[PATCH] dm store geometry
Allow drive geometry to be stored with a new DM_DEV_SET_GEOMETRY ioctl.
Device-mapper will now respond to HDIO_GETGEO. If the geometry information is
not available, zero will be returned for all of the parameters.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 65826bd..8edd643 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -15,6 +15,7 @@
#include <linux/slab.h>
#include <linux/devfs_fs_kernel.h>
#include <linux/dm-ioctl.h>
+#include <linux/hdreg.h>
#include <asm/uaccess.h>
@@ -700,6 +701,54 @@
return dm_hash_rename(param->name, new_name);
}
+static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
+{
+ int r = -EINVAL, x;
+ struct mapped_device *md;
+ struct hd_geometry geometry;
+ unsigned long indata[4];
+ char *geostr = (char *) param + param->data_start;
+
+ md = find_device(param);
+ if (!md)
+ return -ENXIO;
+
+ if (geostr < (char *) (param + 1) ||
+ invalid_str(geostr, (void *) param + param_size)) {
+ DMWARN("Invalid geometry supplied.");
+ goto out;
+ }
+
+ x = sscanf(geostr, "%lu %lu %lu %lu", indata,
+ indata + 1, indata + 2, indata + 3);
+
+ if (x != 4) {
+ DMWARN("Unable to interpret geometry settings.");
+ goto out;
+ }
+
+ if (indata[0] > 65535 || indata[1] > 255 ||
+ indata[2] > 255 || indata[3] > ULONG_MAX) {
+ DMWARN("Geometry exceeds range limits.");
+ goto out;
+ }
+
+ geometry.cylinders = indata[0];
+ geometry.heads = indata[1];
+ geometry.sectors = indata[2];
+ geometry.start = indata[3];
+
+ r = dm_set_geometry(md, &geometry);
+ if (!r)
+ r = __dev_status(md, param);
+
+ param->data_size = 0;
+
+out:
+ dm_put(md);
+ return r;
+}
+
static int do_suspend(struct dm_ioctl *param)
{
int r = 0;
@@ -1234,7 +1283,8 @@
{DM_LIST_VERSIONS_CMD, list_versions},
- {DM_TARGET_MSG_CMD, target_message}
+ {DM_TARGET_MSG_CMD, target_message},
+ {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
};
return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index b99df48..973e63d 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -17,6 +17,7 @@
#include <linux/mempool.h>
#include <linux/slab.h>
#include <linux/idr.h>
+#include <linux/hdreg.h>
#include <linux/blktrace_api.h>
static const char *_name = DM_NAME;
@@ -102,6 +103,9 @@
*/
struct super_block *frozen_sb;
struct block_device *suspended_bdev;
+
+ /* forced geometry settings */
+ struct hd_geometry geometry;
};
#define MIN_IOS 256
@@ -227,6 +231,13 @@
return 0;
}
+static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
+{
+ struct mapped_device *md = bdev->bd_disk->private_data;
+
+ return dm_get_geometry(md, geo);
+}
+
static inline struct dm_io *alloc_io(struct mapped_device *md)
{
return mempool_alloc(md->io_pool, GFP_NOIO);
@@ -313,6 +324,33 @@
return t;
}
+/*
+ * Get the geometry associated with a dm device
+ */
+int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo)
+{
+ *geo = md->geometry;
+
+ return 0;
+}
+
+/*
+ * Set the geometry of a device.
+ */
+int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
+{
+ sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
+
+ if (geo->start > sz) {
+ DMWARN("Start sector is beyond the geometry limits.");
+ return -EINVAL;
+ }
+
+ md->geometry = *geo;
+
+ return 0;
+}
+
/*-----------------------------------------------------------------
* CRUD START:
* A more elegant soln is in the works that uses the queue
@@ -906,6 +944,13 @@
sector_t size;
size = dm_table_get_size(t);
+
+ /*
+ * Wipe any geometry if the size of the table changed.
+ */
+ if (size != get_capacity(md->disk))
+ memset(&md->geometry, 0, sizeof(md->geometry));
+
__set_size(md, size);
if (size == 0)
return 0;
@@ -1261,6 +1306,7 @@
static struct block_device_operations dm_blk_dops = {
.open = dm_blk_open,
.release = dm_blk_close,
+ .getgeo = dm_blk_getgeo,
.owner = THIS_MODULE
};
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 79e8000..fd90bc8 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -14,6 +14,7 @@
#include <linux/device-mapper.h>
#include <linux/list.h>
#include <linux/blkdev.h>
+#include <linux/hdreg.h>
#define DM_NAME "device-mapper"
#define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
@@ -85,6 +86,12 @@
struct gendisk *dm_disk(struct mapped_device *md);
int dm_suspended(struct mapped_device *md);
+/*
+ * Geometry functions.
+ */
+int dm_get_geometry(struct mapped_device *md, struct hd_geometry *geo);
+int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo);
+
/*-----------------------------------------------------------------
* Functions for manipulating a table. Tables are also reference
* counted.