From: Bobby Eshleman bobbyeshleman@meta.com
Refactor sock_devmem_dontneed() in preparation for supporting both autorelease and manual token release modes.
Split the function into two parts: - sock_devmem_dontneed(): handles input validation, token allocation, and copying from userspace - sock_devmem_dontneed_autorelease(): performs the actual token release via xarray lookup and page pool put
This separation allows a future commit to add a parallel sock_devmem_dontneed_manual_release() function that uses a different token tracking mechanism (per-niov reference counting) without duplicating the input validation logic.
The refactoring is purely mechanical with no functional change. Only intended to minimize the noise in subsequent patches.
Reviewed-by: Mina Almasry almasrymina@google.com Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- net/core/sock.c | 52 ++++++++++++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 20 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c index 7a9bbc2afcf0..5562f517d889 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1082,30 +1082,13 @@ static int sock_reserve_memory(struct sock *sk, int bytes) #define MAX_DONTNEED_FRAGS 1024
static noinline_for_stack int -sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) +sock_devmem_dontneed_autorelease(struct sock *sk, struct dmabuf_token *tokens, + unsigned int num_tokens) { - unsigned int num_tokens, i, j, k, netmem_num = 0; - struct dmabuf_token *tokens; + unsigned int i, j, k, netmem_num = 0; int ret = 0, num_frags = 0; netmem_ref netmems[16];
- if (!sk_is_tcp(sk)) - return -EBADF; - - if (optlen % sizeof(*tokens) || - optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS) - return -EINVAL; - - num_tokens = optlen / sizeof(*tokens); - tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL); - if (!tokens) - return -ENOMEM; - - if (copy_from_sockptr(tokens, optval, optlen)) { - kvfree(tokens); - return -EFAULT; - } - xa_lock_bh(&sk->sk_user_frags); for (i = 0; i < num_tokens; i++) { for (j = 0; j < tokens[i].token_count; j++) { @@ -1135,6 +1118,35 @@ sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) for (k = 0; k < netmem_num; k++) WARN_ON_ONCE(!napi_pp_put_page(netmems[k]));
+ return ret; +} + +static noinline_for_stack int +sock_devmem_dontneed(struct sock *sk, sockptr_t optval, unsigned int optlen) +{ + struct dmabuf_token *tokens; + unsigned int num_tokens; + int ret; + + if (!sk_is_tcp(sk)) + return -EBADF; + + if (optlen % sizeof(*tokens) || + optlen > sizeof(*tokens) * MAX_DONTNEED_TOKENS) + return -EINVAL; + + num_tokens = optlen / sizeof(*tokens); + tokens = kvmalloc_array(num_tokens, sizeof(*tokens), GFP_KERNEL); + if (!tokens) + return -ENOMEM; + + if (copy_from_sockptr(tokens, optval, optlen)) { + kvfree(tokens); + return -EFAULT; + } + + ret = sock_devmem_dontneed_autorelease(sk, tokens, num_tokens); + kvfree(tokens); return ret; }