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Subject[syzbot] possible deadlock in hfsplus_get_block
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Hello,

syzbot found the following issue on:

HEAD commit: 4312098baf37 Merge tag 'spi-fix-v6.1-rc6' of git://git.ker..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=121367e5880000
kernel config: https://syzkaller.appspot.com/x/.config?x=8d01b6e3197974dd
dashboard link: https://syzkaller.appspot.com/bug?extid=b7ef7c0c8d8098686ae2
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=122d9403880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1150559b880000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4b7073d20a37/disk-4312098b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/36a0367a5593/vmlinux-4312098b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/265bedb3086b/bzImage-4312098b.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/1a892c1e3bf7/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+b7ef7c0c8d8098686ae2@syzkaller.appspotmail.com

============================================
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


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
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syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

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