Bug 1379472 - Cache target is not always able to transition to error state
Summary: Cache target is not always able to transition to error state
Keywords:
Status: ASSIGNED
Alias: None
Product: LVM and device-mapper
Classification: Community
Component: device-mapper
Version: 2.02.165
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
: ---
Assignee: LVM Team
QA Contact: cluster-qe
URL:
Whiteboard:
Depends On:
Blocks: 1377850
TreeView+ depends on / blocked
 
Reported: 2016-09-26 21:30 UTC by Zdenek Kabelac
Modified: 2025-05-17 08:28 UTC (History)
5 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:
rule-engine: lvm-technical-solution?


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Description Zdenek Kabelac 2016-09-26 21:30:37 UTC
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:
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Actual results:


Expected results:


Additional info:


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