Plumb device physical path reporting from CAM devices, through GEOM and

DEVFS, and make it accessible via the diskinfo utility.

Extend GEOM's generic attribute query mechanism into generic disk consumers.
sys/geom/geom_disk.c:
sys/geom/geom_disk.h:
sys/cam/scsi/scsi_da.c:
sys/cam/ata/ata_da.c:
	- Allow disk providers to implement a new method which can override
	  the default BIO_GETATTR response, d_getattr(struct bio *).  This
	  function returns -1 if not handled, otherwise it returns 0 or an
	  errno to be passed to g_io_deliver().

sys/cam/scsi/scsi_da.c:
sys/cam/ata/ata_da.c:
	- Don't copy the serial number to dp->d_ident anymore, as the CAM XPT
	  is now responsible for returning this information via
	  d_getattr()->(a)dagetattr()->xpt_getatr().

sys/geom/geom_dev.c:
	- Implement a new ioctl, DIOCGPHYSPATH, which returns the GEOM
	  attribute "GEOM::physpath", if possible.  If the attribute request
	  returns a zero-length string, ENOENT is returned.

usr.sbin/diskinfo/diskinfo.c:
	- If the DIOCGPHYSPATH ioctl is successful, report physical path
	  data when diskinfo is executed with the '-v' option.

Submitted by:	will
Reviewed by:	gibbs
Sponsored by:	Spectra Logic Corporation

Add generic attribute change notification support to GEOM.

sys/sys/geom/geom.h:
	Add a new attrchanged method field to both g_class
	and g_geom.

sys/sys/geom/geom.h:
sys/geom/geom_event.c:
	- Provide the g_attr_changed() function that providers
	  can use to advertise attribute changes.
	- Perform delivery of attribute change notifications
	  from a thread context via the standard GEOM event
	  mechanism.

sys/geom/geom_subr.c:
	Inherit the attrchanged method from class to geom (class instance).

sys/geom/geom_disk.c:
	Provide disk_attr_changed() to provide g_attr_changed() access
	to consumers of the disk API.

sys/cam/scsi/scsi_pass.c:
sys/cam/scsi/scsi_da.c:
sys/geom/geom_dev.c:
sys/geom/geom_disk.c:
	Use attribute changed events to track updates to physical path
	information.

sys/cam/scsi/scsi_da.c:
	Add AC_ADVINFO_CHANGED to the registered asynchronous CAM
	events for this driver.  When this event occurs, and
	the updated buffer type references our physical path
	attribute, emit a GEOM attribute changed event via the
	disk_attr_changed() API.

sys/cam/scsi/scsi_pass.c:
	Add AC_ADVINFO_CHANGED to the registered asynchronous CAM
	events for this driver.  When this event occurs, update
	the physical patch devfs alias for this pass instance.

Submitted by:	gibbs
Sponsored by:	Spectra Logic Corporation

6 files changed, 128 insertions, 1 deletions

diff --git a/sys/geom/geom.h b/sys/geom/geom.h
index 1dc6eb1..6256572 100644
--- a/sys/geom/geom.h
+++ b/sys/geom/geom.h
@@ -76,6 +76,7 @@ typedef void g_orphan_t (struct g_consumer *);
 
 typedef void g_start_t (struct bio *);
 typedef void g_spoiled_t (struct g_consumer *);
+typedef void g_attrchanged_t (struct g_consumer *, const char *attr);
 typedef void g_dumpconf_t (struct sbuf *, const char *indent, struct g_geom *,
     struct g_consumer *, struct g_provider *);
 
@@ -100,6 +101,7 @@ struct g_class {
 	 */
 	g_start_t		*start;
 	g_spoiled_t		*spoiled;
+	g_attrchanged_t		*attrchanged;
 	g_dumpconf_t		*dumpconf;
 	g_access_t		*access;
 	g_orphan_t		*orphan;
@@ -128,6 +130,7 @@ struct g_geom {
 	int			rank;
 	g_start_t		*start;
 	g_spoiled_t		*spoiled;
+	g_attrchanged_t		*attrchanged;
 	g_dumpconf_t		*dumpconf;
 	g_access_t		*access;
 	g_orphan_t		*orphan;
@@ -217,6 +220,7 @@ struct g_classifier_hook {
 /* geom_dev.c */
 struct cdev;
 void g_dev_print(void);
+void g_dev_physpath_changed(void);
 struct g_provider *g_dev_getprovider(struct cdev *dev);
 
 /* geom_dump.c */
@@ -232,6 +236,7 @@ typedef void g_event_t(void *, int flag);
 int g_post_event(g_event_t *func, void *arg, int flag, ...);
 int g_waitfor_event(g_event_t *func, void *arg, int flag, ...);
 void g_cancel_event(void *ref);
+int g_attr_changed(struct g_provider *pp, const char *attr, int flag);
 void g_orphan_provider(struct g_provider *pp, int error);
 void g_waitidlelock(void);
 
diff --git a/sys/geom/geom_dev.c b/sys/geom/geom_dev.c
index f291b32..210f2ee 100644
--- a/sys/geom/geom_dev.c
+++ b/sys/geom/geom_dev.c
@@ -41,6 +41,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/malloc.h>
 #include <sys/kernel.h>
 #include <sys/conf.h>
+#include <sys/ctype.h>
 #include <sys/bio.h>
 #include <sys/lock.h>
 #include <sys/mutex.h>
@@ -52,6 +53,12 @@ __FBSDID("$FreeBSD$");
 #include <sys/limits.h>
 #include <geom/geom.h>
 #include <geom/geom_int.h>
+#include <machine/stdarg.h>
+
+/*
+ * Use the consumer private field to reference a physdev alias (if any).
+ */
+#define cp_alias_dev	private
 
 static d_open_t		g_dev_open;
 static d_close_t	g_dev_close;
@@ -72,12 +79,14 @@ static struct cdevsw g_dev_cdevsw = {
 
 static g_taste_t g_dev_taste;
 static g_orphan_t g_dev_orphan;
+static g_attrchanged_t g_dev_attrchanged;
 
 static struct g_class g_dev_class	= {
 	.name = "DEV",
 	.version = G_VERSION,
 	.taste = g_dev_taste,
 	.orphan = g_dev_orphan,
+	.attrchanged = g_dev_attrchanged
 };
 
 void
@@ -93,6 +102,40 @@ g_dev_print(void)
 	printf("\n");
 }
 
+static void
+g_dev_attrchanged(struct g_consumer *cp, const char *attr)
+{
+
+	if (strcmp(attr, "GEOM::physpath") != 0)
+		return;
+
+	if (g_access(cp, 1, 0, 0) == 0) {
+		char *physpath;
+		int error, physpath_len;
+
+		physpath_len = MAXPATHLEN;
+		physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
+		error =
+		    g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
+		g_access(cp, -1, 0, 0);
+		if (error == 0 && strlen(physpath) != 0) {
+			struct cdev *dev;
+			struct cdev *old_alias_dev;
+			struct cdev **alias_devp;
+
+			dev = cp->geom->softc;
+			old_alias_dev = cp->cp_alias_dev;
+			alias_devp = (struct cdev **)&cp->cp_alias_dev;
+			make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
+			    dev, old_alias_dev, physpath);
+		} else if (cp->cp_alias_dev) {
+			destroy_dev((struct cdev *)cp->cp_alias_dev);
+			cp->cp_alias_dev = NULL;
+		}
+		g_free(physpath);
+	}
+}
+
 struct g_provider *
 g_dev_getprovider(struct cdev *dev)
 {
@@ -107,7 +150,6 @@ g_dev_getprovider(struct cdev *dev)
 	return (cp->provider);
 }
 
-
 static struct g_geom *
 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
 {
@@ -167,6 +209,9 @@ g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
 		adev->si_drv1 = gp;
 		adev->si_drv2 = cp;
 	}
+
+	g_dev_attrchanged(cp, "GEOM::physpath");
+
 	return (gp);
 }
 
@@ -365,6 +410,11 @@ g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread
 	case DIOCGSTRIPEOFFSET:
 		*(off_t *)data = cp->provider->stripeoffset;
 		break;
+	case DIOCGPHYSPATH:
+		error = g_io_getattr("GEOM::physpath", cp, &i, data);
+		if (error == 0 && *(char *)data == '\0')
+			error = ENOENT;
+		break;
 	default:
 		if (cp->provider->geom->ioctl != NULL) {
 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
diff --git a/sys/geom/geom_disk.c b/sys/geom/geom_disk.c
index e663e3d..17cae68 100644
--- a/sys/geom/geom_disk.c
+++ b/sys/geom/geom_disk.c
@@ -347,6 +347,15 @@ g_disk_start(struct bio *bp)
 		} while (bp2 != NULL);
 		break;
 	case BIO_GETATTR:
+		/* Give the driver a chance to override */
+		if (dp->d_getattr != NULL) {
+			if (bp->bio_disk == NULL)
+				bp->bio_disk = dp;
+			error = dp->d_getattr(bp);
+			if (error != -1)
+				break;
+			error = EJUSTRETURN;
+		}
 		if (g_handleattr_int(bp, "GEOM::candelete",
 		    (dp->d_flags & DISKFLAG_CANDELETE) != 0))
 			break;
@@ -582,6 +591,18 @@ disk_gone(struct disk *dp)
 			g_wither_provider(pp, ENXIO);
 }
 
+void
+disk_attr_changed(struct disk *dp, const char *attr, int flag)
+{
+	struct g_geom *gp;
+	struct g_provider *pp;
+
+	gp = dp->d_geom;
+	if (gp != NULL)
+		LIST_FOREACH(pp, &gp->provider, provider)
+			(void)g_attr_changed(pp, attr, flag);
+}
+
 static void
 g_kern_disks(void *p, int flag __unused)
 {
diff --git a/sys/geom/geom_disk.h b/sys/geom/geom_disk.h
index 2d5f15d..e92f4aa 100644
--- a/sys/geom/geom_disk.h
+++ b/sys/geom/geom_disk.h
@@ -49,6 +49,7 @@ struct disk;
 typedef	int	disk_open_t(struct disk *);
 typedef	int	disk_close_t(struct disk *);
 typedef	void	disk_strategy_t(struct bio *bp);
+typedef	int	disk_getattr_t(struct bio *bp);
 typedef	int	disk_ioctl_t(struct disk *, u_long cmd, void *data,
 			int fflag, struct thread *td);
 		/* NB: disk_ioctl_t SHALL be cast'able to d_ioctl_t */
@@ -75,6 +76,7 @@ struct disk {
 	disk_strategy_t		*d_strategy;
 	disk_ioctl_t		*d_ioctl;
 	dumper_t		*d_dump;
+	disk_getattr_t		*d_getattr;
 
 	/* Info fields from driver to geom_disk.c. Valid when open */
 	u_int			d_sectorsize;
@@ -104,6 +106,7 @@ struct disk *disk_alloc(void);
 void disk_create(struct disk *disk, int version);
 void disk_destroy(struct disk *disk);
 void disk_gone(struct disk *disk);
+void disk_attr_changed(struct disk *dp, const char *attr, int flag);
 
 #define DISK_VERSION_00		0x58561059
 #define DISK_VERSION_01		0x5856105a
diff --git a/sys/geom/geom_event.c b/sys/geom/geom_event.c
index d6e5498..1e2fc8d 100644
--- a/sys/geom/geom_event.c
+++ b/sys/geom/geom_event.c
@@ -110,6 +110,53 @@ g_waitidlelock(void)
 }
 #endif
 
+struct g_attrchanged_args {
+	struct g_provider *pp;
+	const char *attr;
+};
+
+static void
+g_attr_changed_event(void *arg, int flag)
+{
+	struct g_attrchanged_args *args;
+	struct g_provider *pp;
+	struct g_consumer *cp;
+	struct g_consumer *next_cp;
+
+	args = arg;
+	pp = args->pp;
+
+	g_topology_assert();
+	if (flag != EV_CANCEL && g_shutdown == 0) {
+
+		/*
+		 * Tell all consumers of the change.
+		 */
+		LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
+			if (cp->geom->attrchanged != NULL)
+				cp->geom->attrchanged(cp, args->attr);
+		}
+	}
+	g_free(args);
+}
+
+int
+g_attr_changed(struct g_provider *pp, const char *attr, int flag)
+{
+	struct g_attrchanged_args *args;
+	int error;
+
+	args = g_malloc(sizeof *args, flag);
+	if (args == NULL)
+		return (ENOMEM);
+	args->pp = pp;
+	args->attr = attr;
+	error = g_post_event(g_attr_changed_event, args, flag, pp, NULL);
+	if (error != 0)
+		g_free(args);
+	return (error);
+}
+
 void
 g_orphan_provider(struct g_provider *pp, int error)
 {
diff --git a/sys/geom/geom_subr.c b/sys/geom/geom_subr.c
index a0958f3..6e2589b 100644
--- a/sys/geom/geom_subr.c
+++ b/sys/geom/geom_subr.c
@@ -350,6 +350,7 @@ g_new_geomf(struct g_class *mp, const char *fmt, ...)
 	/* Fill in defaults from class */
 	gp->start = mp->start;
 	gp->spoiled = mp->spoiled;
+	gp->attrchanged = mp->attrchanged;
 	gp->dumpconf = mp->dumpconf;
 	gp->access = mp->access;
 	gp->orphan = mp->orphan;