treewide: use kv[mz]alloc* rather than opencoded variants

There are many code paths opencoding kvmalloc.  Let's use the helper
instead.  The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator.  E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation.  This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously.  There is no guarantee something like that happens
though.

This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Michal Hocko <[email protected]>
Reviewed-by: Boris Ostrovsky <[email protected]> # Xen bits
Acked-by: Kees Cook <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Acked-by: Andreas Dilger <[email protected]> # Lustre
Acked-by: Christian Borntraeger <[email protected]> # KVM/s390
Acked-by: Dan Williams <[email protected]> # nvdim
Acked-by: David Sterba <[email protected]> # btrfs
Acked-by: Ilya Dryomov <[email protected]> # Ceph
Acked-by: Tariq Toukan <[email protected]> # mlx4
Acked-by: Leon Romanovsky <[email protected]> # mlx5
Cc: Martin Schwidefsky <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Herbert Xu <[email protected]>
Cc: Anton Vorontsov <[email protected]>
Cc: Colin Cross <[email protected]>
Cc: Tony Luck <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Ben Skeggs <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: Santosh Raspatur <[email protected]>
Cc: Hariprasad S <[email protected]>
Cc: Yishai Hadas <[email protected]>
Cc: Oleg Drokin <[email protected]>
Cc: "Yan, Zheng" <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: David Miller <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

crypto/lzo.c

@@ -32,9 +32,7 @@ static void *lzo_alloc_ctx(struct crypto_scomp *tfm)
 {
 	void *ctx;
 
-	ctx = kmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL | __GFP_NOWARN);
-	if (!ctx)
-		ctx = vmalloc(LZO1X_MEM_COMPRESS);
+	ctx = kvmalloc(LZO1X_MEM_COMPRESS, GFP_KERNEL);
 	if (!ctx)
 		return ERR_PTR(-ENOMEM);