fs/ntfs3: Fix transform resident to nonresident for compressed files

Сorrected calculation of required space len (in clusters)
for attribute data storage in case of compression.

Fixes: be71b5c ("fs/ntfs3: Add attrib operations")
Signed-off-by: Konstantin Komarov <[email protected]>

Author: aalexandrovich

fs/ntfs3/attrib.c

@@ -231,7 +231,7 @@ int attr_make_nonresident(struct ntfs_inode *ni, struct ATTRIB *attr,
 	struct ntfs_sb_info *sbi;
 	struct ATTRIB *attr_s;
 	struct MFT_REC *rec;
-	u32 used, asize, rsize, aoff, align;
+	u32 used, asize, rsize, aoff;
 	bool is_data;
 	CLST len, alen;
 	char *next;
@@ -252,10 +252,13 @@ int attr_make_nonresident(struct ntfs_inode *ni, struct ATTRIB *attr,
 	rsize = le32_to_cpu(attr->res.data_size);
 	is_data = attr->type == ATTR_DATA && !attr->name_len;
 
-	align = sbi->cluster_size;
-	if (is_attr_compressed(attr))
-		align <<= NTFS_LZNT_CUNIT;
-	len = (rsize + align - 1) >> sbi->cluster_bits;
+	/* len - how many clusters required to store 'rsize' bytes */
+	if (is_attr_compressed(attr)) {
+		u8 shift = sbi->cluster_bits + NTFS_LZNT_CUNIT;
+		len = ((rsize + (1u << shift) - 1) >> shift) << NTFS_LZNT_CUNIT;
+	} else {
+		len = bytes_to_cluster(sbi, rsize);
+	}
 
 	run_init(run);