HAVE_FLOCK_SYSID)
789 /* find a pid that isn't our own */
790 for (slp = avc->slocks; slp; slp = slp->next) {
791 if (lockIdcmp2(&flock, NULL, slp, 1, clid)) {
792 af->l_pid = slp->pid;
793 #if defined(AFS_HAVE_FLOCK_SYSID)
794 af->l_sysid = avc->slocks->sysid;
803 * Want a write lock, and there is just one read lock, and it
804 * is this process with a read lock. Ask the server if there
805 * are any more processes with the file locked.
807 code = GetFlockCount(avc, areq);
808 if (code == 0 || code == 1) {
809 af->l_type = F_UNLCK;
813 af->l_type = F_RDLCK;
815 af->l_type = F_WRLCK;
817 #if defined(AFS_HAVE_FLOCK_SYSID)
824 af->l_len = 0; /* to end of file */
827 ReleaseWriteLock(&avc->lock);
831 /* Get the 'flock' count from the server. This comes back in a 'spare'
832 * field from a GetStatus RPC. If we have any problems with the RPC,
833 * we lie and say the file is unlocked. If we ask any 'old' fileservers,
834 * the spare field will be a zero, saying the file is unlocked. This is
835 * OK, as a further 'lock' request will do the right thing.
838 GetFlockCount(struct vcache *avc, struct vrequest *areq)
840 register struct afs_conn *tc;
841 register afs_int32 code;
842 struct AFSFetchStatus OutStatus;
843 struct AFSCallBack CallBack;
844 struct AFSVolSync tsync;
847 temp = areq->flags & O_NONBLOCK;
848 areq->flags |= O_NONBLOCK;
850 /* If we're disconnected, lie and say that we've got no locks. Ick */
851 if (AFS_IS_DISCONNECTED)
855 tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK);
857 XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_FETCHSTATUS);
860 RXAFS_FetchStatus(tc->id, (struct AFSFid *)&avc->f.fid.Fid,
861 &OutStatus, &CallBack, &tsync);
867 (tc, code, &avc->f.fid, areq, AFS_STATS_FS_RPCIDX_FETCHSTATUS,
871 areq->flags &= ~O_NONBLOCK;
874 return (0); /* failed, say it is 'unlocked' */
876 return ((int)OutStatus.lockCount);