diff --git a/sys/fs/ext2fs/ext2_vfsops.c b/sys/fs/ext2fs/ext2_vfsops.c
index 0ab0327ae074..b89786b2c2e2 100644
--- a/sys/fs/ext2fs/ext2_vfsops.c
+++ b/sys/fs/ext2fs/ext2_vfsops.c
@@ -1,1459 +1,1452 @@
 /*-
  *  modified for EXT2FS support in Lites 1.1
  *
  *  Aug 1995, Godmar Back (gback@cs.utah.edu)
  *  University of Utah, Department of Computer Science
  */
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1989, 1991, 1993, 1994
  *	The Regents of the University of California.  All rights reserved.
  *
  * 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.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
  *
  *	@(#)ffs_vfsops.c	8.8 (Berkeley) 4/18/94
  * $FreeBSD$
  */
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/namei.h>
 #include <sys/priv.h>
 #include <sys/proc.h>
 #include <sys/kernel.h>
 #include <sys/vnode.h>
 #include <sys/mount.h>
 #include <sys/bio.h>
 #include <sys/buf.h>
 #include <sys/conf.h>
 #include <sys/endian.h>
 #include <sys/fcntl.h>
 #include <sys/malloc.h>
 #include <sys/sdt.h>
 #include <sys/stat.h>
 #include <sys/mutex.h>
 
 #include <geom/geom.h>
 #include <geom/geom_vfs.h>
 
 #include <fs/ext2fs/fs.h>
 #include <fs/ext2fs/ext2_mount.h>
 #include <fs/ext2fs/inode.h>
 
 #include <fs/ext2fs/ext2fs.h>
 #include <fs/ext2fs/ext2_dinode.h>
 #include <fs/ext2fs/ext2_extern.h>
 #include <fs/ext2fs/ext2_extents.h>
 
 SDT_PROVIDER_DECLARE(ext2fs);
 /*
  * ext2fs trace probe:
  * arg0: verbosity. Higher numbers give more verbose messages
  * arg1: Textual message
  */
 SDT_PROBE_DEFINE2(ext2fs, , vfsops, trace, "int", "char*");
 SDT_PROBE_DEFINE2(ext2fs, , vfsops, ext2_cg_validate_error, "char*", "int");
 SDT_PROBE_DEFINE1(ext2fs, , vfsops, ext2_compute_sb_data_error, "char*");
 
 static int	ext2_flushfiles(struct mount *mp, int flags, struct thread *td);
 static int	ext2_mountfs(struct vnode *, struct mount *);
 static int	ext2_reload(struct mount *mp, struct thread *td);
 static int	ext2_sbupdate(struct ext2mount *, int);
 static int	ext2_cgupdate(struct ext2mount *, int);
 static vfs_unmount_t		ext2_unmount;
 static vfs_root_t		ext2_root;
 static vfs_statfs_t		ext2_statfs;
 static vfs_sync_t		ext2_sync;
 static vfs_vget_t		ext2_vget;
 static vfs_fhtovp_t		ext2_fhtovp;
 static vfs_mount_t		ext2_mount;
 
 MALLOC_DEFINE(M_EXT2NODE, "ext2_node", "EXT2 vnode private part");
 static MALLOC_DEFINE(M_EXT2MNT, "ext2_mount", "EXT2 mount structure");
 
 static struct vfsops ext2fs_vfsops = {
 	.vfs_fhtovp =		ext2_fhtovp,
 	.vfs_mount =		ext2_mount,
 	.vfs_root =		ext2_root,	/* root inode via vget */
 	.vfs_statfs =		ext2_statfs,
 	.vfs_sync =		ext2_sync,
 	.vfs_unmount =		ext2_unmount,
 	.vfs_vget =		ext2_vget,
 };
 
 VFS_SET(ext2fs_vfsops, ext2fs, 0);
 
 static int	ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev,
 		    int ronly);
 static int	ext2_compute_sb_data(struct vnode * devvp,
 		    struct ext2fs * es, struct m_ext2fs * fs);
 
 static const char *ext2_opts[] = { "acls", "async", "noatime", "noclusterr", 
     "noclusterw", "noexec", "export", "force", "from", "multilabel",
     "suiddir", "nosymfollow", "sync", "union", NULL };
 
 /*
  * VFS Operations.
  *
  * mount system call
  */
 static int
 ext2_mount(struct mount *mp)
 {
 	struct vfsoptlist *opts;
 	struct vnode *devvp;
 	struct thread *td;
 	struct ext2mount *ump = NULL;
 	struct m_ext2fs *fs;
 	struct nameidata nd, *ndp = &nd;
 	accmode_t accmode;
 	char *path, *fspec;
 	int error, flags, len;
 
 	td = curthread;
 	opts = mp->mnt_optnew;
 
 	if (vfs_filteropt(opts, ext2_opts))
 		return (EINVAL);
 
 	vfs_getopt(opts, "fspath", (void **)&path, NULL);
 	/* Double-check the length of path.. */
 	if (strlen(path) >= MAXMNTLEN)
 		return (ENAMETOOLONG);
 
 	fspec = NULL;
 	error = vfs_getopt(opts, "from", (void **)&fspec, &len);
 	if (!error && fspec[len - 1] != '\0')
 		return (EINVAL);
 
 	/*
 	 * If updating, check whether changing from read-only to
 	 * read/write; if there is no device name, that's all we do.
 	 */
 	if (mp->mnt_flag & MNT_UPDATE) {
 		ump = VFSTOEXT2(mp);
 		fs = ump->um_e2fs;
 		error = 0;
 		if (fs->e2fs_ronly == 0 &&
 		    vfs_flagopt(opts, "ro", NULL, 0)) {
 			error = VFS_SYNC(mp, MNT_WAIT);
 			if (error)
 				return (error);
 			flags = WRITECLOSE;
 			if (mp->mnt_flag & MNT_FORCE)
 				flags |= FORCECLOSE;
 			error = ext2_flushfiles(mp, flags, td);
 			if (error == 0 && fs->e2fs_wasvalid &&
 			    ext2_cgupdate(ump, MNT_WAIT) == 0) {
 				fs->e2fs->e2fs_state =
 				    htole16((le16toh(fs->e2fs->e2fs_state) |
 				    E2FS_ISCLEAN));
 				ext2_sbupdate(ump, MNT_WAIT);
 			}
 			fs->e2fs_ronly = 1;
 			vfs_flagopt(opts, "ro", &mp->mnt_flag, MNT_RDONLY);
 			g_topology_lock();
 			g_access(ump->um_cp, 0, -1, 0);
 			g_topology_unlock();
 		}
 		if (!error && (mp->mnt_flag & MNT_RELOAD))
 			error = ext2_reload(mp, td);
 		if (error)
 			return (error);
 		devvp = ump->um_devvp;
 		if (fs->e2fs_ronly && !vfs_flagopt(opts, "ro", NULL, 0)) {
 			if (ext2_check_sb_compat(fs->e2fs, devvp->v_rdev, 0))
 				return (EPERM);
 
 			/*
 			 * If upgrade to read-write by non-root, then verify
 			 * that user has necessary permissions on the device.
 			 */
 			vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
 			error = VOP_ACCESS(devvp, VREAD | VWRITE,
 			    td->td_ucred, td);
 			if (error)
 				error = priv_check(td, PRIV_VFS_MOUNT_PERM);
 			if (error) {
 				VOP_UNLOCK(devvp);
 				return (error);
 			}
 			VOP_UNLOCK(devvp);
 			g_topology_lock();
 			error = g_access(ump->um_cp, 0, 1, 0);
 			g_topology_unlock();
 			if (error)
 				return (error);
 
 			if ((le16toh(fs->e2fs->e2fs_state) & E2FS_ISCLEAN) == 0 ||
 			    (le16toh(fs->e2fs->e2fs_state) & E2FS_ERRORS)) {
 				if (mp->mnt_flag & MNT_FORCE) {
 					printf(
 "WARNING: %s was not properly dismounted\n", fs->e2fs_fsmnt);
 				} else {
 					printf(
 "WARNING: R/W mount of %s denied.  Filesystem is not clean - run fsck\n",
 					    fs->e2fs_fsmnt);
 					return (EPERM);
 				}
 			}
 			fs->e2fs->e2fs_state =
 			    htole16(le16toh(fs->e2fs->e2fs_state) & ~E2FS_ISCLEAN);
 			(void)ext2_cgupdate(ump, MNT_WAIT);
 			fs->e2fs_ronly = 0;
 			MNT_ILOCK(mp);
 			mp->mnt_flag &= ~MNT_RDONLY;
 			MNT_IUNLOCK(mp);
 		}
 		if (vfs_flagopt(opts, "export", NULL, 0)) {
 			/* Process export requests in vfs_mount.c. */
 			return (error);
 		}
 	}
 
 	/*
 	 * Not an update, or updating the name: look up the name
 	 * and verify that it refers to a sensible disk device.
 	 */
 	if (fspec == NULL)
 		return (EINVAL);
 	NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, fspec);
 	if ((error = namei(ndp)) != 0)
 		return (error);
 	NDFREE(ndp, NDF_ONLY_PNBUF);
 	devvp = ndp->ni_vp;
 
 	if (!vn_isdisk_error(devvp, &error)) {
 		vput(devvp);
 		return (error);
 	}
 
 	/*
 	 * If mount by non-root, then verify that user has necessary
 	 * permissions on the device.
 	 *
 	 * XXXRW: VOP_ACCESS() enough?
 	 */
 	accmode = VREAD;
 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
 		accmode |= VWRITE;
 	error = VOP_ACCESS(devvp, accmode, td->td_ucred, td);
 	if (error)
 		error = priv_check(td, PRIV_VFS_MOUNT_PERM);
 	if (error) {
 		vput(devvp);
 		return (error);
 	}
 
 	if ((mp->mnt_flag & MNT_UPDATE) == 0) {
 		error = ext2_mountfs(devvp, mp);
 	} else {
 		if (devvp != ump->um_devvp) {
 			vput(devvp);
 			return (EINVAL);	/* needs translation */
 		} else
 			vput(devvp);
 	}
 	if (error) {
 		vrele(devvp);
 		return (error);
 	}
 	ump = VFSTOEXT2(mp);
 	fs = ump->um_e2fs;
 
 	/*
 	 * Note that this strncpy() is ok because of a check at the start
 	 * of ext2_mount().
 	 */
 	strncpy(fs->e2fs_fsmnt, path, MAXMNTLEN);
 	fs->e2fs_fsmnt[MAXMNTLEN - 1] = '\0';
 	vfs_mountedfrom(mp, fspec);
 	return (0);
 }
 
 static int
 ext2_check_sb_compat(struct ext2fs *es, struct cdev *dev, int ronly)
 {
 	uint32_t i, mask;
 
 	if (le16toh(es->e2fs_magic) != E2FS_MAGIC) {
 		printf("ext2fs: %s: wrong magic number %#x (expected %#x)\n",
 		    devtoname(dev), le16toh(es->e2fs_magic), E2FS_MAGIC);
 		return (1);
 	}
 	if (le32toh(es->e2fs_rev) > E2FS_REV0) {
 		mask = le32toh(es->e2fs_features_incompat) & ~(EXT2F_INCOMPAT_SUPP);
 		if (mask) {
 			printf("WARNING: mount of %s denied due to "
 			    "unsupported optional features:\n", devtoname(dev));
 			for (i = 0;
 			    i < sizeof(incompat)/sizeof(struct ext2_feature);
 			    i++)
 				if (mask & incompat[i].mask)
 					printf("%s ", incompat[i].name);
 			printf("\n");
 			return (1);
 		}
 		mask = le32toh(es->e2fs_features_rocompat) & ~EXT2F_ROCOMPAT_SUPP;
 		if (!ronly && mask) {
 			printf("WARNING: R/W mount of %s denied due to "
 			    "unsupported optional features:\n", devtoname(dev));
 			for (i = 0;
 			    i < sizeof(ro_compat)/sizeof(struct ext2_feature);
 			    i++)
 				if (mask & ro_compat[i].mask)
 					printf("%s ", ro_compat[i].name);
 			printf("\n");
 			return (1);
 		}
 	}
 	return (0);
 }
 
 static e4fs_daddr_t
 ext2_cg_location(struct m_ext2fs *fs, int number)
 {
 	int cg, descpb, logical_sb, has_super = 0;
 
 	/*
 	 * Adjust logical superblock block number.
 	 * Godmar thinks: if the blocksize is greater than 1024, then
 	 * the superblock is logically part of block zero.
 	 */
 	logical_sb = fs->e2fs_bsize > SBSIZE ? 0 : 1;
 
 	if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_META_BG) ||
 	    number < le32toh(fs->e2fs->e3fs_first_meta_bg))
 		return (logical_sb + number + 1);
 
 	if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT))
 		descpb = fs->e2fs_bsize / sizeof(struct ext2_gd);
 	else
 		descpb = fs->e2fs_bsize / E2FS_REV0_GD_SIZE;
 
 	cg = descpb * number;
 
 	if (ext2_cg_has_sb(fs, cg))
 		has_super = 1;
 
 	return (has_super + cg * (e4fs_daddr_t)EXT2_BLOCKS_PER_GROUP(fs) +
 	    le32toh(fs->e2fs->e2fs_first_dblock));
 }
 
 static int
 ext2_cg_validate(struct m_ext2fs *fs)
 {
 	uint64_t b_bitmap;
 	uint64_t i_bitmap;
 	uint64_t i_tables;
 	uint64_t first_block, last_block, last_cg_block;
 	struct ext2_gd *gd;
 	unsigned int i, cg_count;
 
 	first_block = le32toh(fs->e2fs->e2fs_first_dblock);
 	last_cg_block = ext2_cg_number_gdb(fs, 0);
 	cg_count = fs->e2fs_gcount;
 
 	for (i = 0; i < fs->e2fs_gcount; i++) {
 		gd = &fs->e2fs_gd[i];
 
 		if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FLEX_BG) ||
 		    i == fs->e2fs_gcount - 1) {
 			last_block = fs->e2fs_bcount - 1;
 		} else {
 			last_block = first_block +
 			    (EXT2_BLOCKS_PER_GROUP(fs) - 1);
 		}
 
 		if ((cg_count == fs->e2fs_gcount) &&
 		    !(le16toh(gd->ext4bgd_flags) & EXT2_BG_INODE_ZEROED))
 			cg_count = i;
 
 		b_bitmap = e2fs_gd_get_b_bitmap(gd);
 		if (b_bitmap == 0) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "block bitmap is zero", i);
 			return (EINVAL);
 		}
 		if (b_bitmap <= last_cg_block) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "block bitmap overlaps gds", i);
 			return (EINVAL);
 		}
 		if (b_bitmap < first_block || b_bitmap > last_block) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "block bitmap not in group", i);
 			return (EINVAL);
 		}
 
 		i_bitmap = e2fs_gd_get_i_bitmap(gd);
 		if (i_bitmap == 0) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "inode bitmap is zero", i);
 			return (EINVAL);
 		}
 		if (i_bitmap <= last_cg_block) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "inode bitmap overlaps gds", i);
 			return (EINVAL);
 		}
 		if (i_bitmap < first_block || i_bitmap > last_block) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "inode bitmap not in group blk", i);
 			return (EINVAL);
 		}
 
 		i_tables = e2fs_gd_get_i_tables(gd);
 		if (i_tables == 0) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "inode table is zero", i);
 			return (EINVAL);
 		}
 		if (i_tables <= last_cg_block) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "inode tables overlaps gds", i);
 			return (EINVAL);
 		}
 		if (i_tables < first_block ||
 		    i_tables + fs->e2fs_itpg - 1 > last_block) {
 			SDT_PROBE2(ext2fs, , vfsops, ext2_cg_validate_error,
 			    "inode tables not in group blk", i);
 			return (EINVAL);
 		}
 
 		if (!EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_FLEX_BG))
 			first_block += EXT2_BLOCKS_PER_GROUP(fs);
 	}
 
 	return (0);
 }
 
 /*
  * This computes the fields of the m_ext2fs structure from the
  * data in the ext2fs structure read in.
  */
 static int
 ext2_compute_sb_data(struct vnode *devvp, struct ext2fs *es,
     struct m_ext2fs *fs)
 {
 	struct buf *bp;
 	uint32_t e2fs_descpb, e2fs_gdbcount_alloc;
 	int i, j;
 	int g_count = 0;
 	int error;
 
-	/* Check if first dblock is valid */
-	if (fs->e2fs->e2fs_bcount >= 1024 && fs->e2fs->e2fs_first_dblock) {
-		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
-		    "first dblock is invalid");
-		return (EINVAL);
-	}
-
 	/* Check checksum features */
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) &&
 	    EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "incorrect checksum features combination");
 		return (EINVAL);
 	}
 
 	/* Precompute checksum seed for all metadata */
 	ext2_sb_csum_set_seed(fs);
 
 	/* Verify sb csum if possible */
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
 		error = ext2_sb_csum_verify(fs);
 		if (error) {
 			return (error);
 		}
 	}
 
 	/* Check for block size = 1K|2K|4K */
 	if (le32toh(es->e2fs_log_bsize) > 2) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "bad block size");
 		return (EINVAL);
 	}
 
 	fs->e2fs_bshift = EXT2_MIN_BLOCK_LOG_SIZE + le32toh(es->e2fs_log_bsize);
 	fs->e2fs_bsize = 1U << fs->e2fs_bshift;
 	fs->e2fs_fsbtodb = le32toh(es->e2fs_log_bsize) + 1;
 	fs->e2fs_qbmask = fs->e2fs_bsize - 1;
 
 	/* Check for fragment size */
 	if (le32toh(es->e2fs_log_fsize) >
 	    (EXT2_MAX_FRAG_LOG_SIZE - EXT2_MIN_BLOCK_LOG_SIZE)) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "invalid log cluster size");
 		return (EINVAL);
 	}
 
 	fs->e2fs_fsize = EXT2_MIN_FRAG_SIZE << le32toh(es->e2fs_log_fsize);
 	if (fs->e2fs_fsize != fs->e2fs_bsize) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "fragment size != block size");
 		return (EINVAL);
 	}
 
 	fs->e2fs_fpb = fs->e2fs_bsize / fs->e2fs_fsize;
 
 	/* Check reserved gdt blocks for future filesystem expansion */
 	if (le16toh(es->e2fs_reserved_ngdb) > (fs->e2fs_bsize / 4)) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "number of reserved GDT blocks too large");
 		return (EINVAL);
 	}
 
 	if (le32toh(es->e2fs_rev) == E2FS_REV0) {
 		fs->e2fs_isize = E2FS_REV0_INODE_SIZE;
 	} else {
 		fs->e2fs_isize = le16toh(es->e2fs_inode_size);
 
 		/*
 		 * Check first ino.
 		 */
 		if (le32toh(es->e2fs_first_ino) < EXT2_FIRSTINO) {
 			SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 			    "invalid first ino");
 			return (EINVAL);
 		}
 
 		/*
 		 * Simple sanity check for superblock inode size value.
 		 */
 		if (EXT2_INODE_SIZE(fs) < E2FS_REV0_INODE_SIZE ||
 		    EXT2_INODE_SIZE(fs) > fs->e2fs_bsize ||
 		    (fs->e2fs_isize & (fs->e2fs_isize - 1)) != 0) {
 			SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 			    "invalid inode size");
 			return (EINVAL);
 		}
 	}
 
 	/* Check group descriptors */
 	if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT) &&
 	    le16toh(es->e3fs_desc_size) != E2FS_64BIT_GD_SIZE) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "unsupported 64bit descriptor size");
 		return (EINVAL);
 	}
 
 	fs->e2fs_bpg = le32toh(es->e2fs_bpg);
 	fs->e2fs_fpg = le32toh(es->e2fs_fpg);
 	if (fs->e2fs_bpg == 0 || fs->e2fs_fpg == 0) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "zero blocks/fragments per group");
 		return (EINVAL);
 	} else if (fs->e2fs_bpg != fs->e2fs_fpg) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "blocks per group not equal fragments per group");
 		return (EINVAL);
 	}
 
 	if (fs->e2fs_bpg != fs->e2fs_bsize * 8) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "non-standard group size unsupported");
 		return (EINVAL);
 	}
 
 	fs->e2fs_ipb = fs->e2fs_bsize / EXT2_INODE_SIZE(fs);
 	if (fs->e2fs_ipb == 0 ||
 	    fs->e2fs_ipb > fs->e2fs_bsize / E2FS_REV0_INODE_SIZE) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "bad inodes per block size");
 		return (EINVAL);
 	}
 
 	fs->e2fs_ipg = le32toh(es->e2fs_ipg);
 	if (fs->e2fs_ipg < fs->e2fs_ipb || fs->e2fs_ipg >  fs->e2fs_bsize * 8) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "invalid inodes per group");
 		return (EINVAL);
 	}
 
 	fs->e2fs_itpg = fs->e2fs_ipg / fs->e2fs_ipb;
 
 	fs->e2fs_bcount = le32toh(es->e2fs_bcount);
 	fs->e2fs_rbcount = le32toh(es->e2fs_rbcount);
 	fs->e2fs_fbcount = le32toh(es->e2fs_fbcount);
 	if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT)) {
 		fs->e2fs_bcount |= (uint64_t)(le32toh(es->e4fs_bcount_hi)) << 32;
 		fs->e2fs_rbcount |= (uint64_t)(le32toh(es->e4fs_rbcount_hi)) << 32;
 		fs->e2fs_fbcount |= (uint64_t)(le32toh(es->e4fs_fbcount_hi)) << 32;
 	}
 	if (fs->e2fs_rbcount > fs->e2fs_bcount ||
 	    fs->e2fs_fbcount > fs->e2fs_bcount) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "invalid block count");
 		return (EINVAL);
 	}
 
 	fs->e2fs_ficount = le32toh(es->e2fs_ficount);
 	if (fs->e2fs_ficount > le32toh(es->e2fs_icount)) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "invalid number of free inodes");
 		return (EINVAL);
 	}
 
 	if (le32toh(es->e2fs_first_dblock) != (fs->e2fs_bsize > 1024 ? 0 : 1) ||
 	    le32toh(es->e2fs_first_dblock) >= fs->e2fs_bcount) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "first data block out of range");
 		return (EINVAL);
 	}
 
 	fs->e2fs_gcount = howmany(fs->e2fs_bcount -
 	    le32toh(es->e2fs_first_dblock), EXT2_BLOCKS_PER_GROUP(fs));
 	if (fs->e2fs_gcount > ((uint64_t)1 << 32) - EXT2_DESCS_PER_BLOCK(fs)) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "groups count too large");
 		return (EINVAL);
 	}
 
 	/* Check for extra isize in big inodes. */
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_EXTRA_ISIZE) &&
 	    EXT2_INODE_SIZE(fs) < sizeof(struct ext2fs_dinode)) {
 		SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
 		    "no space for extra inode timestamps");
 		return (EINVAL);
 	}
 
 	/* s_resuid / s_resgid ? */
 
 	if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT)) {
 		e2fs_descpb = fs->e2fs_bsize / E2FS_64BIT_GD_SIZE;
 		e2fs_gdbcount_alloc = howmany(fs->e2fs_gcount, e2fs_descpb);
 	} else {
 		e2fs_descpb = fs->e2fs_bsize / E2FS_REV0_GD_SIZE;
 		e2fs_gdbcount_alloc = howmany(fs->e2fs_gcount,
 		    fs->e2fs_bsize / sizeof(struct ext2_gd));
 	}
 	fs->e2fs_gdbcount = howmany(fs->e2fs_gcount, e2fs_descpb);
 	fs->e2fs_gd = malloc(e2fs_gdbcount_alloc * fs->e2fs_bsize,
 	    M_EXT2MNT, M_WAITOK | M_ZERO);
 	fs->e2fs_contigdirs = malloc(fs->e2fs_gcount *
 	    sizeof(*fs->e2fs_contigdirs), M_EXT2MNT, M_WAITOK | M_ZERO);
 
 	for (i = 0; i < fs->e2fs_gdbcount; i++) {
 		error = bread(devvp,
 		    fsbtodb(fs, ext2_cg_location(fs, i)),
 		    fs->e2fs_bsize, NOCRED, &bp);
 		if (error) {
 			/*
 			 * fs->e2fs_gd and fs->e2fs_contigdirs
 			 * will be freed later by the caller,
 			 * because this function could be called from
 			 * MNT_UPDATE path.
 			 */
 			return (error);
 		}
 		if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT)) {
 			memcpy(&fs->e2fs_gd[
 			    i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
 			    bp->b_data, fs->e2fs_bsize);
 		} else {
 			for (j = 0; j < e2fs_descpb &&
 			    g_count < fs->e2fs_gcount; j++, g_count++)
 				memcpy(&fs->e2fs_gd[g_count],
 				    bp->b_data + j * E2FS_REV0_GD_SIZE,
 				    E2FS_REV0_GD_SIZE);
 		}
 		brelse(bp);
 		bp = NULL;
 	}
 
 	/* Validate cgs consistency */
 	error = ext2_cg_validate(fs);
 	if (error)
 		return (error);
 
 	/* Verfy cgs csum */
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) ||
 	    EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
 		error = ext2_gd_csum_verify(fs, devvp->v_rdev);
 		if (error)
 			return (error);
 	}
 	/* Initialization for the ext2 Orlov allocator variant. */
 	fs->e2fs_total_dir = 0;
 	for (i = 0; i < fs->e2fs_gcount; i++)
 		fs->e2fs_total_dir += e2fs_gd_get_ndirs(&fs->e2fs_gd[i]);
 
 	if (le32toh(es->e2fs_rev) == E2FS_REV0 ||
 	    !EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_LARGEFILE))
 		fs->e2fs_maxfilesize = 0x7fffffff;
 	else {
 		fs->e2fs_maxfilesize = 0xffffffffffff;
 		if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_HUGE_FILE))
 			fs->e2fs_maxfilesize = 0x7fffffffffffffff;
 	}
 	if (le32toh(es->e4fs_flags) & E2FS_UNSIGNED_HASH) {
 		fs->e2fs_uhash = 3;
 	} else if ((le32toh(es->e4fs_flags) & E2FS_SIGNED_HASH) == 0) {
 #ifdef __CHAR_UNSIGNED__
 		es->e4fs_flags = htole32(le32toh(es->e4fs_flags) | E2FS_UNSIGNED_HASH);
 		fs->e2fs_uhash = 3;
 #else
 		es->e4fs_flags = htole32(le32toh(es->e4fs_flags) | E2FS_SIGNED_HASH);
 #endif
 	}
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM))
 		error = ext2_sb_csum_verify(fs);
 
 	return (error);
 }
 
 /*
  * Reload all incore data for a filesystem (used after running fsck on
  * the root filesystem and finding things to fix). The filesystem must
  * be mounted read-only.
  *
  * Things to do to update the mount:
  *	1) invalidate all cached meta-data.
  *	2) re-read superblock from disk.
  *	3) invalidate all cluster summary information.
  *	4) invalidate all inactive vnodes.
  *	5) invalidate all cached file data.
  *	6) re-read inode data for all active vnodes.
  * XXX we are missing some steps, in particular # 3, this has to be reviewed.
  */
 static int
 ext2_reload(struct mount *mp, struct thread *td)
 {
 	struct vnode *vp, *mvp, *devvp;
 	struct inode *ip;
 	struct buf *bp;
 	struct ext2fs *es;
 	struct m_ext2fs *fs;
 	struct csum *sump;
 	int error, i;
 	int32_t *lp;
 
 	if ((mp->mnt_flag & MNT_RDONLY) == 0)
 		return (EINVAL);
 	/*
 	 * Step 1: invalidate all cached meta-data.
 	 */
 	devvp = VFSTOEXT2(mp)->um_devvp;
 	vn_lock(devvp, LK_EXCLUSIVE | LK_RETRY);
 	if (vinvalbuf(devvp, 0, 0, 0) != 0)
 		panic("ext2_reload: dirty1");
 	VOP_UNLOCK(devvp);
 
 	/*
 	 * Step 2: re-read superblock from disk.
 	 * constants have been adjusted for ext2
 	 */
 	if ((error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp)) != 0)
 		return (error);
 	es = (struct ext2fs *)bp->b_data;
 	if (ext2_check_sb_compat(es, devvp->v_rdev, 0) != 0) {
 		brelse(bp);
 		return (EIO);		/* XXX needs translation */
 	}
 	fs = VFSTOEXT2(mp)->um_e2fs;
 	bcopy(bp->b_data, fs->e2fs, sizeof(struct ext2fs));
 
 	if ((error = ext2_compute_sb_data(devvp, es, fs)) != 0) {
 		brelse(bp);
 		return (error);
 	}
 #ifdef UNKLAR
 	if (fs->fs_sbsize < SBSIZE)
 		bp->b_flags |= B_INVAL;
 #endif
 	brelse(bp);
 
 	/*
 	 * Step 3: invalidate all cluster summary information.
 	 */
 	if (fs->e2fs_contigsumsize > 0) {
 		lp = fs->e2fs_maxcluster;
 		sump = fs->e2fs_clustersum;
 		for (i = 0; i < fs->e2fs_gcount; i++, sump++) {
 			*lp++ = fs->e2fs_contigsumsize;
 			sump->cs_init = 0;
 			bzero(sump->cs_sum, fs->e2fs_contigsumsize + 1);
 		}
 	}
 
 loop:
 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
 		/*
 		 * Step 4: invalidate all cached file data.
 		 */
 		if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK)) {
 			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 			goto loop;
 		}
 		if (vinvalbuf(vp, 0, 0, 0))
 			panic("ext2_reload: dirty2");
 
 		/*
 		 * Step 5: re-read inode data for all active vnodes.
 		 */
 		ip = VTOI(vp);
 		error = bread(devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
 		    (int)fs->e2fs_bsize, NOCRED, &bp);
 		if (error) {
 			VOP_UNLOCK(vp);
 			vrele(vp);
 			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 			return (error);
 		}
 
 		error = ext2_ei2i((struct ext2fs_dinode *)((char *)bp->b_data +
 		    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ip->i_number)), ip);
 
 		brelse(bp);
 		VOP_UNLOCK(vp);
 		vrele(vp);
 
 		if (error) {
 			MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 			return (error);
 		}
 	}
 	return (0);
 }
 
 /*
  * Common code for mount and mountroot.
  */
 static int
 ext2_mountfs(struct vnode *devvp, struct mount *mp)
 {
 	struct ext2mount *ump;
 	struct buf *bp;
 	struct m_ext2fs *fs;
 	struct ext2fs *es;
 	struct cdev *dev = devvp->v_rdev;
 	struct g_consumer *cp;
 	struct bufobj *bo;
 	struct csum *sump;
 	int error;
 	int ronly;
 	int i;
 	u_long size;
 	int32_t *lp;
 	int32_t e2fs_maxcontig;
 
 	ronly = vfs_flagopt(mp->mnt_optnew, "ro", NULL, 0);
 	/* XXX: use VOP_ACESS to check FS perms */
 	g_topology_lock();
 	error = g_vfs_open(devvp, &cp, "ext2fs", ronly ? 0 : 1);
 	g_topology_unlock();
 	VOP_UNLOCK(devvp);
 	if (error)
 		return (error);
 
 	/* XXX: should we check for some sectorsize or 512 instead? */
 	if (((SBSIZE % cp->provider->sectorsize) != 0) ||
 	    (SBSIZE < cp->provider->sectorsize)) {
 		g_topology_lock();
 		g_vfs_close(cp);
 		g_topology_unlock();
 		return (EINVAL);
 	}
 
 	bo = &devvp->v_bufobj;
 	bo->bo_private = cp;
 	bo->bo_ops = g_vfs_bufops;
 	if (devvp->v_rdev->si_iosize_max != 0)
 		mp->mnt_iosize_max = devvp->v_rdev->si_iosize_max;
 	if (mp->mnt_iosize_max > maxphys)
 		mp->mnt_iosize_max = maxphys;
 
 	bp = NULL;
 	ump = NULL;
 	if ((error = bread(devvp, SBLOCK, SBSIZE, NOCRED, &bp)) != 0)
 		goto out;
 	es = (struct ext2fs *)bp->b_data;
 	if (ext2_check_sb_compat(es, dev, ronly) != 0) {
 		error = EINVAL;		/* XXX needs translation */
 		goto out;
 	}
 	if ((le16toh(es->e2fs_state) & E2FS_ISCLEAN) == 0 ||
 	    (le16toh(es->e2fs_state) & E2FS_ERRORS)) {
 		if (ronly || (mp->mnt_flag & MNT_FORCE)) {
 			printf(
 "WARNING: Filesystem was not properly dismounted\n");
 		} else {
 			printf(
 "WARNING: R/W mount denied.  Filesystem is not clean - run fsck\n");
 			error = EPERM;
 			goto out;
 		}
 	}
 	ump = malloc(sizeof(*ump), M_EXT2MNT, M_WAITOK | M_ZERO);
 
 	/*
 	 * I don't know whether this is the right strategy. Note that
 	 * we dynamically allocate both an m_ext2fs and an ext2fs
 	 * while Linux keeps the super block in a locked buffer.
 	 */
 	ump->um_e2fs = malloc(sizeof(struct m_ext2fs),
 	    M_EXT2MNT, M_WAITOK | M_ZERO);
 	ump->um_e2fs->e2fs = malloc(sizeof(struct ext2fs),
 	    M_EXT2MNT, M_WAITOK);
 	mtx_init(EXT2_MTX(ump), "EXT2FS", "EXT2FS Lock", MTX_DEF);
 	bcopy(es, ump->um_e2fs->e2fs, (u_int)sizeof(struct ext2fs));
 	if ((error = ext2_compute_sb_data(devvp, ump->um_e2fs->e2fs, ump->um_e2fs)))
 		goto out;
 
 	/*
 	 * Calculate the maximum contiguous blocks and size of cluster summary
 	 * array.  In FFS this is done by newfs; however, the superblock
 	 * in ext2fs doesn't have these variables, so we can calculate
 	 * them here.
 	 */
 	e2fs_maxcontig = MAX(1, maxphys / ump->um_e2fs->e2fs_bsize);
 	ump->um_e2fs->e2fs_contigsumsize = MIN(e2fs_maxcontig, EXT2_MAXCONTIG);
 	ump->um_e2fs->e2fs_maxsymlinklen = EXT2_MAXSYMLINKLEN;
 	if (ump->um_e2fs->e2fs_contigsumsize > 0) {
 		size = ump->um_e2fs->e2fs_gcount * sizeof(int32_t);
 		ump->um_e2fs->e2fs_maxcluster = malloc(size, M_EXT2MNT, M_WAITOK);
 		size = ump->um_e2fs->e2fs_gcount * sizeof(struct csum);
 		ump->um_e2fs->e2fs_clustersum = malloc(size, M_EXT2MNT, M_WAITOK);
 		lp = ump->um_e2fs->e2fs_maxcluster;
 		sump = ump->um_e2fs->e2fs_clustersum;
 		for (i = 0; i < ump->um_e2fs->e2fs_gcount; i++, sump++) {
 			*lp++ = ump->um_e2fs->e2fs_contigsumsize;
 			sump->cs_init = 0;
 			sump->cs_sum = malloc((ump->um_e2fs->e2fs_contigsumsize + 1) *
 			    sizeof(int32_t), M_EXT2MNT, M_WAITOK | M_ZERO);
 		}
 	}
 
 	brelse(bp);
 	bp = NULL;
 	fs = ump->um_e2fs;
 	fs->e2fs_ronly = ronly;	/* ronly is set according to mnt_flags */
 
 	/*
 	 * If the fs is not mounted read-only, make sure the super block is
 	 * always written back on a sync().
 	 */
 	fs->e2fs_wasvalid = le16toh(fs->e2fs->e2fs_state) & E2FS_ISCLEAN ? 1 : 0;
 	if (ronly == 0) {
 		fs->e2fs_fmod = 1;	/* mark it modified and set fs invalid */
 		fs->e2fs->e2fs_state =
 		    htole16(le16toh(fs->e2fs->e2fs_state) & ~E2FS_ISCLEAN);
 	}
 	mp->mnt_data = ump;
 	mp->mnt_stat.f_fsid.val[0] = dev2udev(dev);
 	mp->mnt_stat.f_fsid.val[1] = mp->mnt_vfc->vfc_typenum;
 	MNT_ILOCK(mp);
 	mp->mnt_flag |= MNT_LOCAL;
 	MNT_IUNLOCK(mp);
 	ump->um_mountp = mp;
 	ump->um_dev = dev;
 	ump->um_devvp = devvp;
 	ump->um_bo = &devvp->v_bufobj;
 	ump->um_cp = cp;
 
 	/*
 	 * Setting those two parameters allowed us to use
 	 * ufs_bmap w/o changse!
 	 */
 	ump->um_nindir = EXT2_ADDR_PER_BLOCK(fs);
 	ump->um_bptrtodb = le32toh(fs->e2fs->e2fs_log_bsize) + 1;
 	ump->um_seqinc = EXT2_FRAGS_PER_BLOCK(fs);
 	if (ronly == 0)
 		ext2_sbupdate(ump, MNT_WAIT);
 	/*
 	 * Initialize filesystem stat information in mount struct.
 	 */
 	MNT_ILOCK(mp);
 	mp->mnt_kern_flag |= MNTK_LOOKUP_SHARED | MNTK_EXTENDED_SHARED |
 	    MNTK_USES_BCACHE;
 	MNT_IUNLOCK(mp);
 	return (0);
 out:
 	if (bp)
 		brelse(bp);
 	if (cp != NULL) {
 		g_topology_lock();
 		g_vfs_close(cp);
 		g_topology_unlock();
 	}
 	if (ump) {
 		mtx_destroy(EXT2_MTX(ump));
 		free(ump->um_e2fs->e2fs_gd, M_EXT2MNT);
 		free(ump->um_e2fs->e2fs_contigdirs, M_EXT2MNT);
 		free(ump->um_e2fs->e2fs, M_EXT2MNT);
 		free(ump->um_e2fs, M_EXT2MNT);
 		free(ump, M_EXT2MNT);
 		mp->mnt_data = NULL;
 	}
 	return (error);
 }
 
 /*
  * Unmount system call.
  */
 static int
 ext2_unmount(struct mount *mp, int mntflags)
 {
 	struct ext2mount *ump;
 	struct m_ext2fs *fs;
 	struct csum *sump;
 	int error, flags, i, ronly;
 
 	flags = 0;
 	if (mntflags & MNT_FORCE) {
 		if (mp->mnt_flag & MNT_ROOTFS)
 			return (EINVAL);
 		flags |= FORCECLOSE;
 	}
 	if ((error = ext2_flushfiles(mp, flags, curthread)) != 0)
 		return (error);
 	ump = VFSTOEXT2(mp);
 	fs = ump->um_e2fs;
 	ronly = fs->e2fs_ronly;
 	if (ronly == 0 && ext2_cgupdate(ump, MNT_WAIT) == 0) {
 		if (fs->e2fs_wasvalid)
 			fs->e2fs->e2fs_state =
 			    htole16(le16toh(fs->e2fs->e2fs_state) | E2FS_ISCLEAN);
 		ext2_sbupdate(ump, MNT_WAIT);
 	}
 
 	g_topology_lock();
 	g_vfs_close(ump->um_cp);
 	g_topology_unlock();
 	vrele(ump->um_devvp);
 	sump = fs->e2fs_clustersum;
 	for (i = 0; i < fs->e2fs_gcount; i++, sump++)
 		free(sump->cs_sum, M_EXT2MNT);
 	free(fs->e2fs_clustersum, M_EXT2MNT);
 	free(fs->e2fs_maxcluster, M_EXT2MNT);
 	free(fs->e2fs_gd, M_EXT2MNT);
 	free(fs->e2fs_contigdirs, M_EXT2MNT);
 	free(fs->e2fs, M_EXT2MNT);
 	free(fs, M_EXT2MNT);
 	free(ump, M_EXT2MNT);
 	mp->mnt_data = NULL;
 	MNT_ILOCK(mp);
 	mp->mnt_flag &= ~MNT_LOCAL;
 	MNT_IUNLOCK(mp);
 	return (error);
 }
 
 /*
  * Flush out all the files in a filesystem.
  */
 static int
 ext2_flushfiles(struct mount *mp, int flags, struct thread *td)
 {
 	int error;
 
 	error = vflush(mp, 0, flags, td);
 	return (error);
 }
 
 /*
  * Get filesystem statistics.
  */
 int
 ext2_statfs(struct mount *mp, struct statfs *sbp)
 {
 	struct ext2mount *ump;
 	struct m_ext2fs *fs;
 	uint32_t overhead, overhead_per_group, ngdb;
 	int i, ngroups;
 
 	ump = VFSTOEXT2(mp);
 	fs = ump->um_e2fs;
 	if (le16toh(fs->e2fs->e2fs_magic) != E2FS_MAGIC)
 		panic("ext2_statfs");
 
 	/*
 	 * Compute the overhead (FS structures)
 	 */
 	overhead_per_group =
 	    1 /* block bitmap */ +
 	    1 /* inode bitmap */ +
 	    fs->e2fs_itpg;
 	overhead = le32toh(fs->e2fs->e2fs_first_dblock) +
 	    fs->e2fs_gcount * overhead_per_group;
 	if (le32toh(fs->e2fs->e2fs_rev) > E2FS_REV0 &&
 	    le32toh(fs->e2fs->e2fs_features_rocompat) & EXT2F_ROCOMPAT_SPARSESUPER) {
 		for (i = 0, ngroups = 0; i < fs->e2fs_gcount; i++) {
 			if (ext2_cg_has_sb(fs, i))
 				ngroups++;
 		}
 	} else {
 		ngroups = fs->e2fs_gcount;
 	}
 	ngdb = fs->e2fs_gdbcount;
 	if (le32toh(fs->e2fs->e2fs_rev) > E2FS_REV0 &&
 	    le32toh(fs->e2fs->e2fs_features_compat) & EXT2F_COMPAT_RESIZE)
 		ngdb += le16toh(fs->e2fs->e2fs_reserved_ngdb);
 	overhead += ngroups * (1 /* superblock */ + ngdb);
 
 	sbp->f_bsize = EXT2_FRAG_SIZE(fs);
 	sbp->f_iosize = EXT2_BLOCK_SIZE(fs);
 	sbp->f_blocks = fs->e2fs_bcount - overhead;
 	sbp->f_bfree = fs->e2fs_fbcount;
 	sbp->f_bavail = sbp->f_bfree - fs->e2fs_rbcount;
 	sbp->f_files = le32toh(fs->e2fs->e2fs_icount);
 	sbp->f_ffree = fs->e2fs_ficount;
 	return (0);
 }
 
 /*
  * Go through the disk queues to initiate sandbagged IO;
  * go through the inodes to write those that have been modified;
  * initiate the writing of the super block if it has been modified.
  *
  * Note: we are always called with the filesystem marked `MPBUSY'.
  */
 static int
 ext2_sync(struct mount *mp, int waitfor)
 {
 	struct vnode *mvp, *vp;
 	struct thread *td;
 	struct inode *ip;
 	struct ext2mount *ump = VFSTOEXT2(mp);
 	struct m_ext2fs *fs;
 	int error, allerror = 0;
 
 	td = curthread;
 	fs = ump->um_e2fs;
 	if (fs->e2fs_fmod != 0 && fs->e2fs_ronly != 0) {		/* XXX */
 		panic("ext2_sync: rofs mod fs=%s", fs->e2fs_fsmnt);
 	}
 
 	/*
 	 * Write back each (modified) inode.
 	 */
 loop:
 	MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
 		if (vp->v_type == VNON) {
 			VI_UNLOCK(vp);
 			continue;
 		}
 		ip = VTOI(vp);
 		if ((ip->i_flag &
 		    (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE)) == 0 &&
 		    (vp->v_bufobj.bo_dirty.bv_cnt == 0 ||
 		    waitfor == MNT_LAZY)) {
 			VI_UNLOCK(vp);
 			continue;
 		}
 		error = vget(vp, LK_EXCLUSIVE | LK_NOWAIT | LK_INTERLOCK);
 		if (error) {
 			if (error == ENOENT) {
 				MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp);
 				goto loop;
 			}
 			continue;
 		}
 		if ((error = VOP_FSYNC(vp, waitfor, td)) != 0)
 			allerror = error;
 		VOP_UNLOCK(vp);
 		vrele(vp);
 	}
 
 	/*
 	 * Force stale filesystem control information to be flushed.
 	 */
 	if (waitfor != MNT_LAZY) {
 		vn_lock(ump->um_devvp, LK_EXCLUSIVE | LK_RETRY);
 		if ((error = VOP_FSYNC(ump->um_devvp, waitfor, td)) != 0)
 			allerror = error;
 		VOP_UNLOCK(ump->um_devvp);
 	}
 
 	/*
 	 * Write back modified superblock.
 	 */
 	if (fs->e2fs_fmod != 0) {
 		fs->e2fs_fmod = 0;
 		fs->e2fs->e2fs_wtime = htole32(time_second);
 		if ((error = ext2_cgupdate(ump, waitfor)) != 0)
 			allerror = error;
 	}
 	return (allerror);
 }
 
 /*
  * Look up an EXT2FS dinode number to find its incore vnode, otherwise read it
  * in from disk.  If it is in core, wait for the lock bit to clear, then
  * return the inode locked.  Detection and handling of mount points must be
  * done by the calling routine.
  */
 static int
 ext2_vget(struct mount *mp, ino_t ino, int flags, struct vnode **vpp)
 {
 	struct m_ext2fs *fs;
 	struct inode *ip;
 	struct ext2mount *ump;
 	struct buf *bp;
 	struct vnode *vp;
 	struct thread *td;
 	unsigned int i, used_blocks;
 	int error;
 
 	td = curthread;
 	error = vfs_hash_get(mp, ino, flags, td, vpp, NULL, NULL);
 	if (error || *vpp != NULL)
 		return (error);
 
 	ump = VFSTOEXT2(mp);
 	ip = malloc(sizeof(struct inode), M_EXT2NODE, M_WAITOK | M_ZERO);
 
 	/* Allocate a new vnode/inode. */
 	if ((error = getnewvnode("ext2fs", mp, &ext2_vnodeops, &vp)) != 0) {
 		*vpp = NULL;
 		free(ip, M_EXT2NODE);
 		return (error);
 	}
 	vp->v_data = ip;
 	ip->i_vnode = vp;
 	ip->i_e2fs = fs = ump->um_e2fs;
 	ip->i_ump = ump;
 	ip->i_number = ino;
 	cluster_init_vn(&ip->i_clusterw);
 
 	lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL);
 	error = insmntque(vp, mp);
 	if (error != 0) {
 		free(ip, M_EXT2NODE);
 		*vpp = NULL;
 		return (error);
 	}
 	error = vfs_hash_insert(vp, ino, flags, td, vpp, NULL, NULL);
 	if (error || *vpp != NULL)
 		return (error);
 
 	/* Read in the disk contents for the inode, copy into the inode. */
 	if ((error = bread(ump->um_devvp, fsbtodb(fs, ino_to_fsba(fs, ino)),
 	    (int)fs->e2fs_bsize, NOCRED, &bp)) != 0) {
 		/*
 		 * The inode does not contain anything useful, so it would
 		 * be misleading to leave it on its hash chain. With mode
 		 * still zero, it will be unlinked and returned to the free
 		 * list by vput().
 		 */
 		brelse(bp);
 		vput(vp);
 		*vpp = NULL;
 		return (error);
 	}
 	/* convert ext2 inode to dinode */
 	error = ext2_ei2i((struct ext2fs_dinode *)((char *)bp->b_data +
 	    EXT2_INODE_SIZE(fs) * ino_to_fsbo(fs, ino)), ip);
 	if (error) {
 		brelse(bp);
 		vput(vp);
 		*vpp = NULL;
 		return (error);
 	}
 	ip->i_block_group = ino_to_cg(fs, ino);
 	ip->i_next_alloc_block = 0;
 	ip->i_next_alloc_goal = 0;
 
 	/*
 	 * Now we want to make sure that block pointers for unused
 	 * blocks are zeroed out - ext2_balloc depends on this
 	 * although for regular files and directories only
 	 *
 	 * If IN_E4EXTENTS is enabled, unused blocks are not zeroed
 	 * out because we could corrupt the extent tree.
 	 */
 	if (!(ip->i_flag & IN_E4EXTENTS) &&
 	    (S_ISDIR(ip->i_mode) || S_ISREG(ip->i_mode))) {
 		used_blocks = howmany(ip->i_size, fs->e2fs_bsize);
 		for (i = used_blocks; i < EXT2_NDIR_BLOCKS; i++)
 			ip->i_db[i] = 0;
 	}
 
 	bqrelse(bp);
 
 #ifdef EXT2FS_PRINT_EXTENTS
 	ext2_print_inode(ip);
 	error = ext4_ext_walk(ip);
 	if (error) {
 		vput(vp);
 		*vpp = NULL;
 		return (error);
 	}
 #endif
 
 	/*
 	 * Initialize the vnode from the inode, check for aliases.
 	 * Note that the underlying vnode may have changed.
 	 */
 	if ((error = ext2_vinit(mp, &ext2_fifoops, &vp)) != 0) {
 		vput(vp);
 		*vpp = NULL;
 		return (error);
 	}
 
 	/*
 	 * Finish inode initialization.
 	 */
 
 	*vpp = vp;
 	return (0);
 }
 
 /*
  * File handle to vnode
  *
  * Have to be really careful about stale file handles:
  * - check that the inode number is valid
  * - call ext2_vget() to get the locked inode
  * - check for an unallocated inode (i_mode == 0)
  * - check that the given client host has export rights and return
  *   those rights via. exflagsp and credanonp
  */
 static int
 ext2_fhtovp(struct mount *mp, struct fid *fhp, int flags, struct vnode **vpp)
 {
 	struct inode *ip;
 	struct ufid *ufhp;
 	struct vnode *nvp;
 	struct m_ext2fs *fs;
 	int error;
 
 	ufhp = (struct ufid *)fhp;
 	fs = VFSTOEXT2(mp)->um_e2fs;
 	if (ufhp->ufid_ino < EXT2_ROOTINO ||
 	    ufhp->ufid_ino > fs->e2fs_gcount * fs->e2fs_ipg)
 		return (ESTALE);
 
 	error = VFS_VGET(mp, ufhp->ufid_ino, LK_EXCLUSIVE, &nvp);
 	if (error) {
 		*vpp = NULLVP;
 		return (error);
 	}
 	ip = VTOI(nvp);
 	if (ip->i_mode == 0 ||
 	    ip->i_gen != ufhp->ufid_gen || ip->i_nlink <= 0) {
 		vput(nvp);
 		*vpp = NULLVP;
 		return (ESTALE);
 	}
 	*vpp = nvp;
 	vnode_create_vobject(*vpp, 0, curthread);
 	return (0);
 }
 
 /*
  * Write a superblock and associated information back to disk.
  */
 static int
 ext2_sbupdate(struct ext2mount *mp, int waitfor)
 {
 	struct m_ext2fs *fs = mp->um_e2fs;
 	struct ext2fs *es = fs->e2fs;
 	struct buf *bp;
 	int error = 0;
 
 	es->e2fs_bcount = htole32(fs->e2fs_bcount & 0xffffffff);
 	es->e2fs_rbcount = htole32(fs->e2fs_rbcount & 0xffffffff);
 	es->e2fs_fbcount = htole32(fs->e2fs_fbcount & 0xffffffff);
 	if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT)) {
 		es->e4fs_bcount_hi = htole32(fs->e2fs_bcount >> 32);
 		es->e4fs_rbcount_hi = htole32(fs->e2fs_rbcount >> 32);
 		es->e4fs_fbcount_hi = htole32(fs->e2fs_fbcount >> 32);
 	}
 
 	es->e2fs_ficount = htole32(fs->e2fs_ficount);
 
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM))
 		ext2_sb_csum_set(fs);
 
 	bp = getblk(mp->um_devvp, SBLOCK, SBSIZE, 0, 0, 0);
 	bcopy((caddr_t)es, bp->b_data, (u_int)sizeof(struct ext2fs));
 	if (waitfor == MNT_WAIT)
 		error = bwrite(bp);
 	else
 		bawrite(bp);
 
 	/*
 	 * The buffers for group descriptors, inode bitmaps and block bitmaps
 	 * are not busy at this point and are (hopefully) written by the
 	 * usual sync mechanism. No need to write them here.
 	 */
 	return (error);
 }
 int
 ext2_cgupdate(struct ext2mount *mp, int waitfor)
 {
 	struct m_ext2fs *fs = mp->um_e2fs;
 	struct buf *bp;
 	int i, j, g_count = 0, error = 0, allerror = 0;
 
 	allerror = ext2_sbupdate(mp, waitfor);
 
 	/* Update gd csums */
 	if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) ||
 	    EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM))
 		ext2_gd_csum_set(fs);
 
 	for (i = 0; i < fs->e2fs_gdbcount; i++) {
 		bp = getblk(mp->um_devvp, fsbtodb(fs,
 		    ext2_cg_location(fs, i)),
 		    fs->e2fs_bsize, 0, 0, 0);
 		if (EXT2_HAS_INCOMPAT_FEATURE(fs, EXT2F_INCOMPAT_64BIT)) {
 			memcpy(bp->b_data, &fs->e2fs_gd[
 			    i * fs->e2fs_bsize / sizeof(struct ext2_gd)],
 			    fs->e2fs_bsize);
 		} else {
 			for (j = 0; j < fs->e2fs_bsize / E2FS_REV0_GD_SIZE &&
 			    g_count < fs->e2fs_gcount; j++, g_count++)
 				memcpy(bp->b_data + j * E2FS_REV0_GD_SIZE,
 				    &fs->e2fs_gd[g_count], E2FS_REV0_GD_SIZE);
 		}
 		if (waitfor == MNT_WAIT)
 			error = bwrite(bp);
 		else
 			bawrite(bp);
 	}
 
 	if (!allerror && error)
 		allerror = error;
 	return (allerror);
 }
 
 /*
  * Return the root of a filesystem.
  */
 static int
 ext2_root(struct mount *mp, int flags, struct vnode **vpp)
 {
 	struct vnode *nvp;
 	int error;
 
 	error = VFS_VGET(mp, EXT2_ROOTINO, LK_EXCLUSIVE, &nvp);
 	if (error)
 		return (error);
 	*vpp = nvp;
 	return (0);
 }