Tests with xfstests =================== The xfstests test suite has been run on the original and modified kernels -- on all cache modes available (writethrough, writeback, writearound, none).
Summary: no regressions observed; apparently one FIX achieved in the writearound cache mode (generic/371). (attached script: 'test-bcache-cache-modes.sh') Details: ------- The bcache device is made of - caching device: 1 GB partition in NVMe drive - backing device: 5 GB partition in SCSI disk ubuntu@buneary:~/xfstests-dev$ git log --oneline -1 f769a923 (HEAD -> master, origin/master, origin/HEAD) xfs: project quota ineritance flag test The comparison of the output of xfstests/check script for the 'Failures' with original (orig) and modified (test) test kernels is provided below. # grep ^Failures: xfstests.*/xfstests.*.*.log | sed 's,/, ,' | sort -k 2,2 -k 1,1 xfstests.orig xfstests.test.none.log:Failures: ext4/032 generic/484 generic/491 generic/504 generic/537 xfstests.test xfstests.test.none.log:Failures: ext4/032 generic/484 generic/491 generic/504 generic/537 xfstests.orig xfstests.test.writearound.log:Failures: ext4/032 generic/371 generic/451 generic/484 generic/491 generic/504 generic/537 xfstests.test xfstests.test.writearound.log:Failures: ext4/032 <.........> generic/451 generic/484 generic/491 generic/504 generic/537 xfstests.orig xfstests.test.writeback.log:Failures: generic/484 generic/491 generic/504 generic/537 xfstests.test xfstests.test.writeback.log:Failures: generic/484 generic/491 generic/504 generic/537 xfstests.orig xfstests.test.writethrough.log:Failures: ext4/032 generic/484 generic/491 generic/504 generic/537 xfstests.test 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: Invalid Status in linux source package in Bionic: In Progress Status in linux source package in Cosmic: In Progress 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 almost every patch 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), fio (random read-write) and iozone (several read/write tests). [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
