syzbot

============================================
WARNING: possible recursive locking detected
6.1.0-rc6-syzkaller-00012-g4312098baf37 #0 Not tainted
--------------------------------------------
syz-executor378/3638 is trying to acquire lock:
ffff888023aa1548 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_get_block+0x3a3/0x1560 fs/hfsplus/extents.c:260

but task is already holding lock:
ffff888023aa3048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1af/0x19d0 fs/hfsplus/extents.c:457

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&HFSPLUS_I(inode)->extents_lock);
  lock(&HFSPLUS_I(inode)->extents_lock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz-executor378/3638:
 #0: ffff888026644460 (sb_writers#9){.+.+}-{0:0}, at: do_sys_ftruncate+0x24f/0x380 fs/open.c:190
 #1: ffff888023aa3240 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #1: ffff888023aa3240 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: do_truncate+0x1e7/0x2e0 fs/open.c:63
 #2: ffff888023aa3048 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x1af/0x19d0 fs/hfsplus/extents.c:457
 #3: ffff88807743d8f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x9f/0x900 fs/hfsplus/bitmap.c:35

stack backtrace:
CPU: 1 PID: 3638 Comm: syz-executor378 Not tainted 6.1.0-rc6-syzkaller-00012-g4312098baf37 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106
 print_deadlock_bug kernel/locking/lockdep.c:2990 [inline]
 check_deadlock kernel/locking/lockdep.c:3033 [inline]
 validate_chain+0x4843/0x6ae0 kernel/locking/lockdep.c:3818
 __lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
 lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
 __mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
 hfsplus_get_block+0x3a3/0x1560 fs/hfsplus/extents.c:260
 block_read_full_folio+0x3b3/0xfa0 fs/buffer.c:2271
 filemap_read_folio+0x187/0x7d0 mm/filemap.c:2407
 do_read_cache_folio+0x2d3/0x790 mm/filemap.c:3534
 do_read_cache_page mm/filemap.c:3576 [inline]
 read_cache_page+0x56/0x270 mm/filemap.c:3585
 read_mapping_page include/linux/pagemap.h:756 [inline]
 hfsplus_block_allocate+0xf9/0x900 fs/hfsplus/bitmap.c:37
 hfsplus_file_extend+0x9d4/0x19d0 fs/hfsplus/extents.c:468
 hfsplus_get_block+0x415/0x1560 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
 __block_write_begin fs/buffer.c:2041 [inline]
 block_write_begin+0x93/0x1e0 fs/buffer.c:2102
 cont_write_begin+0x606/0x860 fs/buffer.c:2456
 hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
 cont_expand_zero fs/buffer.c:2383 [inline]
 cont_write_begin+0x2cf/0x860 fs/buffer.c:2446
 hfsplus_write_begin+0x86/0xd0 fs/hfsplus/inode.c:52
 generic_cont_expand_simple+0x151/0x250 fs/buffer.c:2347
 hfsplus_setattr+0x168/0x280 fs/hfsplus/inode.c:263
 notify_change+0xe38/0x10f0 fs/attr.c:420
 do_truncate+0x1fb/0x2e0 fs/open.c:65
 do_sys_ftruncate+0x2eb/0x380 fs/open.c:193
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f838df947c9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 14 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffb8a18448 EFLAGS: 00000246 ORIG