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, 18 insertions, 15 deletions

diff --git a/sys/dev/mlx/mlx_disk.c b/sys/dev/mlx/mlx_disk.c
index bd86466..2ad0bc6 100644
--- a/sys/dev/mlx/mlx_disk.c
+++ b/sys/dev/mlx/mlx_disk.c
@@ -219,30 +219,33 @@ mlxd_attach(device_t dev)
 		  sc->mlxd_drive->ms_size / ((1024 * 1024) / MLX_BLKSIZE),
 		  sc->mlxd_drive->ms_size, sc->mlxd_drive->ms_raidlevel, state);
 
-    sc->mlxd_disk.d_open = mlxd_open;
-    sc->mlxd_disk.d_close = mlxd_close;
-    sc->mlxd_disk.d_ioctl = mlxd_ioctl;
-    sc->mlxd_disk.d_strategy = mlxd_strategy;
-    sc->mlxd_disk.d_name = "mlxd";
-    sc->mlxd_disk.d_drv1 = sc;
-    sc->mlxd_disk.d_sectorsize = MLX_BLKSIZE;
-    sc->mlxd_disk.d_mediasize = MLX_BLKSIZE * (off_t)sc->mlxd_drive->ms_size;
-    sc->mlxd_disk.d_fwsectors = sc->mlxd_drive->ms_sectors;
-    sc->mlxd_disk.d_fwheads = sc->mlxd_drive->ms_heads;
+    sc->mlxd_disk = disk_alloc();
+    sc->mlxd_disk->d_open = mlxd_open;
+    sc->mlxd_disk->d_close = mlxd_close;
+    sc->mlxd_disk->d_ioctl = mlxd_ioctl;
+    sc->mlxd_disk->d_strategy = mlxd_strategy;
+    sc->mlxd_disk->d_name = "mlxd";
+    sc->mlxd_disk->d_unit = sc->mlxd_unit;
+    sc->mlxd_disk->d_drv1 = sc;
+    sc->mlxd_disk->d_sectorsize = MLX_BLKSIZE;
+    sc->mlxd_disk->d_mediasize = MLX_BLKSIZE * (off_t)sc->mlxd_drive->ms_size;
+    sc->mlxd_disk->d_fwsectors = sc->mlxd_drive->ms_sectors;
+    sc->mlxd_disk->d_fwheads = sc->mlxd_drive->ms_heads;
+    sc->mlxd_disk->d_flags = DISKFLAG_NEEDSGIANT;
 
     /* 
      * Set maximum I/O size to the lesser of the recommended maximum and the practical
      * maximum except on v2 cards where the maximum is set to 8 pages.
      */
     if (sc->mlxd_controller->mlx_iftype == MLX_IFTYPE_2)
-	sc->mlxd_disk.d_maxsize = 8 * PAGE_SIZE;
+	sc->mlxd_disk->d_maxsize = 8 * PAGE_SIZE;
     else {
 	s1 = sc->mlxd_controller->mlx_enq2->me_maxblk * MLX_BLKSIZE;
 	s2 = (sc->mlxd_controller->mlx_enq2->me_max_sg - 1) * PAGE_SIZE;
-	sc->mlxd_disk.d_maxsize = imin(s1, s2);
+	sc->mlxd_disk->d_maxsize = imin(s1, s2);
     }
 
-    disk_create(sc->mlxd_unit, &sc->mlxd_disk, 0, NULL, NULL);
+    disk_create(sc->mlxd_disk, DISK_VERSION);
 
     return (0);
 }
@@ -254,7 +257,7 @@ mlxd_detach(device_t dev)
 
     debug_called(1);
 
-    disk_destroy(&sc->mlxd_disk);
+    disk_destroy(sc->mlxd_disk);
 
     return(0);
 }
diff --git a/sys/dev/mlx/mlxvar.h b/sys/dev/mlx/mlxvar.h
index 43cbcb1..e499569 100644
--- a/sys/dev/mlx/mlxvar.h
+++ b/sys/dev/mlx/mlxvar.h
@@ -228,7 +228,7 @@ struct mlxd_softc
     device_t		mlxd_dev;
     struct mlx_softc	*mlxd_controller;
     struct mlx_sysdrive	*mlxd_drive;
-    struct disk		mlxd_disk;
+    struct disk		*mlxd_disk;
     int			mlxd_unit;
     int			mlxd_flags;
 #define MLXD_OPEN	(1<<0)		/* drive is open (can't shut down) */