From: Desmond Cheong Zhi Xi desmondcheongzx@gmail.com
commit 0d977e0eba234e01a60bdde27314dc21374201b3 upstream.
This crash was observed with a failed assertion on device close:
BTRFS: Transaction aborted (error -28) WARNING: CPU: 1 PID: 3902 at fs/btrfs/extent-tree.c:2150 btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs] Modules linked in: btrfs blake2b_generic libcrc32c crc32c_intel xor zstd_decompress zstd_compress xxhash lzo_compress lzo_decompress raid6_pq loop CPU: 1 PID: 3902 Comm: kworker/u8:4 Not tainted 5.14.0-rc5-default+ #1532 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 Workqueue: events_unbound btrfs_async_reclaim_metadata_space [btrfs] RIP: 0010:btrfs_run_delayed_refs+0x1d2/0x1e0 [btrfs] RSP: 0018:ffffb7a5452d7d80 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffffffabee13c4 RDI: 00000000ffffffff RBP: ffff97834176a378 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff97835195d388 R13: 0000000005b08000 R14: ffff978385484000 R15: 000000000000016c FS: 0000000000000000(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056190d003fe8 CR3: 000000002a81e005 CR4: 0000000000170ea0 Call Trace: flush_space+0x197/0x2f0 [btrfs] btrfs_async_reclaim_metadata_space+0x139/0x300 [btrfs] process_one_work+0x262/0x5e0 worker_thread+0x4c/0x320 ? process_one_work+0x5e0/0x5e0 kthread+0x144/0x170 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 irq event stamp: 19334989 hardirqs last enabled at (19334997): [<ffffffffab0e0c87>] console_unlock+0x2b7/0x400 hardirqs last disabled at (19335006): [<ffffffffab0e0d0d>] console_unlock+0x33d/0x400 softirqs last enabled at (19334900): [<ffffffffaba0030d>] __do_softirq+0x30d/0x574 softirqs last disabled at (19334893): [<ffffffffab0721ec>] irq_exit_rcu+0x12c/0x140 ---[ end trace 45939e308e0dd3c7 ]--- BTRFS: error (device vdd) in btrfs_run_delayed_refs:2150: errno=-28 No space left BTRFS info (device vdd): forced readonly BTRFS warning (device vdd): failed setting block group ro: -30 BTRFS info (device vdd): suspending dev_replace for unmount assertion failed: !test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state), in fs/btrfs/volumes.c:1150 ------------[ cut here ]------------ kernel BUG at fs/btrfs/ctree.h:3431! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 3982 Comm: umount Tainted: G W 5.14.0-rc5-default+ #1532 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba527-rebuilt.opensuse.org 04/01/2014 RIP: 0010:assertfail.constprop.0+0x18/0x1a [btrfs] RSP: 0018:ffffb7a5454c7db8 EFLAGS: 00010246 RAX: 0000000000000068 RBX: ffff978364b91c00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffffabee13c4 RDI: 00000000ffffffff RBP: ffff9783523a4c00 R08: 0000000000000001 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: ffff9783523a4d18 R13: 0000000000000000 R14: 0000000000000004 R15: 0000000000000003 FS: 00007f61c8f42800(0000) GS:ffff9783bd800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000056190cffa810 CR3: 0000000030b96002 CR4: 0000000000170ea0 Call Trace: btrfs_close_one_device.cold+0x11/0x55 [btrfs] close_fs_devices+0x44/0xb0 [btrfs] btrfs_close_devices+0x48/0x160 [btrfs] generic_shutdown_super+0x69/0x100 kill_anon_super+0x14/0x30 btrfs_kill_super+0x12/0x20 [btrfs] deactivate_locked_super+0x2c/0xa0 cleanup_mnt+0x144/0x1b0 task_work_run+0x59/0xa0 exit_to_user_mode_loop+0xe7/0xf0 exit_to_user_mode_prepare+0xaf/0xf0 syscall_exit_to_user_mode+0x19/0x50 do_syscall_64+0x4a/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae
This happens when close_ctree is called while a dev_replace hasn't completed. In close_ctree, we suspend the dev_replace, but keep the replace target around so that we can resume the dev_replace procedure when we mount the root again. This is the call trace:
close_ctree(): btrfs_dev_replace_suspend_for_unmount(); btrfs_close_devices(): btrfs_close_fs_devices(): btrfs_close_one_device(): ASSERT(!test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
However, since the replace target sticks around, there is a device with BTRFS_DEV_STATE_REPLACE_TGT set on close, and we fail the assertion in btrfs_close_one_device.
To fix this, if we come across the replace target device when closing, we should properly reset it back to allocation state. This fix also ensures that if a non-target device has a corrupted state and has the BTRFS_DEV_STATE_REPLACE_TGT bit set, the assertion will still catch the error.
Reported-by: David Sterba dsterba@suse.com Fixes: b2a616676839 ("btrfs: fix rw device counting in __btrfs_free_extra_devids") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Anand Jain anand.jain@oracle.com Signed-off-by: Desmond Cheong Zhi Xi desmondcheongzx@gmail.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/volumes.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1048,6 +1048,9 @@ static void btrfs_close_one_device(struc fs_devices->rw_devices--; }
+ if (device->devid == BTRFS_DEV_REPLACE_DEVID) + clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state); + if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) fs_devices->missing_devices--;