dlm: fix up memory allocation flags

Use ls_allocation for memory allocations, which a cluster fs sets to
GFP_NOFS. Use GFP_NOFS for allocations when no lockspace struct is
available. Taking dlm locks needs to avoid calling back into the
cluster fs because write-out can require taking dlm locks.

Cc: Christine Caulfield <[e-mail]>
Signed-off-by: Steven Whitehouse <[e-mail]>
Signed-off-by: David Teigland <[e-mail]>

fs/dlm/lowcomms.c

···
 	con->sock->sk->sk_write_space = lowcomms_write_space;
 	con->sock->sk->sk_state_change = lowcomms_state_change;
 	con->sock->sk->sk_user_data = con;
+	con->sock->sk->sk_allocation = GFP_NOFS;
 	return 0;
 }
 

fs/dlm/memory.c

···
 {
 	char *p;
 
-	p = kzalloc(ls->ls_lvblen, GFP_KERNEL);
+	p = kzalloc(ls->ls_lvblen, ls->ls_allocation);
 	return p;
 }
 
···
 
 	DLM_ASSERT(namelen <= DLM_RESNAME_MAXLEN,);
 
-	r = kzalloc(sizeof(*r) + namelen, GFP_KERNEL);
+	r = kzalloc(sizeof(*r) + namelen, ls->ls_allocation);
 	return r;
 }
 
···
 {
 	struct dlm_lkb *lkb;
 
-	lkb = kmem_cache_zalloc(lkb_cache, GFP_KERNEL);
+	lkb = kmem_cache_zalloc(lkb_cache, ls->ls_allocation);
 	return lkb;
 }
 

fs/dlm/midcomms.c

···
 		   ordinary messages). */
 
 		if (msglen > sizeof(__tmp) && p == &__tmp.p) {
-			p = kmalloc(dlm_config.ci_buffer_size, GFP_KERNEL);
+			p = kmalloc(dlm_config.ci_buffer_size, GFP_NOFS);
 			if (p == NULL)
 				return ret;
 		}