[LU-7323] ldiskfs: Unknown symbol mb_cache_create (err 0)" on RHEL7

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.9.0
• Labels: easy patch
• Severity: 3
• Assignee: WC Triage
• Reporter: parinay v kondekar (Inactive)

Description

[root@localhost tests]# dmesg | tail -n 50
[   59.614539] Bluetooth: HCI device and connection manager initialized
[   59.614546] Bluetooth: HCI socket layer initialized
[   59.614548] Bluetooth: L2CAP socket layer initialized
[   59.614551] Bluetooth: SCO socket layer initialized
[   59.729078] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[   59.729080] Bluetooth: BNEP filters: protocol multicast
[   59.729088] Bluetooth: BNEP socket layer initialized
[   66.783674] ISO 9660 Extensions: Microsoft Joliet Level 3
[   67.170559] ISO 9660 Extensions: RRIP_1991A
[   67.170596] SELinux: initialized (dev sr0, type iso9660), uses genfs_contexts
[ 1242.262545] libcfs: module verification failed: signature and/or required key missing - tainting kernel
[ 1242.264312] LNet: HW CPU cores: 1, npartitions: 1
[ 1242.402660] alg: No test for adler32 (adler32-zlib)
[ 1242.402673] alg: No test for crc32 (crc32-table)
[ 1250.461533] Lustre: Lustre: Build Version: v2_7_61_0-g888a314-CHANGED-3.10.0lokesh
[ 1250.499066] LNet: Added LNI 10.0.3.15@tcp [8/256/0/180]
[ 1250.499368] LNet: Accept secure, port 988
[ 1250.596779] Lustre: Echo OBD driver; http://www.lustre.org/
[ 1250.902017] ldiskfs: Unknown symbol mb_cache_create (err 0)
[ 1250.902017] ldiskfs: Unknown symbol mb_cache_shrink (err 0)
[ 1250.902643] ldiskfs: Unknown symbol mb_cache_entry_insert (err 0)
[ 1250.902760] ldiskfs: Unknown symbol mb_cache_entry_free (err 0)
[ 1250.902896] ldiskfs: Unknown symbol mb_cache_destroy (err 0)
[ 1250.902973] ldiskfs: Unknown symbol mb_cache_entry_find_first (err 0)
[ 1250.902988] ldiskfs: Unknown symbol mb_cache_entry_alloc (err 0)
[ 1250.903060] ldiskfs: Unknown symbol mb_cache_entry_release (err 0)
[ 1250.903089] ldiskfs: Unknown symbol mb_cache_entry_get (err 0)
[ 1250.903143] ldiskfs: Unknown symbol mb_cache_entry_find_next (err 0)
[ 3669.933621] TCP: lp registered
[ 5153.850625] ldiskfs: Unknown symbol mb_cache_create (err 0)
[ 5153.850799] ldiskfs: Unknown symbol mb_cache_shrink (err 0)
[ 5153.850940] ldiskfs: Unknown symbol mb_cache_entry_insert (err 0)
[ 5153.850980] ldiskfs: Unknown symbol mb_cache_entry_free (err 0)
[ 5153.851195] ldiskfs: Unknown symbol mb_cache_destroy (err 0)
[ 5153.851247] ldiskfs: Unknown symbol mb_cache_entry_find_first (err 0)
[ 5153.851299] ldiskfs: Unknown symbol mb_cache_entry_alloc (err 0)
[ 5153.851305] ldiskfs: Unknown symbol mb_cache_entry_release (err 0)
[ 5153.851319] ldiskfs: Unknown symbol mb_cache_entry_get (err 0)
[ 5153.851369] ldiskfs: Unknown symbol mb_cache_entry_find_next (err 0)
[ 5499.827021] atkbd serio0: Spurious NAK on isa0060/serio0. Some program might be trying to access hardware directly.
[10476.657966] ldiskfs: Unknown symbol mb_cache_create (err 0)
[10476.657990] ldiskfs: Unknown symbol mb_cache_shrink (err 0)
[10476.658204] ldiskfs: Unknown symbol mb_cache_entry_insert (err 0)
[10476.658334] ldiskfs: Unknown symbol mb_cache_entry_free (err 0)
[10476.658491] ldiskfs: Unknown symbol mb_cache_destroy (err 0)
[10476.658566] ldiskfs: Unknown symbol mb_cache_entry_find_first (err 0)
[10476.658641] ldiskfs: Unknown symbol mb_cache_entry_alloc (err 0)
[10476.658652] ldiskfs: Unknown symbol mb_cache_entry_release (err 0)
[10476.658674] ldiskfs: Unknown symbol mb_cache_entry_get (err 0)
[10476.658753] ldiskfs: Unknown symbol mb_cache_entry_find_next (err 0)
 

loading mbcache module resolves it,

From Shadow
"if someone see a bug like "ldiskfs: Unknown symbol mb_cache_create (err 0)" on RHEL7 - it's mean mbcache module isn't loaded. before RHEL7 it was part of ext4, but EL7 have a mbcache as separate module and need a extra modprobe mbcache command before run tests from local build dir. It's bug in test-framework.sh."