syzbot

loop0: detected capacity change from 0 to 32768
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.
======================================================
WARNING: possible circular locking dependency detected
6.1.114-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor154/4390 is trying to acquire lock:
ffff888075615488 (&osb->system_file_mutex){+.+.}-{3:3}, at: ocfs2_get_system_file_inode+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101

but task is already holding lock:
ffff88806d4422e0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_write_begin+0x1cd/0x390 fs/ocfs2/aops.c:1902

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}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ocfs2_read_virt_blocks+0x2dc/0xab0 fs/ocfs2/extent_map.c:976
       ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline]
       ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
       ocfs2_find_entry+0x436/0x28c0 fs/ocfs2/dir.c:1080
       ocfs2_find_files_on_disk+0x10d/0x3a0 fs/ocfs2/dir.c:1982
       ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2004
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x314/0x7b0 fs/ocfs2/sysfile.c:112
       ocfs2_init_global_system_inodes+0x328/0x720 fs/ocfs2/super.c:457
       ocfs2_initialize_super fs/ocfs2/super.c:2250 [inline]
       ocfs2_fill_super+0x2f82/0x5730 fs/ocfs2/super.c:994
       mount_bdev+0x2c9/0x3f0 fs/super.c:1443
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3056
       do_mount fs/namespace.c:3399 [inline]
       __do_sys_mount fs/namespace.c:3607 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3584
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&osb->system_file_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       ocfs2_get_system_file_inode+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_local_alloc_bits+0xfe/0x29d0 fs/ocfs2/localalloc.c:626
       ocfs2_reserve_clusters_with_limit+0x1b4/0xb50 fs/ocfs2/suballoc.c:1162
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
       ocfs2_lock_allocators+0x306/0x620 fs/ocfs2/suballoc.c:2669
       ocfs2_write_begin_nolock+0x271a/0x4e40 fs/ocfs2/aops.c:1740
       ocfs2_write_begin+0x201/0x390 fs/ocfs2/aops.c:1904
       generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
       __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
       ocfs2_file_write_iter+0x17c6/0x2020 fs/ocfs2/file.c:2456
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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-executor154/4390:
 #0: ffff888030a32460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #1: ffff88806d442648 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #1: ffff88806d442648 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x476/0x2020 fs/ocfs2/file.c:2388
 #2: ffff88806d4422e0 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_write_begin+0x1cd/0x390 fs/ocfs2/aops.c:1902

stack backtrace:
CPU: 1 PID: 4390 Comm: syz-executor154 Not tainted 6.1.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
 ocfs2_get_system_file_inode+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101
 ocfs2_reserve_local_alloc_bits+0xfe/0x29d0 fs/ocfs2/localalloc.c:626
 ocfs2_reserve_clusters_with_limit+0x1b4/0xb50 fs/ocfs2/suballoc.c:1162
 ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
 ocfs2_lock_allocators+0x306/0x620 fs/ocfs2/suballoc.c:2669
 ocfs2_write_begin_nolock+0x271a/0x4e40 fs/ocfs2/aops.c:1740
 ocfs2_write_begin+0x201/0x390 fs/ocfs2/aops.c:1904
 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
 ocfs2_file_write_iter+0x17c6/0x2020 fs/ocfs2/file.c:2456
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff8d9846329
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffa25e1308 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007ff8d9846329
RDX: 0000000000000078 RSI: 0000000020000340 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fffa25e1340 R09: 00007fffa25e1340
R10: 00007fffa25e1340 R11: 0000000000000246 R12: 00007fffa25e132c
R13: 0000000000000031 R14: 431bde82d7b634db R15: 00007fffa25e1360
 </TASK>