ref: c881e33e8ed668f4d5a2102c113e3edb1ea80d44
dir: /sys/src/cmd/hjfs/fs1.c/
#include <u.h> #include <libc.h> #include <thread.h> #include <fcall.h> #include "dat.h" #include "fns.h" int chref(Fs *fs, uvlong r, int stat) { uvlong i; int j; ulong rc; Buf *c; i = fs->fstart + r / REFPERBLK; j = r % REFPERBLK; c = getbuf(fs->d, i, TREF, 0); if(c == nil) return -1; if(stat < 0 && c->refs[j] < -stat) c->refs[j] = 0; else c->refs[j] += stat; rc = c->refs[j]; if(stat != 0) c->op |= BDELWRI; putbuf(c); return rc; } static int qidcmp(Qid *a, Qid *b) { if(a->type != b->type) return 1; if(a->path != b->path){ /* special case for dump, this is ok */ if(a->path==ROOTQID && b->path==DUMPROOTQID) return 0; return 1; } return 0; } Dentry* getdent(FLoc *l, Buf *b) { Dentry *d; d = &b->de[l->deind]; if((d->mode & (DGONE | DALLOC)) == 0){ dprint("getdent: file gone, d=%llux, l=%llud/%d %llux, callerpc %#p\n", d->path, l->blk, l->deind, l->path, getcallerpc(&l)); werrstr("phase error -- directory entry for nonexistent file"); return nil; } if(qidcmp(d, l) != 0){ dprint("getdent: wrong qid d=%llux != l=%llud/%d %llux, callerpc %#p\n", d->path, l->blk, l->deind, l->path, getcallerpc(&l)); werrstr("phase error -- qid mismatch"); return nil; } return d; } int getfree(Fs *fs, uvlong *r) { Dev *d; Buf *b; uvlong i, l, e; int j, have; d = fs->d; while(nbrecv(fs->freelist, &l) > 0){ i = fs->fstart + l / REFPERBLK; j = l % REFPERBLK; b = getbuf(d, i, TREF, 0); if(b != nil){ if(b->refs[j] == 0){ b->refs[j] = 1; *r = l; goto found; } putbuf(b); } } b = getbuf(d, SUPERBLK, TSUPERBLOCK, 0); if(b == nil) { werrstr("could not find superblock"); return -1; } e = b->sb.fend; putbuf(b); have = 0; for(l = 0, i = fs->fstart; i < e; i++){ b = getbuf(d, i, TREF, 0); if(b == nil){ l += REFPERBLK; continue; } for(j = 0; j < REFPERBLK; j++, l++) if(b->refs[j] == 0){ if(!have){ b->refs[j] = 1; *r = l; have = 1; }else if(nbsend(fs->freelist, &l) <= 0) goto found; } if(have) goto found; putbuf(b); } werrstr("disk full"); return -1; found: b->op |= BDELWRI; putbuf(b); return 1; } int putfree(Fs *fs, uvlong r) { int rc; rc = chref(fs, r, -1); if(rc < 0) return -1; if(rc == 0) nbsend(fs->freelist, &r); return 1; } static void createroot(Fs *fs) { uvlong r; Buf *c; Dentry *d; if(getfree(fs, &r) < 0) sysfatal("ream: getfree: %r"); c = getbuf(fs->d, r, TDENTRY, 1); if(c == nil) error: sysfatal("ream: getbuf: %r"); memset(c->de, 0, sizeof(c->de)); d = &c->de[0]; strcpy(d->name, "/"); d->mode = DALLOC | 0775; d->path = ROOTQID; d->type = QTDIR; d->uid = -1; d->muid = -1; d->gid = -1; d->mtime = time(0); d->atime = d->mtime; d++; strcpy(d->name, "/"); d->mode = DALLOC | 0775; d->path = ROOTQID; d->type = QTDIR; d->uid = -1; d->muid = -1; d->gid = -1; d->mtime = time(0); d->atime = d->mtime; c->op |= BWRIM; putbuf(c); c = getbuf(fs->d, SUPERBLK, TSUPERBLOCK, 0); if(c == nil) goto error; fs->root = r; c->sb.root = r; c->op |= BDELWRI; putbuf(c); } void writeusers(Fs *fs) { Chan *ch; ch = chanattach(fs, 0); if(ch == nil) goto error; ch->uid = -1; chancreat(ch, "adm", DMDIR | 0775, OREAD); chanclunk(ch); ch = chanattach(fs, 0); if(ch == nil) goto error; ch->uid = -1; if(chanwalk(ch, "adm") <= 0) goto error; if(chanwalk(ch, "users") > 0){ if(chanopen(ch, OWRITE|OTRUNC) <= 0) goto error; }else if(chancreat(ch, "users", 0664, OWRITE) <= 0) goto error; if(userssave(fs, ch) < 0){ chanremove(ch); ch = nil; goto error; } chanclunk(ch); return; error: if(ch != nil) chanclunk(ch); dprint("writeusers: %r\n"); } void readusers(Fs *fs) { Chan *ch; ch = chanattach(fs, 0); if(ch == nil) goto err; ch->uid = -1; if(chanwalk(ch, "adm") <= 0) goto err; if(chanwalk(ch, "users") <= 0) goto err; if(chanopen(ch, OREAD) < 0) goto err; if(usersload(fs, ch) < 0) goto err; chanclunk(ch); return; err: if(ch != nil) chanclunk(ch); dprint("readusers: %r\nhjfs: using default user db\n"); } void ream(Fs *fs) { Dev *d; Buf *b, *c; uvlong i, firsti, lasti; int j, je; d = fs->d; dprint("reaming %s\n", d->name); b = getbuf(d, SUPERBLK, TSUPERBLOCK, 1); if(b == nil) err: sysfatal("ream: getbuf: %r"); memset(&b->sb, 0, sizeof(b->sb)); b->sb.magic = SUPERMAGIC; b->sb.size = d->size; b->sb.fstart = SUPERBLK + 1; fs->fstart = b->sb.fstart; b->sb.fend = b->sb.fstart + HOWMANY(b->sb.size * REFSIZ); b->sb.qidpath = DUMPROOTQID + 1; firsti = b->sb.fstart + SUPERBLK / REFPERBLK; lasti = b->sb.fstart + b->sb.fend / REFPERBLK; for(i = b->sb.fstart; i < b->sb.fend; i++){ c = getbuf(d, i, TREF, 1); if(c == nil) goto err; memset(c->refs, 0, sizeof(c->refs)); if(i >= firsti && i <= lasti){ j = 0; je = REFPERBLK; if(i == firsti) j = SUPERBLK % REFPERBLK; if(i == lasti) je = b->sb.fend % REFPERBLK; for(; j < je; j++) c->refs[j] = 1; } if(i == b->sb.fend - 1){ j = b->sb.size % REFPERBLK; if(j != 0) for(; j < REFPERBLK; j++) c->refs[j] = -1; } c->op |= BWRIM; putbuf(c); } b->op |= BDELWRI; putbuf(b); createroot(fs); sync(1); dprint("ream successful\n"); } Fs * initfs(Dev *d, int doream, int flags) { Fs *fs; Buf *b; FLoc f; fs = emalloc(sizeof(*fs)); fs->d = d; if(doream) ream(fs); b = getbuf(d, SUPERBLK, TSUPERBLOCK, 0); if(b == nil || b->sb.magic != SUPERMAGIC) goto error; fs->root = b->sb.root; fs->fstart = b->sb.fstart; fs->freelist = chancreate(sizeof(uvlong), FREELISTLEN); f.blk = fs->root; f.deind = 0; f.path = ROOTQID; f.vers = 0; f.type = QTDIR; fs->rootloc = getloc(fs, f, nil); f.deind++; f.path = DUMPROOTQID; fs->dumprootloc = getloc(fs, f, nil); putbuf(b); fs->flags = flags; if(doream) writeusers(fs); readusers(fs); dprint("fs is %s\n", d->name); return fs; error: if(b != nil) putbuf(b); free(fs); return nil; } void chbegin(Chan *ch) { if((ch->flags & CHFNOLOCK) == 0) rlock(ch->fs); } void chend(Chan *ch) { if((ch->flags & CHFNOLOCK) == 0) runlock(ch->fs); } int newqid(Fs *fs, uvlong *q) { Buf *b; b = getbuf(fs->d, SUPERBLK, TSUPERBLOCK, 0); if(b == nil) return -1; *q = b->sb.qidpath++; b->op |= BDELWRI; putbuf(b); return 1; } Loc * getloc(Fs *fs, FLoc f, Loc *next) { Loc *l; qlock(&fs->loctree); if(next != nil && next->child != nil){ l = next->child; do{ if(l->blk == f.blk && l->deind == f.deind){ l->ref++; qunlock(&fs->loctree); return l; } l = l->cnext; }while(l != next->child); } l = emalloc(sizeof(*l)); l->ref = 1; l->FLoc = f; l->next = next; if(fs->rootloc != nil){ l->gnext = fs->rootloc; l->gprev = l->gnext->gprev; l->gnext->gprev = l; l->gprev->gnext = l; }else l->gnext = l->gprev = l; l->cprev = l->cnext = l; if(next != nil){ if(next->child == nil) next->child = l; else{ l->cnext = next->child; l->cprev = next->child->cprev; l->cnext->cprev = l; l->cprev->cnext = l; } } qunlock(&fs->loctree); return l; } int haveloc(Fs *fs, uvlong blk, int deind, Loc *next) { Loc *l; qlock(&fs->loctree); l = next->child; if(l != nil) do{ if(l->blk == blk && l->deind == deind){ qunlock(&fs->loctree); return 1; } l = l->cnext; } while(l != next->child); qunlock(&fs->loctree); return 0; } Loc * cloneloc(Fs *fs, Loc *l) { Loc *m; qlock(&fs->loctree); for(m = l; m != nil; m = m->next) m->ref++; qunlock(&fs->loctree); return l; } void putloc(Fs *fs, Loc *l, int loop) { Loc *m; Buf *b; qlock(&fs->loctree); if(!loop && --l->ref <= 0) goto freeit; while(loop && l != nil && l->ref <= 1){ freeit: if((l->flags & LGONE) != 0){ /* * safe to unlock here, the file is gone and * we're the last reference. */ qunlock(&fs->loctree); b = getbuf(fs->d, l->blk, TDENTRY, 0); if(b != nil){ delete(fs, l, b); putbuf(b); } qlock(&fs->loctree); } l->cnext->cprev = l->cprev; l->cprev->cnext = l->cnext; l->gnext->gprev = l->gprev; l->gprev->gnext = l->gnext; if(l->next != nil && l->next->child == l){ if(l->cnext == l) l->next->child = nil; else l->next->child = l->cnext; } m = l->next; free(l); l = m; } for(; loop && l != nil; l = l->next) --l->ref; qunlock(&fs->loctree); } static int dumpblk(Fs *fs, FLoc *, uvlong *l) { uvlong n; int i; Buf *b, *c; Dentry *d; b = getbuf(fs->d, *l, TDONTCARE, 0); if(b == nil) return -1; if(getfree(fs, &n) < 0){ berr: putbuf(b); return -1; } c = getbuf(fs->d, n, b->type, 1); if(c == nil){ putfree(fs, n); goto berr; } switch(b->type){ case TINDIR: memcpy(c->offs, b->offs, sizeof(b->offs)); for(i = 0; i < OFFPERBLK; i++) if(b->offs[i] != 0) chref(fs, b->offs[i], 1); break; case TRAW: memcpy(c->data, b->data, sizeof(b->data)); break; case TDENTRY: memcpy(c->de, b->de, sizeof(b->de)); for(d = b->de; d < &b->de[DEPERBLK]; d++){ if((d->mode & DALLOC) == 0) continue; if((d->type & QTTMP) != 0) continue; for(i = 0; i < NDIRECT; i++) if(d->db[i] != 0) chref(fs, d->db[i], 1); for(i = 0; i < NINDIRECT; i++) if(d->ib[i] != 0) chref(fs, d->ib[i], 1); } break; default: werrstr("dumpblk -- unknown type %d", b->type); putfree(fs, n); putbuf(c); putbuf(b); return -1; } c->op |= BDELWRI; putbuf(c); putbuf(b); putfree(fs, *l); *l = n; return 0; } /* * getblk returns the address of a block in a file * given its relative address blk * the address are returned in *r * mode has to be one of: * - GBREAD: this block will only be read * - GBWRITE: this block will be written, but don't create it * if it doesn't exist * - GBCREATE: this block will be written, create it if necessary * - GBOVERWR: like GBCREATE, but return an empty block if a dump * would be necessary * return value is 1 if the block existed, -1 on error * a return value of 0 means the block did not exist * this is only an error in case of GBREAD and GBWRITE */ int getblk(Fs *fs, FLoc *L, Buf *bd, uvlong blk, uvlong *r, int mode) { uvlong k, l; uvlong *loc; int i, j, rc, prc; Buf *b; Dentry *d; b = bd; d = getdent(L, b); if(d == nil){ dprint("getblk: dirent gone\n"); return -1; } if(blk < NDIRECT){ loc = &d->db[blk]; goto found; } blk -= NDIRECT; l = 1; for(i = 0; i < NINDIRECT; i++){ l *= OFFPERBLK; if(blk < l) break; blk -= l; } if(i == NINDIRECT){ werrstr("getblk: block offset too large"); return -1; } loc = &d->ib[i]; for(j = 0; j <= i; j++){ if(*loc == 0){ if(mode == GBREAD || mode == GBWRITE){ if(b != bd) putbuf(b); return 0; } if(getfree(fs, loc) < 0){ if(b != bd) putbuf(b); return -1; } b->op |= BDELWRI; k = *loc; if(b != bd) putbuf(b); b = getbuf(fs->d, k, TINDIR, 1); if(b == nil) return -1; memset(b->offs, 0, sizeof(b->offs)); b->op |= BDELWRI; }else{ if(mode != GBREAD && chref(fs, *loc, 0) > 1){ if(dumpblk(fs, L, loc) < 0){ if(b != bd) putbuf(b); return -1; } b->op |= BDELWRI; } k = *loc; if(b != bd) putbuf(b); b = getbuf(fs->d, k, TINDIR, 0); if(b == nil) return -1; } l /= OFFPERBLK; loc = &b->offs[blk / l]; blk %= l; } found: rc = 0; prc = 0; if(*loc != 0){ if(mode == GBREAD) goto okay; if((rc = chref(fs, *loc, 0)) > 1){ if(mode == GBOVERWR){ putfree(fs, *loc); *loc = 0; b->op |= BDELWRI; prc = 1; goto new; } if(dumpblk(fs, L, loc) < 0){ rc = -1; goto end; } b->op |= BDELWRI; } if(rc < 0) goto end; if(rc == 0){ dprint("getblk: block %lld has refcount 0\n"); werrstr("phase error -- getblk"); rc = -1; goto end; } okay: *r = *loc; rc = 1; }else if(mode == GBCREATE || mode == GBOVERWR){ new: rc = getfree(fs, r); if(rc > 0){ *loc = *r; b->op |= BDELWRI; rc = prc; } } end: if(b != bd) putbuf(b); return rc; } static void delindir(Fs *fs, uvlong *l, int n) { Buf *b; int k; if(*l == 0) return; if(chref(fs, *l, 0) > 1){ *l = 0; return; } if(n > 0){ b = getbuf(fs->d, *l, TINDIR, 0); if(b != nil){ for(k = 0; k < OFFPERBLK; k++) if(b->offs[k] != 0){ delindir(fs, &b->offs[k], n-1); b->op |= BDELWRI; } putbuf(b); } } putfree(fs, *l); *l = 0; } static int zeroes(int *a, int i) { while(i--) if(*a++ != 0) return 0; return 1; } static void delindirpart(Fs *fs, FLoc *p, uvlong *l, int *a, int n) { Buf *b; int k; if(*l == 0) return; if(n == 0){ putfree(fs, *l); *l = 0; return; } if(zeroes(a, n)){ delindir(fs, l, n); return; } if(chref(fs, *l, 0) > 1) dumpblk(fs, p, l); b = getbuf(fs->d, *l, TINDIR, 0); if(b == nil) return; delindirpart(fs, p, &b->offs[*a], a + 1, n - 1); for(k = a[0] + 1; k < OFFPERBLK; k++) if(b->offs[k] != 0) delindir(fs, &b->offs[k], n - 1); b->op |= BDELWRI; putbuf(b); } /* * call willmodify() before and modified() * after calling this function */ int trunc(Fs *fs, FLoc *ll, Buf *bd, uvlong size) { uvlong blk; Dentry *d; int a[NINDIRECT]; uvlong l; int i, j; d = getdent(ll, bd); if(d == nil) return -1; if(size >= d->size) goto done; blk = HOWMANY(size); while(blk < NDIRECT){ if(d->db[blk] != 0){ putfree(fs, d->db[blk]); d->db[blk] = 0; bd->op |= BDELWRI; } blk++; } blk -= NDIRECT; l = 1; for(i = 0; i < NINDIRECT; i++){ l *= OFFPERBLK; if(blk < l) break; blk -= l; } if(blk >= l){ werrstr("phase error -- truncate"); return -1; } if(blk == 0) goto rest; if(d->ib[i] == 0){ i++; goto rest; } for(j = 0; j <= i; j++){ l /= OFFPERBLK; a[j] = blk / l; blk %= l; } delindirpart(fs, ll, &d->ib[i], a, i + 1); i++; rest: for(; i < NINDIRECT; i++) delindir(fs, &d->ib[i], i + 1); done: d->size = size; bd->op |= BDELWRI; return 1; } /* * find a direntry * name == nil allows any entry to match * rl == nil allowed * return value 1 on success, 0 on Enoent, * -1 on other errors */ int findentry(Fs *fs, FLoc *l, Buf *b, char *name, FLoc *rl, int dump) { uvlong i; int j; Dentry *d; uvlong r; Buf *c; d = getdent(l, b); if(d == nil) return -1; for(i = 0; i < d->size; i++){ if(getblk(fs, l, b, i, &r, GBREAD) <= 0) continue; c = getbuf(fs->d, r, TDENTRY, 0); if(c == nil) continue; for(j = 0; j < DEPERBLK; j++) if((c->de[j].mode & DALLOC) != 0 && (name == nil || strcmp(c->de[j].name, name) == 0)){ if(dump && (c->de[j].type & QTTMP) != 0) continue; if(rl != nil){ rl->Qid = c->de[j].Qid; rl->blk = r; rl->deind = j; } putbuf(c); return 1; } putbuf(c); } werrstr(Enoent); return 0; } void modified(Chan *ch, Dentry *d) { d->mtime = time(0); d->atime = d->mtime; d->muid = ch->uid; ch->loc->vers = ++d->vers; } typedef struct Del Del; struct Del { FLoc; Del *next, *prev; }; static int deltraverse(Fs *fs, Del *p, Buf *b, Del **last) { Buf *c; int frb; Dentry *d; uvlong i, s, r; int j, rc; Del *dd; frb = b == nil; if(frb){ b = getbuf(fs->d, p->blk, TDENTRY, 0); if(b == nil) return -1; } d = getdent(p, b); if(d == nil){ if(frb) putbuf(b); return -1; } s = d->size; for(i = 0; i < s; i++){ rc = getblk(fs, p, b, i, &r, GBREAD); if(rc <= 0) continue; c = getbuf(fs->d, r, TDENTRY, 0); if(c == nil) continue; for(j = 0; j < DEPERBLK; j++){ d = &c->de[j]; if((d->mode & (DALLOC|DGONE)) != 0){ if((d->type & QTDIR) == 0){ trunc(fs, p, b, 0); memset(d, 0, sizeof(*d)); c->op |= BDELWRI; }else{ dd = emalloc(sizeof(Del)); dd->blk = i; dd->deind = j; dd->Qid = d->Qid; dd->prev = *last; (*last)->next = dd; *last = dd; } } } putbuf(c); } if(frb) putbuf(b); return 0; } int delete(Fs *fs, FLoc *l, Buf *b) { Dentry *d; Buf *c; Del *first, *last, *p, *q; d = getdent(l, b); if(d == nil) return -1; if((d->type & QTDIR) == 0){ trunc(fs, l, b, 0); memset(d, 0, sizeof(*d)); b->op |= BDELWRI; return 0; } first = last = emalloc(sizeof(Del)); first->FLoc = *l; for(p = first; p != nil; p = p->next) deltraverse(fs, p, p == first ? b : nil, &last); for(p = last; p != nil; q = p->prev, free(p), p = q){ if(p == first) c = b; else c = getbuf(fs->d, p->blk, TDENTRY, 0); if(c == nil) continue; d = getdent(p, c); if(d != nil){ trunc(fs, p, c, 0); memset(d, 0, sizeof(*d)); c->op |= BDELWRI; } if(p != first) putbuf(c); } return 0; } /* * newentry() looks for a free slot in the directory * and returns FLoc pointing to the slot. if no free * slot is available a new block is allocated. if * dump == 0, then the resulting blk from the FLoc * *is not* dumped, so to finally allocate the Dentry, * one has to call willmodify() on res before modyfing it. */ int newentry(Fs *fs, Loc *l, Buf *b, char *name, FLoc *res, int dump) { Dentry *d, *dd; uvlong i, si, r; int j, sj; Buf *c; d = getdent(l, b); if(d == nil) return -1; si = sj = -1; for(i = 0; i < d->size; i++){ if(getblk(fs, l, b, i, &r, GBREAD) <= 0) continue; c = getbuf(fs->d, r, TDENTRY, 0); if(c == nil) continue; for(j = 0; j < DEPERBLK; j++){ dd = &c->de[j]; if((dd->mode & DGONE) != 0) continue; if((dd->mode & DALLOC) != 0){ if(strcmp(dd->name, name) == 0){ werrstr(Eexists); putbuf(c); return 0; } continue; } if(si != -1 || haveloc(fs, r, j, l)) continue; si = i; sj = j; } putbuf(c); } if(si == -1 && i == d->size){ if(getblk(fs, l, b, i, &r, GBCREATE) >= 0){ c = getbuf(fs->d, r, TDENTRY, 1); if(c != nil){ si = i; sj = 0; d->size = i+1; b->op |= BDELWRI; memset(c->de, 0, sizeof(c->de)); c->op |= BDELWRI; putbuf(c); } } } if(si == -1 || sj == -1){ werrstr("phase error -- create"); return -1; } if(getblk(fs, l, b, si, &res->blk, dump != 0 ? GBWRITE : GBREAD) <= 0) return -1; res->deind = sj; res->Qid = (Qid){0, 0, 0}; return 1; }