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authorTrond Myklebust <trondmy@gmail.com>2018-10-01 10:41:51 -0400
committerJ. Bruce Fields <bfields@redhat.com>2018-10-29 16:58:04 -0400
commitd48cf356a13073853f19be6ca5ebbecfc2762ebe (patch)
tree94c1c887f4b40d27666b4bd2b9205c9a7dcc78af
parenta6482733bc98aa04b44c91e744bbcbfb29f8d3ee (diff)
downloadlinux-d48cf356a13073853f19be6ca5ebbecfc2762ebe.tar.gz
SUNRPC: Remove non-RCU protected lookup
Clean up the cache code by removing the non-RCU protected lookup. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--Documentation/filesystems/nfs/rpc-cache.txt6
-rw-r--r--include/linux/sunrpc/cache.h6
-rw-r--r--net/sunrpc/cache.c61
3 files changed, 7 insertions, 66 deletions
diff --git a/Documentation/filesystems/nfs/rpc-cache.txt b/Documentation/filesystems/nfs/rpc-cache.txt
index ebcaaee21616..c4dac829db0f 100644
--- a/Documentation/filesystems/nfs/rpc-cache.txt
+++ b/Documentation/filesystems/nfs/rpc-cache.txt
@@ -84,7 +84,7 @@ Creating a Cache
A message from user space has arrived to fill out a
cache entry. It is in 'buf' of length 'len'.
cache_parse should parse this, find the item in the
- cache with sunrpc_cache_lookup, and update the item
+ cache with sunrpc_cache_lookup_rcu, and update the item
with sunrpc_cache_update.
@@ -95,7 +95,7 @@ Creating a Cache
Using a cache
-------------
-To find a value in a cache, call sunrpc_cache_lookup passing a pointer
+To find a value in a cache, call sunrpc_cache_lookup_rcu passing a pointer
to the cache_head in a sample item with the 'key' fields filled in.
This will be passed to ->match to identify the target entry. If no
entry is found, a new entry will be create, added to the cache, and
@@ -116,7 +116,7 @@ item does become valid, the deferred copy of the request will be
revisited (->revisit). It is expected that this method will
reschedule the request for processing.
-The value returned by sunrpc_cache_lookup can also be passed to
+The value returned by sunrpc_cache_lookup_rcu can also be passed to
sunrpc_cache_update to set the content for the item. A second item is
passed which should hold the content. If the item found by _lookup
has valid data, then it is discarded and a new item is created. This
diff --git a/include/linux/sunrpc/cache.h b/include/linux/sunrpc/cache.h
index cf3e17ee2786..c3d67e893430 100644
--- a/include/linux/sunrpc/cache.h
+++ b/include/linux/sunrpc/cache.h
@@ -171,9 +171,6 @@ extern struct cache_head *
sunrpc_cache_lookup_rcu(struct cache_detail *detail,
struct cache_head *key, int hash);
extern struct cache_head *
-sunrpc_cache_lookup(struct cache_detail *detail,
- struct cache_head *key, int hash);
-extern struct cache_head *
sunrpc_cache_update(struct cache_detail *detail,
struct cache_head *new, struct cache_head *old, int hash);
@@ -233,9 +230,6 @@ extern void sunrpc_cache_unregister_pipefs(struct cache_detail *);
extern void sunrpc_cache_unhash(struct cache_detail *, struct cache_head *);
/* Must store cache_detail in seq_file->private if using next three functions */
-extern void *cache_seq_start(struct seq_file *file, loff_t *pos);
-extern void *cache_seq_next(struct seq_file *file, void *p, loff_t *pos);
-extern void cache_seq_stop(struct seq_file *file, void *p);
extern void *cache_seq_start_rcu(struct seq_file *file, loff_t *pos);
extern void *cache_seq_next_rcu(struct seq_file *file, void *p, loff_t *pos);
extern void cache_seq_stop_rcu(struct seq_file *file, void *p);
diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 7593afed9036..593cf8607414 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -75,27 +75,6 @@ static struct cache_head *sunrpc_cache_find_rcu(struct cache_detail *detail,
return NULL;
}
-static struct cache_head *sunrpc_cache_find(struct cache_detail *detail,
- struct cache_head *key, int hash)
-{
- struct hlist_head *head = &detail->hash_table[hash];
- struct cache_head *tmp;
-
- read_lock(&detail->hash_lock);
- 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. */
- break;
- cache_get(tmp);
- read_unlock(&detail->hash_lock);
- return tmp;
- }
- }
- read_unlock(&detail->hash_lock);
- return NULL;
-}
-
static struct cache_head *sunrpc_cache_add_entry(struct cache_detail *detail,
struct cache_head *key,
int hash)
@@ -154,20 +133,6 @@ struct cache_head *sunrpc_cache_lookup_rcu(struct cache_detail *detail,
}
EXPORT_SYMBOL_GPL(sunrpc_cache_lookup_rcu);
-struct cache_head *sunrpc_cache_lookup(struct cache_detail *detail,
- struct cache_head *key, int hash)
-{
- struct cache_head *ret;
-
- ret = sunrpc_cache_find(detail, key, hash);
- if (ret)
- return ret;
- /* Didn't find anything, insert an empty entry */
- return sunrpc_cache_add_entry(detail, key, hash);
-}
-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,
@@ -1369,17 +1334,7 @@ static void *__cache_seq_start(struct seq_file *m, loff_t *pos)
struct cache_head, cache_list);
}
-void *cache_seq_start(struct seq_file *m, loff_t *pos)
- __acquires(cd->hash_lock)
-{
- struct cache_detail *cd = m->private;
-
- read_lock(&cd->hash_lock);
- return __cache_seq_start(m, pos);
-}
-EXPORT_SYMBOL_GPL(cache_seq_start);
-
-void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
+static void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
{
struct cache_head *ch = p;
int hash = (*pos >> 32);
@@ -1411,14 +1366,6 @@ void *cache_seq_next(struct seq_file *m, void *p, loff_t *pos)
}
EXPORT_SYMBOL_GPL(cache_seq_next);
-void cache_seq_stop(struct seq_file *m, void *p)
- __releases(cd->hash_lock)
-{
- struct cache_detail *cd = m->private;
- read_unlock(&cd->hash_lock);
-}
-EXPORT_SYMBOL_GPL(cache_seq_stop);
-
void *cache_seq_start_rcu(struct seq_file *m, loff_t *pos)
__acquires(RCU)
{
@@ -1466,9 +1413,9 @@ static int c_show(struct seq_file *m, void *p)
}
static const struct seq_operations cache_content_op = {
- .start = cache_seq_start,
- .next = cache_seq_next,
- .stop = cache_seq_stop,
+ .start = cache_seq_start_rcu,
+ .next = cache_seq_next_rcu,
+ .stop = cache_seq_stop_rcu,
.show = c_show,
};