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ffs_inode.c revision 1.100
      1 /*	$NetBSD: ffs_inode.c,v 1.100 2008/12/17 20:51:38 cegger Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Wasabi Systems, Inc.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * Copyright (c) 1982, 1986, 1989, 1993
     34  *	The Regents of the University of California.  All rights reserved.
     35  *
     36  * Redistribution and use in source and binary forms, with or without
     37  * modification, are permitted provided that the following conditions
     38  * are met:
     39  * 1. Redistributions of source code must retain the above copyright
     40  *    notice, this list of conditions and the following disclaimer.
     41  * 2. Redistributions in binary form must reproduce the above copyright
     42  *    notice, this list of conditions and the following disclaimer in the
     43  *    documentation and/or other materials provided with the distribution.
     44  * 3. Neither the name of the University nor the names of its contributors
     45  *    may be used to endorse or promote products derived from this software
     46  *    without specific prior written permission.
     47  *
     48  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     49  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     50  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     51  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     52  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     53  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     54  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     55  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     56  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     57  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     58  * SUCH DAMAGE.
     59  *
     60  *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
     61  */
     62 
     63 #include <sys/cdefs.h>
     64 __KERNEL_RCSID(0, "$NetBSD: ffs_inode.c,v 1.100 2008/12/17 20:51:38 cegger Exp $");
     65 
     66 #if defined(_KERNEL_OPT)
     67 #include "opt_ffs.h"
     68 #include "opt_quota.h"
     69 #endif
     70 
     71 #include <sys/param.h>
     72 #include <sys/systm.h>
     73 #include <sys/buf.h>
     74 #include <sys/file.h>
     75 #include <sys/fstrans.h>
     76 #include <sys/kauth.h>
     77 #include <sys/kernel.h>
     78 #include <sys/malloc.h>
     79 #include <sys/mount.h>
     80 #include <sys/proc.h>
     81 #include <sys/resourcevar.h>
     82 #include <sys/trace.h>
     83 #include <sys/vnode.h>
     84 #include <sys/wapbl.h>
     85 
     86 #include <ufs/ufs/quota.h>
     87 #include <ufs/ufs/inode.h>
     88 #include <ufs/ufs/ufsmount.h>
     89 #include <ufs/ufs/ufs_extern.h>
     90 #include <ufs/ufs/ufs_bswap.h>
     91 #include <ufs/ufs/ufs_wapbl.h>
     92 
     93 #include <ufs/ffs/fs.h>
     94 #include <ufs/ffs/ffs_extern.h>
     95 
     96 static int ffs_indirtrunc(struct inode *, daddr_t, daddr_t, daddr_t, int,
     97 			  int64_t *);
     98 
     99 /*
    100  * Update the access, modified, and inode change times as specified
    101  * by the IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.
    102  * The IN_MODIFIED flag is used to specify that the inode needs to be
    103  * updated but that the times have already been set. The access
    104  * and modified times are taken from the second and third parameters;
    105  * the inode change time is always taken from the current time. If
    106  * UPDATE_WAIT flag is set, or UPDATE_DIROP is set and we are not doing
    107  * softupdates, then wait for the disk write of the inode to complete.
    108  */
    109 
    110 int
    111 ffs_update(struct vnode *vp, const struct timespec *acc,
    112     const struct timespec *mod, int updflags)
    113 {
    114 	struct fs *fs;
    115 	struct buf *bp;
    116 	struct inode *ip;
    117 	int error;
    118 	void *cp;
    119 	int waitfor, flags;
    120 
    121 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    122 		return (0);
    123 	ip = VTOI(vp);
    124 	FFS_ITIMES(ip, acc, mod, NULL);
    125 	if (updflags & UPDATE_CLOSE)
    126 		flags = ip->i_flag & (IN_MODIFIED | IN_ACCESSED);
    127 	else
    128 		flags = ip->i_flag & IN_MODIFIED;
    129 	if (flags == 0)
    130 		return (0);
    131 	fs = ip->i_fs;
    132 
    133 	if ((flags & IN_MODIFIED) != 0 &&
    134 	    (vp->v_mount->mnt_flag & MNT_ASYNC) == 0) {
    135 		waitfor = updflags & UPDATE_WAIT;
    136 		if ((updflags & UPDATE_DIROP) && !DOINGSOFTDEP(vp))
    137 			waitfor |= UPDATE_WAIT;
    138 	} else
    139 		waitfor = 0;
    140 
    141 	/*
    142 	 * Ensure that uid and gid are correct. This is a temporary
    143 	 * fix until fsck has been changed to do the update.
    144 	 */
    145 	if (fs->fs_magic == FS_UFS1_MAGIC &&			/* XXX */
    146 	    fs->fs_old_inodefmt < FS_44INODEFMT) {		/* XXX */
    147 		ip->i_ffs1_ouid = ip->i_uid;	/* XXX */
    148 		ip->i_ffs1_ogid = ip->i_gid;	/* XXX */
    149 	}							/* XXX */
    150 	error = bread(ip->i_devvp,
    151 		      fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
    152 		      (int)fs->fs_bsize, NOCRED, B_MODIFY, &bp);
    153 	if (error) {
    154 		brelse(bp, 0);
    155 		return (error);
    156 	}
    157 	ip->i_flag &= ~(IN_MODIFIED | IN_ACCESSED);
    158 	if (DOINGSOFTDEP(vp)) {
    159 		softdep_update_inodeblock(ip, bp, waitfor);
    160 	} else if (ip->i_ffs_effnlink != ip->i_nlink)
    161 		panic("ffs_update: bad link cnt");
    162 	/* Keep unlinked inode list up to date */
    163 	KDASSERT(DIP(ip, nlink) == ip->i_nlink);
    164 	if (ip->i_mode) {
    165 		if (ip->i_nlink > 0) {
    166 			UFS_WAPBL_UNREGISTER_INODE(ip->i_ump->um_mountp,
    167 			    ip->i_number, ip->i_mode);
    168 		} else {
    169 			UFS_WAPBL_REGISTER_INODE(ip->i_ump->um_mountp,
    170 			    ip->i_number, ip->i_mode);
    171 		}
    172 	}
    173 	if (fs->fs_magic == FS_UFS1_MAGIC) {
    174 		cp = (char *)bp->b_data +
    175 		    (ino_to_fsbo(fs, ip->i_number) * DINODE1_SIZE);
    176 #ifdef FFS_EI
    177 		if (UFS_FSNEEDSWAP(fs))
    178 			ffs_dinode1_swap(ip->i_din.ffs1_din,
    179 			    (struct ufs1_dinode *)cp);
    180 		else
    181 #endif
    182 			memcpy(cp, ip->i_din.ffs1_din, DINODE1_SIZE);
    183 	} else {
    184 		cp = (char *)bp->b_data +
    185 		    (ino_to_fsbo(fs, ip->i_number) * DINODE2_SIZE);
    186 #ifdef FFS_EI
    187 		if (UFS_FSNEEDSWAP(fs))
    188 			ffs_dinode2_swap(ip->i_din.ffs2_din,
    189 			    (struct ufs2_dinode *)cp);
    190 		else
    191 #endif
    192 			memcpy(cp, ip->i_din.ffs2_din, DINODE2_SIZE);
    193 	}
    194 	if (waitfor) {
    195 		return (bwrite(bp));
    196 	} else {
    197 		bdwrite(bp);
    198 		return (0);
    199 	}
    200 }
    201 
    202 #define	SINGLE	0	/* index of single indirect block */
    203 #define	DOUBLE	1	/* index of double indirect block */
    204 #define	TRIPLE	2	/* index of triple indirect block */
    205 /*
    206  * Truncate the inode oip to at most length size, freeing the
    207  * disk blocks.
    208  */
    209 int
    210 ffs_truncate(struct vnode *ovp, off_t length, int ioflag, kauth_cred_t cred)
    211 {
    212 	daddr_t lastblock;
    213 	struct inode *oip = VTOI(ovp);
    214 	daddr_t bn, lastiblock[NIADDR], indir_lbn[NIADDR];
    215 	daddr_t blks[NDADDR + NIADDR];
    216 	struct fs *fs;
    217 	int offset, pgoffset, level;
    218 	int64_t count, blocksreleased = 0;
    219 	int i, aflag, nblocks;
    220 	int error, allerror = 0;
    221 	off_t osize;
    222 	int sync;
    223 	struct ufsmount *ump = oip->i_ump;
    224 
    225 	if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
    226 	    ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
    227 		KASSERT(oip->i_size == 0);
    228 		return 0;
    229 	}
    230 
    231 	if (length < 0)
    232 		return (EINVAL);
    233 
    234 	if (ovp->v_type == VLNK &&
    235 	    (oip->i_size < ump->um_maxsymlinklen ||
    236 	     (ump->um_maxsymlinklen == 0 && DIP(oip, blocks) == 0))) {
    237 		KDASSERT(length == 0);
    238 		memset(SHORTLINK(oip), 0, (size_t)oip->i_size);
    239 		oip->i_size = 0;
    240 		DIP_ASSIGN(oip, size, 0);
    241 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    242 		return (ffs_update(ovp, NULL, NULL, 0));
    243 	}
    244 	if (oip->i_size == length) {
    245 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    246 		return (ffs_update(ovp, NULL, NULL, 0));
    247 	}
    248 	fs = oip->i_fs;
    249 	if (length > ump->um_maxfilesize)
    250 		return (EFBIG);
    251 
    252 	if ((oip->i_flags & SF_SNAPSHOT) != 0)
    253 		ffs_snapremove(ovp);
    254 
    255 	osize = oip->i_size;
    256 	aflag = ioflag & IO_SYNC ? B_SYNC : 0;
    257 
    258 	/*
    259 	 * Lengthen the size of the file. We must ensure that the
    260 	 * last byte of the file is allocated. Since the smallest
    261 	 * value of osize is 0, length will be at least 1.
    262 	 */
    263 
    264 	if (osize < length) {
    265 		if (lblkno(fs, osize) < NDADDR &&
    266 		    lblkno(fs, osize) != lblkno(fs, length) &&
    267 		    blkroundup(fs, osize) != osize) {
    268 			off_t eob;
    269 
    270 			eob = blkroundup(fs, osize);
    271 			uvm_vnp_setwritesize(ovp, eob);
    272 			error = ufs_balloc_range(ovp, osize, eob - osize,
    273 			    cred, aflag);
    274 			if (error)
    275 				return error;
    276 			if (ioflag & IO_SYNC) {
    277 				mutex_enter(&ovp->v_interlock);
    278 				VOP_PUTPAGES(ovp,
    279 				    trunc_page(osize & fs->fs_bmask),
    280 				    round_page(eob), PGO_CLEANIT | PGO_SYNCIO |
    281 				    PGO_JOURNALLOCKED);
    282 			}
    283 		}
    284 		uvm_vnp_setwritesize(ovp, length);
    285 		error = ufs_balloc_range(ovp, length - 1, 1, cred, aflag);
    286 		if (error) {
    287 			(void) ffs_truncate(ovp, osize, ioflag & IO_SYNC, cred);
    288 			return (error);
    289 		}
    290 		uvm_vnp_setsize(ovp, length);
    291 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    292 		KASSERT(ovp->v_size == oip->i_size);
    293 		return (ffs_update(ovp, NULL, NULL, 0));
    294 	}
    295 
    296 	/*
    297 	 * When truncating a regular file down to a non-block-aligned size,
    298 	 * we must zero the part of last block which is past the new EOF.
    299 	 * We must synchronously flush the zeroed pages to disk
    300 	 * since the new pages will be invalidated as soon as we
    301 	 * inform the VM system of the new, smaller size.
    302 	 * We must do this before acquiring the GLOCK, since fetching
    303 	 * the pages will acquire the GLOCK internally.
    304 	 * So there is a window where another thread could see a whole
    305 	 * zeroed page past EOF, but that's life.
    306 	 */
    307 
    308 	offset = blkoff(fs, length);
    309 	pgoffset = length & PAGE_MASK;
    310 	if (ovp->v_type == VREG && (pgoffset != 0 || offset != 0) &&
    311 	    osize > length) {
    312 		daddr_t lbn;
    313 		voff_t eoz;
    314 		int size;
    315 
    316 		if (offset != 0) {
    317 			error = ufs_balloc_range(ovp, length - 1, 1, cred,
    318 			    aflag);
    319 			if (error)
    320 				return error;
    321 		}
    322 		lbn = lblkno(fs, length);
    323 		size = blksize(fs, oip, lbn);
    324 		eoz = MIN(MAX(lblktosize(fs, lbn) + size, round_page(pgoffset)),
    325 		    osize);
    326 		uvm_vnp_zerorange(ovp, length, eoz - length);
    327 		if (round_page(eoz) > round_page(length)) {
    328 			mutex_enter(&ovp->v_interlock);
    329 			error = VOP_PUTPAGES(ovp, round_page(length),
    330 			    round_page(eoz),
    331 			    PGO_CLEANIT | PGO_DEACTIVATE | PGO_JOURNALLOCKED |
    332 			    ((ioflag & IO_SYNC) ? PGO_SYNCIO : 0));
    333 			if (error)
    334 				return error;
    335 		}
    336 	}
    337 
    338 	genfs_node_wrlock(ovp);
    339 
    340 	if (DOINGSOFTDEP(ovp)) {
    341 		if (length > 0) {
    342 			/*
    343 			 * If a file is only partially truncated, then
    344 			 * we have to clean up the data structures
    345 			 * describing the allocation past the truncation
    346 			 * point. Finding and deallocating those structures
    347 			 * is a lot of work. Since partial truncation occurs
    348 			 * rarely, we solve the problem by syncing the file
    349 			 * so that it will have no data structures left.
    350 			 */
    351 			if ((error = VOP_FSYNC(ovp, cred, FSYNC_WAIT,
    352 			    0, 0)) != 0) {
    353 				genfs_node_unlock(ovp);
    354 				return (error);
    355 			}
    356 			mutex_enter(&ump->um_lock);
    357 			if (oip->i_flag & IN_SPACECOUNTED)
    358 				fs->fs_pendingblocks -= DIP(oip, blocks);
    359 			mutex_exit(&ump->um_lock);
    360 		} else {
    361 			uvm_vnp_setsize(ovp, length);
    362 #ifdef QUOTA
    363  			(void) chkdq(oip, -DIP(oip, blocks), NOCRED, 0);
    364 #endif
    365 			softdep_setup_freeblocks(oip, length, 0);
    366 			(void) vinvalbuf(ovp, 0, cred, curlwp, 0, 0);
    367 			genfs_node_unlock(ovp);
    368 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    369 			return (ffs_update(ovp, NULL, NULL, 0));
    370 		}
    371 	}
    372 	oip->i_size = length;
    373 	DIP_ASSIGN(oip, size, length);
    374 	uvm_vnp_setsize(ovp, length);
    375 	/*
    376 	 * Calculate index into inode's block list of
    377 	 * last direct and indirect blocks (if any)
    378 	 * which we want to keep.  Lastblock is -1 when
    379 	 * the file is truncated to 0.
    380 	 */
    381 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
    382 	lastiblock[SINGLE] = lastblock - NDADDR;
    383 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    384 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    385 	nblocks = btodb(fs->fs_bsize);
    386 	/*
    387 	 * Update file and block pointers on disk before we start freeing
    388 	 * blocks.  If we crash before free'ing blocks below, the blocks
    389 	 * will be returned to the free list.  lastiblock values are also
    390 	 * normalized to -1 for calls to ffs_indirtrunc below.
    391 	 */
    392 	sync = 0;
    393 	for (level = TRIPLE; level >= SINGLE; level--) {
    394 		blks[NDADDR + level] = DIP(oip, ib[level]);
    395 		if (lastiblock[level] < 0 && blks[NDADDR + level] != 0) {
    396 			sync = 1;
    397 			DIP_ASSIGN(oip, ib[level], 0);
    398 			lastiblock[level] = -1;
    399 		}
    400 	}
    401 	for (i = 0; i < NDADDR; i++) {
    402 		blks[i] = DIP(oip, db[i]);
    403 		if (i > lastblock && blks[i] != 0) {
    404 			sync = 1;
    405 			DIP_ASSIGN(oip, db[i], 0);
    406 		}
    407 	}
    408 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
    409 	if (sync) {
    410 		error = ffs_update(ovp, NULL, NULL, UPDATE_WAIT);
    411 		if (error && !allerror)
    412 			allerror = error;
    413 	}
    414 
    415 	/*
    416 	 * Having written the new inode to disk, save its new configuration
    417 	 * and put back the old block pointers long enough to process them.
    418 	 * Note that we save the new block configuration so we can check it
    419 	 * when we are done.
    420 	 */
    421 	for (i = 0; i < NDADDR; i++) {
    422 		bn = DIP(oip, db[i]);
    423 		DIP_ASSIGN(oip, db[i], blks[i]);
    424 		blks[i] = bn;
    425 	}
    426 	for (i = 0; i < NIADDR; i++) {
    427 		bn = DIP(oip, ib[i]);
    428 		DIP_ASSIGN(oip, ib[i], blks[NDADDR + i]);
    429 		blks[NDADDR + i] = bn;
    430 	}
    431 
    432 	oip->i_size = osize;
    433 	DIP_ASSIGN(oip, size, osize);
    434 	error = vtruncbuf(ovp, lastblock + 1, 0, 0);
    435 	if (error && !allerror)
    436 		allerror = error;
    437 
    438 	/*
    439 	 * Indirect blocks first.
    440 	 */
    441 	indir_lbn[SINGLE] = -NDADDR;
    442 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    443 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    444 	for (level = TRIPLE; level >= SINGLE; level--) {
    445 		if (oip->i_ump->um_fstype == UFS1)
    446 			bn = ufs_rw32(oip->i_ffs1_ib[level],UFS_FSNEEDSWAP(fs));
    447 		else
    448 			bn = ufs_rw64(oip->i_ffs2_ib[level],UFS_FSNEEDSWAP(fs));
    449 		if (bn != 0) {
    450 			error = ffs_indirtrunc(oip, indir_lbn[level],
    451 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
    452 			if (error)
    453 				allerror = error;
    454 			blocksreleased += count;
    455 			if (lastiblock[level] < 0) {
    456 				DIP_ASSIGN(oip, ib[level], 0);
    457 				if (oip->i_ump->um_mountp->mnt_wapbl) {
    458 					UFS_WAPBL_REGISTER_DEALLOCATION(
    459 					    oip->i_ump->um_mountp,
    460 					    fsbtodb(fs, bn), fs->fs_bsize);
    461 				} else
    462 					ffs_blkfree(fs, oip->i_devvp, bn,
    463 					    fs->fs_bsize, oip->i_number);
    464 				blocksreleased += nblocks;
    465 			}
    466 		}
    467 		if (lastiblock[level] >= 0)
    468 			goto done;
    469 	}
    470 
    471 	/*
    472 	 * All whole direct blocks or frags.
    473 	 */
    474 	for (i = NDADDR - 1; i > lastblock; i--) {
    475 		long bsize;
    476 
    477 		if (oip->i_ump->um_fstype == UFS1)
    478 			bn = ufs_rw32(oip->i_ffs1_db[i], UFS_FSNEEDSWAP(fs));
    479 		else
    480 			bn = ufs_rw64(oip->i_ffs2_db[i], UFS_FSNEEDSWAP(fs));
    481 		if (bn == 0)
    482 			continue;
    483 		DIP_ASSIGN(oip, db[i], 0);
    484 		bsize = blksize(fs, oip, i);
    485 		if ((oip->i_ump->um_mountp->mnt_wapbl) &&
    486 		    (ovp->v_type != VREG)) {
    487 			UFS_WAPBL_REGISTER_DEALLOCATION(oip->i_ump->um_mountp,
    488 			    fsbtodb(fs, bn), bsize);
    489 		} else
    490 			ffs_blkfree(fs, oip->i_devvp, bn, bsize, oip->i_number);
    491 		blocksreleased += btodb(bsize);
    492 	}
    493 	if (lastblock < 0)
    494 		goto done;
    495 
    496 	/*
    497 	 * Finally, look for a change in size of the
    498 	 * last direct block; release any frags.
    499 	 */
    500 	if (oip->i_ump->um_fstype == UFS1)
    501 		bn = ufs_rw32(oip->i_ffs1_db[lastblock], UFS_FSNEEDSWAP(fs));
    502 	else
    503 		bn = ufs_rw64(oip->i_ffs2_db[lastblock], UFS_FSNEEDSWAP(fs));
    504 	if (bn != 0) {
    505 		long oldspace, newspace;
    506 
    507 		/*
    508 		 * Calculate amount of space we're giving
    509 		 * back as old block size minus new block size.
    510 		 */
    511 		oldspace = blksize(fs, oip, lastblock);
    512 		oip->i_size = length;
    513 		DIP_ASSIGN(oip, size, length);
    514 		newspace = blksize(fs, oip, lastblock);
    515 		if (newspace == 0)
    516 			panic("itrunc: newspace");
    517 		if (oldspace - newspace > 0) {
    518 			/*
    519 			 * Block number of space to be free'd is
    520 			 * the old block # plus the number of frags
    521 			 * required for the storage we're keeping.
    522 			 */
    523 			bn += numfrags(fs, newspace);
    524 			if ((oip->i_ump->um_mountp->mnt_wapbl) &&
    525 			    (ovp->v_type != VREG)) {
    526 				UFS_WAPBL_REGISTER_DEALLOCATION(
    527 				    oip->i_ump->um_mountp, fsbtodb(fs, bn),
    528 				    oldspace - newspace);
    529 			} else
    530 				ffs_blkfree(fs, oip->i_devvp, bn,
    531 				    oldspace - newspace, oip->i_number);
    532 			blocksreleased += btodb(oldspace - newspace);
    533 		}
    534 	}
    535 
    536 done:
    537 #ifdef DIAGNOSTIC
    538 	for (level = SINGLE; level <= TRIPLE; level++)
    539 		if (blks[NDADDR + level] != DIP(oip, ib[level]))
    540 			panic("itrunc1");
    541 	for (i = 0; i < NDADDR; i++)
    542 		if (blks[i] != DIP(oip, db[i]))
    543 			panic("itrunc2");
    544 	if (length == 0 &&
    545 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    546 		panic("itrunc3");
    547 #endif /* DIAGNOSTIC */
    548 	/*
    549 	 * Put back the real size.
    550 	 */
    551 	oip->i_size = length;
    552 	DIP_ASSIGN(oip, size, length);
    553 	DIP_ADD(oip, blocks, -blocksreleased);
    554 	genfs_node_unlock(ovp);
    555 	oip->i_flag |= IN_CHANGE;
    556 	UFS_WAPBL_UPDATE(ovp, NULL, NULL, 0);
    557 #ifdef QUOTA
    558 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    559 #endif
    560 	KASSERT(ovp->v_type != VREG || ovp->v_size == oip->i_size);
    561 	return (allerror);
    562 }
    563 
    564 /*
    565  * Release blocks associated with the inode ip and stored in the indirect
    566  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    567  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    568  * and recursive calls to indirtrunc must be used to cleanse other indirect
    569  * blocks.
    570  *
    571  * NB: triple indirect blocks are untested.
    572  */
    573 static int
    574 ffs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn, daddr_t lastbn,
    575     int level, int64_t *countp)
    576 {
    577 	int i;
    578 	struct buf *bp;
    579 	struct fs *fs = ip->i_fs;
    580 	int32_t *bap1 = NULL;
    581 	int64_t *bap2 = NULL;
    582 	struct vnode *vp;
    583 	daddr_t nb, nlbn, last;
    584 	char *copy = NULL;
    585 	int64_t blkcount, factor, blocksreleased = 0;
    586 	int nblocks;
    587 	int error = 0, allerror = 0;
    588 #ifdef FFS_EI
    589 	const int needswap = UFS_FSNEEDSWAP(fs);
    590 #endif
    591 #define RBAP(ip, i) (((ip)->i_ump->um_fstype == UFS1) ? \
    592 	    ufs_rw32(bap1[i], needswap) : ufs_rw64(bap2[i], needswap))
    593 #define BAP_ASSIGN(ip, i, value)					\
    594 	do {								\
    595 		if ((ip)->i_ump->um_fstype == UFS1)			\
    596 			bap1[i] = (value);				\
    597 		else							\
    598 			bap2[i] = (value);				\
    599 	} while(0)
    600 
    601 	/*
    602 	 * Calculate index in current block of last
    603 	 * block to be kept.  -1 indicates the entire
    604 	 * block so we need not calculate the index.
    605 	 */
    606 	factor = 1;
    607 	for (i = SINGLE; i < level; i++)
    608 		factor *= NINDIR(fs);
    609 	last = lastbn;
    610 	if (lastbn > 0)
    611 		last /= factor;
    612 	nblocks = btodb(fs->fs_bsize);
    613 	/*
    614 	 * Get buffer of block pointers, zero those entries corresponding
    615 	 * to blocks to be free'd, and update on disk copy first.  Since
    616 	 * double(triple) indirect before single(double) indirect, calls
    617 	 * to bmap on these blocks will fail.  However, we already have
    618 	 * the on disk address, so we have to set the b_blkno field
    619 	 * explicitly instead of letting bread do everything for us.
    620 	 */
    621 	vp = ITOV(ip);
    622 	error = ffs_getblk(vp, lbn, FFS_NOBLK, fs->fs_bsize, false, &bp);
    623 	if (error) {
    624 		*countp = 0;
    625 		return error;
    626 	}
    627 	if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
    628 		/* Braces must be here in case trace evaluates to nothing. */
    629 		trace(TR_BREADHIT, pack(vp, fs->fs_bsize), lbn);
    630 	} else {
    631 		trace(TR_BREADMISS, pack(vp, fs->fs_bsize), lbn);
    632 		curlwp->l_ru.ru_inblock++;	/* pay for read */
    633 		bp->b_flags |= B_READ;
    634 		bp->b_flags &= ~B_COWDONE;	/* we change blkno below */
    635 		if (bp->b_bcount > bp->b_bufsize)
    636 			panic("ffs_indirtrunc: bad buffer size");
    637 		bp->b_blkno = dbn;
    638 		BIO_SETPRIO(bp, BPRIO_TIMECRITICAL);
    639 		VOP_STRATEGY(vp, bp);
    640 		error = biowait(bp);
    641 		if (error == 0)
    642 			error = fscow_run(bp, true);
    643 	}
    644 	if (error) {
    645 		brelse(bp, 0);
    646 		*countp = 0;
    647 		return (error);
    648 	}
    649 
    650 	if (ip->i_ump->um_fstype == UFS1)
    651 		bap1 = (int32_t *)bp->b_data;
    652 	else
    653 		bap2 = (int64_t *)bp->b_data;
    654 	if (lastbn >= 0) {
    655 		copy = malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
    656 		memcpy((void *)copy, bp->b_data, (u_int)fs->fs_bsize);
    657 		for (i = last + 1; i < NINDIR(fs); i++)
    658 			BAP_ASSIGN(ip, i, 0);
    659 		error = bwrite(bp);
    660 		if (error)
    661 			allerror = error;
    662 		if (ip->i_ump->um_fstype == UFS1)
    663 			bap1 = (int32_t *)copy;
    664 		else
    665 			bap2 = (int64_t *)copy;
    666 	}
    667 
    668 	/*
    669 	 * Recursively free totally unused blocks.
    670 	 */
    671 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    672 	    i--, nlbn += factor) {
    673 		nb = RBAP(ip, i);
    674 		if (nb == 0)
    675 			continue;
    676 		if (level > SINGLE) {
    677 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
    678 					       (daddr_t)-1, level - 1,
    679 					       &blkcount);
    680 			if (error)
    681 				allerror = error;
    682 			blocksreleased += blkcount;
    683 		}
    684 		if ((ip->i_ump->um_mountp->mnt_wapbl) &&
    685 		    ((level > SINGLE) || (ITOV(ip)->v_type != VREG))) {
    686 			UFS_WAPBL_REGISTER_DEALLOCATION(ip->i_ump->um_mountp,
    687 			    fsbtodb(fs, nb), fs->fs_bsize);
    688 		} else
    689 			ffs_blkfree(fs, ip->i_devvp, nb, fs->fs_bsize,
    690 			    ip->i_number);
    691 		blocksreleased += nblocks;
    692 	}
    693 
    694 	/*
    695 	 * Recursively free last partial block.
    696 	 */
    697 	if (level > SINGLE && lastbn >= 0) {
    698 		last = lastbn % factor;
    699 		nb = RBAP(ip, i);
    700 		if (nb != 0) {
    701 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
    702 					       last, level - 1, &blkcount);
    703 			if (error)
    704 				allerror = error;
    705 			blocksreleased += blkcount;
    706 		}
    707 	}
    708 
    709 	if (copy != NULL) {
    710 		free(copy, M_TEMP);
    711 	} else {
    712 		brelse(bp, BC_INVAL);
    713 	}
    714 
    715 	*countp = blocksreleased;
    716 	return (allerror);
    717 }
    718 
    719 void
    720 ffs_itimes(struct inode *ip, const struct timespec *acc,
    721     const struct timespec *mod, const struct timespec *cre)
    722 {
    723 	struct timespec now;
    724 
    725 	if (!(ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE | IN_MODIFY))) {
    726 		return;
    727 	}
    728 
    729 	vfs_timestamp(&now);
    730 	if (ip->i_flag & IN_ACCESS) {
    731 		if (acc == NULL)
    732 			acc = &now;
    733 		DIP_ASSIGN(ip, atime, acc->tv_sec);
    734 		DIP_ASSIGN(ip, atimensec, acc->tv_nsec);
    735 	}
    736 	if (ip->i_flag & (IN_UPDATE | IN_MODIFY)) {
    737 		if ((ip->i_flags & SF_SNAPSHOT) == 0) {
    738 			if (mod == NULL)
    739 				mod = &now;
    740 			DIP_ASSIGN(ip, mtime, mod->tv_sec);
    741 			DIP_ASSIGN(ip, mtimensec, mod->tv_nsec);
    742 		}
    743 		ip->i_modrev++;
    744 	}
    745 	if (ip->i_flag & (IN_CHANGE | IN_MODIFY)) {
    746 		if (cre == NULL)
    747 			cre = &now;
    748 		DIP_ASSIGN(ip, ctime, cre->tv_sec);
    749 		DIP_ASSIGN(ip, ctimensec, cre->tv_nsec);
    750 	}
    751 	if (ip->i_flag & (IN_ACCESS | IN_MODIFY))
    752 		ip->i_flag |= IN_ACCESSED;
    753 	if (ip->i_flag & (IN_UPDATE | IN_CHANGE))
    754 		ip->i_flag |= IN_MODIFIED;
    755 	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE | IN_MODIFY);
    756 }
    757