On Mon, Jun 17, 2024 at 5:32 PM Christoph Hellwig <hch@xxxxxx> wrote: > > On Sun, Jun 16, 2024 at 06:23:16PM +0800, Barry Song wrote: > > This is quite unusual. Could you share your setup and backtrace? > > Do this in an x86 kvm vm with 1G of memory: > > mkfs.xfs -f /dev/vdb > > mount /dev/vdb /mnt/nfs1 > > # this requires the following line in /etc/exports to actually export the > # file system: "/mnt/nfs2 localhost(rw,no_root_squash)" > systemctl restart nfs-kernel-server > > mount -t nfs 127.0.0.1:/mnt/nfs1/ /mnt/test/ > > cd /mnt/test > dd if=/dev/zero of=swapfile bs=1024 count=524288 > mkswap swapfile > chmod 0600 swapfile > swapon swapfile I did everything the same as above, but always got failure at the last step to swapon: /mnt/test # swapon swapfile swapon: /mnt/test/swapfile: swapon failed: Invalid argument the mount status: /dev/vdb on /mnt/nfs1 type xfs (rw,relatime,attr2,inode64,logbufs=8,logbsize=32k,noquota) 127.0.0.1:/mnt/nfs1 on /mnt/test type nfs4 (rw,relatime,vers=4.2,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=sys,clientaddr=127.0.0.1,local_lock=none,addr=127.0.0.1) As long as the swapfile is not on nfs, I am ok to swapon: /mnt # swapon swapfile [ 1150.302641] Adding 65532k swap on /mnt/swapfile. Priority:-2 extents:1 across:65532k Anything I am missing? > > # xfstests-dev is a checked out and built xfstests repo > ~/xfstests-dev/src/usemem 1024 > > The backtrace is at the end of the mail. > > > I'd > > like to reproduce the issue, as the mm code only supports mTHP > > swapout on block devices. What is your swap device or swap file? > > The above swap fіle on NFS is the only swap in the system > > > Additionally, on what kind of filesystem is the executable file built > > from usemem.c located? > > Doesn't matter. I've tried xfs, ext4 and nfs itself. > > root@testvm:~# ./xfstests-dev/src/usemem 1024 > [ 65.065292] ------------[ cut here ]------------ > [ 65.065528] kernel BUG at fs/nfs/direct.c:144! > [ 65.065724] Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > [ 65.065988] CPU: 0 PID: 71 Comm: kswapd0 Not tainted 6.10.0-rc3+ #2587 > [ 65.066270] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 > [ 65.066683] RIP: 0010:nfs_swap_rw+0x3f/0x50 > [ 65.066893] Code: 00 00 74 13 e8 e2 fb ff ff 31 d2 48 85 c0 48 0f 4f c2 c3 cc cc cc cc e8 9f f8 ff ff 31 0 > [ 65.067698] RSP: 0018:ffffc900001b79c8 EFLAGS: 00010206 > [ 65.067949] RAX: ffffffff8162afc0 RBX: ffff88800ca24c00 RCX: 0000000000000004 > [ 65.068274] RDX: ffff88800ca24c30 RSI: ffffc900001b79d0 RDI: ffff88800ca24c00 > [ 65.068588] RBP: ffff88800dd710e8 R08: 0000000000004000 R09: 0000000000000010 > [ 65.068911] R10: 0000000000035a40 R11: 000000000000001d R12: ffffc900001b7a78 > [ 65.069225] R13: ffffc900001b7db0 R14: ffffc900001b7a68 R15: ffffea00003f1c40 > [ 65.069542] FS: 0000000000000000(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000 > [ 65.069904] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 65.070157] CR2: 00005606ddec4dd0 CR3: 000000000365a003 CR4: 0000000000770ef0 > [ 65.070472] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 65.070784] DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400 > [ 65.071282] PKRU: 55555554 > [ 65.071407] Call Trace: > [ 65.071519] <TASK> > [ 65.071619] ? die+0x31/0x80 > [ 65.071754] ? do_trap+0xd7/0x100 > [ 65.071915] ? do_error_trap+0x65/0x90 > [ 65.072084] ? nfs_swap_rw+0x3f/0x50 > [ 65.072247] ? exc_invalid_op+0x50/0x70 > [ 65.072420] ? nfs_swap_rw+0x3f/0x50 > [ 65.072581] ? asm_exc_invalid_op+0x1a/0x20 > [ 65.072770] ? __pfx_nfs_swap_rw+0x10/0x10 > [ 65.072966] ? nfs_swap_rw+0x3f/0x50 > [ 65.073125] swap_write_unplug+0x57/0x90 > [ 65.073307] shrink_folio_list+0x3a1/0xed0 > [ 65.073500] ? __mod_zone_page_state+0x61/0xa0 > [ 65.073700] ? isolate_lru_folios+0x2f3/0x400 > [ 65.073902] shrink_lruvec+0x587/0xb60 > [ 65.074071] ? shrink_slab+0x3ad/0x3c0 > [ 65.074239] ? shrink_slab+0x3ad/0x3c0 > [ 65.074408] shrink_node+0x2b7/0x7e0 > [ 65.074569] balance_pgdat+0x291/0x6f0
