2:37 p.m.
Hi,
Copying files to vfat FS on an NVDIMM device hits
BUG_ON(!PageLocked(page)) in try_to_free_buffers(). It happens on
4.13-rc1, and happens on older kernels as well.
A simple reproducer is shown below. It is 100% reproducible on my
setup (8GB of regular memory and 16GB of NVDIMM). It usually hits in
the 3rd or 4th file copy and does not repeat with the while-loop.
Interestingly, it hits only when an NVDIMM device is set as raw or
memory mode. It does not hit with sector mode.
==
DEV=pmem0
set -x
mkfs.vfat /dev/$DEV
mount /dev/$DEV /mnt/$DEV
dd if=/dev/zero of=/mnt/$DEV/1Gfile bs=1M count=1024
while true; do
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-1
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-2
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-3
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-4
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-5
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-6
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-7
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-8
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-9
cp /mnt/$DEV/1Gfile /mnt/$DEV/file-10
done
==
kernel BUG at fs/buffer.c:3305!
invalid opcode: 0000 [#1] SMP
:
Workqueue: writeback wb_workfn (flush-259:0)
task: ffff8d02595b8000 task.stack: ffffa22242400000
RIP: 0010:try_to_free_buffers+0xd2/0xe0
RSP: 0018:ffffa22242403830 EFLAGS: 00010246
RAX: 00afffc000001028 RBX: 0000000000000008 RCX: ffff8d012dcf19c0
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffc468e3b52b80
RBP: ffffa22242403858 R08: 0000000000000000 R09: 000000000002067c
R10: ffff8d027ffe6000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8d022fccdbe0 R14: ffffc468e3b52b80 R15: ffffa22242403ad0
FS: 0000000000000000(0000) GS:ffff8d027fd40000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9d2bb80b70 CR3: 000000084fe09000 CR4: 00000000007406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
clean_buffers+0x5d/0x70
__mpage_writepage+0x567/0x760
? page_mkclean+0x6a/0xb0
write_cache_pages+0x205/0x580
? clean_buffers+0x70/0x70
? fat_add_cluster+0x80/0x80 [fat]
mpage_writepages+0x7c/0x100
? fat_add_cluster+0x80/0x80 [fat]
? __set_page_dirty+0x9b/0xc0
? fprop_fraction_percpu+0x2f/0x80
fat_writepages+0x15/0x20 [fat]
? fat_writepages+0x15/0x20 [fat]
do_writepages+0x25/0x80
__writeback_single_inode+0x45/0x350
writeback_sb_inodes+0x25e/0x610
__writeback_inodes_wb+0x92/0xc0
wb_writeback+0x29b/0x340
wb_workfn+0x195/0x3d0
? wb_workfn+0x195/0x3d0
process_one_work+0x193/0x3d0
worker_thread+0x4e/0x3d0
kthread+0x114/0x150
? process_one_work+0x3d0/0x3d0
? kthread_park+0x60/0x60
? kthread_park+0x60/0x60
ret_from_fork+0x25/0x30
:
RIP: try_to_free_buffers+0xd2/0xe0 RSP: ffffa22242403830
Thanks,
-Toshi