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skbuff: move __alloc_skb() next to the other skb allocation functions
In preparation before reusing several functions in all three skb allocation variants, move __alloc_skb() next to the __netdev_alloc_skb() and __napi_alloc_skb(). No functional changes. Signed-off-by: Alexander Lobakin <alobakin@pm.me> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexander Lobakin
David S. Miller
parent
773dc50d71
commit
5381b23d5b
@ -119,148 +119,6 @@ static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr)
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skb_panic(skb, sz, addr, __func__);
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}
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/*
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* kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells
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* the caller if emergency pfmemalloc reserves are being used. If it is and
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* the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves
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* may be used. Otherwise, the packet data may be discarded until enough
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* memory is free
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*/
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#define kmalloc_reserve(size, gfp, node, pfmemalloc) \
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__kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc)
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static void *__kmalloc_reserve(size_t size, gfp_t flags, int node,
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unsigned long ip, bool *pfmemalloc)
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{
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void *obj;
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bool ret_pfmemalloc = false;
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/*
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* Try a regular allocation, when that fails and we're not entitled
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* to the reserves, fail.
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*/
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obj = kmalloc_node_track_caller(size,
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flags | __GFP_NOMEMALLOC | __GFP_NOWARN,
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node);
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if (obj || !(gfp_pfmemalloc_allowed(flags)))
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goto out;
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/* Try again but now we are using pfmemalloc reserves */
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ret_pfmemalloc = true;
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obj = kmalloc_node_track_caller(size, flags, node);
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out:
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if (pfmemalloc)
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*pfmemalloc = ret_pfmemalloc;
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return obj;
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}
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/* Allocate a new skbuff. We do this ourselves so we can fill in a few
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* 'private' fields and also do memory statistics to find all the
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* [BEEP] leaks.
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*
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*/
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/**
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* __alloc_skb - allocate a network buffer
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* @size: size to allocate
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* @gfp_mask: allocation mask
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* @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache
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* instead of head cache and allocate a cloned (child) skb.
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* If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for
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* allocations in case the data is required for writeback
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* @node: numa node to allocate memory on
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*
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* Allocate a new &sk_buff. The returned buffer has no headroom and a
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* tail room of at least size bytes. The object has a reference count
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* of one. The return is the buffer. On a failure the return is %NULL.
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*
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* Buffers may only be allocated from interrupts using a @gfp_mask of
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* %GFP_ATOMIC.
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*/
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struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
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int flags, int node)
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{
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struct kmem_cache *cache;
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struct skb_shared_info *shinfo;
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struct sk_buff *skb;
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u8 *data;
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bool pfmemalloc;
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cache = (flags & SKB_ALLOC_FCLONE)
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? skbuff_fclone_cache : skbuff_head_cache;
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if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX))
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gfp_mask |= __GFP_MEMALLOC;
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/* Get the HEAD */
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skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
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if (!skb)
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goto out;
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prefetchw(skb);
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/* We do our best to align skb_shared_info on a separate cache
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* line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives
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* aligned memory blocks, unless SLUB/SLAB debug is enabled.
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* Both skb->head and skb_shared_info are cache line aligned.
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*/
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size = SKB_DATA_ALIGN(size);
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size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc);
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if (!data)
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goto nodata;
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/* kmalloc(size) might give us more room than requested.
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* Put skb_shared_info exactly at the end of allocated zone,
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* to allow max possible filling before reallocation.
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*/
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size = SKB_WITH_OVERHEAD(ksize(data));
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prefetchw(data + size);
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/*
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* Only clear those fields we need to clear, not those that we will
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* actually initialise below. Hence, don't put any more fields after
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* the tail pointer in struct sk_buff!
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*/
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memset(skb, 0, offsetof(struct sk_buff, tail));
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/* Account for allocated memory : skb + skb->head */
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skb->truesize = SKB_TRUESIZE(size);
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skb->pfmemalloc = pfmemalloc;
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refcount_set(&skb->users, 1);
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skb->head = data;
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skb->data = data;
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skb_reset_tail_pointer(skb);
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skb->end = skb->tail + size;
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skb->mac_header = (typeof(skb->mac_header))~0U;
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skb->transport_header = (typeof(skb->transport_header))~0U;
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/* make sure we initialize shinfo sequentially */
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shinfo = skb_shinfo(skb);
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
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atomic_set(&shinfo->dataref, 1);
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if (flags & SKB_ALLOC_FCLONE) {
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struct sk_buff_fclones *fclones;
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fclones = container_of(skb, struct sk_buff_fclones, skb1);
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skb->fclone = SKB_FCLONE_ORIG;
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refcount_set(&fclones->fclone_ref, 1);
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fclones->skb2.fclone = SKB_FCLONE_CLONE;
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}
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skb_set_kcov_handle(skb, kcov_common_handle());
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out:
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return skb;
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nodata:
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kmem_cache_free(cache, skb);
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skb = NULL;
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goto out;
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}
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EXPORT_SYMBOL(__alloc_skb);
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/* Caller must provide SKB that is memset cleared */
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static struct sk_buff *__build_skb_around(struct sk_buff *skb,
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void *data, unsigned int frag_size)
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@ -408,6 +266,148 @@ void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask)
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}
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EXPORT_SYMBOL(__netdev_alloc_frag_align);
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/*
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* kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells
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* the caller if emergency pfmemalloc reserves are being used. If it is and
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* the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves
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* may be used. Otherwise, the packet data may be discarded until enough
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* memory is free
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*/
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#define kmalloc_reserve(size, gfp, node, pfmemalloc) \
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__kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc)
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static void *__kmalloc_reserve(size_t size, gfp_t flags, int node,
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unsigned long ip, bool *pfmemalloc)
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{
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void *obj;
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bool ret_pfmemalloc = false;
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/*
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* Try a regular allocation, when that fails and we're not entitled
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* to the reserves, fail.
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*/
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obj = kmalloc_node_track_caller(size,
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flags | __GFP_NOMEMALLOC | __GFP_NOWARN,
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node);
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if (obj || !(gfp_pfmemalloc_allowed(flags)))
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goto out;
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/* Try again but now we are using pfmemalloc reserves */
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ret_pfmemalloc = true;
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obj = kmalloc_node_track_caller(size, flags, node);
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out:
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if (pfmemalloc)
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*pfmemalloc = ret_pfmemalloc;
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return obj;
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}
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/* Allocate a new skbuff. We do this ourselves so we can fill in a few
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* 'private' fields and also do memory statistics to find all the
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* [BEEP] leaks.
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*
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*/
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/**
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* __alloc_skb - allocate a network buffer
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* @size: size to allocate
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* @gfp_mask: allocation mask
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* @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache
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* instead of head cache and allocate a cloned (child) skb.
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* If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for
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* allocations in case the data is required for writeback
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* @node: numa node to allocate memory on
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*
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* Allocate a new &sk_buff. The returned buffer has no headroom and a
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* tail room of at least size bytes. The object has a reference count
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* of one. The return is the buffer. On a failure the return is %NULL.
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*
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* Buffers may only be allocated from interrupts using a @gfp_mask of
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* %GFP_ATOMIC.
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*/
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struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
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int flags, int node)
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{
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struct kmem_cache *cache;
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struct skb_shared_info *shinfo;
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struct sk_buff *skb;
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u8 *data;
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bool pfmemalloc;
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cache = (flags & SKB_ALLOC_FCLONE)
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? skbuff_fclone_cache : skbuff_head_cache;
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if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX))
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gfp_mask |= __GFP_MEMALLOC;
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/* Get the HEAD */
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skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node);
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if (!skb)
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goto out;
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prefetchw(skb);
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/* We do our best to align skb_shared_info on a separate cache
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* line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives
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* aligned memory blocks, unless SLUB/SLAB debug is enabled.
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* Both skb->head and skb_shared_info are cache line aligned.
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*/
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size = SKB_DATA_ALIGN(size);
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size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
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data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc);
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if (!data)
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goto nodata;
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/* kmalloc(size) might give us more room than requested.
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* Put skb_shared_info exactly at the end of allocated zone,
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* to allow max possible filling before reallocation.
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*/
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size = SKB_WITH_OVERHEAD(ksize(data));
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prefetchw(data + size);
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/*
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* Only clear those fields we need to clear, not those that we will
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* actually initialise below. Hence, don't put any more fields after
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* the tail pointer in struct sk_buff!
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*/
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memset(skb, 0, offsetof(struct sk_buff, tail));
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/* Account for allocated memory : skb + skb->head */
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skb->truesize = SKB_TRUESIZE(size);
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skb->pfmemalloc = pfmemalloc;
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refcount_set(&skb->users, 1);
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skb->head = data;
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skb->data = data;
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skb_reset_tail_pointer(skb);
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skb->end = skb->tail + size;
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skb->mac_header = (typeof(skb->mac_header))~0U;
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skb->transport_header = (typeof(skb->transport_header))~0U;
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/* make sure we initialize shinfo sequentially */
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shinfo = skb_shinfo(skb);
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memset(shinfo, 0, offsetof(struct skb_shared_info, dataref));
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atomic_set(&shinfo->dataref, 1);
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if (flags & SKB_ALLOC_FCLONE) {
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struct sk_buff_fclones *fclones;
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fclones = container_of(skb, struct sk_buff_fclones, skb1);
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skb->fclone = SKB_FCLONE_ORIG;
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refcount_set(&fclones->fclone_ref, 1);
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fclones->skb2.fclone = SKB_FCLONE_CLONE;
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}
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skb_set_kcov_handle(skb, kcov_common_handle());
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out:
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return skb;
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nodata:
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kmem_cache_free(cache, skb);
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skb = NULL;
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goto out;
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}
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EXPORT_SYMBOL(__alloc_skb);
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/**
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* __netdev_alloc_skb - allocate an skbuff for rx on a specific device
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* @dev: network device to receive on
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