Ceph » Linux kernel client

Saw this while testing xfstests on top of kcephfs with fscache enabled:

[ 5905.939357] run fstests generic/451 at 2019-10-21 12:46:38
[ 5923.800347] FS-Cache: 
[ 5923.801031] FS-Cache: Assertion failed
[ 5923.801920] FS-Cache: 1 > 0 is false
[ 5923.802783] ------------[ cut here ]------------
[ 5923.804114] kernel BUG at fs/fscache/cookie.c:736!
[ 5923.805325] invalid opcode: 0000 [#1] SMP NOPTI
[ 5923.806539] CPU: 1 PID: 13472 Comm: xfs_io Tainted: G           O      5.4.0-rc3-00013-g2c77cc335ee8 #23
[ 5923.808428] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-2.fc30 04/01/2014
[ 5923.810403] RIP: 0010:__fscache_disable_cookie.cold+0x2a/0x41 [fscache]
[ 5923.811726] Code: 48 c7 c7 52 b6 40 a0 e8 70 68 d5 e0 48 c7 c7 60 b6 40 a0 e8 64 68 d5 e0 48 63 73 08 31 d2 48 c7 c7 e0 a0 40 a0 e8 52 68 d5 e0 <0f> 0b 48 8b b3 88 00 00 00 48 c7 c7 00 a1 40 a0 e8 3d 68 d5 e0 0f
[ 5923.816448] RSP: 0018:ffffc90000e8fc50 EFLAGS: 00010246
[ 5923.817689] RAX: 0000000000000018 RBX: ffff88842a1df9e0 RCX: 0000000000000000
[ 5923.819088] RDX: 0000000000000000 RSI: ffff88842fa57b98 RDI: ffff88842fa57b98
[ 5923.820420] RBP: ffff888415b29540 R08: ffff88842fa57b98 R09: 0000000000000001
[ 5923.821748] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 5923.823201] R13: 0000000000000003 R14: ffff888415b290a0 R15: ffffc90000e8fde0
[ 5923.824709] FS:  00007faf23e0ac40(0000) GS:ffff88842fa40000(0000) knlGS:0000000000000000
[ 5923.826755] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5923.830188] CR2: 000055583c68e688 CR3: 00000003fe462000 CR4: 00000000000006e0
[ 5923.832471] Call Trace:
[ 5923.833198]  ceph_fscache_file_set_cookie+0xb0/0x120 [ceph]
[ 5923.834472]  ceph_init_file+0x55/0x270 [ceph]
[ 5923.835550]  ? ceph_llseek+0x100/0x100 [ceph]
[ 5923.836639]  do_dentry_open+0x13b/0x380
[ 5923.837611]  path_openat+0x4b4/0xc80
[ 5923.838836]  do_filp_open+0x91/0x100
[ 5923.839652]  ? _raw_spin_unlock+0x24/0x30
[ 5923.840521]  ? __alloc_fd+0xe9/0x1d0
[ 5923.841319]  do_sys_open+0x184/0x220
[ 5923.842146]  do_syscall_64+0x56/0xa0
[ 5923.843183]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 5923.844249] RIP: 0033:0x7faf243d1149
[ 5923.845406] Code: 89 f0 25 00 00 41 00 3d 00 00 41 00 74 4b 8b 05 0d e3 00 00 85 c0 75 6f 44 89 e2 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 9b 00 00 00 48 8b 4c 24 28 64 48 33 0c 25
[ 5923.849267] RSP: 002b:00007ffde032b060 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
[ 5923.850809] RAX: ffffffffffffffda RBX: 0000000000000042 RCX: 00007faf243d1149
[ 5923.852144] RDX: 0000000000000042 RSI: 00007ffde032d8ad RDI: 00000000ffffff9c
[ 5923.853484] RBP: 00007ffde032d8ad R08: 00007ffde032b270 R09: 0000000000000000
[ 5923.855045] R10: 0000000000000180 R11: 0000000000000246 R12: 0000000000000042
[ 5923.856833] R13: 00007ffde032b2b0 R14: 00007ffde032b2b0 R15: 0000000000000180
[ 5923.858153] Modules linked in: ceph libceph dns_resolver fscache(O) rpcsec_gss_krb5 auth_rpcgss loop ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat iptable_mangle iptable_raw iptable_security nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 ip_set nfnetlink ebtable_filter ebtables ip6table_filter ip6_tables sunrpc joydev i2c_piix4 virtio_balloon edac_mce_amd xfs libcrc32c virtio_console virtio_blk virtio_net net_failover failover serio_raw virtio_pci ata_generic pata_acpi floppy virtio_rng virtio_ring virtio [last unloaded: fscache]
[ 5923.870334] ---[ end trace f7a70ea13f0e29ec ]---
[ 5923.871312] RIP: 0010:__fscache_disable_cookie.cold+0x2a/0x41 [fscache]
[ 5923.872603] Code: 48 c7 c7 52 b6 40 a0 e8 70 68 d5 e0 48 c7 c7 60 b6 40 a0 e8 64 68 d5 e0 48 63 73 08 31 d2 48 c7 c7 e0 a0 40 a0 e8 52 68 d5 e0 <0f> 0b 48 8b b3 88 00 00 00 48 c7 c7 00 a1 40 a0 e8 3d 68 d5 e0 0f
[ 5923.876467] RSP: 0018:ffffc90000e8fc50 EFLAGS: 00010246
[ 5923.877690] RAX: 0000000000000018 RBX: ffff88842a1df9e0 RCX: 0000000000000000
[ 5923.879764] RDX: 0000000000000000 RSI: ffff88842fa57b98 RDI: ffff88842fa57b98
[ 5923.881255] RBP: ffff888415b29540 R08: ffff88842fa57b98 R09: 0000000000000001
[ 5923.882602] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 5923.884448] R13: 0000000000000003 R14: ffff888415b290a0 R15: ffffc90000e8fde0
[ 5923.886103] FS:  00007faf23e0ac40(0000) GS:ffff88842fa40000(0000) knlGS:0000000000000000
[ 5923.887763] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5923.888920] CR2: 000055583c68e688 CR3: 00000003fe462000 CR4: 00000000000006e0
[ 5936.288002] run fstests generic/452 at 2019-10-21 12:47:09

This kernel had a test patch to fix a different fscache problem relating to duplicate cookies, so it's possible something is broken in that, but I don't think that's probably the case.