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Postpone dropping fp till both kq_global and kqueue mutexes are

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unlocked. fdrop() closes file descriptor when reference count goes to
zero. Close method for vnodes locks the vnode, resulting in "sleepable
after non-sleepable". For pipes, pipe mutex is before kqueue lock,
causing LOR.

Reported and tested by:	pho
MFC after:	2 weeks
This commit is contained in:
Konstantin Belousov 2009-10-10 14:56:34 +00:00
parent 45623593fb
commit 47d81c1b70
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=197930
1 changed files with 3 additions and 3 deletions
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6
sys/kern/kern_event.c
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@ -1025,13 +1025,13 @@ kqueue_register(struct kqueue *kq, struct kevent *kev, struct thread *td, int wa
/* knote is in the process of changing, wait for it to stablize. */
if (kn != NULL && (kn->kn_status & KN_INFLUX) == KN_INFLUX) {
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
kq->kq_state |= KQ_FLUXWAIT;
msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0);
if (fp != NULL) {
fdrop(fp, td);
fp = NULL;
}
KQ_GLOBAL_UNLOCK(&kq_global, haskqglobal);
kq->kq_state |= KQ_FLUXWAIT;
msleep(kq, &kq->kq_lock, PSOCK | PDROP, "kqflxwt", 0);
goto findkn;
}