------- Comment From thiag...@br.ibm.com 2017-03-13 14:27 EDT------- Hello Canonical,
Let me provide a status update: To fix this bug it's necessary to fix several issues with lifetime of structures in the block subsystem, as well as a number of related race conditions. A number of patches need to be backported to fix these problems: The "BDI lifetime fix" v3 series?, which was already merged into Linus' tree: f44f1ab5a2dc block: Unhash block device inodes on gendisk destruction dc3b17cc8bf2 block: Use pointer to backing_dev_info from request_queue d03f6cdc1fc4 block: Dynamically allocate and refcount backing_dev_info b1d2dc5659b4 block: Make blk_get_backing_dev_info() safe without open bdev efa7c9f97e3e block: Get rid of blk_get_backing_dev_info() A couple of follow up fixes were merged for commits dc3b17cc8bf and b1d2dc5659b4: e17354961bb5 zram_drv: update for backing dev info changes a5a79d00017c block: Initialize bd_bdi on inode initialization The first 4 patches from the "block: Fix block device shutdown related races" v2 series? were also merged: 4b8c861a7c79 block: Move bdev_unhash_inode() after invalidate_partition() d06e05c026ab block: Unhash also block device inode for the whole device cccd9fb9ec96 block: Revalidate i_bdev reference in bd_aquire() 165a5e22fafb block: Move bdi_unregister() to del_gendisk() A couple of follow up fixes were also merged for commit 165a5e22fafb: b6f8fec4448a block: Allow bdi re-registration df23de55615f bdi: Fix use-after-free in wb_congested_put() Commit df23de55615f depends on the following commit: 5f478e4ea5c5 block: fix double-free in the failure path of cgwb_bdi_init() In addition to the commits mentioned above, we will also need the patches from v4 of the same series, which was posted today: https://marc.info/?l=linux-block&m=148941806220331&w=2 I have a branch with the patches that were already merged upstream backported on top of tag Ubuntu-4.4.0-65.86. Most of the commits didn't have any conflicts, and the ones that did were simple to resolve. I will attach the backported patches to this bug report when all of the patches that we need are accepted upstream. -- ? https://marc.info/?l=linux-block&m=148604743126356&w=2 ? https://marc.info/?l=linux-block&m=148769705431982&w=2 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1659111 Title: UbuntuKVM guest crashed while running I/O stress test with Ubuntu kernel 4.4.0-47-generic To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1659111/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
