lib/rhashtable: simplify bucket_table_alloc()

As of ce91f6ee5b3b ("mm: kvmalloc does not fallback to vmalloc for
incompatible gfp flags") we can simplify the caller and trust kvzalloc()
to just do the right thing.  For the case of the GFP_ATOMIC context, we
can drop the __GFP_NORETRY flag for obvious reasons, and for the
__GFP_NOWARN case, however, it is changed such that the caller passes the
flag instead of making bucket_table_alloc() handle it.

This slightly changes the gfp flags passed on to nested_table_alloc() as
it will now also use GFP_ATOMIC | __GFP_NOWARN.  However, I consider this
a positive consequence as for the same reasons we want nowarn semantics in
bucket_table_alloc().

[manfred@colorfullife.com: commit id extended to 12 digits, line wraps updated]
Link: http://lkml.kernel.org/r/20180712185241.4017-8-manfred@colorfullife.com
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 5 deletions

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index ae4223e0f5bc..238c8daa9852 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -174,10 +174,7 @@ static struct bucket_table *bucket_table_alloc(struct rhashtable *ht,
         int i;
 
         size = sizeof(*tbl) + nbuckets * sizeof(tbl->buckets[0]);
-        if (gfp != GFP_KERNEL)
-                tbl = kzalloc(size, gfp | __GFP_NOWARN | __GFP_NORETRY);
-        else
-                tbl = kvzalloc(size, gfp);
+        tbl = kvzalloc(size, gfp);
 
         size = nbuckets;
 
@@ -450,7 +447,7 @@ static int rhashtable_insert_rehash(struct rhashtable *ht,
 
         err = -ENOMEM;
 
-        new_tbl = bucket_table_alloc(ht, size, GFP_ATOMIC);
+        new_tbl = bucket_table_alloc(ht, size, GFP_ATOMIC | __GFP_NOWARN);
         if (new_tbl == NULL)
                 goto fail;