[PATCH] mm/vmalloc: Remove WARN_ON_ONCE related to adjust_va_to_fit_type

[Jaeseon Sim]

There's panic issue as follows when do alloc_vmap_area:

Kernel panic - not syncing: kernel: panic_on_warn set ...

page allocation failure: order:0, mode:0x800(GFP_NOWAIT)
Call Trace:
warn_alloc+0xf4/0x190
__alloc_pages_slowpath+0xe0c/0xffc
__alloc_pages+0x250/0x2d0
new_slab+0x17c/0x4e0
___slab_alloc+0x4e4/0x8a8
__slab_alloc+0x34/0x6c
kmem_cache_alloc+0x20c/0x2f0
adjust_va_to_fit_type
__alloc_vmap_area
alloc_vmap_area+0x298/0x7fc
__get_vm_area_node+0x10c/0x1b4
__vmalloc_node_range+0x19c/0x7c0

Commit 1b23ff80b399 ("mm/vmalloc: invoke classify_va_fit_type() in
adjust_va_to_fit_type()") moved classify_va_fit_type() into
adjust_va_to_fit_type() and used WARN_ON_ONCE() to handle return
value of adjust_va_to_fit_type(), just as classify_va_fit_type()
was handled.

There is another path in adjust_va_to_fit_type() which could
return failure and will be handled in alloc_vmap_area().
Remove WARN_ON_ONCE() for this case.

Fixes: 45c62fc2897d ("mm/vmalloc: Remove WARN_ON_ONCE related to adjust_va_to_fit_type")
Signed-off-by: Jaeseon Sim <jason.sim@xxxxxxxxxxx>
---
 mm/vmalloc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ef8599d394fd..4a82b6525d48 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1522,7 +1522,7 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
 
         /* Update the free vmap_area. */
         ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
-        if (WARN_ON_ONCE(ret))
+        if (ret)
                 return vend;
 
 #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
@@ -4143,7 +4143,7 @@ struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
                 ret = adjust_va_to_fit_type(&free_vmap_area_root,
                                             &free_vmap_area_list,
                                             va, start, size);
-                if (WARN_ON_ONCE(unlikely(ret)))
+                if (unlikely(ret))
                         /* It is a BUG(), but trigger recovery instead. */
                         goto recovery;
 
-- 
2.17.1