[syzbot] [btrfs?] possible deadlock in join_transaction (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: feffde684ac2 Merge tag 'for-6.13-rc1-tag' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11b428df980000
kernel config: https://syzkaller.appspot.com/x/.config?x=ad7dafcfaa48849c
dashboard link: https://syzkaller.appspot.com/bug?extid=77cf6638a2a1806ef852
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c51d22ca6229/disk-feffde68.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/282335ac1978/vmlinux-feffde68.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d341f69bc687/bzImage-feffde68.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+77cf66...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0 Not tainted
------------------------------------------------------
kworker/u8:11/15834 is trying to acquire lock:
ffff888067216470 (btrfs_trans_num_writers){++++}-{0:0}, at: join_transaction+0x430/0x1010 fs/btrfs/transaction.c:288

but task is already holding lock:
ffff88801271a610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x3c9/0x2200 fs/btrfs/inode.c:3082

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (sb_internal#4){.+.+}-{0:0}:
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1725 [inline]
sb_start_intwrite include/linux/fs.h:1908 [inline]
start_transaction+0xbd3/0x1aa0 fs/btrfs/transaction.c:691
btrfs_dirty_inode+0xc8/0x200 fs/btrfs/inode.c:6055
btrfs_update_time fs/btrfs/inode.c:6089 [inline]
btrfs_update_time+0xb2/0xf0 fs/btrfs/inode.c:6080
inode_update_time fs/inode.c:2124 [inline]
touch_atime+0x352/0x5d0 fs/inode.c:2197
file_accessed include/linux/fs.h:2539 [inline]
btrfs_file_mmap+0x118/0x150 fs/btrfs/file.c:1953
call_mmap include/linux/fs.h:2183 [inline]
mmap_file mm/internal.h:124 [inline]
__mmap_new_file_vma mm/vma.c:2291 [inline]
__mmap_new_vma mm/vma.c:2355 [inline]
__mmap_region+0x1789/0x2670 mm/vma.c:2456
mmap_region+0x270/0x320 mm/mmap.c:1347
do_mmap+0xc00/0xfc0 mm/mmap.c:496
vm_mmap_pgoff+0x1ba/0x360 mm/util.c:580
ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #7 (&mm->mmap_lock){++++}-{4:4}:
__might_fault mm/memory.c:6751 [inline]
__might_fault+0x11b/0x190 mm/memory.c:6744
_inline_copy_from_user include/linux/uaccess.h:162 [inline]
_copy_from_user+0x29/0xd0 lib/usercopy.c:18
copy_from_user include/linux/uaccess.h:212 [inline]
__blk_trace_setup+0xa8/0x180 kernel/trace/blktrace.c:626
blk_trace_ioctl+0x163/0x290 kernel/trace/blktrace.c:740
blkdev_ioctl+0x109/0x6d0 block/ioctl.c:682
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (&q->debugfs_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
blk_mq_init_sched+0x42b/0x640 block/blk-mq-sched.c:473
elevator_init_mq+0x2cd/0x420 block/elevator.c:610
add_disk_fwnode+0x113/0x1300 block/genhd.c:413
sd_probe+0xa86/0x1000 drivers/scsi/sd.c:4024
call_driver_probe drivers/base/dd.c:579 [inline]
really_probe+0x241/0xa90 drivers/base/dd.c:658
__driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
__device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
bus_for_each_drv+0x15a/0x1e0 drivers/base/bus.c:459
__device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987
async_run_entry_fn+0x9f/0x530 kernel/async.c:129
process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c4/0x3a0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #5 (&q->q_usage_counter(queue)#50){++++}-{0:0}:
blk_queue_enter+0x50f/0x640 block/blk-core.c:328
blk_mq_alloc_request+0x59b/0x950 block/blk-mq.c:651
scsi_alloc_request drivers/scsi/scsi_lib.c:1222 [inline]
scsi_execute_cmd+0x1eb/0xf40 drivers/scsi/scsi_lib.c:304
read_capacity_16+0x213/0xe10 drivers/scsi/sd.c:2655
sd_read_capacity drivers/scsi/sd.c:2824 [inline]
sd_revalidate_disk.isra.0+0x1a06/0xa8d0 drivers/scsi/sd.c:3734
sd_probe+0x904/0x1000 drivers/scsi/sd.c:4010
call_driver_probe drivers/base/dd.c:579 [inline]
really_probe+0x241/0xa90 drivers/base/dd.c:658
__driver_probe_device+0x1de/0x440 drivers/base/dd.c:800
driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:830
__device_attach_driver+0x1df/0x310 drivers/base/dd.c:958
bus_for_each_drv+0x15a/0x1e0 drivers/base/bus.c:459
__device_attach_async_helper+0x1d3/0x290 drivers/base/dd.c:987
async_run_entry_fn+0x9f/0x530 kernel/async.c:129
process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c4/0x3a0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #4 (&q->limits_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
queue_limits_start_update include/linux/blkdev.h:949 [inline]
loop_reconfigure_limits+0x407/0x8c0 drivers/block/loop.c:998
loop_set_block_size drivers/block/loop.c:1473 [inline]
lo_simple_ioctl drivers/block/loop.c:1496 [inline]
lo_ioctl+0x901/0x18b0 drivers/block/loop.c:1559
blkdev_ioctl+0x279/0x6d0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #3 (&q->q_usage_counter(io)#23){++++}-{0:0}:
bio_queue_enter block/blk.h:75 [inline]
blk_mq_submit_bio+0x1fb6/0x24c0 block/blk-mq.c:3091
__submit_bio+0x384/0x540 block/blk-core.c:629
__submit_bio_noacct_mq block/blk-core.c:710 [inline]
submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:739
submit_bio_noacct+0x93a/0x1e20 block/blk-core.c:868
btrfs_submit_dev_bio+0x54d/0xb20 fs/btrfs/bio.c:456
btrfs_submit_bio+0x50b/0x6d0 fs/btrfs/bio.c:493
btrfs_submit_chunk fs/btrfs/bio.c:745 [inline]
btrfs_submit_bbio+0x5c0/0x19c0 fs/btrfs/bio.c:773
read_extent_buffer_pages+0x5d0/0x8f0 fs/btrfs/extent_io.c:3558
btrfs_read_extent_buffer+0xd8/0x740 fs/btrfs/disk-io.c:229
read_block_for_search+0x5fc/0xb60 fs/btrfs/ctree.c:1619
btrfs_search_slot+0x95f/0x32a0 fs/btrfs/ctree.c:2240
btrfs_init_root_free_objectid+0xf4/0x2a0 fs/btrfs/disk-io.c:4837
btrfs_init_fs_root fs/btrfs/disk-io.c:1137 [inline]
btrfs_get_root_ref+0x646/0xcc0 fs/btrfs/disk-io.c:1364
btrfs_get_fs_root fs/btrfs/disk-io.c:1416 [inline]
open_ctree+0x394d/0x5320 fs/btrfs/disk-io.c:3532
btrfs_fill_super fs/btrfs/super.c:972 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1894 [inline]
btrfs_get_tree+0x11e7/0x1b20 fs/btrfs/super.c:2105
vfs_get_tree+0x92/0x380 fs/super.c:1814
fc_mount+0x16/0xc0 fs/namespace.c:1231
btrfs_get_tree_subvol fs/btrfs/super.c:2068 [inline]
btrfs_get_tree+0xa53/0x1b20 fs/btrfs/super.c:2106
vfs_get_tree+0x92/0x380 fs/super.c:1814
do_new_mount fs/namespace.c:3507 [inline]
path_mount+0x14e6/0x1f20 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount fs/namespace.c:4034 [inline]
__x64_sys_mount+0x294/0x320 fs/namespace.c:4034
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (btrfs-tree-00){++++}-{4:4}:
down_read_nested+0x9e/0x330 kernel/locking/rwsem.c:1649
btrfs_tree_read_lock_nested+0x2f/0x250 fs/btrfs/locking.c:146
btrfs_tree_read_lock fs/btrfs/locking.h:188 [inline]
btrfs_read_lock_root_node+0x6d/0xa0 fs/btrfs/locking.c:267
btrfs_search_slot_get_root fs/btrfs/ctree.c:1790 [inline]
btrfs_search_slot+0x3ba/0x32a0 fs/btrfs/ctree.c:2116
btrfs_del_orphan_item+0xbb/0x180 fs/btrfs/orphan.c:41
btrfs_orphan_del fs/btrfs/inode.c:3472 [inline]
btrfs_evict_inode+0xcd4/0xe90 fs/btrfs/inode.c:5372
evict+0x40c/0x960 fs/inode.c:796
iput_final fs/inode.c:1946 [inline]
iput fs/inode.c:1972 [inline]
iput+0x52a/0x890 fs/inode.c:1958
do_unlinkat+0x5c3/0x760 fs/namei.c:4594
__do_sys_unlink fs/namei.c:4635 [inline]
__se_sys_unlink fs/namei.c:4633 [inline]
__x64_sys_unlink+0xc5/0x110 fs/namei.c:4633
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (btrfs_trans_num_extwriters){++++}-{0:0}:
join_transaction+0x164/0x1010 fs/btrfs/transaction.c:313
start_transaction+0x42c/0x1aa0 fs/btrfs/transaction.c:697
btrfs_dirty_inode+0xc8/0x200 fs/btrfs/inode.c:6055
btrfs_update_time fs/btrfs/inode.c:6089 [inline]
btrfs_update_time+0xb2/0xf0 fs/btrfs/inode.c:6080
inode_update_time fs/inode.c:2124 [inline]
touch_atime+0x352/0x5d0 fs/inode.c:2197
file_accessed include/linux/fs.h:2539 [inline]
filemap_read+0xb91/0xd70 mm/filemap.c:2714
btrfs_file_read_iter+0x17b/0x1c0 fs/btrfs/file.c:3676
__kernel_read+0x3f4/0xb50 fs/read_write.c:523
integrity_kernel_read+0x7f/0xb0 security/integrity/iint.c:28
ima_calc_file_hash_tfm+0x2c9/0x3e0 security/integrity/ima/ima_crypto.c:480
ima_calc_file_shash security/integrity/ima/ima_crypto.c:511 [inline]
ima_calc_file_hash+0x1ba/0x490 security/integrity/ima/ima_crypto.c:568
ima_collect_measurement+0x89f/0xa40 security/integrity/ima/ima_api.c:293
process_measurement+0x1271/0x2370 security/integrity/ima/ima_main.c:372
ima_file_check+0xc6/0x110 security/integrity/ima/ima_main.c:572
security_file_post_open+0x8e/0x210 security/security.c:3121
do_open fs/namei.c:3830 [inline]
path_openat+0x1419/0x2d60 fs/namei.c:3987
do_filp_open+0x20c/0x470 fs/namei.c:4014
do_sys_openat2+0x17a/0x1e0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_openat fs/open.c:1433 [inline]
__se_sys_openat fs/open.c:1428 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1428
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (btrfs_trans_num_writers){++++}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
join_transaction+0x436/0x1010 fs/btrfs/transaction.c:288
start_transaction+0x42c/0x1aa0 fs/btrfs/transaction.c:697
btrfs_finish_one_ordered+0x3c9/0x2200 fs/btrfs/inode.c:3082
btrfs_work_helper+0x225/0xc80 fs/btrfs/async-thread.c:314
process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c4/0x3a0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

other info that might help us debug this:

Chain exists of:
btrfs_trans_num_writers --> &mm->mmap_lock --> sb_internal#4

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
rlock(sb_internal#4);
lock(&mm->mmap_lock);
lock(sb_internal#4);
rlock(btrfs_trans_num_writers);

*** DEADLOCK ***

4 locks held by kworker/u8:11/15834:
#0: ffff88802768c148 ((wq_completion)btrfs-endio-write){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3204
#1: ffffc90002f97d80 ((work_completion)(&work->normal_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3205
#2: ffff888067216588 (btrfs_ordered_extent){++++}-{0:0}, at: btrfs_finish_one_ordered+0x8a0/0x2200 fs/btrfs/inode.c:3047
#3: ffff88801271a610 (sb_internal#4){.+.+}-{0:0}, at: btrfs_finish_one_ordered+0x3c9/0x2200 fs/btrfs/inode.c:3082

stack backtrace:
CPU: 0 UID: 0 PID: 15834 Comm: kworker/u8:11 Not tainted 6.13.0-rc1-syzkaller-00025-gfeffde684ac2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: btrfs-endio-write btrfs_work_helper
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
join_transaction+0x436/0x1010 fs/btrfs/transaction.c:288
start_transaction+0x42c/0x1aa0 fs/btrfs/transaction.c:697
btrfs_finish_one_ordered+0x3c9/0x2200 fs/btrfs/inode.c:3082
btrfs_work_helper+0x225/0xc80 fs/btrfs/async-thread.c:314
process_one_work+0x9c8/0x1ba0 kernel/workqueue.c:3229
process_scheduled_works kernel/workqueue.c:3310 [inline]
worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
kthread+0x2c4/0x3a0 kernel/kthread.c:389
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
</TASK>


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