dev/dm/device-mapper.c

/*        $NetBSD: device-mapper.c,v 1.6.2.3 2009/06/20 07:20:20 yamt Exp $ */

/*
 * Copyright (c) 2008 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Adam Hamsik.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * I want to say thank you to all people who helped me with this project.
 */

#include <sys/types.h>
#include <sys/param.h>

#include <sys/buf.h>
#include <sys/conf.h>
#include <sys/dkio.h>
#include <sys/disk.h>
#include <sys/disklabel.h>
#include <sys/ioctl.h>
#include <sys/ioccom.h>
#include <sys/kmem.h>
#include <sys/module.h>

#include "netbsd-dm.h"
#include "dm.h"

static dev_type_open(dmopen);
static dev_type_close(dmclose);
static dev_type_read(dmread);
static dev_type_write(dmwrite);
static dev_type_ioctl(dmioctl);
static dev_type_strategy(dmstrategy);
static dev_type_size(dmsize);

/* attach and detach routines */
int dmattach(void);
int dmdestroy(void);

static int dm_cmd_to_fun(prop_dictionary_t);
static int disk_ioctl_switch(dev_t, u_long, void *);
static int dm_ioctl_switch(u_long);
static void dmminphys(struct buf *);

/* ***Variable-definitions*** */
const struct bdevsw dm_bdevsw = {
	.d_open = dmopen,
	.d_close = dmclose,
	.d_strategy = dmstrategy,
	.d_ioctl = dmioctl,
	.d_dump = nodump,
	.d_psize = dmsize,
	.d_flag = D_DISK | D_MPSAFE
};

const struct cdevsw dm_cdevsw = {
	.d_open = dmopen,
	.d_close = dmclose,
	.d_read = dmread,
	.d_write = dmwrite,
	.d_ioctl = dmioctl,
	.d_stop = nostop,
	.d_tty = notty,
	.d_poll = nopoll,
	.d_mmap = nommap,
	.d_kqfilter = nokqfilter,
	.d_flag = D_DISK | D_MPSAFE
};

const struct dkdriver dmdkdriver = {
	.d_strategy = dmstrategy
};

extern uint64_t dev_counter;

/*
 * This array is used to translate cmd to function pointer.
 *
 * Interface between libdevmapper and lvm2tools uses different
 * names for one IOCTL call because libdevmapper do another thing
 * then. When I run "info" or "mknodes" libdevmapper will send same
 * ioctl to kernel but will do another things in userspace.
 *
 */
struct cmd_function cmd_fn[] = {
		{ .cmd = "version", .fn = dm_get_version_ioctl},
		{ .cmd = "targets", .fn = dm_list_versions_ioctl},
		{ .cmd = "create",  .fn = dm_dev_create_ioctl},
		{ .cmd = "info",    .fn = dm_dev_status_ioctl},
		{ .cmd = "mknodes", .fn = dm_dev_status_ioctl},
		{ .cmd = "names",   .fn = dm_dev_list_ioctl},
		{ .cmd = "suspend", .fn = dm_dev_suspend_ioctl},
		{ .cmd = "remove",  .fn = dm_dev_remove_ioctl},
		{ .cmd = "rename",  .fn = dm_dev_rename_ioctl},
		{ .cmd = "resume",  .fn = dm_dev_resume_ioctl},
		{ .cmd = "clear",   .fn = dm_table_clear_ioctl},
		{ .cmd = "deps",    .fn = dm_table_deps_ioctl},
		{ .cmd = "reload",  .fn = dm_table_load_ioctl},
		{ .cmd = "status",  .fn = dm_table_status_ioctl},
		{ .cmd = "table",   .fn = dm_table_status_ioctl},
		{NULL, NULL}
};


MODULE(MODULE_CLASS_DRIVER, dm, NULL);

/* New module handle routine */
static int
dm_modcmd(modcmd_t cmd, void *arg)
{
#ifdef _MODULE
	int bmajor = -1, cmajor = -1;

	switch (cmd) {
	case MODULE_CMD_INIT:
		dmattach();
		return devsw_attach("dm", &dm_bdevsw, &bmajor,
		    &dm_cdevsw, &cmajor);
		break;

	case MODULE_CMD_FINI:
		/*
		 * Disable unloading of dm module if there are any devices
		 * defined in driver. This is probably too strong we need
		 * to disable auto-unload only if there is mounted dm device
		 * present.
		 */
		if (dev_counter > 0)
			return EBUSY;
		dmdestroy();
		return devsw_detach(&dm_bdevsw, &dm_cdevsw);
		break;
	case MODULE_CMD_STAT:
		return ENOTTY;

	default:
		return ENOTTY;
	}

	return 0;
#else

	if (cmd == MODULE_CMD_INIT)
		return 0;
	return ENOTTY;

#endif /* _MODULE */
}


/* attach routine */
int
dmattach(void)
{
	dm_target_init();
	dm_dev_init();
	dm_pdev_init();

	return 0;
}

/* Destroy routine */
int
dmdestroy(void)
{
	dm_dev_destroy();
	dm_pdev_destroy();
	dm_target_destroy();

	return 0;
}

static int
dmopen(dev_t dev, int flags, int mode, struct lwp *l)
{
	aprint_debug("open routine called %" PRIu32 "\n", minor(dev));
	return 0;
}

static int
dmclose(dev_t dev, int flags, int mode, struct lwp *l)
{
	aprint_debug("CLOSE routine called\n");

	return 0;
}


static int
dmioctl(dev_t dev, const u_long cmd, void *data, int flag, struct lwp *l)
{
	int r;
	prop_dictionary_t dm_dict_in;

	r = 0;

	aprint_debug("dmioctl called\n");

	KASSERT(data != NULL);

	if (disk_ioctl_switch(dev, cmd, data) != 0) {
		struct plistref *pref = (struct plistref *) data;

		if((r = prop_dictionary_copyin_ioctl(pref, cmd, &dm_dict_in)) != 0)
			return r;

		dm_check_version(dm_dict_in);

		/* call cmd selected function */
		if ((r = dm_ioctl_switch(cmd)) != 0) {
			prop_object_release(dm_dict_in);
			return r;
		}

		/* run ioctl routine */
		if ((r = dm_cmd_to_fun(dm_dict_in)) != 0) {
			prop_object_release(dm_dict_in);
			return r;
		}

		r = prop_dictionary_copyout_ioctl(pref, cmd, dm_dict_in);

		prop_object_release(dm_dict_in);
	}

	return r;
}

/*
 * Translate command sent from libdevmapper to func.
 */
static int
dm_cmd_to_fun(prop_dictionary_t dm_dict){
	int i, r;
	prop_string_t command;

	r = 0;

	if ((command = prop_dictionary_get(dm_dict, DM_IOCTL_COMMAND)) == NULL)
		return EINVAL;

	for(i = 0; cmd_fn[i].cmd != NULL; i++)
		if (prop_string_equals_cstring(command, cmd_fn[i].cmd))
			break;

	if (cmd_fn[i].cmd == NULL)
		return EINVAL;

	aprint_debug("ioctl %s called\n", cmd_fn[i].cmd);
	r = cmd_fn[i].fn(dm_dict);

	return r;
}

/* Call apropriate ioctl handler function. */
static int
dm_ioctl_switch(u_long cmd)
{
	int r;

	r = 0;

	switch(cmd) {

	case NETBSD_DM_IOCTL:
		aprint_debug("NetBSD_DM_IOCTL called\n");
		break;

	default:
		 aprint_debug("unknown ioctl called\n");
		 return ENOTTY;
		 break; /* NOT REACHED */
	}

	 return r;
}

 /*
  * Check for disk specific ioctls.
  */

static int
disk_ioctl_switch(dev_t dev, u_long cmd, void *data)
{
	dm_dev_t *dmv;

	switch(cmd) {
	case DIOCGWEDGEINFO:
	{
		struct dkwedge_info *dkw = (void *) data;

		if ((dmv = dm_dev_lookup(NULL, NULL, minor(dev))) == NULL)
			return ENOENT;

		aprint_normal("DIOCGWEDGEINFO ioctl called\n");

		strlcpy(dkw->dkw_devname, dmv->name, 16);
		strlcpy(dkw->dkw_wname, dmv->name, DM_NAME_LEN);
		strlcpy(dkw->dkw_parent, dmv->name, 16);

		dkw->dkw_offset = 0;
		dkw->dkw_size = dm_table_size(&dmv->table_head);
		strcpy(dkw->dkw_ptype, DKW_PTYPE_FFS);

		dm_dev_unbusy(dmv);
		break;
	}

	case DIOCGDISKINFO:
	{
		struct plistref *pref = (struct plistref *) data;

		if ((dmv = dm_dev_lookup(NULL, NULL, minor(dev))) == NULL)
			return ENOENT;

		if (dmv->diskp->dk_info == NULL) {
			dm_dev_unbusy(dmv);
			return ENOTSUP;
		} else
			prop_dictionary_copyout_ioctl(pref, cmd,
			    dmv->diskp->dk_info);

		dm_dev_unbusy(dmv);

		break;
	}

	default:
		aprint_debug("unknown disk_ioctl called\n");
		return 1;
		break; /* NOT REACHED */
	}

	return 0;
}

/*
 * Do all IO operations on dm logical devices.
 */
static void
dmstrategy(struct buf *bp)
{
	dm_dev_t *dmv;
	dm_table_t  *tbl;
	dm_table_entry_t *table_en;
	struct buf *nestbuf;

	uint32_t dev_type;

	uint64_t buf_start, buf_len, issued_len;
	uint64_t table_start, table_end;
	uint64_t start, end;

	buf_start = bp->b_blkno * DEV_BSIZE;
	buf_len = bp->b_bcount;

	tbl = NULL;

	table_end = 0;
	dev_type = 0;
	issued_len = 0;

	if ((dmv = dm_dev_lookup(NULL, NULL, minor(bp->b_dev))) == NULL) {
		bp->b_error = EIO;
		bp->b_resid = bp->b_bcount;
		biodone(bp);
		return;
	}

	/* FIXME: have to be called with IPL_BIO*/
	disk_busy(dmv->diskp);

	/* Select active table */
	tbl = dm_table_get_entry(&dmv->table_head, DM_TABLE_ACTIVE);

	 /* Nested buffers count down to zero therefore I have
	    to set bp->b_resid to maximal value. */
	bp->b_resid = bp->b_bcount;

	/*
	 * Find out what tables I want to select.
	 */
	SLIST_FOREACH(table_en, tbl, next)
	{
		/* I need need number of bytes not blocks. */
		table_start = table_en->start * DEV_BSIZE;
		/*
		 * I have to sub 1 from table_en->length to prevent
		 * off by one error
		 */
		table_end = table_start + (table_en->length)* DEV_BSIZE;

		start = MAX(table_start, buf_start);

		end = MIN(table_end, buf_start + buf_len);

		aprint_debug("----------------------------------------\n");
		aprint_debug("table_start %010" PRIu64", table_end %010"
		    PRIu64 "\n", table_start, table_end);
		aprint_debug("buf_start %010" PRIu64", buf_len %010"
		    PRIu64"\n", buf_start, buf_len);
		aprint_debug("start-buf_start %010"PRIu64", end %010"
		    PRIu64"\n", start - buf_start, end);
		aprint_debug("start %010" PRIu64" , end %010"
                    PRIu64"\n", start, end);
		aprint_debug("\n----------------------------------------\n");

		if (start < end) {
			/* create nested buffer  */
			nestbuf = getiobuf(NULL, true);

			nestiobuf_setup(bp, nestbuf, start - buf_start,
			    (end - start));

			issued_len += end - start;

			/* I need number of blocks. */
			nestbuf->b_blkno = (start - table_start) / DEV_BSIZE;

			table_en->target->strategy(table_en, nestbuf);
		}
	}

	if (issued_len < buf_len)
		nestiobuf_done(bp, buf_len - issued_len, EINVAL);

	/* FIXME have to be called with SPL_BIO*/
	disk_unbusy(dmv->diskp, buf_len, bp != NULL ? bp->b_flags & B_READ : 0);

	dm_table_release(&dmv->table_head, DM_TABLE_ACTIVE);
	dm_dev_unbusy(dmv);

	return;
}


static int
dmread(dev_t dev, struct uio *uio, int flag)
{
	return (physio(dmstrategy, NULL, dev, B_READ, dmminphys, uio));
}

static int
dmwrite(dev_t dev, struct uio *uio, int flag)
{
	return (physio(dmstrategy, NULL, dev, B_WRITE, dmminphys, uio));
}

static int
dmsize(dev_t dev)
{
	dm_dev_t *dmv;
	uint64_t size;

	size = 0;

	if ((dmv = dm_dev_lookup(NULL, NULL, minor(dev))) == NULL)
			return -ENOENT;

	size = dm_table_size(&dmv->table_head);
	dm_dev_unbusy(dmv);

  	return size;
}

static void
dmminphys(struct buf *bp)
{
	bp->b_bcount = MIN(bp->b_bcount, MAXPHYS);
}

void
dmgetproperties(struct disk *disk, dm_table_head_t *head)
{
	prop_dictionary_t disk_info, odisk_info, geom;
	int dmp_size;

	dmp_size = dm_table_size(head);

	disk_info = prop_dictionary_create();

	prop_dictionary_set_cstring_nocopy(disk_info, "type", "ESDI");

	geom = prop_dictionary_create();

	prop_dictionary_set_uint64(geom, "sectors-per-unit", dmp_size);

	prop_dictionary_set_uint32(geom, "sector-size",
	    DEV_BSIZE /* XXX 512? */);

	prop_dictionary_set_uint32(geom, "sectors-per-track", 32);

	prop_dictionary_set_uint32(geom, "tracks-per-cylinder", 64);

	prop_dictionary_set_uint32(geom, "cylinders-per-unit", dmp_size / 2048);

	prop_dictionary_set(disk_info, "geometry", geom);
	prop_object_release(geom);

	odisk_info = disk->dk_info;

	disk->dk_info = disk_info;

	if (odisk_info != NULL)
		prop_object_release(odisk_info);
}