diff options
Diffstat (limited to 'net/sunrpc/cache.c')
| -rw-r--r-- | net/sunrpc/cache.c | 53 |
1 files changed, 40 insertions, 13 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index 4a2340a54401..5e4f815c2b34 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -41,13 +41,16 @@ static bool 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) +static void cache_init(struct cache_head *h, struct cache_detail *detail) { time_t now = seconds_since_boot(); INIT_HLIST_NODE(&h->cache_list); h->flags = 0; kref_init(&h->ref); h->expiry_time = now + CACHE_NEW_EXPIRY; + if (now <= detail->flush_time) + /* ensure it isn't already expired */ + now = detail->flush_time + 1; h->last_refresh = now; } @@ -81,7 +84,7 @@ struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail, * we might get lose if we need to * cache_put it soon. */ - cache_init(new); + cache_init(new, detail); detail->init(new, key); write_lock(&detail->hash_lock); @@ -116,10 +119,15 @@ EXPORT_SYMBOL_GPL(sunrpc_cache_lookup); static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch); -static void cache_fresh_locked(struct cache_head *head, time_t expiry) +static void cache_fresh_locked(struct cache_head *head, time_t expiry, + struct cache_detail *detail) { + time_t now = seconds_since_boot(); + if (now <= detail->flush_time) + /* ensure it isn't immediately treated as expired */ + now = detail->flush_time + 1; head->expiry_time = expiry; - head->last_refresh = seconds_since_boot(); + head->last_refresh = now; smp_wmb(); /* paired with smp_rmb() in cache_is_valid() */ set_bit(CACHE_VALID, &head->flags); } @@ -149,7 +157,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, set_bit(CACHE_NEGATIVE, &old->flags); else detail->update(old, new); - cache_fresh_locked(old, new->expiry_time); + cache_fresh_locked(old, new->expiry_time, detail); write_unlock(&detail->hash_lock); cache_fresh_unlocked(old, detail); return old; @@ -162,7 +170,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, cache_put(old, detail); return NULL; } - cache_init(tmp); + cache_init(tmp, detail); detail->init(tmp, old); write_lock(&detail->hash_lock); @@ -173,8 +181,8 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]); detail->entries++; cache_get(tmp); - cache_fresh_locked(tmp, new->expiry_time); - cache_fresh_locked(old, 0); + cache_fresh_locked(tmp, new->expiry_time, detail); + cache_fresh_locked(old, 0, detail); write_unlock(&detail->hash_lock); cache_fresh_unlocked(tmp, detail); cache_fresh_unlocked(old, detail); @@ -219,7 +227,8 @@ static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h rv = cache_is_valid(h); if (rv == -EAGAIN) { set_bit(CACHE_NEGATIVE, &h->flags); - cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY); + cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY, + detail); rv = -ENOENT; } write_unlock(&detail->hash_lock); @@ -487,10 +496,13 @@ EXPORT_SYMBOL_GPL(cache_flush); void cache_purge(struct cache_detail *detail) { - detail->flush_time = LONG_MAX; + time_t now = seconds_since_boot(); + if (detail->flush_time >= now) + now = detail->flush_time + 1; + /* 'now' is the maximum value any 'last_refresh' can have */ + detail->flush_time = now; detail->nextcheck = seconds_since_boot(); cache_flush(); - detail->flush_time = 1; } EXPORT_SYMBOL_GPL(cache_purge); @@ -1436,6 +1448,7 @@ static ssize_t write_flush(struct file *file, const char __user *buf, { char tbuf[20]; char *bp, *ep; + time_t then, now; if (*ppos || count > sizeof(tbuf)-1) return -EINVAL; @@ -1447,8 +1460,22 @@ static ssize_t write_flush(struct file *file, const char __user *buf, return -EINVAL; bp = tbuf; - cd->flush_time = get_expiry(&bp); - cd->nextcheck = seconds_since_boot(); + then = get_expiry(&bp); + now = seconds_since_boot(); + cd->nextcheck = now; + /* Can only set flush_time to 1 second beyond "now", or + * possibly 1 second beyond flushtime. This is because + * flush_time never goes backwards so it mustn't get too far + * ahead of time. + */ + if (then >= now) { + /* Want to flush everything, so behave like cache_purge() */ + if (cd->flush_time >= now) + now = cd->flush_time + 1; + then = now; + } + + cd->flush_time = then; cache_flush(); *ppos += count; |