openvswitch: convert to kvmalloc

Patch series "generic radix trees; drop flex arrays".

This patch (of 7):

There was no real need for this code to be using flexarrays, it's just
implementing a hash table - ideally it would be using rhashtables, but
that conversion would be significantly more complicated.

Link: http://lkml.kernel.org/r/20181217131929.11727-2-kent.overstreet@gmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 39 deletions

diff --git a/net/openvswitch/flow_table.c b/net/openvswitch/flow_table.c
index 80ea2a71852e..cfb0098c9a01 100644
--- a/net/openvswitch/flow_table.c
+++ b/net/openvswitch/flow_table.c
@@ -111,29 +111,6 @@ int ovs_flow_tbl_count(const struct flow_table *table)
         return table->count;
 }
 
-static struct flex_array *alloc_buckets(unsigned int n_buckets)
-{
-        struct flex_array *buckets;
-        int i, err;
-
-        buckets = flex_array_alloc(sizeof(struct hlist_head),
-                                   n_buckets, GFP_KERNEL);
-        if (!buckets)
-                return NULL;
-
-        err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
-        if (err) {
-                flex_array_free(buckets);
-                return NULL;
-        }
-
-        for (i = 0; i < n_buckets; i++)
-                INIT_HLIST_HEAD((struct hlist_head *)
-                                        flex_array_get(buckets, i));
-
-        return buckets;
-}
-
 static void flow_free(struct sw_flow *flow)
 {
         int cpu;
@@ -168,31 +145,30 @@ void ovs_flow_free(struct sw_flow *flow, bool deferred)
                 flow_free(flow);
 }
 
-static void free_buckets(struct flex_array *buckets)
-{
-        flex_array_free(buckets);
-}
-
-
 static void __table_instance_destroy(struct table_instance *ti)
 {
-        free_buckets(ti->buckets);
+        kvfree(ti->buckets);
         kfree(ti);
 }
 
 static struct table_instance *table_instance_alloc(int new_size)
 {
         struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+        int i;
 
         if (!ti)
                 return NULL;
 
-        ti->buckets = alloc_buckets(new_size);
-
+        ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
+                                     GFP_KERNEL);
         if (!ti->buckets) {
                 kfree(ti);
                 return NULL;
         }
+
+        for (i = 0; i < new_size; i++)
+                INIT_HLIST_HEAD(&ti->buckets[i]);
+
         ti->n_buckets = new_size;
         ti->node_ver = 0;
         ti->keep_flows = false;
@@ -249,7 +225,7 @@ static void table_instance_destroy(struct table_instance *ti,
 
         for (i = 0; i < ti->n_buckets; i++) {
                 struct sw_flow *flow;
-                struct hlist_head *head = flex_array_get(ti->buckets, i);
+                struct hlist_head *head = &ti->buckets[i];
                 struct hlist_node *n;
                 int ver = ti->node_ver;
                 int ufid_ver = ufid_ti->node_ver;
@@ -294,7 +270,7 @@ struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
         ver = ti->node_ver;
         while (*bucket < ti->n_buckets) {
                 i = 0;
-                head = flex_array_get(ti->buckets, *bucket);
+                head = &ti->buckets[*bucket];
                 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
                         if (i < *last) {
                                 i++;
@@ -313,8 +289,7 @@ struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
 static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
 {
         hash = jhash_1word(hash, ti->hash_seed);
-        return flex_array_get(ti->buckets,
-                                (hash & (ti->n_buckets - 1)));
+        return &ti->buckets[hash & (ti->n_buckets - 1)];
 }
 
 static void table_instance_insert(struct table_instance *ti,
@@ -347,9 +322,7 @@ static void flow_table_copy_flows(struct table_instance *old,
         /* Insert in new table. */
         for (i = 0; i < old->n_buckets; i++) {
                 struct sw_flow *flow;
-                struct hlist_head *head;
-
-                head = flex_array_get(old->buckets, i);
+                struct hlist_head *head = &old->buckets[i];
 
                 if (ufid)
                         hlist_for_each_entry(flow, head,