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- #include <u.h>
- #include <libc.h>
- #include <auth.h>
- #include <fcall.h>
- #include <thread.h>
- #include <9p.h>
- #include "flashfs.h"
- enum
- {
- debug = 0,
- diags = 1,
- };
- typedef struct Gen Gen;
- typedef struct Sect Sect;
- struct Gen
- {
- int gnum;
- int count;
- int low;
- int high;
- Sect* head;
- Sect* tail;
- Sect* dup;
- Sect** vect;
- };
- struct Sect
- {
- int sect;
- ulong seq;
- int coff;
- int toff;
- int sum;
- ulong time;
- Sect* next;
- };
- static Gen gens[2];
- static Sect* freehead;
- static Sect* freetail;
- static int nfree;
- static int nbad;
- static ulong ltime;
- static int cursect;
- /*
- * If we have a delta then file times are in the future.
- * But they drift back to reality.
- */
- ulong
- now(void)
- {
- ulong cur, drift;
- static ulong last;
- cur = time(0);
- if(cur < last)
- delta += last - cur;
- else if(delta != 0 && last != 0) {
- drift = (cur - last + 1) / 2;
- if(drift > delta)
- delta = 0;
- else
- delta -= drift;
- }
- last = cur;
- return cur + delta;
- }
- static void
- damaged(char *mesg)
- {
- sysfatal("damaged filesystem: %s\n", mesg);
- }
- static void
- lddisc(char *mesg)
- {
- if(debug)
- fprint(2, "discard %s\n", mesg);
- }
- static Sect *
- getsect(void)
- {
- Sect *t;
- t = freehead;
- freehead = t->next;
- if(freehead == nil)
- freetail = nil;
- nfree--;
- return t;
- }
- static void
- newsect(Gen *g, Sect *s)
- {
- int m, n, err;
- uchar hdr[2*3];
- if(debug)
- fprint(2, "new %d %ld\n", g->gnum, s->seq);
- if(g->tail == nil)
- g->head = s;
- else
- g->tail->next = s;
- g->tail = s;
- s->next = nil;
- m = putc3(&hdr[0], g->gnum);
- n = putc3(&hdr[m], s->seq);
- s->toff = MAGSIZE + m + n;
- s->coff = s->toff + 4;
- s->time = NOTIME;
- s->sum = 0;
- err = 1;
- for(;;) {
- if(writedata(err, s->sect, hdr, m + n, MAGSIZE)
- && writedata(err, s->sect, magic, MAGSIZE, 0))
- break;
- clearsect(s->sect);
- err = 0;
- }
- }
- static Sect *
- newsum(Gen *g, ulong seq)
- {
- Sect *t;
- if(nfree == 0)
- damaged("no free sector for summary");
- t = getsect();
- t->seq = seq;
- newsect(g, t);
- return t;
- }
- static void
- freesect(Sect *s)
- {
- clearsect(s->sect);
- if(freetail == nil)
- freehead = s;
- else
- freetail->next = s;
- freetail = s;
- s->next = nil;
- nfree++;
- }
- static void
- dupsect(Sect *s, int renum)
- {
- Sect *t;
- Renum r;
- uchar *b;
- int err, n;
- ulong doff, off;
- if(nfree == 0)
- damaged("no free for copy");
- t = getsect();
- b = sectbuff;
- off = s->coff;
- readdata(s->sect, b, off, 0);
- doff = s->toff;
- if(s->time == NOTIME)
- doff += 4;
- // Window 5
- err = 1;
- for(;;) {
- if(writedata(err, t->sect, b + 1, s->toff - 1, 1)
- && writedata(err, t->sect, b + doff, off - doff, doff)
- && writedata(err, t->sect, b, 1, 0))
- break;
- clearsect(t->sect);
- err = 0;
- }
- if(renum) {
- r.old = s->sect;
- r.new = t->sect;
- erenum(&r);
- }
- n = s->sect;
- s->sect = t->sect;
- t->sect = n;
- freesect(t);
- if(cursect >= 0)
- readdata(cursect, b, sectsize, 0);
- }
- static void
- gswap(void)
- {
- Gen t;
- t = gens[0];
- gens[0] = gens[1];
- gens[1] = t;
- }
- static void
- checkdata(void)
- {
- Gen *g;
- g = &gens[0];
- if(g->dup != nil) { // Window 5 damage
- if(diags)
- fprint(2, "%s: window 5 damage\n", argv0);
- freesect(g->dup);
- g->dup = nil;
- }
- }
- static void
- checksweep(void)
- {
- Gen *g;
- Jrec j;
- uchar *b;
- int n, op;
- Sect *s, *t, *u;
- long off, seq, soff;
- g = &gens[1];
- if(g->dup != nil) { // Window 5 damage
- if(diags)
- fprint(2, "%s: window 5 damage\n", argv0);
- freesect(g->dup);
- g->dup = nil;
- }
- s = g->head;
- if(s != g->tail) {
- while(s->next != g->tail)
- s = s->next;
- }
- b = sectbuff;
- op = -1;
- seq = -1;
- soff = 0;
- u = nil;
- t = s;
- for(;;) {
- readdata(t->sect, b, sectsize, 0);
- off = t->toff + 4;
- for(;;) {
- n = convM2J(&j, &b[off]);
- if(n < 0) {
- if(j.type != 0xFF) {
- if(debug)
- fprint(2, "s[%d] @ %d %ld\n", j.type, t->sect, off);
- damaged("bad Jrec");
- }
- break;
- }
- switch(j.type) {
- case FT_SUMMARY:
- case FT_SUMBEG:
- seq = j.seq;
- case FT_SUMEND:
- op = j.type;
- soff = off;
- u = t;
- break;
- case FT_WRITE:
- case FT_AWRITE:
- off += j.size;
- }
- off += n;
- }
- t = t->next;
- if(t == nil)
- break;
- }
- if(op == FT_SUMBEG) { // Window 1 damage
- if(diags)
- fprint(2, "%s: window 1 damage\n", argv0);
- if(u != s) {
- freesect(u);
- s->next = nil;
- g->tail = s;
- }
- s->coff = soff;
- dupsect(s, 0);
- seq--;
- }
- if(seq >= 0) {
- g = &gens[0];
- if(seq > g->low)
- damaged("high sweep");
- if(seq == g->low) { // Window 2 damage
- if(diags)
- fprint(2, "%s: window 2 damage\n", argv0);
- s = g->head;
- g->head = s->next;
- freesect(s);
- if(g->head == nil) {
- g->tail = nil;
- g->gnum += 2;
- newsum(g, 0);
- gswap();
- }
- }
- }
- }
- void
- load1(Sect *s, int parity)
- {
- int n;
- Jrec j;
- uchar *b;
- char *err;
- Extent *x;
- Entry *d, *e;
- ulong ctime, off, mtime;
- if(s->sect < 0 && readonly) // readonly damaged
- return;
- b = sectbuff;
- readdata(s->sect, b, sectsize, 0);
- s->sum = 0;
- off = s->toff;
- ctime = get4(&b[off]);
- off += 4;
- for(;;) {
- n = convM2J(&j, &b[off]);
- if(n < 0) {
- if(j.type != 0xFF) {
- if(debug)
- fprint(2, "l[%d] @ %d %ld\n", j.type, s->sect, off);
- damaged("bad Jrec");
- }
- s->coff = off;
- break;
- }
- off += n;
- if(debug)
- fprint(2, "get %J\n", &j);
- switch(j.type) {
- case FT_create:
- ctime += j.mtime;
- create:
- d = elookup(j.parent);
- if(d == nil) {
- lddisc("parent");
- break;
- }
- d->ref++;
- e = ecreate(d, j.name, j.fnum, j.mode, ctime, &err);
- if(e == nil) {
- d->ref--;
- lddisc("create");
- break;
- }
- e->ref--;
- if(j.type == FT_trunc)
- e->mode = j.mode;
- break;
- case FT_chmod:
- e = elookup(j.fnum);
- if(e == nil) {
- lddisc("lookup");
- break;
- }
- echmod(e, j.mode, j.mnum);
- break;
- case FT_REMOVE:
- e = elookup(j.fnum);
- if(e == nil) {
- lddisc("lookup");
- break;
- }
- if(eremove(e) != nil) {
- lddisc("remove");
- break;
- }
- break;
- case FT_AWRITE:
- mtime = 0;
- goto write;
- case FT_WRITE:
- ctime += j.mtime;
- mtime = ctime;
- write:
- x = emalloc9p(sizeof(Extent));
- x->sect = s->sect;
- x->addr = off;
- x->off = j.offset;
- x->size = j.size;
- off += j.size;
- e = elookup(j.fnum);
- if(e == nil) {
- lddisc("lookup");
- break;
- }
- ewrite(e, x, parity, mtime);
- break;
- case FT_trunc:
- ctime += j.mtime;
- e = elookup(j.tnum);
- if(e == nil) {
- if(debug)
- fprint(2, "-> create\n");
- goto create;
- }
- etrunc(e, j.fnum, ctime);
- break;
- case FT_SUMMARY:
- case FT_SUMBEG:
- case FT_SUMEND:
- s->sum += n;
- break;
- default:
- damaged("load1 botch");
- }
- }
- if(s->sum > Nsum)
- s->sum = Nsum;
- s->time = ctime;
- if(ctime != NOTIME && ctime > ltime)
- ltime = ctime;
- }
- void
- load0(int parity)
- {
- Sect *s;
- if(debug)
- fprint(2, "load %d\n", parity);
- for(s = gens[parity].head; s != nil; s = s->next)
- load1(s, parity);
- }
- void
- loadfs(int ro)
- {
- Gen *g;
- Sect *s;
- ulong u, v;
- int i, j, n;
- uchar hdr[MAXHDR];
- readonly = ro;
- fmtinstall('J', Jconv);
- for(i = 0; i < 2; i++) {
- g = &gens[i];
- g->gnum = -1;
- g->low = nsects;
- g->high = -1;
- g->count = 0;
- g->head = nil;
- g->tail = nil;
- }
- for(i = 0; i < nsects; i++) {
- readdata(i, hdr, MAXHDR, 0);
- if(memcmp(hdr, magic, MAGSIZE) == 0) {
- n = MAGSIZE + getc3(&hdr[MAGSIZE], &u);
- getc3(&hdr[n], &v);
- if(debug)
- fprint(2, "%d: %ld %ld\n", i, u, v);
- for(j = 0; j < 2; j++) {
- g = &gens[j];
- if(g->gnum == u) {
- g->count++;
- if(v < g->low)
- g->low = v;
- if(v > g->high)
- g->high = v;
- break;
- }
- else if(g->gnum < 0) {
- g->gnum = u;
- g->count = 1;
- g->low = v;
- g->high = v;
- break;
- }
- }
- if(j == 2)
- damaged("unexpected generation");
- }
- else if(hdr[0] == 0xFF) {
- nfree++;
- s = emalloc9p(sizeof(Sect));
- s->sect = i;
- s->next = freehead;
- freehead = s;
- if(freetail == nil)
- freetail = s;
- }
- else
- nbad++;
- }
- if(nbad > 0)
- damaged("bad sectors");
- if(gens[0].gnum < 0)
- damaged("no data");
- if(gens[1].gnum < 0) { // Window 3 death
- if(diags)
- fprint(2, "%s: window 3 damage\n", argv0);
- g = &gens[1];
- g->gnum = gens[0].gnum + 1;
- g->low = 0;
- g->high = 0;
- g->count = 1;
- if(!readonly)
- newsum(g, 0);
- }
- if(gens[0].gnum > gens[1].gnum)
- gswap();
- for(i = 0; i < 2; i++) {
- g = &gens[i];
- n = g->count;
- if(n <= g->high - g->low)
- damaged("missing sectors");
- g->vect = emalloc9p(n * sizeof(Sect *));
- for(j = 0; j < n; j++) {
- s = emalloc9p(sizeof(Sect));
- s->sect = -1;
- g->vect[j] = s;
- }
- }
- if(debug) {
- for(j = 0; j < 2; j++) {
- g = &gens[j];
- print("%d\t%d\t%d-%d\n", g->gnum, g->count, g->low, g->high);
- }
- }
- for(i = 0; i < nsects; i++) {
- readdata(i, hdr, MAXHDR, 0);
- if(memcmp(hdr, magic, MAGSIZE) == 0) {
- n = MAGSIZE + getc3(&hdr[MAGSIZE], &u);
- n += getc3(&hdr[n], &v);
- g = nil;
- for(j = 0; j < 2; j++) {
- g = &gens[j];
- if(g->gnum == u)
- break;
- }
- if(j == 2)
- damaged("generation botch");
- s = g->vect[v - g->low];
- s->seq = v;
- s->toff = n;
- if(s->sect < 0)
- s->sect = i;
- else if(v == g->high && g->dup == nil) {
- s = emalloc9p(sizeof(Sect));
- s->sect = i;
- g->dup = s;
- }
- else
- damaged("dup block");
- }
- }
- for(j = 0; j < 2; j++) {
- g = &gens[j];
- for(i = 0; i < g->count; i++) {
- s = g->vect[i];
- if(g->tail == nil)
- g->head = s;
- else
- g->tail->next = s;
- g->tail = s;
- s->next = nil;
- }
- free(g->vect);
- }
- cursect = -1;
- if(!readonly) {
- checkdata();
- checksweep();
- }
- load0(1);
- load0(0);
- if(ltime != 0) {
- u = now();
- if(u < ltime) {
- delta = ltime - u;
- if(diags)
- fprint(2, "%s: check clock: delta = %lud\n", argv0, delta);
- }
- }
- limit = 80 * nsects * sectsize / 100;
- maxwrite = sectsize - MAXHDR - Nwrite - Nsum;
- if(maxwrite > WRSIZE)
- maxwrite = WRSIZE;
- }
- static int
- sputw(Sect *s, Jrec *j, int mtime, Extent *x, void *a)
- {
- ulong t;
- int err, n, r;
- uchar buff[Nmax], type[1];
- if(debug)
- fprint(2, "put %J\n", j);
- if(mtime) {
- t = j->mtime;
- if(s->time == NOTIME) {
- put4(buff, t);
- if(!writedata(1, s->sect, buff, 4, s->toff)) {
- dupsect(s, 1);
- writedata(0, s->sect, buff, 4, s->toff);
- }
- s->time = t;
- j->mtime = 0;
- }
- else {
- j->mtime = t - s->time;
- s->time = t;
- }
- }
- n = convJ2M(j, buff);
- if(n < 0)
- damaged("convJ2M");
- // Window 4
- err = 2;
- for(;;) {
- err--;
- if(!err)
- dupsect(s, 1); // Window 4 damage
- t = s->coff + 1;
- if(!writedata(err, s->sect, buff, n, t))
- continue;
- t += n;
- r = n;
- if(x != nil) {
- x->sect = s->sect;
- x->addr = t;
- if(!writedata(err, s->sect, a, j->size, t))
- continue;
- t += j->size;
- r += j->size;
- }
- type[0] = j->type;
- if(!writedata(err, s->sect, type, 1, s->coff))
- continue;
- r++;
- break;
- }
- s->coff = t;
- return r;
- }
- static void
- summarize(void)
- {
- Gen *g;
- uchar *b;
- Entry *e;
- Extent *x;
- Jrec j, sum;
- Sect *s, *t;
- ulong off, ctime;
- int n, bytes, more, mtime, sumd;
- g = &gens[eparity];
- s = g->head;
- g->head = s->next;
- if(g->head == nil)
- g->tail = nil;
- g = &gens[eparity^1];
- t = g->tail;
- b = sectbuff;
- x = nil;
- if(debug)
- fprint(2, "summarize\n");
- for(;;) { // Window 1
- readdata(s->sect, b, sectsize, 0);
- off = s->toff;
- ctime = get4(&b[off]);
- off += 4;
- sumd = 0;
- cursect = s->sect;
- while(b[off] != 0xFF) {
- n = convM2J(&j, &b[off]);
- if(n < 0)
- damaged("bad Jrec");
- if(debug)
- fprint(2, "read %J\n", &j);
- off += n;
- bytes = n;
- mtime = 0;
- switch(j.type) {
- case FT_create:
- ctime += j.mtime;
- mtime = 1;
- create:
- e = elookup(j.fnum);
- if(e == nil)
- continue;
- break;
- case FT_chmod:
- e = elookup(j.fnum);
- if(e == nil || j.mnum != e->mnum)
- continue;
- break;
- case FT_REMOVE:
- e = elookup(j.fnum);
- if(e == nil)
- continue;
- break;
- case FT_trunc:
- ctime += j.mtime;
- mtime = 1;
- e = elookup(j.tnum);
- if(e == nil) {
- if(debug)
- fprint(2, "-> create\n");
- j.type = FT_create;
- goto create;
- }
- break;
- case FT_AWRITE:
- goto write;
- case FT_WRITE:
- ctime += j.mtime;
- mtime = 1;
- write:
- e = elookup(j.fnum);
- if(e == nil) {
- off += j.size;
- continue;
- }
- x = esum(e, s->sect, off, &more);
- if(x == nil) {
- damaged("missing extent");
- off += j.size;
- continue;
- }
- if(more) {
- j.type = FT_AWRITE;
- mtime = 0;
- }
- bytes += j.size;
- break;
- case FT_SUMMARY:
- case FT_SUMBEG:
- case FT_SUMEND:
- continue;
- default:
- damaged("summarize botch");
- }
- if(!sumd) {
- if(t->coff + Nsumbeg >= sectsize - 1)
- t = newsum(g, t->seq + 1);
- sum.type = FT_SUMBEG;
- sum.seq = s->seq;
- if(debug)
- fprint(2, "+ %J\n", &sum);
- t->sum += sputw(t, &sum, 0, nil, nil);
- if(t->sum >= Nsum)
- t->sum = Nsum;
- sumd = 1;
- }
- if(t->coff + bytes >= sectsize - Nsum + t->sum - 1)
- t = newsum(g, t->seq + 1);
- if(mtime)
- j.mtime = ctime;
- switch(j.type) {
- case FT_AWRITE:
- case FT_WRITE:
- sputw(t, &j, mtime, x, &b[off]);
- off += j.size;
- break;
- default:
- sputw(t, &j, mtime, nil, nil);
- }
- }
- cursect = -1;
- if(t->coff + Nsumbeg >= sectsize - 1)
- t = newsum(g, t->seq + 1);
- if(sumd)
- sum.type = FT_SUMEND;
- else {
- sum.type = FT_SUMMARY;
- sum.seq = s->seq;
- }
- if(debug)
- fprint(2, "+ %J\n", &sum);
- t->sum += sputw(t, &sum, 0, nil, nil);
- if(t->sum >= Nsum)
- t->sum = Nsum;
- // Window 2
- freesect(s);
- g = &gens[eparity];
- s = g->head;
- if(s == nil) {
- // Window 3
- g->gnum += 2;
- newsum(g, 0);
- eparity ^= 1;
- return;
- }
- if(nfree >= Nfree)
- return;
- g->head = s->next;
- if(g->head == nil)
- g->tail = nil;
- g = &gens[eparity^1];
- }
- }
- char *
- need(int bytes)
- {
- Gen *g;
- int sums;
- Sect *s, *t;
- sums = 0;
- for(;;) {
- s = gens[eparity].tail;
- if(s->coff + bytes < sectsize - Nsum + s->sum - 1)
- return nil;
- if(nfree >= Nfree)
- break;
- if(sums == 2) {
- readonly = 1;
- return "generation full";
- }
- summarize();
- sums++;
- }
- g = &gens[eparity];
- t = getsect();
- t->seq = g->tail->seq + 1;
- newsect(g, t);
- return nil;
- }
- void
- putw(Jrec *j, int mtime, Extent *x, void *a)
- {
- sputw(gens[eparity].tail, j, mtime, x, a);
- }
- void
- put(Jrec *j, int mtime)
- {
- sputw(gens[eparity].tail, j, mtime, nil, nil);
- }
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