Bug 251729

Summary:	LOR between isofs and bufwait
Product:	Base System	Reporter:	Gordon Bergling <gbe>
Component:	kern	Assignee:	freebsd-bugs (Nobody) <bugs>
Status:	Closed Overcome By Events
Severity:	Affects Some People
Priority:	---
Version:	CURRENT
Hardware:	Any
OS:	Any

Description Gordon Bergling freebsd_committer

2020-12-10 14:22:29 UTC

The following LOR was reported while running kyua test on arm64.

lock order reversal:
1st 0xffffa000d79999f8 isofs (isofs, lockmgr) @ /tank/nfs_public/tiny/src/sys/kern/vfs_syscalls.c
:4165
2nd 0xffff0000409378e0 bufwait (bufwait, lockmgr) @ /tank/nfs_public/tiny/src/sys/kern/vfs_bio.c:
1674
lock order isofs -> bufwait attempted at:
#0 0xffff000000570d90 at witness_checkorder+0xc54
#1 0xffff0000004d3318 at lockmgr_xlock_hard+0x6c
#2 0xffff0000004d3fbc at __lockmgr_args+0x534
#3 0xffff0000005bad10 at getnewbuf+0x48c
#4 0xffff0000005b7e34 at getblkx+0x2d0
#5 0xffff0000005b7974 at breadn_flags+0x54
#6 0xffff0000004833d4 at cd9660_blkatoff+0x58
#7 0xffff000000486e10 at cd9660_readdir+0x170
#8 0xffff00000089373c at VOP_READDIR_APV+0x44
#9 0xffff0000005f1a58 at kern_getdirentries+0x1fc
#10 0xffff0000005f1c9c at sys_getdirentries+0x24
#11 0xffff0000008241f4 at do_el0_sync+0x7dc
#12 0xffff000000803a24 at handle_el0_sync+0x90