Change the disk(9) API in order to make device removal more robust.

Previously the "struct disk" were owned by the device driver and this
gave us problems when the device disappared and the users of that device
were not immediately disappearing.

Now the struct disk is allocate with a new call, disk_alloc() and owned
by geom_disk and just abandonned by the device driver when disk_create()
is called.

Unfortunately, this results in a ton of "s/\./->/" changes to device
drivers.

Since I'm doing the sweep anyway, a couple of other API improvements
have been carried out at the same time:

The Giant awareness flag has been flipped from DISKFLAG_NOGIANT to
DISKFLAG_NEEDSGIANT

A version number have been added to disk_create() so that we can detect,
report and ignore binary drivers with old ABI in the future.

Manual page update to follow shortly.

3 files changed, 17 insertions, 15 deletions

diff --git a/sys/dev/aac/aac.c b/sys/dev/aac/aac.c
index 2fec4cf846ec..57017bbc2cd5 100644
--- a/sys/dev/aac/aac.c
+++ b/sys/dev/aac/aac.c
@@ -2875,7 +2875,7 @@ aac_query_disk(struct aac_softc *sc, caddr_t uptr)
 		query_disk.Lun = 0;
 		query_disk.UnMapped = 0;
 		sprintf(&query_disk.diskDeviceName[0], "%s%d",
-		        disk->ad_disk.d_name, disk->ad_disk.d_unit);
+		        disk->ad_disk->d_name, disk->ad_disk->d_unit);
 	}
 	AAC_LOCK_RELEASE(&sc->aac_container_lock);
 
diff --git a/sys/dev/aac/aac_disk.c b/sys/dev/aac/aac_disk.c
index 382b64494861..2231a0e0d7c6 100644
--- a/sys/dev/aac/aac_disk.c
+++ b/sys/dev/aac/aac_disk.c
@@ -357,18 +357,20 @@ aac_disk_attach(device_t dev)
 
 	/* attach a generic disk device to ourselves */
 	sc->unit = device_get_unit(dev);
-	sc->ad_disk.d_drv1 = sc;
-	sc->ad_disk.d_name = "aacd";
-	sc->ad_disk.d_maxsize = aac_iosize_max;
-	sc->ad_disk.d_open = aac_disk_open;
-	sc->ad_disk.d_close = aac_disk_close;
-	sc->ad_disk.d_strategy = aac_disk_strategy;
-	sc->ad_disk.d_dump = aac_disk_dump;
-	sc->ad_disk.d_sectorsize = AAC_BLOCK_SIZE;
-	sc->ad_disk.d_mediasize = (off_t)sc->ad_size * AAC_BLOCK_SIZE;
-	sc->ad_disk.d_fwsectors = sc->ad_sectors;
-	sc->ad_disk.d_fwheads = sc->ad_heads;
-	disk_create(sc->unit, &sc->ad_disk, DISKFLAG_NOGIANT, NULL, NULL);
+	sc->ad_disk = disk_alloc();
+	sc->ad_disk->d_drv1 = sc;
+	sc->ad_disk->d_name = "aacd";
+	sc->ad_disk->d_maxsize = aac_iosize_max;
+	sc->ad_disk->d_open = aac_disk_open;
+	sc->ad_disk->d_close = aac_disk_close;
+	sc->ad_disk->d_strategy = aac_disk_strategy;
+	sc->ad_disk->d_dump = aac_disk_dump;
+	sc->ad_disk->d_sectorsize = AAC_BLOCK_SIZE;
+	sc->ad_disk->d_mediasize = (off_t)sc->ad_size * AAC_BLOCK_SIZE;
+	sc->ad_disk->d_fwsectors = sc->ad_sectors;
+	sc->ad_disk->d_fwheads = sc->ad_heads;
+	sc->ad_disk->d_unit = sc->unit;
+	disk_create(sc->ad_disk, DISK_VERSION);
 
 	return (0);
 }
@@ -388,7 +390,7 @@ aac_disk_detach(device_t dev)
 	if (sc->ad_flags & AAC_DISK_OPEN)
 		return(EBUSY);
 
-	disk_destroy(&sc->ad_disk);
+	disk_destroy(sc->ad_disk);
 
 	return(0);
 }
diff --git a/sys/dev/aac/aacvar.h b/sys/dev/aac/aacvar.h
index f2ee0f3b1b44..a4b30c396746 100644
--- a/sys/dev/aac/aacvar.h
+++ b/sys/dev/aac/aacvar.h
@@ -125,7 +125,7 @@ struct aac_disk
 	device_t			ad_dev;
 	struct aac_softc		*ad_controller;
 	struct aac_container		*ad_container;
-	struct disk			ad_disk;
+	struct disk			*ad_disk;
 	int				ad_flags;
 #define AAC_DISK_OPEN	(1<<0)
 	int				ad_cylinders;