Add micro "disk" layer which should enable us to pull all the slice/label

stuff out of the device drivers.

1 files changed, 183 insertions, 0 deletions

diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
new file mode 100644
index 0000000..42b1a3a
--- /dev/null
+++ b/sys/kern/subr_disk.c
@@ -0,0 +1,183 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * $FreeBSD$
+ *
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/buf.h>
+#include <sys/conf.h>
+#include <sys/disk.h>
+#include <sys/malloc.h>
+
+MALLOC_DEFINE(M_DISK, "disk", "disk data");
+
+static d_strategy_t diskstrategy;
+static d_open_t diskopen;
+static d_close_t diskclose; 
+static d_ioctl_t diskioctl;
+static d_psize_t diskpsize;
+ 
+static struct cdevsw disk_cdevsw = {
+	/* open */      diskopen,
+	/* close */     diskclose,
+	/* read */      physread,
+	/* write */     physwrite,
+	/* ioctl */     diskioctl,
+	/* stop */      nostop,
+	/* reset */     noreset,
+	/* devtotty */  nodevtotty,
+	/* poll */      nopoll,
+	/* mmap */      nommap,
+	/* strategy */  diskstrategy,
+	/* name */      "disk",
+	/* parms */     noparms,
+	/* maj */       -1,
+	/* dump */      nodump,
+	/* psize */     diskpsize,
+	/* flags */     D_DISK,
+	/* maxio */     0,
+	/* bmaj */      -1,
+};      
+
+dev_t
+disk_create(int unit, struct disk *dp, struct cdevsw *cdevsw)
+{
+	dev_t dev;
+	struct cdevsw *cds;
+
+	dp->d_devsw = cdevsw;
+	dev = makedev(cdevsw->d_maj, 0);	
+	cds = devsw(dev);
+	if (!cds) {
+		/* Build the "real" cdevsw */
+		MALLOC(cds, struct cdevsw *, sizeof(*cds), M_DISK, M_WAITOK);
+		*cds = disk_cdevsw;
+		cds->d_name = dp->d_devsw->d_name;
+		cds->d_maj = dp->d_devsw->d_maj;
+		cds->d_bmaj = dp->d_devsw->d_bmaj;
+		cds->d_flags = dp->d_devsw->d_flags;
+
+		cdevsw_add(cds);
+	}
+
+	printf("Creating DISK %s%d\n", cds->d_name, unit);
+	dev = make_dev(cds, dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART),
+	    0, 0, 0, "r%s%d", cds->d_name, unit);
+
+	dev->si_disk = dp;
+	dp->d_dev = dev;
+	return (dev);
+}
+
+void
+disk_delete(dev_t dev)
+{
+	return;
+}
+
+static int
+diskopen(dev_t dev, int oflags, int devtype, struct proc *p)
+{
+	dev_t pdev;
+	struct disk *dp;
+	int error;
+
+	pdev = dkmodpart(dkmodslice(dev, WHOLE_DISK_SLICE), RAW_PART);
+	dp = pdev->si_disk;
+	dev->si_disk = pdev->si_disk;
+	dev->si_drv1 = pdev->si_drv1;
+	dev->si_drv2 = pdev->si_drv2;
+	if (!dp)
+		return (ENXIO);
+	dev->si_disk = dp;
+	if (!dp->d_opencount++) {
+		error = dp->d_devsw->d_open(dev, oflags, devtype, p);
+		if (error)
+			return(error);
+	}
+
+	error = dsopen(dev, devtype, 0, &dp->d_slice, &dp->d_label);
+
+	if (error && !--dp->d_opencount)
+		dp->d_devsw->d_close(dev, oflags, devtype, p);
+	return(error);
+}
+
+static int
+diskclose(dev_t dev, int fflag, int devtype, struct proc *p)
+{
+	struct disk *dp;
+	int error;
+
+	error = 0;
+	dp = dev->si_disk;
+	dsclose(dev, devtype, dp->d_slice);
+	if (!--dp->d_opencount)
+		error = dp->d_devsw->d_close(dev, fflag, devtype, p);
+	return (error);
+}
+
+static void
+diskstrategy(struct buf *bp)
+{
+	dev_t pdev;
+	struct disk *dp;
+
+	dp = bp->b_dev->si_disk;
+	if (!dp) {
+		pdev = dkmodpart(dkmodslice(bp->b_dev, WHOLE_DISK_SLICE), RAW_PART);
+		dp = pdev->si_disk;
+		bp->b_dev->si_drv1 = pdev->si_drv1;
+		bp->b_dev->si_drv2 = pdev->si_drv2;
+		/* XXX: don't set bp->b_dev->si_disk (?) */
+	} else {
+		pdev = dp->d_dev;
+	}
+
+	if (!dp) {
+		bp->b_error = ENXIO;
+		bp->b_flags |= B_ERROR;
+		biodone(bp);
+		return;
+	}
+
+	if (dscheck(bp, dp->d_slice) < 0) {
+		biodone(bp);
+		return;
+	}
+
+	dp->d_devsw->d_strategy(bp);
+	return;
+	
+}
+
+static int
+diskioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct proc *p)
+{
+	struct disk *dp;
+	int error;
+
+	dp = dev->si_disk;
+	error = dsioctl(dev, cmd, data, fflag, &dp->d_slice);
+	if (error == ENOIOCTL)
+		error = dp->d_devsw->d_ioctl(dev, cmd, data, fflag, p);
+	return (error);
+}
+
+static int
+diskpsize(dev_t dev)
+{
+	struct disk *dp;
+
+	dp = dev->si_disk;
+	return (dssize(dev, &dp->d_slice));
+}