Turn on lwext4 debugging to see if that helps.

diff --git a/src/tools/dcpomatic_disk_writer.cc b/src/tools/dcpomatic_disk_writer.cc
index b6445ca820a9d8c87afac85e01d5bcd0b3683d8a..d22bff4128368e5a03282910cfd6c072002c4e60 100644 (file)
--- a/src/tools/dcpomatic_disk_writer.cc
+++ b/src/tools/dcpomatic_disk_writer.cc
@@ -243,7 +243,7 @@ void
 write (boost::filesystem::path dcp_path, string device)
 try
 {
 write (boost::filesystem::path dcp_path, string device)
 try
 {

-//     ext4_dmask_set (DEBUG_ALL);
+       ext4_dmask_set (DEBUG_ALL);

 
        /* We rely on static initialization for these */
        static struct ext4_fs fs;
 
        /* We rely on static initialization for these */
        static struct ext4_fs fs;


@@ -277,7 +277,6 @@ try
 
        /* XXX: not sure if disk_id matters */
        int r = ext4_mbr_write (bd, &parts, 0);
 
        /* XXX: not sure if disk_id matters */
        int r = ext4_mbr_write (bd, &parts, 0);

-

        if (r) {
                throw CopyError ("Failed to write MBR", r);
        }
        if (r) {
                throw CopyError ("Failed to write MBR", r);
        }