======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.7.994/17407 is trying to acquire lock:
ffff88805ea36638 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{4:4}, at: hfsplus_get_block+0x391/0x1610 fs/hfsplus/extents.c:264

but task is already holding lock:
ffff888060fad8e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa9/0xd30 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:561 [inline]
       mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:580
       hfsplus_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35
       hfsplus_file_extend+0xb77/0x1df0 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x41f/0x1610 fs/hfsplus/extents.c:249
       get_more_blocks fs/direct-io.c:644 [inline]
       do_direct_IO fs/direct-io.c:932 [inline]
       __blockdev_direct_IO+0x1965/0x33d0 fs/direct-io.c:1236
       blockdev_direct_IO include/linux/fs.h:3155 [inline]
       hfsplus_direct_IO+0x220/0x370 fs/hfsplus/inode.c:174
       generic_file_direct_write+0x1d1/0x3f0 mm/filemap.c:4308
       __generic_file_write_iter+0x120/0x240 mm/filemap.c:4477
       generic_file_write_iter+0xaf/0x330 mm/filemap.c:4517
       iter_file_splice_write+0xa36/0x1240 fs/splice.c:736
       do_splice_from fs/splice.c:936 [inline]
       direct_splice_actor+0x104/0x160 fs/splice.c:1159
       splice_direct_to_actor+0x586/0xcc0 fs/splice.c:1103
       do_splice_direct_actor fs/splice.c:1202 [inline]
       do_splice_direct+0x19b/0x2a0 fs/splice.c:1228
       do_sendfile+0x540/0x7e0 fs/read_write.c:1371
       __do_sys_sendfile64 fs/read_write.c:1432 [inline]
       __se_sys_sendfile64+0x144/0x1a0 fs/read_write.c:1418
       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 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{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_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
       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_write+0x156/0x270 fs/read_write.c:739
       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(&sbi->alloc_mutex);
                               lock(&HFSPLUS_I(inode)->extents_lock);
                               lock(&sbi->alloc_mutex);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

locks held by syz.7.994/17407: 5, last CPU#1:
 #0: ffff888039b09728 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
 #1: ffff88806336c510 (sb_writers#27){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2753 [inline]
 #1: ffff88806336c510 (sb_writers#27){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
 #2: ffff88805ea36ec8 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #2: ffff88805ea36ec8 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: generic_file_write_iter+0x83/0x330 mm/filemap.c:4514
 #3: ffff88805ea36cf8 (&hip->extents_lock){+.+.}-{4:4}, at: hfsplus_file_extend+0x21c/0x1df0 fs/hfsplus/extents.c:457
 #4: ffff888060fad8e8 (&sbi->alloc_mutex){+.+.}-{4:4}, at: hfsplus_block_allocate+0xa9/0xd30 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 UID: 0 PID: 17407 Comm: syz.7.994 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_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
 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_write+0x156/0x270 fs/read_write.c:739
 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: 0033:0x7f2afb78e159
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:00007f2af99c5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f2afba16090 RCX: 00007f2afb78e159
RDX: 0000000000000031 RSI: 00002000000000c0 RDI: 0000000000000005
RBP: 00007f2afb82506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2afba16128 R14: 00007f2afba16090 R15: 00007ffdd69e1cc8
 </TASK>