diff options
author | Alexander Lobakin <alobakin@pm.me> | 2021-02-13 14:11:00 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2021-02-13 14:32:03 -0800 |
commit | 5381b23d5bf9c06899324a6268a78e1113ea5382 (patch) | |
tree | 68dbfe6668d75bcaff2a0c2cd96fc006e77356dc /net | |
parent | 773dc50d71690202afd7b5017c060c6ca8c75dd9 (diff) | |
download | linux-5381b23d5bf9c06899324a6268a78e1113ea5382.tar.bz2 |
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>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/skbuff.c | 284 |
1 files changed, 142 insertions, 142 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d380c7b5a12d..a0f846872d19 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -119,148 +119,6 @@ static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr) skb_panic(skb, sz, addr, __func__); } -/* - * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells - * the caller if emergency pfmemalloc reserves are being used. If it is and - * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves - * may be used. Otherwise, the packet data may be discarded until enough - * memory is free - */ -#define kmalloc_reserve(size, gfp, node, pfmemalloc) \ - __kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc) - -static void *__kmalloc_reserve(size_t size, gfp_t flags, int node, - unsigned long ip, bool *pfmemalloc) -{ - void *obj; - bool ret_pfmemalloc = false; - - /* - * Try a regular allocation, when that fails and we're not entitled - * to the reserves, fail. - */ - obj = kmalloc_node_track_caller(size, - flags | __GFP_NOMEMALLOC | __GFP_NOWARN, - node); - if (obj || !(gfp_pfmemalloc_allowed(flags))) - goto out; - - /* Try again but now we are using pfmemalloc reserves */ - ret_pfmemalloc = true; - obj = kmalloc_node_track_caller(size, flags, node); - -out: - if (pfmemalloc) - *pfmemalloc = ret_pfmemalloc; - - return obj; -} - -/* Allocate a new skbuff. We do this ourselves so we can fill in a few - * 'private' fields and also do memory statistics to find all the - * [BEEP] leaks. - * - */ - -/** - * __alloc_skb - allocate a network buffer - * @size: size to allocate - * @gfp_mask: allocation mask - * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache - * instead of head cache and allocate a cloned (child) skb. - * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for - * allocations in case the data is required for writeback - * @node: numa node to allocate memory on - * - * Allocate a new &sk_buff. The returned buffer has no headroom and a - * tail room of at least size bytes. The object has a reference count - * of one. The return is the buffer. On a failure the return is %NULL. - * - * Buffers may only be allocated from interrupts using a @gfp_mask of - * %GFP_ATOMIC. - */ -struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, - int flags, int node) -{ - struct kmem_cache *cache; - struct skb_shared_info *shinfo; - struct sk_buff *skb; - u8 *data; - bool pfmemalloc; - - cache = (flags & SKB_ALLOC_FCLONE) - ? skbuff_fclone_cache : skbuff_head_cache; - - if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) - gfp_mask |= __GFP_MEMALLOC; - - /* Get the HEAD */ - skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node); - if (!skb) - goto out; - prefetchw(skb); - - /* We do our best to align skb_shared_info on a separate cache - * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives - * aligned memory blocks, unless SLUB/SLAB debug is enabled. - * Both skb->head and skb_shared_info are cache line aligned. - */ - size = SKB_DATA_ALIGN(size); - size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); - if (!data) - goto nodata; - /* kmalloc(size) might give us more room than requested. - * Put skb_shared_info exactly at the end of allocated zone, - * to allow max possible filling before reallocation. - */ - size = SKB_WITH_OVERHEAD(ksize(data)); - prefetchw(data + size); - - /* - * Only clear those fields we need to clear, not those that we will - * actually initialise below. Hence, don't put any more fields after - * the tail pointer in struct sk_buff! - */ - memset(skb, 0, offsetof(struct sk_buff, tail)); - /* Account for allocated memory : skb + skb->head */ - skb->truesize = SKB_TRUESIZE(size); - skb->pfmemalloc = pfmemalloc; - refcount_set(&skb->users, 1); - skb->head = data; - skb->data = data; - skb_reset_tail_pointer(skb); - skb->end = skb->tail + size; - skb->mac_header = (typeof(skb->mac_header))~0U; - skb->transport_header = (typeof(skb->transport_header))~0U; - - /* make sure we initialize shinfo sequentially */ - shinfo = skb_shinfo(skb); - memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); - atomic_set(&shinfo->dataref, 1); - - if (flags & SKB_ALLOC_FCLONE) { - struct sk_buff_fclones *fclones; - - fclones = container_of(skb, struct sk_buff_fclones, skb1); - - skb->fclone = SKB_FCLONE_ORIG; - refcount_set(&fclones->fclone_ref, 1); - - fclones->skb2.fclone = SKB_FCLONE_CLONE; - } - - skb_set_kcov_handle(skb, kcov_common_handle()); - -out: - return skb; -nodata: - kmem_cache_free(cache, skb); - skb = NULL; - goto out; -} -EXPORT_SYMBOL(__alloc_skb); - /* Caller must provide SKB that is memset cleared */ static struct sk_buff *__build_skb_around(struct sk_buff *skb, void *data, unsigned int frag_size) @@ -408,6 +266,148 @@ void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) } EXPORT_SYMBOL(__netdev_alloc_frag_align); +/* + * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells + * the caller if emergency pfmemalloc reserves are being used. If it is and + * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves + * may be used. Otherwise, the packet data may be discarded until enough + * memory is free + */ +#define kmalloc_reserve(size, gfp, node, pfmemalloc) \ + __kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc) + +static void *__kmalloc_reserve(size_t size, gfp_t flags, int node, + unsigned long ip, bool *pfmemalloc) +{ + void *obj; + bool ret_pfmemalloc = false; + + /* + * Try a regular allocation, when that fails and we're not entitled + * to the reserves, fail. + */ + obj = kmalloc_node_track_caller(size, + flags | __GFP_NOMEMALLOC | __GFP_NOWARN, + node); + if (obj || !(gfp_pfmemalloc_allowed(flags))) + goto out; + + /* Try again but now we are using pfmemalloc reserves */ + ret_pfmemalloc = true; + obj = kmalloc_node_track_caller(size, flags, node); + +out: + if (pfmemalloc) + *pfmemalloc = ret_pfmemalloc; + + return obj; +} + +/* Allocate a new skbuff. We do this ourselves so we can fill in a few + * 'private' fields and also do memory statistics to find all the + * [BEEP] leaks. + * + */ + +/** + * __alloc_skb - allocate a network buffer + * @size: size to allocate + * @gfp_mask: allocation mask + * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache + * instead of head cache and allocate a cloned (child) skb. + * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for + * allocations in case the data is required for writeback + * @node: numa node to allocate memory on + * + * Allocate a new &sk_buff. The returned buffer has no headroom and a + * tail room of at least size bytes. The object has a reference count + * of one. The return is the buffer. On a failure the return is %NULL. + * + * Buffers may only be allocated from interrupts using a @gfp_mask of + * %GFP_ATOMIC. + */ +struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, + int flags, int node) +{ + struct kmem_cache *cache; + struct skb_shared_info *shinfo; + struct sk_buff *skb; + u8 *data; + bool pfmemalloc; + + cache = (flags & SKB_ALLOC_FCLONE) + ? skbuff_fclone_cache : skbuff_head_cache; + + if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) + gfp_mask |= __GFP_MEMALLOC; + + /* Get the HEAD */ + skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node); + if (!skb) + goto out; + prefetchw(skb); + + /* We do our best to align skb_shared_info on a separate cache + * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives + * aligned memory blocks, unless SLUB/SLAB debug is enabled. + * Both skb->head and skb_shared_info are cache line aligned. + */ + size = SKB_DATA_ALIGN(size); + size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); + if (!data) + goto nodata; + /* kmalloc(size) might give us more room than requested. + * Put skb_shared_info exactly at the end of allocated zone, + * to allow max possible filling before reallocation. + */ + size = SKB_WITH_OVERHEAD(ksize(data)); + prefetchw(data + size); + + /* + * Only clear those fields we need to clear, not those that we will + * actually initialise below. Hence, don't put any more fields after + * the tail pointer in struct sk_buff! + */ + memset(skb, 0, offsetof(struct sk_buff, tail)); + /* Account for allocated memory : skb + skb->head */ + skb->truesize = SKB_TRUESIZE(size); + skb->pfmemalloc = pfmemalloc; + refcount_set(&skb->users, 1); + skb->head = data; + skb->data = data; + skb_reset_tail_pointer(skb); + skb->end = skb->tail + size; + skb->mac_header = (typeof(skb->mac_header))~0U; + skb->transport_header = (typeof(skb->transport_header))~0U; + + /* make sure we initialize shinfo sequentially */ + shinfo = skb_shinfo(skb); + memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); + atomic_set(&shinfo->dataref, 1); + + if (flags & SKB_ALLOC_FCLONE) { + struct sk_buff_fclones *fclones; + + fclones = container_of(skb, struct sk_buff_fclones, skb1); + + skb->fclone = SKB_FCLONE_ORIG; + refcount_set(&fclones->fclone_ref, 1); + + fclones->skb2.fclone = SKB_FCLONE_CLONE; + } + + skb_set_kcov_handle(skb, kcov_common_handle()); + +out: + return skb; +nodata: + kmem_cache_free(cache, skb); + skb = NULL; + goto out; +} +EXPORT_SYMBOL(__alloc_skb); + /** * __netdev_alloc_skb - allocate an skbuff for rx on a specific device * @dev: network device to receive on |