fs/ntfs3: Add functions to modify LE bitmaps

__bitmap_set/__bitmap_clear only works with bitmaps in CPU order.
Define a variant of these functions in ntfs3 to handle modifying bitmaps
read from the filesystem.
Signed-off-by: Thomas Kühnel <thomas.kuehnel@avm.de>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>

fs/ntfs3/bitmap.c

@@ -736,7 +736,7 @@ int wnd_set_free(struct wnd_bitmap *wnd, size_t bit, size_t bits)
 
 		lock_buffer(bh);
 
-		__bitmap_clear(buf, wbit, op);
+		ntfs_bitmap_clear_le(buf, wbit, op);
 
 		wnd->free_bits[iw] += op;
 
@@ -788,7 +788,7 @@ int wnd_set_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
 
 		lock_buffer(bh);
 
-		__bitmap_set(buf, wbit, op);
+		ntfs_bitmap_set_le(buf, wbit, op);
 		wnd->free_bits[iw] -= op;
 
 		set_buffer_uptodate(bh);
@@ -1363,7 +1363,7 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits)
 		lock_buffer(bh);
 		buf = (ulong *)bh->b_data;
 
-		__bitmap_clear(buf, b0, blocksize * 8 - b0);
+		ntfs_bitmap_clear_le(buf, b0, blocksize * 8 - b0);
 		frb = wbits - __bitmap_weight(buf, wbits);
 		wnd->total_zeroes += frb - wnd->free_bits[iw];
 		wnd->free_bits[iw] = frb;
@@ -1481,3 +1481,43 @@ int ntfs_trim_fs(struct ntfs_sb_info *sbi, struct fstrim_range *range)
 
 	return err;
 }
+
+void ntfs_bitmap_set_le(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_set = cpu_to_le32(BITMAP_FIRST_WORD_MASK(start));
+
+	while (len - bits_to_set >= 0) {
+		*p |= mask_to_set;
+		len -= bits_to_set;
+		bits_to_set = BITS_PER_LONG;
+		mask_to_set = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_set &= cpu_to_le32(BITMAP_LAST_WORD_MASK(size));
+		*p |= mask_to_set;
+	}
+}
+
+void ntfs_bitmap_clear_le(unsigned long *map, unsigned int start, int len)
+{
+	unsigned long *p = map + BIT_WORD(start);
+	const unsigned int size = start + len;
+	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
+	unsigned long mask_to_clear = cpu_to_le32(BITMAP_FIRST_WORD_MASK(start));
+
+	while (len - bits_to_clear >= 0) {
+		*p &= ~mask_to_clear;
+		len -= bits_to_clear;
+		bits_to_clear = BITS_PER_LONG;
+		mask_to_clear = ~0UL;
+		p++;
+	}
+	if (len) {
+		mask_to_clear &= cpu_to_le32(BITMAP_LAST_WORD_MASK(size));
+		*p &= ~mask_to_clear;
+	}
+}

fs/ntfs3/fslog.c

@@ -3624,7 +3624,7 @@ static int do_action(struct ntfs_log *log, struct OPEN_ATTR_ENRTY *oe,
 			goto dirty_vol;
 		}
 
-		__bitmap_set(Add2Ptr(buffer_le, roff), off, bits);
+		ntfs_bitmap_set_le(Add2Ptr(buffer_le, roff), off, bits);
 		a_dirty = true;
 		break;
 
@@ -3637,7 +3637,7 @@ static int do_action(struct ntfs_log *log, struct OPEN_ATTR_ENRTY *oe,
 			goto dirty_vol;
 		}
 
-		__bitmap_clear(Add2Ptr(buffer_le, roff), off, bits);
+		ntfs_bitmap_clear_le(Add2Ptr(buffer_le, roff), off, bits);
 		a_dirty = true;
 		break;
 

fs/ntfs3/ntfs_fs.h

@@ -839,6 +839,9 @@ int wnd_extend(struct wnd_bitmap *wnd, size_t new_bits);
 void wnd_zone_set(struct wnd_bitmap *wnd, size_t Lcn, size_t Len);
 int ntfs_trim_fs(struct ntfs_sb_info *sbi, struct fstrim_range *range);
 
+void ntfs_bitmap_set_le(unsigned long *map, unsigned int start, int len);
+void ntfs_bitmap_clear_le(unsigned long *map, unsigned int start, int len);
+
 /* Globals from upcase.c */
 int ntfs_cmp_names(const __le16 *s1, size_t l1, const __le16 *s2, size_t l2,
 		   const u16 *upcase, bool bothcase);