[gnome-multi-writer/wip/hadess/more-random: 2/2] Fix gmw-probe only testing the first 15% of the disks

[Bastien Nocera <hadess src gnome org>]

commit f2466c74f2b0f0506ba01d74e06c045f08662b79
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Nov 18 18:41:46 2019 +0100

    Fix gmw-probe only testing the first 15% of the disks
    
    The code was breaking up the disk in 256 chunks, to put about a block's
    worth of data around those sections, but was only saving random data for
    the 40 first ones.
    
    Fix that by making the number of chunks a constant.
    
    Fixes: 2768316

 src/gmw-probe.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/src/gmw-probe.c b/src/gmw-probe.c
index 2571fba..2417443 100644
--- a/src/gmw-probe.c
+++ b/src/gmw-probe.c
@@ -66,6 +66,10 @@ static guint32 seed = 0;
 #define GMW_ERROR_FAILED       0
 #define GMW_ERROR_IS_FAKE      1
 
+/* The number of chunks of data to read and write to
+ * verify integrity */
+#define NUM_CHUNKS 256
+
 static guint8 *
 gmw_probe_get_random_data (guint len)
 {
@@ -176,10 +180,10 @@ gmw_probe_device_data_save (GmwProbeDevice *dev,
                            GError **error)
 {
        /* aim for roughtly the same number of chunks for all device sizes */
-       guint64 chunk_size = dev->disk_size / 256;
+       guint64 chunk_size = dev->disk_size / NUM_CHUNKS;
        g_debug ("using chunk size of %" G_GUINT64_FORMAT "MB",
                 chunk_size / ONE_MB);
-       for (guint i = 1; i < 40; i++) {
+       for (guint i = 1; i < NUM_CHUNKS; i++) {
                GmwProbeBlock *item = g_new0 (GmwProbeBlock, 1);
                item->valid = TRUE;
                item->offset = g_random_int_range (1, 0xff);