loop1: detected capacity change from 0 to 1024
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.97/6508 is trying to acquire lock:
ffff88802c0b69f8 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x39a/0x1600 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff888027cb28e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xd10 fs/hfsplus/bitmap.c:35

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sbi->alloc_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
       hfsplus_block_free+0xc7/0x630 fs/hfsplus/bitmap.c:182
       hfsplus_free_extents+0x121/0xa50 fs/hfsplus/extents.c:360
       hfsplus_file_truncate+0x751/0xc10 fs/hfsplus/extents.c:588
       hfsplus_delete_inode+0x180/0x230 fs/hfsplus/inode.c:-1
       hfsplus_unlink+0x4e6/0x740 fs/hfsplus/dir.c:405
       vfs_unlink+0x386/0x650 fs/namei.c:5369
       do_unlinkat+0x2cf/0x570 fs/namei.c:5439
       __do_sys_unlink fs/namei.c:5474 [inline]
       __se_sys_unlink fs/namei.c:5472 [inline]
       __x64_sys_unlink+0x47/0x50 fs/namei.c:5472
       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

-> #0 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
       __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
       hfsplus_get_block+0x39a/0x1600 fs/hfsplus/extents.c:260
       block_read_full_folio+0x29f/0x830 fs/buffer.c:2420
       filemap_read_folio+0x117/0x380 mm/filemap.c:2496
       do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4096
       do_read_cache_page mm/filemap.c:4162 [inline]
       read_cache_page+0x5d/0x170 mm/filemap.c:4171
       read_mapping_page include/linux/pagemap.h:1011 [inline]
       hfsplus_block_allocate+0xf3/0xd10 fs/hfsplus/bitmap.c:37
       hfsplus_file_extend+0xa9a/0x1c40 fs/hfsplus/extents.c:464
       hfsplus_get_block+0x40c/0x1600 fs/hfsplus/extents.c:245
       __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
       block_write_begin fs/buffer.c:2256 [inline]
       cont_write_begin+0x78c/0xb50 fs/buffer.c:2594
       hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
       page_symlink+0x26f/0x430 fs/namei.c:6277
       hfsplus_symlink+0xca/0x260 fs/hfsplus/dir.c:449
       vfs_symlink+0x29a/0x2d0 fs/namei.c:5514
       do_symlinkat+0x1f5/0x3d0 fs/namei.c:5541
       __do_sys_symlink fs/namei.c:5567 [inline]
       __se_sys_symlink fs/namei.c:5565 [inline]
       __x64_sys_symlink+0x7a/0x90 fs/namei.c:5565
       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

other info that might help us debug this:

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

5 locks held by syz.1.97/6508:
 #0: ffff888031666480 (sb_writers#25){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
 #1: ffff88802c0b28d8 (&sb->s_type->i_mutex_key#34/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1072 [inline]
 #1: ffff88802c0b28d8 (&sb->s_type->i_mutex_key#34/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2864 [inline]
 #1: ffff88802c0b28d8 (&sb->s_type->i_mutex_key#34/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2875 [inline]
 #1: ffff88802c0b28d8 (&sb->s_type->i_mutex_key#34/1){+.+.}-{4:4}, at: filename_create+0x1fb/0x360 fs/namei.c:4879
 #2: ffff888027cb2978 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_symlink+0x81/0x260 fs/hfsplus/dir.c:444
 #3: ffff88802c0b2df8 (&hip->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x1f8/0x1c40 fs/hfsplus/extents.c:453
 #4: ffff888027cb28e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa7/0xd10 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 0 UID: 0 PID: 6508 Comm: syz.1.97 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
 __mutex_lock_common kernel/locking/rtmutex_api.c:533 [inline]
 mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
 hfsplus_get_block+0x39a/0x1600 fs/hfsplus/extents.c:260
 block_read_full_folio+0x29f/0x830 fs/buffer.c:2420
 filemap_read_folio+0x117/0x380 mm/filemap.c:2496
 do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4096
 do_read_cache_page mm/filemap.c:4162 [inline]
 read_cache_page+0x5d/0x170 mm/filemap.c:4171
 read_mapping_page include/linux/pagemap.h:1011 [inline]
 hfsplus_block_allocate+0xf3/0xd10 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0xa9a/0x1c40 fs/hfsplus/extents.c:464
 hfsplus_get_block+0x40c/0x1600 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin fs/buffer.c:2256 [inline]
 cont_write_begin+0x78c/0xb50 fs/buffer.c:2594
 hfsplus_write_begin+0x66/0xb0 fs/hfsplus/inode.c:48
 page_symlink+0x26f/0x430 fs/namei.c:6277
 hfsplus_symlink+0xca/0x260 fs/hfsplus/dir.c:449
 vfs_symlink+0x29a/0x2d0 fs/namei.c:5514
 do_symlinkat+0x1f5/0x3d0 fs/namei.c:5541
 __do_sys_symlink fs/namei.c:5567 [inline]
 __se_sys_symlink fs/namei.c:5565 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:5565
 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: 0033:0x7fba3880f749
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:00007fba36a76038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007fba38a65fa0 RCX: 00007fba3880f749
RDX: 0000000000000000 RSI: 0000200000000800 RDI: 0000200000000540
RBP: 00007fba38893f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba38a66038 R14: 00007fba38a65fa0 R15: 00007fff09c15898
 </TASK>