Current Path : /sys/fs/hpfs/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/fs/hpfs/hpfs_alsubr.c |
/*- * Copyright (c) 1998, 1999 Semen Ustimenko (semenu@FreeBSD.org) * 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. * * 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. * * $FreeBSD: release/9.1.0/sys/fs/hpfs/hpfs_alsubr.c 111856 2003-03-04 00:04:44Z jeff $ */ #include <sys/param.h> #include <sys/systm.h> #include <sys/kernel.h> #include <sys/proc.h> #include <sys/time.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/vnode.h> #include <sys/mount.h> #include <sys/namei.h> #include <sys/malloc.h> #include <sys/bio.h> #include <sys/buf.h> #include <fs/hpfs/hpfs.h> #include <fs/hpfs/hpfs_subr.h> #define AE_DONE 0 /* Nothing to change */ #define AE_SPLIT 2 /* Split was done, ranp is valid */ int hpfs_addextentr (struct hpfsmount *, lsn_t, alleaf_t *, alnode_t *, u_long *); int hpfs_allocalsec (struct hpfsmount *, lsn_t, struct buf **); int hpfs_alblk2alsec (struct hpfsmount *, alblk_t *, alsec_t **, struct buf **); int hpfs_splitalsec (struct hpfsmount *, alsec_t *, alsec_t **, struct buf **); int hpfs_concatalsec (struct hpfsmount *, alsec_t *, alsec_t *, alnode_t *); /* * Map file offset to disk offset. hpfsnode have to be locked. */ int hpfs_hpbmap(hp, bn, bnp, runp) struct hpfsnode *hp; daddr_t bn; daddr_t *bnp; int *runp; { struct buf *bp; alblk_t * abp; alleaf_t *alp; alnode_t *anp; int error, i; dprintf(("hpfs_hpbmap(0x%x, 0x%x): ",hp->h_no, bn)); bp = NULL; abp = &hp->h_fn.fn_ab; alp = (alleaf_t *)&hp->h_fn.fn_abd; anp = (alnode_t *)&hp->h_fn.fn_abd; dive: if (abp->ab_flag & AB_NODES) { for (i=0; i<abp->ab_busycnt; i++, anp++) { dprintf(("[0x%x,0x%x] ",anp->an_nextoff,anp->an_lsn)); if (bn < anp->an_nextoff) { alsec_t *asp; dprintf(("< found | ")); if (bp) brelse(bp); error = bread(hp->h_devvp, anp->an_lsn, DEV_BSIZE, NOCRED, &bp); if (error) { printf("hpfs_hpbmap: bread error\n"); brelse(bp); return (error); } asp = (alsec_t *) bp->b_data; if (asp->as_magic != AS_MAGIC) { brelse(bp); printf("hpfs_hpbmap: " "MAGIC DOESN'T MATCH"); return (EINVAL); } abp = &asp->as_ab; alp = (alleaf_t *)&asp->as_abd; anp = (alnode_t *)&asp->as_abd; goto dive; } } } else { for (i=0; i<abp->ab_busycnt; i++, alp++) { dprintf(("[0x%x,0x%x,0x%x] ", alp->al_off,alp->al_len,alp->al_lsn)); if ((bn >= alp->al_off) && (!alp->al_len || (bn < alp->al_off + alp->al_len))) { dprintf(("found, ")); *bnp = bn - alp->al_off + alp->al_lsn; dprintf((" 0x%x ", *bnp)); if (runp != NULL) { if (alp->al_len) *runp = alp->al_off - 1 + alp->al_len - bn; else *runp = 3; /* XXX */ dprintf((" 0x%x cont", *runp)); } if (bp) brelse(bp); dprintf(("\n")); return (0); } } } dprintf(("END, notfound\n")); if (bp) brelse(bp); dprintf(("hpfs_hpbmap: offset too big\n")); return (EFBIG); } /* * Find place and preinitialize AlSec structure * AlBlk is initialized to contain AlLeafs. */ int hpfs_allocalsec ( struct hpfsmount *hpmp, lsn_t parlsn, struct buf **bpp) { alsec_t * asp; struct buf * bp; lsn_t lsn; int error; *bpp = NULL; error = hpfs_bmfblookup(hpmp, &lsn); if (error) { printf("hpfs_allocalsec: CAN'T ALLOC SPACE FOR AlSec\n"); return (error); } error = hpfs_bmmarkbusy(hpmp, lsn, 1); if (error) return (error); bp = getblk(hpmp->hpm_devvp, lsn, DEV_BSIZE, 0, 0, 0); clrbuf(bp); /* Fill AlSec info */ asp = (alsec_t *) bp->b_data; asp->as_magic = AS_MAGIC; asp->as_self = lsn; asp->as_parent = parlsn; /* Fill AlBlk */ asp->as_ab.ab_flag = 0; asp->as_ab.ab_busycnt = 0; asp->as_ab.ab_freecnt = 0x28; asp->as_ab.ab_freeoff = sizeof(alblk_t); *bpp = bp; return (0); } /* * Split AlSec structure into new allocated: * allocate new AlSec; then move second half of asp's entries in * into it; set proper flags. * * IF AlSec CONTAINS AlNodes, THEN YOU ALMOST EVERYTIME HAVE TO * FIX LAST AlNode in OLD AlSec (NEXTOFF TO BE 0xFFFFFFFF). * TOGETHER WITH FIXING ALL CHILDREN'S AlSecs (THEY HAVE GOT NEW PARENT). */ int hpfs_splitalsec ( struct hpfsmount *hpmp, alsec_t *asp, alsec_t **naspp, struct buf **nbpp) { alsec_t *nasp; struct buf *nbp; alblk_t *abp; alblk_t *nabp; int error, n1, n2, sz; error = hpfs_allocalsec(hpmp, asp->as_parent, &nbp); if (error) return (error); nasp = (alsec_t *)nbp->b_data; nabp = &nasp->as_ab; abp = &asp->as_ab; n1 = (abp->ab_busycnt + 1) / 2; n2 = (abp->ab_busycnt - n1); sz = (abp->ab_flag & AB_NODES) ? sizeof(alnode_t) : sizeof(alleaf_t); bcopy((caddr_t)abp + sizeof(alblk_t) + n1 * sz, (caddr_t)nabp + sizeof(alblk_t), n2 * sz); nabp->ab_flag = abp->ab_flag; nabp->ab_busycnt = n2; nabp->ab_freecnt = (0x1e0 / sz - n2); nabp->ab_freeoff += n2 * sz; abp->ab_busycnt -= n1; abp->ab_freecnt += n1; abp->ab_freeoff -= n1 * sz; *naspp = nasp; *nbpp = nbp; return (0); } /* * Try to concatenate two AlSec's * * Moves all entries from AlSec corresponding (as1p, aanp[1]) into * corresponding aanp[0] one. If not enought space, then return ENOSPC. * * WARNING! YOU HAVE TO FIX aanp VALUES YOURSELF LATER: * aanp[0].an_nextoff = aanp[1].an_nextoff; */ int hpfs_concatalsec ( struct hpfsmount *hpmp, alsec_t *as0p, alsec_t *as1p, alnode_t *aanp) { alblk_t *ab0p; alblk_t *ab1p; int sz; dprintf(("hpfs_concatalsec: AlSecs at 0x%x and 0x%x \n", as0p->as_self,as1p->as_self)); ab0p = &as0p->as_ab; ab1p = &as1p->as_ab; sz = (ab0p->ab_flag & AB_NODES) ? sizeof(alnode_t) : sizeof(alleaf_t); if (ab0p->ab_freecnt > ab1p->ab_busycnt) { /* * Concatenate AlSecs */ if (ab0p->ab_flag & AB_NODES) AB_LASTANP(ab0p)->an_nextoff = aanp[0].an_nextoff; bcopy (AB_ALNODE(ab1p), AB_FREEANP(ab0p), ab1p->ab_busycnt * sz); AB_ADDNREC(ab0p, sz, ab1p->ab_busycnt); return (0); } else { /* Not enought space to concatenate */ return (ENOSPC); } } /* * Transform AlBlk structure into new allocated * AlSec. * * DOESN'T SET AlSec'S PARENT LSN. */ int hpfs_alblk2alsec ( struct hpfsmount *hpmp, alblk_t *abp, alsec_t **naspp, struct buf **nbpp) { alsec_t *nasp; alblk_t *nabp; struct buf *nbp; int error, sz; error = hpfs_allocalsec(hpmp, 0, &nbp); if (error) return (error); nasp = (alsec_t *)nbp->b_data; nabp = &nasp->as_ab; sz = (abp->ab_flag & AB_NODES) ? sizeof(alnode_t) : sizeof(alleaf_t); bcopy (abp, nabp, sizeof(alblk_t) + sz * abp->ab_busycnt); nabp->ab_freecnt = 0x1e0 / sz - nabp->ab_busycnt; *naspp = nasp; *nbpp = nbp; return (0); } /* * Allocate len blocks and concatenate them to file. * If we hadn't found contignous run of len blocks, concatenate * as much as we can, and return. * */ int hpfs_addextent ( struct hpfsmount *hpmp, struct hpfsnode *hp, u_long len) { alblk_t *rabp; alnode_t ranp[2]; alleaf_t al; int error; u_long pf; /* * We don't know for now start lsn of block */ al.al_lsn = ~0; al.al_len = len; al.al_off = (hp->h_fn.fn_size + DEV_BSIZE - 1) >> DEV_BSHIFT; rabp = &hp->h_fn.fn_ab; /* Init AlBlk if this is first extent */ if (al.al_off == 0) { lsn_t nlsn; u_long nlen; dprintf(("hpfs_addextent: init AlBlk in root\n")); rabp->ab_busycnt = 0; rabp->ab_freecnt = 0x8; rabp->ab_freeoff = sizeof(alblk_t); rabp->ab_flag = 0; error = hpfs_bmlookup (hpmp, 0, hp->h_no + 1, al.al_len, &nlsn, &nlen); if (error) return (error); error = hpfs_bmmarkbusy(hpmp, nlsn, nlen); if (error) return (error); dprintf(("hpfs_addextent: new: 0x%x 0x%lx, ", nlsn, nlen)); AL_SET(AB_FREEALP(rabp), al.al_off, nlen, nlsn); AB_ADDAL(rabp); al.al_off += nlen; al.al_len -= nlen; } retry: dprintf(("hpfs_addextent: AlBlk: [0x%x, 0x%x, 0x%x] need: 0x%x\n", rabp->ab_freecnt, rabp->ab_busycnt, rabp->ab_flag, al.al_len)); while ((al.al_len) && (rabp->ab_freecnt > 0)) { if (rabp->ab_flag & AB_NODES) { alnode_t *anp; /* * This is level containing AlNodes, so try to * insert recursively into last entry. */ anp = AB_LASTANP(rabp); dprintf(("hpfs_addextent: AlNode: [0x%x,0x%x] \n", anp->an_nextoff,anp->an_lsn)); /* * Try to insert... */ error = hpfs_addextentr (hpmp, anp->an_lsn, &al, ranp, &pf); if (error) { printf("hpfs_addextent: FAILED %d\n",error); return (error); } switch (pf) { case AE_SPLIT: dprintf(("hpfs_addextent: successful (split)\n")); /* * Then hpfs_addextentr has split tree below, now * we need to fix this level. Particulary: * fix last AlNode and add another one. */ bcopy(ranp, AB_LASTANP(rabp), sizeof(alnode_t) * 2); AB_ADDAN(rabp); break; default: case AE_DONE: dprintf(("hpfs_addextent: successful\n")); break; } } else { alleaf_t *alp; alp = AB_LASTALP(rabp); dprintf(("hpfs_addextent: AlLeaf: [0x%x,0x%x,0x%x] \n", alp->al_off,alp->al_len,alp->al_lsn)); /* Check if we trying to add in right place */ if (alp->al_off + alp->al_len == al.al_off) { lsn_t nlsn; u_long nlen; /* * Search bitmap for block begining from * alp->al_lsn + alp->al_len and long of ralp->al_len */ error = hpfs_bmlookup (hpmp, 0, alp->al_lsn + alp->al_len, al.al_len, &nlsn, &nlen); if (error) return (error); error = hpfs_bmmarkbusy(hpmp, nlsn, nlen); if (error) return (error); dprintf(("hpfs_addextent: new: 0x%x 0x%lx, ", nlsn, nlen)); if (alp->al_lsn + alp->al_len == nlsn) { dprintf(("extended existed leaf\n")); alp->al_len += nlen; } else { dprintf(("created new leaf\n")); AL_SET(AB_FREEALP(rabp), al.al_off, nlen, nlsn); AB_ADDAL(rabp); } al.al_off += nlen; al.al_len -= nlen; } else { printf("hpfs_addextent: INTERNAL INCONSISTENCE\n"); return (EINVAL); } } } /* * Move AlBlk contain to new AlSec (it will fit more * entries) if overflowed (no more free entries). */ if (rabp->ab_freecnt <= 0) { struct buf *nbp; alsec_t * nrasp; dprintf(("hpfs_addextent: overflow, convt\n")); /* * Convert AlBlk to new AlSec, it will set * AB_FNPARENT also. */ rabp->ab_flag |= AB_FNPARENT; error = hpfs_alblk2alsec (hpmp, rabp, &nrasp, &nbp); if (error) { printf("hpfs_addextent: CAN'T CONVT\n"); return (error); } nrasp->as_parent = hp->h_no; /* * Scan all childrens (if exist), set new parent and * clean their AB_FNPARENT flag. */ if (rabp->ab_flag & AB_NODES) { int i; alsec_t * asp; alnode_t * anp; struct buf * bp; anp = AB_ALNODE(rabp); for (i=0; i<rabp->ab_busycnt; i++) { error = hpfs_breadalsec(hpmp, anp->an_lsn, &bp); if (error) return (error); asp = (alsec_t *)bp->b_data; asp->as_ab.ab_flag &= ~AB_FNPARENT; asp->as_parent = nrasp->as_self; bdwrite(bp); anp ++; } } /* Convert AlBlk to contain AlNodes */ rabp->ab_flag = AB_NODES; rabp->ab_busycnt = 0; rabp->ab_freecnt = 0xC; rabp->ab_freeoff = sizeof(alblk_t); /* Add AlNode for new allocated AlSec */ AN_SET(AB_FREEANP(rabp), ~0, nrasp->as_self); AB_ADDAN(rabp); bdwrite(nbp); } if (al.al_len) { dprintf(("hpfs_addextent: root retry\n")); goto retry; } return (0); } /* * Descent down to the end of tree, then search for * ralp->len contignous run begining from last run's end and * concatenate new block! If we can't find one, then... */ int hpfs_addextentr ( struct hpfsmount *hpmp, /* Mix info */ lsn_t rlsn, /* LSN containing AlSec */ alleaf_t *ralp, /* AlLeaf to insert */ alnode_t *ranp, /* New AlNodes' values */ u_long *resp) /* Mix returning info */ { struct buf *rbp; alsec_t *rasp; alblk_t *rabp; alleaf_t *alp; alnode_t *anp; int error; u_long pf; u_long wb; *resp = 0; dprintf(("hpfs_addextentr: AlSec at 0x%x\n", rlsn)); error = hpfs_breadalsec(hpmp, rlsn, &rbp); if (error) return (error); rasp = (alsec_t *)rbp->b_data; rabp = &rasp->as_ab; wb = 0; dprintf(("hpfs_addextentr: AlBlk: [0x%x, 0x%x, 0x%x]\n", rabp->ab_freecnt, rabp->ab_busycnt, rabp->ab_flag)); while ((ralp->al_len) && (rabp->ab_freecnt > 0)) { if (rabp->ab_flag & AB_NODES) { /* * This is level containing AlNodes, so try to * insert recursively into last entry. */ anp = AB_LASTANP(rabp); dprintf(("hpfs_addextentr: AlNode: [0x%x,0x%x] \n", anp->an_nextoff,anp->an_lsn)); /* * Try to insert... */ error = hpfs_addextentr (hpmp, anp->an_lsn, ralp, ranp, &pf); if (error) { printf("hpfs_addextentr: FAILED %d\n",error); goto fail; } switch (pf) { case AE_SPLIT: dprintf(("hpfs_addextentr: successful (split)\n")); /* * Then hpfs_addextentr has split tree below, now * we need to fix this level. Particulary: * fix last AlNode and add another one. */ bcopy(ranp, AB_LASTANP(rabp), sizeof(alnode_t) * 2); AB_ADDAN(rabp); wb = 1; break; default: case AE_DONE: dprintf(("hpfs_addextentr: successful\n")); break; } } else { alp = AB_LASTALP(rabp); dprintf(("hpfs_addextentr: AlLeaf: [0x%x,0x%x,0x%x] \n", alp->al_off,alp->al_len,alp->al_lsn)); /* Check if we trying to add in right place */ if (alp->al_off + alp->al_len == ralp->al_off) { lsn_t nlsn; u_long nlen; /* * Search bitmap for block begining from * alp->al_lsn + alp->al_len and long of ralp->al_len */ error = hpfs_bmlookup (hpmp, 0, alp->al_lsn + alp->al_len, ralp->al_len, &nlsn, &nlen); if (error) goto fail; error = hpfs_bmmarkbusy(hpmp, nlsn, nlen); if (error) goto fail; dprintf(("hpfs_addextentr: new: 0x%x 0x%lx, ", nlsn, nlen)); /* * If ending of existed entry fits the * begining of the extent being added, * then we add concatenate two extents. */ if (alp->al_lsn + alp->al_len == nlsn) { dprintf(("concat\n")); alp->al_len += nlen; } else { dprintf(("created new leaf\n")); AL_SET(AB_FREEALP(rabp), ralp->al_off, nlen, nlsn); AB_ADDAL(rabp); } ralp->al_len -= nlen; ralp->al_off += nlen; } else { printf("hpfs_addextentr: INTERNAL INCONSISTENCE\n"); error = (EINVAL); goto fail; } } } /* * Split AlBlk if overflowed. */ if (rabp->ab_freecnt <= 0) { struct buf *nbp; alsec_t * nrasp; dprintf(("hpfs_addextentr: overflow, split\n")); error = hpfs_splitalsec (hpmp, rasp, &nrasp, &nbp); if (error) { printf("hpfs_addextent: CAN'T SPLIT\n"); goto fail; } if (rabp->ab_flag & AB_NODES) { int i; alsec_t * asp; alnode_t * anp; struct buf * bp; ranp[0].an_nextoff = AB_LASTANP(&rasp->as_ab)->an_nextoff; /* We need to set left subtree's last entry * offset to 0xFFFFFFFF for OS/2 to be able * to read our files. It treats absence of * 0xFFFFFFFF as error. */ AB_LASTANP(&rasp->as_ab)->an_nextoff = ~0; /* We need to fix new allocated AlSec's * children, becouse their parent has changed. */ anp = AB_ALNODE(&nrasp->as_ab); for (i=0; i<nrasp->as_ab.ab_busycnt; i++) { error = hpfs_breadalsec(hpmp, anp->an_lsn, &bp); if (error) { brelse(nbp); goto fail; } asp = (alsec_t *)bp->b_data; asp->as_parent = nrasp->as_self; bdwrite(bp); anp ++; } } else { ranp[0].an_nextoff = AB_ALLEAF(&nrasp->as_ab)->al_off; } ranp[0].an_lsn = rasp->as_self; ranp[1].an_nextoff = ~0; ranp[1].an_lsn = nrasp->as_self; bdwrite(nbp); *resp = AE_SPLIT; wb = 1; } if (wb) bdwrite (rbp); else brelse(rbp); return (0); fail: brelse(rbp); return (error); } /* * Recursive routine walking down the b-tree and deallocating all * extents above bn. Returns *resp != 0 if alblk was totally * deallocated and may be freed. Tries to keep b-tree. * * (XXXX) NOTE! THIS ROUTINE WILL NEVER DECREMENT DEPTH OF * THE TREE. */ int hpfs_truncatealblk ( struct hpfsmount *hpmp, alblk_t *abp, lsn_t bn, int *resp) { int error; alleaf_t *alp; alnode_t *anp; alsec_t *asp; struct buf *bp; dprintf(("hpfs_truncatealblk: AlBlk: [0x%x,0x%x, 0x%x]\n", abp->ab_freecnt, abp->ab_busycnt, abp->ab_flag)); if (abp->ab_flag & AB_NODES) { /* * Scan array of AlNodes backward, * diving in recursion if needed */ anp = AB_LASTANP(abp); while (abp->ab_busycnt && (bn <= anp->an_nextoff)) { dprintf(("hpfs_truncatealblk: AlNode: [0x%x,0x%x] \n", anp->an_nextoff,anp->an_lsn)); error = hpfs_breadalsec(hpmp, anp->an_lsn, &bp); if (error) return (error); asp = (alsec_t *)bp->b_data; error = hpfs_truncatealblk (hpmp, &asp->as_ab, bn, resp); if (error) { brelse(bp); return (error); } if (*resp) { brelse (bp); error = hpfs_bmmarkfree(hpmp, anp->an_lsn, 1); if (error) return (error); AB_RMAN(abp); anp --; } else { /* * We have deallocated some entries, some space * migth been freed, then try to concat two * last AlSec. */ anp->an_nextoff = ~0; if (abp->ab_busycnt >= 2) { alsec_t *as0p; struct buf *b0p; error = hpfs_breadalsec(hpmp, (anp-1)->an_lsn, &b0p); if (error) return (error); as0p = (alsec_t *)b0p->b_data; error = hpfs_concatalsec(hpmp, as0p, asp, anp - 1); if (error == ENOSPC) { /* Not enought space */ brelse (b0p); bdwrite (bp); } else if (error == 0) { /* All OK */ (anp-1)->an_nextoff = anp->an_nextoff; bdwrite (b0p); brelse (bp); error = hpfs_bmmarkfree(hpmp, anp->an_lsn, 1); if (error) return (error); AB_RMAN(abp); } else { /* True error */ brelse (b0p); brelse (bp); return (error); } } else { /* Nowhere to concatenate */ bdwrite (bp); } /* There can not be any more entries * over greater bn, becouse last AlSec * wasn't freed totally. So go out. */ break; } } if (abp->ab_busycnt == 0) *resp = 1; else *resp = 0; } else { /* * Scan array of AlLeafs backward, * free all above bn. */ alp = AB_LASTALP(abp); while (abp->ab_busycnt && (bn < alp->al_off + alp->al_len)){ dprintf(("hpfs_truncatealblk: AlLeaf: [0x%x,0x%x,0x%x] \n", alp->al_off,alp->al_len,alp->al_lsn)); if (bn <= alp->al_off) { error = hpfs_bmmarkfree(hpmp, alp->al_lsn, alp->al_len); if (error) return (error); AB_RMAL(abp); alp --; } else if ((bn > alp->al_off) && (bn < alp->al_off + alp->al_len)){ error = hpfs_bmmarkfree(hpmp, alp->al_lsn + bn - alp->al_off, alp->al_len - bn + alp->al_off); if (error) return (error); alp->al_len = bn - alp->al_off; break; } else break; } } /* Signal parent deallocation, if need */ if (abp->ab_busycnt == 0) *resp = 1; else *resp = 0; return (0); }