Commit 129e5824 authored by Kinglong Mee's avatar Kinglong Mee Committed by J. Bruce Fields
Browse files

sunrpc: Switch to using hash list instead single list 



Switch using list_head for cache_head in cache_detail,
it is useful of remove an cache_head entry directly from cache_detail.

v8, using hash list, not head list

Signed-off-by: default avatarKinglong Mee <kinglongmee@gmail.com>
Reviewed-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent c8c081b7

include/linux/sunrpc/cache.h

+2 −2
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ 
 * 

 */

struct cache_head {

	struct cache_head * next;

	struct hlist_node	cache_list;

	time_t		expiry_time;	/* After time time, don't use the data */

	time_t		last_refresh;   /* If CACHE_PENDING, this is when upcall 

					 * was sent, else this is when update was received
@@ -73,7 +73,7 @@ struct cache_detail_pipefs { 
struct cache_detail {

	struct module *		owner;

	int			hash_size;

	struct cache_head **	hash_table;

	struct hlist_head *	hash_table;

	rwlock_t		hash_lock;



	atomic_t		inuse; /* active user-space update or lookup */

net/sunrpc/cache.c

+31 −29
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ static void cache_revisit_request(struct cache_head *item); 
static void cache_init(struct cache_head *h)

{

	time_t now = seconds_since_boot();

	h->next = NULL;

	INIT_HLIST_NODE(&h->cache_list);

	h->flags = 0;

	kref_init(&h->ref);

	h->expiry_time = now + CACHE_NEW_EXPIRY;
@@ -54,15 +54,14 @@ static void cache_init(struct cache_head *h) 
struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,

				       struct cache_head *key, int hash)

{

	struct cache_head **head,  **hp;

	struct cache_head *new = NULL, *freeme = NULL;

	struct cache_head *new = NULL, *freeme = NULL, *tmp = NULL;

	struct hlist_head *head;



	head = &detail->hash_table[hash];



	read_lock(&detail->hash_lock);



	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {

		struct cache_head *tmp = *hp;

	hlist_for_each_entry(tmp, head, cache_list) {

		if (detail->match(tmp, key)) {

			if (cache_is_expired(detail, tmp))

				/* This entry is expired, we will discard it. */
@@ -88,12 +87,10 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, 
	write_lock(&detail->hash_lock);



	/* check if entry appeared while we slept */

	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {

		struct cache_head *tmp = *hp;

	hlist_for_each_entry(tmp, head, cache_list) {

		if (detail->match(tmp, key)) {

			if (cache_is_expired(detail, tmp)) {

				*hp = tmp->next;

				tmp->next = NULL;

				hlist_del_init(&tmp->cache_list);

				detail->entries --;

				freeme = tmp;

				break;
@@ -104,8 +101,8 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, 
			return tmp;

		}

	}

	new->next = *head;

	*head = new;



	hlist_add_head(&new->cache_list, head);

	detail->entries++;

	cache_get(new);

	write_unlock(&detail->hash_lock);
@@ -143,7 +140,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
	 * If 'old' is not VALID, we update it directly,

	 * otherwise we need to replace it

	 */

	struct cache_head **head;

	struct cache_head *tmp;



	if (!test_bit(CACHE_VALID, &old->flags)) {
@@ -168,15 +164,13 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, 
	}

	cache_init(tmp);

	detail->init(tmp, old);

	head = &detail->hash_table[hash];



	write_lock(&detail->hash_lock);

	if (test_bit(CACHE_NEGATIVE, &new->flags))

		set_bit(CACHE_NEGATIVE, &tmp->flags);

	else

		detail->update(tmp, new);

	tmp->next = *head;

	*head = tmp;

	hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]);

	detail->entries++;

	cache_get(tmp);

	cache_fresh_locked(tmp, new->expiry_time);
@@ -416,28 +410,29 @@ static int cache_clean(void) 
	/* find a non-empty bucket in the table */

	while (current_detail &&

	       current_index < current_detail->hash_size &&

	       current_detail->hash_table[current_index] == NULL)

	       hlist_empty(&current_detail->hash_table[current_index]))

		current_index++;



	/* find a cleanable entry in the bucket and clean it, or set to next bucket */



	if (current_detail && current_index < current_detail->hash_size) {

		struct cache_head *ch, **cp;

		struct cache_head *ch = NULL;

		struct cache_detail *d;

		struct hlist_head *head;

		struct hlist_node *tmp;



		write_lock(&current_detail->hash_lock);



		/* Ok, now to clean this strand */



		cp = & current_detail->hash_table[current_index];

		for (ch = *cp ; ch ; cp = & ch->next, ch = *cp) {

		head = &current_detail->hash_table[current_index];

		hlist_for_each_entry_safe(ch, tmp, head, cache_list) {

			if (current_detail->nextcheck > ch->expiry_time)

				current_detail->nextcheck = ch->expiry_time+1;

			if (!cache_is_expired(current_detail, ch))

				continue;



			*cp = ch->next;

			ch->next = NULL;

			hlist_del_init(&ch->cache_list);

			current_detail->entries--;

			rv = 1;

			break;
@@ -1284,7 +1279,7 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) 
	hash = n >> 32;

	entry = n & ((1LL<<32) - 1);



	for (ch=cd->hash_table[hash]; ch; ch=ch->next)

	hlist_for_each_entry(ch, &cd->hash_table[hash], cache_list)

		if (!entry--)

			return ch;

	n &= ~((1LL<<32) - 1);
@@ -1292,11 +1287,12 @@ void *cache_seq_start(struct seq_file *m, loff_t *pos) 
		hash++;

		n += 1LL<<32;

	} while(hash < cd->hash_size &&

		cd->hash_table[hash]==NULL);

		hlist_empty(&cd->hash_table[hash]));

	if (hash >= cd->hash_size)

		return NULL;

	*pos = n+1;

	return cd->hash_table[hash];

	return hlist_entry_safe(cd->hash_table[hash].first,

				struct cache_head, cache_list);

}

EXPORT_SYMBOL_GPL(cache_seq_start);
@@ -1308,23 +1304,25 @@ void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos) 


	if (p == SEQ_START_TOKEN)

		hash = 0;

	else if (ch->next == NULL) {

	else if (ch->cache_list.next == NULL) {

		hash++;

		*pos += 1LL<<32;

	} else {

		++*pos;

		return ch->next;

		return hlist_entry_safe(ch->cache_list.next,

					struct cache_head, cache_list);

	}

	*pos &= ~((1LL<<32) - 1);

	while (hash < cd->hash_size &&

	       cd->hash_table[hash] == NULL) {

	       hlist_empty(&cd->hash_table[hash])) {

		hash++;

		*pos += 1LL<<32;

	}

	if (hash >= cd->hash_size)

		return NULL;

	++*pos;

	return cd->hash_table[hash];

	return hlist_entry_safe(cd->hash_table[hash].first,

				struct cache_head, cache_list);

}

EXPORT_SYMBOL_GPL(cache_seq_next);
@@ -1666,17 +1664,21 @@ EXPORT_SYMBOL_GPL(cache_unregister_net); 
struct cache_detail *cache_create_net(struct cache_detail *tmpl, struct net *net)

{

	struct cache_detail *cd;

	int i;



	cd = kmemdup(tmpl, sizeof(struct cache_detail), GFP_KERNEL);

	if (cd == NULL)

		return ERR_PTR(-ENOMEM);



	cd->hash_table = kzalloc(cd->hash_size * sizeof(struct cache_head *),

	cd->hash_table = kzalloc(cd->hash_size * sizeof(struct hlist_head),

				 GFP_KERNEL);

	if (cd->hash_table == NULL) {

		kfree(cd);

		return ERR_PTR(-ENOMEM);

	}



	for (i = 0; i < cd->hash_size; i++)

		INIT_HLIST_HEAD(&cd->hash_table[i]);

	cd->net = net;

	return cd;

}

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