From: Mark Wooding <mdw@distorted.org.uk>
Date: Thu, 17 Feb 2022 00:16:58 +0000 (+0000)
Subject: dvd-sector-copy.c: Split bad-block recovery out into its own function.
X-Git-Url: https://git.distorted.org.uk/~mdw/dvdrip/commitdiff_plain/654a81af74e237f311c58da4ad80d280f0e37786?hp=513eba4411f9c6f8b09375734fdaafc49a962eae

dvd-sector-copy.c: Split bad-block recovery out into its own function.
---

diff --git a/dvd-sector-copy.c b/dvd-sector-copy.c
index 28a4943..f29c0d6 100644
--- a/dvd-sector-copy.c
+++ b/dvd-sector-copy.c
@@ -459,6 +459,74 @@ again:
   return (n);
 }
 
+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;
+  ssize_t n;
+
+  report_bad_blocks_progress(pos, pos, errno);
+  for (i = 0; i < 4; i++) {
+    n = read_sectors(pos, buf, 1);
+    if (n > 0) {
+      clear_progress();
+      moan("sector %"PRIuSEC" read ok after retry", pos);
+      bad_lo = bad_hi = pos;
+      goto recovered;
+    }
+  }
+
+  bad_lo = pos; step = 1; 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;
+    }
+    step *= 2;
+    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;
+  }
+
+  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) {
+    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;
+  }
+  *pos_inout = bad_hi;
+  return (n);
+}
+
 static void emit(secaddr start, secaddr end)
 {
 #define BUFSECTORS 512
@@ -466,7 +534,6 @@ static void emit(secaddr start, secaddr end)
   int least, i;
   unsigned char buf[BUFSECTORS*SECTORSZ];
   secaddr pos;
-  secaddr bad_lo, bad_hi, good, step;
   size_t want;
   ssize_t n;
   static int first_time = 1;
@@ -521,67 +588,7 @@ static void emit(secaddr start, secaddr end)
     want = end - pos; if (want > BUFSECTORS) want = BUFSECTORS;
     n = read_sectors(pos, buf, want);
 
-    if (n <= 0) {
-      report_bad_blocks_progress(pos, pos, errno);
-      for (i = 0; i < 4; i++) {
-	n = read_sectors(pos, buf, 1);
-	if (n > 0) {
-	  clear_progress();
-	  moan("sector %"PRIuSEC" read ok after retry", pos);
-	  bad_lo = bad_hi = pos;
-	  goto recovered;
-	}
-      }
-
-      bad_lo = pos; step = 1; 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;
-	}
-	step *= 2;
-	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;
-      }
-
-      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) {
-	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;
-      }
-      pos = bad_hi;
-    }
-
+    if (n <= 0) n = find_good_sector(&pos, end, buf, BUFSECTORS);
     if (n > 0) { carefully_write(outfd, buf, n*SECTORSZ); pos += n; }
     report_progress(pos); fflush(stdout);
   }