Re: kern/60820: LFS in-kernel cleaner can enter deadlock with build.sh

["Shinichi Doyashiki via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR kern/60820; it has been noted by GNATS.

From: Shinichi Doyashiki <clare%csel.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject:  Re: kern/60820: LFS in-kernel cleaner can enter deadlock with build.sh
Date: Sun, 01 Nov 2026 02:09:56 +0900

 another issue was observed in LFS mount (lfs_reclaimd).
 
 # mount /lfs
 [ 224.8750501] Reader / writer lock error: rw_vector_enter,301: locking against myself
 
 [ 224.8850397] lock address : ffff8e1302ad62b8
 [ 224.8850397] type         : sleep/adaptive
 [ 224.8850397] initialized  : netbsd:lfs_mountfs+0x536
 [ 224.8950340] shared holds :                  0 exclusive:                  1
 [ 224.9050289] shares wanted:                  1 exclusive:                  1
 [ 224.9050289] relevant cpu :                  2 last held:                  1
 [ 224.9150230] relevant lwp : 0xffff8e12fc311800 last held: 0xffff8e12fc311800
 [ 224.9250178] last locked* : netbsd:lfs_reclaimd+0x48
 [ 224.9250178] unlocked     : netbsd:lfs_mountfs+0x12df
 [ 224.9350128] owner/count  : 0xffff8e12fc311800 flags    : 0x0000000000000005
 [ 224.9350128] Turnstile:
 [ 224.9450076] => 1 waiting readers: 0xffff8e12f9040000
 [ 224.9450076] => 0 waiting writers:
 
 [ 224.9450076] panic: LOCKDEBUG: Reader / writer lock error: rw_vector_enter,301: locking against myself
 [ 224.9550056] cpu2: Begin traceback...
 [ 224.9650025] vpanic() at netbsd:vpanic+0x171
 [ 224.9650025] panic() at netbsd:panic+0x4a
 [ 224.9749924] lockdebug_abort1() at netbsd:lockdebug_abort1+0xdd
 [ 224.9849873] rw_enter() at netbsd:rw_enter+0x34d
 [ 224.9849873] lfs_prelock() at netbsd:lfs_prelock+0xaa
 [ 224.9949822] lfs_vfree() at netbsd:lfs_vfree+0xd4
 [ 224.9949822] lfs_reclaim() at netbsd:lfs_reclaim+0x275
 [ 225.0049771] VOP_RECLAIM() at netbsd:VOP_RECLAIM+0x60
 [ 225.0049771] vcache_reclaim() at netbsd:vcache_reclaim+0x1c1
 [ 225.0149720] vrelel() at netbsd:vrelel+0x251
 [ 225.0249669] finfo_func_checkempty() at netbsd:finfo_func_checkempty+0x225
 [ 225.0249669] lfs_parse_pseg() at netbsd:lfs_parse_pseg+0x3f4
 [ 225.0349618] lfs_checkempty() at netbsd:lfs_checkempty+0xfc
 [ 225.0449567] lfs_markclean() at netbsd:lfs_markclean+0x51
 [ 225.0449567] lfs_auto_segclean() at netbsd:lfs_auto_segclean+0x29e
 [ 225.0549517] lfs_reclaimd() at netbsd:lfs_reclaimd+0x50
 [ 225.0549517] cpu2: End traceback...