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
5.15.169-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor203/4302 is trying to acquire lock:
ffff888022f11488 (&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:
ffff88806d82ea20 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_write_begin+0x1cb/0x390 fs/ocfs2/aops.c:1903

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+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       down_read+0x45/0x2e0 kernel/locking/rwsem.c:1498
       ocfs2_read_virt_blocks+0x2b3/0xa10 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+0x437/0x26d0 fs/ocfs2/dir.c:1080
       ocfs2_find_files_on_disk+0xea/0x310 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:458
       ocfs2_initialize_super fs/ocfs2/super.c:2276 [inline]
       ocfs2_fill_super+0x479e/0x58a0 fs/ocfs2/super.c:995
       mount_bdev+0x2c9/0x3f0 fs/super.c:1400
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:611
       vfs_get_tree+0x88/0x270 fs/super.c:1530
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3012
       do_mount fs/namespace.c:3355 [inline]
       __do_sys_mount fs/namespace.c:3563 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3540
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1da/0x25a0 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+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_local_alloc_bits+0x103/0x27a0 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+0x28e5/0x4d20 fs/ocfs2/aops.c:1741
       ocfs2_write_begin+0x1fd/0x390 fs/ocfs2/aops.c:1905
       generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
       __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
       ocfs2_file_write_iter+0x17d5/0x1fa0 fs/ocfs2/file.c:2459
       call_write_iter include/linux/fs.h:2174 [inline]
       new_sync_write fs/read_write.c:507 [inline]
       vfs_write+0xacd/0xe50 fs/read_write.c:594
       ksys_write+0x1a2/0x2c0 fs/read_write.c:647
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 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-executor203/4302:
 #0: ffff88807720a460 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x29a/0xe50 fs/read_write.c:590
 #1: ffff88806d82ed88 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
 #1: ffff88806d82ed88 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: ocfs2_file_write_iter+0x446/0x1fa0 fs/ocfs2/file.c:2391
 #2: ffff88806d82ea20 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}, at: ocfs2_write_begin+0x1cb/0x390 fs/ocfs2/aops.c:1903

stack backtrace:
CPU: 1 PID: 4302 Comm: syz-executor203 Not tainted 5.15.169-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+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 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+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1da/0x25a0 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+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101
 ocfs2_reserve_local_alloc_bits+0x103/0x27a0 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+0x28e5/0x4d20 fs/ocfs2/aops.c:1741
 ocfs2_write_begin+0x1fd/0x390 fs/ocfs2/aops.c:1905
 generic_perform_write+0x2bf/0x5b0 mm/filemap.c:3785
 __generic_file_write_iter+0x243/0x4f0 mm/filemap.c:3912
 ocfs2_file_write_iter+0x17d5/0x1fa0 fs/ocfs2/file.c:2459
 call_write_iter include/linux/fs.h:2174 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0xacd/0xe50 fs/read_write.c:594
 ksys_write+0x1a2/0x2c0 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd7f1b1c169
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:00007ffed3528fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd7f1b1c169
RDX: 000000000000fd14 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 0000000000000004 R08: 00000000010008d0 R09: 00000000010008d0
R10: 000000000000442c R11: 0000000000000246 R12: 00007ffed3528ff0
R13: 00007ffed3529030 R14: 0000000001000000 R15: 0000000000000003
 </TASK>