[PATCH v2 4/4] fsx: move range generation logic into a common helper

[fdmanana@xxxxxxxxxx]

From: Filipe Manana <fdmanana@xxxxxxxx>

We have very similar code that generates the destination range for clone,
dedupe and copy_file_range operations, so avoid duplicating the code three
times and move it into a helper function.

Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
---

V2: Turned the first parameter of the helper into a boolean as Darrick suggested.

 ltp/fsx.c | 91 +++++++++++++++++++++++++--------------------------------------
 1 file changed, 36 insertions(+), 55 deletions(-)

diff --git a/ltp/fsx.c b/ltp/fsx.c
index 89a5f60e..9bfc98e0 100644
--- a/ltp/fsx.c
+++ b/ltp/fsx.c
@@ -1930,6 +1930,36 @@ range_overlaps(
 	return llabs((unsigned long long)off1 - off0) < size;
 }
 
+static void generate_dest_range(bool readbdy_align,
+				unsigned long max_range_end,
+				unsigned long *src_offset,
+				unsigned long *size,
+				unsigned long *dst_offset)
+{
+	int tries = 0;
+
+	TRIM_OFF_LEN(*src_offset, *size, file_size);
+	if (readbdy_align) {
+		*src_offset -= *src_offset % readbdy;
+		if (o_direct)
+			*size -= *size % readbdy;
+	} else {
+		*src_offset = *src_offset & ~(block_size - 1);
+		*size = *size & ~(block_size - 1);
+	}
+
+	do {
+		if (tries++ >= 30) {
+			*size = 0;
+			break;
+		}
+		*dst_offset = random();
+		TRIM_OFF(*dst_offset, max_range_end);
+		*dst_offset = *dst_offset & ~(block_size - 1);
+	} while (range_overlaps(*src_offset, *dst_offset, *size) ||
+		 *dst_offset + *size > max_range_end);
+}
+
 int
 test(void)
 {
@@ -2004,63 +2034,14 @@ test(void)
 			keep_size = random() % 2;
 		break;
 	case OP_CLONE_RANGE:
-		{
-			int tries = 0;
-
-			TRIM_OFF_LEN(offset, size, file_size);
-			offset = offset & ~(block_size - 1);
-			size = size & ~(block_size - 1);
-			do {
-				if (tries++ >= 30) {
-					size = 0;
-					break;
-				}
-				offset2 = random();
-				TRIM_OFF(offset2, maxfilelen);
-				offset2 = offset2 & ~(block_size - 1);
-			} while (range_overlaps(offset, offset2, size) ||
-				 offset2 + size > maxfilelen);
-			break;
-		}
+		generate_dest_range(false, maxfilelen, &offset, &size, &offset2);
+		break;
 	case OP_DEDUPE_RANGE:
-		{
-			int tries = 0;
-
-			TRIM_OFF_LEN(offset, size, file_size);
-			offset = offset & ~(block_size - 1);
-			size = size & ~(block_size - 1);
-			do {
-				if (tries++ >= 30) {
-					size = 0;
-					break;
-				}
-				offset2 = random();
-				TRIM_OFF(offset2, file_size);
-				offset2 = offset2 & ~(block_size - 1);
-			} while (range_overlaps(offset, offset2, size) ||
-				 offset2 + size > file_size);
-			break;
-		}
+		generate_dest_range(false, file_size, &offset, &size, &offset2);
+		break;
 	case OP_COPY_RANGE:
-		{
-			int tries = 0;
-
-			TRIM_OFF_LEN(offset, size, file_size);
-			offset -= offset % readbdy;
-			if (o_direct)
-				size -= size % readbdy;
-			do {
-				if (tries++ >= 30) {
-					size = 0;
-					break;
-				}
-				offset2 = random();
-				TRIM_OFF(offset2, maxfilelen);
-				offset2 -= offset2 % writebdy;
-			} while (range_overlaps(offset, offset2, size) ||
-				 offset2 + size > maxfilelen);
-			break;
-		}
+		generate_dest_range(true, maxfilelen, &offset, &size, &offset2);
+		break;
 	}
 
 have_op:
-- 
2.11.0