Hello, I have an embedded x86 machine with Linux 5.2.21. The system is built using OpenEmbedded. When I update the machine from a live USB (/dev/sda), I override the whole internal memory (/dev/mmcblk1), and then I get this error: fdisk: WARNING: rereading partition table failed, kernel still uses old table: Device or resource busy (I use fdisk for notifying kernel about the changes). To find out where it is mounted I run mount | grep mmc before overwriting /dev/mmcblk1, but it prints nothing. So I run dmesg | grep mmc and I see this: (... a lot of kernel prints ...) Freeing unused kernel image memory: 1000K Write protecting kernel text and read-only data: 14468k NX-protecting the kernel data: 7000k Run /init as init process EXT4-fs (mmcblk1p2): mounted filesystem with ordered data mode. Opts: (null) (... a lot of kernel prints ...) Next I modified the ext driver to print stack when mounting, and I got: Call Trace: ? ext4_calculate_overhead+0x520/0x520 mount_bdev+0x15a/0x180 ? mount_bdev+0x15a/0x180 ? ext4_nfs_get_inode+0x50/0x50 ext4_mount+0x15/0x20 ? ext4_calculate_overhead+0x520/0x520 legacy_get_tree+0x22/0x50 vfs_get_tree+0x24/0xe0 do_mount+0x5e3/0x880 ksys_mount+0xa1/0xb0 sys_mount+0x1c/0x20 do_fast_syscall_32+0x82/0x230 entry_SYSENTER_32+0x6b/0xbe but I don't see anything that makes sense to me. What causes the device to be busy? Thank you Adam -- Ing. Adam Trhoň, Software Engineer Touchless Biometric Systems s.r.o. | Palackého třída 180/44 | 61200 Brno | CZECH REPUBLIC | Mobile: +42(0) 721 565 113 | tbs-biometrics.cz