BTRFS info (device loop1): using sha256 (sha256-avx2) checksum algorithm BTRFS info (device loop1): using free space tree BTRFS info (device loop1): enabling ssd optimizations ====================================================== WARNING: possible circular locking dependency detected 6.1.0-rc6-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.1/9043 is trying to acquire lock: ffff88801523e650 (sb_internal#2){.+.+}-{0:0}, at: btrfs_dirty_inode+0xf4/0x250 fs/btrfs/inode.c:6085 but task is already holding lock: ffff88801f0f2cd8 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] ffff88801f0f2cd8 (&mm->mmap_lock#2){++++}-{3:3}, at: vm_mmap_pgoff+0x159/0x280 mm/util.c:518 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&mm->mmap_lock#2){++++}-{3:3}: __might_fault mm/memory.c:5646 [inline] __might_fault+0x10c/0x180 mm/memory.c:5639 _copy_to_user+0x29/0x150 lib/usercopy.c:29 copy_to_user include/linux/uaccess.h:169 [inline] btrfs_ioctl_get_subvol_rootref+0x74e/0xad0 fs/btrfs/ioctl.c:3203 btrfs_ioctl+0x2de6/0x5be0 fs/btrfs/ioctl.c:5556 __do_compat_sys_ioctl+0x255/0x2b0 fs/ioctl.c:968 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #4 (btrfs-root-00){++++}-{3:3}: down_write_nested+0x98/0x220 kernel/locking/rwsem.c:1672 __btrfs_tree_lock+0x32/0x3d0 fs/btrfs/locking.c:196 btrfs_tree_lock fs/btrfs/locking.c:203 [inline] btrfs_lock_root_node+0x61/0x90 fs/btrfs/locking.c:256 commit_cowonly_roots+0x13c/0xa10 fs/btrfs/transaction.c:1266 btrfs_commit_transaction+0xb93/0x36e0 fs/btrfs/transaction.c:2376 btrfs_commit_super+0xc5/0x100 fs/btrfs/disk-io.c:4499 close_ctree+0x39c/0xdc7 fs/btrfs/disk-io.c:4653 generic_shutdown_super+0x158/0x410 fs/super.c:492 kill_anon_super+0x3a/0x60 fs/super.c:1086 btrfs_kill_super+0x3c/0x50 fs/btrfs/super.c:2441 deactivate_locked_super+0x98/0x160 fs/super.c:332 deactivate_super+0xb1/0xd0 fs/super.c:363 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1186 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #3 (&fs_info->reloc_mutex){+.+.}-{3:3}: __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1360 kernel/locking/mutex.c:747 btrfs_record_root_in_trans+0x13d/0x1b0 fs/btrfs/transaction.c:484 start_transaction+0x295/0x1470 fs/btrfs/transaction.c:721 btrfs_create_common+0x1aa/0x260 fs/btrfs/inode.c:6633 btrfs_create+0x116/0x160 fs/btrfs/inode.c:6679 lookup_open.isra.0+0xf05/0x12a0 fs/namei.c:3413 open_last_lookups fs/namei.c:3481 [inline] path_openat+0x996/0x2860 fs/namei.c:3710 do_filp_open+0x1ba/0x410 fs/namei.c:3740 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_compat_sys_openat fs/open.c:1386 [inline] __se_compat_sys_openat fs/open.c:1384 [inline] __ia32_compat_sys_openat+0x143/0x1f0 fs/open.c:1384 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #2 (btrfs_trans_num_extwriters){++++}-{0:0}: join_transaction+0x1b3/0x10f0 fs/btrfs/transaction.c:299 start_transaction+0x407/0x1470 fs/btrfs/transaction.c:658 btrfs_commit_super+0x9d/0x100 fs/btrfs/disk-io.c:4496 close_ctree+0x39c/0xdc7 fs/btrfs/disk-io.c:4653 generic_shutdown_super+0x158/0x410 fs/super.c:492 kill_anon_super+0x3a/0x60 fs/super.c:1086 btrfs_kill_super+0x3c/0x50 fs/btrfs/super.c:2441 deactivate_locked_super+0x98/0x160 fs/super.c:332 deactivate_super+0xb1/0xd0 fs/super.c:363 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1186 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #1 (btrfs_trans_num_writers){++++}-{0:0}: join_transaction+0x18e/0x10f0 fs/btrfs/transaction.c:298 start_transaction+0x407/0x1470 fs/btrfs/transaction.c:658 btrfs_commit_super+0x9d/0x100 fs/btrfs/disk-io.c:4496 close_ctree+0x39c/0xdc7 fs/btrfs/disk-io.c:4653 generic_shutdown_super+0x158/0x410 fs/super.c:492 kill_anon_super+0x3a/0x60 fs/super.c:1086 btrfs_kill_super+0x3c/0x50 fs/btrfs/super.c:2441 deactivate_locked_super+0x98/0x160 fs/super.c:332 deactivate_super+0xb1/0xd0 fs/super.c:363 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1186 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296 __do_fast_syscall_32+0x72/0xf0 arch/x86/entry/common.c:181 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 -> #0 (sb_internal#2){.+.+}-{0:0}: check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x878/0x1470 fs/btrfs/transaction.c:652 btrfs_dirty_inode+0xf4/0x250 fs/btrfs/inode.c:6085 btrfs_update_time+0x25a/0x2c0 fs/btrfs/inode.c:6127 inode_update_time fs/inode.c:1871 [inline] touch_atime+0x41f/0x700 fs/inode.c:1944 file_accessed include/linux/fs.h:2521 [inline] btrfs_file_mmap+0x119/0x150 fs/btrfs/file.c:2333 call_mmap include/linux/fs.h:2196 [inline] mmap_region+0x6c3/0x1dd0 mm/mmap.c:2625 do_mmap+0x831/0xf60 mm/mmap.c:1412 vm_mmap_pgoff+0x1af/0x280 mm/util.c:520 ksys_mmap_pgoff+0x41f/0x5a0 mm/mmap.c:1458 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 other info that might help us debug this: Chain exists of: sb_internal#2 --> btrfs-root-00 --> &mm->mmap_lock#2 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&mm->mmap_lock#2); lock(btrfs-root-00); lock(&mm->mmap_lock#2); lock(sb_internal#2); *** DEADLOCK *** 2 locks held by syz-executor.1/9043: #0: ffff88801f0f2cd8 (&mm->mmap_lock#2){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline] #0: ffff88801f0f2cd8 (&mm->mmap_lock#2){++++}-{3:3}, at: vm_mmap_pgoff+0x159/0x280 mm/util.c:518 #1: ffff88801523e460 (sb_writers#27){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2521 [inline] #1: ffff88801523e460 (sb_writers#27){.+.+}-{0:0}, at: btrfs_file_mmap+0x119/0x150 fs/btrfs/file.c:2333 stack backtrace: CPU: 1 PID: 9043 Comm: syz-executor.1 Not tainted 6.1.0-rc6-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 check_noncircular+0x25f/0x2e0 kernel/locking/lockdep.c:2177 check_prev_add kernel/locking/lockdep.c:3097 [inline] check_prevs_add kernel/locking/lockdep.c:3216 [inline] validate_chain kernel/locking/lockdep.c:3831 [inline] __lock_acquire+0x2a43/0x56d0 kernel/locking/lockdep.c:5055 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1e3/0x630 kernel/locking/lockdep.c:5633 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1826 [inline] sb_start_intwrite include/linux/fs.h:1948 [inline] start_transaction+0x878/0x1470 fs/btrfs/transaction.c:652 btrfs_dirty_inode+0xf4/0x250 fs/btrfs/inode.c:6085 btrfs_update_time+0x25a/0x2c0 fs/btrfs/inode.c:6127 inode_update_time fs/inode.c:1871 [inline] touch_atime+0x41f/0x700 fs/inode.c:1944 file_accessed include/linux/fs.h:2521 [inline] btrfs_file_mmap+0x119/0x150 fs/btrfs/file.c:2333 call_mmap include/linux/fs.h:2196 [inline] mmap_region+0x6c3/0x1dd0 mm/mmap.c:2625 do_mmap+0x831/0xf60 mm/mmap.c:1412 vm_mmap_pgoff+0x1af/0x280 mm/util.c:520 ksys_mmap_pgoff+0x41f/0x5a0 mm/mmap.c:1458 do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 do_fast_syscall_32+0x33/0x70 arch/x86/entry/common.c:203 entry_SYSENTER_compat_after_hwframe+0x70/0x82 RIP: 0023:0xf7ff9549 Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f7ff45cc EFLAGS: 00000296 ORIG_RAX: 00000000000000c0 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000b36000 RDX: 0000000000000002 RSI: 0000000000028011 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi 4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d a: 10 06 adc %al,(%rsi) c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 10: 10 07 adc %al,(%rdi) 12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi 16: 10 08 adc %cl,(%rax) 18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1c: 00 00 add %al,(%rax) 1e: 00 00 add %al,(%rax) 20: 00 51 52 add %dl,0x52(%rcx) 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 retq 2e: 90 nop 2f: 90 nop 30: 90 nop 31: 90 nop 32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi