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
6.16.0-rc1-syzkaller-g39dfc971e42d #0 Not tainted
------------------------------------------------------
syz.2.57/6807 is trying to acquire lock:
ffff0000f68b41b0 (bcachefs_btree){+.+.}-{0:0}, at: trans_set_locked+0x68/0x200 fs/bcachefs/btree_locking.h:205

but task is already holding lock:
ffff0000f4210a80 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
ffff0000f4210a80 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x3fc/0x1280 mm/filemap.c:3400

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (mapping.invalidate_lock#3){.+.+}-{4:4}:
       down_read+0x58/0x2f8 kernel/locking/rwsem.c:1524
       filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
       filemap_fault+0x3fc/0x1280 mm/filemap.c:3400
       bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
       __do_fault+0x1fc/0x4cc mm/memory.c:5189
       do_read_fault mm/memory.c:5610 [inline]
       do_fault mm/memory.c:5744 [inline]
       do_pte_missing mm/memory.c:4251 [inline]
       handle_pte_fault mm/memory.c:6089 [inline]
       __handle_mm_fault mm/memory.c:6232 [inline]
       handle_mm_fault+0x2c94/0x4d38 mm/memory.c:6401
       faultin_page mm/gup.c:1186 [inline]
       __get_user_pages+0x1ddc/0x309c mm/gup.c:1488
       populate_vma_page_range+0x218/0x2e8 mm/gup.c:1926
       __mm_populate+0x208/0x330 mm/gup.c:2029
       mm_populate include/linux/mm.h:3348 [inline]
       vm_mmap_pgoff+0x378/0x43c mm/util.c:584
       ksys_mmap_pgoff+0x394/0x5b8 mm/mmap.c:607
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
       __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+0x58/0x17c arch/arm64/kernel/entry-common.c:767
       el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #6 (&mm->mmap_lock){++++}-{4:4}:
       __might_fault+0xc4/0x124 mm/memory.c:6991
       drm_mode_setcrtc+0xdc0/0x182c drivers/gpu/drm/drm_crtc.c:840
       drm_ioctl_kernel+0x238/0x310 drivers/gpu/drm/drm_ioctl.c:796
       drm_ioctl+0x65c/0xa5c drivers/gpu/drm/drm_ioctl.c:893
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:907 [inline]
       __se_sys_ioctl fs/ioctl.c:893 [inline]
       __arm64_sys_ioctl+0x14c/0x1c4 fs/ioctl.c:893
       __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+0x58/0x17c arch/arm64/kernel/entry-common.c:767
       el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #5 (crtc_ww_class_mutex){+.+.}-{4:4}:
       ww_acquire_init include/linux/ww_mutex.h:162 [inline]
       drm_modeset_acquire_init+0x1d8/0x374 drivers/gpu/drm/drm_modeset_lock.c:250
       drmm_mode_config_init+0xb44/0x1118 drivers/gpu/drm/drm_mode_config.c:469
       vkms_modeset_init drivers/gpu/drm/vkms/vkms_drv.c:127 [inline]
       vkms_create drivers/gpu/drm/vkms/vkms_drv.c:191 [inline]
       vkms_init+0x2a8/0x548 drivers/gpu/drm/vkms/vkms_drv.c:221
       do_one_initcall+0x250/0x990 init/main.c:1273
       do_initcall_level+0x154/0x214 init/main.c:1335
       do_initcalls+0x84/0xf4 init/main.c:1351
       do_basic_setup+0x8c/0xa0 init/main.c:1370
       kernel_init_freeable+0x2dc/0x444 init/main.c:1583
       kernel_init+0x24/0x1dc init/main.c:1473
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

-> #4 (crtc_ww_class_acquire){+.+.}-{0:0}:
       ww_acquire_init include/linux/ww_mutex.h:161 [inline]
       drm_modeset_acquire_init+0x1b8/0x374 drivers/gpu/drm/drm_modeset_lock.c:250
       drm_client_modeset_commit_atomic+0xcc/0x6ac drivers/gpu/drm/drm_client_modeset.c:1040
       drm_client_modeset_commit_locked+0xd0/0x4a0 drivers/gpu/drm/drm_client_modeset.c:1204
       drm_client_modeset_commit+0x50/0x7c drivers/gpu/drm/drm_client_modeset.c:1230
       __drm_fb_helper_restore_fbdev_mode_unlocked+0x94/0x198 drivers/gpu/drm/drm_fb_helper.c:237
       drm_fb_helper_set_par+0xa4/0x108 drivers/gpu/drm/drm_fb_helper.c:1359
       fbcon_init+0xe58/0x1d0c drivers/video/fbdev/core/fbcon.c:1117
       visual_init+0x27c/0x540 drivers/tty/vt/vt.c:1019
       do_bind_con_driver+0x7b8/0xdd8 drivers/tty/vt/vt.c:3915
       do_take_over_console+0x824/0x97c drivers/tty/vt/vt.c:4481
       do_fbcon_takeover+0x158/0x25c drivers/video/fbdev/core/fbcon.c:553
       do_fb_registered drivers/video/fbdev/core/fbcon.c:2994 [inline]
       fbcon_fb_registered+0x354/0x4c8 drivers/video/fbdev/core/fbcon.c:3014
       do_register_framebuffer drivers/video/fbdev/core/fbmem.c:509 [inline]
       register_framebuffer+0x538/0x6c8 drivers/video/fbdev/core/fbmem.c:575
       __drm_fb_helper_initial_config_and_unlock+0x103c/0x159c drivers/gpu/drm/drm_fb_helper.c:1851
       drm_fb_helper_initial_config+0x3c/0x58 drivers/gpu/drm/drm_fb_helper.c:1916
       drm_fbdev_client_hotplug+0x154/0x22c drivers/gpu/drm/clients/drm_fbdev_client.c:52
       drm_client_register+0x13c/0x1d4 drivers/gpu/drm/drm_client.c:140
       drm_fbdev_client_setup+0x194/0x3d0 drivers/gpu/drm/clients/drm_fbdev_client.c:159
       drm_client_setup+0x78/0x140 drivers/gpu/drm/clients/drm_client_setup.c:39
       vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline]
       vkms_init+0x498/0x548 drivers/gpu/drm/vkms/vkms_drv.c:221
       do_one_initcall+0x250/0x990 init/main.c:1273
       do_initcall_level+0x154/0x214 init/main.c:1335
       do_initcalls+0x84/0xf4 init/main.c:1351
       do_basic_setup+0x8c/0xa0 init/main.c:1370
       kernel_init_freeable+0x2dc/0x444 init/main.c:1583
       kernel_init+0x24/0x1dc init/main.c:1473
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

-> #3 (&client->modeset_mutex){+.+.}-{4:4}:
       __mutex_lock_common+0x1d0/0x2190 kernel/locking/mutex.c:602
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
       drm_client_modeset_probe+0x2e8/0x4d7c drivers/gpu/drm/drm_client_modeset.c:863
       __drm_fb_helper_initial_config_and_unlock+0xf0/0x159c drivers/gpu/drm/drm_fb_helper.c:1828
       drm_fb_helper_initial_config+0x3c/0x58 drivers/gpu/drm/drm_fb_helper.c:1916
       drm_fbdev_client_hotplug+0x154/0x22c drivers/gpu/drm/clients/drm_fbdev_client.c:52
       drm_client_register+0x13c/0x1d4 drivers/gpu/drm/drm_client.c:140
       drm_fbdev_client_setup+0x194/0x3d0 drivers/gpu/drm/clients/drm_fbdev_client.c:159
       drm_client_setup+0x78/0x140 drivers/gpu/drm/clients/drm_client_setup.c:39
       vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline]
       vkms_init+0x498/0x548 drivers/gpu/drm/vkms/vkms_drv.c:221
       do_one_initcall+0x250/0x990 init/main.c:1273
       do_initcall_level+0x154/0x214 init/main.c:1335
       do_initcalls+0x84/0xf4 init/main.c:1351
       do_basic_setup+0x8c/0xa0 init/main.c:1370
       kernel_init_freeable+0x2dc/0x444 init/main.c:1583
       kernel_init+0x24/0x1dc init/main.c:1473
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

-> #2 (&helper->lock){+.+.}-{4:4}:
       __mutex_lock_common+0x1d0/0x2190 kernel/locking/mutex.c:602
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:799
       __drm_fb_helper_restore_fbdev_mode_unlocked+0x74/0x198 drivers/gpu/drm/drm_fb_helper.c:228
       drm_fb_helper_set_par+0xa4/0x108 drivers/gpu/drm/drm_fb_helper.c:1359
       fbcon_init+0xe58/0x1d0c drivers/video/fbdev/core/fbcon.c:1117
       visual_init+0x27c/0x540 drivers/tty/vt/vt.c:1019
       do_bind_con_driver+0x7b8/0xdd8 drivers/tty/vt/vt.c:3915
       do_take_over_console+0x824/0x97c drivers/tty/vt/vt.c:4481
       do_fbcon_takeover+0x158/0x25c drivers/video/fbdev/core/fbcon.c:553
       do_fb_registered drivers/video/fbdev/core/fbcon.c:2994 [inline]
       fbcon_fb_registered+0x354/0x4c8 drivers/video/fbdev/core/fbcon.c:3014
       do_register_framebuffer drivers/video/fbdev/core/fbmem.c:509 [inline]
       register_framebuffer+0x538/0x6c8 drivers/video/fbdev/core/fbmem.c:575
       __drm_fb_helper_initial_config_and_unlock+0x103c/0x159c drivers/gpu/drm/drm_fb_helper.c:1851
       drm_fb_helper_initial_config+0x3c/0x58 drivers/gpu/drm/drm_fb_helper.c:1916
       drm_fbdev_client_hotplug+0x154/0x22c drivers/gpu/drm/clients/drm_fbdev_client.c:52
       drm_client_register+0x13c/0x1d4 drivers/gpu/drm/drm_client.c:140
       drm_fbdev_client_setup+0x194/0x3d0 drivers/gpu/drm/clients/drm_fbdev_client.c:159
       drm_client_setup+0x78/0x140 drivers/gpu/drm/clients/drm_client_setup.c:39
       vkms_create drivers/gpu/drm/vkms/vkms_drv.c:201 [inline]
       vkms_init+0x498/0x548 drivers/gpu/drm/vkms/vkms_drv.c:221
       do_one_initcall+0x250/0x990 init/main.c:1273
       do_initcall_level+0x154/0x214 init/main.c:1335
       do_initcalls+0x84/0xf4 init/main.c:1351
       do_basic_setup+0x8c/0xa0 init/main.c:1370
       kernel_init_freeable+0x2dc/0x444 init/main.c:1583
       kernel_init+0x24/0x1dc init/main.c:1473
       ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

-> #1 (console_lock){+.+.}-{0:0}:
       console_lock+0x194/0x1ec kernel/printk/printk.c:2849
       bch2_print_string_as_lines+0x68/0x260 fs/bcachefs/util.c:277
       __bch2_print_str fs/bcachefs/super.c:117 [inline]
       bch2_print_str+0x94/0xd0 fs/bcachefs/super.c:122
       bch2_dev_missing_bkey+0x124/0x188 fs/bcachefs/sb-members.c:27
       bch2_bkey_pick_read_device+0x954/0x133c fs/bcachefs/extents.c:224
       __bch2_read_extent+0x6f0/0x3638 fs/bcachefs/io_read.c:1040
       bch2_read_extent fs/bcachefs/io_read.h:146 [inline]
       bchfs_read+0x107c/0x17e8 fs/bcachefs/fs-io-buffered.c:226
       bch2_readahead+0xa18/0xd88 fs/bcachefs/fs-io-buffered.c:316
       read_pages+0x13c/0x4c4 mm/readahead.c:160
       page_cache_ra_order+0x7b8/0xb34 mm/readahead.c:515
       do_sync_mmap_readahead+0x2f0/0x660 mm/filemap.c:-1
       filemap_fault+0x5e4/0x1280 mm/filemap.c:3412
       bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
       __do_fault+0x1fc/0x4cc mm/memory.c:5189
       do_read_fault mm/memory.c:5610 [inline]
       do_fault mm/memory.c:5744 [inline]
       do_pte_missing mm/memory.c:4251 [inline]
       handle_pte_fault mm/memory.c:6089 [inline]
       __handle_mm_fault mm/memory.c:6232 [inline]
       handle_mm_fault+0x2c94/0x4d38 mm/memory.c:6401
       faultin_page mm/gup.c:1186 [inline]
       __get_user_pages+0x1ddc/0x309c mm/gup.c:1488
       populate_vma_page_range+0x218/0x2e8 mm/gup.c:1926
       __mm_populate+0x208/0x330 mm/gup.c:2029
       mm_populate include/linux/mm.h:3348 [inline]
       vm_mmap_pgoff+0x378/0x43c mm/util.c:584
       ksys_mmap_pgoff+0x394/0x5b8 mm/mmap.c:607
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
       __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+0x58/0x17c arch/arm64/kernel/entry-common.c:767
       el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #0 (bcachefs_btree){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain kernel/locking/lockdep.c:3911 [inline]
       __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5240
       lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5871
       trans_set_locked+0x94/0x200 fs/bcachefs/btree_locking.h:206
       bch2_trans_begin+0x71c/0xaac fs/bcachefs/btree_iter.c:3338
       bch2_read_err_msg_trans+0x64/0x298 fs/bcachefs/io_read.c:369
       __bch2_read_extent+0x25f0/0x3638 fs/bcachefs/io_read.c:1058
       bch2_read_extent fs/bcachefs/io_read.h:146 [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:2412
       filemap_fault+0xd48/0x1280 mm/filemap.c:3504
       bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
       __do_fault+0x1fc/0x4cc mm/memory.c:5189
       do_read_fault mm/memory.c:5610 [inline]
       do_fault mm/memory.c:5744 [inline]
       do_pte_missing mm/memory.c:4251 [inline]
       handle_pte_fault mm/memory.c:6089 [inline]
       __handle_mm_fault mm/memory.c:6232 [inline]
       handle_mm_fault+0x2c94/0x4d38 mm/memory.c:6401
       faultin_page mm/gup.c:1186 [inline]
       __get_user_pages+0x1ddc/0x309c mm/gup.c:1488
       populate_vma_page_range+0x218/0x2e8 mm/gup.c:1926
       __mm_populate+0x208/0x330 mm/gup.c:2029
       mm_populate include/linux/mm.h:3348 [inline]
       vm_mmap_pgoff+0x378/0x43c mm/util.c:584
       ksys_mmap_pgoff+0x394/0x5b8 mm/mmap.c:607
       __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
       __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
       __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
       __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+0x58/0x17c arch/arm64/kernel/entry-common.c:767
       el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
       el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

other info that might help us debug this:

Chain exists of:
  bcachefs_btree --> &mm->mmap_lock --> mapping.invalidate_lock#3

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(mapping.invalidate_lock#3);
                               lock(&mm->mmap_lock);
                               lock(mapping.invalidate_lock#3);
  lock(bcachefs_btree);

 *** DEADLOCK ***

1 lock held by syz.2.57/6807:
 #0: ffff0000f4210a80 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
 #0: ffff0000f4210a80 (mapping.invalidate_lock#3){.+.+}-{4:4}, at: filemap_fault+0x3fc/0x1280 mm/filemap.c:3400

stack backtrace:
CPU: 0 UID: 0 PID: 6807 Comm: syz.2.57 Not tainted 6.16.0-rc1-syzkaller-g39dfc971e42d #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (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:2046
 check_noncircular+0x154/0x174 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x1774/0x30a4 kernel/locking/lockdep.c:5240
 lock_acquire+0x14c/0x2e0 kernel/locking/lockdep.c:5871
 trans_set_locked+0x94/0x200 fs/bcachefs/btree_locking.h:206
 bch2_trans_begin+0x71c/0xaac fs/bcachefs/btree_iter.c:3338
 bch2_read_err_msg_trans+0x64/0x298 fs/bcachefs/io_read.c:369
 __bch2_read_extent+0x25f0/0x3638 fs/bcachefs/io_read.c:1058
 bch2_read_extent fs/bcachefs/io_read.h:146 [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:2412
 filemap_fault+0xd48/0x1280 mm/filemap.c:3504
 bch2_page_fault+0x2cc/0x700 fs/bcachefs/fs-io-pagecache.c:594
 __do_fault+0x1fc/0x4cc mm/memory.c:5189
 do_read_fault mm/memory.c:5610 [inline]
 do_fault mm/memory.c:5744 [inline]
 do_pte_missing mm/memory.c:4251 [inline]
 handle_pte_fault mm/memory.c:6089 [inline]
 __handle_mm_fault mm/memory.c:6232 [inline]
 handle_mm_fault+0x2c94/0x4d38 mm/memory.c:6401
 faultin_page mm/gup.c:1186 [inline]
 __get_user_pages+0x1ddc/0x309c mm/gup.c:1488
 populate_vma_page_range+0x218/0x2e8 mm/gup.c:1926
 __mm_populate+0x208/0x330 mm/gup.c:2029
 mm_populate include/linux/mm.h:3348 [inline]
 vm_mmap_pgoff+0x378/0x43c mm/util.c:584
 ksys_mmap_pgoff+0x394/0x5b8 mm/mmap.c:607
 __do_sys_mmap arch/arm64/kernel/sys.c:28 [inline]
 __se_sys_mmap arch/arm64/kernel/sys.c:21 [inline]
 __arm64_sys_mmap+0xf8/0x110 arch/arm64/kernel/sys.c:21
 __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+0x58/0x17c arch/arm64/kernel/entry-common.c:767
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600