I am trying to get some traction on this bug, open for 6 months with no responses.

I have attempted to remove some variables from the equation to see what factors are potentially contributing to this kernel BUG.

First test:

I have replicated the issue on a host that does NOT run a glusterfsd, and thus only consumes a vm image from a separate server, eliminating any potential conflict from having both glusterfs server and client on the same node.

Also, the original hosts used when this bug was first reported were Supermicro Avoton Atom C2750/58. This new replication of the fault is on an older Dell PE2950 (Xeon E54xx), so the specific hardware does not seem to be a factor in the bug.

Reproduction steps:

- Fresh install of Fedora Server 22, minimal package set, with online updates.
- rpm -Uvh http://resources.ovirt.org/pub/yum-repo/ovirt-release36.rpm.
- Add this node as a new host via oVirt WebAdmin.
- Start a VM on this new node, using a disk image that resides on a glusterfs storage domain.
- Boom!


kernel-4.3.4-200.fc22.x86_64
glusterfs-fuse-3.7.6-1.fc22.x86_64
fuse-2.9.4-3.fc22.x86_64
fuse-libs-2.9.4-3.fc22.x86_64

[  316.458148] ------------[ cut here ]------------
[  316.459052] kernel BUG at mm/slub.c:3517!
[  316.459052] invalid opcode: 0000 [#1] SMP 
[  316.459052] Modules linked in: vhost_net vhost macvtap macvlan ebt_arp ebtable_nat tun nfsv3 nfs fscache fuse ebtable_filter ebtables ip6table_filter ip6_tables scsi_transport_iscsi xt_physdev br_netfilter nf_conntrack_ipv4 nf_defrag_ipv4 xt_multiport xt_conntrack dm_service_time nf_conntrack coretemp kvm_intel iTCO_wdt ipmi_ssif iTCO_vendor_support gpio_ich kvm ipmi_devintf dcdbas bnx2 lpc_ich ipmi_si i5000_edac edac_core ipmi_msghandler i5k_amb shpchp fjes acpi_cpufreq tpm_tis tpm nfsd 8021q auth_rpcgss garp mrp bridge nfs_acl lockd stp grace llc sunrpc bonding dm_multipath amdkfd amd_iommu_v2 radeon i2c_algo_bit drm_kms_helper ttm drm ata_generic serio_raw pata_acpi megaraid_sas
[  316.515263] CPU: 2 PID: 3055 Comm: qemu-system-x86 Not tainted 4.3.4-200.fc22.x86_64 #1
[  316.515263] Hardware name: Dell Inc. PowerEdge 2950/0M332H, BIOS 2.7.0 10/30/2010
[  316.515263] task: ffff88041cbbb980 ti: ffff880418e94000 task.ti: ffff880418e94000
[  316.515263] RIP: 0010:[<ffffffff81203edc>]  [<ffffffff81203edc>] kfree+0x12c/0x130
[  316.515263] RSP: 0018:ffff880418e97cc8  EFLAGS: 00010246
[  316.515263] RAX: 003ffff800000000 RBX: ffff88002a43fea0 RCX: dead000000000200
[  316.515263] RDX: 000077ff80000000 RSI: ffff88041cbbb980 RDI: ffff88002a43fea0
[  316.515263] RBP: ffff880418e97ce0 R08: ffff880418e97ca8 R09: ffffea0000a90fc0
[  316.515263] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000006e30400
[  316.515263] R13: ffffffffa054c60e R14: ffff88042b32e400 R15: ffff880418e97dc8
[  316.515263] FS:  00007f1c4e3ff700(0000) GS:ffff88043fc80000(0000) knlGS:0000000000000000
[  316.515263] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  316.515263] CR2: 0000000000000000 CR3: 0000000418c96000 CR4: 00000000000026e0
[  316.515263] Stack:
[  316.515263]  ffff88002a43fea0 0000000006e30400 ffff880418e97e60 ffff880418e97d68
[  316.515263]  ffffffffa054c60e 0000000000007c00 ffff88041c944c00 0000000280000000
[  316.515263]  0000000000007c00 0000000006e38000 0000000000000000 0000000000000000
[  316.515263] Call Trace:
[  316.515263]  [<ffffffffa054c60e>] fuse_direct_IO+0x1ee/0x310 [fuse]
[  316.515263]  [<ffffffff811a791b>] generic_file_read_iter+0x47b/0x5c0
[  316.515263]  [<ffffffffa054910c>] fuse_file_read_iter+0x4c/0x70 [fuse]
[  316.515263]  [<ffffffff81223346>] __vfs_read+0xc6/0x100
[  316.515263]  [<ffffffff81223d73>] vfs_read+0x83/0x130
[  316.515263]  [<ffffffff81224c85>] SyS_pread64+0x95/0xb0
[  316.515263]  [<ffffffff8178182e>] entry_SYSCALL_64_fastpath+0x12/0x71
[  316.515263] Code: 2a 49 8b 01 31 f6 f6 c4 40 74 04 41 8b 71 68 4c 89 cf e8 58 a2 fa ff eb a0 4c 89 d1 48 89 da 4c 89 ce e8 78 fa ff ff eb 90 0f 0b <0f> 0b 66 90 66 66 66 66 90 55 48 89 e5 41 57 41 56 41 55 41 54 
[  316.515263] RIP  [<ffffffff81203edc>] kfree+0x12c/0x130
[  316.515263]  RSP <ffff880418e97cc8>
[  316.904456] ---[ end trace a63508bc8d44e7be ]---


Second test:

Same as above, but with a fresh install of CentOS 7.2 (1511).
Result: No bug triggered. The VM runs just fine.

kernel-3.10.0-327.4.5.el7.x86_64
glusterfs-fuse-3.7.6-1.el7.x86_64
fuse-2.9.2-6.el7.x86_64
fuse-libs-2.9.2-6.el7.x86_64