syzbot

loop0: detected capacity change from 0 to 1024
======================================================
WARNING: possible circular locking dependency detected
6.8.0-syzkaller-05562-g61387b8dcf1d #0 Not tainted
------------------------------------------------------
syz-executor170/6261 is trying to acquire lock:
ffff88807f2b10f8 (&sbi->alloc_mutex){+.+.}-{3:3}, at: hfsplus_block_allocate+0x9e/0x8c0 fs/hfsplus/bitmap.c:35

but task is already holding lock:
ffff88807f19df88 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x21b/0x1b70 fs/hfsplus/extents.c:457

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}:
       lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       hfsplus_get_block+0x383/0x14f0 fs/hfsplus/extents.c:260
       block_read_full_folio+0x42e/0xe10 fs/buffer.c:2384
       filemap_read_folio+0x1a0/0x790 mm/filemap.c:2324
       do_read_cache_folio+0x134/0x820 mm/filemap.c:3694
       do_read_cache_page+0x30/0x200 mm/filemap.c:3760
       read_mapping_page include/linux/pagemap.h:888 [inline]
       hfsplus_block_allocate+0xee/0x8c0 fs/hfsplus/bitmap.c:37
       hfsplus_file_extend+0xade/0x1b70 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x406/0x14f0 fs/hfsplus/extents.c:245
       __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2105
       __block_write_begin fs/buffer.c:2154 [inline]
       block_write_begin+0x9b/0x1e0 fs/buffer.c:2213
       cont_write_begin+0x645/0x890 fs/buffer.c:2567
       hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
       cont_expand_zero fs/buffer.c:2527 [inline]
       cont_write_begin+0x6ee/0x890 fs/buffer.c:2557
       hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
       generic_cont_expand_simple+0x18f/0x2b0 fs/buffer.c:2458
       hfsplus_setattr+0x178/0x280 fs/hfsplus/inode.c:259
       notify_change+0xb9d/0xe70 fs/attr.c:497
       do_truncate fs/open.c:65 [inline]
       do_ftruncate+0x46b/0x590 fs/open.c:181
       do_sys_ftruncate fs/open.c:199 [inline]
       __do_sys_ftruncate fs/open.c:207 [inline]
       __se_sys_ftruncate fs/open.c:205 [inline]
       __x64_sys_ftruncate+0x95/0xf0 fs/open.c:205
       do_syscall_64+0xfb/0x240
       entry_SYSCALL_64_after_hwframe+0x6d/0x75

-> #0 (&sbi->alloc_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       hfsplus_block_allocate+0x9e/0x8c0 fs/hfsplus/bitmap.c:35
       hfsplus_file_extend+0xade/0x1b70 fs/hfsplus/extents.c:468
       hfsplus_get_block+0x406/0x14f0 fs/hfsplus/extents.c:245
       __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2105
       __block_write_begin fs/buffer.c:2154 [inline]
       block_write_begin+0x9b/0x1e0 fs/buffer.c:2213
       cont_write_begin+0x645/0x890 fs/buffer.c:2567
       hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
       cont_expand_zero fs/buffer.c:2494 [inline]
       cont_write_begin+0x319/0x890 fs/buffer.c:2557
       hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
       generic_perform_write+0x322/0x640 mm/filemap.c:3921
       generic_file_write_iter+0xaf/0x310 mm/filemap.c:4042
       do_iter_readv_writev+0x5a4/0x800
       vfs_writev+0x395/0xbb0 fs/read_write.c:971
       do_pwritev fs/read_write.c:1072 [inline]
       __do_sys_pwritev2 fs/read_write.c:1131 [inline]
       __se_sys_pwritev2+0x1ca/0x2d0 fs/read_write.c:1122
       do_syscall_64+0xfb/0x240
       entry_SYSCALL_64_after_hwframe+0x6d/0x75

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 ***

3 locks held by syz-executor170/6261:
 #0: ffff88806d1ea420 (sb_writers#11){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2853 [inline]
 #0: ffff88806d1ea420 (sb_writers#11){.+.+}-{0:0}, at: vfs_writev+0x2d9/0xbb0 fs/read_write.c:969
 #1: ffff88807f19e180 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:793 [inline]
 #1: ffff88807f19e180 (&sb->s_type->i_mutex_key#17){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x310 mm/filemap.c:4039
 #2: ffff88807f19df88 (&HFSPLUS_I(inode)->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x21b/0x1b70 fs/hfsplus/extents.c:457

stack backtrace:
CPU: 1 PID: 6261 Comm: syz-executor170 Not tainted 6.8.0-syzkaller-05562-g61387b8dcf1d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18cb/0x58e0 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1e4/0x530 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 hfsplus_block_allocate+0x9e/0x8c0 fs/hfsplus/bitmap.c:35
 hfsplus_file_extend+0xade/0x1b70 fs/hfsplus/extents.c:468
 hfsplus_get_block+0x406/0x14f0 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2105
 __block_write_begin fs/buffer.c:2154 [inline]
 block_write_begin+0x9b/0x1e0 fs/buffer.c:2213
 cont_write_begin+0x645/0x890 fs/buffer.c:2567
 hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
 cont_expand_zero fs/buffer.c:2494 [inline]
 cont_write_begin+0x319/0x890 fs/buffer.c:2557
 hfsplus_write_begin+0x8a/0xd0 fs/hfsplus/inode.c:47
 generic_perform_write+0x322/0x640 mm/filemap.c:3921
 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4042
 do_iter_readv_writev+0x5a4/0x800
 vfs_writev+0x395/0xbb0 fs/read_write.c:971
 do_pwritev fs/read_write.c:1072 [inline]
 __do_sys_pwritev2 fs/read_write.c:1131 [inline]
 __se_sys_pwritev2+0x1ca/0x2d0 fs/read_write.c:1122
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7fe7ed3c9299
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 1f 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd9249b938 EFLAGS: 00000216 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fe7ed3c9299
RDX: 0000000000000001 RSI: 00000000200001c0 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000007fff R11: 0000000000000216 R12: 00007ffd9249b978
R13: 0000000000000473 R14: 00007ffd9249b9b0 R15: 431bde82d7b634db
 </TASK>