fs/mbcache.c: change block and index hash chain to hlist_bl_node
This patch changes each mb_cache's both block and index hash chains to use a hlist_bl_node, which contains a built-in lock. This is the first step in decoupling of locks serializing accesses to mb_cache global data and each mb_cache_entry local data. Signed-off-by: T. Makphaibulchoke <tmac@hp.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
parent
b8a8684502
commit
3e037e5211
117
fs/mbcache.c
117
fs/mbcache.c
@ -34,9 +34,9 @@
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#include <linux/mm.h>
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#include <linux/mm.h>
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#include <linux/slab.h>
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/list_bl.h>
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#include <linux/mbcache.h>
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#include <linux/mbcache.h>
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#include <linux/init.h>
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#ifdef MB_CACHE_DEBUG
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#ifdef MB_CACHE_DEBUG
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# define mb_debug(f...) do { \
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# define mb_debug(f...) do { \
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@ -87,22 +87,39 @@ static LIST_HEAD(mb_cache_lru_list);
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static DEFINE_SPINLOCK(mb_cache_spinlock);
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static DEFINE_SPINLOCK(mb_cache_spinlock);
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static inline int
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static inline int
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__mb_cache_entry_is_hashed(struct mb_cache_entry *ce)
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__mb_cache_entry_is_block_hashed(struct mb_cache_entry *ce)
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{
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{
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return !list_empty(&ce->e_block_list);
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return !hlist_bl_unhashed(&ce->e_block_list);
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}
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}
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static void
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static inline void
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__mb_cache_entry_unhash_block(struct mb_cache_entry *ce)
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{
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if (__mb_cache_entry_is_block_hashed(ce))
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hlist_bl_del_init(&ce->e_block_list);
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}
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static inline int
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__mb_cache_entry_is_index_hashed(struct mb_cache_entry *ce)
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{
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return !hlist_bl_unhashed(&ce->e_index.o_list);
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}
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static inline void
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__mb_cache_entry_unhash_index(struct mb_cache_entry *ce)
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{
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if (__mb_cache_entry_is_index_hashed(ce))
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hlist_bl_del_init(&ce->e_index.o_list);
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}
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static inline void
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__mb_cache_entry_unhash(struct mb_cache_entry *ce)
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__mb_cache_entry_unhash(struct mb_cache_entry *ce)
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{
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{
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if (__mb_cache_entry_is_hashed(ce)) {
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__mb_cache_entry_unhash_index(ce);
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list_del_init(&ce->e_block_list);
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__mb_cache_entry_unhash_block(ce);
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list_del(&ce->e_index.o_list);
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}
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}
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}
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static void
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static void
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__mb_cache_entry_forget(struct mb_cache_entry *ce, gfp_t gfp_mask)
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__mb_cache_entry_forget(struct mb_cache_entry *ce, gfp_t gfp_mask)
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{
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{
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@ -125,7 +142,7 @@ __mb_cache_entry_release_unlock(struct mb_cache_entry *ce)
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ce->e_used -= MB_CACHE_WRITER;
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ce->e_used -= MB_CACHE_WRITER;
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ce->e_used--;
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ce->e_used--;
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if (!(ce->e_used || ce->e_queued)) {
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if (!(ce->e_used || ce->e_queued)) {
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if (!__mb_cache_entry_is_hashed(ce))
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if (!__mb_cache_entry_is_block_hashed(ce))
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goto forget;
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goto forget;
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mb_assert(list_empty(&ce->e_lru_list));
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mb_assert(list_empty(&ce->e_lru_list));
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list_add_tail(&ce->e_lru_list, &mb_cache_lru_list);
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list_add_tail(&ce->e_lru_list, &mb_cache_lru_list);
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@ -221,18 +238,18 @@ mb_cache_create(const char *name, int bucket_bits)
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cache->c_name = name;
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cache->c_name = name;
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atomic_set(&cache->c_entry_count, 0);
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atomic_set(&cache->c_entry_count, 0);
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cache->c_bucket_bits = bucket_bits;
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cache->c_bucket_bits = bucket_bits;
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cache->c_block_hash = kmalloc(bucket_count * sizeof(struct list_head),
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cache->c_block_hash = kmalloc(bucket_count *
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GFP_KERNEL);
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sizeof(struct hlist_bl_head), GFP_KERNEL);
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if (!cache->c_block_hash)
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if (!cache->c_block_hash)
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goto fail;
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goto fail;
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for (n=0; n<bucket_count; n++)
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for (n=0; n<bucket_count; n++)
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INIT_LIST_HEAD(&cache->c_block_hash[n]);
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INIT_HLIST_BL_HEAD(&cache->c_block_hash[n]);
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cache->c_index_hash = kmalloc(bucket_count * sizeof(struct list_head),
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cache->c_index_hash = kmalloc(bucket_count *
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GFP_KERNEL);
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sizeof(struct hlist_bl_head), GFP_KERNEL);
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if (!cache->c_index_hash)
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if (!cache->c_index_hash)
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goto fail;
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goto fail;
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for (n=0; n<bucket_count; n++)
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for (n=0; n<bucket_count; n++)
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INIT_LIST_HEAD(&cache->c_index_hash[n]);
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INIT_HLIST_BL_HEAD(&cache->c_index_hash[n]);
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cache->c_entry_cache = kmem_cache_create(name,
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cache->c_entry_cache = kmem_cache_create(name,
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sizeof(struct mb_cache_entry), 0,
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sizeof(struct mb_cache_entry), 0,
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SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
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SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
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@ -364,10 +381,13 @@ mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags)
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return NULL;
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return NULL;
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atomic_inc(&cache->c_entry_count);
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atomic_inc(&cache->c_entry_count);
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INIT_LIST_HEAD(&ce->e_lru_list);
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INIT_LIST_HEAD(&ce->e_lru_list);
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INIT_LIST_HEAD(&ce->e_block_list);
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INIT_HLIST_BL_NODE(&ce->e_block_list);
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INIT_HLIST_BL_NODE(&ce->e_index.o_list);
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ce->e_cache = cache;
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ce->e_cache = cache;
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ce->e_queued = 0;
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ce->e_queued = 0;
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}
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}
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ce->e_block_hash_p = &cache->c_block_hash[0];
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ce->e_index_hash_p = &cache->c_index_hash[0];
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ce->e_used = 1 + MB_CACHE_WRITER;
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ce->e_used = 1 + MB_CACHE_WRITER;
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return ce;
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return ce;
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}
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}
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@ -393,25 +413,32 @@ mb_cache_entry_insert(struct mb_cache_entry *ce, struct block_device *bdev,
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{
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{
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struct mb_cache *cache = ce->e_cache;
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struct mb_cache *cache = ce->e_cache;
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unsigned int bucket;
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unsigned int bucket;
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struct list_head *l;
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struct hlist_bl_node *l;
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int error = -EBUSY;
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int error = -EBUSY;
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struct hlist_bl_head *block_hash_p;
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struct hlist_bl_head *index_hash_p;
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struct mb_cache_entry *lce;
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mb_assert(ce);
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bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
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bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
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cache->c_bucket_bits);
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cache->c_bucket_bits);
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block_hash_p = &cache->c_block_hash[bucket];
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spin_lock(&mb_cache_spinlock);
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spin_lock(&mb_cache_spinlock);
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list_for_each_prev(l, &cache->c_block_hash[bucket]) {
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hlist_bl_for_each_entry(lce, l, block_hash_p, e_block_list) {
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struct mb_cache_entry *ce =
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if (lce->e_bdev == bdev && lce->e_block == block)
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list_entry(l, struct mb_cache_entry, e_block_list);
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if (ce->e_bdev == bdev && ce->e_block == block)
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goto out;
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goto out;
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}
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}
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mb_assert(!__mb_cache_entry_is_block_hashed(ce));
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__mb_cache_entry_unhash(ce);
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__mb_cache_entry_unhash(ce);
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ce->e_bdev = bdev;
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ce->e_bdev = bdev;
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ce->e_block = block;
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ce->e_block = block;
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list_add(&ce->e_block_list, &cache->c_block_hash[bucket]);
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ce->e_block_hash_p = block_hash_p;
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ce->e_index.o_key = key;
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ce->e_index.o_key = key;
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bucket = hash_long(key, cache->c_bucket_bits);
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bucket = hash_long(key, cache->c_bucket_bits);
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list_add(&ce->e_index.o_list, &cache->c_index_hash[bucket]);
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index_hash_p = &cache->c_index_hash[bucket];
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ce->e_index_hash_p = index_hash_p;
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hlist_bl_add_head(&ce->e_index.o_list, index_hash_p);
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hlist_bl_add_head(&ce->e_block_list, block_hash_p);
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error = 0;
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error = 0;
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out:
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out:
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spin_unlock(&mb_cache_spinlock);
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spin_unlock(&mb_cache_spinlock);
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@ -463,14 +490,16 @@ mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev,
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sector_t block)
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sector_t block)
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{
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{
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unsigned int bucket;
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unsigned int bucket;
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struct list_head *l;
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struct hlist_bl_node *l;
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struct mb_cache_entry *ce;
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struct mb_cache_entry *ce;
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struct hlist_bl_head *block_hash_p;
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bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
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bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
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cache->c_bucket_bits);
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cache->c_bucket_bits);
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block_hash_p = &cache->c_block_hash[bucket];
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spin_lock(&mb_cache_spinlock);
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spin_lock(&mb_cache_spinlock);
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list_for_each(l, &cache->c_block_hash[bucket]) {
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hlist_bl_for_each_entry(ce, l, block_hash_p, e_block_list) {
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ce = list_entry(l, struct mb_cache_entry, e_block_list);
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mb_assert(ce->e_block_hash_p == block_hash_p);
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if (ce->e_bdev == bdev && ce->e_block == block) {
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if (ce->e_bdev == bdev && ce->e_block == block) {
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DEFINE_WAIT(wait);
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DEFINE_WAIT(wait);
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@ -489,7 +518,7 @@ mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev,
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finish_wait(&mb_cache_queue, &wait);
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finish_wait(&mb_cache_queue, &wait);
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ce->e_used += 1 + MB_CACHE_WRITER;
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ce->e_used += 1 + MB_CACHE_WRITER;
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if (!__mb_cache_entry_is_hashed(ce)) {
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if (!__mb_cache_entry_is_block_hashed(ce)) {
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__mb_cache_entry_release_unlock(ce);
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__mb_cache_entry_release_unlock(ce);
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return NULL;
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return NULL;
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}
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}
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@ -506,12 +535,14 @@ cleanup:
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#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0)
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#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0)
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static struct mb_cache_entry *
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static struct mb_cache_entry *
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__mb_cache_entry_find(struct list_head *l, struct list_head *head,
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__mb_cache_entry_find(struct hlist_bl_node *l, struct hlist_bl_head *head,
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struct block_device *bdev, unsigned int key)
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struct block_device *bdev, unsigned int key)
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{
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{
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while (l != head) {
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while (l != NULL) {
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struct mb_cache_entry *ce =
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struct mb_cache_entry *ce =
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list_entry(l, struct mb_cache_entry, e_index.o_list);
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hlist_bl_entry(l, struct mb_cache_entry,
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e_index.o_list);
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mb_assert(ce->e_index_hash_p == head);
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if (ce->e_bdev == bdev && ce->e_index.o_key == key) {
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if (ce->e_bdev == bdev && ce->e_index.o_key == key) {
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DEFINE_WAIT(wait);
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DEFINE_WAIT(wait);
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@ -532,7 +563,7 @@ __mb_cache_entry_find(struct list_head *l, struct list_head *head,
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}
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}
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finish_wait(&mb_cache_queue, &wait);
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finish_wait(&mb_cache_queue, &wait);
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if (!__mb_cache_entry_is_hashed(ce)) {
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if (!__mb_cache_entry_is_block_hashed(ce)) {
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__mb_cache_entry_release_unlock(ce);
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__mb_cache_entry_release_unlock(ce);
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spin_lock(&mb_cache_spinlock);
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spin_lock(&mb_cache_spinlock);
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return ERR_PTR(-EAGAIN);
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return ERR_PTR(-EAGAIN);
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@ -562,12 +593,16 @@ mb_cache_entry_find_first(struct mb_cache *cache, struct block_device *bdev,
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unsigned int key)
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unsigned int key)
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{
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{
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unsigned int bucket = hash_long(key, cache->c_bucket_bits);
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unsigned int bucket = hash_long(key, cache->c_bucket_bits);
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struct list_head *l;
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struct hlist_bl_node *l;
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struct mb_cache_entry *ce;
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struct mb_cache_entry *ce = NULL;
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struct hlist_bl_head *index_hash_p;
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index_hash_p = &cache->c_index_hash[bucket];
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spin_lock(&mb_cache_spinlock);
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spin_lock(&mb_cache_spinlock);
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l = cache->c_index_hash[bucket].next;
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if (!hlist_bl_empty(index_hash_p)) {
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ce = __mb_cache_entry_find(l, &cache->c_index_hash[bucket], bdev, key);
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l = hlist_bl_first(index_hash_p);
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ce = __mb_cache_entry_find(l, index_hash_p, bdev, key);
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}
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spin_unlock(&mb_cache_spinlock);
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spin_unlock(&mb_cache_spinlock);
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return ce;
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return ce;
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}
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}
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@ -597,12 +632,16 @@ mb_cache_entry_find_next(struct mb_cache_entry *prev,
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{
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{
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struct mb_cache *cache = prev->e_cache;
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struct mb_cache *cache = prev->e_cache;
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unsigned int bucket = hash_long(key, cache->c_bucket_bits);
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unsigned int bucket = hash_long(key, cache->c_bucket_bits);
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struct list_head *l;
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struct hlist_bl_node *l;
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struct mb_cache_entry *ce;
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struct mb_cache_entry *ce;
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struct hlist_bl_head *index_hash_p;
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index_hash_p = &cache->c_index_hash[bucket];
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mb_assert(prev->e_index_hash_p == index_hash_p);
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spin_lock(&mb_cache_spinlock);
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spin_lock(&mb_cache_spinlock);
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mb_assert(!hlist_bl_empty(index_hash_p));
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l = prev->e_index.o_list.next;
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l = prev->e_index.o_list.next;
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ce = __mb_cache_entry_find(l, &cache->c_index_hash[bucket], bdev, key);
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ce = __mb_cache_entry_find(l, index_hash_p, bdev, key);
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__mb_cache_entry_release_unlock(prev);
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__mb_cache_entry_release_unlock(prev);
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return ce;
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return ce;
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}
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}
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@ -3,19 +3,21 @@
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(C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
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(C) 2001 by Andreas Gruenbacher, <a.gruenbacher@computer.org>
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*/
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*/
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struct mb_cache_entry {
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struct mb_cache_entry {
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struct list_head e_lru_list;
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struct list_head e_lru_list;
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struct mb_cache *e_cache;
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struct mb_cache *e_cache;
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unsigned short e_used;
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unsigned short e_used;
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unsigned short e_queued;
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unsigned short e_queued;
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atomic_t e_refcnt;
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struct block_device *e_bdev;
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struct block_device *e_bdev;
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sector_t e_block;
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sector_t e_block;
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struct list_head e_block_list;
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struct hlist_bl_node e_block_list;
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struct {
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struct {
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struct list_head o_list;
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struct hlist_bl_node o_list;
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unsigned int o_key;
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unsigned int o_key;
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} e_index;
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} e_index;
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struct hlist_bl_head *e_block_hash_p;
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struct hlist_bl_head *e_index_hash_p;
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};
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};
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struct mb_cache {
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struct mb_cache {
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@ -25,8 +27,8 @@ struct mb_cache {
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int c_max_entries;
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int c_max_entries;
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int c_bucket_bits;
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int c_bucket_bits;
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struct kmem_cache *c_entry_cache;
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struct kmem_cache *c_entry_cache;
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struct list_head *c_block_hash;
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struct hlist_bl_head *c_block_hash;
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struct list_head *c_index_hash;
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struct hlist_bl_head *c_index_hash;
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};
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};
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/* Functions on caches */
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/* Functions on caches */
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