+ if (n > 0) { done += n; pos += n; p += n*SECTORSZ; want -= n; }
+ else if (!n || errno != EINTR) break;
+ }
+ if (fakeerr && !errno) errno = fakeerr;
+ return (!done && errno ? -1 : done);
+}
+
+static void report_bad_blocks_progress(secaddr lo, secaddr hi, int err)
+{
+ report_progress(hi);
+
+ if (lo == hi) append_progress(": retrying bad sector");
+ else
+ append_progress(": %"PRIuSEC" bad %s",
+ hi - lo, hi == lo + 1 ? "sector" : "sectors");
+ if (err && err != EIO) append_progress(" (%s)", strerror(err));
+ 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 + want <= r->sz);
+ 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