Skipped errors for bad free clusters before they are computed

The count of free clusters may be updated while mounting before it
has been initialized, which may lead to irrelevant error messages.
Moreover the count is not computed at all in some ntfsprogs utilities.
So set up a flags to avoid outputting irrelevant errors.

include/ntfs-3g/volume.h

@@ -117,6 +117,7 @@ typedef enum {
 	NV_HideDotFiles,	/* 1: Set hidden flag on dot files */
 	NV_Compression,		/* 1: allow compression */
 	NV_NoFixupWarn,		/* 1: Do not log fixup errors */
+	NV_FreeSpaceKnown,	/* 1: The free space is now known */
 } ntfs_volume_state_bits;
 
 #define  test_nvol_flag(nv, flag)	 test_bit(NV_##flag, (nv)->state)
@@ -155,6 +156,10 @@ typedef enum {
 #define NVolSetNoFixupWarn(nv)		  set_nvol_flag(nv, NoFixupWarn)
 #define NVolClearNoFixupWarn(nv)	clear_nvol_flag(nv, NoFixupWarn)
 
+#define NVolFreeSpaceKnown(nv)		 test_nvol_flag(nv, FreeSpaceKnown)
+#define NVolSetFreeSpaceKnown(nv)	  set_nvol_flag(nv, FreeSpaceKnown)
+#define NVolClearFreeSpaceKnown(nv)	clear_nvol_flag(nv, FreeSpaceKnown)
+
 /*
  * NTFS version 1.1 and 1.2 are used by Windows NT4.
  * NTFS version 2.x is used by Windows 2000 Beta

libntfs-3g/lcnalloc.c

@@ -368,12 +368,14 @@ runlist *ntfs_cluster_alloc(ntfs_volume *vol, VCN start_vcn, s64 count,
 			/* Allocate the bitmap bit. */
 			*byte |= bit;
 			writeback = 1;
-			if (vol->free_clusters <= 0) 
-				ntfs_log_error("Non-positive free clusters "
-					       "(%lld)!\n",
+			if (NVolFreeSpaceKnown(vol)) {
+				if (vol->free_clusters <= 0)
+					ntfs_log_error("Non-positive free"
+					       " clusters (%lld)!\n",
 						(long long)vol->free_clusters);
-			else	
-				vol->free_clusters--; 
+				else	
+					vol->free_clusters--;
+			}
 			
 			/*
 			 * Coalesce with previous run if adjacent LCNs.
@@ -602,7 +604,8 @@ int ntfs_cluster_free_from_rl(ntfs_volume *vol, runlist *rl)
 	ret = 0;
 out:
 	vol->free_clusters += nr_freed; 
-	if (vol->free_clusters > vol->nr_clusters)
+	if (NVolFreeSpaceKnown(vol)
+	    && (vol->free_clusters > vol->nr_clusters))
 		ntfs_log_error("Too many free clusters (%lld > %lld)!",
 			       (long long)vol->free_clusters, 
 			       (long long)vol->nr_clusters);

libntfs-3g/volume.c

@@ -1894,8 +1894,10 @@ int ntfs_volume_get_free_space(ntfs_volume *vol)
 
 		if (vol->free_mft_records < 0)
 			ntfs_log_perror("Failed to calculate free MFT records");
-		else
+		else {
+			NVolSetFreeSpaceKnown(vol);
 			ret = 0;
+		}
 	}
 	return (ret);
 }

src/lowntfs-3g.c

@@ -4347,8 +4347,7 @@ static int ntfs_open(const char *device)
 	if (ctx->ignore_case && ntfs_set_ignore_case(vol))
 		goto err_out;
         
-	vol->free_clusters = ntfs_attr_get_free_bits(vol->lcnbmp_na);
-	if (vol->free_clusters < 0) {
+	if (ntfs_volume_get_free_space(ctx->vol)) {
 		ntfs_log_perror("Failed to read NTFS $Bitmap");
 		goto err_out;
 	}

src/ntfs-3g.c

@@ -4056,8 +4056,7 @@ static int ntfs_open(const char *device)
 				!ctx->hide_hid_files, ctx->hide_dot_files))
 		goto err_out;
 	
-	ctx->vol->free_clusters = ntfs_attr_get_free_bits(ctx->vol->lcnbmp_na);
-	if (ctx->vol->free_clusters < 0) {
+	if (ntfs_volume_get_free_space(ctx->vol)) {
 		ntfs_log_perror("Failed to read NTFS $Bitmap");
 		goto err_out;
 	}