syzbot

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.0/5360 is trying to acquire lock:
ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_try_to_free_truncate_log+0xaf/0x360 fs/ocfs2/alloc.c:6132

but task is already holding lock:
ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_defrag_extent fs/ocfs2/move_extents.c:253 [inline]
ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: __ocfs2_move_extents_range fs/ocfs2/move_extents.c:862 [inline]
ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_move_extents+0x160b/0x3dd0 fs/ocfs2/move_extents.c:937

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);
  lock(&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

5 locks held by syz.0.0/5360:
 #0: ffff888040564420 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x60/0x200 fs/namespace.c:543
 #1: ffff888037f2c2c0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #1: ffff888037f2c2c0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: ocfs2_move_extents+0x1fb/0x3dd0 fs/ocfs2/move_extents.c:915
 #2: ffff888037f2bf60 (&oi->ip_alloc_sem){++++}-{4:4}, at: ocfs2_move_extents+0x3b3/0x3dd0 fs/ocfs2/move_extents.c:935
 #3: ffff888037f36d80 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #3: ffff888037f36d80 (&ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_reserve_suballoc_bits+0x164/0x4600 fs/ocfs2/suballoc.c:789
 #4: ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #4: ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_defrag_extent fs/ocfs2/move_extents.c:253 [inline]
 #4: ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: __ocfs2_move_extents_range fs/ocfs2/move_extents.c:862 [inline]
 #4: ffff888037f2b480 (&ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]){+.+.}-{4:4}, at: ocfs2_move_extents+0x160b/0x3dd0 fs/ocfs2/move_extents.c:937

stack backtrace:
CPU: 0 UID: 0 PID: 5360 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_deadlock_bug+0x279/0x290 kernel/locking/lockdep.c:3041
 check_deadlock kernel/locking/lockdep.c:3093 [inline]
 validate_chain kernel/locking/lockdep.c:3895 [inline]
 __lock_acquire+0x2540/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590
 inode_lock include/linux/fs.h:1027 [inline]
 ocfs2_try_to_free_truncate_log+0xaf/0x360 fs/ocfs2/alloc.c:6132
 ocfs2_reserve_clusters_with_limit+0x3c2/0xba0 fs/ocfs2/suballoc.c:1187
 ocfs2_defrag_extent fs/ocfs2/move_extents.c:272 [inline]
 __ocfs2_move_extents_range fs/ocfs2/move_extents.c:862 [inline]
 ocfs2_move_extents+0x196d/0x3dd0 fs/ocfs2/move_extents.c:937
 ocfs2_ioctl_move_extents+0x568/0x740 fs/ocfs2/move_extents.c:1069
 ocfs2_ioctl+0x191/0x750 fs/ocfs2/ioctl.c:942
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7f4938f7c9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7f4a157038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7f495e6180 RCX: 00007f7f4938f7c9
RDX: 00002000000000c0 RSI: 0000000040406f06 RDI: 0000000000000004
RBP: 00007f7f49413f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7f495e6218 R14: 00007f7f495e6180 R15: 00007ffc2ffc60b8
 </TASK>