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| author | Kent Overstreet <kent.overstreet@linux.dev> | 2023-06-19 07:07:40 +0300 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-10-23 00:10:04 +0300 |
| commit | 6547ebabdaac4407ccc978f63f4dc4d9f8936783 (patch) | |
| tree | e13ce30c6744dbf2281dd4368b2f7c93352a2636 /fs/bcachefs/sysfs.c | |
| parent | e96f5a61cb8008a1acae9a14cc9d382554da60b4 (diff) | |
| download | linux-6547ebabdaac4407ccc978f63f4dc4d9f8936783.tar.xz | |
bcachefs: Don't call lock_graph_descend() with wait lock held
This fixes a deadlock:
01305 WARNING: possible circular locking dependency detected
01305 6.3.0-ktest-gf4de9bee61af #5305 Tainted: G W
01305 ------------------------------------------------------
01305 cat/14658 is trying to acquire lock:
01305 ffffffc00982f460 (fs_reclaim){+.+.}-{0:0}, at: __kmem_cache_alloc_node+0x48/0x278
01305
01305 but task is already holding lock:
01305 ffffff8011aaf040 (&lock->wait_lock){+.+.}-{2:2}, at: bch2_check_for_deadlock+0x4b8/0xa58
01305
01305 which lock already depends on the new lock.
01305
01305
01305 the existing dependency chain (in reverse order) is:
01305
01305 -> #2 (&lock->wait_lock){+.+.}-{2:2}:
01305 _raw_spin_lock+0x54/0x70
01305 __six_lock_wakeup+0x40/0x1b0
01305 six_unlock_ip+0xe8/0x248
01305 bch2_btree_key_cache_scan+0x720/0x940
01305 shrink_slab.constprop.0+0x284/0x770
01305 shrink_node+0x390/0x828
01305 balance_pgdat+0x390/0x6d0
01305 kswapd+0x2e4/0x718
01305 kthread+0x184/0x1a8
01305 ret_from_fork+0x10/0x20
01305
01305 -> #1 (&c->lock#2){+.+.}-{3:3}:
01305 __mutex_lock+0x104/0x14a0
01305 mutex_lock_nested+0x30/0x40
01305 bch2_btree_key_cache_scan+0x5c/0x940
01305 shrink_slab.constprop.0+0x284/0x770
01305 shrink_node+0x390/0x828
01305 balance_pgdat+0x390/0x6d0
01305 kswapd+0x2e4/0x718
01305 kthread+0x184/0x1a8
01305 ret_from_fork+0x10/0x20
01305
01305 -> #0 (fs_reclaim){+.+.}-{0:0}:
01305 __lock_acquire+0x19d0/0x2930
01305 lock_acquire+0x1dc/0x458
01305 fs_reclaim_acquire+0x9c/0xe0
01305 __kmem_cache_alloc_node+0x48/0x278
01305 __kmalloc_node_track_caller+0x5c/0x278
01305 krealloc+0x94/0x180
01305 bch2_printbuf_make_room.part.0+0xac/0x118
01305 bch2_prt_printf+0x150/0x1e8
01305 bch2_btree_bkey_cached_common_to_text+0x170/0x298
01305 bch2_btree_trans_to_text+0x244/0x348
01305 print_cycle+0x7c/0xb0
01305 break_cycle+0x254/0x528
01305 bch2_check_for_deadlock+0x59c/0xa58
01305 bch2_btree_deadlock_read+0x174/0x200
01305 full_proxy_read+0x94/0xf0
01305 vfs_read+0x15c/0x3a8
01305 ksys_read+0xb8/0x148
01305 __arm64_sys_read+0x48/0x60
01305 invoke_syscall.constprop.0+0x64/0x138
01305 do_el0_svc+0x84/0x138
01305 el0_svc+0x34/0x80
01305 el0t_64_sync_handler+0xb0/0xb8
01305 el0t_64_sync+0x14c/0x150
01305
01305 other info that might help us debug this:
01305
01305 Chain exists of:
01305 fs_reclaim --> &c->lock#2 --> &lock->wait_lock
01305
01305 Possible unsafe locking scenario:
01305
01305 CPU0 CPU1
01305 ---- ----
01305 lock(&lock->wait_lock);
01305 lock(&c->lock#2);
01305 lock(&lock->wait_lock);
01305 lock(fs_reclaim);
01305
01305 *** DEADLOCK ***
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'fs/bcachefs/sysfs.c')
0 files changed, 0 insertions, 0 deletions