Attachment #190730 for bug #203366

Lines 171-178 fifo_open(ap) Link Here

(-)b/sys/fs/fifofs/fifo_vnops.c (-2 / +6 lines)
171	fip->fi_rgen++;	171	fip->fi_rgen++;
172	if (fip->fi_readers == 1) {	172	if (fip->fi_readers == 1) {
173	fpipe->pipe_state &= ~PIPE_EOF;	173	fpipe->pipe_state &= ~PIPE_EOF;
174	if (fip->fi_writers > 0)	174	if (fip->fi_writers > 0) {
175	wakeup(&fip->fi_writers);	175	wakeup(&fip->fi_writers);
		176	pipeselwakeup(fpipe);
		177	}
176	}	178	}
177	fp->f_seqcount = fpipe->pipe_wgen - fip->fi_writers;	179	fp->f_seqcount = fpipe->pipe_wgen - fip->fi_writers;
178	}	180	}
Lines 187-194 fifo_open(ap) Link Here
187	fip->fi_wgen++;	189	fip->fi_wgen++;
188	if (fip->fi_writers == 1) {	190	if (fip->fi_writers == 1) {
189	fpipe->pipe_state &= ~PIPE_EOF;	191	fpipe->pipe_state &= ~PIPE_EOF;
190	if (fip->fi_readers > 0)	192	if (fip->fi_readers > 0) {
191	wakeup(&fip->fi_readers);	193	wakeup(&fip->fi_readers);
		194	pipeselwakeup(fpipe);
		195	}
192	}	196	}
193	}	197	}
194	if ((ap->a_mode & O_NONBLOCK) == 0) {	198	if ((ap->a_mode & O_NONBLOCK) == 0) {

Lines 823-829 pipe_read(fp, uio, active_cred, flags, td) Link Here

(-)b/sys/kern/sys_pipe.c (-9 / +16 lines)
823	}	823	}
824	}	824	}
825		825
826	if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF)	826	/*
		827	* Only wake up writers if there was actually something read.
		828	* Otherwise, when calling read(2) at EOF, a spurious wakeup occurs
		829	* that might lead to issues like PR 203366.
		830	*/
		831	if (nread > 0 &&
		832	(rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF)
827	pipeselwakeup(rpipe);	833	pipeselwakeup(rpipe);
828		834
829	PIPE_UNLOCK(rpipe);	835	PIPE_UNLOCK(rpipe);
Lines 1461-1467 pipe_poll(fp, events, active_cred, td) Link Here
1461		1467
1462	if ((events & POLLINIGNEOF) == 0) {	1468	if ((events & POLLINIGNEOF) == 0) {
1463	if (rpipe->pipe_state & PIPE_EOF) {	1469	if (rpipe->pipe_state & PIPE_EOF) {
1464	revents \|= (events & (POLLIN \| POLLRDNORM));	1470	if (fp->f_flag & FREAD)
		1471	revents \|= (events & (POLLIN \| POLLRDNORM));
1465	if (wpipe->pipe_present != PIPE_ACTIVE \|\|	1472	if (wpipe->pipe_present != PIPE_ACTIVE \|\|
1466	(wpipe->pipe_state & PIPE_EOF))	1473	(wpipe->pipe_state & PIPE_EOF))
1467	revents \|= POLLHUP;	1474	revents \|= POLLHUP;
Lines 1788-1810 filt_pipedetach(struct knote *kn) Link Here
1788	static int	1795	static int
1789	filt_piperead(struct knote *kn, long hint)	1796	filt_piperead(struct knote *kn, long hint)
1790	{	1797	{
		1798	struct file *fp = kn->kn_fp;
1791	struct pipe *rpipe = kn->kn_hook;	1799	struct pipe *rpipe = kn->kn_hook;
1792	struct pipe *wpipe = rpipe->pipe_peer;
1793	int ret;
1794		1800
1795	PIPE_LOCK_ASSERT(rpipe, MA_OWNED);	1801	PIPE_LOCK_ASSERT(rpipe, MA_OWNED);
1796	kn->kn_data = rpipe->pipe_buffer.cnt;	1802	kn->kn_data = rpipe->pipe_buffer.cnt;
1797	if ((kn->kn_data == 0) && (rpipe->pipe_state & PIPE_DIRECTW))	1803	if ((kn->kn_data == 0) && (rpipe->pipe_state & PIPE_DIRECTW))
1798	kn->kn_data = rpipe->pipe_map.cnt;	1804	kn->kn_data = rpipe->pipe_map.cnt;
1799		1805
1800	if ((rpipe->pipe_state & PIPE_EOF) \|\|	1806	if ((rpipe->pipe_state & PIPE_EOF) &&
1801	wpipe->pipe_present != PIPE_ACTIVE \|\|	1807	!((rpipe->pipe_state & PIPE_NAMED) &&
1802	(wpipe->pipe_state & PIPE_EOF)) {	1808	(fp->f_seqcount == rpipe->pipe_wgen))) {
1803	kn->kn_flags \|= EV_EOF;	1809	kn->kn_flags \|= EV_EOF;
1804	return (1);	1810	return (1);
1805	}	1811	}
1806	ret = kn->kn_data > 0;	1812	kn->kn_flags &= ~EV_EOF;
1807	return ret;	1813	return (kn->kn_data > 0);
1808	}	1814	}
1809		1815
1810	/ARGSUSED/	1816	/ARGSUSED/
Lines 1821-1826 filt_pipewrite(struct knote *kn, long hint) Link Here
1821	kn->kn_flags \|= EV_EOF;	1827	kn->kn_flags \|= EV_EOF;
1822	return (1);	1828	return (1);
1823	}	1829	}
		1830	kn->kn_flags &= ~EV_EOF;
1824	kn->kn_data = (wpipe->pipe_buffer.size > 0) ?	1831	kn->kn_data = (wpipe->pipe_buffer.size > 0) ?
1825	(wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) : PIPE_BUF;	1832	(wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) : PIPE_BUF;
1826	if (wpipe->pipe_state & PIPE_DIRECTW)	1833	if (wpipe->pipe_state & PIPE_DIRECTW)

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