/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/zfs_context.h>

#include <sys/spa.h>

#include <sys/vdev_disk.h>

#include <sys/vdev_impl.h>

#include <sys/fs/zfs.h>

#include <sys/zio.h>

#include <sys/sunldi.h>

/*

 * Virtual device vector for disks.

 */

extern ldi_ident_t zfs_li;

typedef struct vdev_disk_buf {

	buf_t	vdb_buf;

	zio_t	*vdb_io;

} vdev_disk_buf_t;

static int

vdev_disk_open(vdev_t *vd, uint64_t *psize, uint64_t *ashift)

{

	vdev_disk_t *dvd;

	struct dk_minfo dkm;

	int error;

	/*

	 * We must have a pathname, and it must be absolute.

	 */

	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {

		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;

		return (EINVAL);

	}

	dvd = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_disk_t), KM_SLEEP);

	/*

	 * When opening a disk device, we want to preserve the user's original

	 * intent.  We always want to open the device by the path the user gave

	 * us, even if it is one of multiple paths to the save device.  But we

	 * also want to be able to survive disks being removed/recabled.

	 * Therefore the sequence of opening devices is:

	 *

	 * 1. Try opening the device by path.  For legacy pools without the

	 *    'whole_disk' property, attempt to fix the path by appending 's0'.

	 *

	 * 2. If the devid of the device matches the stored value, return

	 *    success.

	 *

	 * 3. Otherwise, the device may have moved.  Try opening the device

	 *    by the devid instead.

	 *

	 */

	if (vd->vdev_devid != NULL) {

		if (ddi_devid_str_decode(vd->vdev_devid, &dvd->vd_devid,

		    &dvd->vd_minor) != 0) {

			vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;

			return (EINVAL);

		}

	}

	error = EINVAL;		/* presume failure */

	if (vd->vdev_path != NULL) {

		ddi_devid_t devid;

		if (vd->vdev_wholedisk == -1ULL) {

			size_t len = strlen(vd->vdev_path) + 3;

			char *buf = kmem_alloc(len, KM_SLEEP);

			ldi_handle_t lh;

			(void) snprintf(buf, len, "%ss0", vd->vdev_path);

			if (ldi_open_by_name(buf, spa_mode, kcred,

			    &lh, zfs_li) == 0) {

				spa_strfree(vd->vdev_path);

				vd->vdev_path = buf;

				vd->vdev_wholedisk = 1ULL;

				(void) ldi_close(lh, spa_mode, kcred);

			} else {

				kmem_free(buf, len);

			}

		}

		error = ldi_open_by_name(vd->vdev_path, spa_mode, kcred,

		    &dvd->vd_lh, zfs_li);

		/*

		 * Compare the devid to the stored value.

		 */

		if (error == 0 && vd->vdev_devid != NULL &&

		    ldi_get_devid(dvd->vd_lh, &devid) == 0) {

			if (ddi_devid_compare(devid, dvd->vd_devid) != 0) {

				error = EINVAL;

				(void) ldi_close(dvd->vd_lh, spa_mode, kcred);

				dvd->vd_lh = NULL;

			}

			ddi_devid_free(devid);

		}

		/*

		 * If we succeeded in opening the device, but 'vdev_wholedisk'

		 * is not yet set, then this must be a slice.

		 */

		if (error == 0 && vd->vdev_wholedisk == -1ULL)

			vd->vdev_wholedisk = 0;

	}

	/*

	 * If we were unable to open by path, or the devid check fails, open by

	 * devid instead.

	 */

	if (error != 0 && vd->vdev_devid != NULL)

		error = ldi_open_by_devid(dvd->vd_devid, dvd->vd_minor,

		    spa_mode, kcred, &dvd->vd_lh, zfs_li);

	if (error) {

		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;

		return (error);

	}

	/*

	 * Determine the actual size of the device.

	 */

	if (ldi_get_size(dvd->vd_lh, psize) != 0) {

		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;

		return (EINVAL);

	}

	/*

	 * If we own the whole disk, try to enable disk write caching.

	 * We ignore errors because it's OK if we can't do it.

	 */

	if (vd->vdev_wholedisk == 1) {

		int wce = 1;

		(void) ldi_ioctl(dvd->vd_lh, DKIOCSETWCE, (intptr_t)&wce,

		    FKIOCTL, kcred, NULL);

	}

	/*

	 * Determine the device's minimum transfer size.

	 * If the ioctl isn't supported, assume DEV_BSIZE.

	 */

	if (ldi_ioctl(dvd->vd_lh, DKIOCGMEDIAINFO, (intptr_t)&dkm,

	    FKIOCTL, kcred, NULL) != 0)

		dkm.dki_lbsize = DEV_BSIZE;

	*ashift = highbit(MAX(dkm.dki_lbsize, SPA_MINBLOCKSIZE)) - 1;

	/*

	 * Clear the nowritecache bit, so that on a vdev_reopen() we will

	 * try again.

	 */

	vd->vdev_nowritecache = B_FALSE;

	return (0);

}

static void

vdev_disk_close(vdev_t *vd)

{

	vdev_disk_t *dvd = vd->vdev_tsd;

	if (dvd == NULL)

		return;

	dprintf("removing disk %s, devid %s\n",

	    vd->vdev_path ? vd->vdev_path : "<none>",

	    vd->vdev_devid ? vd->vdev_devid : "<none>");

	if (dvd->vd_minor != NULL)

		ddi_devid_str_free(dvd->vd_minor);

	if (dvd->vd_devid != NULL)

		ddi_devid_free(dvd->vd_devid);

	if (dvd->vd_lh != NULL)

		(void) ldi_close(dvd->vd_lh, spa_mode, kcred);

	kmem_free(dvd, sizeof (vdev_disk_t));

	vd->vdev_tsd = NULL;

}

static void

vdev_disk_io_intr(buf_t *bp)

{

	vdev_disk_buf_t *vdb = (vdev_disk_buf_t *)bp;

	zio_t *zio = vdb->vdb_io;

	if ((zio->io_error = geterror(bp)) == 0 && bp->b_resid != 0)

		zio->io_error = EIO;

	kmem_free(vdb, sizeof (vdev_disk_buf_t));

	zio_next_stage_async(zio);

}

static void

vdev_disk_ioctl_done(void *zio_arg, int error)

{

	zio_t *zio = zio_arg;

	zio->io_error = error;

	zio_next_stage_async(zio);

}

static void

vdev_disk_io_start(zio_t *zio)

{

	vdev_t *vd = zio->io_vd;

	vdev_disk_t *dvd = vd->vdev_tsd;

	vdev_disk_buf_t *vdb;

	buf_t *bp;

	int flags, error;

	if (zio->io_type == ZIO_TYPE_IOCTL) {

		zio_vdev_io_bypass(zio);

		/* XXPOLICY */

		if (vdev_is_dead(vd)) {

			zio->io_error = ENXIO;

			zio_next_stage_async(zio);

			return;

		}

		switch (zio->io_cmd) {

		case DKIOCFLUSHWRITECACHE:

			if (zfs_nocacheflush)

				break;

			if (vd->vdev_nowritecache) {

				zio->io_error = ENOTSUP;

				break;

			}

			zio->io_dk_callback.dkc_callback = vdev_disk_ioctl_done;

			zio->io_dk_callback.dkc_cookie = zio;

			error = ldi_ioctl(dvd->vd_lh, zio->io_cmd,

			    (uintptr_t)&zio->io_dk_callback,

			    FKIOCTL, kcred, NULL);

			if (error == 0) {

				/*

				 * The ioctl will be done asychronously,

				 * and will call vdev_disk_ioctl_done()

				 * upon completion.

				 */

				return;

			} else if (error == ENOTSUP) {

				/*

				 * If we get ENOTSUP, we know that no future

				 * attempts will ever succeed.  In this case we

				 * set a persistent bit so that we don't bother

				 * with the ioctl in the future.

				 */

				vd->vdev_nowritecache = B_TRUE;

			}

			zio->io_error = error;

			break;

		default:

			zio->io_error = ENOTSUP;

		}

		zio_next_stage_async(zio);

		return;

	}

	if (zio->io_type == ZIO_TYPE_READ && vdev_cache_read(zio) == 0)

		return;

	if ((zio = vdev_queue_io(zio)) == NULL)

		return;

	flags = (zio->io_type == ZIO_TYPE_READ ? B_READ : B_WRITE);

	flags |= B_BUSY | B_NOCACHE;

	if (zio->io_flags & ZIO_FLAG_FAILFAST)

		flags |= B_FAILFAST;

	vdb = kmem_alloc(sizeof (vdev_disk_buf_t), KM_SLEEP);

	vdb->vdb_io = zio;

	bp = &vdb->vdb_buf;

	bioinit(bp);

	bp->b_flags = flags;

	bp->b_bcount = zio->io_size;

	bp->b_un.b_addr = zio->io_data;

	bp->b_lblkno = lbtodb(zio->io_offset);

	bp->b_bufsize = zio->io_size;

	bp->b_iodone = (int (*)())vdev_disk_io_intr;

	/* XXPOLICY */

	error = vdev_is_dead(vd) ? ENXIO : vdev_error_inject(vd, zio);

	if (error) {

		zio->io_error = error;

		bioerror(bp, error);

		bp->b_resid = bp->b_bcount;

		bp->b_iodone(bp);

		return;

	}

	error = ldi_strategy(dvd->vd_lh, bp);

	/* ldi_strategy() will return non-zero only on programming errors */

	ASSERT(error == 0);

}

static void

vdev_disk_io_done(zio_t *zio)

{

	vdev_queue_io_done(zio);

	if (zio->io_type == ZIO_TYPE_WRITE)

		vdev_cache_write(zio);

	if (zio_injection_enabled && zio->io_error == 0)

		zio->io_error = zio_handle_device_injection(zio->io_vd, EIO);

	zio_next_stage(zio);

}

vdev_ops_t vdev_disk_ops = {

	vdev_disk_open,

	vdev_disk_close,

	vdev_default_asize,

	vdev_disk_io_start,

	vdev_disk_io_done,

	NULL,

	VDEV_TYPE_DISK,		/* name of this vdev type */

	B_TRUE			/* leaf vdev */

};