9pnet_virtio: no channels available for device syz ====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc8-next-20230214 #1 Not tainted ------------------------------------------------------ rs:main Q:Reg/168 is trying to acquire lock: ffff88800ff8c3f8 (&journal->j_checkpoint_mutex){+.+.}-{3:3}, at: __jbd2_log_wait_for_space+0x238/0x4b0 but task is already holding lock: ffff88801969dd70 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_buffered_write_iter+0xb0/0x460 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#6){++++}-{3:3}: down_read+0x3d/0x50 ext4_bmap+0x52/0x470 bmap+0xb0/0x130 jbd2_journal_bmap+0xac/0x1d0 jbd2_journal_flush+0x87f/0xc90 __ext4_ioctl+0x9fd/0x4330 __x64_sys_ioctl+0x19e/0x210 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc -> #0 (&journal->j_checkpoint_mutex){+.+.}-{3:3}: __lock_acquire+0x2da7/0x63b0 lock_acquire.part.0+0xec/0x320 mutex_lock_io_nested+0x149/0x1300 __jbd2_log_wait_for_space+0x238/0x4b0 add_transaction_credits+0xa42/0xb80 start_this_handle+0x3a6/0x14d0 jbd2__journal_start+0x394/0x6b0 __ext4_journal_start_sb+0x4c2/0x6f0 ext4_dirty_inode+0xa5/0x130 __mark_inode_dirty+0x1aa/0xee0 generic_write_end+0x319/0x3d0 ext4_da_write_end+0x162/0x950 generic_perform_write+0x318/0x580 ext4_buffered_write_iter+0x164/0x460 ext4_file_write_iter+0x3ff/0x1930 vfs_write+0x9b4/0xdc0 ksys_write+0x12b/0x260 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sb->s_type->i_mutex_key#6); lock(&journal->j_checkpoint_mutex); lock(&sb->s_type->i_mutex_key#6); lock(&journal->j_checkpoint_mutex); *** DEADLOCK *** 3 locks held by rs:main Q:Reg/168: #0: ffff88800e548ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xeb/0x110 #1: ffff88800ff88438 (sb_writers#3){.+.+}-{0:0}, at: ksys_write+0x12b/0x260 #2: ffff88801969dd70 (&sb->s_type->i_mutex_key#6){++++}-{3:3}, at: ext4_buffered_write_iter+0xb0/0x460 stack backtrace: CPU: 0 PID: 168 Comm: rs:main Q:Reg Not tainted 6.2.0-rc8-next-20230214 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x91/0xf0 check_noncircular+0x263/0x2e0 __lock_acquire+0x2da7/0x63b0 lock_acquire.part.0+0xec/0x320 mutex_lock_io_nested+0x149/0x1300 __jbd2_log_wait_for_space+0x238/0x4b0 add_transaction_credits+0xa42/0xb80 start_this_handle+0x3a6/0x14d0 jbd2__journal_start+0x394/0x6b0 __ext4_journal_start_sb+0x4c2/0x6f0 ext4_dirty_inode+0xa5/0x130 __mark_inode_dirty+0x1aa/0xee0 generic_write_end+0x319/0x3d0 ext4_da_write_end+0x162/0x950 generic_perform_write+0x318/0x580 ext4_buffered_write_iter+0x164/0x460 ext4_file_write_iter+0x3ff/0x1930 vfs_write+0x9b4/0xdc0 ksys_write+0x12b/0x260 do_syscall_64+0x3f/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7ff232ec8fef Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 5c fd ff ff 48 RSP: 002b:00007ff232084860 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff228022330 RCX: 00007ff232ec8fef RDX: 0000000000000064 RSI: 00007ff2280225d0 RDI: 0000000000000007 RBP: 0000000000000064 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007ff2280225d0 R13: 0000000000000000 R14: 0000000000000064 R15: 00007ff228022330 9pnet_virtio: no channels available for device syz 9pnet_virtio: no channels available for device syz audit: type=1326 audit(1676374087.345:30): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=10018 comm="syz-executor.0" exe="/syz-executor.0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fcb8a4f5b19 code=0x0 audit: type=1326 audit(1676374088.179:31): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=10018 comm="syz-executor.0" exe="/syz-executor.0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fcb8a4f5b19 code=0x0 audit: type=1326 audit(1676374088.422:32): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=10054 comm="syz-executor.0" exe="/syz-executor.0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fcb8a4f5b19 code=0x0 audit: type=1326 audit(1676374089.645:33): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=10095 comm="syz-executor.0" exe="/syz-executor.0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fcb8a4f5b19 code=0x0 audit: type=1326 audit(1676374090.840:34): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=10127 comm="syz-executor.0" exe="/syz-executor.0" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fcb8a4f5b19 code=0x0