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<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">Hello,</p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">we have a bug on any xen kernel > 3.4 like this:</p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"> kernel BUG at /home/abuild/rpmbuild/BUILD/kernel-xen-3.7.9/linux-3.7/fs/buffer.c:2952!</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054552] invalid opcode: 0000 [#1] SMP </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054557] Modules linked in: bridge stp llc iptable_filter ip_tables x_tables nbd blktap2 pciback usbbk xen_scsibk openvswitch blkbk blkback_pagemap netbk xenbus_be gntdev evtchn ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm bonding af_packet edd ocfs2 ocfs2_nodemanager configfs ocfs2_stackglue quota_tree coretemp domctl crc32c_intel ghash_clmulni_intel joydev iTCO_wdt aesni_intel iTCO_vendor_support ablk_helper cryptd lrw aes_x86_64 hid_generic gpio_ich xts gf128mul 8250_core pcspkr serio_raw igb ixgbe lpc_ich mfd_core i2c_i801 serial_core usbhid sg i7core_edac ioatdma ptp pps_core edac_core hid mdio ses enclosure button uhci_hcd mgag200 ttm drm_kms_helper drm i2c_algo_bit sysimgblt sysfillrect i2c_core syscopyarea ehci_hcd usbcore usb_common processor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc scsi_dh_rdac scsi_dh xenblk cdrom xennet ata_generic ata_piix megaraid_sas</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054664] CPU 2 </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054669] Pid: 5601, comm: mc Not tainted 3.7.9-27-xen #1 Supermicro X8DTN+-F/X8DTN+-F</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054674] RIP: e030:[<ffffffff801646da>] [<ffffffff801646da>] submit_bh+0x14a/0x1d0</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054686] RSP: e02b:ffff8800ed483c88 EFLAGS: 00010246</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054690] RAX: 4000000001000004 RBX: ffff8800fd3d8260 RCX: 00000003ffffffff</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054694] RDX: 0000000000000001 RSI: ffff8800fd3d8260 RDI: 0000000000000000</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054698] RBP: ffff8800fd3d8260 R08: 0000000000000000 R09: ffffffffa04c3420</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054702] R10: 00000000000009e7 R11: 0000000000000000 R12: 00000003ffffffff</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054705] R13: 4000000000000001 R14: 4000000000000001 R15: ffff8800fd3d8260</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054715] FS: 00007f1a9c764700(0000) GS:ffff8800fbd00000(0000) knlGS:0000000000000000</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054719] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054722] CR2: 00007f1a9e199000 CR3: 00000000f340b000 CR4: 0000000000002660</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054727] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054733] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054738] Process mc (pid: 5601, threadinfo ffff8800ed482000, task ffff8800f346a040)</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054742] Stack:</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054744] 0000000000000001 ffff8800fd3d8260 0000000000000001 00000003ffffffff</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054751] 4000000000000001 ffffffffa04a5d62 ffff8800f346a040 ffffffff808e5a00</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054758] 0000001000000000 0000000000000000 0000000000000000 ffff8800d7e6bc90</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054765] Call Trace:</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054799] [<ffffffffa04a5d62>] ocfs2_read_blocks+0x1a2/0x690 [ocfs2]</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054847] [<ffffffffa04c66d4>] ocfs2_read_inode_block_full+0x34/0x60 [ocfs2]</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.054909] [<ffffffffa051382f>] ocfs2_fast_symlink_readpage+0x2f/0x170 [ocfs2]</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055006] [<ffffffff800e6df6>] do_read_cache_page+0x86/0x180</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055015] [<ffffffff800e6f49>] read_cache_page+0x9/0x20</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055023] [<ffffffff8013d014>] page_getlink.isra.11+0x24/0x80</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055030] [<ffffffff8013d08f>] page_follow_link_light+0x1f/0x40</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055037] [<ffffffff8013cdb8>] generic_readlink+0x48/0xc0</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055045] [<ffffffff80138134>] sys_readlinkat+0xb4/0xd0</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055055] [<ffffffff8050b20b>] system_call_fastpath+0x1a/0x1f</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055066] [<00007f1a9d19c907>] 0x7f1a9d19c906</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055070] Code: a1 89 e8 5d 41 5c 41 5d c3 0f 1f 84 00 00 00 00 00 40 f6 c7 01 0f 84 1e ff ff ff f0 80 66 01 f7 e9 14 ff ff ff 0f 0b 0f 0b 0f 0b <0f> 0b 0f 0b 48 8b 53 70 c1 e0 09 41 f6 c4 01 89 43 30 89 42 08 </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055123] RIP [<ffffffff801646da>] submit_bh+0x14a/0x1d0</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.055130] RSP <ffff8800ed483c88></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 628.191338] ---[ end trace 84ac243a6201452a ]---</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.145963] BUG: Bad page state in process sshd pfn:36a55</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.145973] page:ffff8800fd3d8298 count:0 mapcount:0 mapping: (null) index:0x2</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.145978] page flags: 0xffffffff80164b90(dirty|slab|owner_priv_1|arch_1|private|head|mappedtodisk|reclaim|unevictable)</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.145993] Modules linked in: bridge stp llc iptable_filter ip_tables x_tables nbd blktap2 pciback usbbk xen_scsibk openvswitch blkbk blkback_pagemap netbk xenbus_be gntdev evtchn ocfs2_dlmfs ocfs2_stack_o2cb ocfs2_dlm bonding af_packet edd ocfs2 ocfs2_nodemanager configfs ocfs2_stackglue quota_tree coretemp domctl crc32c_intel ghash_clmulni_intel joydev iTCO_wdt aesni_intel iTCO_vendor_support ablk_helper cryptd lrw aes_x86_64 hid_generic gpio_ich xts gf128mul 8250_core pcspkr serio_raw igb ixgbe lpc_ich mfd_core i2c_i801 serial_core usbhid sg i7core_edac ioatdma ptp pps_core edac_core hid mdio ses enclosure button uhci_hcd mgag200 ttm drm_kms_helper drm i2c_algo_bit sysimgblt sysfillrect i2c_core syscopyarea ehci_hcd usbcore usb_common processor thermal_sys hwmon scsi_dh_alua scsi_dh_hp_sw scsi_dh_emc scsi_dh_rdac scsi_dh xenblk cdrom xennet ata_generic ata_piix megaraid_sas</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146109] Pid: 5651, comm: sshd Tainted: G D 3.7.9-27-xen #1</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146114] Call Trace:</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146129] [<ffffffff80008ad5>] dump_trace+0x85/0x1c0</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146138] [<ffffffff804f8949>] dump_stack+0x69/0x6f</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146146] [<ffffffff804fac88>] bad_page+0xe7/0xfb</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146155] [<ffffffff800edf4a>] get_page_from_freelist+0x63a/0x750</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146164] [<ffffffff800ee1da>] __alloc_pages_nodemask+0x17a/0x950</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146172] [<ffffffff8010e17b>] handle_pte_fault+0x41b/0x7d0</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146182] [<ffffffff80506ece>] __do_page_fault+0x19e/0x540</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146190] [<ffffffff80503c98>] page_fault+0x28/0x30</p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">[ 643.146200] [<00007fd2d8a9961b>] 0x7fd2d8a9961a</p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">linux-3.7/fs/buffer.c:2952 -> BUG_ON(!bh->b_end_io);</p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">What is the nature of this bug?</p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;">-- </p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><span style=" font-family:'sans serif'; font-weight:600; font-style:italic;">Best regards,</span></p>
<p style=" margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; -qt-user-state:0;"><span style=" font-family:'sans serif'; font-style:italic;">Eugene Istomin</span></p>
<p style="-qt-paragraph-type:empty; margin-top:0px; margin-bottom:0px; margin-left:0px; margin-right:0px; -qt-block-indent:0; text-indent:0px; "> </p></body></html>