packet: switch kvzalloc to allocate memory

The patches includes following change:

*Use modern kvzalloc()/kvfree() instead of custom allocations.

*Remove order argument for alloc_pg_vec, it can get from req.

*Remove order argument for free_pg_vec, free_pg_vec now uses
kvfree which does not need order argument.

*Remove pg_vec_order from struct packet_ring_buffer, no longer
need to save/restore 'order'

*Remove variable 'order' for packet_set_ring, it is now unused

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 13 insertions, 32 deletions

diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 75c92a87e7b2..5610061e7f2e 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -4137,52 +4137,36 @@ static const struct vm_operations_struct packet_mmap_ops = {
         .close  =       packet_mm_close,
 };
 
-static void free_pg_vec(struct pgv *pg_vec, unsigned int order,
-                        unsigned int len)
+static void free_pg_vec(struct pgv *pg_vec, unsigned int len)
 {
         int i;
 
         for (i = 0; i < len; i++) {
                 if (likely(pg_vec[i].buffer)) {
-                        if (is_vmalloc_addr(pg_vec[i].buffer))
-                                vfree(pg_vec[i].buffer);
-                        else
-                                free_pages((unsigned long)pg_vec[i].buffer,
-                                           order);
+                        kvfree(pg_vec[i].buffer);
                         pg_vec[i].buffer = NULL;
                 }
         }
         kfree(pg_vec);
 }
 
-static char *alloc_one_pg_vec_page(unsigned long order)
+static char *alloc_one_pg_vec_page(unsigned long size)
 {
         char *buffer;
-        gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP |
-                          __GFP_ZERO | __GFP_NOWARN | __GFP_NORETRY;
 
-        buffer = (char *) __get_free_pages(gfp_flags, order);
+        buffer = kvzalloc(size, GFP_KERNEL);
         if (buffer)
                 return buffer;
 
-        /* __get_free_pages failed, fall back to vmalloc */
-        buffer = vzalloc(array_size((1 << order), PAGE_SIZE));
-        if (buffer)
-                return buffer;
+        buffer = kvzalloc(size, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
 
-        /* vmalloc failed, lets dig into swap here */
-        gfp_flags &= ~__GFP_NORETRY;
-        buffer = (char *) __get_free_pages(gfp_flags, order);
-        if (buffer)
-                return buffer;
-
-        /* complete and utter failure */
-        return NULL;
+        return buffer;
 }
 
-static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
+static struct pgv *alloc_pg_vec(struct tpacket_req *req)
 {
         unsigned int block_nr = req->tp_block_nr;
+        unsigned long size = req->tp_block_size;
         struct pgv *pg_vec;
         int i;
 
@@ -4191,7 +4175,7 @@ static struct pgv *alloc_pg_vec(struct tpacket_req *req, int order)
                 goto out;
 
         for (i = 0; i < block_nr; i++) {
-                pg_vec[i].buffer = alloc_one_pg_vec_page(order);
+                pg_vec[i].buffer = alloc_one_pg_vec_page(size);
                 if (unlikely(!pg_vec[i].buffer))
                         goto out_free_pgvec;
         }
@@ -4200,7 +4184,7 @@ out:
         return pg_vec;
 
 out_free_pgvec:
-        free_pg_vec(pg_vec, order, block_nr);
+        free_pg_vec(pg_vec, block_nr);
         pg_vec = NULL;
         goto out;
 }
@@ -4210,9 +4194,9 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
 {
         struct pgv *pg_vec = NULL;
         struct packet_sock *po = pkt_sk(sk);
-        int was_running, order = 0;
         struct packet_ring_buffer *rb;
         struct sk_buff_head *rb_queue;
+        int was_running;
         __be16 num;
         int err = -EINVAL;
         /* Added to avoid minimal code churn */
@@ -4274,8 +4258,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
                         goto out;
 
                 err = -ENOMEM;
-                order = get_order(req->tp_block_size);
-                pg_vec = alloc_pg_vec(req, order);
+                pg_vec = alloc_pg_vec(req);
                 if (unlikely(!pg_vec))
                         goto out;
                 switch (po->tp_version) {
@@ -4329,7 +4312,6 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
                 rb->frame_size = req->tp_frame_size;
                 spin_unlock_bh(&rb_queue->lock);
 
-                swap(rb->pg_vec_order, order);
                 swap(rb->pg_vec_len, req->tp_block_nr);
 
                 rb->pg_vec_pages = req->tp_block_size/PAGE_SIZE;
@@ -4355,7 +4337,7 @@ static int packet_set_ring(struct sock *sk, union tpacket_req_u *req_u,
         }
 
         if (pg_vec)
-                free_pg_vec(pg_vec, order, req->tp_block_nr);
+                free_pg_vec(pg_vec, req->tp_block_nr);
 out:
         return err;
 }
diff --git a/net/packet/internal.h b/net/packet/internal.h
index 3bb7c5fb3bff..8f50036f62f0 100644
--- a/net/packet/internal.h
+++ b/net/packet/internal.h
@@ -64,7 +64,6 @@ struct packet_ring_buffer {
         unsigned int            frame_size;
         unsigned int            frame_max;
 
-        unsigned int            pg_vec_order;
         unsigned int            pg_vec_pages;
         unsigned int            pg_vec_len;