X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=net%2Fsunrpc%2Fcache.c;h=14274490f92e8d9b521b5396320c5e76178adb5e;hb=refs%2Fheads%2Fvserver;hp=e84acd07f82286f79d107e229bed6cd877eb594a;hpb=9213980e6a70d8473e0ffd4b39ab5b6caaba9ff5;p=linux-2.6.git

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index e84acd07f..14274490f 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -26,6 +26,7 @@
 #include <linux/proc_fs.h>
 #include <linux/net.h>
 #include <linux/workqueue.h>
+#include <linux/mutex.h>
 #include <asm/ioctls.h>
 #include <linux/sunrpc/types.h>
 #include <linux/sunrpc/cache.h>
@@ -33,16 +34,146 @@
 
 #define	 RPCDBG_FACILITY RPCDBG_CACHE
 
-void cache_init(struct cache_head *h)
+static int cache_defer_req(struct cache_req *req, struct cache_head *item);
+static void cache_revisit_request(struct cache_head *item);
+
+static void cache_init(struct cache_head *h)
 {
 	time_t now = get_seconds();
 	h->next = NULL;
 	h->flags = 0;
-	atomic_set(&h->refcnt, 0);
+	kref_init(&h->ref);
 	h->expiry_time = now + CACHE_NEW_EXPIRY;
 	h->last_refresh = now;
 }
 
+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;
+
+	head = &detail->hash_table[hash];
+
+	read_lock(&detail->hash_lock);
+
+	for (hp=head; *hp != NULL ; hp = &(*hp)->next) {
+		struct cache_head *tmp = *hp;
+		if (detail->match(tmp, key)) {
+			cache_get(tmp);
+			read_unlock(&detail->hash_lock);
+			return tmp;
+		}
+	}
+	read_unlock(&detail->hash_lock);
+	/* Didn't find anything, insert an empty entry */
+
+	new = detail->alloc();
+	if (!new)
+		return NULL;
+	/* must fully initialise 'new', else
+	 * we might get lose if we need to
+	 * cache_put it soon.
+	 */
+	cache_init(new);
+	detail->init(new, key);
+
+	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;
+		if (detail->match(tmp, key)) {
+			cache_get(tmp);
+			write_unlock(&detail->hash_lock);
+			cache_put(new, detail);
+			return tmp;
+		}
+	}
+	new->next = *head;
+	*head = new;
+	detail->entries++;
+	cache_get(new);
+	write_unlock(&detail->hash_lock);
+
+	return new;
+}
+EXPORT_SYMBOL(sunrpc_cache_lookup);
+
+
+static void queue_loose(struct cache_detail *detail, struct cache_head *ch);
+
+static int cache_fresh_locked(struct cache_head *head, time_t expiry)
+{
+	head->expiry_time = expiry;
+	head->last_refresh = get_seconds();
+	return !test_and_set_bit(CACHE_VALID, &head->flags);
+}
+
+static void cache_fresh_unlocked(struct cache_head *head,
+			struct cache_detail *detail, int new)
+{
+	if (new)
+		cache_revisit_request(head);
+	if (test_and_clear_bit(CACHE_PENDING, &head->flags)) {
+		cache_revisit_request(head);
+		queue_loose(detail, head);
+	}
+}
+
+struct cache_head *sunrpc_cache_update(struct cache_detail *detail,
+				       struct cache_head *new, struct cache_head *old, int hash)
+{
+	/* The 'old' entry is to be replaced by 'new'.
+	 * If 'old' is not VALID, we update it directly,
+	 * otherwise we need to replace it
+	 */
+	struct cache_head **head;
+	struct cache_head *tmp;
+	int is_new;
+
+	if (!test_bit(CACHE_VALID, &old->flags)) {
+		write_lock(&detail->hash_lock);
+		if (!test_bit(CACHE_VALID, &old->flags)) {
+			if (test_bit(CACHE_NEGATIVE, &new->flags))
+				set_bit(CACHE_NEGATIVE, &old->flags);
+			else
+				detail->update(old, new);
+			is_new = cache_fresh_locked(old, new->expiry_time);
+			write_unlock(&detail->hash_lock);
+			cache_fresh_unlocked(old, detail, is_new);
+			return old;
+		}
+		write_unlock(&detail->hash_lock);
+	}
+	/* We need to insert a new entry */
+	tmp = detail->alloc();
+	if (!tmp) {
+		cache_put(old, detail);
+		return NULL;
+	}
+	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;
+	detail->entries++;
+	cache_get(tmp);
+	is_new = cache_fresh_locked(tmp, new->expiry_time);
+	cache_fresh_locked(old, 0);
+	write_unlock(&detail->hash_lock);
+	cache_fresh_unlocked(tmp, detail, is_new);
+	cache_fresh_unlocked(old, detail, 0);
+	cache_put(old, detail);
+	return tmp;
+}
+EXPORT_SYMBOL(sunrpc_cache_update);
 
 static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h);
 /*
@@ -54,6 +185,7 @@ static int cache_make_upcall(struct cache_detail *detail, struct cache_head *h);
  *
  * Returns 0 if the cache_head can be used, or cache_puts it and returns
  * -EAGAIN if upcall is pending,
+ * -ETIMEDOUT if upcall failed and should be retried,
  * -ENOENT if cache entry was negative
  */
 int cache_check(struct cache_detail *detail,
@@ -90,7 +222,8 @@ int cache_check(struct cache_detail *detail,
 				clear_bit(CACHE_PENDING, &h->flags);
 				if (rv == -EAGAIN) {
 					set_bit(CACHE_NEGATIVE, &h->flags);
-					cache_fresh(detail, h, get_seconds()+CACHE_NEW_EXPIRY);
+					cache_fresh_unlocked(h, detail,
+					     cache_fresh_locked(h, get_seconds()+CACHE_NEW_EXPIRY));
 					rv = -ENOENT;
 				}
 				break;
@@ -104,27 +237,14 @@ int cache_check(struct cache_detail *detail,
 	}
 
 	if (rv == -EAGAIN)
-		cache_defer_req(rqstp, h);
+		if (cache_defer_req(rqstp, h) != 0)
+			rv = -ETIMEDOUT;
 
-	if (rv && h)
-		detail->cache_put(h, detail);
+	if (rv)
+		cache_put(h, detail);
 	return rv;
 }
 
-static void queue_loose(struct cache_detail *detail, struct cache_head *ch);
-
-void cache_fresh(struct cache_detail *detail,
-		 struct cache_head *head, time_t expiry)
-{
-
-	head->expiry_time = expiry;
-	head->last_refresh = get_seconds();
-	if (!test_and_set_bit(CACHE_VALID, &head->flags))
-		cache_revisit_request(head);
-	if (test_and_clear_bit(CACHE_PENDING, &head->flags))
-		queue_loose(detail, head);
-}
-
 /*
  * caches need to be periodically cleaned.
  * For this we maintain a list of cache_detail and
@@ -158,7 +278,7 @@ void cache_fresh(struct cache_detail *detail,
  */
 
 static LIST_HEAD(cache_list);
-static spinlock_t cache_list_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(cache_list_lock);
 static struct cache_detail *current_detail;
 static int current_index;
 
@@ -166,15 +286,15 @@ static struct file_operations cache_file_operations;
 static struct file_operations content_file_operations;
 static struct file_operations cache_flush_operations;
 
-static void do_cache_clean(void *data);
-static DECLARE_WORK(cache_cleaner, do_cache_clean, NULL);
+static void do_cache_clean(struct work_struct *work);
+static DECLARE_DELAYED_WORK(cache_cleaner, do_cache_clean);
 
 void cache_register(struct cache_detail *cd)
 {
 	cd->proc_ent = proc_mkdir(cd->name, proc_net_rpc);
 	if (cd->proc_ent) {
 		struct proc_dir_entry *p;
-		cd->proc_ent->owner = THIS_MODULE;
+		cd->proc_ent->owner = cd->owner;
 		cd->channel_ent = cd->content_ent = NULL;
 		
  		p = create_proc_entry("flush", S_IFREG|S_IRUSR|S_IWUSR,
@@ -182,7 +302,7 @@ void cache_register(struct cache_detail *cd)
 		cd->flush_ent =  p;
  		if (p) {
  			p->proc_fops = &cache_flush_operations;
- 			p->owner = THIS_MODULE;
+ 			p->owner = cd->owner;
  			p->data = cd;
  		}
  
@@ -192,7 +312,7 @@ void cache_register(struct cache_detail *cd)
 			cd->channel_ent = p;
 			if (p) {
 				p->proc_fops = &cache_file_operations;
-				p->owner = THIS_MODULE;
+				p->owner = cd->owner;
 				p->data = cd;
 			}
 		}
@@ -202,7 +322,7 @@ void cache_register(struct cache_detail *cd)
 			cd->content_ent = p;
  			if (p) {
  				p->proc_fops = &content_file_operations;
- 				p->owner = THIS_MODULE;
+ 				p->owner = cd->owner;
  				p->data = cd;
  			}
  		}
@@ -219,7 +339,7 @@ void cache_register(struct cache_detail *cd)
 	spin_unlock(&cache_list_lock);
 
 	/* start the cleaning process */
-	schedule_work(&cache_cleaner);
+	schedule_delayed_work(&cache_cleaner, 0);
 }
 
 int cache_unregister(struct cache_detail *cd)
@@ -256,39 +376,13 @@ int cache_unregister(struct cache_detail *cd)
 	return 0;
 }
 
-struct cache_detail *cache_find(char *name)
-{
-	struct list_head *l;
-
-	spin_lock(&cache_list_lock);
-	list_for_each(l, &cache_list) {
-		struct cache_detail *cd = list_entry(l, struct cache_detail, others);
-		
-		if (strcmp(cd->name, name)==0) {
-			atomic_inc(&cd->inuse);
-			spin_unlock(&cache_list_lock);
-			return cd;
-		}
-	}
-	spin_unlock(&cache_list_lock);
-	return NULL;
-}
-
-/* cache_drop must be called on any cache returned by
- * cache_find, after it has been used
- */
-void cache_drop(struct cache_detail *detail)
-{
-	atomic_dec(&detail->inuse);
-}
-
 /* clean cache tries to find something to clean
  * and cleans it.
  * It returns 1 if it cleaned something,
  *            0 if it didn't find anything this time
  *           -1 if it fell off the end of the list.
  */
-int cache_clean(void)
+static int cache_clean(void)
 {
 	int rv = 0;
 	struct list_head *next;
@@ -344,12 +438,10 @@ int cache_clean(void)
 			if (test_and_clear_bit(CACHE_PENDING, &ch->flags))
 				queue_loose(current_detail, ch);
 
-			if (!atomic_read(&ch->refcnt))
+			if (atomic_read(&ch->ref.refcount) == 1)
 				break;
 		}
 		if (ch) {
-			cache_get(ch);
-			clear_bit(CACHE_HASHED, &ch->flags);
 			*cp = ch->next;
 			ch->next = NULL;
 			current_detail->entries--;
@@ -361,7 +453,7 @@ int cache_clean(void)
 			current_index ++;
 		spin_unlock(&cache_list_lock);
 		if (ch)
-			d->cache_put(ch, d);
+			cache_put(ch, d);
 	} else
 		spin_unlock(&cache_list_lock);
 
@@ -371,7 +463,7 @@ int cache_clean(void)
 /*
  * We want to regularly clean the cache, so we need to schedule some work ...
  */
-static void do_cache_clean(void *data)
+static void do_cache_clean(struct work_struct *work)
 {
 	int delay = 5;
 	if (cache_clean() == -1)
@@ -400,9 +492,10 @@ void cache_flush(void)
 
 void cache_purge(struct cache_detail *detail)
 {
-	detail->flush_time = get_seconds()+1;
+	detail->flush_time = LONG_MAX;
 	detail->nextcheck = get_seconds();
 	cache_flush();
+	detail->flush_time = 1;
 }
 
 
@@ -427,19 +520,26 @@ void cache_purge(struct cache_detail *detail)
 
 #define	DFR_MAX	300	/* ??? */
 
-spinlock_t cache_defer_lock = SPIN_LOCK_UNLOCKED;
+static DEFINE_SPINLOCK(cache_defer_lock);
 static LIST_HEAD(cache_defer_list);
 static struct list_head cache_defer_hash[DFR_HASHSIZE];
 static int cache_defer_cnt;
 
-void cache_defer_req(struct cache_req *req, struct cache_head *item)
+static int cache_defer_req(struct cache_req *req, struct cache_head *item)
 {
 	struct cache_deferred_req *dreq;
 	int hash = DFR_HASH(item);
 
+	if (cache_defer_cnt >= DFR_MAX) {
+		/* too much in the cache, randomly drop this one,
+		 * or continue and drop the oldest below
+		 */
+		if (net_random()&1)
+			return -ETIMEDOUT;
+	}
 	dreq = req->defer(req);
 	if (dreq == NULL)
-		return;
+		return -ETIMEDOUT;
 
 	dreq->item = item;
 	dreq->recv_time = get_seconds();
@@ -455,17 +555,8 @@ void cache_defer_req(struct cache_req *req, struct cache_head *item)
 	/* it is in, now maybe clean up */
 	dreq = NULL;
 	if (++cache_defer_cnt > DFR_MAX) {
-		/* too much in the cache, randomly drop
-		 * first or last
-		 */
-		if (net_random()&1) 
-			dreq = list_entry(cache_defer_list.next,
-					  struct cache_deferred_req,
-					  recent);
-		else
-			dreq = list_entry(cache_defer_list.prev,
-					  struct cache_deferred_req,
-					  recent);
+		dreq = list_entry(cache_defer_list.prev,
+				  struct cache_deferred_req, recent);
 		list_del(&dreq->recent);
 		list_del(&dreq->hash);
 		cache_defer_cnt--;
@@ -476,13 +567,14 @@ void cache_defer_req(struct cache_req *req, struct cache_head *item)
 		/* there was one too many */
 		dreq->revisit(dreq, 1);
 	}
-	if (test_bit(CACHE_VALID, &item->flags)) {
+	if (!test_bit(CACHE_PENDING, &item->flags)) {
 		/* must have just been validated... */
 		cache_revisit_request(item);
 	}
+	return 0;
 }
 
-void cache_revisit_request(struct cache_head *item)
+static void cache_revisit_request(struct cache_head *item)
 {
 	struct cache_deferred_req *dreq;
 	struct list_head pending;
@@ -555,8 +647,8 @@ void cache_clean_deferred(void *owner)
  *
  */
 
-static spinlock_t queue_lock = SPIN_LOCK_UNLOCKED;
-static DECLARE_MUTEX(queue_io_sem);
+static DEFINE_SPINLOCK(queue_lock);
+static DEFINE_MUTEX(queue_io_mutex);
 
 struct cache_queue {
 	struct list_head	list;
@@ -579,16 +671,13 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
 {
 	struct cache_reader *rp = filp->private_data;
 	struct cache_request *rq;
-	struct cache_detail *cd = PDE(filp->f_dentry->d_inode)->data;
+	struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
 	int err;
 
-	if (ppos != &filp->f_pos)
-		return -ESPIPE;
-
 	if (count == 0)
 		return 0;
 
-	down(&queue_io_sem); /* protect against multiple concurrent
+	mutex_lock(&queue_io_mutex); /* protect against multiple concurrent
 			      * readers on this file */
  again:
 	spin_lock(&queue_lock);
@@ -601,13 +690,12 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
 	}
 	if (rp->q.list.next == &cd->queue) {
 		spin_unlock(&queue_lock);
-		up(&queue_io_sem);
-		if (rp->offset)
-			BUG();
+		mutex_unlock(&queue_io_mutex);
+		BUG_ON(rp->offset);
 		return 0;
 	}
 	rq = container_of(rp->q.list.next, struct cache_request, q.list);
-	if (rq->q.reader) BUG();
+	BUG_ON(rq->q.reader);
 	if (rp->offset == 0)
 		rq->readers++;
 	spin_unlock(&queue_lock);
@@ -641,7 +729,7 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
 		    !test_bit(CACHE_PENDING, &rq->item->flags)) {
 			list_del(&rq->q.list);
 			spin_unlock(&queue_lock);
-			cd->cache_put(rq->item, cd);
+			cache_put(rq->item, cd);
 			kfree(rq->buf);
 			kfree(rq);
 		} else
@@ -649,31 +737,28 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
 	}
 	if (err == -EAGAIN)
 		goto again;
-	up(&queue_io_sem);
+	mutex_unlock(&queue_io_mutex);
 	return err ? err :  count;
 }
 
-static char write_buf[8192]; /* protected by queue_io_sem */
+static char write_buf[8192]; /* protected by queue_io_mutex */
 
 static ssize_t
 cache_write(struct file *filp, const char __user *buf, size_t count,
 	    loff_t *ppos)
 {
 	int err;
-	struct cache_detail *cd = PDE(filp->f_dentry->d_inode)->data;
-
-	if (ppos != &filp->f_pos)
-		return -ESPIPE;
+	struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
 
 	if (count == 0)
 		return 0;
 	if (count >= sizeof(write_buf))
 		return -EINVAL;
 
-	down(&queue_io_sem);
+	mutex_lock(&queue_io_mutex);
 
 	if (copy_from_user(write_buf, buf, count)) {
-		up(&queue_io_sem);
+		mutex_unlock(&queue_io_mutex);
 		return -EFAULT;
 	}
 	write_buf[count] = '\0';
@@ -682,7 +767,7 @@ cache_write(struct file *filp, const char __user *buf, size_t count,
 	else
 		err = -EINVAL;
 
-	up(&queue_io_sem);
+	mutex_unlock(&queue_io_mutex);
 	return err ? err : count;
 }
 
@@ -694,7 +779,7 @@ cache_poll(struct file *filp, poll_table *wait)
 	unsigned int mask;
 	struct cache_reader *rp = filp->private_data;
 	struct cache_queue *cq;
-	struct cache_detail *cd = PDE(filp->f_dentry->d_inode)->data;
+	struct cache_detail *cd = PDE(filp->f_path.dentry->d_inode)->data;
 
 	poll_wait(filp, &queue_wait, wait);
 
@@ -751,6 +836,7 @@ cache_open(struct inode *inode, struct file *filp)
 {
 	struct cache_reader *rp = NULL;
 
+	nonseekable_open(inode, filp);
 	if (filp->f_mode & FMODE_READ) {
 		struct cache_detail *cd = PDE(inode)->data;
 
@@ -823,10 +909,10 @@ static void queue_loose(struct cache_detail *detail, struct cache_head *ch)
 			if (cr->item != ch)
 				continue;
 			if (cr->readers != 0)
-				break;
+				continue;
 			list_del(&cr->q.list);
 			spin_unlock(&queue_lock);
-			detail->cache_put(cr->item, detail);
+			cache_put(cr->item, detail);
 			kfree(cr->buf);
 			kfree(cr);
 			return;
@@ -906,7 +992,7 @@ void qword_addhex(char **bpp, int *lp, char *buf, int blen)
 	*lp = len;
 }
 
-void warn_no_listener(struct cache_detail *detail)
+static void warn_no_listener(struct cache_detail *detail)
 {
 	if (detail->last_warn != detail->last_close) {
 		detail->last_warn = detail->last_close;
@@ -1111,8 +1197,8 @@ static int c_show(struct seq_file *m, void *p)
 		return cd->cache_show(m, cd, NULL);
 
 	ifdebug(CACHE)
-		seq_printf(m, "# expiry=%ld refcnt=%d\n",
-			   cp->expiry_time, atomic_read(&cp->refcnt));
+		seq_printf(m, "# expiry=%ld refcnt=%d flags=%lx\n",
+			   cp->expiry_time, atomic_read(&cp->ref.refcount), cp->flags);
 	cache_get(cp);
 	if (cache_check(cd, cp, NULL))
 		/* cache_check does a cache_put on failure */
@@ -1123,7 +1209,7 @@ static int c_show(struct seq_file *m, void *p)
 	return cd->cache_show(m, cd, cp);
 }
 
-struct seq_operations cache_content_op = {
+static struct seq_operations cache_content_op = {
 	.start	= c_start,
 	.next	= c_next,
 	.stop	= c_stop,
@@ -1169,7 +1255,7 @@ static struct file_operations content_file_operations = {
 static ssize_t read_flush(struct file *file, char __user *buf,
 			    size_t count, loff_t *ppos)
 {
-	struct cache_detail *cd = PDE(file->f_dentry->d_inode)->data;
+	struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
 	char tbuf[20];
 	unsigned long p = *ppos;
 	int len;
@@ -1190,7 +1276,7 @@ static ssize_t read_flush(struct file *file, char __user *buf,
 static ssize_t write_flush(struct file * file, const char __user * buf,
 			     size_t count, loff_t *ppos)
 {
-	struct cache_detail *cd = PDE(file->f_dentry->d_inode)->data;
+	struct cache_detail *cd = PDE(file->f_path.dentry->d_inode)->data;
 	char tbuf[20];
 	char *ep;
 	long flushtime;
@@ -1212,6 +1298,7 @@ static ssize_t write_flush(struct file * file, const char __user * buf,
 }
 
 static struct file_operations cache_flush_operations = {
+	.open		= nonseekable_open,
 	.read		= read_flush,
 	.write		= write_flush,
 };