diff --git a/sys/ufs/ffs/ffs_alloc.c b/sys/ufs/ffs/ffs_alloc.c
index c7a1e2dec15e..c895c8c7bf07 100644
--- a/sys/ufs/ffs/ffs_alloc.c
+++ b/sys/ufs/ffs/ffs_alloc.c
@@ -1,3517 +1,3517 @@
 /*-
  * SPDX-License-Identifier: (BSD-2-Clause-FreeBSD AND BSD-3-Clause)
  *
  * Copyright (c) 2002 Networks Associates Technology, Inc.
  * All rights reserved.
  *
  * This software was developed for the FreeBSD Project by Marshall
  * Kirk McKusick and Network Associates Laboratories, the Security
  * Research Division of Network Associates, Inc. under DARPA/SPAWAR
  * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS
  * research program
  *
  * 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 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 AUTHOR 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.
  *
  * Copyright (c) 1982, 1986, 1989, 1993
  *	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_alloc.c	8.18 (Berkeley) 5/26/95
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include "opt_quota.h"
 
 #include <sys/param.h>
 #include <sys/capsicum.h>
 #include <sys/gsb_crc32.h>
 #include <sys/systm.h>
 #include <sys/bio.h>
 #include <sys/buf.h>
 #include <sys/conf.h>
 #include <sys/fcntl.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>
 #include <sys/priv.h>
 #include <sys/proc.h>
 #include <sys/vnode.h>
 #include <sys/mount.h>
 #include <sys/kernel.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
 #include <sys/syslog.h>
 #include <sys/taskqueue.h>
 
 #include <security/audit/audit.h>
 
 #include <geom/geom.h>
 #include <geom/geom_vfs.h>
 
 #include <ufs/ufs/dir.h>
 #include <ufs/ufs/extattr.h>
 #include <ufs/ufs/quota.h>
 #include <ufs/ufs/inode.h>
 #include <ufs/ufs/ufs_extern.h>
 #include <ufs/ufs/ufsmount.h>
 
 #include <ufs/ffs/fs.h>
 #include <ufs/ffs/ffs_extern.h>
 #include <ufs/ffs/softdep.h>
 
 typedef ufs2_daddr_t allocfcn_t(struct inode *ip, u_int cg, ufs2_daddr_t bpref,
 				  int size, int rsize);
 
 static ufs2_daddr_t ffs_alloccg(struct inode *, u_int, ufs2_daddr_t, int, int);
 static ufs2_daddr_t
 	      ffs_alloccgblk(struct inode *, struct buf *, ufs2_daddr_t, int);
 static void	ffs_blkfree_cg(struct ufsmount *, struct fs *,
 		    struct vnode *, ufs2_daddr_t, long, ino_t,
 		    struct workhead *);
 #ifdef INVARIANTS
 static int	ffs_checkblk(struct inode *, ufs2_daddr_t, long);
 #endif
 static ufs2_daddr_t ffs_clusteralloc(struct inode *, u_int, ufs2_daddr_t, int);
 static ino_t	ffs_dirpref(struct inode *);
 static ufs2_daddr_t ffs_fragextend(struct inode *, u_int, ufs2_daddr_t,
 		    int, int);
 static ufs2_daddr_t	ffs_hashalloc
 		(struct inode *, u_int, ufs2_daddr_t, int, int, allocfcn_t *);
 static ufs2_daddr_t ffs_nodealloccg(struct inode *, u_int, ufs2_daddr_t, int,
 		    int);
 static ufs1_daddr_t ffs_mapsearch(struct fs *, struct cg *, ufs2_daddr_t, int);
 static int	ffs_reallocblks_ufs1(struct vop_reallocblks_args *);
 static int	ffs_reallocblks_ufs2(struct vop_reallocblks_args *);
 static void	ffs_ckhash_cg(struct buf *);
 
 /*
  * Allocate a block in the filesystem.
  *
  * The size of the requested block is given, which must be some
  * multiple of fs_fsize and <= fs_bsize.
  * A preference may be optionally specified. If a preference is given
  * the following hierarchy is used to allocate a block:
  *   1) allocate the requested block.
  *   2) allocate a rotationally optimal block in the same cylinder.
  *   3) allocate a block in the same cylinder group.
  *   4) quadradically rehash into other cylinder groups, until an
  *      available block is located.
  * If no block preference is given the following hierarchy is used
  * to allocate a block:
  *   1) allocate a block in the cylinder group that contains the
  *      inode for the file.
  *   2) quadradically rehash into other cylinder groups, until an
  *      available block is located.
  */
 int
 ffs_alloc(ip, lbn, bpref, size, flags, cred, bnp)
 	struct inode *ip;
 	ufs2_daddr_t lbn, bpref;
 	int size, flags;
 	struct ucred *cred;
 	ufs2_daddr_t *bnp;
 {
 	struct fs *fs;
 	struct ufsmount *ump;
 	ufs2_daddr_t bno;
 	u_int cg, reclaimed;
 	int64_t delta;
 #ifdef QUOTA
 	int error;
 #endif
 
 	*bnp = 0;
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	mtx_assert(UFS_MTX(ump), MA_OWNED);
 #ifdef INVARIANTS
 	if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0) {
 		printf("dev = %s, bsize = %ld, size = %d, fs = %s\n",
 		    devtoname(ump->um_dev), (long)fs->fs_bsize, size,
 		    fs->fs_fsmnt);
 		panic("ffs_alloc: bad size");
 	}
 	if (cred == NOCRED)
 		panic("ffs_alloc: missing credential");
 #endif /* INVARIANTS */
 	reclaimed = 0;
 retry:
 #ifdef QUOTA
 	UFS_UNLOCK(ump);
 	error = chkdq(ip, btodb(size), cred, 0);
 	if (error)
 		return (error);
 	UFS_LOCK(ump);
 #endif
 	if (size == fs->fs_bsize && fs->fs_cstotal.cs_nbfree == 0)
 		goto nospace;
 	if (priv_check_cred(cred, PRIV_VFS_BLOCKRESERVE) &&
 	    freespace(fs, fs->fs_minfree) - numfrags(fs, size) < 0)
 		goto nospace;
 	if (bpref >= fs->fs_size)
 		bpref = 0;
 	if (bpref == 0)
 		cg = ino_to_cg(fs, ip->i_number);
 	else
 		cg = dtog(fs, bpref);
 	bno = ffs_hashalloc(ip, cg, bpref, size, size, ffs_alloccg);
 	if (bno > 0) {
 		delta = btodb(size);
 		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + delta);
 		if (flags & IO_EXT)
 			UFS_INODE_SET_FLAG(ip, IN_CHANGE);
 		else
 			UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
 		*bnp = bno;
 		return (0);
 	}
 nospace:
 #ifdef QUOTA
 	UFS_UNLOCK(ump);
 	/*
 	 * Restore user's disk quota because allocation failed.
 	 */
 	(void) chkdq(ip, -btodb(size), cred, FORCE);
 	UFS_LOCK(ump);
 #endif
 	if (reclaimed == 0 && (flags & IO_BUFLOCKED) == 0) {
 		reclaimed = 1;
 		softdep_request_cleanup(fs, ITOV(ip), cred, FLUSH_BLOCKS_WAIT);
 		goto retry;
 	}
 	if (ffs_fsfail_cleanup_locked(ump, 0)) {
 		UFS_UNLOCK(ump);
 		return (ENXIO);
 	}
 	if (reclaimed > 0 &&
 	    ppsratecheck(&ump->um_last_fullmsg, &ump->um_secs_fullmsg, 1)) {
 		UFS_UNLOCK(ump);
 		ffs_fserr(fs, ip->i_number, "filesystem full");
 		uprintf("\n%s: write failed, filesystem is full\n",
 		    fs->fs_fsmnt);
 	} else {
 		UFS_UNLOCK(ump);
 	}
 	return (ENOSPC);
 }
 
 /*
  * Reallocate a fragment to a bigger size
  *
  * The number and size of the old block is given, and a preference
  * and new size is also specified. The allocator attempts to extend
  * the original block. Failing that, the regular block allocator is
  * invoked to get an appropriate block.
  */
 int
 ffs_realloccg(ip, lbprev, bprev, bpref, osize, nsize, flags, cred, bpp)
 	struct inode *ip;
 	ufs2_daddr_t lbprev;
 	ufs2_daddr_t bprev;
 	ufs2_daddr_t bpref;
 	int osize, nsize, flags;
 	struct ucred *cred;
 	struct buf **bpp;
 {
 	struct vnode *vp;
 	struct fs *fs;
 	struct buf *bp;
 	struct ufsmount *ump;
 	u_int cg, request, reclaimed;
 	int error, gbflags;
 	ufs2_daddr_t bno;
 	int64_t delta;
 
 	vp = ITOV(ip);
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	bp = NULL;
 	gbflags = (flags & BA_UNMAPPED) != 0 ? GB_UNMAPPED : 0;
 
 	mtx_assert(UFS_MTX(ump), MA_OWNED);
 #ifdef INVARIANTS
 	if (vp->v_mount->mnt_kern_flag & MNTK_SUSPENDED)
 		panic("ffs_realloccg: allocation on suspended filesystem");
 	if ((u_int)osize > fs->fs_bsize || fragoff(fs, osize) != 0 ||
 	    (u_int)nsize > fs->fs_bsize || fragoff(fs, nsize) != 0) {
 		printf(
 		"dev = %s, bsize = %ld, osize = %d, nsize = %d, fs = %s\n",
 		    devtoname(ump->um_dev), (long)fs->fs_bsize, osize,
 		    nsize, fs->fs_fsmnt);
 		panic("ffs_realloccg: bad size");
 	}
 	if (cred == NOCRED)
 		panic("ffs_realloccg: missing credential");
 #endif /* INVARIANTS */
 	reclaimed = 0;
 retry:
 	if (priv_check_cred(cred, PRIV_VFS_BLOCKRESERVE) &&
 	    freespace(fs, fs->fs_minfree) -  numfrags(fs, nsize - osize) < 0) {
 		goto nospace;
 	}
 	if (bprev == 0) {
 		printf("dev = %s, bsize = %ld, bprev = %jd, fs = %s\n",
 		    devtoname(ump->um_dev), (long)fs->fs_bsize, (intmax_t)bprev,
 		    fs->fs_fsmnt);
 		panic("ffs_realloccg: bad bprev");
 	}
 	UFS_UNLOCK(ump);
 	/*
 	 * Allocate the extra space in the buffer.
 	 */
 	error = bread_gb(vp, lbprev, osize, NOCRED, gbflags, &bp);
 	if (error) {
 		return (error);
 	}
 
 	if (bp->b_blkno == bp->b_lblkno) {
 		if (lbprev >= UFS_NDADDR)
 			panic("ffs_realloccg: lbprev out of range");
 		bp->b_blkno = fsbtodb(fs, bprev);
 	}
 
 #ifdef QUOTA
 	error = chkdq(ip, btodb(nsize - osize), cred, 0);
 	if (error) {
 		brelse(bp);
 		return (error);
 	}
 #endif
 	/*
 	 * Check for extension in the existing location.
 	 */
 	*bpp = NULL;
 	cg = dtog(fs, bprev);
 	UFS_LOCK(ump);
 	bno = ffs_fragextend(ip, cg, bprev, osize, nsize);
 	if (bno) {
 		if (bp->b_blkno != fsbtodb(fs, bno))
 			panic("ffs_realloccg: bad blockno");
 		delta = btodb(nsize - osize);
 		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + delta);
 		if (flags & IO_EXT)
 			UFS_INODE_SET_FLAG(ip, IN_CHANGE);
 		else
 			UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
 		allocbuf(bp, nsize);
 		bp->b_flags |= B_DONE;
 		vfs_bio_bzero_buf(bp, osize, nsize - osize);
 		if ((bp->b_flags & (B_MALLOC | B_VMIO)) == B_VMIO)
 			vfs_bio_set_valid(bp, osize, nsize - osize);
 		*bpp = bp;
 		return (0);
 	}
 	/*
 	 * Allocate a new disk location.
 	 */
 	if (bpref >= fs->fs_size)
 		bpref = 0;
 	switch ((int)fs->fs_optim) {
 	case FS_OPTSPACE:
 		/*
 		 * Allocate an exact sized fragment. Although this makes
 		 * best use of space, we will waste time relocating it if
 		 * the file continues to grow. If the fragmentation is
 		 * less than half of the minimum free reserve, we choose
 		 * to begin optimizing for time.
 		 */
 		request = nsize;
 		if (fs->fs_minfree <= 5 ||
 		    fs->fs_cstotal.cs_nffree >
 		    (off_t)fs->fs_dsize * fs->fs_minfree / (2 * 100))
 			break;
 		log(LOG_NOTICE, "%s: optimization changed from SPACE to TIME\n",
 			fs->fs_fsmnt);
 		fs->fs_optim = FS_OPTTIME;
 		break;
 	case FS_OPTTIME:
 		/*
 		 * At this point we have discovered a file that is trying to
 		 * grow a small fragment to a larger fragment. To save time,
 		 * we allocate a full sized block, then free the unused portion.
 		 * If the file continues to grow, the `ffs_fragextend' call
 		 * above will be able to grow it in place without further
 		 * copying. If aberrant programs cause disk fragmentation to
 		 * grow within 2% of the free reserve, we choose to begin
 		 * optimizing for space.
 		 */
 		request = fs->fs_bsize;
 		if (fs->fs_cstotal.cs_nffree <
 		    (off_t)fs->fs_dsize * (fs->fs_minfree - 2) / 100)
 			break;
 		log(LOG_NOTICE, "%s: optimization changed from TIME to SPACE\n",
 			fs->fs_fsmnt);
 		fs->fs_optim = FS_OPTSPACE;
 		break;
 	default:
 		printf("dev = %s, optim = %ld, fs = %s\n",
 		    devtoname(ump->um_dev), (long)fs->fs_optim, fs->fs_fsmnt);
 		panic("ffs_realloccg: bad optim");
 		/* NOTREACHED */
 	}
 	bno = ffs_hashalloc(ip, cg, bpref, request, nsize, ffs_alloccg);
 	if (bno > 0) {
 		bp->b_blkno = fsbtodb(fs, bno);
 		if (!DOINGSOFTDEP(vp))
 			/*
 			 * The usual case is that a smaller fragment that
 			 * was just allocated has been replaced with a bigger
 			 * fragment or a full-size block. If it is marked as
 			 * B_DELWRI, the current contents have not been written
 			 * to disk. It is possible that the block was written
 			 * earlier, but very uncommon. If the block has never
 			 * been written, there is no need to send a BIO_DELETE
 			 * for it when it is freed. The gain from avoiding the
 			 * TRIMs for the common case of unwritten blocks far
 			 * exceeds the cost of the write amplification for the
 			 * uncommon case of failing to send a TRIM for a block
 			 * that had been written.
 			 */
 			ffs_blkfree(ump, fs, ump->um_devvp, bprev, (long)osize,
 			    ip->i_number, vp->v_type, NULL,
 			    (bp->b_flags & B_DELWRI) != 0 ?
 			    NOTRIM_KEY : SINGLETON_KEY);
 		delta = btodb(nsize - osize);
 		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + delta);
 		if (flags & IO_EXT)
 			UFS_INODE_SET_FLAG(ip, IN_CHANGE);
 		else
 			UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
 		allocbuf(bp, nsize);
 		bp->b_flags |= B_DONE;
 		vfs_bio_bzero_buf(bp, osize, nsize - osize);
 		if ((bp->b_flags & (B_MALLOC | B_VMIO)) == B_VMIO)
 			vfs_bio_set_valid(bp, osize, nsize - osize);
 		*bpp = bp;
 		return (0);
 	}
 #ifdef QUOTA
 	UFS_UNLOCK(ump);
 	/*
 	 * Restore user's disk quota because allocation failed.
 	 */
 	(void) chkdq(ip, -btodb(nsize - osize), cred, FORCE);
 	UFS_LOCK(ump);
 #endif
 nospace:
 	/*
 	 * no space available
 	 */
 	if (reclaimed == 0 && (flags & IO_BUFLOCKED) == 0) {
 		reclaimed = 1;
 		UFS_UNLOCK(ump);
 		if (bp) {
 			brelse(bp);
 			bp = NULL;
 		}
 		UFS_LOCK(ump);
 		softdep_request_cleanup(fs, vp, cred, FLUSH_BLOCKS_WAIT);
 		goto retry;
 	}
 	if (bp)
 		brelse(bp);
 	if (ffs_fsfail_cleanup_locked(ump, 0)) {
 		UFS_UNLOCK(ump);
 		return (ENXIO);
 	}
 	if (reclaimed > 0 &&
 	    ppsratecheck(&ump->um_last_fullmsg, &ump->um_secs_fullmsg, 1)) {
 		UFS_UNLOCK(ump);
 		ffs_fserr(fs, ip->i_number, "filesystem full");
 		uprintf("\n%s: write failed, filesystem is full\n",
 		    fs->fs_fsmnt);
 	} else {
 		UFS_UNLOCK(ump);
 	}
 	return (ENOSPC);
 }
 
 /*
  * Reallocate a sequence of blocks into a contiguous sequence of blocks.
  *
  * The vnode and an array of buffer pointers for a range of sequential
  * logical blocks to be made contiguous is given. The allocator attempts
  * to find a range of sequential blocks starting as close as possible
  * from the end of the allocation for the logical block immediately
  * preceding the current range. If successful, the physical block numbers
  * in the buffer pointers and in the inode are changed to reflect the new
  * allocation. If unsuccessful, the allocation is left unchanged. The
  * success in doing the reallocation is returned. Note that the error
  * return is not reflected back to the user. Rather the previous block
  * allocation will be used.
  */
 
 SYSCTL_NODE(_vfs, OID_AUTO, ffs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "FFS filesystem");
 
 static int doasyncfree = 1;
 SYSCTL_INT(_vfs_ffs, OID_AUTO, doasyncfree, CTLFLAG_RW, &doasyncfree, 0,
 "do not force synchronous writes when blocks are reallocated");
 
 static int doreallocblks = 1;
 SYSCTL_INT(_vfs_ffs, OID_AUTO, doreallocblks, CTLFLAG_RW, &doreallocblks, 0,
 "enable block reallocation");
 
 static int dotrimcons = 1;
 SYSCTL_INT(_vfs_ffs, OID_AUTO, dotrimcons, CTLFLAG_RWTUN, &dotrimcons, 0,
 "enable BIO_DELETE / TRIM consolidation");
 
 static int maxclustersearch = 10;
 SYSCTL_INT(_vfs_ffs, OID_AUTO, maxclustersearch, CTLFLAG_RW, &maxclustersearch,
 0, "max number of cylinder group to search for contigous blocks");
 
 #ifdef DIAGNOSTIC
 static int prtrealloc = 0;
 SYSCTL_INT(_debug, OID_AUTO, ffs_prtrealloc, CTLFLAG_RW, &prtrealloc, 0,
 	"print out FFS filesystem block reallocation operations");
 #endif
 
 int
 ffs_reallocblks(ap)
 	struct vop_reallocblks_args /* {
 		struct vnode *a_vp;
 		struct cluster_save *a_buflist;
 	} */ *ap;
 {
 	struct ufsmount *ump;
 
 	/*
 	 * We used to skip reallocating the blocks of a file into a
 	 * contiguous sequence if the underlying flash device requested
 	 * BIO_DELETE notifications, because devices that benefit from
 	 * BIO_DELETE also benefit from not moving the data. However,
 	 * the destination for the data is usually moved before the data
 	 * is written to the initially allocated location, so we rarely
 	 * suffer the penalty of extra writes. With the addition of the
 	 * consolidation of contiguous blocks into single BIO_DELETE
 	 * operations, having fewer but larger contiguous blocks reduces
 	 * the number of (slow and expensive) BIO_DELETE operations. So
 	 * when doing BIO_DELETE consolidation, we do block reallocation.
 	 *
 	 * Skip if reallocblks has been disabled globally.
 	 */
 	ump = ap->a_vp->v_mount->mnt_data;
 	if ((((ump->um_flags) & UM_CANDELETE) != 0 && dotrimcons == 0) ||
 	    doreallocblks == 0)
 		return (ENOSPC);
 
 	/*
 	 * We can't wait in softdep prealloc as it may fsync and recurse
 	 * here.  Instead we simply fail to reallocate blocks if this
 	 * rare condition arises.
 	 */
 	if (DOINGSUJ(ap->a_vp))
 		if (softdep_prealloc(ap->a_vp, MNT_NOWAIT) != 0)
 			return (ENOSPC);
 	if (ump->um_fstype == UFS1)
 		return (ffs_reallocblks_ufs1(ap));
 	return (ffs_reallocblks_ufs2(ap));
 }
 
 static int
 ffs_reallocblks_ufs1(ap)
 	struct vop_reallocblks_args /* {
 		struct vnode *a_vp;
 		struct cluster_save *a_buflist;
 	} */ *ap;
 {
 	struct fs *fs;
 	struct inode *ip;
 	struct vnode *vp;
 	struct buf *sbp, *ebp, *bp;
 	ufs1_daddr_t *bap, *sbap, *ebap;
 	struct cluster_save *buflist;
 	struct ufsmount *ump;
 	ufs_lbn_t start_lbn, end_lbn;
 	ufs1_daddr_t soff, newblk, blkno;
 	ufs2_daddr_t pref;
 	struct indir start_ap[UFS_NIADDR + 1], end_ap[UFS_NIADDR + 1], *idp;
 	int i, cg, len, start_lvl, end_lvl, ssize;
 
 	vp = ap->a_vp;
 	ip = VTOI(vp);
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	/*
 	 * If we are not tracking block clusters or if we have less than 4%
 	 * free blocks left, then do not attempt to cluster. Running with
 	 * less than 5% free block reserve is not recommended and those that
 	 * choose to do so do not expect to have good file layout.
 	 */
 	if (fs->fs_contigsumsize <= 0 || freespace(fs, 4) < 0)
 		return (ENOSPC);
 	buflist = ap->a_buflist;
 	len = buflist->bs_nchildren;
 	start_lbn = buflist->bs_children[0]->b_lblkno;
 	end_lbn = start_lbn + len - 1;
 #ifdef INVARIANTS
 	for (i = 0; i < len; i++)
 		if (!ffs_checkblk(ip,
 		   dbtofsb(fs, buflist->bs_children[i]->b_blkno), fs->fs_bsize))
 			panic("ffs_reallocblks: unallocated block 1");
 	for (i = 1; i < len; i++)
 		if (buflist->bs_children[i]->b_lblkno != start_lbn + i)
 			panic("ffs_reallocblks: non-logical cluster");
 	blkno = buflist->bs_children[0]->b_blkno;
 	ssize = fsbtodb(fs, fs->fs_frag);
 	for (i = 1; i < len - 1; i++)
 		if (buflist->bs_children[i]->b_blkno != blkno + (i * ssize))
 			panic("ffs_reallocblks: non-physical cluster %d", i);
 #endif
 	/*
 	 * If the cluster crosses the boundary for the first indirect
 	 * block, leave space for the indirect block. Indirect blocks
 	 * are initially laid out in a position after the last direct
 	 * block. Block reallocation would usually destroy locality by
 	 * moving the indirect block out of the way to make room for
 	 * data blocks if we didn't compensate here. We should also do
 	 * this for other indirect block boundaries, but it is only
 	 * important for the first one.
 	 */
 	if (start_lbn < UFS_NDADDR && end_lbn >= UFS_NDADDR)
 		return (ENOSPC);
 	/*
 	 * If the latest allocation is in a new cylinder group, assume that
 	 * the filesystem has decided to move and do not force it back to
 	 * the previous cylinder group.
 	 */
 	if (dtog(fs, dbtofsb(fs, buflist->bs_children[0]->b_blkno)) !=
 	    dtog(fs, dbtofsb(fs, buflist->bs_children[len - 1]->b_blkno)))
 		return (ENOSPC);
 	if (ufs_getlbns(vp, start_lbn, start_ap, &start_lvl) ||
 	    ufs_getlbns(vp, end_lbn, end_ap, &end_lvl))
 		return (ENOSPC);
 	/*
 	 * Get the starting offset and block map for the first block.
 	 */
 	if (start_lvl == 0) {
 		sbap = &ip->i_din1->di_db[0];
 		soff = start_lbn;
 	} else {
 		idp = &start_ap[start_lvl - 1];
 		if (bread(vp, idp->in_lbn, (int)fs->fs_bsize, NOCRED, &sbp)) {
 			brelse(sbp);
 			return (ENOSPC);
 		}
 		sbap = (ufs1_daddr_t *)sbp->b_data;
 		soff = idp->in_off;
 	}
 	/*
 	 * If the block range spans two block maps, get the second map.
 	 */
 	ebap = NULL;
 	if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) {
 		ssize = len;
 	} else {
 #ifdef INVARIANTS
 		if (start_lvl > 0 &&
 		    start_ap[start_lvl - 1].in_lbn == idp->in_lbn)
 			panic("ffs_reallocblk: start == end");
 #endif
 		ssize = len - (idp->in_off + 1);
 		if (bread(vp, idp->in_lbn, (int)fs->fs_bsize, NOCRED, &ebp))
 			goto fail;
 		ebap = (ufs1_daddr_t *)ebp->b_data;
 	}
 	/*
 	 * Find the preferred location for the cluster. If we have not
 	 * previously failed at this endeavor, then follow our standard
 	 * preference calculation. If we have failed at it, then pick up
 	 * where we last ended our search.
 	 */
 	UFS_LOCK(ump);
 	if (ip->i_nextclustercg == -1)
 		pref = ffs_blkpref_ufs1(ip, start_lbn, soff, sbap);
 	else
 		pref = cgdata(fs, ip->i_nextclustercg);
 	/*
 	 * Search the block map looking for an allocation of the desired size.
 	 * To avoid wasting too much time, we limit the number of cylinder
 	 * groups that we will search.
 	 */
 	cg = dtog(fs, pref);
 	for (i = min(maxclustersearch, fs->fs_ncg); i > 0; i--) {
 		if ((newblk = ffs_clusteralloc(ip, cg, pref, len)) != 0)
 			break;
 		cg += 1;
 		if (cg >= fs->fs_ncg)
 			cg = 0;
 	}
 	/*
 	 * If we have failed in our search, record where we gave up for
 	 * next time. Otherwise, fall back to our usual search citerion.
 	 */
 	if (newblk == 0) {
 		ip->i_nextclustercg = cg;
 		UFS_UNLOCK(ump);
 		goto fail;
 	}
 	ip->i_nextclustercg = -1;
 	/*
 	 * We have found a new contiguous block.
 	 *
 	 * First we have to replace the old block pointers with the new
 	 * block pointers in the inode and indirect blocks associated
 	 * with the file.
 	 */
 #ifdef DIAGNOSTIC
 	if (prtrealloc)
 		printf("realloc: ino %ju, lbns %jd-%jd\n\told:",
 		    (uintmax_t)ip->i_number,
 		    (intmax_t)start_lbn, (intmax_t)end_lbn);
 #endif
 	blkno = newblk;
 	for (bap = &sbap[soff], i = 0; i < len; i++, blkno += fs->fs_frag) {
 		if (i == ssize) {
 			bap = ebap;
 			soff = -i;
 		}
 #ifdef INVARIANTS
 		if (!ffs_checkblk(ip,
 		   dbtofsb(fs, buflist->bs_children[i]->b_blkno), fs->fs_bsize))
 			panic("ffs_reallocblks: unallocated block 2");
 		if (dbtofsb(fs, buflist->bs_children[i]->b_blkno) != *bap)
 			panic("ffs_reallocblks: alloc mismatch");
 #endif
 #ifdef DIAGNOSTIC
 		if (prtrealloc)
 			printf(" %d,", *bap);
 #endif
 		if (DOINGSOFTDEP(vp)) {
 			if (sbap == &ip->i_din1->di_db[0] && i < ssize)
 				softdep_setup_allocdirect(ip, start_lbn + i,
 				    blkno, *bap, fs->fs_bsize, fs->fs_bsize,
 				    buflist->bs_children[i]);
 			else
 				softdep_setup_allocindir_page(ip, start_lbn + i,
 				    i < ssize ? sbp : ebp, soff + i, blkno,
 				    *bap, buflist->bs_children[i]);
 		}
 		*bap++ = blkno;
 	}
 	/*
 	 * Next we must write out the modified inode and indirect blocks.
 	 * For strict correctness, the writes should be synchronous since
 	 * the old block values may have been written to disk. In practise
 	 * they are almost never written, but if we are concerned about
 	 * strict correctness, the `doasyncfree' flag should be set to zero.
 	 *
 	 * The test on `doasyncfree' should be changed to test a flag
 	 * that shows whether the associated buffers and inodes have
 	 * been written. The flag should be set when the cluster is
 	 * started and cleared whenever the buffer or inode is flushed.
 	 * We can then check below to see if it is set, and do the
 	 * synchronous write only when it has been cleared.
 	 */
 	if (sbap != &ip->i_din1->di_db[0]) {
 		if (doasyncfree)
 			bdwrite(sbp);
 		else
 			bwrite(sbp);
 	} else {
 		UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
 		if (!doasyncfree)
 			ffs_update(vp, 1);
 	}
 	if (ssize < len) {
 		if (doasyncfree)
 			bdwrite(ebp);
 		else
 			bwrite(ebp);
 	}
 	/*
 	 * Last, free the old blocks and assign the new blocks to the buffers.
 	 */
 #ifdef DIAGNOSTIC
 	if (prtrealloc)
 		printf("\n\tnew:");
 #endif
 	for (blkno = newblk, i = 0; i < len; i++, blkno += fs->fs_frag) {
 		bp = buflist->bs_children[i];
 		if (!DOINGSOFTDEP(vp))
 			/*
 			 * The usual case is that a set of N-contiguous blocks
 			 * that was just allocated has been replaced with a
 			 * set of N+1-contiguous blocks. If they are marked as
 			 * B_DELWRI, the current contents have not been written
 			 * to disk. It is possible that the blocks were written
 			 * earlier, but very uncommon. If the blocks have never
 			 * been written, there is no need to send a BIO_DELETE
 			 * for them when they are freed. The gain from avoiding
 			 * the TRIMs for the common case of unwritten blocks
 			 * far exceeds the cost of the write amplification for
 			 * the uncommon case of failing to send a TRIM for the
 			 * blocks that had been written.
 			 */
 			ffs_blkfree(ump, fs, ump->um_devvp,
 			    dbtofsb(fs, bp->b_blkno),
 			    fs->fs_bsize, ip->i_number, vp->v_type, NULL,
 			    (bp->b_flags & B_DELWRI) != 0 ?
 			    NOTRIM_KEY : SINGLETON_KEY);
 		bp->b_blkno = fsbtodb(fs, blkno);
 #ifdef INVARIANTS
 		if (!ffs_checkblk(ip, dbtofsb(fs, bp->b_blkno), fs->fs_bsize))
 			panic("ffs_reallocblks: unallocated block 3");
 #endif
 #ifdef DIAGNOSTIC
 		if (prtrealloc)
 			printf(" %d,", blkno);
 #endif
 	}
 #ifdef DIAGNOSTIC
 	if (prtrealloc) {
 		prtrealloc--;
 		printf("\n");
 	}
 #endif
 	return (0);
 
 fail:
 	if (ssize < len)
 		brelse(ebp);
 	if (sbap != &ip->i_din1->di_db[0])
 		brelse(sbp);
 	return (ENOSPC);
 }
 
 static int
 ffs_reallocblks_ufs2(ap)
 	struct vop_reallocblks_args /* {
 		struct vnode *a_vp;
 		struct cluster_save *a_buflist;
 	} */ *ap;
 {
 	struct fs *fs;
 	struct inode *ip;
 	struct vnode *vp;
 	struct buf *sbp, *ebp, *bp;
 	ufs2_daddr_t *bap, *sbap, *ebap;
 	struct cluster_save *buflist;
 	struct ufsmount *ump;
 	ufs_lbn_t start_lbn, end_lbn;
 	ufs2_daddr_t soff, newblk, blkno, pref;
 	struct indir start_ap[UFS_NIADDR + 1], end_ap[UFS_NIADDR + 1], *idp;
 	int i, cg, len, start_lvl, end_lvl, ssize;
 
 	vp = ap->a_vp;
 	ip = VTOI(vp);
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	/*
 	 * If we are not tracking block clusters or if we have less than 4%
 	 * free blocks left, then do not attempt to cluster. Running with
 	 * less than 5% free block reserve is not recommended and those that
 	 * choose to do so do not expect to have good file layout.
 	 */
 	if (fs->fs_contigsumsize <= 0 || freespace(fs, 4) < 0)
 		return (ENOSPC);
 	buflist = ap->a_buflist;
 	len = buflist->bs_nchildren;
 	start_lbn = buflist->bs_children[0]->b_lblkno;
 	end_lbn = start_lbn + len - 1;
 #ifdef INVARIANTS
 	for (i = 0; i < len; i++)
 		if (!ffs_checkblk(ip,
 		   dbtofsb(fs, buflist->bs_children[i]->b_blkno), fs->fs_bsize))
 			panic("ffs_reallocblks: unallocated block 1");
 	for (i = 1; i < len; i++)
 		if (buflist->bs_children[i]->b_lblkno != start_lbn + i)
 			panic("ffs_reallocblks: non-logical cluster");
 	blkno = buflist->bs_children[0]->b_blkno;
 	ssize = fsbtodb(fs, fs->fs_frag);
 	for (i = 1; i < len - 1; i++)
 		if (buflist->bs_children[i]->b_blkno != blkno + (i * ssize))
 			panic("ffs_reallocblks: non-physical cluster %d", i);
 #endif
 	/*
 	 * If the cluster crosses the boundary for the first indirect
 	 * block, do not move anything in it. Indirect blocks are
 	 * usually initially laid out in a position between the data
 	 * blocks. Block reallocation would usually destroy locality by
 	 * moving the indirect block out of the way to make room for
 	 * data blocks if we didn't compensate here. We should also do
 	 * this for other indirect block boundaries, but it is only
 	 * important for the first one.
 	 */
 	if (start_lbn < UFS_NDADDR && end_lbn >= UFS_NDADDR)
 		return (ENOSPC);
 	/*
 	 * If the latest allocation is in a new cylinder group, assume that
 	 * the filesystem has decided to move and do not force it back to
 	 * the previous cylinder group.
 	 */
 	if (dtog(fs, dbtofsb(fs, buflist->bs_children[0]->b_blkno)) !=
 	    dtog(fs, dbtofsb(fs, buflist->bs_children[len - 1]->b_blkno)))
 		return (ENOSPC);
 	if (ufs_getlbns(vp, start_lbn, start_ap, &start_lvl) ||
 	    ufs_getlbns(vp, end_lbn, end_ap, &end_lvl))
 		return (ENOSPC);
 	/*
 	 * Get the starting offset and block map for the first block.
 	 */
 	if (start_lvl == 0) {
 		sbap = &ip->i_din2->di_db[0];
 		soff = start_lbn;
 	} else {
 		idp = &start_ap[start_lvl - 1];
 		if (bread(vp, idp->in_lbn, (int)fs->fs_bsize, NOCRED, &sbp)) {
 			brelse(sbp);
 			return (ENOSPC);
 		}
 		sbap = (ufs2_daddr_t *)sbp->b_data;
 		soff = idp->in_off;
 	}
 	/*
 	 * If the block range spans two block maps, get the second map.
 	 */
 	ebap = NULL;
 	if (end_lvl == 0 || (idp = &end_ap[end_lvl - 1])->in_off + 1 >= len) {
 		ssize = len;
 	} else {
 #ifdef INVARIANTS
 		if (start_lvl > 0 &&
 		    start_ap[start_lvl - 1].in_lbn == idp->in_lbn)
 			panic("ffs_reallocblk: start == end");
 #endif
 		ssize = len - (idp->in_off + 1);
 		if (bread(vp, idp->in_lbn, (int)fs->fs_bsize, NOCRED, &ebp))
 			goto fail;
 		ebap = (ufs2_daddr_t *)ebp->b_data;
 	}
 	/*
 	 * Find the preferred location for the cluster. If we have not
 	 * previously failed at this endeavor, then follow our standard
 	 * preference calculation. If we have failed at it, then pick up
 	 * where we last ended our search.
 	 */
 	UFS_LOCK(ump);
 	if (ip->i_nextclustercg == -1)
 		pref = ffs_blkpref_ufs2(ip, start_lbn, soff, sbap);
 	else
 		pref = cgdata(fs, ip->i_nextclustercg);
 	/*
 	 * Search the block map looking for an allocation of the desired size.
 	 * To avoid wasting too much time, we limit the number of cylinder
 	 * groups that we will search.
 	 */
 	cg = dtog(fs, pref);
 	for (i = min(maxclustersearch, fs->fs_ncg); i > 0; i--) {
 		if ((newblk = ffs_clusteralloc(ip, cg, pref, len)) != 0)
 			break;
 		cg += 1;
 		if (cg >= fs->fs_ncg)
 			cg = 0;
 	}
 	/*
 	 * If we have failed in our search, record where we gave up for
 	 * next time. Otherwise, fall back to our usual search citerion.
 	 */
 	if (newblk == 0) {
 		ip->i_nextclustercg = cg;
 		UFS_UNLOCK(ump);
 		goto fail;
 	}
 	ip->i_nextclustercg = -1;
 	/*
 	 * We have found a new contiguous block.
 	 *
 	 * First we have to replace the old block pointers with the new
 	 * block pointers in the inode and indirect blocks associated
 	 * with the file.
 	 */
 #ifdef DIAGNOSTIC
 	if (prtrealloc)
 		printf("realloc: ino %ju, lbns %jd-%jd\n\told:", (uintmax_t)ip->i_number,
 		    (intmax_t)start_lbn, (intmax_t)end_lbn);
 #endif
 	blkno = newblk;
 	for (bap = &sbap[soff], i = 0; i < len; i++, blkno += fs->fs_frag) {
 		if (i == ssize) {
 			bap = ebap;
 			soff = -i;
 		}
 #ifdef INVARIANTS
 		if (!ffs_checkblk(ip,
 		   dbtofsb(fs, buflist->bs_children[i]->b_blkno), fs->fs_bsize))
 			panic("ffs_reallocblks: unallocated block 2");
 		if (dbtofsb(fs, buflist->bs_children[i]->b_blkno) != *bap)
 			panic("ffs_reallocblks: alloc mismatch");
 #endif
 #ifdef DIAGNOSTIC
 		if (prtrealloc)
 			printf(" %jd,", (intmax_t)*bap);
 #endif
 		if (DOINGSOFTDEP(vp)) {
 			if (sbap == &ip->i_din2->di_db[0] && i < ssize)
 				softdep_setup_allocdirect(ip, start_lbn + i,
 				    blkno, *bap, fs->fs_bsize, fs->fs_bsize,
 				    buflist->bs_children[i]);
 			else
 				softdep_setup_allocindir_page(ip, start_lbn + i,
 				    i < ssize ? sbp : ebp, soff + i, blkno,
 				    *bap, buflist->bs_children[i]);
 		}
 		*bap++ = blkno;
 	}
 	/*
 	 * Next we must write out the modified inode and indirect blocks.
 	 * For strict correctness, the writes should be synchronous since
 	 * the old block values may have been written to disk. In practise
 	 * they are almost never written, but if we are concerned about
 	 * strict correctness, the `doasyncfree' flag should be set to zero.
 	 *
 	 * The test on `doasyncfree' should be changed to test a flag
 	 * that shows whether the associated buffers and inodes have
 	 * been written. The flag should be set when the cluster is
 	 * started and cleared whenever the buffer or inode is flushed.
 	 * We can then check below to see if it is set, and do the
 	 * synchronous write only when it has been cleared.
 	 */
 	if (sbap != &ip->i_din2->di_db[0]) {
 		if (doasyncfree)
 			bdwrite(sbp);
 		else
 			bwrite(sbp);
 	} else {
 		UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
 		if (!doasyncfree)
 			ffs_update(vp, 1);
 	}
 	if (ssize < len) {
 		if (doasyncfree)
 			bdwrite(ebp);
 		else
 			bwrite(ebp);
 	}
 	/*
 	 * Last, free the old blocks and assign the new blocks to the buffers.
 	 */
 #ifdef DIAGNOSTIC
 	if (prtrealloc)
 		printf("\n\tnew:");
 #endif
 	for (blkno = newblk, i = 0; i < len; i++, blkno += fs->fs_frag) {
 		bp = buflist->bs_children[i];
 		if (!DOINGSOFTDEP(vp))
 			/*
 			 * The usual case is that a set of N-contiguous blocks
 			 * that was just allocated has been replaced with a
 			 * set of N+1-contiguous blocks. If they are marked as
 			 * B_DELWRI, the current contents have not been written
 			 * to disk. It is possible that the blocks were written
 			 * earlier, but very uncommon. If the blocks have never
 			 * been written, there is no need to send a BIO_DELETE
 			 * for them when they are freed. The gain from avoiding
 			 * the TRIMs for the common case of unwritten blocks
 			 * far exceeds the cost of the write amplification for
 			 * the uncommon case of failing to send a TRIM for the
 			 * blocks that had been written.
 			 */
 			ffs_blkfree(ump, fs, ump->um_devvp,
 			    dbtofsb(fs, bp->b_blkno),
 			    fs->fs_bsize, ip->i_number, vp->v_type, NULL,
 			    (bp->b_flags & B_DELWRI) != 0 ?
 			    NOTRIM_KEY : SINGLETON_KEY);
 		bp->b_blkno = fsbtodb(fs, blkno);
 #ifdef INVARIANTS
 		if (!ffs_checkblk(ip, dbtofsb(fs, bp->b_blkno), fs->fs_bsize))
 			panic("ffs_reallocblks: unallocated block 3");
 #endif
 #ifdef DIAGNOSTIC
 		if (prtrealloc)
 			printf(" %jd,", (intmax_t)blkno);
 #endif
 	}
 #ifdef DIAGNOSTIC
 	if (prtrealloc) {
 		prtrealloc--;
 		printf("\n");
 	}
 #endif
 	return (0);
 
 fail:
 	if (ssize < len)
 		brelse(ebp);
 	if (sbap != &ip->i_din2->di_db[0])
 		brelse(sbp);
 	return (ENOSPC);
 }
 
 /*
  * Allocate an inode in the filesystem.
  *
  * If allocating a directory, use ffs_dirpref to select the inode.
  * If allocating in a directory, the following hierarchy is followed:
  *   1) allocate the preferred inode.
  *   2) allocate an inode in the same cylinder group.
  *   3) quadradically rehash into other cylinder groups, until an
  *      available inode is located.
  * If no inode preference is given the following hierarchy is used
  * to allocate an inode:
  *   1) allocate an inode in cylinder group 0.
  *   2) quadradically rehash into other cylinder groups, until an
  *      available inode is located.
  */
 int
 ffs_valloc(pvp, mode, cred, vpp)
 	struct vnode *pvp;
 	int mode;
 	struct ucred *cred;
 	struct vnode **vpp;
 {
 	struct inode *pip;
 	struct fs *fs;
 	struct inode *ip;
 	struct timespec ts;
 	struct ufsmount *ump;
 	ino_t ino, ipref;
 	u_int cg;
 	int error, reclaimed;
 
 	*vpp = NULL;
 	pip = VTOI(pvp);
 	ump = ITOUMP(pip);
 	fs = ump->um_fs;
 
 	UFS_LOCK(ump);
 	reclaimed = 0;
 retry:
 	if (fs->fs_cstotal.cs_nifree == 0)
 		goto noinodes;
 
 	if ((mode & IFMT) == IFDIR)
 		ipref = ffs_dirpref(pip);
 	else
 		ipref = pip->i_number;
 	if (ipref >= fs->fs_ncg * fs->fs_ipg)
 		ipref = 0;
 	cg = ino_to_cg(fs, ipref);
 	/*
 	 * Track number of dirs created one after another
 	 * in a same cg without intervening by files.
 	 */
 	if ((mode & IFMT) == IFDIR) {
 		if (fs->fs_contigdirs[cg] < 255)
 			fs->fs_contigdirs[cg]++;
 	} else {
 		if (fs->fs_contigdirs[cg] > 0)
 			fs->fs_contigdirs[cg]--;
 	}
 	ino = (ino_t)ffs_hashalloc(pip, cg, ipref, mode, 0,
 					(allocfcn_t *)ffs_nodealloccg);
 	if (ino == 0)
 		goto noinodes;
 	/*
 	 * Get rid of the cached old vnode, force allocation of a new vnode
 	 * for this inode. If this fails, release the allocated ino and
 	 * return the error.
 	 */
 	if ((error = ffs_vgetf(pvp->v_mount, ino, LK_EXCLUSIVE, vpp,
 	    FFSV_FORCEINSMQ | FFSV_REPLACE)) != 0) {
 		ffs_vfree(pvp, ino, mode);
 		return (error);
 	}
 	/*
 	 * We got an inode, so check mode and panic if it is already allocated.
 	 */
 	ip = VTOI(*vpp);
 	if (ip->i_mode) {
 		printf("mode = 0%o, inum = %ju, fs = %s\n",
 		    ip->i_mode, (uintmax_t)ip->i_number, fs->fs_fsmnt);
 		panic("ffs_valloc: dup alloc");
 	}
 	if (DIP(ip, i_blocks) && (fs->fs_flags & FS_UNCLEAN) == 0) {  /* XXX */
 		printf("free inode %s/%lu had %ld blocks\n",
 		    fs->fs_fsmnt, (u_long)ino, (long)DIP(ip, i_blocks));
 		DIP_SET(ip, i_blocks, 0);
 	}
 	ip->i_flags = 0;
 	DIP_SET(ip, i_flags, 0);
 	/*
 	 * Set up a new generation number for this inode.
 	 */
 	while (ip->i_gen == 0 || ++ip->i_gen == 0)
 		ip->i_gen = arc4random();
 	DIP_SET(ip, i_gen, ip->i_gen);
 	if (fs->fs_magic == FS_UFS2_MAGIC) {
 		vfs_timestamp(&ts);
 		ip->i_din2->di_birthtime = ts.tv_sec;
 		ip->i_din2->di_birthnsec = ts.tv_nsec;
 	}
 	ip->i_flag = 0;
 	(*vpp)->v_vflag = 0;
 	(*vpp)->v_type = VNON;
 	if (fs->fs_magic == FS_UFS2_MAGIC) {
 		(*vpp)->v_op = &ffs_vnodeops2;
 		UFS_INODE_SET_FLAG(ip, IN_UFS2);
 	} else {
 		(*vpp)->v_op = &ffs_vnodeops1;
 	}
 	return (0);
 noinodes:
 	if (reclaimed == 0) {
 		reclaimed = 1;
 		softdep_request_cleanup(fs, pvp, cred, FLUSH_INODES_WAIT);
 		goto retry;
 	}
 	if (ffs_fsfail_cleanup_locked(ump, 0)) {
 		UFS_UNLOCK(ump);
 		return (ENXIO);
 	}
 	if (ppsratecheck(&ump->um_last_fullmsg, &ump->um_secs_fullmsg, 1)) {
 		UFS_UNLOCK(ump);
 		ffs_fserr(fs, pip->i_number, "out of inodes");
 		uprintf("\n%s: create/symlink failed, no inodes free\n",
 		    fs->fs_fsmnt);
 	} else {
 		UFS_UNLOCK(ump);
 	}
 	return (ENOSPC);
 }
 
 /*
  * Find a cylinder group to place a directory.
  *
  * The policy implemented by this algorithm is to allocate a
  * directory inode in the same cylinder group as its parent
  * directory, but also to reserve space for its files inodes
  * and data. Restrict the number of directories which may be
  * allocated one after another in the same cylinder group
  * without intervening allocation of files.
  *
  * If we allocate a first level directory then force allocation
  * in another cylinder group.
  */
 static ino_t
 ffs_dirpref(pip)
 	struct inode *pip;
 {
 	struct fs *fs;
 	int cg, prefcg, dirsize, cgsize;
 	u_int avgifree, avgbfree, avgndir, curdirsize;
 	u_int minifree, minbfree, maxndir;
 	u_int mincg, minndir;
 	u_int maxcontigdirs;
 
 	mtx_assert(UFS_MTX(ITOUMP(pip)), MA_OWNED);
 	fs = ITOFS(pip);
 
 	avgifree = fs->fs_cstotal.cs_nifree / fs->fs_ncg;
 	avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
 	avgndir = fs->fs_cstotal.cs_ndir / fs->fs_ncg;
 
 	/*
 	 * Force allocation in another cg if creating a first level dir.
 	 */
 	ASSERT_VOP_LOCKED(ITOV(pip), "ffs_dirpref");
 	if (ITOV(pip)->v_vflag & VV_ROOT) {
 		prefcg = arc4random() % fs->fs_ncg;
 		mincg = prefcg;
 		minndir = fs->fs_ipg;
 		for (cg = prefcg; cg < fs->fs_ncg; cg++)
 			if (fs->fs_cs(fs, cg).cs_ndir < minndir &&
 			    fs->fs_cs(fs, cg).cs_nifree >= avgifree &&
 			    fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
 				mincg = cg;
 				minndir = fs->fs_cs(fs, cg).cs_ndir;
 			}
 		for (cg = 0; cg < prefcg; cg++)
 			if (fs->fs_cs(fs, cg).cs_ndir < minndir &&
 			    fs->fs_cs(fs, cg).cs_nifree >= avgifree &&
 			    fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
 				mincg = cg;
 				minndir = fs->fs_cs(fs, cg).cs_ndir;
 			}
 		return ((ino_t)(fs->fs_ipg * mincg));
 	}
 
 	/*
 	 * Count various limits which used for
 	 * optimal allocation of a directory inode.
 	 */
 	maxndir = min(avgndir + fs->fs_ipg / 16, fs->fs_ipg);
 	minifree = avgifree - avgifree / 4;
 	if (minifree < 1)
 		minifree = 1;
 	minbfree = avgbfree - avgbfree / 4;
 	if (minbfree < 1)
 		minbfree = 1;
 	cgsize = fs->fs_fsize * fs->fs_fpg;
 	dirsize = fs->fs_avgfilesize * fs->fs_avgfpdir;
 	curdirsize = avgndir ? (cgsize - avgbfree * fs->fs_bsize) / avgndir : 0;
 	if (dirsize < curdirsize)
 		dirsize = curdirsize;
 	if (dirsize <= 0)
 		maxcontigdirs = 0;		/* dirsize overflowed */
 	else
 		maxcontigdirs = min((avgbfree * fs->fs_bsize) / dirsize, 255);
 	if (fs->fs_avgfpdir > 0)
 		maxcontigdirs = min(maxcontigdirs,
 				    fs->fs_ipg / fs->fs_avgfpdir);
 	if (maxcontigdirs == 0)
 		maxcontigdirs = 1;
 
 	/*
 	 * Limit number of dirs in one cg and reserve space for 
 	 * regular files, but only if we have no deficit in
 	 * inodes or space.
 	 *
 	 * We are trying to find a suitable cylinder group nearby
 	 * our preferred cylinder group to place a new directory.
 	 * We scan from our preferred cylinder group forward looking
 	 * for a cylinder group that meets our criterion. If we get
 	 * to the final cylinder group and do not find anything,
 	 * we start scanning forwards from the beginning of the
 	 * filesystem. While it might seem sensible to start scanning
 	 * backwards or even to alternate looking forward and backward,
 	 * this approach fails badly when the filesystem is nearly full.
 	 * Specifically, we first search all the areas that have no space
 	 * and finally try the one preceding that. We repeat this on
 	 * every request and in the case of the final block end up
 	 * searching the entire filesystem. By jumping to the front
 	 * of the filesystem, our future forward searches always look
 	 * in new cylinder groups so finds every possible block after
 	 * one pass over the filesystem.
 	 */
 	prefcg = ino_to_cg(fs, pip->i_number);
 	for (cg = prefcg; cg < fs->fs_ncg; cg++)
 		if (fs->fs_cs(fs, cg).cs_ndir < maxndir &&
 		    fs->fs_cs(fs, cg).cs_nifree >= minifree &&
 		    fs->fs_cs(fs, cg).cs_nbfree >= minbfree) {
 			if (fs->fs_contigdirs[cg] < maxcontigdirs)
 				return ((ino_t)(fs->fs_ipg * cg));
 		}
 	for (cg = 0; cg < prefcg; cg++)
 		if (fs->fs_cs(fs, cg).cs_ndir < maxndir &&
 		    fs->fs_cs(fs, cg).cs_nifree >= minifree &&
 		    fs->fs_cs(fs, cg).cs_nbfree >= minbfree) {
 			if (fs->fs_contigdirs[cg] < maxcontigdirs)
 				return ((ino_t)(fs->fs_ipg * cg));
 		}
 	/*
 	 * This is a backstop when we have deficit in space.
 	 */
 	for (cg = prefcg; cg < fs->fs_ncg; cg++)
 		if (fs->fs_cs(fs, cg).cs_nifree >= avgifree)
 			return ((ino_t)(fs->fs_ipg * cg));
 	for (cg = 0; cg < prefcg; cg++)
 		if (fs->fs_cs(fs, cg).cs_nifree >= avgifree)
 			break;
 	return ((ino_t)(fs->fs_ipg * cg));
 }
 
 /*
  * Select the desired position for the next block in a file.  The file is
  * logically divided into sections. The first section is composed of the
  * direct blocks and the next fs_maxbpg blocks. Each additional section
  * contains fs_maxbpg blocks.
  *
  * If no blocks have been allocated in the first section, the policy is to
  * request a block in the same cylinder group as the inode that describes
  * the file. The first indirect is allocated immediately following the last
  * direct block and the data blocks for the first indirect immediately
  * follow it.
  *
  * If no blocks have been allocated in any other section, the indirect 
  * block(s) are allocated in the same cylinder group as its inode in an
  * area reserved immediately following the inode blocks. The policy for
  * the data blocks is to place them in a cylinder group with a greater than
  * average number of free blocks. An appropriate cylinder group is found
  * by using a rotor that sweeps the cylinder groups. When a new group of
  * blocks is needed, the sweep begins in the cylinder group following the
  * cylinder group from which the previous allocation was made. The sweep
  * continues until a cylinder group with greater than the average number
  * of free blocks is found. If the allocation is for the first block in an
  * indirect block or the previous block is a hole, then the information on
  * the previous allocation is unavailable; here a best guess is made based
  * on the logical block number being allocated.
  *
  * If a section is already partially allocated, the policy is to
  * allocate blocks contiguously within the section if possible.
  */
 ufs2_daddr_t
 ffs_blkpref_ufs1(ip, lbn, indx, bap)
 	struct inode *ip;
 	ufs_lbn_t lbn;
 	int indx;
 	ufs1_daddr_t *bap;
 {
 	struct fs *fs;
 	u_int cg, inocg;
 	u_int avgbfree, startcg;
 	ufs2_daddr_t pref, prevbn;
 
 	KASSERT(indx <= 0 || bap != NULL, ("need non-NULL bap"));
 	mtx_assert(UFS_MTX(ITOUMP(ip)), MA_OWNED);
 	fs = ITOFS(ip);
 	/*
 	 * Allocation of indirect blocks is indicated by passing negative
 	 * values in indx: -1 for single indirect, -2 for double indirect,
 	 * -3 for triple indirect. As noted below, we attempt to allocate
 	 * the first indirect inline with the file data. For all later
 	 * indirect blocks, the data is often allocated in other cylinder
 	 * groups. However to speed random file access and to speed up
 	 * fsck, the filesystem reserves the first fs_metaspace blocks
 	 * (typically half of fs_minfree) of the data area of each cylinder
 	 * group to hold these later indirect blocks.
 	 */
 	inocg = ino_to_cg(fs, ip->i_number);
 	if (indx < 0) {
 		/*
 		 * Our preference for indirect blocks is the zone at the
 		 * beginning of the inode's cylinder group data area that
 		 * we try to reserve for indirect blocks.
 		 */
 		pref = cgmeta(fs, inocg);
 		/*
 		 * If we are allocating the first indirect block, try to
 		 * place it immediately following the last direct block.
 		 */
 		if (indx == -1 && lbn < UFS_NDADDR + NINDIR(fs) &&
 		    ip->i_din1->di_db[UFS_NDADDR - 1] != 0)
 			pref = ip->i_din1->di_db[UFS_NDADDR - 1] + fs->fs_frag;
 		return (pref);
 	}
 	/*
 	 * If we are allocating the first data block in the first indirect
 	 * block and the indirect has been allocated in the data block area,
 	 * try to place it immediately following the indirect block.
 	 */
 	if (lbn == UFS_NDADDR) {
 		pref = ip->i_din1->di_ib[0];
 		if (pref != 0 && pref >= cgdata(fs, inocg) &&
 		    pref < cgbase(fs, inocg + 1))
 			return (pref + fs->fs_frag);
 	}
 	/*
 	 * If we are at the beginning of a file, or we have already allocated
 	 * the maximum number of blocks per cylinder group, or we do not
 	 * have a block allocated immediately preceding us, then we need
 	 * to decide where to start allocating new blocks.
 	 */
 	if (indx ==  0) {
 		prevbn = 0;
 	} else {
 		prevbn = bap[indx - 1];
 		if (UFS_CHECK_BLKNO(ITOVFS(ip), ip->i_number, prevbn,
 		    fs->fs_bsize) != 0)
 			prevbn = 0;
 	}
 	if (indx % fs->fs_maxbpg == 0 || prevbn == 0) {
 		/*
 		 * If we are allocating a directory data block, we want
 		 * to place it in the metadata area.
 		 */
 		if ((ip->i_mode & IFMT) == IFDIR)
 			return (cgmeta(fs, inocg));
 		/*
 		 * Until we fill all the direct and all the first indirect's
 		 * blocks, we try to allocate in the data area of the inode's
 		 * cylinder group.
 		 */
 		if (lbn < UFS_NDADDR + NINDIR(fs))
 			return (cgdata(fs, inocg));
 		/*
 		 * Find a cylinder with greater than average number of
 		 * unused data blocks.
 		 */
 		if (indx == 0 || prevbn == 0)
 			startcg = inocg + lbn / fs->fs_maxbpg;
 		else
 			startcg = dtog(fs, prevbn) + 1;
 		startcg %= fs->fs_ncg;
 		avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
 		for (cg = startcg; cg < fs->fs_ncg; cg++)
 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
 				fs->fs_cgrotor = cg;
 				return (cgdata(fs, cg));
 			}
 		for (cg = 0; cg <= startcg; cg++)
 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
 				fs->fs_cgrotor = cg;
 				return (cgdata(fs, cg));
 			}
 		return (0);
 	}
 	/*
 	 * Otherwise, we just always try to lay things out contiguously.
 	 */
 	return (prevbn + fs->fs_frag);
 }
 
 /*
  * Same as above, but for UFS2
  */
 ufs2_daddr_t
 ffs_blkpref_ufs2(ip, lbn, indx, bap)
 	struct inode *ip;
 	ufs_lbn_t lbn;
 	int indx;
 	ufs2_daddr_t *bap;
 {
 	struct fs *fs;
 	u_int cg, inocg;
 	u_int avgbfree, startcg;
 	ufs2_daddr_t pref, prevbn;
 
 	KASSERT(indx <= 0 || bap != NULL, ("need non-NULL bap"));
 	mtx_assert(UFS_MTX(ITOUMP(ip)), MA_OWNED);
 	fs = ITOFS(ip);
 	/*
 	 * Allocation of indirect blocks is indicated by passing negative
 	 * values in indx: -1 for single indirect, -2 for double indirect,
 	 * -3 for triple indirect. As noted below, we attempt to allocate
 	 * the first indirect inline with the file data. For all later
 	 * indirect blocks, the data is often allocated in other cylinder
 	 * groups. However to speed random file access and to speed up
 	 * fsck, the filesystem reserves the first fs_metaspace blocks
 	 * (typically half of fs_minfree) of the data area of each cylinder
 	 * group to hold these later indirect blocks.
 	 */
 	inocg = ino_to_cg(fs, ip->i_number);
 	if (indx < 0) {
 		/*
 		 * Our preference for indirect blocks is the zone at the
 		 * beginning of the inode's cylinder group data area that
 		 * we try to reserve for indirect blocks.
 		 */
 		pref = cgmeta(fs, inocg);
 		/*
 		 * If we are allocating the first indirect block, try to
 		 * place it immediately following the last direct block.
 		 */
 		if (indx == -1 && lbn < UFS_NDADDR + NINDIR(fs) &&
 		    ip->i_din2->di_db[UFS_NDADDR - 1] != 0)
 			pref = ip->i_din2->di_db[UFS_NDADDR - 1] + fs->fs_frag;
 		return (pref);
 	}
 	/*
 	 * If we are allocating the first data block in the first indirect
 	 * block and the indirect has been allocated in the data block area,
 	 * try to place it immediately following the indirect block.
 	 */
 	if (lbn == UFS_NDADDR) {
 		pref = ip->i_din2->di_ib[0];
 		if (pref != 0 && pref >= cgdata(fs, inocg) &&
 		    pref < cgbase(fs, inocg + 1))
 			return (pref + fs->fs_frag);
 	}
 	/*
 	 * If we are at the beginning of a file, or we have already allocated
 	 * the maximum number of blocks per cylinder group, or we do not
 	 * have a block allocated immediately preceding us, then we need
 	 * to decide where to start allocating new blocks.
 	 */
 	if (indx ==  0) {
 		prevbn = 0;
 	} else {
 		prevbn = bap[indx - 1];
 		if (UFS_CHECK_BLKNO(ITOVFS(ip), ip->i_number, prevbn,
 		    fs->fs_bsize) != 0)
 			prevbn = 0;
 	}
 	if (indx % fs->fs_maxbpg == 0 || prevbn == 0) {
 		/*
 		 * If we are allocating a directory data block, we want
 		 * to place it in the metadata area.
 		 */
 		if ((ip->i_mode & IFMT) == IFDIR)
 			return (cgmeta(fs, inocg));
 		/*
 		 * Until we fill all the direct and all the first indirect's
 		 * blocks, we try to allocate in the data area of the inode's
 		 * cylinder group.
 		 */
 		if (lbn < UFS_NDADDR + NINDIR(fs))
 			return (cgdata(fs, inocg));
 		/*
 		 * Find a cylinder with greater than average number of
 		 * unused data blocks.
 		 */
 		if (indx == 0 || prevbn == 0)
 			startcg = inocg + lbn / fs->fs_maxbpg;
 		else
 			startcg = dtog(fs, prevbn) + 1;
 		startcg %= fs->fs_ncg;
 		avgbfree = fs->fs_cstotal.cs_nbfree / fs->fs_ncg;
 		for (cg = startcg; cg < fs->fs_ncg; cg++)
 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
 				fs->fs_cgrotor = cg;
 				return (cgdata(fs, cg));
 			}
 		for (cg = 0; cg <= startcg; cg++)
 			if (fs->fs_cs(fs, cg).cs_nbfree >= avgbfree) {
 				fs->fs_cgrotor = cg;
 				return (cgdata(fs, cg));
 			}
 		return (0);
 	}
 	/*
 	 * Otherwise, we just always try to lay things out contiguously.
 	 */
 	return (prevbn + fs->fs_frag);
 }
 
 /*
  * Implement the cylinder overflow algorithm.
  *
  * The policy implemented by this algorithm is:
  *   1) allocate the block in its requested cylinder group.
  *   2) quadradically rehash on the cylinder group number.
  *   3) brute force search for a free block.
  *
  * Must be called with the UFS lock held.  Will release the lock on success
  * and return with it held on failure.
  */
 /*VARARGS5*/
 static ufs2_daddr_t
 ffs_hashalloc(ip, cg, pref, size, rsize, allocator)
 	struct inode *ip;
 	u_int cg;
 	ufs2_daddr_t pref;
 	int size;	/* Search size for data blocks, mode for inodes */
 	int rsize;	/* Real allocated size. */
 	allocfcn_t *allocator;
 {
 	struct fs *fs;
 	ufs2_daddr_t result;
 	u_int i, icg = cg;
 
 	mtx_assert(UFS_MTX(ITOUMP(ip)), MA_OWNED);
 #ifdef INVARIANTS
 	if (ITOV(ip)->v_mount->mnt_kern_flag & MNTK_SUSPENDED)
 		panic("ffs_hashalloc: allocation on suspended filesystem");
 #endif
 	fs = ITOFS(ip);
 	/*
 	 * 1: preferred cylinder group
 	 */
 	result = (*allocator)(ip, cg, pref, size, rsize);
 	if (result)
 		return (result);
 	/*
 	 * 2: quadratic rehash
 	 */
 	for (i = 1; i < fs->fs_ncg; i *= 2) {
 		cg += i;
 		if (cg >= fs->fs_ncg)
 			cg -= fs->fs_ncg;
 		result = (*allocator)(ip, cg, 0, size, rsize);
 		if (result)
 			return (result);
 	}
 	/*
 	 * 3: brute force search
 	 * Note that we start at i == 2, since 0 was checked initially,
 	 * and 1 is always checked in the quadratic rehash.
 	 */
 	cg = (icg + 2) % fs->fs_ncg;
 	for (i = 2; i < fs->fs_ncg; i++) {
 		result = (*allocator)(ip, cg, 0, size, rsize);
 		if (result)
 			return (result);
 		cg++;
 		if (cg == fs->fs_ncg)
 			cg = 0;
 	}
 	return (0);
 }
 
 /*
  * Determine whether a fragment can be extended.
  *
  * Check to see if the necessary fragments are available, and
  * if they are, allocate them.
  */
 static ufs2_daddr_t
 ffs_fragextend(ip, cg, bprev, osize, nsize)
 	struct inode *ip;
 	u_int cg;
 	ufs2_daddr_t bprev;
 	int osize, nsize;
 {
 	struct fs *fs;
 	struct cg *cgp;
 	struct buf *bp;
 	struct ufsmount *ump;
 	int nffree;
 	long bno;
 	int frags, bbase;
 	int i, error;
 	u_int8_t *blksfree;
 
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	if (fs->fs_cs(fs, cg).cs_nffree < numfrags(fs, nsize - osize))
 		return (0);
 	frags = numfrags(fs, nsize);
 	bbase = fragnum(fs, bprev);
 	if (bbase > fragnum(fs, (bprev + frags - 1))) {
 		/* cannot extend across a block boundary */
 		return (0);
 	}
 	UFS_UNLOCK(ump);
 	if ((error = ffs_getcg(fs, ump->um_devvp, cg, 0, &bp, &cgp)) != 0)
 		goto fail;
 	bno = dtogd(fs, bprev);
 	blksfree = cg_blksfree(cgp);
 	for (i = numfrags(fs, osize); i < frags; i++)
 		if (isclr(blksfree, bno + i))
 			goto fail;
 	/*
 	 * the current fragment can be extended
 	 * deduct the count on fragment being extended into
 	 * increase the count on the remaining fragment (if any)
 	 * allocate the extended piece
 	 */
 	for (i = frags; i < fs->fs_frag - bbase; i++)
 		if (isclr(blksfree, bno + i))
 			break;
 	cgp->cg_frsum[i - numfrags(fs, osize)]--;
 	if (i != frags)
 		cgp->cg_frsum[i - frags]++;
 	for (i = numfrags(fs, osize), nffree = 0; i < frags; i++) {
 		clrbit(blksfree, bno + i);
 		cgp->cg_cs.cs_nffree--;
 		nffree++;
 	}
 	UFS_LOCK(ump);
 	fs->fs_cstotal.cs_nffree -= nffree;
 	fs->fs_cs(fs, cg).cs_nffree -= nffree;
 	fs->fs_fmod = 1;
 	ACTIVECLEAR(fs, cg);
 	UFS_UNLOCK(ump);
 	if (DOINGSOFTDEP(ITOV(ip)))
 		softdep_setup_blkmapdep(bp, UFSTOVFS(ump), bprev,
 		    frags, numfrags(fs, osize));
 	bdwrite(bp);
 	return (bprev);
 
 fail:
 	brelse(bp);
 	UFS_LOCK(ump);
 	return (0);
 
 }
 
 /*
  * Determine whether a block can be allocated.
  *
  * Check to see if a block of the appropriate size is available,
  * and if it is, allocate it.
  */
 static ufs2_daddr_t
 ffs_alloccg(ip, cg, bpref, size, rsize)
 	struct inode *ip;
 	u_int cg;
 	ufs2_daddr_t bpref;
 	int size;
 	int rsize;
 {
 	struct fs *fs;
 	struct cg *cgp;
 	struct buf *bp;
 	struct ufsmount *ump;
 	ufs1_daddr_t bno;
 	ufs2_daddr_t blkno;
 	int i, allocsiz, error, frags;
 	u_int8_t *blksfree;
 
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	if (fs->fs_cs(fs, cg).cs_nbfree == 0 && size == fs->fs_bsize)
 		return (0);
 	UFS_UNLOCK(ump);
 	if ((error = ffs_getcg(fs, ump->um_devvp, cg, 0, &bp, &cgp)) != 0 ||
 	   (cgp->cg_cs.cs_nbfree == 0 && size == fs->fs_bsize))
 		goto fail;
 	if (size == fs->fs_bsize) {
 		UFS_LOCK(ump);
 		blkno = ffs_alloccgblk(ip, bp, bpref, rsize);
 		ACTIVECLEAR(fs, cg);
 		UFS_UNLOCK(ump);
 		bdwrite(bp);
 		return (blkno);
 	}
 	/*
 	 * check to see if any fragments are already available
 	 * allocsiz is the size which will be allocated, hacking
 	 * it down to a smaller size if necessary
 	 */
 	blksfree = cg_blksfree(cgp);
 	frags = numfrags(fs, size);
 	for (allocsiz = frags; allocsiz < fs->fs_frag; allocsiz++)
 		if (cgp->cg_frsum[allocsiz] != 0)
 			break;
 	if (allocsiz == fs->fs_frag) {
 		/*
 		 * no fragments were available, so a block will be
 		 * allocated, and hacked up
 		 */
 		if (cgp->cg_cs.cs_nbfree == 0)
 			goto fail;
 		UFS_LOCK(ump);
 		blkno = ffs_alloccgblk(ip, bp, bpref, rsize);
 		ACTIVECLEAR(fs, cg);
 		UFS_UNLOCK(ump);
 		bdwrite(bp);
 		return (blkno);
 	}
 	KASSERT(size == rsize,
 	    ("ffs_alloccg: size(%d) != rsize(%d)", size, rsize));
 	bno = ffs_mapsearch(fs, cgp, bpref, allocsiz);
 	if (bno < 0)
 		goto fail;
 	for (i = 0; i < frags; i++)
 		clrbit(blksfree, bno + i);
 	cgp->cg_cs.cs_nffree -= frags;
 	cgp->cg_frsum[allocsiz]--;
 	if (frags != allocsiz)
 		cgp->cg_frsum[allocsiz - frags]++;
 	UFS_LOCK(ump);
 	fs->fs_cstotal.cs_nffree -= frags;
 	fs->fs_cs(fs, cg).cs_nffree -= frags;
 	fs->fs_fmod = 1;
 	blkno = cgbase(fs, cg) + bno;
 	ACTIVECLEAR(fs, cg);
 	UFS_UNLOCK(ump);
 	if (DOINGSOFTDEP(ITOV(ip)))
 		softdep_setup_blkmapdep(bp, UFSTOVFS(ump), blkno, frags, 0);
 	bdwrite(bp);
 	return (blkno);
 
 fail:
 	brelse(bp);
 	UFS_LOCK(ump);
 	return (0);
 }
 
 /*
  * Allocate a block in a cylinder group.
  *
  * This algorithm implements the following policy:
  *   1) allocate the requested block.
  *   2) allocate a rotationally optimal block in the same cylinder.
  *   3) allocate the next available block on the block rotor for the
  *      specified cylinder group.
  * Note that this routine only allocates fs_bsize blocks; these
  * blocks may be fragmented by the routine that allocates them.
  */
 static ufs2_daddr_t
 ffs_alloccgblk(ip, bp, bpref, size)
 	struct inode *ip;
 	struct buf *bp;
 	ufs2_daddr_t bpref;
 	int size;
 {
 	struct fs *fs;
 	struct cg *cgp;
 	struct ufsmount *ump;
 	ufs1_daddr_t bno;
 	ufs2_daddr_t blkno;
 	u_int8_t *blksfree;
 	int i, cgbpref;
 
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	mtx_assert(UFS_MTX(ump), MA_OWNED);
 	cgp = (struct cg *)bp->b_data;
 	blksfree = cg_blksfree(cgp);
 	if (bpref == 0) {
 		bpref = cgbase(fs, cgp->cg_cgx) + cgp->cg_rotor + fs->fs_frag;
 	} else if ((cgbpref = dtog(fs, bpref)) != cgp->cg_cgx) {
 		/* map bpref to correct zone in this cg */
 		if (bpref < cgdata(fs, cgbpref))
 			bpref = cgmeta(fs, cgp->cg_cgx);
 		else
 			bpref = cgdata(fs, cgp->cg_cgx);
 	}
 	/*
 	 * if the requested block is available, use it
 	 */
 	bno = dtogd(fs, blknum(fs, bpref));
 	if (ffs_isblock(fs, blksfree, fragstoblks(fs, bno)))
 		goto gotit;
 	/*
 	 * Take the next available block in this cylinder group.
 	 */
 	bno = ffs_mapsearch(fs, cgp, bpref, (int)fs->fs_frag);
 	if (bno < 0)
 		return (0);
 	/* Update cg_rotor only if allocated from the data zone */
 	if (bno >= dtogd(fs, cgdata(fs, cgp->cg_cgx)))
 		cgp->cg_rotor = bno;
 gotit:
 	blkno = fragstoblks(fs, bno);
 	ffs_clrblock(fs, blksfree, (long)blkno);
 	ffs_clusteracct(fs, cgp, blkno, -1);
 	cgp->cg_cs.cs_nbfree--;
 	fs->fs_cstotal.cs_nbfree--;
 	fs->fs_cs(fs, cgp->cg_cgx).cs_nbfree--;
 	fs->fs_fmod = 1;
 	blkno = cgbase(fs, cgp->cg_cgx) + bno;
 	/*
 	 * If the caller didn't want the whole block free the frags here.
 	 */
 	size = numfrags(fs, size);
 	if (size != fs->fs_frag) {
 		bno = dtogd(fs, blkno);
 		for (i = size; i < fs->fs_frag; i++)
 			setbit(blksfree, bno + i);
 		i = fs->fs_frag - size;
 		cgp->cg_cs.cs_nffree += i;
 		fs->fs_cstotal.cs_nffree += i;
 		fs->fs_cs(fs, cgp->cg_cgx).cs_nffree += i;
 		fs->fs_fmod = 1;
 		cgp->cg_frsum[i]++;
 	}
 	/* XXX Fixme. */
 	UFS_UNLOCK(ump);
 	if (DOINGSOFTDEP(ITOV(ip)))
 		softdep_setup_blkmapdep(bp, UFSTOVFS(ump), blkno, size, 0);
 	UFS_LOCK(ump);
 	return (blkno);
 }
 
 /*
  * Determine whether a cluster can be allocated.
  *
  * We do not currently check for optimal rotational layout if there
  * are multiple choices in the same cylinder group. Instead we just
  * take the first one that we find following bpref.
  */
 static ufs2_daddr_t
 ffs_clusteralloc(ip, cg, bpref, len)
 	struct inode *ip;
 	u_int cg;
 	ufs2_daddr_t bpref;
 	int len;
 {
 	struct fs *fs;
 	struct cg *cgp;
 	struct buf *bp;
 	struct ufsmount *ump;
 	int i, run, bit, map, got, error;
 	ufs2_daddr_t bno;
 	u_char *mapp;
 	int32_t *lp;
 	u_int8_t *blksfree;
 
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 	if (fs->fs_maxcluster[cg] < len)
 		return (0);
 	UFS_UNLOCK(ump);
 	if ((error = ffs_getcg(fs, ump->um_devvp, cg, 0, &bp, &cgp)) != 0) {
 		UFS_LOCK(ump);
 		return (0);
 	}
 	/*
 	 * Check to see if a cluster of the needed size (or bigger) is
 	 * available in this cylinder group.
 	 */
 	lp = &cg_clustersum(cgp)[len];
 	for (i = len; i <= fs->fs_contigsumsize; i++)
 		if (*lp++ > 0)
 			break;
 	if (i > fs->fs_contigsumsize) {
 		/*
 		 * This is the first time looking for a cluster in this
 		 * cylinder group. Update the cluster summary information
 		 * to reflect the true maximum sized cluster so that
 		 * future cluster allocation requests can avoid reading
 		 * the cylinder group map only to find no clusters.
 		 */
 		lp = &cg_clustersum(cgp)[len - 1];
 		for (i = len - 1; i > 0; i--)
 			if (*lp-- > 0)
 				break;
 		UFS_LOCK(ump);
 		fs->fs_maxcluster[cg] = i;
 		brelse(bp);
 		return (0);
 	}
 	/*
 	 * Search the cluster map to find a big enough cluster.
 	 * We take the first one that we find, even if it is larger
 	 * than we need as we prefer to get one close to the previous
 	 * block allocation. We do not search before the current
 	 * preference point as we do not want to allocate a block
 	 * that is allocated before the previous one (as we will
 	 * then have to wait for another pass of the elevator
 	 * algorithm before it will be read). We prefer to fail and
 	 * be recalled to try an allocation in the next cylinder group.
 	 */
 	if (dtog(fs, bpref) != cg)
 		bpref = cgdata(fs, cg);
 	else
 		bpref = blknum(fs, bpref);
 	bpref = fragstoblks(fs, dtogd(fs, bpref));
 	mapp = &cg_clustersfree(cgp)[bpref / NBBY];
 	map = *mapp++;
 	bit = 1 << (bpref % NBBY);
 	for (run = 0, got = bpref; got < cgp->cg_nclusterblks; got++) {
 		if ((map & bit) == 0) {
 			run = 0;
 		} else {
 			run++;
 			if (run == len)
 				break;
 		}
 		if ((got & (NBBY - 1)) != (NBBY - 1)) {
 			bit <<= 1;
 		} else {
 			map = *mapp++;
 			bit = 1;
 		}
 	}
 	if (got >= cgp->cg_nclusterblks) {
 		UFS_LOCK(ump);
 		brelse(bp);
 		return (0);
 	}
 	/*
 	 * Allocate the cluster that we have found.
 	 */
 	blksfree = cg_blksfree(cgp);
 	for (i = 1; i <= len; i++)
 		if (!ffs_isblock(fs, blksfree, got - run + i))
 			panic("ffs_clusteralloc: map mismatch");
 	bno = cgbase(fs, cg) + blkstofrags(fs, got - run + 1);
 	if (dtog(fs, bno) != cg)
 		panic("ffs_clusteralloc: allocated out of group");
 	len = blkstofrags(fs, len);
 	UFS_LOCK(ump);
 	for (i = 0; i < len; i += fs->fs_frag)
 		if (ffs_alloccgblk(ip, bp, bno + i, fs->fs_bsize) != bno + i)
 			panic("ffs_clusteralloc: lost block");
 	ACTIVECLEAR(fs, cg);
 	UFS_UNLOCK(ump);
 	bdwrite(bp);
 	return (bno);
 }
 
 static inline struct buf *
 getinobuf(struct inode *ip, u_int cg, u_int32_t cginoblk, int gbflags)
 {
 	struct fs *fs;
 
 	fs = ITOFS(ip);
 	return (getblk(ITODEVVP(ip), fsbtodb(fs, ino_to_fsba(fs,
 	    cg * fs->fs_ipg + cginoblk)), (int)fs->fs_bsize, 0, 0,
 	    gbflags));
 }
 
 /*
  * Synchronous inode initialization is needed only when barrier writes do not
  * work as advertised, and will impose a heavy cost on file creation in a newly
  * created filesystem.
  */
 static int doasyncinodeinit = 1;
 SYSCTL_INT(_vfs_ffs, OID_AUTO, doasyncinodeinit, CTLFLAG_RWTUN,
     &doasyncinodeinit, 0,
     "Perform inode block initialization using asynchronous writes");
 
 /*
  * Determine whether an inode can be allocated.
  *
  * Check to see if an inode is available, and if it is,
  * allocate it using the following policy:
  *   1) allocate the requested inode.
  *   2) allocate the next available inode after the requested
  *      inode in the specified cylinder group.
  */
 static ufs2_daddr_t
 ffs_nodealloccg(ip, cg, ipref, mode, unused)
 	struct inode *ip;
 	u_int cg;
 	ufs2_daddr_t ipref;
 	int mode;
 	int unused;
 {
 	struct fs *fs;
 	struct cg *cgp;
 	struct buf *bp, *ibp;
 	struct ufsmount *ump;
 	u_int8_t *inosused, *loc;
 	struct ufs2_dinode *dp2;
 	int error, start, len, i;
 	u_int32_t old_initediblk;
 
 	ump = ITOUMP(ip);
 	fs = ump->um_fs;
 check_nifree:
 	if (fs->fs_cs(fs, cg).cs_nifree == 0)
 		return (0);
 	UFS_UNLOCK(ump);
 	if ((error = ffs_getcg(fs, ump->um_devvp, cg, 0, &bp, &cgp)) != 0) {
 		UFS_LOCK(ump);
 		return (0);
 	}
 restart:
 	if (cgp->cg_cs.cs_nifree == 0) {
 		brelse(bp);
 		UFS_LOCK(ump);
 		return (0);
 	}
 	inosused = cg_inosused(cgp);
 	if (ipref) {
 		ipref %= fs->fs_ipg;
 		if (isclr(inosused, ipref))
 			goto gotit;
 	}
 	start = cgp->cg_irotor / NBBY;
 	len = howmany(fs->fs_ipg - cgp->cg_irotor, NBBY);
 	loc = memcchr(&inosused[start], 0xff, len);
 	if (loc == NULL) {
 		len = start + 1;
 		start = 0;
 		loc = memcchr(&inosused[start], 0xff, len);
 		if (loc == NULL) {
 			printf("cg = %d, irotor = %ld, fs = %s\n",
 			    cg, (long)cgp->cg_irotor, fs->fs_fsmnt);
 			panic("ffs_nodealloccg: map corrupted");
 			/* NOTREACHED */
 		}
 	}
 	ipref = (loc - inosused) * NBBY + ffs(~*loc) - 1;
 gotit:
 	/*
 	 * Check to see if we need to initialize more inodes.
 	 */
 	if (fs->fs_magic == FS_UFS2_MAGIC &&
 	    ipref + INOPB(fs) > cgp->cg_initediblk &&
 	    cgp->cg_initediblk < cgp->cg_niblk) {
 		old_initediblk = cgp->cg_initediblk;
 
 		/*
 		 * Free the cylinder group lock before writing the
 		 * initialized inode block.  Entering the
 		 * babarrierwrite() with the cylinder group lock
 		 * causes lock order violation between the lock and
 		 * snaplk.
 		 *
 		 * Another thread can decide to initialize the same
 		 * inode block, but whichever thread first gets the
 		 * cylinder group lock after writing the newly
 		 * allocated inode block will update it and the other
 		 * will realize that it has lost and leave the
 		 * cylinder group unchanged.
 		 */
 		ibp = getinobuf(ip, cg, old_initediblk, GB_LOCK_NOWAIT);
 		brelse(bp);
 		if (ibp == NULL) {
 			/*
 			 * The inode block buffer is already owned by
 			 * another thread, which must initialize it.
 			 * Wait on the buffer to allow another thread
 			 * to finish the updates, with dropped cg
 			 * buffer lock, then retry.
 			 */
 			ibp = getinobuf(ip, cg, old_initediblk, 0);
 			brelse(ibp);
 			UFS_LOCK(ump);
 			goto check_nifree;
 		}
 		bzero(ibp->b_data, (int)fs->fs_bsize);
 		dp2 = (struct ufs2_dinode *)(ibp->b_data);
 		for (i = 0; i < INOPB(fs); i++) {
 			while (dp2->di_gen == 0)
 				dp2->di_gen = arc4random();
 			dp2++;
 		}
 
 		/*
 		 * Rather than adding a soft updates dependency to ensure
 		 * that the new inode block is written before it is claimed
 		 * by the cylinder group map, we just do a barrier write
 		 * here. The barrier write will ensure that the inode block
 		 * gets written before the updated cylinder group map can be
 		 * written. The barrier write should only slow down bulk
 		 * loading of newly created filesystems.
 		 */
 		if (doasyncinodeinit)
 			babarrierwrite(ibp);
 		else
 			bwrite(ibp);
 
 		/*
 		 * After the inode block is written, try to update the
 		 * cg initediblk pointer.  If another thread beat us
 		 * to it, then leave it unchanged as the other thread
 		 * has already set it correctly.
 		 */
 		error = ffs_getcg(fs, ump->um_devvp, cg, 0, &bp, &cgp);
 		UFS_LOCK(ump);
 		ACTIVECLEAR(fs, cg);
 		UFS_UNLOCK(ump);
 		if (error != 0)
 			return (error);
 		if (cgp->cg_initediblk == old_initediblk)
 			cgp->cg_initediblk += INOPB(fs);
 		goto restart;
 	}
 	cgp->cg_irotor = ipref;
 	UFS_LOCK(ump);
 	ACTIVECLEAR(fs, cg);
 	setbit(inosused, ipref);
 	cgp->cg_cs.cs_nifree--;
 	fs->fs_cstotal.cs_nifree--;
 	fs->fs_cs(fs, cg).cs_nifree--;
 	fs->fs_fmod = 1;
 	if ((mode & IFMT) == IFDIR) {
 		cgp->cg_cs.cs_ndir++;
 		fs->fs_cstotal.cs_ndir++;
 		fs->fs_cs(fs, cg).cs_ndir++;
 	}
 	UFS_UNLOCK(ump);
 	if (DOINGSOFTDEP(ITOV(ip)))
 		softdep_setup_inomapdep(bp, ip, cg * fs->fs_ipg + ipref, mode);
 	bdwrite(bp);
 	return ((ino_t)(cg * fs->fs_ipg + ipref));
 }
 
 /*
  * Free a block or fragment.
  *
  * The specified block or fragment is placed back in the
  * free map. If a fragment is deallocated, a possible
  * block reassembly is checked.
  */
 static void
 ffs_blkfree_cg(ump, fs, devvp, bno, size, inum, dephd)
 	struct ufsmount *ump;
 	struct fs *fs;
 	struct vnode *devvp;
 	ufs2_daddr_t bno;
 	long size;
 	ino_t inum;
 	struct workhead *dephd;
 {
 	struct mount *mp;
 	struct cg *cgp;
 	struct buf *bp;
 	daddr_t dbn;
 	ufs1_daddr_t fragno, cgbno;
 	int i, blk, frags, bbase, error;
 	u_int cg;
 	u_int8_t *blksfree;
 	struct cdev *dev;
 
 	cg = dtog(fs, bno);
 	if (devvp->v_type == VREG) {
 		/* devvp is a snapshot */
 		MPASS(devvp->v_mount->mnt_data == ump);
 		dev = ump->um_devvp->v_rdev;
 	} else if (devvp->v_type == VCHR) {
 		/* devvp is a normal disk device */
 		dev = devvp->v_rdev;
 		ASSERT_VOP_LOCKED(devvp, "ffs_blkfree_cg");
 	} else
 		return;
 #ifdef INVARIANTS
 	if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0 ||
 	    fragnum(fs, bno) + numfrags(fs, size) > fs->fs_frag) {
 		printf("dev=%s, bno = %jd, bsize = %ld, size = %ld, fs = %s\n",
 		    devtoname(dev), (intmax_t)bno, (long)fs->fs_bsize,
 		    size, fs->fs_fsmnt);
 		panic("ffs_blkfree_cg: bad size");
 	}
 #endif
 	if ((u_int)bno >= fs->fs_size) {
 		printf("bad block %jd, ino %lu\n", (intmax_t)bno,
 		    (u_long)inum);
 		ffs_fserr(fs, inum, "bad block");
 		return;
 	}
 	if ((error = ffs_getcg(fs, devvp, cg, GB_CVTENXIO, &bp, &cgp)) != 0) {
 		if (!ffs_fsfail_cleanup(ump, error) ||
 		    !MOUNTEDSOFTDEP(UFSTOVFS(ump)) || devvp->v_type != VCHR)
 			return;
 		if (devvp->v_type == VREG)
 			dbn = fragstoblks(fs, cgtod(fs, cg));
 		else
 			dbn = fsbtodb(fs, cgtod(fs, cg));
 		error = getblkx(devvp, dbn, dbn, fs->fs_cgsize, 0, 0, 0, &bp);
 		KASSERT(error == 0, ("getblkx failed"));
 		softdep_setup_blkfree(UFSTOVFS(ump), bp, bno,
 		    numfrags(fs, size), dephd);
 		bp->b_flags |= B_RELBUF | B_NOCACHE;
 		bp->b_flags &= ~B_CACHE;
 		bawrite(bp);
 		return;
 	}
 	cgbno = dtogd(fs, bno);
 	blksfree = cg_blksfree(cgp);
 	UFS_LOCK(ump);
 	if (size == fs->fs_bsize) {
 		fragno = fragstoblks(fs, cgbno);
 		if (!ffs_isfreeblock(fs, blksfree, fragno)) {
 			if (devvp->v_type == VREG) {
 				UFS_UNLOCK(ump);
 				/* devvp is a snapshot */
 				brelse(bp);
 				return;
 			}
 			printf("dev = %s, block = %jd, fs = %s\n",
 			    devtoname(dev), (intmax_t)bno, fs->fs_fsmnt);
 			panic("ffs_blkfree_cg: freeing free block");
 		}
 		ffs_setblock(fs, blksfree, fragno);
 		ffs_clusteracct(fs, cgp, fragno, 1);
 		cgp->cg_cs.cs_nbfree++;
 		fs->fs_cstotal.cs_nbfree++;
 		fs->fs_cs(fs, cg).cs_nbfree++;
 	} else {
 		bbase = cgbno - fragnum(fs, cgbno);
 		/*
 		 * decrement the counts associated with the old frags
 		 */
 		blk = blkmap(fs, blksfree, bbase);
 		ffs_fragacct(fs, blk, cgp->cg_frsum, -1);
 		/*
 		 * deallocate the fragment
 		 */
 		frags = numfrags(fs, size);
 		for (i = 0; i < frags; i++) {
 			if (isset(blksfree, cgbno + i)) {
 				printf("dev = %s, block = %jd, fs = %s\n",
 				    devtoname(dev), (intmax_t)(bno + i),
 				    fs->fs_fsmnt);
 				panic("ffs_blkfree_cg: freeing free frag");
 			}
 			setbit(blksfree, cgbno + i);
 		}
 		cgp->cg_cs.cs_nffree += i;
 		fs->fs_cstotal.cs_nffree += i;
 		fs->fs_cs(fs, cg).cs_nffree += i;
 		/*
 		 * add back in counts associated with the new frags
 		 */
 		blk = blkmap(fs, blksfree, bbase);
 		ffs_fragacct(fs, blk, cgp->cg_frsum, 1);
 		/*
 		 * if a complete block has been reassembled, account for it
 		 */
 		fragno = fragstoblks(fs, bbase);
 		if (ffs_isblock(fs, blksfree, fragno)) {
 			cgp->cg_cs.cs_nffree -= fs->fs_frag;
 			fs->fs_cstotal.cs_nffree -= fs->fs_frag;
 			fs->fs_cs(fs, cg).cs_nffree -= fs->fs_frag;
 			ffs_clusteracct(fs, cgp, fragno, 1);
 			cgp->cg_cs.cs_nbfree++;
 			fs->fs_cstotal.cs_nbfree++;
 			fs->fs_cs(fs, cg).cs_nbfree++;
 		}
 	}
 	fs->fs_fmod = 1;
 	ACTIVECLEAR(fs, cg);
 	UFS_UNLOCK(ump);
 	mp = UFSTOVFS(ump);
 	if (MOUNTEDSOFTDEP(mp) && devvp->v_type == VCHR)
 		softdep_setup_blkfree(UFSTOVFS(ump), bp, bno,
 		    numfrags(fs, size), dephd);
 	bdwrite(bp);
 }
 
 /*
  * Structures and routines associated with trim management.
  *
  * The following requests are passed to trim_lookup to indicate
  * the actions that should be taken.
  */
 #define	NEW	1	/* if found, error else allocate and hash it */
 #define	OLD	2	/* if not found, error, else return it */
 #define	REPLACE	3	/* if not found, error else unhash and reallocate it */
 #define	DONE	4	/* if not found, error else unhash and return it */
 #define	SINGLE	5	/* don't look up, just allocate it and don't hash it */
 
 MALLOC_DEFINE(M_TRIM, "ufs_trim", "UFS trim structures");
 
 #define	TRIMLIST_HASH(ump, key) \
 	(&(ump)->um_trimhash[(key) & (ump)->um_trimlisthashsize])
 
 /*
  * These structures describe each of the block free requests aggregated
  * together to make up a trim request.
  */
 struct trim_blkreq {
 	TAILQ_ENTRY(trim_blkreq) blkreqlist;
 	ufs2_daddr_t bno;
 	long size;
 	struct workhead *pdephd;
 	struct workhead dephd;
 };
 
 /*
  * Description of a trim request.
  */
 struct ffs_blkfree_trim_params {
 	TAILQ_HEAD(, trim_blkreq) blklist;
 	LIST_ENTRY(ffs_blkfree_trim_params) hashlist;
 	struct task task;
 	struct ufsmount *ump;
 	struct vnode *devvp;
 	ino_t inum;
 	ufs2_daddr_t bno;
 	long size;
 	long key;
 };
 
 static void	ffs_blkfree_trim_completed(struct buf *);
 static void	ffs_blkfree_trim_task(void *ctx, int pending __unused);
 static struct	ffs_blkfree_trim_params *trim_lookup(struct ufsmount *,
 		    struct vnode *, ufs2_daddr_t, long, ino_t, u_long, int);
 static void	ffs_blkfree_sendtrim(struct ffs_blkfree_trim_params *);
 
 /*
  * Called on trim completion to start a task to free the associated block(s).
  */
 static void
 ffs_blkfree_trim_completed(bp)
 	struct buf *bp;
 {
 	struct ffs_blkfree_trim_params *tp;
 
 	tp = bp->b_fsprivate1;
 	free(bp, M_TRIM);
 	TASK_INIT(&tp->task, 0, ffs_blkfree_trim_task, tp);
 	taskqueue_enqueue(tp->ump->um_trim_tq, &tp->task);
 }
 
 /*
  * Trim completion task that free associated block(s).
  */
 static void
 ffs_blkfree_trim_task(ctx, pending)
 	void *ctx;
 	int pending;
 {
 	struct ffs_blkfree_trim_params *tp;
 	struct trim_blkreq *blkelm;
 	struct ufsmount *ump;
 
 	tp = ctx;
 	ump = tp->ump;
 	while ((blkelm = TAILQ_FIRST(&tp->blklist)) != NULL) {
 		ffs_blkfree_cg(ump, ump->um_fs, tp->devvp, blkelm->bno,
 		    blkelm->size, tp->inum, blkelm->pdephd);
 		TAILQ_REMOVE(&tp->blklist, blkelm, blkreqlist);
 		free(blkelm, M_TRIM);
 	}
 	vn_finished_secondary_write(UFSTOVFS(ump));
 	UFS_LOCK(ump);
 	ump->um_trim_inflight -= 1;
 	ump->um_trim_inflight_blks -= numfrags(ump->um_fs, tp->size);
 	UFS_UNLOCK(ump);
 	free(tp, M_TRIM);
 }
 
 /*
  * Lookup a trim request by inode number.
  * Allocate if requested (NEW, REPLACE, SINGLE).
  */
 static struct ffs_blkfree_trim_params *
 trim_lookup(ump, devvp, bno, size, inum, key, alloctype)
 	struct ufsmount *ump;
 	struct vnode *devvp;
 	ufs2_daddr_t bno;
 	long size;
 	ino_t inum;
 	u_long key;
 	int alloctype;
 {
 	struct trimlist_hashhead *tphashhead;
 	struct ffs_blkfree_trim_params *tp, *ntp;
 
 	ntp = malloc(sizeof(struct ffs_blkfree_trim_params), M_TRIM, M_WAITOK);
 	if (alloctype != SINGLE) {
 		KASSERT(key >= FIRST_VALID_KEY, ("trim_lookup: invalid key"));
 		UFS_LOCK(ump);
 		tphashhead = TRIMLIST_HASH(ump, key);
 		LIST_FOREACH(tp, tphashhead, hashlist)
 			if (key == tp->key)
 				break;
 	}
 	switch (alloctype) {
 	case NEW:
 		KASSERT(tp == NULL, ("trim_lookup: found trim"));
 		break;
 	case OLD:
 		KASSERT(tp != NULL,
 		    ("trim_lookup: missing call to ffs_blkrelease_start()"));
 		UFS_UNLOCK(ump);
 		free(ntp, M_TRIM);
 		return (tp);
 	case REPLACE:
 		KASSERT(tp != NULL, ("trim_lookup: missing REPLACE trim"));
 		LIST_REMOVE(tp, hashlist);
 		/* tp will be freed by caller */
 		break;
 	case DONE:
 		KASSERT(tp != NULL, ("trim_lookup: missing DONE trim"));
 		LIST_REMOVE(tp, hashlist);
 		UFS_UNLOCK(ump);
 		free(ntp, M_TRIM);
 		return (tp);
 	}
 	TAILQ_INIT(&ntp->blklist);
 	ntp->ump = ump;
 	ntp->devvp = devvp;
 	ntp->bno = bno;
 	ntp->size = size;
 	ntp->inum = inum;
 	ntp->key = key;
 	if (alloctype != SINGLE) {
 		LIST_INSERT_HEAD(tphashhead, ntp, hashlist);
 		UFS_UNLOCK(ump);
 	}
 	return (ntp);
 }
 
 /*
  * Dispatch a trim request.
  */
 static void
 ffs_blkfree_sendtrim(tp)
 	struct ffs_blkfree_trim_params *tp;
 {
 	struct ufsmount *ump;
 	struct mount *mp;
 	struct buf *bp;
 
 	/*
 	 * Postpone the set of the free bit in the cg bitmap until the
 	 * BIO_DELETE is completed.  Otherwise, due to disk queue
 	 * reordering, TRIM might be issued after we reuse the block
 	 * and write some new data into it.
 	 */
 	ump = tp->ump;
 	bp = malloc(sizeof(*bp), M_TRIM, M_WAITOK | M_ZERO);
 	bp->b_iocmd = BIO_DELETE;
 	bp->b_iooffset = dbtob(fsbtodb(ump->um_fs, tp->bno));
 	bp->b_iodone = ffs_blkfree_trim_completed;
 	bp->b_bcount = tp->size;
 	bp->b_fsprivate1 = tp;
 	UFS_LOCK(ump);
 	ump->um_trim_total += 1;
 	ump->um_trim_inflight += 1;
 	ump->um_trim_inflight_blks += numfrags(ump->um_fs, tp->size);
 	ump->um_trim_total_blks += numfrags(ump->um_fs, tp->size);
 	UFS_UNLOCK(ump);
 
 	mp = UFSTOVFS(ump);
 	vn_start_secondary_write(NULL, &mp, 0);
 	g_vfs_strategy(ump->um_bo, bp);
 }
 
 /*
  * Allocate a new key to use to identify a range of blocks.
  */
 u_long
 ffs_blkrelease_start(ump, devvp, inum)
 	struct ufsmount *ump;
 	struct vnode *devvp;
 	ino_t inum;
 {
 	static u_long masterkey;
 	u_long key;
 
 	if (((ump->um_flags & UM_CANDELETE) == 0) || dotrimcons == 0)
 		return (SINGLETON_KEY);
 	do {
 		key = atomic_fetchadd_long(&masterkey, 1);
 	} while (key < FIRST_VALID_KEY);
 	(void) trim_lookup(ump, devvp, 0, 0, inum, key, NEW);
 	return (key);
 }
 
 /*
  * Deallocate a key that has been used to identify a range of blocks.
  */
 void
 ffs_blkrelease_finish(ump, key)
 	struct ufsmount *ump;
 	u_long key;
 {
 	struct ffs_blkfree_trim_params *tp;
 
 	if (((ump->um_flags & UM_CANDELETE) == 0) || dotrimcons == 0)
 		return;
 	/*
 	 * If the vfs.ffs.dotrimcons sysctl option is enabled while
 	 * a file deletion is active, specifically after a call
 	 * to ffs_blkrelease_start() but before the call to
 	 * ffs_blkrelease_finish(), ffs_blkrelease_start() will
 	 * have handed out SINGLETON_KEY rather than starting a
 	 * collection sequence. Thus if we get a SINGLETON_KEY
 	 * passed to ffs_blkrelease_finish(), we just return rather
 	 * than trying to finish the nonexistent sequence.
 	 */
 	if (key == SINGLETON_KEY) {
 #ifdef INVARIANTS
 		printf("%s: vfs.ffs.dotrimcons enabled on active filesystem\n",
 		    ump->um_mountp->mnt_stat.f_mntonname);
 #endif
 		return;
 	}
 	/*
 	 * We are done with sending blocks using this key. Look up the key
 	 * using the DONE alloctype (in tp) to request that it be unhashed
 	 * as we will not be adding to it. If the key has never been used,
 	 * tp->size will be zero, so we can just free tp. Otherwise the call
 	 * to ffs_blkfree_sendtrim(tp) causes the block range described by
 	 * tp to be issued (and then tp to be freed).
 	 */
 	tp = trim_lookup(ump, NULL, 0, 0, 0, key, DONE);
 	if (tp->size == 0)
 		free(tp, M_TRIM);
 	else
 		ffs_blkfree_sendtrim(tp);
 }
 
 /*
  * Setup to free a block or fragment.
  *
  * Check for snapshots that might want to claim the block.
  * If trims are requested, prepare a trim request. Attempt to
  * aggregate consecutive blocks into a single trim request.
  */
 void
 ffs_blkfree(ump, fs, devvp, bno, size, inum, vtype, dephd, key)
 	struct ufsmount *ump;
 	struct fs *fs;
 	struct vnode *devvp;
 	ufs2_daddr_t bno;
 	long size;
 	ino_t inum;
 	enum vtype vtype;
 	struct workhead *dephd;
 	u_long key;
 {
 	struct ffs_blkfree_trim_params *tp, *ntp;
 	struct trim_blkreq *blkelm;
 
 	/*
 	 * Check to see if a snapshot wants to claim the block.
 	 * Check that devvp is a normal disk device, not a snapshot,
 	 * it has a snapshot(s) associated with it, and one of the
 	 * snapshots wants to claim the block.
 	 */
 	if (devvp->v_type == VCHR &&
 	    (devvp->v_vflag & VV_COPYONWRITE) &&
 	    ffs_snapblkfree(fs, devvp, bno, size, inum, vtype, dephd)) {
 		return;
 	}
 	/*
 	 * Nothing to delay if TRIM is not required for this block or TRIM
 	 * is disabled or the operation is performed on a snapshot.
 	 */
 	if (key == NOTRIM_KEY || ((ump->um_flags & UM_CANDELETE) == 0) ||
 	    devvp->v_type == VREG) {
 		ffs_blkfree_cg(ump, fs, devvp, bno, size, inum, dephd);
 		return;
 	}
 	blkelm = malloc(sizeof(struct trim_blkreq), M_TRIM, M_WAITOK);
 	blkelm->bno = bno;
 	blkelm->size = size;
 	if (dephd == NULL) {
 		blkelm->pdephd = NULL;
 	} else {
 		LIST_INIT(&blkelm->dephd);
 		LIST_SWAP(dephd, &blkelm->dephd, worklist, wk_list);
 		blkelm->pdephd = &blkelm->dephd;
 	}
 	if (key == SINGLETON_KEY) {
 		/*
 		 * Just a single non-contiguous piece. Use the SINGLE
 		 * alloctype to return a trim request that will not be
 		 * hashed for future lookup.
 		 */
 		tp = trim_lookup(ump, devvp, bno, size, inum, key, SINGLE);
 		TAILQ_INSERT_HEAD(&tp->blklist, blkelm, blkreqlist);
 		ffs_blkfree_sendtrim(tp);
 		return;
 	}
 	/*
 	 * The callers of this function are not tracking whether or not
 	 * the blocks are contiguous. They are just saying that they
 	 * are freeing a set of blocks. It is this code that determines
 	 * the pieces of that range that are actually contiguous.
 	 *
 	 * Calling ffs_blkrelease_start() will have created an entry
 	 * that we will use.
 	 */
 	tp = trim_lookup(ump, devvp, bno, size, inum, key, OLD);
 	if (tp->size == 0) {
 		/*
 		 * First block of a potential range, set block and size
 		 * for the trim block.
 		 */
 		tp->bno = bno;
 		tp->size = size;
 		TAILQ_INSERT_HEAD(&tp->blklist, blkelm, blkreqlist);
 		return;
 	}
 	/*
 	 * If this block is a continuation of the range (either
 	 * follows at the end or preceeds in the front) then we
 	 * add it to the front or back of the list and return.
 	 *
 	 * If it is not a continuation of the trim that we were
 	 * building, using the REPLACE alloctype, we request that
 	 * the old trim request (still in tp) be unhashed and a
 	 * new range started (in ntp). The ffs_blkfree_sendtrim(tp)
 	 * call causes the block range described by tp to be issued
 	 * (and then tp to be freed).
 	 */
 	if (bno + numfrags(fs, size) == tp->bno) {
 		TAILQ_INSERT_HEAD(&tp->blklist, blkelm, blkreqlist);
 		tp->bno = bno;
 		tp->size += size;
 		return;
 	} else if (bno == tp->bno + numfrags(fs, tp->size)) {
 		TAILQ_INSERT_TAIL(&tp->blklist, blkelm, blkreqlist);
 		tp->size += size;
 		return;
 	}
 	ntp = trim_lookup(ump, devvp, bno, size, inum, key, REPLACE);
 	TAILQ_INSERT_HEAD(&ntp->blklist, blkelm, blkreqlist);
 	ffs_blkfree_sendtrim(tp);
 }
 
 #ifdef INVARIANTS
 /*
  * Verify allocation of a block or fragment. Returns true if block or
  * fragment is allocated, false if it is free.
  */
 static int
 ffs_checkblk(ip, bno, size)
 	struct inode *ip;
 	ufs2_daddr_t bno;
 	long size;
 {
 	struct fs *fs;
 	struct cg *cgp;
 	struct buf *bp;
 	ufs1_daddr_t cgbno;
 	int i, error, frags, free;
 	u_int8_t *blksfree;
 
 	fs = ITOFS(ip);
 	if ((u_int)size > fs->fs_bsize || fragoff(fs, size) != 0) {
 		printf("bsize = %ld, size = %ld, fs = %s\n",
 		    (long)fs->fs_bsize, size, fs->fs_fsmnt);
 		panic("ffs_checkblk: bad size");
 	}
 	if ((u_int)bno >= fs->fs_size)
 		panic("ffs_checkblk: bad block %jd", (intmax_t)bno);
 	error = ffs_getcg(fs, ITODEVVP(ip), dtog(fs, bno), 0, &bp, &cgp);
 	if (error)
 		panic("ffs_checkblk: cylinder group read failed");
 	blksfree = cg_blksfree(cgp);
 	cgbno = dtogd(fs, bno);
 	if (size == fs->fs_bsize) {
 		free = ffs_isblock(fs, blksfree, fragstoblks(fs, cgbno));
 	} else {
 		frags = numfrags(fs, size);
 		for (free = 0, i = 0; i < frags; i++)
 			if (isset(blksfree, cgbno + i))
 				free++;
 		if (free != 0 && free != frags)
 			panic("ffs_checkblk: partially free fragment");
 	}
 	brelse(bp);
 	return (!free);
 }
 #endif /* INVARIANTS */
 
 /*
  * Free an inode.
  */
 int
 ffs_vfree(pvp, ino, mode)
 	struct vnode *pvp;
 	ino_t ino;
 	int mode;
 {
 	struct ufsmount *ump;
 
 	if (DOINGSOFTDEP(pvp)) {
 		softdep_freefile(pvp, ino, mode);
 		return (0);
 	}
 	ump = VFSTOUFS(pvp->v_mount);
 	return (ffs_freefile(ump, ump->um_fs, ump->um_devvp, ino, mode, NULL));
 }
 
 /*
  * Do the actual free operation.
  * The specified inode is placed back in the free map.
  */
 int
 ffs_freefile(ump, fs, devvp, ino, mode, wkhd)
 	struct ufsmount *ump;
 	struct fs *fs;
 	struct vnode *devvp;
 	ino_t ino;
 	int mode;
 	struct workhead *wkhd;
 {
 	struct cg *cgp;
 	struct buf *bp;
 	daddr_t dbn;
 	int error;
 	u_int cg;
 	u_int8_t *inosused;
 	struct cdev *dev;
 	ino_t cgino;
 
 	cg = ino_to_cg(fs, ino);
 	if (devvp->v_type == VREG) {
 		/* devvp is a snapshot */
 		MPASS(devvp->v_mount->mnt_data == ump);
 		dev = ump->um_devvp->v_rdev;
 	} else if (devvp->v_type == VCHR) {
 		/* devvp is a normal disk device */
 		dev = devvp->v_rdev;
 	} else {
 		bp = NULL;
 		return (0);
 	}
 	if (ino >= fs->fs_ipg * fs->fs_ncg)
 		panic("ffs_freefile: range: dev = %s, ino = %ju, fs = %s",
 		    devtoname(dev), (uintmax_t)ino, fs->fs_fsmnt);
 	if ((error = ffs_getcg(fs, devvp, cg, GB_CVTENXIO, &bp, &cgp)) != 0) {
 		if (!ffs_fsfail_cleanup(ump, error) ||
 		    !MOUNTEDSOFTDEP(UFSTOVFS(ump)) || devvp->v_type != VCHR)
 			return (error);
 		if (devvp->v_type == VREG)
 			dbn = fragstoblks(fs, cgtod(fs, cg));
 		else
 			dbn = fsbtodb(fs, cgtod(fs, cg));
 		error = getblkx(devvp, dbn, dbn, fs->fs_cgsize, 0, 0, 0, &bp);
 		KASSERT(error == 0, ("getblkx failed"));
 		softdep_setup_inofree(UFSTOVFS(ump), bp, ino, wkhd);
 		bp->b_flags |= B_RELBUF | B_NOCACHE;
 		bp->b_flags &= ~B_CACHE;
 		bawrite(bp);
 		return (error);
 	}
 	inosused = cg_inosused(cgp);
 	cgino = ino % fs->fs_ipg;
 	if (isclr(inosused, cgino)) {
 		printf("dev = %s, ino = %ju, fs = %s\n", devtoname(dev),
 		    (uintmax_t)ino, fs->fs_fsmnt);
 		if (fs->fs_ronly == 0)
 			panic("ffs_freefile: freeing free inode");
 	}
 	clrbit(inosused, cgino);
 	if (cgino < cgp->cg_irotor)
 		cgp->cg_irotor = cgino;
 	cgp->cg_cs.cs_nifree++;
 	UFS_LOCK(ump);
 	fs->fs_cstotal.cs_nifree++;
 	fs->fs_cs(fs, cg).cs_nifree++;
 	if ((mode & IFMT) == IFDIR) {
 		cgp->cg_cs.cs_ndir--;
 		fs->fs_cstotal.cs_ndir--;
 		fs->fs_cs(fs, cg).cs_ndir--;
 	}
 	fs->fs_fmod = 1;
 	ACTIVECLEAR(fs, cg);
 	UFS_UNLOCK(ump);
 	if (MOUNTEDSOFTDEP(UFSTOVFS(ump)) && devvp->v_type == VCHR)
 		softdep_setup_inofree(UFSTOVFS(ump), bp, ino, wkhd);
 	bdwrite(bp);
 	return (0);
 }
 
 /*
  * Check to see if a file is free.
  * Used to check for allocated files in snapshots.
  */
 int
 ffs_checkfreefile(fs, devvp, ino)
 	struct fs *fs;
 	struct vnode *devvp;
 	ino_t ino;
 {
 	struct cg *cgp;
 	struct buf *bp;
 	int ret, error;
 	u_int cg;
 	u_int8_t *inosused;
 
 	cg = ino_to_cg(fs, ino);
 	if ((devvp->v_type != VREG) && (devvp->v_type != VCHR))
 		return (1);
 	if (ino >= fs->fs_ipg * fs->fs_ncg)
 		return (1);
 	if ((error = ffs_getcg(fs, devvp, cg, 0, &bp, &cgp)) != 0)
 		return (1);
 	inosused = cg_inosused(cgp);
 	ino %= fs->fs_ipg;
 	ret = isclr(inosused, ino);
 	brelse(bp);
 	return (ret);
 }
 
 /*
  * Find a block of the specified size in the specified cylinder group.
  *
  * It is a panic if a request is made to find a block if none are
  * available.
  */
 static ufs1_daddr_t
 ffs_mapsearch(fs, cgp, bpref, allocsiz)
 	struct fs *fs;
 	struct cg *cgp;
 	ufs2_daddr_t bpref;
 	int allocsiz;
 {
 	ufs1_daddr_t bno;
 	int start, len, loc, i;
 	int blk, field, subfield, pos;
 	u_int8_t *blksfree;
 
 	/*
 	 * find the fragment by searching through the free block
 	 * map for an appropriate bit pattern
 	 */
 	if (bpref)
 		start = dtogd(fs, bpref) / NBBY;
 	else
 		start = cgp->cg_frotor / NBBY;
 	blksfree = cg_blksfree(cgp);
 	len = howmany(fs->fs_fpg, NBBY) - start;
 	loc = scanc((u_int)len, (u_char *)&blksfree[start],
 		fragtbl[fs->fs_frag],
 		(u_char)(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
 	if (loc == 0) {
 		len = start + 1;
 		start = 0;
 		loc = scanc((u_int)len, (u_char *)&blksfree[0],
 			fragtbl[fs->fs_frag],
 			(u_char)(1 << (allocsiz - 1 + (fs->fs_frag % NBBY))));
 		if (loc == 0) {
 			printf("start = %d, len = %d, fs = %s\n",
 			    start, len, fs->fs_fsmnt);
 			panic("ffs_alloccg: map corrupted");
 			/* NOTREACHED */
 		}
 	}
 	bno = (start + len - loc) * NBBY;
 	cgp->cg_frotor = bno;
 	/*
 	 * found the byte in the map
 	 * sift through the bits to find the selected frag
 	 */
 	for (i = bno + NBBY; bno < i; bno += fs->fs_frag) {
 		blk = blkmap(fs, blksfree, bno);
 		blk <<= 1;
 		field = around[allocsiz];
 		subfield = inside[allocsiz];
 		for (pos = 0; pos <= fs->fs_frag - allocsiz; pos++) {
 			if ((blk & field) == subfield)
 				return (bno + pos);
 			field <<= 1;
 			subfield <<= 1;
 		}
 	}
 	printf("bno = %lu, fs = %s\n", (u_long)bno, fs->fs_fsmnt);
 	panic("ffs_alloccg: block not in map");
 	return (-1);
 }
 
 static const struct statfs *
 ffs_getmntstat(struct vnode *devvp)
 {
 
 	if (devvp->v_type == VCHR)
 		return (&devvp->v_rdev->si_mountpt->mnt_stat);
 	return (ffs_getmntstat(VFSTOUFS(devvp->v_mount)->um_devvp));
 }
 
 /*
  * Fetch and verify a cylinder group.
  */
 int
 ffs_getcg(fs, devvp, cg, flags, bpp, cgpp)
 	struct fs *fs;
 	struct vnode *devvp;
 	u_int cg;
 	int flags;
 	struct buf **bpp;
 	struct cg **cgpp;
 {
 	struct buf *bp;
 	struct cg *cgp;
 	const struct statfs *sfs;
 	daddr_t blkno;
 	int error;
 
 	*bpp = NULL;
 	*cgpp = NULL;
 	if ((fs->fs_metackhash & CK_CYLGRP) != 0)
 		flags |= GB_CKHASH;
 	if (devvp->v_type == VREG)
 		blkno = fragstoblks(fs, cgtod(fs, cg));
 	else
 		blkno = fsbtodb(fs, cgtod(fs, cg));
 	error = breadn_flags(devvp, blkno, blkno, (int)fs->fs_cgsize, NULL,
 	    NULL, 0, NOCRED, flags, ffs_ckhash_cg, &bp);
 	if (error != 0)
 		return (error);
 	cgp = (struct cg *)bp->b_data;
 	if ((fs->fs_metackhash & CK_CYLGRP) != 0 &&
 	    (bp->b_flags & B_CKHASH) != 0 &&
 	    cgp->cg_ckhash != bp->b_ckhash) {
 		sfs = ffs_getmntstat(devvp);
 		printf("UFS %s%s (%s) cylinder checksum failed: cg %u, cgp: "
 		    "0x%x != bp: 0x%jx\n",
 		    devvp->v_type == VCHR ? "" : "snapshot of ",
 		    sfs->f_mntfromname, sfs->f_mntonname,
 		    cg, cgp->cg_ckhash, (uintmax_t)bp->b_ckhash);
 		bp->b_flags &= ~B_CKHASH;
 		bp->b_flags |= B_INVAL | B_NOCACHE;
 		brelse(bp);
 		return (EIO);
 	}
 	if (!cg_chkmagic(cgp) || cgp->cg_cgx != cg) {
 		sfs = ffs_getmntstat(devvp);
 		printf("UFS %s%s (%s)",
 		    devvp->v_type == VCHR ? "" : "snapshot of ",
 		    sfs->f_mntfromname, sfs->f_mntonname);
 		if (!cg_chkmagic(cgp))
 			printf(" cg %u: bad magic number 0x%x should be 0x%x\n",
 			    cg, cgp->cg_magic, CG_MAGIC);
 		else
 			printf(": wrong cylinder group cg %u != cgx %u\n", cg,
 			    cgp->cg_cgx);
 		bp->b_flags &= ~B_CKHASH;
 		bp->b_flags |= B_INVAL | B_NOCACHE;
 		brelse(bp);
 		return (EIO);
 	}
 	bp->b_flags &= ~B_CKHASH;
 	bp->b_xflags |= BX_BKGRDWRITE;
 	/*
 	 * If we are using check hashes on the cylinder group then we want
 	 * to limit changing the cylinder group time to when we are actually
 	 * going to write it to disk so that its check hash remains correct
 	 * in memory. If the CK_CYLGRP flag is set the time is updated in
 	 * ffs_bufwrite() as the buffer is queued for writing. Otherwise we
 	 * update the time here as we have done historically.
 	 */
 	if ((fs->fs_metackhash & CK_CYLGRP) != 0)
 		bp->b_xflags |= BX_CYLGRP;
 	else
 		cgp->cg_old_time = cgp->cg_time = time_second;
 	*bpp = bp;
 	*cgpp = cgp;
 	return (0);
 }
 
 static void
 ffs_ckhash_cg(bp)
 	struct buf *bp;
 {
 	uint32_t ckhash;
 	struct cg *cgp;
 
 	cgp = (struct cg *)bp->b_data;
 	ckhash = cgp->cg_ckhash;
 	cgp->cg_ckhash = 0;
 	bp->b_ckhash = calculate_crc32c(~0L, bp->b_data, bp->b_bcount);
 	cgp->cg_ckhash = ckhash;
 }
 
 /*
  * Fserr prints the name of a filesystem with an error diagnostic.
  *
  * The form of the error message is:
  *	fs: error message
  */
 void
 ffs_fserr(fs, inum, cp)
 	struct fs *fs;
 	ino_t inum;
 	char *cp;
 {
 	struct thread *td = curthread;	/* XXX */
 	struct proc *p = td->td_proc;
 
 	log(LOG_ERR, "pid %d (%s), uid %d inumber %ju on %s: %s\n",
 	    p->p_pid, p->p_comm, td->td_ucred->cr_uid, (uintmax_t)inum,
 	    fs->fs_fsmnt, cp);
 }
 
 /*
  * This function provides the capability for the fsck program to
  * update an active filesystem. Fourteen operations are provided:
  *
  * adjrefcnt(inode, amt) - adjusts the reference count on the
  *	specified inode by the specified amount. Under normal
  *	operation the count should always go down. Decrementing
  *	the count to zero will cause the inode to be freed.
  * adjblkcnt(inode, amt) - adjust the number of blocks used by the
  *	inode by the specified amount.
  * setsize(inode, size) - set the size of the inode to the
  *	specified size.
  * adjndir, adjbfree, adjifree, adjffree, adjnumclusters(amt) -
  *	adjust the superblock summary.
  * freedirs(inode, count) - directory inodes [inode..inode + count - 1]
  *	are marked as free. Inodes should never have to be marked
  *	as in use.
  * freefiles(inode, count) - file inodes [inode..inode + count - 1]
  *	are marked as free. Inodes should never have to be marked
  *	as in use.
  * freeblks(blockno, size) - blocks [blockno..blockno + size - 1]
  *	are marked as free. Blocks should never have to be marked
  *	as in use.
  * setflags(flags, set/clear) - the fs_flags field has the specified
  *	flags set (second parameter +1) or cleared (second parameter -1).
  * setcwd(dirinode) - set the current directory to dirinode in the
  *	filesystem associated with the snapshot.
  * setdotdot(oldvalue, newvalue) - Verify that the inode number for ".."
  *	in the current directory is oldvalue then change it to newvalue.
  * unlink(nameptr, oldvalue) - Verify that the inode number associated
  *	with nameptr in the current directory is oldvalue then unlink it.
  */
 
 static int sysctl_ffs_fsck(SYSCTL_HANDLER_ARGS);
 
 SYSCTL_PROC(_vfs_ffs, FFS_ADJ_REFCNT, adjrefcnt,
     CTLFLAG_WR | CTLTYPE_STRUCT | CTLFLAG_NEEDGIANT,
     0, 0, sysctl_ffs_fsck, "S,fsck",
     "Adjust Inode Reference Count");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_ADJ_BLKCNT, adjblkcnt,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Adjust Inode Used Blocks Count");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_SET_SIZE, setsize,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Set the inode size");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_ADJ_NDIR, adjndir,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Adjust number of directories");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_ADJ_NBFREE, adjnbfree,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Adjust number of free blocks");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_ADJ_NIFREE, adjnifree,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Adjust number of free inodes");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_ADJ_NFFREE, adjnffree,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Adjust number of free frags");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_ADJ_NUMCLUSTERS, adjnumclusters,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Adjust number of free clusters");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_DIR_FREE, freedirs,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Free Range of Directory Inodes");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_FILE_FREE, freefiles,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Free Range of File Inodes");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_BLK_FREE, freeblks,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Free Range of Blocks");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_SET_FLAGS, setflags,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Change Filesystem Flags");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_SET_CWD, setcwd,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Set Current Working Directory");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_SET_DOTDOT, setdotdot,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Change Value of .. Entry");
 
 static SYSCTL_NODE(_vfs_ffs, FFS_UNLINK, unlink,
     CTLFLAG_WR | CTLFLAG_NEEDGIANT, sysctl_ffs_fsck,
     "Unlink a Duplicate Name");
 
 #ifdef DIAGNOSTIC
 static int fsckcmds = 0;
 SYSCTL_INT(_debug, OID_AUTO, ffs_fsckcmds, CTLFLAG_RW, &fsckcmds, 0,
 	"print out fsck_ffs-based filesystem update commands");
 #endif /* DIAGNOSTIC */
 
 static int
 sysctl_ffs_fsck(SYSCTL_HANDLER_ARGS)
 {
 	struct thread *td = curthread;
 	struct fsck_cmd cmd;
 	struct ufsmount *ump;
 	struct vnode *vp, *dvp, *fdvp;
 	struct inode *ip, *dp;
 	struct mount *mp;
 	struct fs *fs;
 	struct pwd *pwd;
 	ufs2_daddr_t blkno;
 	long blkcnt, blksize;
 	u_long key;
 	struct file *fp;
 	cap_rights_t rights;
 	int filetype, error;
 
-	if (req->newlen > sizeof cmd)
+	if (req->newptr == NULL || req->newlen > sizeof(cmd))
 		return (EBADRPC);
-	if ((error = SYSCTL_IN(req, &cmd, sizeof cmd)) != 0)
+	if ((error = SYSCTL_IN(req, &cmd, sizeof(cmd))) != 0)
 		return (error);
 	if (cmd.version != FFS_CMD_VERSION)
 		return (ERPCMISMATCH);
 	if ((error = getvnode(td, cmd.handle,
 	    cap_rights_init_one(&rights, CAP_FSCK), &fp)) != 0)
 		return (error);
 	vp = fp->f_vnode;
 	if (vp->v_type != VREG && vp->v_type != VDIR) {
 		fdrop(fp, td);
 		return (EINVAL);
 	}
 	vn_start_write(vp, &mp, V_WAIT);
 	if (mp == NULL ||
 	    strncmp(mp->mnt_stat.f_fstypename, "ufs", MFSNAMELEN)) {
 		vn_finished_write(mp);
 		fdrop(fp, td);
 		return (EINVAL);
 	}
 	ump = VFSTOUFS(mp);
 	if ((mp->mnt_flag & MNT_RDONLY) &&
 	    ump->um_fsckpid != td->td_proc->p_pid) {
 		vn_finished_write(mp);
 		fdrop(fp, td);
 		return (EROFS);
 	}
 	fs = ump->um_fs;
 	filetype = IFREG;
 
 	switch (oidp->oid_number) {
 	case FFS_SET_FLAGS:
 #ifdef DIAGNOSTIC
 		if (fsckcmds)
 			printf("%s: %s flags\n", mp->mnt_stat.f_mntonname,
 			    cmd.size > 0 ? "set" : "clear");
 #endif /* DIAGNOSTIC */
 		if (cmd.size > 0)
 			fs->fs_flags |= (long)cmd.value;
 		else
 			fs->fs_flags &= ~(long)cmd.value;
 		break;
 
 	case FFS_ADJ_REFCNT:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust inode %jd link count by %jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value,
 			    (intmax_t)cmd.size);
 		}
 #endif /* DIAGNOSTIC */
 		if ((error = ffs_vget(mp, (ino_t)cmd.value, LK_EXCLUSIVE, &vp)))
 			break;
 		ip = VTOI(vp);
 		ip->i_nlink += cmd.size;
 		DIP_SET(ip, i_nlink, ip->i_nlink);
 		ip->i_effnlink += cmd.size;
 		UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_MODIFIED);
 		error = ffs_update(vp, 1);
 		if (DOINGSOFTDEP(vp))
 			softdep_change_linkcnt(ip);
 		vput(vp);
 		break;
 
 	case FFS_ADJ_BLKCNT:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust inode %jd block count by %jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value,
 			    (intmax_t)cmd.size);
 		}
 #endif /* DIAGNOSTIC */
 		if ((error = ffs_vget(mp, (ino_t)cmd.value, LK_EXCLUSIVE, &vp)))
 			break;
 		ip = VTOI(vp);
 		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) + cmd.size);
 		UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_MODIFIED);
 		error = ffs_update(vp, 1);
 		vput(vp);
 		break;
 
 	case FFS_SET_SIZE:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: set inode %jd size to %jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value,
 			    (intmax_t)cmd.size);
 		}
 #endif /* DIAGNOSTIC */
 		if ((error = ffs_vget(mp, (ino_t)cmd.value, LK_EXCLUSIVE, &vp)))
 			break;
 		ip = VTOI(vp);
 		DIP_SET(ip, i_size, cmd.size);
 		UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_MODIFIED);
 		error = ffs_update(vp, 1);
 		vput(vp);
 		break;
 
 	case FFS_DIR_FREE:
 		filetype = IFDIR;
 		/* fall through */
 
 	case FFS_FILE_FREE:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			if (cmd.size == 1)
 				printf("%s: free %s inode %ju\n",
 				    mp->mnt_stat.f_mntonname,
 				    filetype == IFDIR ? "directory" : "file",
 				    (uintmax_t)cmd.value);
 			else
 				printf("%s: free %s inodes %ju-%ju\n",
 				    mp->mnt_stat.f_mntonname,
 				    filetype == IFDIR ? "directory" : "file",
 				    (uintmax_t)cmd.value,
 				    (uintmax_t)(cmd.value + cmd.size - 1));
 		}
 #endif /* DIAGNOSTIC */
 		while (cmd.size > 0) {
 			if ((error = ffs_freefile(ump, fs, ump->um_devvp,
 			    cmd.value, filetype, NULL)))
 				break;
 			cmd.size -= 1;
 			cmd.value += 1;
 		}
 		break;
 
 	case FFS_BLK_FREE:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			if (cmd.size == 1)
 				printf("%s: free block %jd\n",
 				    mp->mnt_stat.f_mntonname,
 				    (intmax_t)cmd.value);
 			else
 				printf("%s: free blocks %jd-%jd\n",
 				    mp->mnt_stat.f_mntonname, 
 				    (intmax_t)cmd.value,
 				    (intmax_t)cmd.value + cmd.size - 1);
 		}
 #endif /* DIAGNOSTIC */
 		blkno = cmd.value;
 		blkcnt = cmd.size;
 		blksize = fs->fs_frag - (blkno % fs->fs_frag);
 		key = ffs_blkrelease_start(ump, ump->um_devvp, UFS_ROOTINO);
 		while (blkcnt > 0) {
 			if (blkcnt < blksize)
 				blksize = blkcnt;
 			ffs_blkfree(ump, fs, ump->um_devvp, blkno,
 			    blksize * fs->fs_fsize, UFS_ROOTINO, 
 			    VDIR, NULL, key);
 			blkno += blksize;
 			blkcnt -= blksize;
 			blksize = fs->fs_frag;
 		}
 		ffs_blkrelease_finish(ump, key);
 		break;
 
 	/*
 	 * Adjust superblock summaries.  fsck(8) is expected to
 	 * submit deltas when necessary.
 	 */
 	case FFS_ADJ_NDIR:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust number of directories by %jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value);
 		}
 #endif /* DIAGNOSTIC */
 		fs->fs_cstotal.cs_ndir += cmd.value;
 		break;
 
 	case FFS_ADJ_NBFREE:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust number of free blocks by %+jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value);
 		}
 #endif /* DIAGNOSTIC */
 		fs->fs_cstotal.cs_nbfree += cmd.value;
 		break;
 
 	case FFS_ADJ_NIFREE:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust number of free inodes by %+jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value);
 		}
 #endif /* DIAGNOSTIC */
 		fs->fs_cstotal.cs_nifree += cmd.value;
 		break;
 
 	case FFS_ADJ_NFFREE:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust number of free frags by %+jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value);
 		}
 #endif /* DIAGNOSTIC */
 		fs->fs_cstotal.cs_nffree += cmd.value;
 		break;
 
 	case FFS_ADJ_NUMCLUSTERS:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: adjust number of free clusters by %+jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value);
 		}
 #endif /* DIAGNOSTIC */
 		fs->fs_cstotal.cs_numclusters += cmd.value;
 		break;
 
 	case FFS_SET_CWD:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: set current directory to inode %jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value);
 		}
 #endif /* DIAGNOSTIC */
 		if ((error = ffs_vget(mp, (ino_t)cmd.value, LK_SHARED, &vp)))
 			break;
 		AUDIT_ARG_VNODE1(vp);
 		if ((error = change_dir(vp, td)) != 0) {
 			vput(vp);
 			break;
 		}
 		VOP_UNLOCK(vp);
 		pwd_chdir(td, vp);
 		break;
 
 	case FFS_SET_DOTDOT:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("%s: change .. in cwd from %jd to %jd\n",
 			    mp->mnt_stat.f_mntonname, (intmax_t)cmd.value,
 			    (intmax_t)cmd.size);
 		}
 #endif /* DIAGNOSTIC */
 		/*
 		 * First we have to get and lock the parent directory
 		 * to which ".." points.
 		 */
 		error = ffs_vget(mp, (ino_t)cmd.value, LK_EXCLUSIVE, &fdvp);
 		if (error)
 			break;
 		/*
 		 * Now we get and lock the child directory containing "..".
 		 */
 		pwd = pwd_hold(td);
 		dvp = pwd->pwd_cdir;
 		if ((error = vget(dvp, LK_EXCLUSIVE)) != 0) {
 			vput(fdvp);
 			pwd_drop(pwd);
 			break;
 		}
 		dp = VTOI(dvp);
 		SET_I_OFFSET(dp, 12);	/* XXX mastertemplate.dot_reclen */
 		error = ufs_dirrewrite(dp, VTOI(fdvp), (ino_t)cmd.size,
 		    DT_DIR, 0);
 		cache_purge(fdvp);
 		cache_purge(dvp);
 		vput(dvp);
 		vput(fdvp);
 		pwd_drop(pwd);
 		break;
 
 	case FFS_UNLINK:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			char buf[32];
 
 			if (copyinstr((char *)(intptr_t)cmd.value, buf,32,NULL))
 				strncpy(buf, "Name_too_long", 32);
 			printf("%s: unlink %s (inode %jd)\n",
 			    mp->mnt_stat.f_mntonname, buf, (intmax_t)cmd.size);
 		}
 #endif /* DIAGNOSTIC */
 		/*
 		 * kern_funlinkat will do its own start/finish writes and
 		 * they do not nest, so drop ours here. Setting mp == NULL
 		 * indicates that vn_finished_write is not needed down below.
 		 */
 		vn_finished_write(mp);
 		mp = NULL;
 		error = kern_funlinkat(td, AT_FDCWD,
 		    (char *)(intptr_t)cmd.value, FD_NONE, UIO_USERSPACE,
 		    0, (ino_t)cmd.size);
 		break;
 
 	default:
 #ifdef DIAGNOSTIC
 		if (fsckcmds) {
 			printf("Invalid request %d from fsck\n",
 			    oidp->oid_number);
 		}
 #endif /* DIAGNOSTIC */
 		error = EINVAL;
 		break;
 	}
 	fdrop(fp, td);
 	vn_finished_write(mp);
 	return (error);
 }