Hi all, It seems I’ve triggered some kind of bug (based on the log) when trying to mount a device I’m trying to access a EXT4 formatted LVM volume on a read-only PVS but as soon as I try to mount (with: -o ro,noload) I’m getting a kernel oops. The system is running Debian jessie with kernel 3.16.0-11-amd64. Any suggestions how to get around this issue (if at all)? /var/log/kern.log: Aug 7 09:37:38 xoa04-ede1 kernel: [ 793.269337] EXT4-fs (dm-2): orphan cleanup on readonly fs Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.082158] EXT4-fs error (device dm-2): ext4_read_inode_bitmap:177: comm mount: Corrupt inode bitmap - block_group = 193, inode_bitmap = 6291473 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.083736] Buffer I/O error on device dm-2, logical block 0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.084784] lost page write due to I/O error on dm-2 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.085747] EXT4-fs error (device dm-2): ext4_orphan_get:1086: comm mount: inode bitmap error for orphan 1580546 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.087649] EXT4-fs (dm-2): previous I/O error to superblock detected Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.089161] Buffer I/O error on device dm-2, logical block 0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.090846] lost page write due to I/O error on dm-2 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.092414] BUG: unable to handle kernel paging request at ffffffffffffff98 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.095168] IP: [<ffffffffa01ecbdf>] ext4_fill_super+0x32ef/0x3510 [ext4] Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] PGD 1817067 PUD 1819067 PMD 0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] Oops: 0002 [#1] SMP Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] Modules linked in: loop binfmt_misc xt_tcpudp ip6t_REJECT ip6table_filter nf_nat_ftp xt_REDIRECT xt_conntrack nf_conntrack_ftp xt_LOG xt_limit xt_multiport iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 ip6table_mangle ip6table_raw ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 nf_nat nf_conntrack ip6_tables iptable_mangle iptable_raw ipt_REJECT iptable_filter ip_tables x_tables dm_service_time scsi_dh_rdac xenfs xen_privcmd nfsd auth_rpcgss oid_registry sd_mod nfs_acl crc_t10dif crct10dif_generic nfs lockd fscache sunrpc ib_iser rdma_cm iw_cm ib_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi dm_multipath scsi_dh ppdev joydev ttm drm_kms_helper crc32_pclmul parport_pc parport drm evdev aesni_intel aes_x86_64 lrw processor gf128mul glue_helper serio_raw pcspkr thermal_sys ablk_helper cryptd button fuse autofs4 ext4 crc16 mbcache jbd2 dm_mod hid_generic usbhid hid sg sr_mod cdrom ata_generic xen_netfront xen_blkfront crct10dif_pclmul crct10dif_common uhci_hcd crc32c_intel ehci_hcd ata_piix psmouse i2c_piix4 libata i2c_core usbcore scsi_mod usb_common floppy Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] CPU: 1 PID: 2617 Comm: mount Not tainted 3.16.0-11-amd64 #1 Debian 3.16.84-1 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] Hardware name: Xen HVM domU, BIOS 4.7.6-6.5.1.xcpng 05/16/2019 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] task: ffff8800ea618980 ti: ffff8800eac70000 task.ti: ffff8800eac70000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RIP: 0010:[<ffffffffa01ecbdf>] [<ffffffffa01ecbdf>] ext4_fill_super+0x32ef/0x3510 [ext4] Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RSP: 0018:ffff8800eac73cb8 EFLAGS: 00010207 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RAX: ffff88021585b000 RBX: ffff8800ea98b000 RCX: ffff88021585b200 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RDX: ffffffffffffff98 RSI: ffff880036620e00 RDI: 0000000000000000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RBP: ffff8800d3bb2400 R08: 0000000000000082 R09: 000000000000030a Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] R10: 00000000000000d1 R11: 0000000000000309 R12: 0000000000000000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] R13: 000000000000000f R14: 0000000000000000 R15: ffff88021585b000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] FS: 00007f57224ee840(0000) GS:ffff880219020000(0000) knlGS:0000000000000000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] CR2: ffffffffffffff98 CR3: 00000000ea778000 CR4: 0000000000360670 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] Stack: Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] ffff880222fad160 ffffffff812cfdf6 ffff8802161cc3c0 0000000010010001 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] ffff8800ea98b2e0 ffff88021585b430 ffff88021585b158 ffff88021585b000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] ffff88021585b130 0000000000000fad 0000003feac73de0 0000000000000000 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] Call Trace: Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff812cfdf6>] ? string.isra.7+0x36/0xe0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffffa01e98f0>] ? ext4_calculate_overhead+0x3f0/0x3f0 [ext4] Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff8115bfd3>] ? register_shrinker+0x73/0xb0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffffa01e98f0>] ? ext4_calculate_overhead+0x3f0/0x3f0 [ext4] Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff811be3db>] ? mount_bdev+0x1ab/0x1e0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff811bec8b>] ? mount_fs+0x3b/0x1c0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff811da532>] ? vfs_kern_mount+0x62/0x110 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff811dd07a>] ? do_mount+0x22a/0xc90 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff811968d1>] ? alloc_pages_current+0x91/0x150 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff811dde03>] ? SyS_mount+0xa3/0xf0 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] [<ffffffff815412ac>] ? system_call_fast_compare_end+0x1c/0x21 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] Code: a6 fd ff 48 3d 00 f0 ff ff 49 89 c6 0f 87 e5 00 00 00 48 8b 83 10 03 00 00 49 8d 56 98 4c 89 f7 48 8b 88 00 02 00 00 48 89 51 08 <49> 89 4e 98 48 8d 88 00 02 00 00 49 89 4e a0 48 89 90 00 02 00 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RIP [<ffffffffa01ecbdf>] ext4_fill_super+0x32ef/0x3510 [ext4] Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] RSP <ffff8800eac73cb8> Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] CR2: ffffffffffffff98 Aug 7 09:37:39 xoa04-ede1 kernel: [ 794.096363] ---[ end trace d6493d5e4917bc66 ]--- I’m not entirely sure how relevant it is but the mount command is part of a procedure to access data stored on a read-only virtual disk (which is part of a backup solution) which boils down to; # vhdimount 20200714T234001Z.vhd /mnt/20200714T234001Z # losetup -P -r -f /mnt/20200714T234001Z/vhdi1 # lsblk /dev/loop0 NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT loop0 7:0 0 42G 1 loop |-loop0p1 259:0 0 243M 1 part |-loop0p2 259:1 0 1K 1 part `-loop0p5 259:2 0 41.8G 1 part In the above output the loop0p5 is the PV containing the VG group “system” which contains 2 volumes named root & swap. Please note that the procedure example just for illustration, the actual procedure in this case involves multiple .vhd each having it’s own loopback devices as the VG “system” is extended with multiple disks. With kind regards, Henk Kraal PS: I’m aware of the the age of the OS, I’m fully prepped to switch to buster but that path is blocked at this moment.
