/* Try to invalidate pages, for "fs flush" or "fs flushv"; or * try to free pages, when deleting a file. * * Locking: the vcache entry's lock is held. It may be dropped and * re-obtained. * * Since we drop and re-obtain the lock, we can't guarantee that there won't * be some pages around when we return, newly created by concurrent activity. */ void osi_VM_TryToSmush(struct vcache *avc, afs_ucred_t *acred, int sync) { ReleaseWriteLock(&avc->lock); AFS_GUNLOCK(); /* current remapf restriction - cannot have VOP_RWLOCK */ osi_Assert(OSI_GET_LOCKID() != avc->vc_rwlockid); if (((vnode_t *) avc)->v_type == VREG && AFS_VN_MAPPED(((vnode_t *) avc))) remapf(((vnode_t *) avc), 0, 0); PTOSSVP(AFSTOV(avc), (off_t) 0, (off_t) MAXLONG); AFS_GLOCK(); ObtainWriteLock(&avc->lock, 62); }
/* Try to store pages to cache, in order to store a file back to the server. * * Locking: the vcache entry's lock is held. It will usually be dropped and * re-obtained. */ void osi_VM_StoreAllSegments(struct vcache *avc) { int error; osi_Assert(valusema(&avc->vc_rwlock) <= 0); osi_Assert(OSI_GET_LOCKID() == avc->vc_rwlockid); osi_Assert(avc->vrefCount > 0); ReleaseWriteLock(&avc->lock); /* We may call back into AFS via: * pflushvp->chunkpush->do_pdflush->mp_afs_bmap */ AFS_GUNLOCK(); /* Write out dirty pages list to avoid B_DELWRI buffers. */ while (VN_GET_DPAGES((vnode_t *) avc)) { pdflush(AFSTOV(avc), 0); } PFLUSHVP(AFSTOV(avc), (off_t) avc->f.m.Length, (off_t) 0, error); AFS_GLOCK(); if (error) { /* * If this fails (due to quota overage, etc.) * what can we do?? we need to sure that * that the VM cache is cleared of dirty pages * We note that pinvalfree ignores write errors & otherwise * does what we want (we don't use this normally since * it also unhashes pages ..) */ PINVALFREE((vnode_t *) avc, avc->f.m.Length); } ObtainWriteLock(&avc->lock, 121); if (error && avc->f.m.LinkCount) cmn_err(CE_WARN, "AFS:Failed to push back pages for vnode 0x%x error %d (from afs_StoreOnLastReference)", avc, error); }
/* clid - nonzero on sgi sunos osf1 only */ int HandleFlock(struct vcache *avc, int acom, struct vrequest *areq, pid_t clid, int onlymine) { struct afs_conn *tc; struct SimpleLocks *slp, *tlp, **slpp; afs_int32 code; struct AFSVolSync tsync; afs_int32 lockType; struct AFS_FLOCK flock; XSTATS_DECLS; AFS_STATCNT(HandleFlock); code = 0; /* default when we don't make any network calls */ lockIdSet(&flock, NULL, clid); #if defined(AFS_SGI_ENV) osi_Assert(valusema(&avc->vc_rwlock) <= 0); osi_Assert(OSI_GET_LOCKID() == avc->vc_rwlockid); #endif ObtainWriteLock(&avc->lock, 118); if (acom & LOCK_UN) { int stored_segments = 0; retry_unlock: /* defect 3083 */ #ifdef AFS_AIX_ENV /* If the lock is held exclusive, then only the owning process * or a child can unlock it. Use pid and ppid because they are * unique identifiers. */ if ((avc->flockCount < 0) && (getpid() != avc->ownslock)) { #ifdef AFS_AIX41_ENV if (onlymine || (getppid() != avc->ownslock)) { #else if (onlymine || (u.u_procp->p_ppid != avc->ownslock)) { #endif ReleaseWriteLock(&avc->lock); return 0; } } #endif if (lockIdcmp2(&flock, avc, NULL, onlymine, clid)) { ReleaseWriteLock(&avc->lock); return 0; } #ifdef AFS_AIX_ENV avc->ownslock = 0; #endif if (avc->flockCount == 0) { ReleaseWriteLock(&avc->lock); return 0 /*ENOTTY*/; /* no lock held */ } /* unlock the lock */ if (avc->flockCount > 0) { slpp = &avc->slocks; for (slp = *slpp; slp;) { if (!lockIdcmp2(&flock, avc, slp, onlymine, clid)) { avc->flockCount--; tlp = *slpp = slp->next; osi_FreeSmallSpace(slp); slp = tlp; } else { slpp = &slp->next; slp = *slpp; } } } else if (avc->flockCount == -1) { if (!stored_segments) { afs_StoreAllSegments(avc, areq, AFS_SYNC | AFS_VMSYNC); /* fsync file early */ /* afs_StoreAllSegments can drop and reacquire the write lock * on avc and GLOCK, so the flocks may be completely different * now. Go back and perform all checks again. */ stored_segments = 1; goto retry_unlock; } avc->flockCount = 0; /* And remove the (only) exclusive lock entry from the list... */ osi_FreeSmallSpace(avc->slocks); avc->slocks = 0; } if (avc->flockCount == 0) { if (!AFS_IS_DISCONNECTED) { struct rx_connection *rxconn; do { tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK, &rxconn); if (tc) { XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_RELEASELOCK); RX_AFS_GUNLOCK(); code = RXAFS_ReleaseLock(rxconn, (struct AFSFid *) &avc->f.fid.Fid, &tsync); RX_AFS_GLOCK(); XSTATS_END_TIME; } else code = -1; } while (afs_Analyze (tc, rxconn, code, &avc->f.fid, areq, AFS_STATS_FS_RPCIDX_RELEASELOCK, SHARED_LOCK, NULL)); } else { /*printf("Network is dooooooowwwwwwwnnnnnnn\n");*/ code = ENETDOWN; } } } else { while (1) { /* set a new lock */ /* * Upgrading from shared locks to Exclusive and vice versa * is a bit tricky and we don't really support it yet. But * we try to support the common used one which is upgrade * a shared lock to an exclusive for the same process... */ if ((avc->flockCount > 0 && (acom & LOCK_EX)) || (avc->flockCount == -1 && (acom & LOCK_SH))) { /* * Upgrading from shared locks to an exclusive one: * For now if all the shared locks belong to the * same process then we unlock them on the server * and proceed with the upgrade. Unless we change the * server's locking interface impl we prohibit from * unlocking other processes's shared locks... * Upgrading from an exclusive lock to a shared one: * Again only allowed to be done by the same process. */ slpp = &avc->slocks; for (slp = *slpp; slp;) { if (!lockIdcmp2 (&flock, avc, slp, 1 /*!onlymine */ , clid)) { if (acom & LOCK_EX) avc->flockCount--; else avc->flockCount = 0; tlp = *slpp = slp->next; osi_FreeSmallSpace(slp); slp = tlp; } else { code = EWOULDBLOCK; slpp = &slp->next; slp = *slpp; } } if (!code && avc->flockCount == 0) { if (!AFS_IS_DISCONNECTED) { struct rx_connection *rxconn; do { tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK, &rxconn); if (tc) { XSTATS_START_TIME (AFS_STATS_FS_RPCIDX_RELEASELOCK); RX_AFS_GUNLOCK(); code = RXAFS_ReleaseLock(rxconn, (struct AFSFid *)&avc-> f.fid.Fid, &tsync); RX_AFS_GLOCK(); XSTATS_END_TIME; } else code = -1; } while (afs_Analyze (tc, rxconn, code, &avc->f.fid, areq, AFS_STATS_FS_RPCIDX_RELEASELOCK, SHARED_LOCK, NULL)); } } } else if (avc->flockCount == -1 && (acom & LOCK_EX)) { if (lockIdcmp2(&flock, avc, NULL, 1, clid)) { code = EWOULDBLOCK; } else { code = 0; /* We've just re-grabbed an exclusive lock, so we don't * need to contact the fileserver, and we don't need to * add the lock to avc->slocks (since we already have a * lock there). So, we are done. */ break; } } if (code == 0) { /* compatible here, decide if needs to go to file server. If * we've already got the file locked (and thus read-locked, since * we've already checked for compatibility), we shouldn't send * the call through to the server again */ if (avc->flockCount == 0) { struct rx_connection *rxconn; /* we're the first on our block, send the call through */ lockType = ((acom & LOCK_EX) ? LockWrite : LockRead); if (!AFS_IS_DISCONNECTED) { do { tc = afs_Conn(&avc->f.fid, areq, SHARED_LOCK, &rxconn); if (tc) { XSTATS_START_TIME(AFS_STATS_FS_RPCIDX_SETLOCK); RX_AFS_GUNLOCK(); code = RXAFS_SetLock(rxconn, (struct AFSFid *) &avc->f.fid.Fid, lockType, &tsync); RX_AFS_GLOCK(); XSTATS_END_TIME; } else code = -1; } while (afs_Analyze (tc, rxconn, code, &avc->f.fid, areq, AFS_STATS_FS_RPCIDX_SETLOCK, SHARED_LOCK, NULL)); if ((lockType == LockWrite) && (code == VREADONLY)) code = EBADF; /* per POSIX; VREADONLY == EROFS */ } else /* XXX - Should probably try and log this when we're * XXX - running with logging enabled. But it's horrid */ code = 0; /* pretend we worked - ick!!! */ } else code = 0; /* otherwise, pretend things worked */ } if (code == 0) { slp = (struct SimpleLocks *) osi_AllocSmallSpace(sizeof(struct SimpleLocks)); if (acom & LOCK_EX) { /* defect 3083 */ #ifdef AFS_AIX_ENV /* Record unique id of process owning exclusive lock. */ avc->ownslock = getpid(); #endif slp->type = LockWrite; slp->next = NULL; avc->slocks = slp; avc->flockCount = -1; } else { slp->type = LockRead; slp->next = avc->slocks; avc->slocks = slp; avc->flockCount++; } lockIdSet(&flock, slp, clid); break; } /* now, if we got EWOULDBLOCK, and we're supposed to wait, we do */ if (((code == EWOULDBLOCK) || (code == EAGAIN) || (code == UAEWOULDBLOCK) || (code == UAEAGAIN)) && !(acom & LOCK_NB)) { /* sleep for a second, allowing interrupts */ ReleaseWriteLock(&avc->lock); #if defined(AFS_SGI_ENV) AFS_RWUNLOCK((vnode_t *) avc, VRWLOCK_WRITE); #endif code = afs_osi_Wait(1000, NULL, 1); #if defined(AFS_SGI_ENV) AFS_RWLOCK((vnode_t *) avc, VRWLOCK_WRITE); #endif ObtainWriteLock(&avc->lock, 120); if (code) { code = EINTR; /* return this if ^C typed */ break; } } else break; } /* while loop */ } ReleaseWriteLock(&avc->lock); code = afs_CheckCode(code, areq, 1); /* defeat a buggy AIX optimization */ return code; } /* warn a user that a lock has been ignored */ afs_int32 lastWarnTime = 0; /* this is used elsewhere */ static afs_int32 lastWarnPid = 0; static void DoLockWarning(afs_ucred_t * acred) { afs_int32 now; pid_t pid = MyPidxx2Pid(MyPidxx); char *procname; now = osi_Time(); AFS_STATCNT(DoLockWarning); /* check if we've already warned this user recently */ if (!((now < lastWarnTime + 120) && (lastWarnPid == pid))) { procname = afs_osi_Alloc(256); if (!procname) return; /* Copies process name to allocated procname, see osi_machdeps for details of macro */ osi_procname(procname, 256); procname[255] = '\0'; /* otherwise, it is time to nag the user */ lastWarnTime = now; lastWarnPid = pid; #ifdef AFS_LINUX26_ENV afs_warnuser ("afs: byte-range locks only enforced for processes on this machine (pid %d (%s), user %ld).\n", pid, procname, (long)afs_cr_uid(acred)); #else afs_warnuser ("afs: byte-range lock/unlock ignored; make sure no one else is running this program (pid %d (%s), user %ld).\n", pid, procname, (long)afs_cr_uid(acred)); #endif afs_osi_Free(procname, 256); } return; }