On Mon, Apr 21, 2025 at 11:14:44AM -0400, Kent Overstreet wrote: > This just popped up in one of my test runs. > > Given that it's buffer heads, it has to be the ext4 root filesystem, not > bcachefs. Wrong. udev calling libblkid reading the (mounted) bdev to figure out there's a bcachefs filesystem will still create bufferheads, and possibly very large ones. willy's temporary workaround in https://lore.kernel.org/linux-fsdevel/Z_VwF1MA-R7MgDVG@xxxxxxxxxxxxxxxxxxxx/ shuts all that up enough to move on to triaging the rest of the bleeding. --D > 00465 ========= TEST lz4_buffered > 00465 > 00465 WATCHDOG 360 > 00466 bcachefs (vdb): starting version 1.25: extent_flags opts=errors=panic,compression=lz4 > 00466 bcachefs (vdb): initializing new filesystem > 00466 bcachefs (vdb): going read-write > 00466 bcachefs (vdb): marking superblocks > 00466 bcachefs (vdb): initializing freespace > 00466 bcachefs (vdb): done initializing freespace > 00466 bcachefs (vdb): reading snapshots table > 00466 bcachefs (vdb): reading snapshots done > 00466 bcachefs (vdb): done starting filesystem > 00466 starting copy > 00515 BUG: sleeping function called from invalid context at mm/util.c:743 > 00515 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 120, name: kcompactd0 > 00515 preempt_count: 1, expected: 0 > 00515 RCU nest depth: 0, expected: 0 > 00515 1 lock held by kcompactd0/120: > 00515 #0: ffffff80c0c558f0 (&mapping->i_private_lock){+.+.}-{3:3}, at: __buffer_migrate_folio+0x114/0x298 > 00515 Preemption disabled at: > 00515 [<ffffffc08025fa84>] __buffer_migrate_folio+0x114/0x298 > 00515 CPU: 11 UID: 0 PID: 120 Comm: kcompactd0 Not tainted 6.15.0-rc3-ktest-gb2a78fdf7d2f #20530 PREEMPT > 00515 Hardware name: linux,dummy-virt (DT) > 00515 Call trace: > 00515 show_stack+0x1c/0x30 (C) > 00515 dump_stack_lvl+0xb0/0xc0 > 00515 dump_stack+0x14/0x20 > 00515 __might_resched+0x180/0x288 > 00515 folio_mc_copy+0x54/0x98 > 00515 __migrate_folio.isra.0+0x68/0x168 > 00515 __buffer_migrate_folio+0x280/0x298 > 00515 buffer_migrate_folio_norefs+0x18/0x28 > 00515 migrate_pages_batch+0x94c/0xeb8 > 00515 migrate_pages_sync+0x84/0x240 > 00515 migrate_pages+0x284/0x698 > 00515 compact_zone+0xa40/0x10f8 > 00515 kcompactd_do_work+0x204/0x498 > 00515 kcompactd+0x3c4/0x400 > 00515 kthread+0x13c/0x208 > 00515 ret_from_fork+0x10/0x20 > 00518 starting sync > 00519 starting rm > 00520 ========= FAILED TIMEOUT lz4_buffered in 360s > >
