merge pipe and fifo implementations

Also reviewed by: jhb, jilles (initial revision)
Tested by: pho, jilles

Submitted by:	gianni
Reviewed by:	bde

1 files changed, 145 insertions, 47 deletions

diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c
index 0cb4fce..4f0217d 100644
--- a/sys/kern/sys_pipe.c
+++ b/sys/kern/sys_pipe.c
@@ -1,5 +1,6 @@
 /*-
  * Copyright (c) 1996 John S. Dyson
+ * Copyright (c) 2012 Giovanni Trematerra
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -128,6 +129,8 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_page.h>
 #include <vm/uma.h>
 
+#include <fs/fifofs/fifo.h>
+
 /*
  * Use this define if you want to disable *fancy* VM things.  Expect an
  * approx 30% decrease in transfer rate.  This could be useful for
@@ -135,6 +138,9 @@ __FBSDID("$FreeBSD$");
  */
 /* #define PIPE_NODIRECT */
 
+#define PIPE_PEER(pipe)	\
+	(((pipe)->pipe_state & PIPE_NAMED) ? (pipe) : ((pipe)->pipe_peer))
+
 /*
  * interfaces to the outside world
  */
@@ -147,7 +153,7 @@ static fo_kqfilter_t	pipe_kqfilter;
 static fo_stat_t	pipe_stat;
 static fo_close_t	pipe_close;
 
-static struct fileops pipeops = {
+struct fileops pipeops = {
 	.fo_read = pipe_read,
 	.fo_write = pipe_write,
 	.fo_truncate = pipe_truncate,
@@ -162,9 +168,16 @@ static struct fileops pipeops = {
 };
 
 static void	filt_pipedetach(struct knote *kn);
+static void	filt_pipedetach_notsup(struct knote *kn);
+static int	filt_pipenotsup(struct knote *kn, long hint);
 static int	filt_piperead(struct knote *kn, long hint);
 static int	filt_pipewrite(struct knote *kn, long hint);
 
+static struct filterops pipe_nfiltops = {
+	.f_isfd = 1,
+	.f_detach = filt_pipedetach_notsup,
+	.f_event = filt_pipenotsup
+};
 static struct filterops pipe_rfiltops = {
 	.f_isfd = 1,
 	.f_detach = filt_pipedetach,
@@ -208,6 +221,7 @@ static void pipeinit(void *dummy __unused);
 static void pipeclose(struct pipe *cpipe);
 static void pipe_free_kmem(struct pipe *cpipe);
 static int pipe_create(struct pipe *pipe, int backing);
+static int pipe_paircreate(struct thread *td, struct pipepair **p_pp);
 static __inline int pipelock(struct pipe *cpipe, int catch);
 static __inline void pipeunlock(struct pipe *cpipe);
 static __inline void pipeselwakeup(struct pipe *cpipe);
@@ -317,20 +331,14 @@ pipe_zone_fini(void *mem, int size)
 	mtx_destroy(&pp->pp_mtx);
 }
 
-/*
- * The pipe system call for the DTYPE_PIPE type of pipes.  If we fail, let
- * the zone pick up the pieces via pipeclose().
- */
-int
-kern_pipe(struct thread *td, int fildes[2])
+static int
+pipe_paircreate(struct thread *td, struct pipepair **p_pp)
 {
-	struct filedesc *fdp = td->td_proc->p_fd;
-	struct file *rf, *wf;
 	struct pipepair *pp;
 	struct pipe *rpipe, *wpipe;
-	int fd, error;
+	int error;
 
-	pp = uma_zalloc(pipe_zone, M_WAITOK);
+	*p_pp = pp = uma_zalloc(pipe_zone, M_WAITOK);
 #ifdef MAC
 	/*
 	 * The MAC label is shared between the connected endpoints.  As a
@@ -356,7 +364,59 @@ kern_pipe(struct thread *td, int fildes[2])
 
 	rpipe->pipe_state |= PIPE_DIRECTOK;
 	wpipe->pipe_state |= PIPE_DIRECTOK;
+	return (0);
+}
+
+int
+pipe_named_ctor(struct pipe **ppipe, struct thread *td)
+{
+	struct pipepair *pp;
+	int error;
+
+	error = pipe_paircreate(td, &pp);
+	if (error != 0)
+		return (error);
+	pp->pp_rpipe.pipe_state |= PIPE_NAMED;
+	*ppipe = &pp->pp_rpipe;
+	return (0);
+}
+
+void
+pipe_dtor(struct pipe *dpipe)
+{
+	ino_t ino;
+
+	ino = dpipe->pipe_ino;
+	funsetown(&dpipe->pipe_sigio);
+	pipeclose(dpipe);
+	if (dpipe->pipe_state & PIPE_NAMED) {
+		dpipe = dpipe->pipe_peer;
+		funsetown(&dpipe->pipe_sigio);
+		pipeclose(dpipe);
+	}
+	if (ino != 0 && ino != (ino_t)-1)
+		free_unr(pipeino_unr, ino);
+}
+
+/*
+ * The pipe system call for the DTYPE_PIPE type of pipes.  If we fail, let
+ * the zone pick up the pieces via pipeclose().
+ */
+int
+kern_pipe(struct thread *td, int fildes[2])
+{
+	struct filedesc *fdp; 
+	struct file *rf, *wf;
+	struct pipe *rpipe, *wpipe;
+	struct pipepair *pp;
+	int fd, error;
 
+	fdp = td->td_proc->p_fd;
+	error = pipe_paircreate(td, &pp);
+	if (error != 0)
+		return (error);
+	rpipe = &pp->pp_rpipe;
+	wpipe = &pp->pp_wpipe;
 	error = falloc(td, &rf, &fd, 0);
 	if (error) {
 		pipeclose(rpipe);
@@ -582,11 +642,12 @@ pipe_read(fp, uio, active_cred, flags, td)
 	struct thread *td;
 	int flags;
 {
-	struct pipe *rpipe = fp->f_data;
+	struct pipe *rpipe;
 	int error;
 	int nread = 0;
 	u_int size;
 
+	rpipe = fp->f_data;
 	PIPE_LOCK(rpipe);
 	++rpipe->pipe_busy;
 	error = pipelock(rpipe, 1);
@@ -960,13 +1021,12 @@ pipe_write(fp, uio, active_cred, flags, td)
 	struct thread *td;
 	int flags;
 {
-	int error = 0;
+	int error;
 	size_t desiredsize, orig_resid;
 	struct pipe *wpipe, *rpipe;
 
 	rpipe = fp->f_data;
-	wpipe = rpipe->pipe_peer;
-
+	wpipe = PIPE_PEER(rpipe);
 	PIPE_LOCK(rpipe);
 	error = pipelock(wpipe, 1);
 	if (error) {
@@ -1243,6 +1303,9 @@ pipe_truncate(fp, length, active_cred, td)
 	struct thread *td;
 {
 
+	/* For named pipes call the vnode operation. */
+	if (fp->f_vnode != NULL)
+		return (vnops.fo_truncate(fp, length, active_cred, td));
 	return (EINVAL);
 }
 
@@ -1285,6 +1348,11 @@ pipe_ioctl(fp, cmd, data, active_cred, td)
 		break;
 
 	case FIONREAD:
+		if (!(fp->f_flag & FREAD)) {
+			*(int *)data = 0;
+			PIPE_UNLOCK(mpipe);
+			return (0);
+		}
 		if (mpipe->pipe_state & PIPE_DIRECTW)
 			*(int *)data = mpipe->pipe_map.cnt;
 		else
@@ -1327,26 +1395,28 @@ pipe_poll(fp, events, active_cred, td)
 	struct ucred *active_cred;
 	struct thread *td;
 {
-	struct pipe *rpipe = fp->f_data;
+	struct pipe *rpipe;
 	struct pipe *wpipe;
-	int revents = 0;
+	int levents, revents;
 #ifdef MAC
 	int error;
 #endif
 
-	wpipe = rpipe->pipe_peer;
+	revents = 0;
+	rpipe = fp->f_data;
+	wpipe = PIPE_PEER(rpipe);
 	PIPE_LOCK(rpipe);
 #ifdef MAC
 	error = mac_pipe_check_poll(active_cred, rpipe->pipe_pair);
 	if (error)
 		goto locked_error;
 #endif
-	if (events & (POLLIN | POLLRDNORM))
+	if (fp->f_flag & FREAD && events & (POLLIN | POLLRDNORM))
 		if ((rpipe->pipe_state & PIPE_DIRECTW) ||
 		    (rpipe->pipe_buffer.cnt > 0))
 			revents |= events & (POLLIN | POLLRDNORM);
 
-	if (events & (POLLOUT | POLLWRNORM))
+	if (fp->f_flag & FWRITE && events & (POLLOUT | POLLWRNORM))
 		if (wpipe->pipe_present != PIPE_ACTIVE ||
 		    (wpipe->pipe_state & PIPE_EOF) ||
 		    (((wpipe->pipe_state & PIPE_DIRECTW) == 0) &&
@@ -1354,6 +1424,12 @@ pipe_poll(fp, events, active_cred, td)
 			 wpipe->pipe_buffer.size == 0)))
 			revents |= events & (POLLOUT | POLLWRNORM);
 
+	levents = events &
+	    (POLLIN | POLLINIGNEOF | POLLPRI | POLLRDNORM | POLLRDBAND);
+	if (rpipe->pipe_state & PIPE_NAMED && fp->f_flag & FREAD && levents &&
+	    fifo_iseof(fp))
+		events |= POLLINIGNEOF;
+
 	if ((events & POLLINIGNEOF) == 0) {
 		if (rpipe->pipe_state & PIPE_EOF) {
 			revents |= (events & (POLLIN | POLLRDNORM));
@@ -1364,13 +1440,13 @@ pipe_poll(fp, events, active_cred, td)
 	}
 
 	if (revents == 0) {
-		if (events & (POLLIN | POLLRDNORM)) {
+		if (fp->f_flag & FREAD && events & (POLLIN | POLLRDNORM)) {
 			selrecord(td, &rpipe->pipe_sel);
 			if (SEL_WAITING(&rpipe->pipe_sel))
 				rpipe->pipe_state |= PIPE_SEL;
 		}
 
-		if (events & (POLLOUT | POLLWRNORM)) {
+		if (fp->f_flag & FWRITE && events & (POLLOUT | POLLWRNORM)) {
 			selrecord(td, &wpipe->pipe_sel);
 			if (SEL_WAITING(&wpipe->pipe_sel))
 				wpipe->pipe_state |= PIPE_SEL;
@@ -1410,6 +1486,13 @@ pipe_stat(fp, ub, active_cred, td)
 		return (error);
 	}
 #endif
+
+	/* For named pipes ask the underlying filesystem. */
+	if (pipe->pipe_state & PIPE_NAMED) {
+		PIPE_UNLOCK(pipe);
+		return (vnops.fo_stat(fp, ub, active_cred, td));
+	}
+
 	/*
 	 * Lazily allocate an inode number for the pipe.  Most pipe
 	 * users do not call fstat(2) on the pipe, which means that
@@ -1456,12 +1539,12 @@ pipe_close(fp, td)
 	struct file *fp;
 	struct thread *td;
 {
-	struct pipe *cpipe = fp->f_data;
 
+	if (fp->f_vnode != NULL) 
+		return vnops.fo_close(fp, td);
 	fp->f_ops = &badfileops;
+	pipe_dtor(fp->f_data);
 	fp->f_data = NULL;
-	funsetown(&cpipe->pipe_sigio);
-	pipeclose(cpipe);
 	return (0);
 }
 
@@ -1498,7 +1581,6 @@ pipeclose(cpipe)
 {
 	struct pipepair *pp;
 	struct pipe *ppipe;
-	ino_t ino;
 
 	KASSERT(cpipe != NULL, ("pipeclose: cpipe == NULL"));
 
@@ -1557,12 +1639,6 @@ pipeclose(cpipe)
 	knlist_destroy(&cpipe->pipe_sel.si_note);
 
 	/*
-	 * Postpone the destroy of the fake inode number allocated for
-	 * our end, until pipe mtx is unlocked.
-	 */
-	ino = cpipe->pipe_ino;
-
-	/*
 	 * If both endpoints are now closed, release the memory for the
 	 * pipe pair.  If not, unlock.
 	 */
@@ -1574,9 +1650,6 @@ pipeclose(cpipe)
 		uma_zfree(pipe_zone, cpipe->pipe_pair);
 	} else
 		PIPE_UNLOCK(cpipe);
-
-	if (ino != 0 && ino != (ino_t)-1)
-		free_unr(pipeino_unr, ino);
 }
 
 /*ARGSUSED*/
@@ -1585,7 +1658,20 @@ pipe_kqfilter(struct file *fp, struct knote *kn)
 {
 	struct pipe *cpipe;
 
-	cpipe = kn->kn_fp->f_data;
+	/*
+	 * If a filter is requested that is not supported by this file
+	 * descriptor, don't return an error, but also don't ever generate an
+	 * event.
+	 */
+	if ((kn->kn_filter == EVFILT_READ) && !(fp->f_flag & FREAD)) {
+		kn->kn_fop = &pipe_nfiltops;
+		return (0);
+	}
+	if ((kn->kn_filter == EVFILT_WRITE) && !(fp->f_flag & FWRITE)) {
+		kn->kn_fop = &pipe_nfiltops;
+		return (0);
+	}
+	cpipe = fp->f_data;
 	PIPE_LOCK(cpipe);
 	switch (kn->kn_filter) {
 	case EVFILT_READ:
@@ -1598,13 +1684,14 @@ pipe_kqfilter(struct file *fp, struct knote *kn)
 			PIPE_UNLOCK(cpipe);
 			return (EPIPE);
 		}
-		cpipe = cpipe->pipe_peer;
+		cpipe = PIPE_PEER(cpipe);
 		break;
 	default:
 		PIPE_UNLOCK(cpipe);
 		return (EINVAL);
 	}
 
+	kn->kn_hook = cpipe; 
 	knlist_add(&cpipe->pipe_sel.si_note, kn, 1);
 	PIPE_UNLOCK(cpipe);
 	return (0);
@@ -1613,11 +1700,9 @@ pipe_kqfilter(struct file *fp, struct knote *kn)
 static void
 filt_pipedetach(struct knote *kn)
 {
-	struct pipe *cpipe = (struct pipe *)kn->kn_fp->f_data;
+	struct pipe *cpipe = kn->kn_hook;
 
 	PIPE_LOCK(cpipe);
-	if (kn->kn_filter == EVFILT_WRITE)
-		cpipe = cpipe->pipe_peer;
 	knlist_remove(&cpipe->pipe_sel.si_note, kn, 1);
 	PIPE_UNLOCK(cpipe);
 }
@@ -1626,7 +1711,7 @@ filt_pipedetach(struct knote *kn)
 static int
 filt_piperead(struct knote *kn, long hint)
 {
-	struct pipe *rpipe = kn->kn_fp->f_data;
+	struct pipe *rpipe = kn->kn_hook;
 	struct pipe *wpipe = rpipe->pipe_peer;
 	int ret;
 
@@ -1651,15 +1736,15 @@ filt_piperead(struct knote *kn, long hint)
 static int
 filt_pipewrite(struct knote *kn, long hint)
 {
-	struct pipe *rpipe = kn->kn_fp->f_data;
-	struct pipe *wpipe = rpipe->pipe_peer;
-
-	PIPE_LOCK(rpipe);
+	struct pipe *wpipe;
+   
+	wpipe = kn->kn_hook;
+	PIPE_LOCK(wpipe);
 	if (wpipe->pipe_present != PIPE_ACTIVE ||
 	    (wpipe->pipe_state & PIPE_EOF)) {
 		kn->kn_data = 0;
 		kn->kn_flags |= EV_EOF;
-		PIPE_UNLOCK(rpipe);
+		PIPE_UNLOCK(wpipe);
 		return (1);
 	}
 	kn->kn_data = (wpipe->pipe_buffer.size > 0) ?
@@ -1667,6 +1752,19 @@ filt_pipewrite(struct knote *kn, long hint)
 	if (wpipe->pipe_state & PIPE_DIRECTW)
 		kn->kn_data = 0;
 
-	PIPE_UNLOCK(rpipe);
+	PIPE_UNLOCK(wpipe);
 	return (kn->kn_data >= PIPE_BUF);
 }
+
+static void
+filt_pipedetach_notsup(struct knote *kn)
+{
+
+}
+
+static int
+filt_pipenotsup(struct knote *kn, long hint)
+{
+
+	return (0);
+}