syzbot

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.28/4352 is trying to acquire lock:
ffff888024f1d488 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x1a4/0x7f0 fs/ocfs2/sysfile.c:101

but task is already holding lock:
ffff88806df80660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_dio_wr_get_block+0x90c/0x1810 fs/ocfs2/aops.c:2227

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
       down_read+0x44/0x2e0 kernel/locking/rwsem.c:1498
       ocfs2_read_virt_blocks+0x240/0x8e0 fs/ocfs2/extent_map.c:984
       ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline]
       ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
       ocfs2_find_entry+0x39d/0x1f90 fs/ocfs2/dir.c:1091
       ocfs2_find_files_on_disk+0xdb/0x2f0 fs/ocfs2/dir.c:1995
       ocfs2_lookup_ino_from_name+0x4f/0xf0 fs/ocfs2/dir.c:2017
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x33f/0x7f0 fs/ocfs2/sysfile.c:112
       ocfs2_init_global_system_inodes+0x315/0x6e0 fs/ocfs2/super.c:458
       ocfs2_initialize_super fs/ocfs2/super.c:2279 [inline]
       ocfs2_fill_super+0x4032/0x50c0 fs/ocfs2/super.c:995
       mount_bdev+0x28a/0x3c0 fs/super.c:1400
       legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x247/0xa40 fs/namespace.c:3034
       do_mount fs/namespace.c:3377 [inline]
       __do_sys_mount fs/namespace.c:3585 [inline]
       __se_sys_mount+0x2e3/0x3d0 fs/namespace.c:3562
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&osb->system_file_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
       lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
       ocfs2_get_system_file_inode+0x1a4/0x7f0 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_local_alloc_bits+0xfb/0x2630 fs/ocfs2/localalloc.c:626
       ocfs2_reserve_clusters_with_limit+0x1b6/0xc10 fs/ocfs2/suballoc.c:1184
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1245 [inline]
       ocfs2_lock_allocators+0x2ce/0x5f0 fs/ocfs2/suballoc.c:2701
       ocfs2_write_begin_nolock+0x1b97/0x44b0 fs/ocfs2/aops.c:1743
       ocfs2_dio_wr_get_block+0xba4/0x1810 fs/ocfs2/aops.c:2241
       get_more_blocks fs/direct-io.c:673 [inline]
       do_direct_IO fs/direct-io.c:959 [inline]
       do_blockdev_direct_IO fs/direct-io.c:1276 [inline]
       __blockdev_direct_IO+0x142d/0x3b20 fs/direct-io.c:1368
       ocfs2_direct_IO+0x233/0x2a0 fs/ocfs2/aops.c:2483
       generic_file_direct_write+0x222/0x470 mm/filemap.c:3687
       __generic_file_write_iter+0x2b2/0x4e0 mm/filemap.c:3869
       ocfs2_file_write_iter+0x171a/0x1ee0 fs/ocfs2/file.c:2472
       do_iter_readv_writev+0x47d/0x5f0 fs/read_write.c:-1
       do_iter_write+0x1f8/0x7a0 fs/read_write.c:855
       iter_file_splice_write+0x6be/0xcf0 fs/splice.c:689
       do_splice_from fs/splice.c:767 [inline]
       direct_splice_actor+0xe1/0x130 fs/splice.c:956
       splice_direct_to_actor+0x4e8/0xc00 fs/splice.c:902
       do_splice_direct+0x1d4/0x2f0 fs/splice.c:1008
       do_sendfile+0x524/0xe30 fs/read_write.c:1249
       __do_sys_sendfile64 fs/read_write.c:1317 [inline]
       __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1303
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ocfs2_file_ip_alloc_sem_key);
                               lock(&osb->system_file_mutex);
                               lock(&ocfs2_file_ip_alloc_sem_key);
  lock(&osb->system_file_mutex);

 *** DEADLOCK ***

3 locks held by syz.0.28/4352:
 #0: ffff88807aee4460 (sb_writers#13){.+.+}-{0:0}, at: do_sendfile+0x4ff/0xe30 fs/read_write.c:1248
 #1: ffff88806df809c8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
 #1: ffff88806df809c8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x437/0x1ee0 fs/ocfs2/file.c:2402
 #2: ffff88806df80660 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_dio_wr_get_block+0x90c/0x1810 fs/ocfs2/aops.c:2227

stack backtrace:
CPU: 1 PID: 4352 Comm: syz.0.28 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c66/0x7b50 kernel/locking/lockdep.c:5012
 lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1e5/0x2400 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 ocfs2_get_system_file_inode+0x1a4/0x7f0 fs/ocfs2/sysfile.c:101
 ocfs2_reserve_local_alloc_bits+0xfb/0x2630 fs/ocfs2/localalloc.c:626
 ocfs2_reserve_clusters_with_limit+0x1b6/0xc10 fs/ocfs2/suballoc.c:1184
 ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1245 [inline]
 ocfs2_lock_allocators+0x2ce/0x5f0 fs/ocfs2/suballoc.c:2701
 ocfs2_write_begin_nolock+0x1b97/0x44b0 fs/ocfs2/aops.c:1743
 ocfs2_dio_wr_get_block+0xba4/0x1810 fs/ocfs2/aops.c:2241
 get_more_blocks fs/direct-io.c:673 [inline]
 do_direct_IO fs/direct-io.c:959 [inline]
 do_blockdev_direct_IO fs/direct-io.c:1276 [inline]
 __blockdev_direct_IO+0x142d/0x3b20 fs/direct-io.c:1368
 ocfs2_direct_IO+0x233/0x2a0 fs/ocfs2/aops.c:2483
 generic_file_direct_write+0x222/0x470 mm/filemap.c:3687
 __generic_file_write_iter+0x2b2/0x4e0 mm/filemap.c:3869
 ocfs2_file_write_iter+0x171a/0x1ee0 fs/ocfs2/file.c:2472
 do_iter_readv_writev+0x47d/0x5f0 fs/read_write.c:-1
 do_iter_write+0x1f8/0x7a0 fs/read_write.c:855
 iter_file_splice_write+0x6be/0xcf0 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0xe1/0x130 fs/splice.c:956
 splice_direct_to_actor+0x4e8/0xc00 fs/splice.c:902
 do_splice_direct+0x1d4/0x2f0 fs/splice.c:1008
 do_sendfile+0x524/0xe30 fs/read_write.c:1249
 __do_sys_sendfile64 fs/read_write.c:1317 [inline]
 __se_sys_sendfile64+0x141/0x1a0 fs/read_write.c:1303
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f00ad24be99
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcb01d0b98 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f00ad4d3fa0 RCX: 00007f00ad24be99
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00007f00ad2e1eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000fffe82 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00ad4d3fac R14: 00007f00ad4d3fa0 R15: 00007f00ad4d3fa0
 </TASK>
(syz.0.28,4352,1):ocfs2_dio_end_io:2443 ERROR: Direct IO failed, bytes = -5