Description of problem: When 'running' cache over scsi device which is 'offlined' it may not always properly transition to Error/Fail state. To trigger this state: Create a cached device (i.e. via lvm2:) modprobe scsi_debug dev_size_mb=100 vgcreate vg /dev/sdXXX lvcreate -L10 vg lvcreate -H -L10 vg/lvol0 Offline scsi: echo offline >/sys/block/sdXXX/device/state dmsetup status --noflush vg-lvol0: 0 24576 cache 8 7/2048 128 0/192 0 30 0 0 0 0 0 1 writethrough 2 migration_threshold 2048 smq 0 rw - Try to read 1 byte: dd if=/dev/vg/lvol0 of=/dev/null bs=1 count=1 kernel loops on: rejecting I/O to offline device If the 'dmsetup status' is with flush - cache targets switches to Fail state. Version-Release number of selected component (if applicable): 4.7 kern How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info: