mm, mempool: do not allow atomic resizing

Allocating a large number of elements in atomic context could quickly
deplete memory reserves, so just disallow atomic resizing entirely.

Nothing currently uses mempool_resize() with anything other than
GFP_KERNEL, so convert existing callers to drop the gfp_mask.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Steffen Maier <maier@linux.vnet.ibm.com>	[zfcp]
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Steve French <sfrench@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 480cf9c..f3bfe08 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -773,8 +773,7 @@
 
 	length = atomic_dec_return(&tcpSesAllocCount);
 	if (length > 0)
-		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
-				GFP_KERNEL);
+		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 }
 
 static int
@@ -848,8 +847,7 @@
 
 	length = atomic_inc_return(&tcpSesAllocCount);
 	if (length > 1)
-		mempool_resize(cifs_req_poolp, length + cifs_min_rcv,
-				GFP_KERNEL);
+		mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 
 	set_freezable();
 	while (server->tcpStatus != CifsExiting) {