slab_pre_alloc_hook() strips __GFP_NOLOCKDEP away.

[Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>]

Run into
| ======================================================
| WARNING: possible circular locking dependency detected
| 5.17.0-next-20220322 #19 Not tainted
| ------------------------------------------------------
| kswapd1/513 is trying to acquire lock:
| ffff888555b7e628 (&xfs_dir_ilock_class){++++}-{3:3}, at: xfs_icwalk_ag+0x36c/0x810
| 
| but task is already holding lock:
| ffffffff82a2fb20 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x600/0x740
| 
| which lock already depends on the new lock.
| 
| 
| the existing dependency chain (in reverse order) is:
| 
| -> #1 (fs_reclaim){+.+.}-{0:0}:
|        fs_reclaim_acquire+0xaa/0xe0
|        __kmalloc_node+0x65/0x3e0
|        xfs_attr_copy_value+0x70/0xa0
…

and I think this is similar to commit
   704687deaae76 ("mm: make slab and vmalloc allocators __GFP_NOLOCKDEP aware")

and maybe something like this:

diff --git a/mm/slab.h b/mm/slab.h
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -717,7 +717,7 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 						     struct obj_cgroup **objcgp,
 						     size_t size, gfp_t flags)
 {
-	flags &= gfp_allowed_mask;
+	flags &= gfp_allowed_mask | __GFP_NOLOCKDEP;
 
 	might_alloc(flags);
 
?

Sebastian