====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc3-next-20220829 #1 Not tainted ------------------------------------------------------ syz-executor.4/11537 is trying to acquire lock: ffff88800c9a8400 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_bmap+0x4e/0x470 but task is already holding lock: ffff88801013a3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48b/0xc00 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: mutex_lock_io_nested+0x148/0x1310 jbd2_journal_flush+0x19a/0xc00 __ext4_ioctl+0x9e9/0x4090 __x64_sys_ioctl+0x19a/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #2 (&journal->j_barrier){+.+.}-{3:3}: __mutex_lock+0x136/0x14d0 jbd2_journal_lock_updates+0x15e/0x310 ext4_change_inode_journal_flag+0x17f/0x530 ext4_fileattr_set+0x140d/0x18a0 vfs_fileattr_set+0x77c/0xb80 do_vfs_ioctl+0xfc2/0x1610 __x64_sys_ioctl+0x10c/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #1 (&sbi->s_writepages_rwsem){++++}-{0:0}: percpu_down_write+0x4d/0x3d0 ext4_ind_migrate+0x237/0x830 ext4_fileattr_set+0x1434/0x18a0 vfs_fileattr_set+0x77c/0xb80 do_vfs_ioctl+0xfc2/0x1610 __x64_sys_ioctl+0x10c/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd -> #0 (&sb->s_type->i_mutex_key#6){++++}-{3:3}: __lock_acquire+0x2a02/0x5e70 lock_acquire+0x1a2/0x530 down_read+0x98/0x450 ext4_bmap+0x4e/0x470 bmap+0xac/0x120 jbd2_journal_bmap+0xa8/0x180 jbd2_journal_flush+0x853/0xc00 __ext4_ioctl+0x9e9/0x4090 __x64_sys_ioctl+0x19a/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &sb->s_type->i_mutex_key#6 --> &journal->j_barrier --> &journal->j_checkpoint_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&journal->j_checkpoint_mutex); lock(&journal->j_barrier); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#6); *** DEADLOCK *** 2 locks held by syz-executor.4/11537: #0: ffff88801013a170 (&journal->j_barrier){+.+.}-{3:3}, at: jbd2_journal_lock_updates+0x15e/0x310 #1: ffff88801013a3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: jbd2_journal_flush+0x48b/0xc00 stack backtrace: CPU: 0 PID: 11537 Comm: syz-executor.4 Not tainted 6.0.0-rc3-next-20220829 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: dump_stack_lvl+0x8b/0xb3 check_noncircular+0x263/0x2e0 __lock_acquire+0x2a02/0x5e70 lock_acquire+0x1a2/0x530 down_read+0x98/0x450 ext4_bmap+0x4e/0x470 bmap+0xac/0x120 jbd2_journal_bmap+0xa8/0x180 jbd2_journal_flush+0x853/0xc00 __ext4_ioctl+0x9e9/0x4090 __x64_sys_ioctl+0x19a/0x210 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fce2c9f7b19 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fce29f6d188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fce2cb0af60 RCX: 00007fce2c9f7b19 RDX: 0000000020000240 RSI: 000000004004662b RDI: 0000000000000006 RBP: 00007fce2ca51f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc03323b4f R14: 00007fce29f6d300 R15: 0000000000022000 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 9pnet_virtio: no channels available for device 127.0.0.1 device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode device lo left promiscuous mode device lo entered promiscuous mode random: crng reseeded on system resumption Restarting kernel threads ... done. random: crng reseeded on system resumption Restarting kernel threads ... done. random: crng reseeded on system resumption Restarting kernel threads ... done. random: crng reseeded on system resumption Restarting kernel threads ... done. random: crng reseeded on system resumption Restarting kernel threads ... done.