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lfs_balloc.c revision 1.53
      1 /*	$NetBSD: lfs_balloc.c,v 1.53 2005/04/14 00:44:17 perseant Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999, 2000, 2001, 2002, 2003 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Konrad E. Schroder <perseant (at) hhhh.org>.
      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  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the NetBSD
     21  *	Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 /*
     39  * Copyright (c) 1989, 1991, 1993
     40  *	The Regents of the University of California.  All rights reserved.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. Neither the name of the University nor the names of its contributors
     51  *    may be used to endorse or promote products derived from this software
     52  *    without specific prior written permission.
     53  *
     54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     64  * SUCH DAMAGE.
     65  *
     66  *	@(#)lfs_balloc.c	8.4 (Berkeley) 5/8/95
     67  */
     68 
     69 #include <sys/cdefs.h>
     70 __KERNEL_RCSID(0, "$NetBSD: lfs_balloc.c,v 1.53 2005/04/14 00:44:17 perseant Exp $");
     71 
     72 #if defined(_KERNEL_OPT)
     73 #include "opt_quota.h"
     74 #endif
     75 
     76 #include <sys/param.h>
     77 #include <sys/systm.h>
     78 #include <sys/buf.h>
     79 #include <sys/proc.h>
     80 #include <sys/vnode.h>
     81 #include <sys/mount.h>
     82 #include <sys/resourcevar.h>
     83 #include <sys/trace.h>
     84 #include <sys/malloc.h>
     85 
     86 #include <miscfs/specfs/specdev.h>
     87 
     88 #include <ufs/ufs/quota.h>
     89 #include <ufs/ufs/inode.h>
     90 #include <ufs/ufs/ufsmount.h>
     91 #include <ufs/ufs/ufs_extern.h>
     92 
     93 #include <ufs/lfs/lfs.h>
     94 #include <ufs/lfs/lfs_extern.h>
     95 
     96 #include <uvm/uvm.h>
     97 
     98 int lfs_fragextend(struct vnode *, int, int, daddr_t, struct buf **, struct ucred *);
     99 
    100 u_int64_t locked_fakequeue_count;
    101 extern int lfs_blist_hw;
    102 extern int lfs_blist_total;    /* # entries in hash table */
    103 extern int lfs_blist_maxdepth; /* Hash max depth */
    104 extern LIST_HEAD(, lbnentry) *lfs_blist;
    105 
    106 /*
    107  * Allocate a block, and to inode and filesystem block accounting for it
    108  * and for any indirect blocks the may need to be created in order for
    109  * this block to be created.
    110  *
    111  * Blocks which have never been accounted for (i.e., which "do not exist")
    112  * have disk address 0, which is translated by ufs_bmap to the special value
    113  * UNASSIGNED == -1, as in the historical UFS.
    114  *
    115  * Blocks which have been accounted for but which have not yet been written
    116  * to disk are given the new special disk address UNWRITTEN == -2, so that
    117  * they can be differentiated from completely new blocks.
    118  */
    119 /* VOP_BWRITE NIADDR+2 times */
    120 int
    121 lfs_balloc(void *v)
    122 {
    123 	struct vop_balloc_args /* {
    124 		struct vnode *a_vp;
    125 		off_t a_startoffset;
    126 		int a_size;
    127 		struct ucred *a_cred;
    128 		int a_flags;
    129 		struct buf *a_bpp;
    130 	} */ *ap = v;
    131 	struct vnode *vp;
    132 	int offset;
    133 	u_long iosize;
    134 	daddr_t daddr, idaddr;
    135 	struct buf *ibp, *bp, **bpp;
    136 	struct inode *ip;
    137 	struct lfs *fs;
    138 	struct indir indirs[NIADDR+2], *idp;
    139 	daddr_t	lbn, lastblock;
    140 	int bb, bcount;
    141 	int error, frags, i, nsize, osize, num;
    142 
    143 	vp = ap->a_vp;
    144 	ip = VTOI(vp);
    145 	fs = ip->i_lfs;
    146 	offset = blkoff(fs, ap->a_startoffset);
    147 	iosize = ap->a_size;
    148 	KASSERT(iosize <= fs->lfs_bsize);
    149 	lbn = lblkno(fs, ap->a_startoffset);
    150 	/* (void)lfs_check(vp, lbn, 0); */
    151 	bpp = ap->a_bpp;
    152 
    153 	ASSERT_MAYBE_SEGLOCK(fs);
    154 
    155 	/*
    156 	 * Three cases: it's a block beyond the end of file, it's a block in
    157 	 * the file that may or may not have been assigned a disk address or
    158 	 * we're writing an entire block.
    159 	 *
    160 	 * Note, if the daddr is UNWRITTEN, the block already exists in
    161 	 * the cache (it was read or written earlier).	If so, make sure
    162 	 * we don't count it as a new block or zero out its contents. If
    163 	 * it did not, make sure we allocate any necessary indirect
    164 	 * blocks.
    165 	 *
    166 	 * If we are writing a block beyond the end of the file, we need to
    167 	 * check if the old last block was a fragment.	If it was, we need
    168 	 * to rewrite it.
    169 	 */
    170 
    171 	if (bpp)
    172 		*bpp = NULL;
    173 
    174 	/* Check for block beyond end of file and fragment extension needed. */
    175 	lastblock = lblkno(fs, ip->i_size);
    176 	if (lastblock < NDADDR && lastblock < lbn) {
    177 		osize = blksize(fs, ip, lastblock);
    178 		if (osize < fs->lfs_bsize && osize > 0) {
    179 			if ((error = lfs_fragextend(vp, osize, fs->lfs_bsize,
    180 						    lastblock,
    181 						    (bpp ? &bp : NULL),
    182 						    ap->a_cred)))
    183 				return (error);
    184 			ip->i_ffs1_size = ip->i_size =
    185 			    (lastblock + 1) * fs->lfs_bsize;
    186 			uvm_vnp_setsize(vp, ip->i_size);
    187 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
    188 			if (bpp)
    189 				(void) VOP_BWRITE(bp);
    190 		}
    191 	}
    192 
    193 	/*
    194 	 * If the block we are writing is a direct block, it's the last
    195 	 * block in the file, and offset + iosize is less than a full
    196 	 * block, we can write one or more fragments.  There are two cases:
    197 	 * the block is brand new and we should allocate it the correct
    198 	 * size or it already exists and contains some fragments and
    199 	 * may need to extend it.
    200 	 */
    201 	if (lbn < NDADDR && lblkno(fs, ip->i_size) <= lbn) {
    202 		osize = blksize(fs, ip, lbn);
    203 		nsize = fragroundup(fs, offset + iosize);
    204 		if (lblktosize(fs, lbn) >= ip->i_size) {
    205 			/* Brand new block or fragment */
    206 			frags = numfrags(fs, nsize);
    207 			bb = fragstofsb(fs, frags);
    208 			if (!ISSPACE(fs, bb, ap->a_cred))
    209 				return ENOSPC;
    210 			if (bpp) {
    211 				*ap->a_bpp = bp = getblk(vp, lbn, nsize, 0, 0);
    212 				bp->b_blkno = UNWRITTEN;
    213 				if (ap->a_flags & B_CLRBUF)
    214 					clrbuf(bp);
    215 			}
    216 			ip->i_lfs_effnblks += bb;
    217 			simple_lock(&fs->lfs_interlock);
    218 			fs->lfs_bfree -= bb;
    219 			simple_unlock(&fs->lfs_interlock);
    220 			ip->i_ffs1_db[lbn] = UNWRITTEN;
    221 		} else {
    222 			if (nsize <= osize) {
    223 				/* No need to extend */
    224 				if (bpp && (error = bread(vp, lbn, osize, NOCRED, &bp)))
    225 					return error;
    226 			} else {
    227 				/* Extend existing block */
    228 				if ((error =
    229 				     lfs_fragextend(vp, osize, nsize, lbn,
    230 						    (bpp ? &bp : NULL),
    231 						    ap->a_cred)))
    232 					return error;
    233 			}
    234 			if (bpp)
    235 				*bpp = bp;
    236 		}
    237 		return 0;
    238 	}
    239 
    240 	error = ufs_bmaparray(vp, lbn, &daddr, &indirs[0], &num, NULL, NULL);
    241 	if (error)
    242 		return (error);
    243 
    244 	daddr = (daddr_t)((int32_t)daddr); /* XXX ondisk32 */
    245 	KASSERT(daddr <= LFS_MAX_DADDR);
    246 
    247 	/*
    248 	 * Do byte accounting all at once, so we can gracefully fail *before*
    249 	 * we start assigning blocks.
    250 	 */
    251 	bb = VFSTOUFS(vp->v_mount)->um_seqinc;
    252 	bcount = 0;
    253 	if (daddr == UNASSIGNED) {
    254 		bcount = bb;
    255 	}
    256 	for (i = 1; i < num; ++i) {
    257 		if (!indirs[i].in_exists) {
    258 			bcount += bb;
    259 		}
    260 	}
    261 	if (ISSPACE(fs, bcount, ap->a_cred)) {
    262 		simple_lock(&fs->lfs_interlock);
    263 		fs->lfs_bfree -= bcount;
    264 		simple_unlock(&fs->lfs_interlock);
    265 		ip->i_lfs_effnblks += bcount;
    266 	} else {
    267 		return ENOSPC;
    268 	}
    269 
    270 	if (daddr == UNASSIGNED) {
    271 		if (num > 0 && ip->i_ffs1_ib[indirs[0].in_off] == 0) {
    272 			ip->i_ffs1_ib[indirs[0].in_off] = UNWRITTEN;
    273 		}
    274 
    275 		/*
    276 		 * Create new indirect blocks if necessary
    277 		 */
    278 		if (num > 1) {
    279 			idaddr = ip->i_ffs1_ib[indirs[0].in_off];
    280 			for (i = 1; i < num; ++i) {
    281 				ibp = getblk(vp, indirs[i].in_lbn,
    282 				    fs->lfs_bsize, 0,0);
    283 				if (!indirs[i].in_exists) {
    284 					clrbuf(ibp);
    285 					ibp->b_blkno = UNWRITTEN;
    286 				} else if (!(ibp->b_flags & (B_DELWRI | B_DONE))) {
    287 					ibp->b_blkno = fsbtodb(fs, idaddr);
    288 					ibp->b_flags |= B_READ;
    289 					VOP_STRATEGY(vp, ibp);
    290 					biowait(ibp);
    291 				}
    292 				/*
    293 				 * This block exists, but the next one may not.
    294 				 * If that is the case mark it UNWRITTEN to keep
    295 				 * the accounting straight.
    296 				 */
    297 				/* XXX ondisk32 */
    298 				if (((int32_t *)ibp->b_data)[indirs[i].in_off] == 0)
    299 					((int32_t *)ibp->b_data)[indirs[i].in_off] =
    300 						UNWRITTEN;
    301 				/* XXX ondisk32 */
    302 				idaddr = ((int32_t *)ibp->b_data)[indirs[i].in_off];
    303 #ifdef DEBUG
    304 				if (vp == fs->lfs_ivnode) {
    305 					LFS_ENTER_LOG("balloc", __FILE__,
    306 						__LINE__, indirs[i].in_lbn,
    307 						ibp->b_flags, curproc->p_pid);
    308 				}
    309 #endif
    310 				if ((error = VOP_BWRITE(ibp)))
    311 					return error;
    312 			}
    313 		}
    314 	}
    315 
    316 
    317 	/*
    318 	 * Get the existing block from the cache, if requested.
    319 	 */
    320 	frags = fsbtofrags(fs, bb);
    321 	if (bpp)
    322 		*bpp = bp = getblk(vp, lbn, blksize(fs, ip, lbn), 0, 0);
    323 
    324 	/*
    325 	 * Do accounting on blocks that represent pages.
    326 	 */
    327 	if (!bpp)
    328 		lfs_register_block(vp, lbn);
    329 
    330 	/*
    331 	 * The block we are writing may be a brand new block
    332 	 * in which case we need to do accounting.
    333 	 *
    334 	 * We can tell a truly new block because ufs_bmaparray will say
    335 	 * it is UNASSIGNED.  Once we allocate it we will assign it the
    336 	 * disk address UNWRITTEN.
    337 	 */
    338 	if (daddr == UNASSIGNED) {
    339 		if (bpp) {
    340 			if (ap->a_flags & B_CLRBUF)
    341 				clrbuf(bp);
    342 
    343 			/* Note the new address */
    344 			bp->b_blkno = UNWRITTEN;
    345 		}
    346 
    347 		switch (num) {
    348 		    case 0:
    349 			ip->i_ffs1_db[lbn] = UNWRITTEN;
    350 			break;
    351 		    case 1:
    352 			ip->i_ffs1_ib[indirs[0].in_off] = UNWRITTEN;
    353 			break;
    354 		    default:
    355 			idp = &indirs[num - 1];
    356 			if (bread(vp, idp->in_lbn, fs->lfs_bsize, NOCRED,
    357 				  &ibp))
    358 				panic("lfs_balloc: bread bno %lld",
    359 				    (long long)idp->in_lbn);
    360 			/* XXX ondisk32 */
    361 			((int32_t *)ibp->b_data)[idp->in_off] = UNWRITTEN;
    362 #ifdef DEBUG
    363 			if (vp == fs->lfs_ivnode) {
    364 				LFS_ENTER_LOG("balloc", __FILE__,
    365 					__LINE__, idp->in_lbn,
    366 					ibp->b_flags, curproc->p_pid);
    367 			}
    368 #endif
    369 			VOP_BWRITE(ibp);
    370 		}
    371 	} else if (bpp && !(bp->b_flags & (B_DONE|B_DELWRI))) {
    372 		/*
    373 		 * Not a brand new block, also not in the cache;
    374 		 * read it in from disk.
    375 		 */
    376 		if (iosize == fs->lfs_bsize)
    377 			/* Optimization: I/O is unnecessary. */
    378 			bp->b_blkno = daddr;
    379 		else {
    380 			/*
    381 			 * We need to read the block to preserve the
    382 			 * existing bytes.
    383 			 */
    384 			bp->b_blkno = daddr;
    385 			bp->b_flags |= B_READ;
    386 			VOP_STRATEGY(vp, bp);
    387 			return (biowait(bp));
    388 		}
    389 	}
    390 
    391 	return (0);
    392 }
    393 
    394 /* VOP_BWRITE 1 time */
    395 int
    396 lfs_fragextend(struct vnode *vp, int osize, int nsize, daddr_t lbn, struct buf **bpp, struct ucred *cred)
    397 {
    398 	struct inode *ip;
    399 	struct lfs *fs;
    400 	long bb;
    401 	int error;
    402 	extern long locked_queue_bytes;
    403 	size_t obufsize;
    404 
    405 	ip = VTOI(vp);
    406 	fs = ip->i_lfs;
    407 	bb = (long)fragstofsb(fs, numfrags(fs, nsize - osize));
    408 	error = 0;
    409 
    410 	ASSERT_DUNNO_SEGLOCK(fs);
    411 
    412 	/*
    413 	 * Get the seglock so we don't enlarge blocks while a segment
    414 	 * is being written.  If we're called with bpp==NULL, though,
    415 	 * we are only pretending to change a buffer, so we don't have to
    416 	 * lock.
    417 	 */
    418     top:
    419 	if (bpp) {
    420 		lockmgr(&fs->lfs_fraglock, LK_SHARED, 0);
    421 		LFS_DEBUG_COUNTLOCKED("frag");
    422 	}
    423 
    424 	if (!ISSPACE(fs, bb, cred)) {
    425 		error = ENOSPC;
    426 		goto out;
    427 	}
    428 
    429 	/*
    430 	 * If we are not asked to actually return the block, all we need
    431 	 * to do is allocate space for it.  UBC will handle dirtying the
    432 	 * appropriate things and making sure it all goes to disk.
    433 	 * Don't bother to read in that case.
    434 	 */
    435 	if (bpp && (error = bread(vp, lbn, osize, NOCRED, bpp))) {
    436 		brelse(*bpp);
    437 		goto out;
    438 	}
    439 #ifdef QUOTA
    440 	if ((error = chkdq(ip, bb, cred, 0))) {
    441 		if (bpp)
    442 			brelse(*bpp);
    443 		goto out;
    444 	}
    445 #endif
    446 	/*
    447 	 * Adjust accounting for lfs_avail.  If there's not enough room,
    448 	 * we will have to wait for the cleaner, which we can't do while
    449 	 * holding a block busy or while holding the seglock.  In that case,
    450 	 * release both and start over after waiting.
    451 	 */
    452 
    453 	if (bpp && ((*bpp)->b_flags & B_DELWRI)) {
    454 		if (!lfs_fits(fs, bb)) {
    455 			if (bpp)
    456 				brelse(*bpp);
    457 #ifdef QUOTA
    458 			chkdq(ip, -bb, cred, 0);
    459 #endif
    460 			lockmgr(&fs->lfs_fraglock, LK_RELEASE, 0);
    461 			lfs_availwait(fs, bb);
    462 			goto top;
    463 		}
    464 		fs->lfs_avail -= bb;
    465 	}
    466 
    467 	simple_lock(&fs->lfs_interlock);
    468 	fs->lfs_bfree -= bb;
    469 	simple_unlock(&fs->lfs_interlock);
    470 	ip->i_lfs_effnblks += bb;
    471 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
    472 
    473 	if (bpp) {
    474 		obufsize = (*bpp)->b_bufsize;
    475 		allocbuf(*bpp, nsize, 1);
    476 
    477 		/* Adjust locked-list accounting */
    478 		if (((*bpp)->b_flags & (B_LOCKED | B_CALL)) == B_LOCKED) {
    479 			simple_lock(&lfs_subsys_lock);
    480 			locked_queue_bytes += (*bpp)->b_bufsize - obufsize;
    481 			simple_unlock(&lfs_subsys_lock);
    482 		}
    483 
    484 		bzero((char *)((*bpp)->b_data) + osize, (u_int)(nsize - osize));
    485 	}
    486 
    487     out:
    488 	if (bpp) {
    489 		lockmgr(&fs->lfs_fraglock, LK_RELEASE, 0);
    490 	}
    491 	return (error);
    492 }
    493 
    494 static __inline unsigned int
    495 lfs_blist_hash(struct lfs *fs, struct inode *ip, daddr_t lbn)
    496 {
    497         return ((intptr_t)fs ^ ip->i_number ^ lbn) & (lfs_blist_hw - 1);
    498 }
    499 
    500 #define HASH_HEADER(ip, hash) &(lfs_blist[hash])
    501 
    502 /*
    503  * Record this lbn as being "write pending".  We used to have this information
    504  * on the buffer headers, but since pages don't have buffer headers we
    505  * record it here instead.
    506  */
    507 void
    508 lfs_register_block(struct vnode *vp, daddr_t lbn)
    509 {
    510 	struct lfs *fs;
    511 	struct inode *ip;
    512 	struct lbnentry *lbp;
    513 	unsigned int hash, depth;
    514 
    515 	ip = VTOI(vp);
    516 
    517 	/* Don't count metadata */
    518 	if (lbn < 0 || vp->v_type != VREG || ip->i_number == LFS_IFILE_INUM)
    519 		return;
    520 
    521 	fs = ip->i_lfs;
    522 
    523 	ASSERT_NO_SEGLOCK(fs);
    524 
    525 	/* If no space, wait for the cleaner */
    526 	lfs_availwait(fs, btofsb(fs, 1 << fs->lfs_bshift));
    527 
    528 	hash = lfs_blist_hash(fs, ip, lbn);
    529 	depth = 0;
    530 	LIST_FOREACH(lbp, HASH_HEADER(ip, hash), entry) {
    531 		if (lbp->lbn == lbn && lbp->vp == vp && lbp->fs == fs)
    532 			return;
    533 		++depth;
    534 	}
    535 
    536 	lbp = (struct lbnentry *)pool_get(&lfs_lbnentry_pool, PR_WAITOK);
    537 	lbp->lbn = lbn;
    538 	lbp->vp = vp;
    539 	lbp->fs = fs;
    540 	if (depth > lfs_blist_maxdepth)
    541 		lfs_blist_maxdepth = depth;
    542 	++lfs_blist_total;
    543 	LIST_INSERT_HEAD(HASH_HEADER(ip, hash), lbp, entry);
    544 
    545 	simple_lock(&fs->lfs_interlock);
    546 	fs->lfs_favail += btofsb(fs, (1 << fs->lfs_bshift));
    547 	++locked_fakequeue_count;
    548 	simple_unlock(&fs->lfs_interlock);
    549 }
    550 
    551 static void
    552 lfs_do_deregister(struct lfs *fs, struct inode *ip, struct lbnentry *lbp)
    553 {
    554 	ASSERT_MAYBE_SEGLOCK(fs);
    555 
    556 	LIST_REMOVE(lbp, entry);
    557 	--lfs_blist_total;
    558 	pool_put(&lfs_lbnentry_pool, lbp);
    559 	simple_lock(&fs->lfs_interlock);
    560 	if (fs->lfs_favail > btofsb(fs, (1 << fs->lfs_bshift)))
    561 		fs->lfs_favail -= btofsb(fs, (1 << fs->lfs_bshift));
    562 	simple_lock(&lfs_subsys_lock);
    563 	if (locked_fakequeue_count > 0)
    564 		--locked_fakequeue_count;
    565 	simple_unlock(&lfs_subsys_lock);
    566 	simple_unlock(&fs->lfs_interlock);
    567 }
    568 
    569 void
    570 lfs_deregister_block(struct vnode *vp, daddr_t lbn)
    571 {
    572 	struct lfs *fs;
    573 	struct inode *ip;
    574 	struct lbnentry *lbp;
    575 	unsigned int hash;
    576 
    577 	ip = VTOI(vp);
    578 
    579 	/* Don't count metadata */
    580 	if (lbn < 0 || vp->v_type != VREG || ip->i_number == LFS_IFILE_INUM)
    581 		return;
    582 
    583 	fs = ip->i_lfs;
    584 	hash = lfs_blist_hash(fs, ip, lbn);
    585 	LIST_FOREACH(lbp, HASH_HEADER(vp, hash), entry) {
    586 		if (lbp->lbn == lbn && lbp->vp == vp && lbp->fs == fs)
    587 			break;
    588 	}
    589 	if (lbp == NULL)
    590 		return;
    591 
    592 	lfs_do_deregister(fs, ip, lbp);
    593 }
    594