Verification with bionic-proposed of xfstests results. No regressions introduced by this bcache patchset.
The comparison between -updates and -proposed is not directly possible because -proposed introduced failures via other components in I/O path (e.g., block, ext4). This is described below, and just to make sure, the -proposed kernel has been rebuilt with the bcache patchset reverted, and test results are the same (same failures with/without the patchset; no regression). It's also been confirmed (below) that tests with a raw block device (sda) instead of bcache device (thus eliminating the bcache code) shows the new/introduced failures (ext4/035, generic/553, generic/554). (the output below does look better on a very wide screen. :-) proposed kernel: 4.15.0-55.62 (with patchset) --- xfstests.test.none.log: Failures: ext4/032 ext4/035 generic/371 ----------- generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 xfstests.test.writearound.log: Failures: ext4/032 ext4/035 ----------- generic/451 generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 xfstests.test.writeback.log: Failures: -------- ext4/035 ----------- ----------- generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 xfstests.test.writethrough.log: Failures: ext4/032 ext4/035 ----------- ----------- generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 sda-only (no bcache) Failures: ext4/032 ext4/035 generic/371 ----------- generic/484 generic/491 ----------- ----------- generic/538 ----------- generic/553 generic/554 proposed kernel (4.15.0-56 without patchset) --- $ uname -rv 4.15.0-56-generic #62+test20190730b1 SMP Tue Jul 30 18:25:01 -03 2019 xfstests.test.none.log: Failures: ext4/032 ext4/035 generic/371 ----------- generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 xfstests.test.writearound.log: Failures: ext4/032 ext4/035 ----------- generic/451 generic/484 generic/491 ----------- generic/537 ----------- generic/547 generic/553 generic/554 xfstests.test.writeback.log: Failures: -------- ext4/035 ----------- ----------- generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 xfstests.test.writethrough.log: Failures: ext4/032 ext4/035 ----------- ----------- generic/484 generic/491 ----------- generic/537 ----------- ----------- generic/553 generic/554 test kernel (4.15.0-55 with patchset) --- xfstests.test.none.log: Failures: ext4/032 -------- ----------- ----------- generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- xfstests.test.writearound.log: Failures: ext4/032 -------- ----------- generic/451 generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- xfstests.test.writeback.log: Failures: -------- -------- ----------- ----------- generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- xfstests.test.writethrough.log: Failures: ext4/032 -------- ----------- ----------- generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- orig kernel (4.15.0-55) --- xfstests.test.none.log: Failures: ext4/032 -------- ----------- ----------- generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- xfstests.test.writearound.log: Failures: ext4/032 -------- generic/371 generic/451 generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- xfstests.test.writeback.log: Failures: -------- -------- ----------- ----------- generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- xfstests.test.writethrough.log: Failures: ext4/032 -------- ----------- ----------- generic/484 generic/491 generic/504 generic/537 ----------- ----------- ----------- ----------- -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1829563 Title: bcache: risk of data loss on I/O errors in backing or caching devices Status in linux package in Ubuntu: Fix Committed Status in linux source package in Bionic: Fix Committed Status in linux source package in Cosmic: Won't Fix Status in linux source package in Disco: Fix Committed Status in linux source package in Eoan: Fix Committed Bug description: [Impact] * The bcache code in Bionic lacks several fixes to handle I/O errors in both backing devices and caching devices. * Partial or permanent errors in backing or caching devices, specially in writeback mode, can lead to data loss and/or the application is not notified about failed I/O requests. * The bcache device might remain available for I/O requests even if backing device is offline, so writes are undefined. [Test Case] * Detailed test cases/steps for the behavior of many patches with code logic changes are provided in bug comments. * The patchset has been tested for regressions on each cache mode (writethrough, writeback, writearound, none) with the xfstests test suite (on ext4) and fio (sequential + random read-write). [Regression Potential] * The patchset is relatively large and touches several areas in bcache code, however, synthetic testing of the patches has been performed, and extensive regression/stress tests were run (as mentioned in Test Case section). * Many patches in the patchset are 'Fixes' patches to other patches, and no further 'Fixes' currently exist upstream. [Other Info] * Canonical Field Eng. deploys bcache+writeback extensively (e.g., BootStack, UA cloud, except rare all-flash cases). [Original Bug Description] This is a request for a backport of the following upstream patch from 4.18: "bcache: stop bcache device when backing device is offline" https://github.com/torvalds/linux/commit/0f0709e6bfc3ce4e8e1c0e8573490c45f76cfeee Field engineering uses bcache quite extensively and it would be good to have this in the GA/bionic kernel. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1829563/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
