SRU request submitted: https://lists.ubuntu.com/archives/kernel-team/2018-May/092684.html
** Description changed: + == SRU Justification == + With the Xenial kernel, the bug reporter states there is an NBD size + overflow with image size exceeding 1TB. + + There's an issue in kernel's NBD module which prevents some larger images to be + correctly "connected" , largely described here: + https://github.com/NetworkBlockDevice/nbd/issues/44 + + This is a regression from Trusty and was fixed in mainline as of + v4.10-rc1. + + == Fix == + ef77b515243b ("nbd: use loff_t for blocksize and nbd_set_size args") + + == Regression Potential == + Medium. A backport was needed. However, it was due to some context + diffs and the way debugfs_create_u32 was used in Xenial and how + debugfs_create_u64 was used in the patch. + + == Test Case == + A test kernel was built with this patch and tested by the original bug reporter. + The bug reporter states the test kernel resolved the bug. + + + == Original Bug Report == Release 16.04, kernel 4.4.0-124-generic There's an issue in kernel's NBD module which prevents some larger images to be correctly "connected" , largely described here: https://github.com/NetworkBlockDevice/nbd/issues/44 There is a small patch here that was accepted into mainline 4.10: https://www.spinics.net/lists/linux-block/msg07060.html This is a regression from the previous LTS 3.13 kernel. ---- Here is a small example of the faulty behaviour: # qemu-img create -f qcow2 test.img 1100G Formatting 'test.img', fmt=qcow2 size=1181116006400 cluster_size=65536 lazy_refcounts=off refcount_bits=16 # qemu-nbd -c /dev/nbd0 test.img # blockdev --getsize64 /dev/nbd0 18446743055802302464 The correct response would be 1181116006400; this breaks most tools and makes the image unusable, e.g. # fdisk -l /dev/nbd0 fdisk: cannot open /dev/nbd0: Invalid argument - --- + --- AlsaDevices: - total 0 - crw-rw---- 1 root audio 116, 1 May 21 12:51 seq - crw-rw---- 1 root audio 116, 33 May 21 12:51 timer + total 0 + crw-rw---- 1 root audio 116, 1 May 21 12:51 seq + crw-rw---- 1 root audio 116, 33 May 21 12:51 timer AplayDevices: Error: [Errno 2] No such file or directory ApportVersion: 2.20.1-0ubuntu2.17 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: DistroRelease: Ubuntu 16.04 HibernationDevice: RESUME=/dev/mapper/VolGroup00-swap_1 IwConfig: Error: [Errno 2] No such file or directory MachineType: Supermicro SYS-1028R-WTR Package: linux (not installed) PciMultimedia: - + ProcEnviron: - LANGUAGE=en_AU: - TERM=xterm - PATH=(custom, no user) - LANG=en_AU - SHELL=/bin/bash + LANGUAGE=en_AU: + TERM=xterm + PATH=(custom, no user) + LANG=en_AU + SHELL=/bin/bash ProcFB: 0 VESA VGA ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.4.0-124-generic root=/dev/mapper/VolGroup00-root ro nomodeset elevator=noop consoleblank=0 net.ifnames=0 biosdevname=0 modprobe.blacklist=igb nosplash quiet ProcVersionSignature: Ubuntu 4.4.0-124.148-generic 4.4.117 RelatedPackageVersions: - linux-restricted-modules-4.4.0-124-generic N/A - linux-backports-modules-4.4.0-124-generic N/A - linux-firmware 1.157.18 + linux-restricted-modules-4.4.0-124-generic N/A + linux-backports-modules-4.4.0-124-generic N/A + linux-firmware 1.157.18 RfKill: Error: [Errno 2] No such file or directory Tags: xenial xenial Uname: Linux 4.4.0-124-generic x86_64 UnreportableReason: The report belongs to a package that is not installed. UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: - + _MarkForUpload: False dmi.bios.date: 02/08/2018 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 3.0a dmi.board.asset.tag: Default string dmi.board.name: X10DRW-i dmi.board.vendor: Supermicro dmi.board.version: 1.10 dmi.chassis.asset.tag: Default string dmi.chassis.type: 1 dmi.chassis.vendor: Supermicro dmi.chassis.version: 0123456789 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr3.0a:bd02/08/2018:svnSupermicro:pnSYS-1028R-WTR:pvr0123456789:rvnSupermicro:rnX10DRW-i:rvr1.10:cvnSupermicro:ct1:cvr0123456789: dmi.product.name: SYS-1028R-WTR dmi.product.version: 0123456789 dmi.sys.vendor: Supermicro -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1772575 Title: Kernel 4.4 NBD size overflow with image size exceeding 1TB To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1772575/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
