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authorNiels de Vos <ndevos@redhat.com>2015-05-31 14:39:51 +0200
committerNiels de Vos <ndevos@redhat.com>2015-06-28 10:37:04 -0700
commit67f7562b5cc9e42774d1dc569471f86f61eef040 (patch)
tree193d756065ad454a78c8d9e98aa0d1995b4dde09 /xlators
parent5f76ff1beaaf1fd1c85c43a166c289f9094a379b (diff)
nfs: add a gf_lock_t for the auth_cache->cache_dict
This is the 1st step towards implementing reference counters for the auth_cache_entry structure. Access to the structures should always be done atomically, but this can not be guaranteed by the a dict. Change-Id: Ic165221d72f11832177976c989823d861cf12f01 BUG: 1226717 Signed-off-by: Niels de Vos <ndevos@redhat.com> Reviewed-on: http://review.gluster.org/11021 Tested-by: NetBSD Build System <jenkins@build.gluster.org> Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: jiffin tony Thottan <jthottan@redhat.com>
Diffstat (limited to 'xlators')
-rw-r--r--xlators/nfs/server/src/auth-cache.c165
-rw-r--r--xlators/nfs/server/src/auth-cache.h1
2 files changed, 126 insertions, 40 deletions
diff --git a/xlators/nfs/server/src/auth-cache.c b/xlators/nfs/server/src/auth-cache.c
index 67752ae6556..ebaf72594b0 100644
--- a/xlators/nfs/server/src/auth-cache.c
+++ b/xlators/nfs/server/src/auth-cache.c
@@ -76,6 +76,7 @@ auth_cache_init (time_t ttl_sec)
goto out;
}
+ LOCK_INIT (&cache->lock);
cache->ttl_sec = ttl_sec;
out:
return cache;
@@ -87,7 +88,7 @@ out:
* @return: Pointer to an allocated auth cache entry, NULL if allocation
* failed.
*/
-struct auth_cache_entry *
+static struct auth_cache_entry *
auth_cache_entry_init ()
{
struct auth_cache_entry *entry = NULL;
@@ -101,6 +102,102 @@ auth_cache_entry_init ()
}
/**
+ * auth_cache_add -- Add an auth_cache_entry to the cache->dict
+ *
+ * @return: 0 on success, non-zero otherwise.
+ */
+static int
+auth_cache_add (struct auth_cache *cache, char *hashkey,
+ struct auth_cache_entry *entry)
+{
+ int ret = -1;
+ data_t *entry_data = NULL;
+
+ GF_VALIDATE_OR_GOTO (GF_NFS, cache, out);
+ GF_VALIDATE_OR_GOTO (GF_NFS, cache->cache_dict, out);
+
+ entry_data = bin_to_data (entry, sizeof (*entry));
+ if (!entry_data) {
+ goto out;
+ }
+
+ LOCK (&cache->lock);
+ {
+ ret = dict_set (cache->cache_dict, hashkey, entry_data);
+ }
+ UNLOCK (&cache->lock);
+
+out:
+ return ret;
+}
+
+/**
+ * _auth_cache_expired -- Check if the auth_cache_entry has expired
+ *
+ * The auth_cache->lock should have been taken when this function is called.
+ *
+ * @return: true when the auth_cache_entry is expired, false otherwise.
+ */
+static inline int
+_auth_cache_expired (struct auth_cache *cache, struct auth_cache_entry *entry)
+{
+ return ((time (NULL) - entry->timestamp) > cache->ttl_sec);
+}
+
+/**
+ * auth_cache_get -- Get the @hashkey entry from the cache->cache_dict
+ *
+ * @cache: The auth_cache that should contain the @entry.
+ * @haskkey: The key associated with the auth_cache_entry.
+ * @entry: The found auth_cache_entry, unmodified if not found/expired.
+ *
+ * The using the cache->dict requires locking, this function takes care of
+ * that. When the entry is found, but has expired, it will be removed from the
+ * cache_dict.
+ *
+ * @return: 0 when found, ENTRY_NOT_FOUND or ENTRY_EXPIRED otherwise.
+ */
+static enum auth_cache_lookup_results
+auth_cache_get (struct auth_cache *cache, char *hashkey,
+ struct auth_cache_entry **entry)
+{
+ enum auth_cache_lookup_results ret = ENTRY_NOT_FOUND;
+ data_t *entry_data = NULL;
+ struct auth_cache_entry *lookup_res = NULL;
+
+ GF_VALIDATE_OR_GOTO (GF_NFS, cache, out);
+ GF_VALIDATE_OR_GOTO (GF_NFS, cache->cache_dict, out);
+
+ LOCK (&cache->lock);
+ {
+ entry_data = dict_get (cache->cache_dict, hashkey);
+ if (!entry_data)
+ goto unlock;
+
+ /* TODO: refcount++ on lookup_res */
+ lookup_res = (struct auth_cache_entry *)(entry_data->data);
+ if (_auth_cache_expired (cache, lookup_res)) {
+ ret = ENTRY_EXPIRED;
+
+ /* free entry and remove from the cache */
+ GF_FREE (lookup_res);
+ entry_data->data = NULL;
+ dict_del (cache->cache_dict, hashkey);
+
+ goto unlock;
+ }
+
+ *entry = lookup_res;
+ ret = ENTRY_FOUND;
+ }
+unlock:
+ UNLOCK (&cache->lock);
+
+out:
+ return ret;
+}
+
+/**
* auth_cache_lookup -- Lookup an item from the cache
*
* @cache: cache to lookup from
@@ -121,13 +218,11 @@ auth_cache_lookup (struct auth_cache *cache, struct nfs3_fh *fh,
const char *host_addr, time_t *timestamp,
gf_boolean_t *can_write)
{
- char *hashkey = NULL;
- data_t *entry_data = NULL;
- struct auth_cache_entry *lookup_res = NULL;
- int ret = ENTRY_NOT_FOUND;
+ char *hashkey = NULL;
+ struct auth_cache_entry *lookup_res = NULL;
+ enum auth_cache_lookup_results ret = ENTRY_NOT_FOUND;
GF_VALIDATE_OR_GOTO (GF_NFS, cache, out);
- GF_VALIDATE_OR_GOTO (GF_NFS, cache->cache_dict, out);
GF_VALIDATE_OR_GOTO (GF_NFS, fh, out);
GF_VALIDATE_OR_GOTO (GF_NFS, host_addr, out);
GF_VALIDATE_OR_GOTO (GF_NFS, timestamp, out);
@@ -139,31 +234,25 @@ auth_cache_lookup (struct auth_cache *cache, struct nfs3_fh *fh,
goto out;
}
- entry_data = dict_get (cache->cache_dict, hashkey);
- if (!entry_data) {
+ ret = auth_cache_get (cache, hashkey, &lookup_res);
+ switch (ret) {
+ case ENTRY_FOUND:
+ *timestamp = lookup_res->timestamp;
+ *can_write = lookup_res->item->opts->rw;
+ /* TODO: refcount-- lookup_res */
+ break;
+
+ case ENTRY_NOT_FOUND:
gf_msg_debug (GF_NFS, 0, "could not find entry for %s",
host_addr);
- goto out;
- }
+ break;
- lookup_res = (struct auth_cache_entry *)(entry_data->data);
-
- if ((time (NULL) - lookup_res->timestamp) > cache->ttl_sec) {
+ case ENTRY_EXPIRED:
gf_msg_debug (GF_NFS, 0, "entry for host %s has expired",
host_addr);
- GF_FREE (lookup_res);
- entry_data->data = NULL;
- /* Remove from the cache */
- dict_del (cache->cache_dict, hashkey);
-
- ret = ENTRY_EXPIRED;
- goto out;
+ break;
}
- *timestamp = lookup_res->timestamp;
- *can_write = lookup_res->item->opts->rw;
-
- ret = ENTRY_FOUND;
out:
GF_FREE (hashkey);
@@ -180,14 +269,19 @@ void
auth_cache_purge (struct auth_cache *cache)
{
dict_t *new_cache_dict = dict_new ();
- dict_t *old_cache_dict = cache->cache_dict;
+ dict_t *old_cache_dict = NULL;
- if (!cache)
+ if (!cache || !new_cache_dict)
goto out;
- (void)__sync_lock_test_and_set (&cache->cache_dict, new_cache_dict);
-
- dict_unref (old_cache_dict);
+ LOCK (&cache->lock);
+ {
+ old_cache_dict = cache->cache_dict;
+ (void) __sync_lock_test_and_set (&cache->cache_dict,
+ new_cache_dict);
+ dict_unref (old_cache_dict);
+ }
+ UNLOCK (&cache->lock);
out:
return;
}
@@ -304,17 +398,8 @@ cache_nfs_fh (struct auth_cache *cache, struct nfs3_fh *fh,
entry->timestamp = time (NULL);
entry->item = export_item;
- /* The cache entry will simply be the time that the entry
- * was cached.
- */
- entry_data = bin_to_data (entry, sizeof (*entry));
- if (!entry_data) {
- GF_FREE (entry);
- goto out;
- }
-
- ret = dict_set (cache->cache_dict, hashkey, entry_data);
- if (ret == -1) {
+ ret = auth_cache_add (cache, hashkey, entry);
+ if (ret) {
GF_FREE (entry);
goto out;
}
diff --git a/xlators/nfs/server/src/auth-cache.h b/xlators/nfs/server/src/auth-cache.h
index 5f2f03c1cb8..a3ea5a43ded 100644
--- a/xlators/nfs/server/src/auth-cache.h
+++ b/xlators/nfs/server/src/auth-cache.h
@@ -22,6 +22,7 @@
#include "nfs3.h"
struct auth_cache {
+ gf_lock_t lock; /* locking for the dict (and entries) */
dict_t *cache_dict; /* Dict holding fh -> authcache_entry */
time_t ttl_sec; /* TTL of the auth cache in seconds */
};