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

3 files changed, 140 insertions, 24 deletions

diff --git a/sys/cam/ata/ata_da.c b/sys/cam/ata/ata_da.c
index 8e93302..f1a9433 100644
--- a/sys/cam/ata/ata_da.c
+++ b/sys/cam/ata/ata_da.c
@@ -812,6 +812,25 @@ adasysctlinit(void *context, int pending)
 	cam_periph_release(periph);
 }
 
+static int
+adagetattr(struct bio *bp)
+{
+	int ret = -1;
+	struct cam_periph *periph;
+
+	if (bp->bio_disk == NULL || bp->bio_disk->d_drv1)
+		return ENXIO;
+	periph = (struct cam_periph *)bp->bio_disk->d_drv1;
+	if (periph->path == NULL)
+		return ENXIO;
+
+	ret = xpt_getattr(bp->bio_data, bp->bio_length, bp->bio_attribute,
+	    periph->path);
+	if (ret == 0)
+		bp->bio_completed = bp->bio_length;
+	return ret;
+}
+
 static cam_status
 adaregister(struct cam_periph *periph, void *arg)
 {
@@ -917,6 +936,7 @@ adaregister(struct cam_periph *periph, void *arg)
 	softc->disk->d_open = adaopen;
 	softc->disk->d_close = adaclose;
 	softc->disk->d_strategy = adastrategy;
+	softc->disk->d_getattr = adagetattr;
 	softc->disk->d_dump = adadump;
 	softc->disk->d_name = "ada";
 	softc->disk->d_drv1 = periph;
@@ -938,8 +958,6 @@ adaregister(struct cam_periph *periph, void *arg)
 	    ((softc->flags & ADA_FLAG_CAN_CFA) &&
 	    !(softc->flags & ADA_FLAG_CAN_48BIT)))
 		softc->disk->d_flags |= DISKFLAG_CANDELETE;
-	strlcpy(softc->disk->d_ident, cgd->serial_num,
-	    MIN(sizeof(softc->disk->d_ident), cgd->serial_num_len + 1));
 	strlcpy(softc->disk->d_descr, cgd->ident_data.model,
 	    MIN(sizeof(softc->disk->d_descr), sizeof(cgd->ident_data.model)));
 	softc->disk->d_hba_vendor = cpi.hba_vendor;
diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index b6f7cf5..a436318 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -44,6 +44,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/eventhandler.h>
 #include <sys/malloc.h>
 #include <sys/cons.h>
+#include <geom/geom.h>
 #include <geom/geom_disk.h>
 #endif /* _KERNEL */
 
@@ -933,6 +934,25 @@ dadump(void *arg, void *virtual, vm_offset_t physical, off_t offset, size_t leng
 	return (0);
 }
 
+static int
+dagetattr(struct bio *bp)
+{
+	int ret = -1;
+	struct cam_periph *periph;
+
+	if (bp->bio_disk == NULL || bp->bio_disk->d_drv1 == NULL)
+		return ENXIO;
+	periph = (struct cam_periph *)bp->bio_disk->d_drv1;
+	if (periph->path == NULL)
+		return ENXIO;
+
+	ret = xpt_getattr(bp->bio_data, bp->bio_length, bp->bio_attribute,
+	    periph->path);
+	if (ret == 0)
+		bp->bio_completed = bp->bio_length;
+	return ret;
+}
+
 static void
 dainit(void)
 {
@@ -1046,6 +1066,20 @@ daasync(void *callback_arg, u_int32_t code,
 		 && status != CAM_REQ_INPROG)
 			printf("daasync: Unable to attach to new device "
 				"due to status 0x%x\n", status);
+		return;
+	}
+	case AC_ADVINFO_CHANGED:
+	{
+		uintptr_t buftype;
+
+		buftype = (uintptr_t)arg;
+		if (buftype == CDAI_TYPE_PHYS_PATH) {
+			struct da_softc *softc;
+
+			softc = periph->softc;
+			disk_attr_changed(softc->disk, "GEOM::physpath",
+					  M_NOWAIT);
+		}
 		break;
 	}
 	case AC_SENT_BDR:
@@ -1233,17 +1267,6 @@ daregister(struct cam_periph *periph, void *arg)
 	TASK_INIT(&softc->sysctl_task, 0, dasysctlinit, periph);
 
 	/*
-	 * Add async callbacks for bus reset and
-	 * bus device reset calls.  I don't bother
-	 * checking if this fails as, in most cases,
-	 * the system will function just fine without
-	 * them and the only alternative would be to
-	 * not attach the device on failure.
-	 */
-	xpt_register_async(AC_SENT_BDR | AC_BUS_RESET | AC_LOST_DEVICE,
-			   daasync, periph, periph->path);
-
-	/*
 	 * Take an exclusive refcount on the periph while dastart is called
 	 * to finish the probe.  The reference will be dropped in dadone at
 	 * the end of probe.
@@ -1303,6 +1326,7 @@ daregister(struct cam_periph *periph, void *arg)
 	softc->disk->d_close = daclose;
 	softc->disk->d_strategy = dastrategy;
 	softc->disk->d_dump = dadump;
+	softc->disk->d_getattr = dagetattr;
 	softc->disk->d_name = "da";
 	softc->disk->d_drv1 = periph;
 	if (cpi.maxio == 0)
@@ -1315,8 +1339,6 @@ daregister(struct cam_periph *periph, void *arg)
 	softc->disk->d_flags = 0;
 	if ((softc->quirks & DA_Q_NO_SYNC_CACHE) == 0)
 		softc->disk->d_flags |= DISKFLAG_CANFLUSHCACHE;
-	strlcpy(softc->disk->d_ident, cgd->serial_num,
-	    MIN(sizeof(softc->disk->d_ident), cgd->serial_num_len + 1));
 	cam_strvis(softc->disk->d_descr, cgd->inq_data.vendor,
 	    sizeof(cgd->inq_data.vendor), sizeof(softc->disk->d_descr));
 	strlcat(softc->disk->d_descr, " ", sizeof(softc->disk->d_descr));
@@ -1330,6 +1352,25 @@ daregister(struct cam_periph *periph, void *arg)
 	disk_create(softc->disk, DISK_VERSION);
 	mtx_lock(periph->sim->mtx);
 
+	/*
+	 * Add async callbacks for events of interest.
+	 * I don't bother checking if this fails as,
+	 * in most cases, the system will function just
+	 * fine without them and the only alternative
+	 * would be to not attach the device on failure.
+	 */
+	xpt_register_async(AC_SENT_BDR | AC_BUS_RESET
+			 | AC_LOST_DEVICE | AC_ADVINFO_CHANGED,
+			   daasync, periph, periph->path);
+
+	/*
+	 * Emit an attribute changed notification just in case 
+	 * physical path information arrived before our async
+	 * event handler was registered, but after anyone attaching
+	 * to our disk device polled it.
+	 */
+	disk_attr_changed(softc->disk, "GEOM::physpath", M_NOWAIT);
+
 	xpt_schedule(periph, CAM_PRIORITY_DEV);
 
 	return(CAM_REQ_CMP);
diff --git a/sys/cam/scsi/scsi_pass.c b/sys/cam/scsi/scsi_pass.c
index 5b24d82..a124468 100644
--- a/sys/cam/scsi/scsi_pass.c
+++ b/sys/cam/scsi/scsi_pass.c
@@ -39,6 +39,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/errno.h>
 #include <sys/devicestat.h>
 #include <sys/proc.h>
+#include <sys/taskqueue.h>
 
 #include <cam/cam.h>
 #include <cam/cam_ccb.h>
@@ -70,12 +71,14 @@ typedef enum {
 #define ccb_bp		ppriv_ptr1
 
 struct pass_softc {
-	pass_state		state;
-	pass_flags		flags;
-	u_int8_t		pd_type;
-	union ccb		saved_ccb;
-	struct devstat		*device_stats;
-	struct cdev *dev;
+	pass_state	 state;
+	pass_flags	 flags;
+	u_int8_t	 pd_type;
+	union ccb	 saved_ccb;
+	struct devstat	*device_stats;
+	struct cdev	*dev;
+	struct cdev	*alias_dev;
+	struct task	 add_physpath_task;
 };
 
 
@@ -88,6 +91,7 @@ static	periph_ctor_t	passregister;
 static	periph_oninv_t	passoninvalidate;
 static	periph_dtor_t	passcleanup;
 static	periph_start_t	passstart;
+static void		pass_add_physpath(void *context, int pending);
 static	void		passasync(void *callback_arg, u_int32_t code,
 				  struct cam_path *path, void *arg);
 static	void		passdone(struct cam_periph *periph, 
@@ -168,17 +172,45 @@ passcleanup(struct cam_periph *periph)
 	if (bootverbose)
 		xpt_print(periph->path, "removing device entry\n");
 	devstat_remove_entry(softc->device_stats);
+
 	cam_periph_unlock(periph);
+	taskqueue_drain(taskqueue_thread, &softc->add_physpath_task);
+
 	/*
 	 * passcleanup() is indirectly a d_close method via passclose,
 	 * so using destroy_dev(9) directly can result in deadlock.
 	 */
 	destroy_dev_sched(softc->dev);
 	cam_periph_lock(periph);
+
 	free(softc, M_DEVBUF);
 }
 
 static void
+pass_add_physpath(void *context, int pending)
+{
+	struct cam_periph *periph;
+	struct pass_softc *softc;
+	char *physpath;
+
+	/*
+	 * If we have one, create a devfs alias for our
+	 * physical path.
+	 */
+	periph = context;
+	softc = periph->softc;
+	physpath = malloc(MAXPATHLEN, M_DEVBUF, M_WAITOK);
+	if (xpt_getattr(physpath, MAXPATHLEN,
+			"GEOM::physpath", periph->path) == 0
+	 && strlen(physpath) != 0) {
+
+		make_dev_physpath_alias(MAKEDEV_WAITOK, &softc->alias_dev,
+					softc->dev, softc->alias_dev, physpath);
+	}
+	free(physpath, M_DEVBUF);
+}
+
+static void
 passasync(void *callback_arg, u_int32_t code,
 	  struct cam_path *path, void *arg)
 {
@@ -219,6 +251,20 @@ passasync(void *callback_arg, u_int32_t code,
 
 		break;
 	}
+	case AC_ADVINFO_CHANGED:
+	{
+		uintptr_t buftype;
+
+		buftype = (uintptr_t)arg;
+		if (buftype == CDAI_TYPE_PHYS_PATH) {
+			struct pass_softc *softc;
+
+			softc = (struct pass_softc *)periph->softc;
+			taskqueue_enqueue(taskqueue_thread,
+					  &softc->add_physpath_task);
+		}
+		break;
+	}
 	default:
 		cam_periph_async(periph, code, path, arg);
 		break;
@@ -292,11 +338,22 @@ passregister(struct cam_periph *periph, void *arg)
 	mtx_lock(periph->sim->mtx);
 	softc->dev->si_drv1 = periph;
 
+	TASK_INIT(&softc->add_physpath_task, /*priority*/0,
+		  pass_add_physpath, periph);
+
+	/*
+	 * See if physical path information is already available.
+	 */
+	taskqueue_enqueue(taskqueue_thread, &softc->add_physpath_task);
+
 	/*
-	 * Add an async callback so that we get
-	 * notified if this device goes away.
+	 * Add an async callback so that we get notified if
+	 * this device goes away or its physical path
+	 * (stored in the advanced info data of the EDT) has
+	 * changed.
 	 */
-	xpt_register_async(AC_LOST_DEVICE, passasync, periph, periph->path);
+	xpt_register_async(AC_LOST_DEVICE | AC_ADVINFO_CHANGED,
+			   passasync, periph, periph->path);
 
 	if (bootverbose)
 		xpt_announce_periph(periph, NULL);