Hi, Chris Murphy Thanks for report this bug.
> -----Original Message----- > From: linux-btrfs-ow...@vger.kernel.org > [mailto:linux-btrfs-ow...@vger.kernel.org] On Behalf Of Chris Murphy > Sent: Thursday, July 09, 2015 11:16 AM > To: Btrfs BTRFS > Subject: [BUG] kernel BUG at fs/btrfs/scrub.c:1956!, when scrubbing freshly > converted ext4 > > OK yet another btrfs-convert bug. This one is easier to reproduce than the > others, does not damage the file system (still mounts OK) but the oops is a > hard > panic. ssh and even the virt-manager console dies instantly, but virsh console > captured a lot of call traces and are attached to the bug report. > > Happens with 4.1 and 4.2rc1 kernels. The convert was done with btrfs-progs > 4.1. > > The reproduce steps are easy: > > 1. ext4 with a bunch of files (Fedora 22 installation) plus a ~1.5GB ISO 2. > btrfs-convert using defaults goes OK no error, btrfs check has no complaints > 3. > mount 4. btrfs scrub hard panic > > https://bugzilla.kernel.org/show_bug.cgi?id=101231 > I reproduced above bug too, with following command: mkfs.ext4 /dev/vdh btrfs-convert /dev/vdh mount /dev/vdh /mnt/tmp1 btrfs scrub start -B /dev/vdh (panic) The reason is: 1: In some case, metadata(leaf) created by btrfs-convert was split into 2 strips. 2: Then scrub bypassed part of leaf data, and left data caused panic in scrub_checksum_tree_block(). For above 1: we can get following information after some simple operation. a. mkfs.ext4 /dev/vdh btrfs-convert /dev/vdh b. btrfs-debug-tree /dev/vdh we can see following item in extent tree: item 25 key (27054080 METADATA_ITEM 0) itemoff 15083 itemsize 33 Its logical address is [27054080, 27070464) and acrossed 2 strips: [27000832, 27066368) [27066368, 27131904) Qu Wenruo <quwen...@cn.fujitsu.com> is fixing above problem. For above 2: scrub is trying to do a "bypass" in this case, but the result is "panic". I'll fix it. Thanks Zhaolei > > -- > Chris Murphy > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the > body > of a message to majord...@vger.kernel.org More majordomo info at > http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
