[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

This bug was fixed in the package linux - 4.18.0-20.21 --- linux (4.18.0-20.21) cosmic; urgency=medium * CVE-2018-12126 // CVE-2018-12127 // CVE-2018-12130 - Documentation/l1tf: Fix small spelling typo - x86/cpu: Sanitize FAM6_ATOM naming - kvm: x86: Report STIBP on

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

** Attachment added: "kprobe-test.c" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1824827/+attachment/5259304/+files/kprobe-test.c -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1824827

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

Verification successful on Cosmic. Updated the test-case kernel part (attached), and repeated it 20+ times, without any process hanging. In all cases, the new function call into write_cache_pages() is observed in thread 0, between page index 2 and page index 1. [ 150.914872] mod_init():161 ::

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

This bug is awaiting verification that the kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification-needed- cosmic' to 'verification-done-cosmic'. If the problem still exists, change the tag

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

** Changed in: linux (Ubuntu Cosmic) Status: In Progress => Fix Committed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1824827 Title: tasks doing write()/fsync() hit deadlock in

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

The change introduced by the patch is evident in the kernel message log for Thread 0: between page indexes 2 and 1 there's now another function call to write_cache_pages() instead of just another iteration of the for-loop inside one call. Original kernel: [ 695.276320] Thread 0 running, TID =

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

Patch posted for SRU: [C][PATCH 0/1] Fix write()/fsync() deadlock in write_cache_pages() https://lists.ubuntu.com/archives/kernel-team/2019-April/100084.html -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu.

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

testcase, kernel part. ** Attachment added: "kprobe-test.c" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1824827/+attachment/5255994/+files/kprobe-test.c -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu.

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

testcase test kernel :: latest cosmic version + patch: $ uname -rv 4.18.0-18-generic #19+test20190415b1 SMP Mon Apr 15 15:43:20 UTC 2019 [ 169.145212] kprobe_test: loading out-of-tree module taints kernel. [ 169.149144] kprobe_test: module

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

testcase original kernel :: latest cosmic version: $ uname -rv 4.18.0-18-generic #19-Ubuntu SMP Tue Apr 2 18:13:16 UTC 2019 [ 654.491029] kprobe_test: loading out-of-tree module taints kernel. [ 654.493322] kprobe_test: module verification

[Bug 1824827] Re: tasks doing write()/fsync() hit deadlock in write_cache_pages()

testcase, userspace part. ** Attachment added: "test.c" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1824827/+attachment/5255995/+files/test.c -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu.