u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 0 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 237:893353206280 gen 0
======================================================
WARNING: possible circular locking dependency detected
6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 Not tainted
------------------------------------------------------
syz.2.330/8664 is trying to acquire lock:
ffff000102c481b0 (bcachefs_btree){+.+.}-{0:0}, at: trans_set_locked+0x68/0x200 fs/bcachefs/btree_locking.h:205

but task is already holding lock:
ffff0000f6b182e8 (mapping.invalidate_lock#7){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
ffff0000f6b182e8 (mapping.invalidate_lock#7){.+.+}-{4:4}, at: filemap_fault+0x3fc/0x1280 mm/filemap.c:3433

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #3 (mapping.invalidate_lock#7){.+.+}-{4:4}:
       down_read+0x58/0x2f8 kernel/locking/rwsem.c:1537
       filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
       filemap_fault+0x3fc/0x1280 mm/filemap.c:3433
       bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
       __do_fault+0x1fc/0x4cc mm/memory.c:5152
       do_read_fault mm/memory.c:5573 [inline]
       do_fault mm/memory.c:5707 [inline]
       do_pte_missing mm/memory.c:4234 [inline]
       handle_pte_fault mm/memory.c:6052 [inline]
       __handle_mm_fault mm/memory.c:6195 [inline]
       handle_mm_fault+0x2c90/0x4d34 mm/memory.c:6364
       do_page_fault+0x57c/0x13cc arch/arm64/mm/fault.c:696
       do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:789
       do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:929
       el0_da+0x64/0x164 arch/arm64/kernel/entry-common.c:697
       el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:901
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

-> #2 (&mm->mmap_lock){++++}-{4:4}:
       __might_fault+0xc4/0x124 mm/memory.c:6958
       _inline_copy_to_user include/linux/uaccess.h:192 [inline]
       copy_to_user include/linux/uaccess.h:223 [inline]
       copy_to_user_errcode fs/bcachefs/util.h:701 [inline]
       bch2_ioctl_read_super fs/bcachefs/chardev.c:611 [inline]
       bch2_fs_ioctl+0xb3c/0x13e0 fs/bcachefs/chardev.c:718
       bch2_fs_file_ioctl+0x4dc/0x1964 fs/bcachefs/fs-ioctl.c:411
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:598 [inline]
       __se_sys_ioctl fs/ioctl.c:584 [inline]
       __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:584
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
       el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

-> #1 (&c->sb_lock){+.+.}-{4:4}:
       __mutex_lock_common+0x1d0/0x24ac kernel/locking/mutex.c:598
       __mutex_lock kernel/locking/mutex.c:760 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:812
       __bch2_trans_mark_dev_sb fs/bcachefs/buckets.c:1129 [inline]
       bch2_trans_mark_dev_sb+0xd8/0x67c fs/bcachefs/buckets.c:1176
       bch2_trans_mark_dev_sbs_flags+0x414/0x47c fs/bcachefs/buckets.c:1186
       bch2_mark_superblocks fs/bcachefs/btree_gc.c:805 [inline]
       bch2_check_allocations+0x52c/0x3c34 fs/bcachefs/btree_gc.c:1089
       bch2_run_recovery_pass fs/bcachefs/recovery_passes.c:484 [inline]
       __bch2_run_recovery_passes+0x2b8/0xd54 fs/bcachefs/recovery_passes.c:539
       bch2_run_recovery_passes+0x174/0x1f4 fs/bcachefs/recovery_passes.c:610
       bch2_fs_recovery+0x1c34/0x2fb4 fs/bcachefs/recovery.c:1016
       bch2_fs_start+0x940/0xbec fs/bcachefs/super.c:1213
       bch2_fs_get_tree+0x880/0x107c fs/bcachefs/fs.c:2488
       vfs_get_tree+0x90/0x28c fs/super.c:1815
       do_new_mount+0x278/0x7f4 fs/namespace.c:3805
       path_mount+0x5b4/0xde0 fs/namespace.c:4120
       do_mount fs/namespace.c:4133 [inline]
       __do_sys_mount fs/namespace.c:4344 [inline]
       __se_sys_mount fs/namespace.c:4321 [inline]
       __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4321
       __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
       invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
       el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
       do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
       el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
       el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

-> #0 (bcachefs_btree){+.+.}-{0:0}:
       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+0x1774/0x30a4 kernel/locking/lockdep.c:5237
       lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
       trans_set_locked+0x94/0x200 fs/bcachefs/btree_locking.h:206
       bch2_trans_begin+0x800/0xd30 fs/bcachefs/btree_iter.c:3403
       bch2_read_err_msg_trans+0x64/0x298 fs/bcachefs/io_read.c:374
       __bch2_read_extent+0x25f0/0x3638 fs/bcachefs/io_read.c:1070
       bch2_read_extent fs/bcachefs/io_read.h:147 [inline]
       bchfs_read+0x107c/0x17e8 fs/bcachefs/fs-io-buffered.c:226
       bch2_read_single_folio+0x498/0x6e4 fs/bcachefs/fs-io-buffered.c:360
       bch2_read_folio+0x40/0x84 fs/bcachefs/fs-io-buffered.c:378
       filemap_read_folio+0xec/0x2f8 mm/filemap.c:2413
       filemap_fault+0xd48/0x1280 mm/filemap.c:3537
       bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
       __do_fault+0x1fc/0x4cc mm/memory.c:5152
       do_read_fault mm/memory.c:5573 [inline]
       do_fault mm/memory.c:5707 [inline]
       do_pte_missing mm/memory.c:4234 [inline]
       handle_pte_fault mm/memory.c:6052 [inline]
       __handle_mm_fault mm/memory.c:6195 [inline]
       handle_mm_fault+0x2c90/0x4d34 mm/memory.c:6364
       do_page_fault+0x8a0/0x13cc arch/arm64/mm/fault.c:696
       do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:789
       do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:929
       el0_da+0x64/0x164 arch/arm64/kernel/entry-common.c:697
       el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:901
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

other info that might help us debug this:

Chain exists of:
  bcachefs_btree --> &mm->mmap_lock --> mapping.invalidate_lock#7

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(mapping.invalidate_lock#7);
                               lock(&mm->mmap_lock);
                               lock(mapping.invalidate_lock#7);
  lock(bcachefs_btree);

 *** DEADLOCK ***

2 locks held by syz.2.330/8664:
 #0: ffff0000c2c65e50 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:472 [inline]
 #0: ffff0000c2c65e50 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/mmap_lock.c:277 [inline]
 #0: ffff0000c2c65e50 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x38/0x2d8 mm/mmap_lock.c:337
 #1: ffff0000f6b182e8 (mapping.invalidate_lock#7){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:934 [inline]
 #1: ffff0000f6b182e8 (mapping.invalidate_lock#7){.+.+}-{4:4}, at: filemap_fault+0x3fc/0x1280 mm/filemap.c:3433

stack backtrace:
CPU: 0 UID: 0 PID: 8664 Comm: syz.2.330 Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 print_circular_bug+0x324/0x32c kernel/locking/lockdep.c:2043
 check_noncircular+0x154/0x174 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+0x1774/0x30a4 kernel/locking/lockdep.c:5237
 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5868
 trans_set_locked+0x94/0x200 fs/bcachefs/btree_locking.h:206
 bch2_trans_begin+0x800/0xd30 fs/bcachefs/btree_iter.c:3403
 bch2_read_err_msg_trans+0x64/0x298 fs/bcachefs/io_read.c:374
 __bch2_read_extent+0x25f0/0x3638 fs/bcachefs/io_read.c:1070
 bch2_read_extent fs/bcachefs/io_read.h:147 [inline]
 bchfs_read+0x107c/0x17e8 fs/bcachefs/fs-io-buffered.c:226
 bch2_read_single_folio+0x498/0x6e4 fs/bcachefs/fs-io-buffered.c:360
 bch2_read_folio+0x40/0x84 fs/bcachefs/fs-io-buffered.c:378
 filemap_read_folio+0xec/0x2f8 mm/filemap.c:2413
 filemap_fault+0xd48/0x1280 mm/filemap.c:3537
 bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
 __do_fault+0x1fc/0x4cc mm/memory.c:5152
 do_read_fault mm/memory.c:5573 [inline]
 do_fault mm/memory.c:5707 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x2c90/0x4d34 mm/memory.c:6364
 do_page_fault+0x8a0/0x13cc arch/arm64/mm/fault.c:696
 do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:789
 do_mem_abort+0x70/0x194 arch/arm64/mm/fault.c:929
 el0_da+0x64/0x164 arch/arm64/kernel/entry-common.c:697
 el0t_64_sync_handler+0x90/0x12c arch/arm64/kernel/entry-common.c:901
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
bcachefs (loop2): /file3 offset 0: no_devices_valid
  u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 0 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 237:893353206280 gen 0
bcachefs (loop2): /file3 offset 0: no_devices_valid
  u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 0 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 237:893353206280 gen 0
bcachefs (loop2): /file3 offset 0: no_devices_valid
  u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 0 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 237:893353206280 gen 0
bcachefs (loop2): /file3 offset 0: no_devices_valid
  u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 0 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 237:893353206280 gen 0
bcachefs (loop2): /file3 offset 0: no_devices_valid
  u64s 7 type extent 536870913:24:U32_MAX len 24 ver 0: durability: 0 crc: c_size 8 size 24 offset 0 nonce 0 csum none 0:0  compress lz4 ptr: 237:893353206280 gen 0