diff options
Diffstat (limited to 'net/sunrpc/cache.c')
-rw-r--r-- | net/sunrpc/cache.c | 128 |
1 files changed, 74 insertions, 54 deletions
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c index bd843a81afa0..af0ddd28b081 100644 --- a/net/sunrpc/cache.c +++ b/net/sunrpc/cache.c @@ -32,13 +32,13 @@ #include <linux/sunrpc/cache.h> #include <linux/sunrpc/stats.h> #include <linux/sunrpc/rpc_pipe_fs.h> +#include <trace/events/sunrpc.h> #include "netns.h" #define RPCDBG_FACILITY RPCDBG_CACHE static bool cache_defer_req(struct cache_req *req, struct cache_head *item); static void cache_revisit_request(struct cache_head *item); -static bool cache_listeners_exist(struct cache_detail *detail); static void cache_init(struct cache_head *h, struct cache_detail *detail) { @@ -65,13 +65,14 @@ static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail, rcu_read_lock(); hlist_for_each_entry_rcu(tmp, head, cache_list) { - if (detail->match(tmp, key)) { - if (cache_is_expired(detail, tmp)) - continue; - tmp = cache_get_rcu(tmp); - rcu_read_unlock(); - return tmp; - } + if (!detail->match(tmp, key)) + continue; + if (test_bit(CACHE_VALID, &tmp->flags) && + cache_is_expired(detail, tmp)) + continue; + tmp = cache_get_rcu(tmp); + rcu_read_unlock(); + return tmp; } rcu_read_unlock(); return NULL; @@ -113,18 +114,21 @@ static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail, spin_lock(&detail->hash_lock); /* check if entry appeared while we slept */ - hlist_for_each_entry_rcu(tmp, head, cache_list) { - if (detail->match(tmp, key)) { - if (cache_is_expired(detail, tmp)) { - sunrpc_begin_cache_remove_entry(tmp, detail); - freeme = tmp; - break; - } - cache_get(tmp); - spin_unlock(&detail->hash_lock); - cache_put(new, detail); - return tmp; + hlist_for_each_entry_rcu(tmp, head, cache_list, + lockdep_is_held(&detail->hash_lock)) { + if (!detail->match(tmp, key)) + continue; + if (test_bit(CACHE_VALID, &tmp->flags) && + cache_is_expired(detail, tmp)) { + sunrpc_begin_cache_remove_entry(tmp, detail); + trace_cache_entry_expired(detail, tmp); + freeme = tmp; + break; } + cache_get(tmp); + spin_unlock(&detail->hash_lock); + cache_put(new, detail); + return tmp; } hlist_add_head_rcu(&new->cache_list, head); @@ -174,6 +178,25 @@ static void cache_fresh_unlocked(struct cache_head *head, } } +static void cache_make_negative(struct cache_detail *detail, + struct cache_head *h) +{ + set_bit(CACHE_NEGATIVE, &h->flags); + trace_cache_entry_make_negative(detail, h); +} + +static void cache_entry_update(struct cache_detail *detail, + struct cache_head *h, + struct cache_head *new) +{ + if (!test_bit(CACHE_NEGATIVE, &new->flags)) { + detail->update(h, new); + trace_cache_entry_update(detail, h); + } else { + cache_make_negative(detail, h); + } +} + struct cache_head *sunrpc_cache_update(struct cache_detail *detail, struct cache_head *new, struct cache_head *old, int hash) { @@ -186,10 +209,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, if (!test_bit(CACHE_VALID, &old->flags)) { spin_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); + cache_entry_update(detail, old, new); cache_fresh_locked(old, new->expiry_time, detail); spin_unlock(&detail->hash_lock); cache_fresh_unlocked(old, detail); @@ -207,10 +227,7 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, detail->init(tmp, old); spin_lock(&detail->hash_lock); - if (test_bit(CACHE_NEGATIVE, &new->flags)) - set_bit(CACHE_NEGATIVE, &tmp->flags); - else - detail->update(tmp, new); + cache_entry_update(detail, tmp, new); hlist_add_head(&tmp->cache_list, &detail->hash_table[hash]); detail->entries++; cache_get(tmp); @@ -224,13 +241,6 @@ struct cache_head *sunrpc_cache_update(struct cache_detail *detail, } EXPORT_SYMBOL_GPL(sunrpc_cache_update); -static int cache_make_upcall(struct cache_detail *cd, struct cache_head *h) -{ - if (cd->cache_upcall) - return cd->cache_upcall(cd, h); - return sunrpc_cache_pipe_upcall(cd, h); -} - static inline int cache_is_valid(struct cache_head *h) { if (!test_bit(CACHE_VALID, &h->flags)) @@ -259,7 +269,7 @@ static int try_to_negate_entry(struct cache_detail *detail, struct cache_head *h spin_lock(&detail->hash_lock); rv = cache_is_valid(h); if (rv == -EAGAIN) { - set_bit(CACHE_NEGATIVE, &h->flags); + cache_make_negative(detail, h); cache_fresh_locked(h, seconds_since_boot()+CACHE_NEW_EXPIRY, detail); rv = -ENOENT; @@ -303,17 +313,14 @@ int cache_check(struct cache_detail *detail, (h->expiry_time != 0 && age > refresh_age/2)) { dprintk("RPC: Want update, refage=%lld, age=%lld\n", refresh_age, age); - if (!test_and_set_bit(CACHE_PENDING, &h->flags)) { - switch (cache_make_upcall(detail, h)) { - case -EINVAL: - rv = try_to_negate_entry(detail, h); - break; - case -EAGAIN: - cache_fresh_unlocked(h, detail); - break; - } - } else if (!cache_listeners_exist(detail)) + switch (detail->cache_upcall(detail, h)) { + case -EINVAL: rv = try_to_negate_entry(detail, h); + break; + case -EAGAIN: + cache_fresh_unlocked(h, detail); + break; + } } if (rv == -EAGAIN) { @@ -468,6 +475,7 @@ static int cache_clean(void) continue; sunrpc_begin_cache_remove_entry(ch, current_detail); + trace_cache_entry_expired(current_detail, ch); rv = 1; break; } @@ -1195,20 +1203,12 @@ static bool cache_listeners_exist(struct cache_detail *detail) * * Each request is at most one page long. */ -int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) +static int cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) { - char *buf; struct cache_request *crq; int ret = 0; - if (!detail->cache_request) - return -EINVAL; - - if (!cache_listeners_exist(detail)) { - warn_no_listener(detail); - return -EINVAL; - } if (test_bit(CACHE_CLEANED, &h->flags)) /* Too late to make an upcall */ return -EAGAIN; @@ -1231,6 +1231,7 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) if (test_bit(CACHE_PENDING, &h->flags)) { crq->item = cache_get(h); list_add_tail(&crq->q.list, &detail->queue); + trace_cache_entry_upcall(detail, h); } else /* Lost a race, no longer PENDING, so don't enqueue */ ret = -EAGAIN; @@ -1242,8 +1243,27 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) } return ret; } + +int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h) +{ + if (test_and_set_bit(CACHE_PENDING, &h->flags)) + return 0; + return cache_pipe_upcall(detail, h); +} EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall); +int sunrpc_cache_pipe_upcall_timeout(struct cache_detail *detail, + struct cache_head *h) +{ + if (!cache_listeners_exist(detail)) { + warn_no_listener(detail); + trace_cache_entry_no_listener(detail, h); + return -EINVAL; + } + return sunrpc_cache_pipe_upcall(detail, h); +} +EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall_timeout); + /* * parse a message from user-space and pass it * to an appropriate cache |