On Tue, Nov 26, 2019 at 10:52:04PM +0100, David Sterba wrote: > On Mon, Nov 25, 2019 at 02:46:40PM -0500, Dennis Zhou wrote: > > Hello, > > > > v3 [1] had 2 minor issues which are fixed: > > - I was generically dividing u64 which made 32 bit arches unhappy. [2] > > - Uninitialized use of trim_state local variable [3] > > I've started fstests (misc-5.5 + v4) with some debugging options > compiled in and MOUNT_OPTIONS -o discard=async: > > btrfs/003: > > [ 57.263321] BTRFS info (device vdb): relocating block group 30408704 flags metadata|dup > [ 57.321441] BTRFS info (device vdb): found 8 extents > [ 57.352217] list_add corruption. prev->next should be next (ffff89b6b157f1e0), but was 6b6b6b6b6b6b6b6b. (prev=ffff89b6b3cc59f0). > [ 57.355426] ------------[ cut here ]------------ > [ 57.356895] kernel BUG at lib/list_debug.c:26! > [ 57.358303] invalid opcode: 0000 [#1] SMP > [ 57.359522] CPU: 1 PID: 19415 Comm: btrfs Not tainted 5.4.0-rc8-default+ #878 > [ 57.361334] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-rebuilt.opensuse.org 04/01/2014 > [ 57.364468] RIP: 0010:__list_add_valid+0x5e/0x70 > [ 57.369959] RSP: 0018:ffff90cbc4c7f8d0 EFLAGS: 00010246 > [ 57.371475] RAX: 0000000000000075 RBX: ffff89b6b3d04000 RCX: 0000000000000006 > [ 57.372930] RDX: 0000000000000000 RSI: ffff89b6b2314030 RDI: ffff89b6b2313740 > [ 57.374893] RBP: ffff89b6b157f0d0 R08: 0000000d5aa62d0d R09: 0000000000000000 > [ 57.376970] R10: 0000000000000000 R11: 0000000000000000 R12: ffff89b6b3d041f0 > [ 57.378961] R13: ffff89b6b3cc59f0 R14: ffff89b6b157f190 R15: ffff89b6b157f1e0 > [ 57.381012] FS: 00007f551b41d8c0(0000) GS:ffff89b6bd800000(0000) knlGS:0000000000000000 > [ 57.383531] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 57.385264] CR2: 0000563d526212d8 CR3: 0000000073dd3004 CR4: 0000000000160ee0 > [ 57.387223] Call Trace: > [ 57.388250] btrfs_add_to_discard_unused_list+0xa2/0xe0 [btrfs] > [ 57.389804] btrfs_discard_queue_work+0x3a/0x60 [btrfs] > [ 57.390961] __btrfs_add_free_space+0xe2/0x400 [btrfs] > [ 57.401053] ? do_raw_spin_unlock+0x4b/0xc0 > [ 57.402419] ? _raw_spin_unlock+0x24/0x30 > [ 57.403791] ? find_first_extent_bit+0xdc/0x120 [btrfs] > [ 57.405312] add_new_free_space+0xd1/0xf0 [btrfs] > [ 57.406723] btrfs_make_block_group+0x9f/0x2e0 [btrfs] > [ 57.408222] __btrfs_alloc_chunk+0x705/0xf00 [btrfs] > [ 57.409786] btrfs_chunk_alloc+0x1a9/0x3f0 [btrfs] > [ 57.411354] btrfs_inc_block_group_ro+0x16d/0x190 [btrfs] > [ 57.412897] btrfs_relocate_block_group+0x60/0x300 [btrfs] > [ 57.414430] btrfs_relocate_chunk+0x32/0xd0 [btrfs] > [ 57.415747] __btrfs_balance+0x41c/0xcc0 [btrfs] > [ 57.417084] btrfs_balance+0x56e/0xa40 [btrfs] > [ 57.418361] ? kmem_cache_alloc_trace+0x281/0x2c0 > [ 57.419448] btrfs_ioctl_balance+0x298/0x350 [btrfs] > [ 57.420568] ? mem_cgroup_throttle_swaprate+0xcb/0x2a8 > [ 57.422306] btrfs_ioctl+0x466/0x2570 [btrfs] > [ 57.423648] ? __handle_mm_fault+0x499/0x740 > [ 57.425008] ? kvm_sched_clock_read+0x14/0x30 > [ 57.426311] ? sched_clock+0x5/0x10 > [ 57.427480] ? sched_clock_cpu+0x10/0x120 > [ 57.428856] ? __handle_mm_fault+0x499/0x740 > [ 57.430314] ? do_raw_spin_unlock+0x4b/0xc0 > [ 57.431695] ? _raw_spin_unlock+0x24/0x30 > [ 57.432997] ? __handle_mm_fault+0x499/0x740 > [ 57.434370] ? do_vfs_ioctl+0x405/0x730 > [ 57.435920] do_vfs_ioctl+0x405/0x730 > [ 57.437439] ? do_user_addr_fault+0x1f1/0x3c0 > [ 57.439096] ksys_ioctl+0x3a/0x70 > [ 57.440518] ? trace_hardirqs_off_thunk+0x1a/0x20 > [ 57.442159] __x64_sys_ioctl+0x16/0x20 > [ 57.443315] do_syscall_64+0x50/0x1f0 > [ 57.444252] entry_SYSCALL_64_after_hwframe+0x49/0xbek Sigh, I'm sorry about these issues with the series. I think this is being racy in btrfs_delete_unused_bgs(). I'm working on setting up the reproducer and fixing it. Thanks, Dennis
