======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/17546 is trying to acquire lock:
ffff88803fef50e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_free+0xc7/0x630 fs/hfsplus/bitmap.c:182

but task is already holding lock:
ffff88802b14d8b8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x2d0/0xd20 fs/hfsplus/extents.c:579

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
       hfsplus_get_block+0x391/0x1610 fs/hfsplus/extents.c:264
       block_read_full_folio+0x29f/0x810 fs/buffer.c:2308
       filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2520
       do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4156
       do_read_cache_page mm/filemap.c:4222 [inline]
       read_cache_page+0x5d/0x170 mm/filemap.c:4231
       read_mapping_page include/linux/pagemap.h:1009 [inline]
       hfsplus_block_allocate+0xf7/0xd30 fs/hfsplus/bitmap.c:37
       hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x41f/0x1610 fs/hfsplus/extents.c:249
       __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
       block_write_begin fs/buffer.c:2144 [inline]
       cont_write_begin+0x71b/0xac0 fs/buffer.c:2506
       hfsplus_write_begin+0x126/0x1e0 fs/hfsplus/inode.c:56
       cont_expand_zero fs/buffer.c:2434 [inline]
       cont_write_begin+0x2d6/0xac0 fs/buffer.c:2496
       hfsplus_write_begin+0x126/0x1e0 fs/hfsplus/inode.c:56
       generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4374
       generic_file_write_iter+0xaf/0x330 mm/filemap.c:4517
       new_sync_write fs/read_write.c:595 [inline]
       vfs_write+0x61e/0xbb0 fs/read_write.c:687
       ksys_pwrite64 fs/read_write.c:794 [inline]
       __do_sys_pwrite64 fs/read_write.c:802 [inline]
       __se_sys_pwrite64 fs/read_write.c:799 [inline]
       __x64_sys_pwrite64+0x199/0x230 fs/read_write.c:799
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&sbi->alloc_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
       __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
       hfsplus_block_free+0xc7/0x630 fs/hfsplus/bitmap.c:182
       hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:364
       hfsplus_file_truncate+0x7ef/0xd20 fs/hfsplus/extents.c:595
       hfsplus_delete_inode+0x180/0x230 fs/hfsplus/inode.c:-1
       hfsplus_unlink+0x4e4/0x8e0 fs/hfsplus/dir.c:420
       vfs_unlink+0x27b/0x6e0 fs/namei.c:5649
       filename_unlinkat+0x3d3/0x610 fs/namei.c:5719
       __do_sys_unlink fs/namei.c:5754 [inline]
       __se_sys_unlink+0x2e/0x140 fs/namei.c:5751
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&sbi->alloc_mutex);
                               lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&sbi->alloc_mutex);

 *** DEADLOCK ***

locks held by syz-executor/17546: 5, last CPU#0:
 #0: ffff888038484510 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:494
 #1: ffff88802b14a488 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1069 [inline]
 #1: ffff88802b14a488 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2918 [inline]
 #1: ffff88802b14a488 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2942 [inline]
 #1: ffff88802b14a488 (&type->i_mutex_dir_key#22/1){+.+.}-{4:4}, at: filename_unlinkat+0x2ad/0x610 fs/namei.c:5700
 #2: ffff88802b14da88 (&sb->s_type->i_mutex_key#45){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #2: ffff88802b14da88 (&sb->s_type->i_mutex_key#45){++++}-{4:4}, at: vfs_unlink+0xd5/0x6e0 fs/namei.c:5635
 #3: ffff88803fef5178 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_unlink+0x18b/0x8e0 fs/hfsplus/dir.c:385
 #4: ffff88802b14d8b8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_file_truncate+0x2d0/0xd20 fs/hfsplus/extents.c:579

stack backtrace:
CPU: 0 UID: 0 PID: 17546 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
 hfsplus_block_free+0xc7/0x630 fs/hfsplus/bitmap.c:182
 hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:364
 hfsplus_file_truncate+0x7ef/0xd20 fs/hfsplus/extents.c:595
 hfsplus_delete_inode+0x180/0x230 fs/hfsplus/inode.c:-1
 hfsplus_unlink+0x4e4/0x8e0 fs/hfsplus/dir.c:420
 vfs_unlink+0x27b/0x6e0 fs/namei.c:5649
 filename_unlinkat+0x3d3/0x610 fs/namei.c:5719
 __do_sys_unlink fs/namei.c:5754 [inline]
 __se_sys_unlink+0x2e/0x140 fs/namei.c:5751
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe16c1cd247
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fffde144e88 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe16c1cd247
RDX: 00007fffde144eb0 RSI: 00007fffde144f40 RDI: 00007fffde144f40
RBP: 00007fffde144f40 R08: 00007fffde145f40 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007fffde146030
R13: 00007fe16c2644bb R14: 0000000000104ad4 R15: 00007fffde147100
 </TASK>