struct badblock *bad, *best;
unsigned char *p = buf;
- best = 0; lo = 0; hi = badblocks.n;
+ if (badblocks.n) {
+ best = 0; lo = 0; hi = badblocks.n;
#ifdef DEBUG
- clear_progress();
- printf(";; searching badblocks for %"PRIuSEC" .. %"PRIuSEC"\n",
- pos, pos + want);
+ debug_clear_progress();
+ printf(";; searching badblocks for %"PRIuSEC" .. %"PRIuSEC"\n",
+ pos, pos + want);
#endif
- while (lo < hi) {
- mid = lo + (hi - lo)/2; bad = &badblocks.v[mid];
+ while (lo < hi) {
+ mid = lo + (hi - lo)/2; bad = &badblocks.v[mid];
#ifdef DEBUG
- printf(";; try %zu (%"PRIuSEC" .. %"PRIuSEC")... ",
- mid, bad->start, bad->end);
+ printf(";; try %zu (%"PRIuSEC" .. %"PRIuSEC")... ",
+ mid, bad->start, bad->end);
#endif
- if (pos < bad->start) { D( printf("high\n"); ) best = bad; hi = mid; }
- else if (pos >= bad->end) { D( printf("low\n"); ) lo = mid + 1; }
- else { D( printf("match!\n"); ) errno = EIO; return (-1); }
- }
+ if (pos < bad->start) { D( printf("high\n"); ) best = bad; hi = mid; }
+ else if (pos >= bad->end) { D( printf("low\n"); ) lo = mid + 1; }
+ else { D( printf("match!\n"); ) errno = EIO; return (-1); }
+ }
#ifdef DEBUG
- if (best)
- printf(";; next is %"PRIuSEC" .. %"PRIuSEC"\n",
- best->start, best->end);
+ if (best)
+ printf(";; next is %"PRIuSEC" .. %"PRIuSEC"\n",
+ best->start, best->end);
#endif
- if (best && pos + want > best->start)
- { want = best->start - pos; fakeerr = EIO; }
-
+ if (best && pos + want > best->start)
+ { want = best->start - pos; fakeerr = EIO; }
+ }
done = 0;
while (want) {
if (vob)
fflush(stdout);
}
+static void recovered(secaddr bad_lo, secaddr bad_hi)
+{
+ clear_progress();
+ moan("skipping %"PRIuSEC" bad sectors (%"PRIuSEC" .. %"PRIuSEC")",
+ bad_hi - bad_lo, bad_lo, bad_hi);
+ if (mapfile) {
+ if (!mapfp) {
+ mapfp = fopen(mapfile, "w");
+ if (!mapfp)
+ bail_syserr(errno, "failed to open bad-sector map file `%s'",
+ optarg);
+ fprintf(mapfp, "## bad sector map\n\n");
+ }
+ fprintf(mapfp, "%"PRIuSEC" %"PRIuSEC"\n", bad_lo, bad_hi);
+ fflush(mapfp);
+ if (ferror(mapfp))
+ bail_syserr(errno, "error writing bad-sector map file");
+ }
+ if (lseek(outfd, (off_t)(bad_hi - bad_lo)*SECTORSZ, SEEK_CUR) < 0)
+ bail_syserr(errno, "failed to seek past bad sectors");
+ status = 1;
+}
+
+struct recoverybuf {
+ unsigned char *buf;
+ secaddr sz, pos, start, end;
+};
+
+static void rearrange_sectors(struct recoverybuf *r,
+ secaddr dest, secaddr src, secaddr len)
+{
+ assert(dest + len <= r->sz);
+ assert(src + len <= r->sz);
+ memmove(r->buf + dest*SECTORSZ, r->buf + src*SECTORSZ, len*SECTORSZ);
+}
+
+#ifdef DEBUG
+__attribute__((format(printf, 2, 3)))
+static void show_recovery_buffer_map(const struct recoverybuf *r,
+ const char *what, ...)
+{
+ va_list ap;
+
+ va_start(ap, what);
+ clear_progress();
+ printf(";; recovery buffer (");
+ vprintf(what, ap);
+ printf("): "
+ "(%"PRIuSEC") ..%"PRIuSEC".. "
+ "[%"PRIuSEC" ..%"PRIuSEC".. %"PRIuSEC"] "
+ "..%"PRIuSEC".. (%"PRIuSEC")\n",
+ r->pos, r->start,
+ r->pos + r->start, r->end - r->start, r->pos + r->end,
+ r->sz - r->end, r->pos + r->sz);
+ va_end(ap);
+ assert(r->start <= r->end);
+ assert(r->end <= r->sz);
+}
+#endif
+
+static ssize_t recovery_read_sectors(struct recoverybuf *r,
+ secaddr pos, secaddr off, secaddr want)
+{
+ ssize_t n;
+
+ assert(off <= r->sz); assert(want <= r->sz - off);
+ n = read_sectors(pos, r->buf + off*SECTORSZ, want);
+ return (n);
+}
+
+static ssize_t recovery_read(struct recoverybuf *r,
+ secaddr pos, secaddr want)
+{
+ secaddr diff, pp, nn;
+ ssize_t n;
+
+#ifdef DEBUG
+ clear_progress();
+ show_recovery_buffer_map(r, "begin(%"PRIuSEC", %"PRIuSEC")", pos, want);
+#endif
+
+ if (pos < r->pos) {
+ diff = r->pos - pos;
+ if (r->start + diff >= r->sz) {
+ r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "cleared; shift up by %"PRIuSEC"", diff);
+#endif
+ } else {
+ if (r->end + diff > r->sz) r->end = r->sz - diff;
+ rearrange_sectors(r, r->start + diff, r->start, r->end - r->start);
+ r->pos -= diff; r->start += diff; r->end += diff;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "shifted up by %"PRIuSEC"", diff);
+#endif
+ }
+ } else if (pos > r->pos + r->end) {
+ r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "cleared; beyond previous region");
+#endif
+ } else if (pos + want > r->pos + r->sz) {
+ diff = (pos + want) - (r->pos + r->sz);
+ if (r->end <= diff) {
+ r->pos = pos; r->start = r->end = 0;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "cleared; shift down by %"PRIuSEC"", diff);
+#endif
+ } else {
+ if (r->start < diff) r->start = diff;
+ rearrange_sectors(r, r->start - diff, r->start, r->end - r->start);
+ r->pos += diff; r->start -= diff; r->end -= diff;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "shifted down by %"PRIuSEC"", diff);
+#endif
+ }
+ }
+
+ if (pos < r->pos + r->start) {
+ pp = pos - r->pos; nn = r->start - pp;
+#ifdef DEBUG
+ printf(";; read low (%"PRIuSEC"@%"PRIuSEC", %"PRIuSEC")", pos, pp, nn);
+ fflush(stdout);
+#endif
+ n = recovery_read_sectors(r, pos, pp, nn);
+#ifdef DEBUG
+ printf(" -> %zd\n", n);
+#endif
+ if (n != nn) {
+ if (n >= 0 && n > want) n = want;
+ goto end;
+ }
+ r->start = pp;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "joined new region");
+#endif
+ }
+
+ if (pos + want > r->pos + r->end) {
+ pp = r->end; nn = (pos + want) - (r->pos + r->end);
+#ifdef DEBUG
+ printf(";; read high (%"PRIuSEC"@%"PRIuSEC", %"PRIuSEC")",
+ r->pos + pp, pp, nn);
+ fflush(stdout);
+#endif
+ n = recovery_read_sectors(r, pos + pp, pp, nn);
+#ifdef DEBUG
+ printf(" -> %zd\n", n);
+#endif
+ if (n > 0) {
+ r->end += n;
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "joined new region");
+#endif
+ }
+ }
+
+ n = r->pos + r->end - pos;
+ if (!n && want) n = -1;
+
+end:
+#ifdef DEBUG
+ show_recovery_buffer_map(r, "done; return %zd", n);
+#endif
+ return (n);
+}
+
+static secaddr run_length_wanted(secaddr pos, secaddr badlen,
+ secaddr sz, secaddr end)
+{
+ secaddr want;
+
+ want = 3*badlen/2;
+ if (!want) want = 1;
+ if (want > end - pos) want = end - pos;
+ if (want > sz) want = sz;
+ return (want);
+}
+
static ssize_t find_good_sector(secaddr *pos_inout, secaddr end,
unsigned char *buf, secaddr sz)
{
int i;
- secaddr pos = *pos_inout, bad_lo, bad_hi, good, step;
+ secaddr pos = *pos_inout, bad_lo, bad_hi, good, step, want;
+ struct recoverybuf r;
ssize_t n;
+ r.buf = buf; r.sz = sz; r.pos = r.start = r.end = 0;
report_bad_blocks_progress(pos, pos, errno);
+
+ want = sz; if (want > end - pos) want = end - pos;
for (i = 0; i < 4; i++) {
- n = read_sectors(pos, buf, 1);
+ n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+ clear_progress();
+ printf(";; [retry] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+ pos, pos + want, n);
+#endif
if (n > 0) {
clear_progress();
moan("sector %"PRIuSEC" read ok after retry", pos);
- bad_lo = bad_hi = pos;
- goto recovered;
+ return (n);
}
}
- bad_lo = pos; step = 1; bad_hi = pos + 1;
+ bad_lo = pos; bad_hi = pos + 1;
for (;;) {
report_bad_blocks_progress(bad_lo, bad_hi, errno);
if (bad_hi >= end) {
clear_progress();
moan("giving up on this extent");
- n = 0; goto recovered;
+ recovered(bad_lo, end); *pos_inout = end; return (0);
}
- step *= 2;
- if (step > end - bad_lo) step = end - bad_lo;
+ step = 2*(bad_hi - bad_lo); if (step > end - bad_lo) step = end - bad_lo;
pos = bad_lo + step - 1;
- n = read_sectors(pos, buf, 1);
- if (n > 0) break;
- bad_hi = pos + 1;
+ want = run_length_wanted(pos, step, sz, end);
+ n = recovery_read(&r, pos, want);
+#ifdef DEBUG
+ clear_progress();
+ printf(";; [bound] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+ pos, pos + want, n);
+#endif
+ if (n == want) break;
+ if (n < 0) n = 0;
+ bad_hi = pos + n + 1;
}
good = pos;
while (good > bad_hi) {
report_bad_blocks_progress(bad_lo, bad_hi, errno);
pos = bad_hi + (good - bad_hi)/2;
- n = read_sectors(pos, buf, 1);
- if (n > 0) good = pos;
- else bad_hi = pos + 1;
- }
-recovered:
- if (bad_hi > bad_lo) {
+ step = pos - bad_lo;
+ want = run_length_wanted(pos, step, sz, end);
+ n = recovery_read(&r, pos, want);
+#ifdef DEBUG
clear_progress();
- moan("skipping %"PRIuSEC" bad sectors (%"PRIuSEC" .. %"PRIuSEC")",
- bad_hi - bad_lo, bad_lo, bad_hi);
- if (mapfile) {
- if (!mapfp) {
- mapfp = fopen(mapfile, "w");
- if (!mapfp)
- bail_syserr(errno, "failed to open bad-sector map file `%s'",
- optarg);
- fprintf(mapfp, "## bad sector map\n\n");
- }
- fprintf(mapfp, "%"PRIuSEC" %"PRIuSEC"\n", bad_lo, bad_hi);
- fflush(mapfp);
- if (ferror(mapfp))
- bail_syserr(errno, "error writing bad-sector map file");
- }
- if (lseek(outfd, (off_t)(bad_hi - bad_lo)*SECTORSZ, SEEK_CUR) < 0)
- bail_syserr(errno, "failed to seek past bad sectors");
- status = 1;
+ printf(";; [limit] try reading %"PRIuSEC" .. %"PRIuSEC" -> %zd\n",
+ pos, pos + want, n);
+#endif
+ if (n < 0) n = 0;
+ if (n == want) good = pos;
+ else bad_hi = pos + n + 1;
+ }
+ recovered(bad_lo, bad_hi); *pos_inout = good;
+ if (good < r.pos + r.start || r.pos + r.end <= good)
+ n = 0;
+ else {
+ n = r.pos + r.end - good;
+ rearrange_sectors(&r, 0, good - r.pos, n);
}
- *pos_inout = bad_hi;
+#ifdef DEBUG
+ show_recovery_buffer_map(&r, "returning %zd good sectors at %"PRIuSEC"",
+ n, good);
+#endif
return (n);
}
~mdw / dvdrip / blobdiff