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fd30d1cdcc
We increase cache->nr_cached when we free into the cache but don't
decrease when we take from it, so in some time we'll get an empty
cache with cache->nr_cached larger than IO_ALLOC_CACHE_MAX, that fails
io_alloc_cache_put() and effectively disables caching.
Fixes: 9b797a37c4 ("io_uring: add abstraction around apoll cache")
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
#ifndef IOU_ALLOC_CACHE_H
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#define IOU_ALLOC_CACHE_H
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/*
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* Don't allow the cache to grow beyond this size.
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*/
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#define IO_ALLOC_CACHE_MAX 512
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struct io_cache_entry {
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struct hlist_node node;
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};
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static inline bool io_alloc_cache_put(struct io_alloc_cache *cache,
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struct io_cache_entry *entry)
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{
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if (cache->nr_cached < IO_ALLOC_CACHE_MAX) {
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cache->nr_cached++;
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hlist_add_head(&entry->node, &cache->list);
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return true;
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}
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return false;
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}
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static inline struct io_cache_entry *io_alloc_cache_get(struct io_alloc_cache *cache)
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{
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if (!hlist_empty(&cache->list)) {
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struct hlist_node *node = cache->list.first;
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hlist_del(node);
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cache->nr_cached--;
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return container_of(node, struct io_cache_entry, node);
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}
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return NULL;
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}
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static inline void io_alloc_cache_init(struct io_alloc_cache *cache)
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{
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INIT_HLIST_HEAD(&cache->list);
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cache->nr_cached = 0;
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}
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static inline void io_alloc_cache_free(struct io_alloc_cache *cache,
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void (*free)(struct io_cache_entry *))
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{
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while (!hlist_empty(&cache->list)) {
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struct hlist_node *node = cache->list.first;
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hlist_del(node);
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free(container_of(node, struct io_cache_entry, node));
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}
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cache->nr_cached = 0;
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}
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#endif
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