Hi all, I experience failed assertions on an x86_64 KVM virtual machine (VirtIO devices) when accessing files on NFS 4 shares while having cachefilesd (0.10.7) running. Good kernel: 4.14.49 Bad kernels: 5.8.14, 5.9.0 The machine is rendered unusable (100% CPU) and requires a hard-reset. This is the console error report captured via serial console: CacheFiles: CacheFiles: Assertion failed invalid opcode: 0000 [#1] CPU: 0 PID: 4215 Comm: git Not tainted 5.9.0vzlinux #3 RIP: 0010:cachefiles_read_or_alloc_pages+0x9e/0x5cf Code: ff 0f 0b 49 8b 46 30 48 8b 40 70 48 83 78 20 00 75 1a 48 c7 c7 20 fc e8 81 e8 cf 7a e7 ff 48 c7 c7 30 fc e8 81 e8 c3 7a e7 ff <0f> 0b 49 8b 46 28 ba 0c 00 00 00 c6 44 24 40 00 c6 44 24 41 00 c7 RSP: 0000:ffffc900015cba98 EFLAGS: 00010292 RAX: 000000000000001c RBX: ffffc900015cbc04 RCX: 0000000000000027 RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff82039340 RBP: ffff88803c3469c0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000001e88c R11: 000000000000003c R12: ffffc900015cbd70 R13: ffff88803c3469c0 R14: ffff88802e2d2fd0 R15: ffff88802bf27000 FS: 00007feea1027fc0(0000) GS:ffffffff82030000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feea1036000 CR3: 000000002bcbd005 CR4: 00000000001706b0 Call Trace: ? nfs_access_add_cache+0x140/0x1c5 ? slab_free_freelist_hook+0x45/0xc4 ? slab_pre_alloc_hook.isra.81+0x26/0x37 ? fscache_run_op.isra.13+0x57/0x69 __fscache_read_or_alloc_pages+0x1a6/0x1f2 __nfs_readpages_from_fscache+0x51/0xa9 nfs_readpages+0x111/0x133 ? get_page_from_freelist+0x734/0x8a1 read_pages+0x8c/0x102 ? __alloc_pages_nodemask+0xd4/0x122 ? page_cache_readahead_unbounded+0xce/0x17d page_cache_readahead_unbounded+0xce/0x17d filemap_fault+0x1f9/0x3d8 __do_fault+0x44/0x63 handle_mm_fault+0x70e/0xad3 exc_page_fault+0x1f0/0x311 ? asm_exc_page_fault+0x5/0x20 asm_exc_page_fault+0x1b/0x20 RIP: 0033:0x7feea0991bef Code: 41 c7 45 00 1d 00 00 00 e9 1e f8 ff ff 41 8b 55 08 85 d2 0f 84 72 07 00 00 83 fb 0f 0f 87 37 14 00 00 85 ed 0f 84 83 f5 ff ff <41> 0f b6 34 24 89 d9 8d 45 ff 49 8d 7c 24 01 48 d3 e6 8d 4b 08 4c RSP: 002b:00007fffbb7d5240 EFLAGS: 00010202 RAX: 00007feea0991bd2 RBX: 0000000000000000 RCX: 00000000000000d0 RDX: 0000000000000001 RSI: 000055d7e1bf9c10 RDI: 00007fffbb7d52a0 RBP: 00000000000000d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 00007fffbb7d5390 R12: 00007feea1036000 R13: 000055d7e1bf9900 R14: 00007fffbb7d5570 R15: 0000000000000000 ---[ end trace cad4b4a2dd601cdd ]--- RIP: 0010:cachefiles_read_or_alloc_pages+0x9e/0x5cf Code: ff 0f 0b 49 8b 46 30 48 8b 40 70 48 83 78 20 00 75 1a 48 c7 c7 20 fc e8 81 e8 cf 7a e7 ff 48 c7 c7 30 fc e8 81 e8 c3 7a e7 ff <0f> 0b 49 8b 46 28 ba 0c 00 00 00 c6 44 24 40 00 c6 44 24 41 00 c7 RSP: 0000:ffffc900015cba98 EFLAGS: 00010292 RAX: 000000000000001c RBX: ffffc900015cbc04 RCX: 0000000000000027 RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffffff82039340 RBP: ffff88803c3469c0 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000001e88c R11: 000000000000003c R12: ffffc900015cbd70 R13: ffff88803c3469c0 R14: ffff88802e2d2fd0 R15: ffff88802bf27000 FS: 00007feea1027fc0(0000) GS:ffffffff82030000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feea1036000 CR3: 000000002bcbd005 CR4: 00000000001706b0 Kernel panic - not syncing: Fatal exception Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception ]--- Feel free to ask for further info or testing patches. Thank you! Regards, Jonas Zeiger Ps: I found this mail https://lkml.org/lkml/2020/3/20/399 describing a similar issue, but it may be unrelated.
