PSARC/2009/380 STREAMS and Character Device Coexistence

6858144 implement STREAMS/character device coexistence (PSARC 2009/380)

3 files changed, 33 insertions, 25 deletions

diff --git a/usr/src/uts/common/fs/specfs/specsubr.c b/usr/src/uts/common/fs/specfs/specsubr.c
index 9ae689c696..c43b4bd921 100644
--- a/usr/src/uts/common/fs/specfs/specsubr.c
+++ b/usr/src/uts/common/fs/specfs/specsubr.c
@@ -19,7 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -37,8 +37,6 @@
  */
 
 
-#pragma ident	"%Z%%M%	%I%	%E% SMI"
-
 #include <sys/types.h>
 #include <sys/t_lock.h>
 #include <sys/param.h>
@@ -740,7 +738,7 @@ spec_maxoffset(struct vnode *vp)
 	struct snode *sp = VTOS(vp);
 	struct snode *csp = VTOS(sp->s_commonvp);
 
-	if (STREAMSTAB(getmajor(sp->s_dev)))
+	if (vp->v_stream)
 		return ((offset_t)-1);
 	else if (csp->s_flag & SANYOFFSET)	/* D_U64BIT */
 		return ((offset_t)-1);
@@ -847,7 +845,7 @@ device_close(struct vnode *vp, int flag, struct cred *cr)
 	switch (type) {
 
 	case VCHR:
-		if (STREAMSTAB(getmajor(dev))) {
+		if (vp->v_stream) {
 			if (cvp->v_stream != NULL)
 				error = strclose(cvp, flag, cr);
 			vp->v_stream = NULL;
diff --git a/usr/src/uts/common/fs/specfs/specvnops.c b/usr/src/uts/common/fs/specfs/specvnops.c
index 94183f2f76..de3aae70fa 100644
--- a/usr/src/uts/common/fs/specfs/specvnops.c
+++ b/usr/src/uts/common/fs/specfs/specvnops.c
@@ -19,7 +19,7 @@
  * CDDL HEADER END
  */
 /*
- * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
@@ -637,10 +637,21 @@ spec_open(struct vnode **vpp, int flag, struct cred *cr, caller_context_t *cc)
 	    (devopsp[maj]->devo_cb_ops->cb_open == NULL))
 		return (ENXIO);
 
-	/* split streams .vs. non-streams */
-	if (STREAMSTAB(maj))
+	/*
+	 * split STREAMS vs. non-STREAMS
+	 *
+	 * If the device is a dual-personality device, then we might want
+	 * to allow for a regular OTYP_BLK open.  If however it's strictly
+	 * a pure STREAMS device, the cb_open entry point will be
+	 * nodev() which returns ENXIO.  This does make this failure path
+	 * somewhat longer, but such attempts to use OTYP_BLK with STREAMS
+	 * devices should be exceedingly rare.  (Most of the time they will
+	 * be due to programmer error.)
+	 */
+	if ((vp->v_type == VCHR) && (STREAMSTAB(maj)))
 		goto streams_open;
 
+not_streams:
 	/*
 	 * Wait for in progress last close to complete. This guarantees
 	 * to the driver writer that we will never be in the drivers
@@ -751,9 +762,6 @@ spec_open(struct vnode **vpp, int flag, struct cred *cr, caller_context_t *cc)
 	return (error);
 
 streams_open:
-	if (vp->v_type != VCHR)
-		return (ENXIO);
-
 	/*
 	 * Lock common snode to prevent any new clone opens on this
 	 * stream while one is in progress. This is necessary since
@@ -846,6 +854,14 @@ streams_open:
 		SN_RELE(csp);
 	}
 
+	/*
+	 * Resolution for STREAMS vs. regular character device: If the
+	 * STREAMS open(9e) returns ENOSTR, then try an ordinary device
+	 * open instead.
+	 */
+	if (error == ENOSTR) {
+		goto not_streams;
+	}
 	return (error);
 }
 
@@ -972,7 +988,7 @@ spec_read(
 
 	ASSERT(vp->v_type == VCHR || vp->v_type == VBLK);
 
-	if (STREAMSTAB(getmajor(dev))) {	/* stream */
+	if (vp->v_stream) {
 		ASSERT(vp->v_type == VCHR);
 		smark(sp, SACC);
 		return (strread(vp, uiop, cr));
@@ -994,7 +1010,7 @@ spec_read(
 
 	if (vp->v_type == VCHR) {
 		smark(sp, SACC);
-		ASSERT(STREAMSTAB(getmajor(dev)) == 0);
+		ASSERT(vp->v_stream == NULL);
 		return (cdev_read(dev, uiop, cr));
 	}
 
@@ -1078,7 +1094,7 @@ spec_write(
 
 	ASSERT(vp->v_type == VCHR || vp->v_type == VBLK);
 
-	if (STREAMSTAB(getmajor(dev))) {
+	if (vp->v_stream) {
 		ASSERT(vp->v_type == VCHR);
 		smark(sp, SUPD);
 		return (strwrite(vp, uiop, cr));
@@ -1097,7 +1113,7 @@ spec_write(
 
 	if (vp->v_type == VCHR) {
 		smark(sp, SUPD);
-		ASSERT(STREAMSTAB(getmajor(dev)) == 0);
+		ASSERT(vp->v_stream == NULL);
 		return (cdev_write(dev, uiop, cr));
 	}
 
@@ -1258,7 +1274,7 @@ spec_ioctl(struct vnode *vp, int cmd, intptr_t arg, int mode, struct cred *cr,
 
 	sp = VTOS(vp);
 	dev = sp->s_dev;
-	if (STREAMSTAB(getmajor(dev))) {
+	if (vp->v_stream) {
 		error = strioctl(vp, cmd, arg, mode, U_TO_K, cr, rvalp);
 	} else {
 		error = cdev_ioctl(dev, cmd, arg, mode, cr, rvalp);
@@ -2210,7 +2226,7 @@ spec_poll(
 	else {
 		ASSERT(vp->v_type == VCHR);
 		dev = vp->v_rdev;
-		if (STREAMSTAB(getmajor(dev))) {
+		if (vp->v_stream) {
 			ASSERT(vp->v_stream != NULL);
 			error = strpoll(vp->v_stream, events, anyyet,
 			    reventsp, phpp);
diff --git a/usr/src/uts/common/os/driver_lyr.c b/usr/src/uts/common/os/driver_lyr.c
index 525fd399cc..fafb02ad89 100644
--- a/usr/src/uts/common/os/driver_lyr.c
+++ b/usr/src/uts/common/os/driver_lyr.c
@@ -382,7 +382,7 @@ handle_alloc(vnode_t *vp, struct ldi_ident *ident)
 
 	/* set the device type for this handle */
 	lhp->lh_type = 0;
-	if (STREAMSTAB(getmajor(vp->v_rdev))) {
+	if (vp->v_stream) {
 		ASSERT(vp->v_type == VCHR);
 		lhp->lh_type |= LH_STREAM;
 	} else {
@@ -524,11 +524,6 @@ ldi_vp_from_dev(dev_t dev, int otyp, vnode_t **vpp)
 	if ((dip = e_ddi_hold_devi_by_dev(dev, 0)) == NULL)
 		return (ENODEV);
 
-	if (STREAMSTAB(getmajor(dev)) && (otyp != OTYP_CHR)) {
-		ddi_release_devi(dip);  /* from e_ddi_hold_devi_by_dev */
-		return (ENXIO);
-	}
-
 	vp = makespecvp(dev, OTYP_TO_VTYP(otyp));
 	spec_assoc_vp_with_devi(vp, dip);
 	ddi_release_devi(dip);  /* from e_ddi_hold_devi_by_dev */
@@ -3236,8 +3231,7 @@ ldi_ev_register_callbacks(ldi_handle_t lh, ldi_ev_cookie_t cookie,
 	 */
 	lecp->lec_lhp = lhp;
 	lecp->lec_dev = lhp->lh_vp->v_rdev;
-	lecp->lec_spec = (lhp->lh_vp->v_type == VCHR) ?
-	    S_IFCHR : S_IFBLK;
+	lecp->lec_spec = VTYP_TO_STYP(lhp->lh_vp->v_type);
 	lecp->lec_notify = callb->cb_notify;
 	lecp->lec_finalize = callb->cb_finalize;
 	lecp->lec_arg = arg;