fsck_msdos: Instead of bailing out when we can't reconnect a lost cluster chain, clear it.

    Also, use exit code 4 when the FS has been modified in someway.

Signed-off-by: San Mehat <san@google.com>

2 files changed, 27 insertions, 8 deletions

diff --git a/check.c b/check.c
index f6a95a0..e4a8dfa 100644
--- a/check.c
+++ b/check.c
@@ -112,6 +112,7 @@ checkfilesys(const char *fname)
 
 	mod |= readfat(dosfs, &boot, boot.ValidFat >= 0 ? boot.ValidFat : 0, &fat);
 	if (mod & FSFATAL) {
+		printf("Fatal error during readfat()\n");
 		close(dosfs);
 		return 8;
 	}
@@ -122,21 +123,27 @@ checkfilesys(const char *fname)
 
 			mod |= readfat(dosfs, &boot, i, &currentFat);
 
-			if (mod & FSFATAL)
+			if (mod & FSFATAL) {
+				printf("Fatal error during readfat() for comparison\n");
 				goto out;
+			}
 
 			mod |= comparefat(&boot, fat, currentFat, i);
 			free(currentFat);
-			if (mod & FSFATAL)
+			if (mod & FSFATAL) {
+				printf("Fatal error during FAT comparison\n");
 				goto out;
+			}
 		}
 
 	if (!quiet)
 		printf("** Phase 2 - Check Cluster Chains\n");
 
 	mod |= checkfat(&boot, fat);
-	if (mod & FSFATAL)
+	if (mod & FSFATAL) {
+		printf("Fatal error during FAT check\n");
 		goto out;
+	}
 	/* delay writing FATs */
 
 	if (!quiet)
@@ -144,8 +151,10 @@ checkfilesys(const char *fname)
 
 	mod |= resetDosDirSection(&boot, fat);
 	finish_dosdirsection = 1;
-	if (mod & FSFATAL)
+	if (mod & FSFATAL) {
+		printf("Fatal error during resetDosDirSection()\n");
 		goto out;
+	}
 	/* delay writing FATs */
 
 	mod |= handleDirTree(dosfs, &boot, fat);
@@ -163,8 +172,10 @@ checkfilesys(const char *fname)
 	if (mod & FSFATMOD) {
 		if (ask(1, "Update FATs")) {
 			mod |= writefat(dosfs, &boot, fat, mod & FSFIXFAT);
-			if (mod & FSFATAL)
+			if (mod & FSFATAL) {
+				printf("Fatal error during writefat()\n");
 				goto out;
+			}
 		} else
 			mod |= FSERROR;
 	}
@@ -205,8 +216,10 @@ checkfilesys(const char *fname)
 	free(fat);
 	close(dosfs);
 
-	if (mod & (FSFATMOD|FSDIRMOD))
+	if (mod & (FSFATMOD|FSDIRMOD)) {
 		pwarn("\n***** FILE SYSTEM WAS MODIFIED *****\n");
+		return 4; 
+	}
 
 	return ret;
 }
diff --git a/fat.c b/fat.c
index 3411196..8871407 100644
--- a/fat.c
+++ b/fat.c
@@ -667,8 +667,14 @@ checklost(int dosfs, struct bootblock *boot, struct fatEntry *fat)
 		pwarn("Lost cluster chain at cluster %u\n%d Cluster(s) lost\n",
 		      head, fat[head].length);
 		mod |= ret = reconnect(dosfs, boot, fat, head);
-		if (mod & FSFATAL)
-			break;
+		if (mod & FSFATAL) {
+			/* If the reconnect failed, then just clear the chain */
+			pwarn("Error reconnecting chain - clearing\n");
+			mod &= ~FSFATAL;
+			clearchain(boot, fat, head);
+			mod |= FSFATMOD;
+			continue;
+		}
 		if (ret == FSERROR && ask(1, "Clear")) {
 			clearchain(boot, fat, head);
 			mod |= FSFATMOD;