ext4: fix COLLAPSE RANGE test for bigalloc file systems

Blocks in collapse range should be collapsed per cluster unit when
bigalloc is enable. If bigalloc is not enable, EXT4_CLUSTER_SIZE will
be same with EXT4_BLOCK_SIZE.

With this bug fixed, patch enables COLLAPSE_RANGE for bigalloc, which
fixes a large number of xfstest failures which use fsx.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/extents.c

@@ -5404,16 +5404,13 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 	int ret;
 
 	/* Collapse range works only on fs block size aligned offsets. */
-	if (offset & (EXT4_BLOCK_SIZE(sb) - 1) ||
-	    len & (EXT4_BLOCK_SIZE(sb) - 1))
+	if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
+	    len & (EXT4_CLUSTER_SIZE(sb) - 1))
 		return -EINVAL;
 
 	if (!S_ISREG(inode->i_mode))
 		return -EINVAL;
 
-	if (EXT4_SB(inode->i_sb)->s_cluster_ratio > 1)
-		return -EOPNOTSUPP;
-
 	trace_ext4_collapse_range(inode, offset, len);
 
 	punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);