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[AF_PACKET]: Convert PACKET_MMAP over to vm_insert_page().
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So we can properly use __GFP_COMP and avoid the use of
PG_reserved pages.

With extremely helpful review from Hugh Dickins.

Signed-off-by: David S. Miller <[email protected]>
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David S. Miller committed Dec 7, 2005
1 parent dfb4b9d commit 4ebf0ae
Showing 1 changed file with 61 additions and 54 deletions.
115 changes: 61 additions & 54 deletions net/packet/af_packet.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1587,23 +1587,47 @@ static inline struct page *pg_vec_endpage(char *one_pg_vec, unsigned int order)
return virt_to_page(one_pg_vec + (PAGE_SIZE << order) - 1);
}

static void free_pg_vec(char **pg_vec, unsigned order, unsigned len)
static void free_pg_vec(char **pg_vec, unsigned int order, unsigned int len)
{
int i;

for (i=0; i<len; i++) {
if (pg_vec[i]) {
struct page *page, *pend;

pend = pg_vec_endpage(pg_vec[i], order);
for (page = virt_to_page(pg_vec[i]); page <= pend; page++)
ClearPageReserved(page);
free_pages((unsigned long)pg_vec[i], order);
}
for (i = 0; i < len; i++) {
if (likely(pg_vec[i]))
free_pages((unsigned long) pg_vec[i], order);
}
kfree(pg_vec);
}

static inline char *alloc_one_pg_vec_page(unsigned long order)
{
return (char *) __get_free_pages(GFP_KERNEL | __GFP_COMP | __GFP_ZERO,
order);
}

static char **alloc_pg_vec(struct tpacket_req *req, int order)
{
unsigned int block_nr = req->tp_block_nr;
char **pg_vec;
int i;

pg_vec = kzalloc(block_nr * sizeof(char *), GFP_KERNEL);
if (unlikely(!pg_vec))
goto out;

for (i = 0; i < block_nr; i++) {
pg_vec[i] = alloc_one_pg_vec_page(order);
if (unlikely(!pg_vec[i]))
goto out_free_pgvec;
}

out:
return pg_vec;

out_free_pgvec:
free_pg_vec(pg_vec, order, block_nr);
pg_vec = NULL;
goto out;
}

static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing)
{
Expand All @@ -1617,64 +1641,46 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing

/* Sanity tests and some calculations */

if (po->pg_vec)
if (unlikely(po->pg_vec))
return -EBUSY;

if ((int)req->tp_block_size <= 0)
if (unlikely((int)req->tp_block_size <= 0))
return -EINVAL;
if (req->tp_block_size&(PAGE_SIZE-1))
if (unlikely(req->tp_block_size & (PAGE_SIZE - 1)))
return -EINVAL;
if (req->tp_frame_size < TPACKET_HDRLEN)
if (unlikely(req->tp_frame_size < TPACKET_HDRLEN))
return -EINVAL;
if (req->tp_frame_size&(TPACKET_ALIGNMENT-1))
if (unlikely(req->tp_frame_size & (TPACKET_ALIGNMENT - 1)))
return -EINVAL;

po->frames_per_block = req->tp_block_size/req->tp_frame_size;
if (po->frames_per_block <= 0)
if (unlikely(po->frames_per_block <= 0))
return -EINVAL;
if (po->frames_per_block*req->tp_block_nr != req->tp_frame_nr)
if (unlikely((po->frames_per_block * req->tp_block_nr) !=
req->tp_frame_nr))
return -EINVAL;
/* OK! */

/* Allocate page vector */
while ((PAGE_SIZE<<order) < req->tp_block_size)
order++;

err = -ENOMEM;

pg_vec = kmalloc(req->tp_block_nr*sizeof(char *), GFP_KERNEL);
if (pg_vec == NULL)
order = get_order(req->tp_block_size);
pg_vec = alloc_pg_vec(req, order);
if (unlikely(!pg_vec))
goto out;
memset(pg_vec, 0, req->tp_block_nr*sizeof(char **));

for (i=0; i<req->tp_block_nr; i++) {
struct page *page, *pend;
pg_vec[i] = (char *)__get_free_pages(GFP_KERNEL, order);
if (!pg_vec[i])
goto out_free_pgvec;

pend = pg_vec_endpage(pg_vec[i], order);
for (page = virt_to_page(pg_vec[i]); page <= pend; page++)
SetPageReserved(page);
}
/* Page vector is allocated */

l = 0;
for (i=0; i<req->tp_block_nr; i++) {
for (i = 0; i < req->tp_block_nr; i++) {
char *ptr = pg_vec[i];
struct tpacket_hdr *header;
int k;

for (k=0; k<po->frames_per_block; k++) {

header = (struct tpacket_hdr*)ptr;
for (k = 0; k < po->frames_per_block; k++) {
header = (struct tpacket_hdr *) ptr;
header->tp_status = TP_STATUS_KERNEL;
ptr += req->tp_frame_size;
}
}
/* Done */
} else {
if (req->tp_frame_nr)
if (unlikely(req->tp_frame_nr))
return -EINVAL;
}

Expand All @@ -1701,7 +1707,7 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing

spin_lock_bh(&sk->sk_receive_queue.lock);
pg_vec = XC(po->pg_vec, pg_vec);
po->frame_max = req->tp_frame_nr-1;
po->frame_max = (req->tp_frame_nr - 1);
po->head = 0;
po->frame_size = req->tp_frame_size;
spin_unlock_bh(&sk->sk_receive_queue.lock);
Expand All @@ -1728,7 +1734,6 @@ static int packet_set_ring(struct sock *sk, struct tpacket_req *req, int closing

release_sock(sk);

out_free_pgvec:
if (pg_vec)
free_pg_vec(pg_vec, order, req->tp_block_nr);
out:
Expand All @@ -1755,17 +1760,19 @@ static int packet_mmap(struct file *file, struct socket *sock, struct vm_area_st
if (size != po->pg_vec_len*po->pg_vec_pages*PAGE_SIZE)
goto out;

atomic_inc(&po->mapped);
start = vma->vm_start;
err = -EAGAIN;
for (i=0; i<po->pg_vec_len; i++) {
if (remap_pfn_range(vma, start,
__pa(po->pg_vec[i]) >> PAGE_SHIFT,
po->pg_vec_pages*PAGE_SIZE,
vma->vm_page_prot))
goto out;
start += po->pg_vec_pages*PAGE_SIZE;
for (i = 0; i < po->pg_vec_len; i++) {
struct page *page = virt_to_page(po->pg_vec[i]);
int pg_num;

for (pg_num = 0; pg_num < po->pg_vec_pages; pg_num++, page++) {
err = vm_insert_page(vma, start, page);
if (unlikely(err))
goto out;
start += PAGE_SIZE;
}
}
atomic_inc(&po->mapped);
vma->vm_ops = &packet_mmap_ops;
err = 0;

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