/* 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;
}
