diff options
| author | Eric Dumazet <edumazet@google.com> | 2014-10-10 04:48:17 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-10-10 15:37:28 -0400 |
| commit | 98226208c8a1fe5834e92d827a2a1e8051a17943 (patch) | |
| tree | 09bc0b1ebf516dcba2d21b93d98dc0e3d2bc3181 | |
| parent | ec91698360b3818ff426488a1529811f7a7ab87f (diff) | |
| download | linux-98226208c8a1fe5834e92d827a2a1e8051a17943.tar.bz2 | |
mlx4: fix race accessing page->_count
This is illegal to use atomic_set(&page->_count, ...) even if we 'own'
the page. Other entities in the kernel need to use get_page_unless_zero()
to get a reference to the page before testing page properties, so we could
loose a refcount increment.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_rx.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c b/drivers/net/ethernet/mellanox/mlx4/en_rx.c index a33048ee9621..01660c595f5c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c @@ -76,10 +76,10 @@ static int mlx4_alloc_pages(struct mlx4_en_priv *priv, page_alloc->dma = dma; page_alloc->page_offset = frag_info->frag_align; /* Not doing get_page() for each frag is a big win - * on asymetric workloads. + * on asymetric workloads. Note we can not use atomic_set(). */ - atomic_set(&page->_count, - page_alloc->page_size / frag_info->frag_stride); + atomic_add(page_alloc->page_size / frag_info->frag_stride - 1, + &page->_count); return 0; } |