====================================================== WARNING: possible circular locking dependency detected 4.14.0-rc3-mm1+ #14 Not tainted ------------------------------------------------------ loop0/10930 is trying to acquire lock: (&sb->s_type->i_mutex_key#9){++++}, at: [] inode_lock include/linux/fs.h:712 [inline] (&sb->s_type->i_mutex_key#9){++++}, at: [] generic_file_write_iter+0xdc/0x7a0 mm/filemap.c:3175 but now in release context of a crosslock acquired at the following: ((complete)&ret.event){+.+.}, at: [] submit_bio_wait+0x15e/0x200 block/bio.c:953 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 ((complete)&ret.event){+.+.}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 complete_acquire include/linux/completion.h:39 [inline] __wait_for_common kernel/sched/completion.c:108 [inline] wait_for_common_io kernel/sched/completion.c:128 [inline] wait_for_completion_io+0xcb/0x7b0 kernel/sched/completion.c:176 submit_bio_wait+0x15e/0x200 block/bio.c:953 blkdev_issue_zeroout+0x13c/0x1d0 block/blk-lib.c:370 sb_issue_zeroout include/linux/blkdev.h:1368 [inline] ext4_init_inode_table+0x4fd/0xdb1 fs/ext4/ialloc.c:1447 ext4_run_li_request fs/ext4/super.c:2868 [inline] ext4_lazyinit_thread+0x808/0xd30 fs/ext4/super.c:2962 kthread+0x3c9/0x4b0 kernel/kthread.c:242 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 -> #3 (&meta_group_info[i]->alloc_sem){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 down_read+0x96/0x150 kernel/locking/rwsem.c:23 __ext4_new_inode+0x26dc/0x4f00 fs/ext4/ialloc.c:1056 ext4_symlink+0x2d9/0xae0 fs/ext4/namei.c:3118 vfs_symlink+0x323/0x560 fs/namei.c:4115 SYSC_symlinkat fs/namei.c:4142 [inline] SyS_symlinkat fs/namei.c:4122 [inline] SYSC_symlink fs/namei.c:4155 [inline] SyS_symlink+0x134/0x200 fs/namei.c:4153 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #2 (jbd2_handle){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 start_this_handle+0x4b8/0x1080 fs/jbd2/transaction.c:390 jbd2__journal_start+0x389/0x9f0 fs/jbd2/transaction.c:444 __ext4_journal_start_sb+0x15f/0x550 fs/ext4/ext4_jbd2.c:80 __ext4_journal_start fs/ext4/ext4_jbd2.h:314 [inline] ext4_dirty_inode+0x56/0xa0 fs/ext4/inode.c:5859 __mark_inode_dirty+0x912/0x1170 fs/fs-writeback.c:2096 generic_update_time+0x1b2/0x270 fs/inode.c:1649 update_time fs/inode.c:1665 [inline] touch_atime+0x26d/0x2f0 fs/inode.c:1737 file_accessed include/linux/fs.h:2061 [inline] ext4_file_mmap+0x161/0x1b0 fs/ext4/file.c:352 call_mmap include/linux/fs.h:1775 [inline] mmap_region+0xa99/0x15a0 mm/mmap.c:1690 do_mmap+0x6a1/0xd50 mm/mmap.c:1468 do_mmap_pgoff include/linux/mm.h:2180 [inline] vm_mmap_pgoff+0x1de/0x280 mm/util.c:333 SYSC_mmap_pgoff mm/mmap.c:1518 [inline] SyS_mmap_pgoff+0x462/0x5f0 mm/mmap.c:1476 SYSC_mmap arch/x86/kernel/sys_x86_64.c:99 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:90 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #1 (&mm->mmap_sem){++++}: check_prevs_add kernel/locking/lockdep.c:2020 [inline] validate_chain kernel/locking/lockdep.c:2469 [inline] __lock_acquire+0x328f/0x4620 kernel/locking/lockdep.c:3498 lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4002 __might_fault+0x13a/0x1d0 mm/memory.c:4525 _copy_to_user+0x2c/0xc0 lib/usercopy.c:24 copy_to_user include/linux/uaccess.h:154 [inline] filldir+0x1a7/0x320 fs/readdir.c:196 dir_emit_dot include/linux/fs.h:3341 [inline] dir_emit_dots include/linux/fs.h:3352 [inline] dcache_readdir+0x12d/0x5e0 fs/libfs.c:193 iterate_dir+0x4b2/0x5d0 fs/readdir.c:51 SYSC_getdents fs/readdir.c:231 [inline] SyS_getdents+0x225/0x450 fs/readdir.c:212 entry_SYSCALL_64_fastpath+0x1f/0xbe -> #0 (&sb->s_type->i_mutex_key#9){++++}: down_write+0x87/0x120 kernel/locking/rwsem.c:53 inode_lock include/linux/fs.h:712 [inline] generic_file_write_iter+0xdc/0x7a0 mm/filemap.c:3175 call_write_iter include/linux/fs.h:1770 [inline] do_iter_readv_writev+0x531/0x7f0 fs/read_write.c:673 do_iter_write+0x15a/0x540 fs/read_write.c:952 vfs_iter_write+0x77/0xb0 fs/read_write.c:965 other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#9 --> &meta_group_info[i]->alloc_sem --> (complete)&ret.event Possible unsafe locking scenario by crosslock: CPU0 CPU1 ---- ---- lock(&meta_group_info[i]->alloc_sem); lock((complete)&ret.event); lock(&sb->s_type->i_mutex_key#9); unlock((complete)&ret.event); *** DEADLOCK *** 1 lock held by loop0/10930: #0: (&x->wait#14){..-.}, at: [] complete+0x18/0x80 kernel/sched/completion.c:34 stack backtrace: CPU: 1 PID: 10930 Comm: loop0 Not tainted 4.14.0-rc3-mm1+ #14 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 print_circular_bug+0x503/0x710 kernel/locking/lockdep.c:1259 check_prev_add+0x865/0x1520 kernel/locking/lockdep.c:1894 commit_xhlock kernel/locking/lockdep.c:5015 [inline] commit_xhlocks kernel/locking/lockdep.c:5059 [inline] lock_commit_crosslock+0xe59/0x1d00 kernel/locking/lockdep.c:5098 complete_release_commit include/linux/completion.h:49 [inline] complete+0x24/0x80 kernel/sched/completion.c:39 submit_bio_wait_endio+0x9c/0xd0 block/bio.c:930 bio_endio+0x2f8/0x8d0 block/bio.c:1843 req_bio_endio block/blk-core.c:204 [inline] blk_update_request+0x2a6/0xe20 block/blk-core.c:2746 blk_mq_end_request+0x54/0x120 block/blk-mq.c:509 lo_complete_rq+0xbe/0x1f0 drivers/block/loop.c:463 __blk_mq_complete_request+0x38f/0x6c0 block/blk-mq.c:550 blk_mq_complete_request+0x4f/0x60 block/blk-mq.c:570 loop_handle_cmd drivers/block/loop.c:1723 [inline] loop_queue_work+0x26b/0x3900 drivers/block/loop.c:1732 kthread_worker_fn+0x32b/0x980 kernel/kthread.c:646 loop_kthread_worker_fn+0x51/0x60 drivers/block/loop.c:841 kthread+0x3c9/0x4b0 kernel/kthread.c:242 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431 sctp: [Deprecated]: syz-executor6 (pid 14519) Use of int in max_burst socket option. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor6 (pid 14507) Use of int in max_burst socket option. Use struct sctp_assoc_value instead rfkill: input handler disabled rfkill: input handler enabled QAT: Invalid ioctl QAT: Invalid ioctl audit: type=1326 audit(1507463011.067:174): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=14475 comm="syz-executor2" exe="/root/syz-executor2" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 QAT: Invalid ioctl kvm [14709]: vcpu2, guest rIP: 0xfff0 Hyper-V uhandled wrmsr: 0x40000020 data 0x4 QAT: Invalid ioctl kvm [14709]: vcpu2, guest rIP: 0xfff0 Hyper-V uhandled wrmsr: 0x40000020 data 0x4 QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. audit: type=1326 audit(1507463012.552:175): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=14750 comm="syz-executor6" exe="/root/syz-executor6" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. device lo entered promiscuous mode TCP: request_sock_TCP: Possible SYN flooding on port 20004. Sending cookies. Check SNMP counters. selinux_nlmsg_perm: 2 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=22539 sclass=netlink_route_socket pig=14939 comm=syz-executor0 QAT: Invalid ioctl QAT: Invalid ioctl 9pnet_virtio: no channels available for device ./file0 9pnet_virtio: no channels available for device ./file0 : port 1(syz5) entered blocking state : port 1(syz5) entered disabled state device syz5 entered promiscuous mode netlink: 5 bytes leftover after parsing attributes in process `syz-executor4'. QAT: Invalid ioctl sctp: [Deprecated]: syz-executor2 (pid 15330) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor2 (pid 15330) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead QAT: Invalid ioctl netlink: 3 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 4 bytes leftover after parsing attributes in process `syz-executor0'. QAT: Invalid ioctl QAT: Invalid ioctl SELinux: unrecognized netlink message: protocol=9 nlmsg_type=19 sclass=netlink_audit_socket pig=15502 comm=syz-executor3 SELinux: unrecognized netlink message: protocol=9 nlmsg_type=19 sclass=netlink_audit_socket pig=15502 comm=syz-executor3 syz6: Invalid MTU 3 requested, hw min 68 syz6: Invalid MTU 3 requested, hw min 68 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=3 sclass=netlink_route_socket pig=15535 comm=syz-executor0 nla_parse: 2 callbacks suppressed netlink: 29 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 29 bytes leftover after parsing attributes in process `syz-executor5'. SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=15544 comm=syz-executor0 netlink: 1 bytes leftover after parsing attributes in process `syz-executor5'. SELinux: unrecognized netlink message: protocol=9 nlmsg_type=28 sclass=netlink_audit_socket pig=15533 comm=syz-executor7 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=15544 comm=syz-executor0 SELinux: unrecognized netlink message: protocol=9 nlmsg_type=28 sclass=netlink_audit_socket pig=15551 comm=syz-executor7 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=3 sclass=netlink_route_socket pig=15544 comm=syz-executor0 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=0 sclass=netlink_route_socket pig=15544 comm=syz-executor0 netlink: 5 bytes leftover after parsing attributes in process `syz-executor6'. IPv6: Can't replace route, no match found netlink: 58 bytes leftover after parsing attributes in process `syz-executor6'. do_dccp_getsockopt: sockopt(PACKET_SIZE) is deprecated: fix your app netlink: 5 bytes leftover after parsing attributes in process `syz-executor6'. IPv6: Can't replace route, no match found netlink: 58 bytes leftover after parsing attributes in process `syz-executor6'. rfkill: input handler disabled do_dccp_getsockopt: sockopt(PACKET_SIZE) is deprecated: fix your app rfkill: input handler enabled netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor0'. audit: type=1326 audit(1507463015.755:176): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=15751 comm="syz-executor7" exe="/root/syz-executor7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 audit: type=1326 audit(1507463015.777:177): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=15751 comm="syz-executor7" exe="/root/syz-executor7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 device syz6 entered promiscuous mode device syz6 left promiscuous mode device syz6 entered promiscuous mode audit: type=1326 audit(1507463017.404:178): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16156 comm="syz-executor7" exe="/root/syz-executor7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 audit: type=1326 audit(1507463017.486:179): auid=4294967295 uid=0 gid=0 ses=4294967295 subj=kernel pid=16156 comm="syz-executor7" exe="/root/syz-executor7" sig=31 arch=c000003e syscall=202 compat=0 ip=0x4520a9 code=0xffff0000 QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl selinux_nlmsg_perm: 7 callbacks suppressed SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=16327 comm=syz-executor4 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=45445 sclass=netlink_route_socket pig=16339 comm=syz-executor4 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=43 sclass=netlink_route_socket pig=16327 comm=syz-executor4 SELinux: unrecognized netlink message: protocol=0 nlmsg_type=45445 sclass=netlink_route_socket pig=16327 comm=syz-executor4 device syz6 left promiscuous mode QAT: Invalid ioctl IPv6: ADDRCONF(NETDEV_CHANGE): syz6: link becomes ready QAT: Invalid ioctl IPv6: ADDRCONF(NETDEV_CHANGE): syz6: link becomes ready rfkill: input handler disabled IPv6: ADDRCONF(NETDEV_CHANGE): syz6: link becomes ready tmpfs: No value for mount option 'I' tmpfs: No value for mount option 'I' rfkill: input handler enabled SELinux: unrecognized netlink message: protocol=4 nlmsg_type=24 sclass=netlink_tcpdiag_socket pig=16539 comm=proc; RDS: rds_bind could not find a transport for 0.0.0.145, load rds_tcp or rds_rdma? SELinux: unrecognized netlink message: protocol=4 nlmsg_type=24 sclass=netlink_tcpdiag_socket pig=16552 comm=proc; sctp: [Deprecated]: syz-executor3 (pid 16746) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead sctp: [Deprecated]: syz-executor3 (pid 16770) Use of int in max_burst socket option deprecated. Use struct sctp_assoc_value instead loop_reread_partitions: partition scan of loop0 (-\t@r9hxGQ:[il L*@R-Tr-x) failed (rc=-13) xs_tcp_setup_socket: connect returned unhandled error -113 xprt_adjust_timeout: rq_timeout = 0! xs_tcp_setup_socket: connect returned unhandled error -113 xprt_adjust_timeout: rq_timeout = 0! nla_parse: 17 callbacks suppressed netlink: 1 bytes leftover after parsing attributes in process `syz-executor7'. 9pnet_virtio: no channels available for device ./bus IPv6: NLM_F_REPLACE set, but no existing node found! netlink: 1 bytes leftover after parsing attributes in process `syz-executor0'. 9pnet_virtio: no channels available for device ./bus netlink: 1 bytes leftover after parsing attributes in process `syz-executor0'. netlink: 1 bytes leftover after parsing attributes in process `syz-executor7'. IPv6: NLM_F_REPLACE set, but no existing node found! netlink: 2 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 2 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 5 bytes leftover after parsing attributes in process `syz-executor3'. netlink: 3 bytes leftover after parsing attributes in process `syz-executor5'. dccp_close: ABORT with 182 bytes unread QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl QAT: Invalid ioctl device syz6 entered promiscuous mode device syz6 left promiscuous mode device syz6 entered promiscuous mode