xref: /netbsd-src/sys/ufs/chfs/chfs_vfsops.c (revision 9ea3b23dafd978027b28369eda07bf00fb169b23)

/*	$NetBSD: chfs_vfsops.c,v 1.23 2022/03/19 13:53:32 hannken Exp $	*/

/*-
 * Copyright (c) 2010 Department of Software Engineering,
 *		      University of Szeged, Hungary
 * Copyright (C) 2010 Tamas Toth <ttoth@inf.u-szeged.hu>
 * Copyright (C) 2010 Adam Hoka <ahoka@NetBSD.org>
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by the Department of Software Engineering, University of Szeged, Hungary
 *
 * 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 AUTHOR ``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 AUTHOR 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.
 */

#include <sys/cdefs.h>

#include <sys/param.h>
#include <sys/types.h>
#include <sys/kmem.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/module.h>
#include <sys/namei.h>
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/buf.h>
//XXX needed just for debugging
#include <sys/fstrans.h>
#include <sys/sleepq.h>
#include <sys/lockdebug.h>
#include <sys/ktrace.h>

#include <uvm/uvm_extern.h>

#include <ufs/ufs/dir.h>
#include <ufs/ufs/ufs_extern.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/genfs/genfs_node.h>
#include <miscfs/specfs/specdev.h>
#include "chfs.h"
#include "chfs_args.h"

/* --------------------------------------------------------------------- */
/* functions */

static int chfs_mount(struct mount *, const char *, void *, size_t *);
static int chfs_unmount(struct mount *, int);
static int chfs_root(struct mount *, int, struct vnode **);
static int chfs_loadvnode(struct mount *, struct vnode *,
    const void *, size_t, const void **);
static int chfs_vget(struct mount *, ino_t, int, struct vnode **);
static int chfs_fhtovp(struct mount *, struct fid *, int, struct vnode **);
static int chfs_vptofh(struct vnode *, struct fid *, size_t *);
static int chfs_start(struct mount *, int);
static int chfs_statvfs(struct mount *, struct statvfs *);
static int chfs_sync(struct mount *, int, kauth_cred_t);
static void chfs_init(void);
static void chfs_reinit(void);
static void chfs_done(void);
static int chfs_snapshot(struct mount *, struct vnode *,
    struct timespec *);

/* --------------------------------------------------------------------- */
/* structures */

int
chfs_gop_alloc(struct vnode *vp, off_t off, off_t len,  int flags,
    kauth_cred_t cred)
{
	return (0);
}

const struct genfs_ops chfs_genfsops = {
	.gop_size = genfs_size,
	.gop_alloc = chfs_gop_alloc,
	.gop_write = genfs_gop_write,
	.gop_markupdate = ufs_gop_markupdate,
	.gop_putrange = genfs_gop_putrange,
};

struct pool chfs_inode_pool;

/* for looking up the major for flash */
extern const struct cdevsw flash_cdevsw;

/* --------------------------------------------------------------------- */

static int
chfs_mount(struct mount *mp,
    const char *path, void *data, size_t *data_len)
{
	struct lwp *l = curlwp;
	struct nameidata nd;
	struct pathbuf *pb;
	struct vnode *devvp = NULL;
	struct ufs_args *args = data;
	struct ufsmount *ump = NULL;
	struct chfs_mount *chmp;
	int err = 0;
	int xflags;

	dbg("mount()\n");

	if (args == NULL)
		return EINVAL;
	if (*data_len < sizeof *args)
		return EINVAL;

	if (mp->mnt_flag & MNT_GETARGS) {
		ump = VFSTOUFS(mp);
		if (ump == NULL)
			return EIO;
		memset(args, 0, sizeof *args);
		args->fspec = NULL;
		*data_len = sizeof *args;
		return 0;
	}

	if (mp->mnt_flag & MNT_UPDATE) {
		/* XXX: There is no support yet to update file system
		 * settings.  Should be added. */

		return ENODEV;
	}

	if (args->fspec != NULL) {
		err = pathbuf_copyin(args->fspec, &pb);
		if (err) {
			return err;
		}
		/* Look up the name and verify that it's sane. */
		NDINIT(&nd, LOOKUP, FOLLOW, pb);
		err = namei(&nd);
		pathbuf_destroy(pb);
		if (err)
			return err;
		devvp = nd.ni_vp;

		/* Be sure this is a valid block device */
		if (devvp->v_type != VBLK)
			err = ENOTBLK;
		else if (bdevsw_lookup(devvp->v_rdev) == NULL)
			err = ENXIO;
	}

	if (err) {
		vrele(devvp);
		return (err);
	}

	if (mp->mnt_flag & MNT_RDONLY)
		xflags = FREAD;
	else
		xflags = FREAD|FWRITE;

	err = VOP_OPEN(devvp, xflags, FSCRED);
	if (err)
		goto fail;

	/* call CHFS mount function */
	err = chfs_mountfs(devvp, mp);
	if (err) {
		vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
		(void)VOP_CLOSE(devvp, xflags, NOCRED);
		VOP_UNLOCK(devvp);
		goto fail;
	}

	ump = VFSTOUFS(mp);
	chmp = ump->um_chfs;

	vfs_getnewfsid(mp);
	chmp->chm_fsmp = mp;

	return set_statvfs_info(path,
	    UIO_USERSPACE, args->fspec,
	    UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l);

fail:
	vrele(devvp);
	return (err);
}

/* chfs_mountfs - init CHFS */
int
chfs_mountfs(struct vnode *devvp, struct mount *mp)
{
	struct lwp *l = curlwp;
	kauth_cred_t cred;
	devmajor_t flash_major;
	dev_t dev;
	struct ufsmount* ump = NULL;
	struct chfs_mount* chmp;
	struct vnode *vp;
	int err = 0;

	dbg("mountfs()\n");

	dev = devvp->v_rdev;
	cred = l ? l->l_cred : NOCRED;

	/* Flush out any old buffers remaining from a previous use. */
	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
	err = vinvalbuf(devvp, V_SAVE, cred, l, 0, 0);
	VOP_UNLOCK(devvp);
	if (err)
		goto fail0;

	/* Setup device. */
	flash_major = cdevsw_lookup_major(&flash_cdevsw);

	if (devvp->v_type != VBLK)
		err = ENOTBLK;
	else if (bdevsw_lookup(dev) == NULL)
		err = ENXIO;
	else if (major(dev) != flash_major) {
		dbg("major(dev): %d, flash_major: %d\n",
		    major(dev), flash_major);
		err = ENODEV;
	}
	if (err)
		goto fail0;

	/* Connect CHFS to UFS. */
	ump = kmem_zalloc(sizeof(struct ufsmount), KM_SLEEP);

	ump->um_fstype = UFS1;
	ump->um_chfs = kmem_zalloc(sizeof(struct chfs_mount), KM_SLEEP);
	mutex_init(&ump->um_lock, MUTEX_DEFAULT, IPL_NONE);

	chmp = ump->um_chfs;

	/* Initialize erase block handler. */
	chmp->chm_ebh = kmem_alloc(sizeof(struct chfs_ebh), KM_SLEEP);

	dbg("[]opening flash: %u\n", (unsigned int)devvp->v_rdev);
	err = ebh_open(chmp->chm_ebh, devvp->v_rdev);
	if (err) {
		dbg("error while opening flash\n");
		goto fail1;
	}

	//TODO check flash sizes

	/* Initialize vnode cache's hashtable and eraseblock array. */
	chmp->chm_gbl_version = 0;
	chmp->chm_vnocache_hash = chfs_vnocache_hash_init();

	chmp->chm_blocks = kmem_zalloc(chmp->chm_ebh->peb_nr *
	    sizeof(struct chfs_eraseblock), KM_SLEEP);

	/* Initialize mutexes. */
	mutex_init(&chmp->chm_lock_mountfields, MUTEX_DEFAULT, IPL_NONE);
	mutex_init(&chmp->chm_lock_sizes, MUTEX_DEFAULT, IPL_NONE);
	mutex_init(&chmp->chm_lock_vnocache, MUTEX_DEFAULT, IPL_NONE);

	/* Initialize read/write contants. (from UFS) */
	chmp->chm_fs_bmask = -4096;
	chmp->chm_fs_bsize = 4096;
	chmp->chm_fs_qbmask = 4095;
	chmp->chm_fs_bshift = 12;
	chmp->chm_fs_fmask = -2048;
	chmp->chm_fs_qfmask = 2047;

	/* Initialize writebuffer. */
	chmp->chm_wbuf_pagesize = chmp->chm_ebh->flash_if->page_size;
	dbg("wbuf size: %zu\n", chmp->chm_wbuf_pagesize);
	chmp->chm_wbuf = kmem_alloc(chmp->chm_wbuf_pagesize, KM_SLEEP);
	rw_init(&chmp->chm_lock_wbuf);

	/* Initialize queues. */
	TAILQ_INIT(&chmp->chm_free_queue);
	TAILQ_INIT(&chmp->chm_clean_queue);
	TAILQ_INIT(&chmp->chm_dirty_queue);
	TAILQ_INIT(&chmp->chm_very_dirty_queue);
	TAILQ_INIT(&chmp->chm_erasable_pending_wbuf_queue);
	TAILQ_INIT(&chmp->chm_erase_pending_queue);

	/* Initialize flash-specific constants. */
	chfs_calc_trigger_levels(chmp);

	/* Initialize sizes. */
	chmp->chm_nr_free_blocks = 0;
	chmp->chm_nr_erasable_blocks = 0;
	chmp->chm_max_vno = 2;
	chmp->chm_checked_vno = 2;
	chmp->chm_unchecked_size = 0;
	chmp->chm_used_size = 0;
	chmp->chm_dirty_size = 0;
	chmp->chm_wasted_size = 0;
	chmp->chm_free_size = chmp->chm_ebh->eb_size * chmp->chm_ebh->peb_nr;

	/* Build filesystem. */
	err = chfs_build_filesystem(chmp);

	if (err) {
		/* Armageddon and return. */
		err = EIO;
		goto fail2;
	}

	/* Initialize UFS. */
	mp->mnt_data = ump;
	mp->mnt_stat.f_fsidx.__fsid_val[0] = (long)dev;
	mp->mnt_stat.f_fsidx.__fsid_val[1] = makefstype(MOUNT_CHFS);
	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
	mp->mnt_stat.f_namemax = MAXNAMLEN;
	mp->mnt_flag |= MNT_LOCAL;
	mp->mnt_fs_bshift = PAGE_SHIFT;
	mp->mnt_dev_bshift = DEV_BSHIFT;
	mp->mnt_iflag |= IMNT_MPSAFE;
	ump->um_flags = 0;
	ump->um_mountp = mp;
	ump->um_dev = dev;
	ump->um_devvp = devvp;
	ump->um_maxfilesize = 1048512 * 1024;

	/* Allocate the root vnode. */
	err = VFS_VGET(mp, CHFS_ROOTINO, LK_EXCLUSIVE, &vp);
	if (err) {
		dbg("error: %d while allocating root node\n", err);
		return err;
	}
	vput(vp);

	/* Start GC. */
	chfs_gc_thread_start(chmp);
	mutex_enter(&chmp->chm_lock_mountfields);
	chfs_gc_trigger(chmp);
	mutex_exit(&chmp->chm_lock_mountfields);

	spec_node_setmountedfs(devvp, mp);
	return 0;

fail2:
	KASSERT(TAILQ_EMPTY(&chmp->chm_erase_pending_queue));
	KASSERT(TAILQ_EMPTY(&chmp->chm_erasable_pending_wbuf_queue));
	KASSERT(TAILQ_EMPTY(&chmp->chm_very_dirty_queue));
	KASSERT(TAILQ_EMPTY(&chmp->chm_dirty_queue));
	KASSERT(TAILQ_EMPTY(&chmp->chm_clean_queue));
	KASSERT(TAILQ_EMPTY(&chmp->chm_free_queue));
	rw_destroy(&chmp->chm_lock_wbuf);
	kmem_free(chmp->chm_wbuf, chmp->chm_wbuf_pagesize);
	mutex_destroy(&chmp->chm_lock_vnocache);
	mutex_destroy(&chmp->chm_lock_sizes);
	mutex_destroy(&chmp->chm_lock_mountfields);
	kmem_free(chmp->chm_blocks, chmp->chm_ebh->peb_nr *
	    sizeof(struct chfs_eraseblock));
	chfs_vnocache_hash_destroy(chmp->chm_vnocache_hash);
	ebh_close(chmp->chm_ebh);

fail1:
	kmem_free(chmp->chm_ebh, sizeof(struct chfs_ebh));
	mutex_destroy(&ump->um_lock);
	kmem_free(chmp, sizeof(struct chfs_mount));
	kmem_free(ump, sizeof(struct ufsmount));

fail0:
	KASSERT(err);
	return err;
}

/* --------------------------------------------------------------------- */

static int
chfs_unmount(struct mount *mp, int mntflags)
{
	int flags = 0, i = 0;
	struct ufsmount *ump;
	struct chfs_mount *chmp;

	if (mntflags & MNT_FORCE)
		flags |= FORCECLOSE;

	dbg("[START]\n");

	ump = VFSTOUFS(mp);
	chmp = ump->um_chfs;

	/* Stop GC. */
	chfs_gc_thread_stop(chmp);

	/* Flush everyt buffer. */
	(void)vflush(mp, NULLVP, flags);

	if (chmp->chm_wbuf_len) {
		mutex_enter(&chmp->chm_lock_mountfields);
		chfs_flush_pending_wbuf(chmp);
		mutex_exit(&chmp->chm_lock_mountfields);
	}

	/* Free node references. */
	for (i = 0; i < chmp->chm_ebh->peb_nr; i++) {
		chfs_free_node_refs(&chmp->chm_blocks[i]);
	}

	/* Destroy vnode cache hashtable. */
	chfs_vnocache_hash_destroy(chmp->chm_vnocache_hash);

	/* Close eraseblock handler. */
	ebh_close(chmp->chm_ebh);

	/* Destroy mutexes. */
	rw_destroy(&chmp->chm_lock_wbuf);
	mutex_destroy(&chmp->chm_lock_vnocache);
	mutex_destroy(&chmp->chm_lock_sizes);
	mutex_destroy(&chmp->chm_lock_mountfields);

	/* Unmount UFS. */
	if (ump->um_devvp->v_type != VBAD) {
		spec_node_setmountedfs(ump->um_devvp, NULL);
	}
	vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
	(void)VOP_CLOSE(ump->um_devvp, FREAD|FWRITE, NOCRED);
	vput(ump->um_devvp);

	mutex_destroy(&ump->um_lock);

	/* Everything done. */
	kmem_free(ump, sizeof(struct ufsmount));
	mp->mnt_data = NULL;
	mp->mnt_flag &= ~MNT_LOCAL;
	dbg("[END]\n");
	return (0);
}

/* --------------------------------------------------------------------- */

static int
chfs_root(struct mount *mp, int lktype, struct vnode **vpp)
{
	struct vnode *vp;
	int error;

	if ((error = VFS_VGET(mp, (ino_t)UFS_ROOTINO, lktype, &vp)) != 0)
		return error;
	*vpp = vp;
	return 0;
}

/* --------------------------------------------------------------------- */

extern rb_tree_ops_t frag_rbtree_ops;

static int
chfs_loadvnode(struct mount *mp, struct vnode *vp,
    const void *key, size_t key_len, const void **new_key)
{
	struct chfs_mount *chmp;
	struct chfs_inode *ip;
	struct ufsmount *ump;
	dev_t dev;
	int error;
	struct chfs_vnode_cache* chvc = NULL;
	struct chfs_node_ref* nref = NULL;
	struct buf *bp;
	ino_t ino;

	KASSERT(key_len == sizeof(ino));
	memcpy(&ino, key, key_len);

	dbg("vget() | ino: %llu\n", (unsigned long long)ino);

	ump = VFSTOUFS(mp);
	dev = ump->um_dev;

	ip = pool_get(&chfs_inode_pool, PR_WAITOK);

	/* Initialize vnode/inode. */
	memset(ip, 0, sizeof(*ip));
	ip->vp = vp;
	ip->ump = ump;
	ip->chmp = chmp = ump->um_chfs;
	ip->dev = dev;
	ip->ino = ino;

	rb_tree_init(&ip->fragtree, &frag_rbtree_ops);

	vp->v_tag = VT_CHFS;
	vp->v_op = chfs_vnodeop_p;
	if (ino == CHFS_ROOTINO)
		vp->v_vflag |= VV_ROOT;
	vp->v_data = ip;

	/* Set root inode. */
	if (ino == CHFS_ROOTINO) {
		dbg("SETROOT\n");
		vp->v_type = VDIR;
		ip->ch_type = CHT_DIR;
		ip->mode = IFMT | IEXEC | IWRITE | IREAD;
		ip->iflag |= (IN_ACCESS | IN_CHANGE | IN_UPDATE);
		chfs_update(vp, NULL, NULL, UPDATE_WAIT);
		TAILQ_INIT(&ip->dents);
		chfs_set_vnode_size(vp, 512);
	}

	mutex_enter(&chmp->chm_lock_vnocache);
	chvc = chfs_vnode_cache_get(chmp, ino);
	mutex_exit(&chmp->chm_lock_vnocache);
	if (!chvc) {
		dbg("!chvc\n");
		/* Initialize the corresponding vnode cache. */
		/* XXX, we cant alloc under a lock, refactor this! */
		chvc = chfs_vnode_cache_alloc(ino);
		mutex_enter(&chmp->chm_lock_vnocache);
		if (ino == CHFS_ROOTINO) {
			chvc->nlink = 2;
			chvc->pvno = CHFS_ROOTINO;
			chvc->state = VNO_STATE_CHECKEDABSENT;
		}
		chfs_vnode_cache_add(chmp, chvc);
		mutex_exit(&chmp->chm_lock_vnocache);

		ip->chvc = chvc;
		TAILQ_INIT(&ip->dents);
	} else {
		dbg("chvc\n");
		ip->chvc = chvc;
		/* We had a vnode cache, the node is already on flash, so read it */
		if (ino == CHFS_ROOTINO) {
			chvc->pvno = CHFS_ROOTINO;
			TAILQ_INIT(&chvc->scan_dirents);
		} else {
			chfs_readvnode(mp, ino, &vp);
		}

		mutex_enter(&chmp->chm_lock_mountfields);
		/* Initialize type specific things. */
		error = 0;
		switch (ip->ch_type) {
		case CHT_DIR:
			/* Read every dirent. */
			nref = chvc->dirents;
			while (nref &&
			    (struct chfs_vnode_cache *)nref != chvc) {
				chfs_readdirent(mp, nref, ip);
				nref = nref->nref_next;
			}
			chfs_set_vnode_size(vp, 512);
			break;
		case CHT_REG:
			/* FALLTHROUGH */
		case CHT_SOCK:
			/* Collect data. */
			dbg("read_inode_internal | ino: %llu\n",
				(unsigned long long)ip->ino);
			error = chfs_read_inode(chmp, ip);
			break;
		case CHT_LNK:
			/* Collect data. */
			dbg("read_inode_internal | ino: %llu\n",
				(unsigned long long)ip->ino);
			error = chfs_read_inode_internal(chmp, ip);
			if (error)
				break;

			/* Set link. */
			dbg("size: %llu\n", (unsigned long long)ip->size);
			bp = getiobuf(vp, true);
			bp->b_blkno = 0;
			bp->b_bufsize = bp->b_resid =
			    bp->b_bcount = ip->size;
			bp->b_data = kmem_alloc(ip->size, KM_SLEEP);
			chfs_read_data(chmp, vp, bp);
			if (!ip->target)
				ip->target = kmem_alloc(ip->size,
				    KM_SLEEP);
			memcpy(ip->target, bp->b_data, ip->size);
			kmem_free(bp->b_data, ip->size);
			putiobuf(bp);

			break;
		case CHT_CHR:
			/* FALLTHROUGH */
		case CHT_BLK:
			/* FALLTHROUGH */
		case CHT_FIFO:
			/* Collect data. */
			dbg("read_inode_internal | ino: %llu\n",
				(unsigned long long)ip->ino);
			error = chfs_read_inode_internal(chmp, ip);
			if (error)
				break;

			/* Set device. */
			bp = getiobuf(vp, true);
			bp->b_blkno = 0;
			bp->b_bufsize = bp->b_resid =
			    bp->b_bcount = sizeof(dev_t);
			bp->b_data = kmem_alloc(sizeof(dev_t), KM_SLEEP);
			chfs_read_data(chmp, vp, bp);
			memcpy(&ip->rdev,
			    bp->b_data, sizeof(dev_t));
			kmem_free(bp->b_data, sizeof(dev_t));
			putiobuf(bp);
			/* Set specific operations. */
			if (ip->ch_type == CHT_FIFO) {
				vp->v_op = chfs_fifoop_p;
			} else {
				vp->v_op = chfs_specop_p;
				spec_node_init(vp, ip->rdev);
			}

		    break;
		case CHT_BLANK:
			/* FALLTHROUGH */
		case CHT_BAD:
			break;
		}
		mutex_exit(&chmp->chm_lock_mountfields);
		if (error) {
			vp->v_data = NULL;
			KASSERT(TAILQ_FIRST(&ip->dents) == NULL);
			pool_put(&chfs_inode_pool, ip);
			return error;
		}

	}

	/* Finish inode initialization. */
	ip->ch_type = VTTOCHT(vp->v_type);
	ip->devvp = ump->um_devvp;
	vref(ip->devvp);

	genfs_node_init(vp, &chfs_genfsops);
	uvm_vnp_setsize(vp, ip->size);

	*new_key = &ip->ino;

	return 0;
}

/* --------------------------------------------------------------------- */

static int
chfs_vget(struct mount *mp, ino_t ino, int lktype, struct vnode **vpp)
{
	int error;

	error = vcache_get(mp, &ino, sizeof(ino), vpp);
	if (error)
		return error;

	error = vn_lock(*vpp, lktype);
	if (error) {
		vrele(*vpp);
		*vpp = NULL;
		return error;
	}

	return 0;
}

/* --------------------------------------------------------------------- */


static int
chfs_fhtovp(struct mount *mp, struct fid *fhp, int lktype, struct vnode **vpp)
{
	return ENODEV;
}

/* --------------------------------------------------------------------- */

static int
chfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
{
	return ENODEV;
}

/* --------------------------------------------------------------------- */

static int
chfs_start(struct mount *mp, int flags)
{
	return 0;
}

/* --------------------------------------------------------------------- */

static int
chfs_statvfs(struct mount *mp, struct statvfs *sbp)
{
 	struct chfs_mount *chmp;
	struct ufsmount *ump;
	dbg("statvfs\n");

	ump = VFSTOUFS(mp);
	chmp = ump->um_chfs;

	sbp->f_flag   = mp->mnt_flag;
	sbp->f_bsize  = chmp->chm_ebh->eb_size;
	sbp->f_frsize = chmp->chm_ebh->eb_size;
	sbp->f_iosize = chmp->chm_ebh->eb_size;

	sbp->f_blocks = chmp->chm_ebh->peb_nr;
	sbp->f_files  = 0;
	sbp->f_bavail = chmp->chm_nr_free_blocks - chmp->chm_resv_blocks_write;

	sbp->f_bfree = chmp->chm_nr_free_blocks;
	sbp->f_bresvd = chmp->chm_resv_blocks_write;

	/* FFS specific */
	sbp->f_ffree  = 0;
	sbp->f_favail = 0;
	sbp->f_fresvd = 0;

	copy_statvfs_info(sbp, mp);

	return 0;
}

/* --------------------------------------------------------------------- */

static int
chfs_sync(struct mount *mp, int waitfor,
    kauth_cred_t uc)
{
	return 0;
}

/* --------------------------------------------------------------------- */

static void
chfs_init(void)
{
	/* Initialize pools and inode hash. */
	chfs_alloc_pool_caches();
	pool_init(&chfs_inode_pool, sizeof(struct chfs_inode), 0, 0, 0,
	    "chfsinopl", &pool_allocator_nointr, IPL_NONE);
	ufs_init();
}

/* --------------------------------------------------------------------- */

static void
chfs_reinit(void)
{
	ufs_reinit();
}

/* --------------------------------------------------------------------- */

static void
chfs_done(void)
{
	ufs_done();
	pool_destroy(&chfs_inode_pool);
	chfs_destroy_pool_caches();
}

/* --------------------------------------------------------------------- */

static int
chfs_snapshot(struct mount *mp, struct vnode *vp,
    struct timespec *ctime)
{
	return ENODEV;
}

/* --------------------------------------------------------------------- */

/*
 * chfs vfs operations.
 */

extern const struct vnodeopv_desc chfs_fifoop_opv_desc;
extern const struct vnodeopv_desc chfs_specop_opv_desc;
extern const struct vnodeopv_desc chfs_vnodeop_opv_desc;

const struct vnodeopv_desc * const chfs_vnodeopv_descs[] = {
	&chfs_fifoop_opv_desc,
	&chfs_specop_opv_desc,
	&chfs_vnodeop_opv_desc,
	NULL,
};

struct vfsops chfs_vfsops = {
	.vfs_name = MOUNT_CHFS,
	.vfs_min_mount_data = sizeof (struct chfs_args),
	.vfs_mount = chfs_mount,
	.vfs_start = chfs_start,
	.vfs_unmount = chfs_unmount,
	.vfs_root = chfs_root,
	.vfs_quotactl = ufs_quotactl,
	.vfs_statvfs = chfs_statvfs,
	.vfs_sync = chfs_sync,
	.vfs_vget = chfs_vget,
	.vfs_loadvnode = chfs_loadvnode,
	.vfs_fhtovp = chfs_fhtovp,
	.vfs_vptofh = chfs_vptofh,
	.vfs_init = chfs_init,
	.vfs_reinit = chfs_reinit,
	.vfs_done = chfs_done,
	.vfs_snapshot = chfs_snapshot,
	.vfs_extattrctl = vfs_stdextattrctl,
	.vfs_suspendctl = genfs_suspendctl,
	.vfs_renamelock_enter = genfs_renamelock_enter,
	.vfs_renamelock_exit = genfs_renamelock_exit,
	.vfs_fsync = (void *)eopnotsupp,
	.vfs_opv_descs = chfs_vnodeopv_descs
};

/* For using CHFS as a module. */

MODULE(MODULE_CLASS_VFS, chfs, "ufs,flash");

static int
chfs_modcmd(modcmd_t cmd, void *arg)
{
	switch (cmd) {
	case MODULE_CMD_INIT:
		return vfs_attach(&chfs_vfsops);
	case MODULE_CMD_FINI:
		return vfs_detach(&chfs_vfsops);
	default:
		return ENOTTY;
	}
}