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.

2 files changed, 17 insertions, 14 deletions

diff --git a/sys/dev/amr/amr_disk.c b/sys/dev/amr/amr_disk.c
index 42d09a2..a93e1ed 100644
--- a/sys/dev/amr/amr_disk.c
+++ b/sys/dev/amr/amr_disk.c
@@ -134,10 +134,10 @@ amrd_open(struct disk *dp)
     label->d_secpercyl  = sc->amrd_drive->al_sectors * sc->amrd_drive->al_heads;
     label->d_secperunit = sc->amrd_drive->al_size;
 #else
-    sc->amrd_disk.d_sectorsize = AMR_BLKSIZE;
-    sc->amrd_disk.d_mediasize = (off_t)sc->amrd_drive->al_size * AMR_BLKSIZE;
-    sc->amrd_disk.d_fwsectors = sc->amrd_drive->al_sectors;
-    sc->amrd_disk.d_fwheads = sc->amrd_drive->al_heads;
+    sc->amrd_disk->d_sectorsize = AMR_BLKSIZE;
+    sc->amrd_disk->d_mediasize = (off_t)sc->amrd_drive->al_size * AMR_BLKSIZE;
+    sc->amrd_disk->d_fwsectors = sc->amrd_drive->al_sectors;
+    sc->amrd_disk->d_fwheads = sc->amrd_drive->al_heads;
 #endif
 
     return (0);
@@ -247,13 +247,16 @@ amrd_attach(device_t dev)
 		  sc->amrd_drive->al_size, sc->amrd_drive->al_properties & AMR_DRV_RAID_MASK, 
 		  amr_describe_code(amr_table_drvstate, AMR_DRV_CURSTATE(sc->amrd_drive->al_state)));
 
-    sc->amrd_disk.d_drv1 = sc;
-    sc->amrd_disk.d_maxsize = (AMR_NSEG - 1) * PAGE_SIZE;
-    sc->amrd_disk.d_open = amrd_open;
-    sc->amrd_disk.d_strategy = amrd_strategy;
-    sc->amrd_disk.d_name = "amrd";
-    sc->amrd_disk.d_dump = (dumper_t *)amrd_dump;
-    disk_create(sc->amrd_unit, &sc->amrd_disk, 0, NULL, NULL);
+    sc->amrd_disk = disk_alloc();
+    sc->amrd_disk->d_drv1 = sc;
+    sc->amrd_disk->d_maxsize = (AMR_NSEG - 1) * PAGE_SIZE;
+    sc->amrd_disk->d_open = amrd_open;
+    sc->amrd_disk->d_strategy = amrd_strategy;
+    sc->amrd_disk->d_name = "amrd";
+    sc->amrd_disk->d_dump = (dumper_t *)amrd_dump;
+    sc->amrd_disk->d_unit = sc->amrd_unit;
+    sc->amrd_disk->d_flags = DISKFLAG_NEEDSGIANT;
+    disk_create(sc->amrd_disk, DISK_VERSION);
 #ifdef FREEBSD_4
     disks_registered++;
 #endif
@@ -268,14 +271,14 @@ amrd_detach(device_t dev)
 
     debug_called(1);
 
-    if (sc->amrd_disk.d_flags & DISKFLAG_OPEN)
+    if (sc->amrd_disk->d_flags & DISKFLAG_OPEN)
 	return(EBUSY);
 
 #ifdef FREEBSD_4
     if (--disks_registered == 0)
 	cdevsw_remove(&amrddisk_cdevsw);
 #else
-    disk_destroy(&sc->amrd_disk);
+    disk_destroy(sc->amrd_disk);
 #endif
     return(0);
 }
diff --git a/sys/dev/amr/amrvar.h b/sys/dev/amr/amrvar.h
index 1191954..2378c97 100644
--- a/sys/dev/amr/amrvar.h
+++ b/sys/dev/amr/amrvar.h
@@ -253,7 +253,7 @@ struct amrd_softc
     device_t		amrd_dev;
     struct amr_softc	*amrd_controller;
     struct amr_logdrive	*amrd_drive;
-    struct disk		amrd_disk;
+    struct disk		*amrd_disk;
     int			amrd_unit;
 };