X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=net%2Fsunrpc%2Fcache.c;h=7026b0866b7b0d50b0003b15bb14fde24a569a65;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=900f5bc7e3366480426f0674ec4a2ca5c2113f7d;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 900f5bc7e..7026b0866 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -36,16 +37,139 @@ static void cache_defer_req(struct cache_req *req, struct cache_head *item); static void cache_revisit_request(struct cache_head *item); -void cache_init(struct cache_head *h) +static void cache_init(struct cache_head *h) { time_t now = get_seconds(); h->next = NULL; h->flags = 0; - atomic_set(&h->refcnt, 1); + 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; + cache_init(new); + + 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; + } + } + detail->init(new, key); + 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); /* @@ -93,7 +217,8 @@ 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; @@ -109,25 +234,11 @@ int cache_check(struct cache_detail *detail, if (rv == -EAGAIN) cache_defer_req(rqstp, h); - 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 @@ -177,7 +288,7 @@ 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, @@ -185,7 +296,7 @@ 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; } @@ -195,7 +306,7 @@ 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; } } @@ -205,7 +316,7 @@ 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; } } @@ -321,7 +432,7 @@ static int cache_clean(void) if (test_and_clear_bit(CACHE_PENDING, &ch->flags)) queue_loose(current_detail, ch); - if (atomic_read(&ch->refcnt) == 1) + if (atomic_read(&ch->ref.refcount) == 1) break; } if (ch) { @@ -336,7 +447,7 @@ static 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); @@ -452,7 +563,7 @@ static 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); } @@ -532,7 +643,7 @@ void cache_clean_deferred(void *owner) */ static DEFINE_SPINLOCK(queue_lock); -static DECLARE_MUTEX(queue_io_sem); +static DEFINE_MUTEX(queue_io_mutex); struct cache_queue { struct list_head list; @@ -561,7 +672,7 @@ cache_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos) 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); @@ -574,13 +685,12 @@ 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); @@ -614,7 +724,7 @@ 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 @@ -622,11 +732,11 @@ 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, @@ -640,10 +750,10 @@ cache_write(struct file *filp, const char __user *buf, size_t count, 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'; @@ -652,7 +762,7 @@ 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; } @@ -794,10 +904,10 @@ 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; @@ -1082,8 +1192,8 @@ 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 */