From: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
As part of reducing the scope of the client_mutex, and in order to
remove the need for mutexes from the callback code (so that callbacks
can be done as asynchronous rpc calls), move manipulations of the
file_hashtable under the recall_lock.
Update the relevant comments while we're here.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
Cc: Alexandros Batsakis <batsakis@xxxxxxxxxx>
---
fs/nfsd/nfs4callback.c | 2 --
fs/nfsd/nfs4state.c | 29 +++++++++++++++++------------
2 files changed, 17 insertions(+), 14 deletions(-)
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 3fd7136..5dcd38e 100644
--- a/fs/nfsd/nfs4callback.c
+++ b/fs/nfsd/nfs4callback.c
@@ -491,8 +491,6 @@ out_put_cred:
* or deleg_return.
*/
put_nfs4_client(clp);
- nfs4_lock_state();
nfs4_put_delegation(dp);
- nfs4_unlock_state();
return;
}
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 56e81f9..2f4cb9a 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -78,14 +78,18 @@ static struct nfs4_delegation * find_delegation_stateid(struct inode *ino, state
static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
static void nfs4_set_recdir(char *recdir);
-/* Locking:
- *
- * client_mutex:
- * protects clientid_hashtbl[], clientstr_hashtbl[],
- * unconfstr_hashtbl[], uncofid_hashtbl[].
- */
+/* Locking: */
+
+/* Currently used for almost all code touching nfsv4 state: */
static DEFINE_MUTEX(client_mutex);
+/*
+ * Currently used for the del_recall_lru and file hash table. In an
+ * effort to decrease the scope of the client_mutex, this spinlock may
+ * eventually cover more:
+ */
+static DEFINE_SPINLOCK(recall_lock);
+
static struct kmem_cache *stateowner_slab = NULL;
static struct kmem_cache *file_slab = NULL;
static struct kmem_cache *stateid_slab = NULL;
@@ -116,19 +120,15 @@ opaque_hashval(const void *ptr, int nbytes)
return x;
}
-/*
- * Delegation state
- */
-
-/* recall_lock protects the del_recall_lru */
-static DEFINE_SPINLOCK(recall_lock);
static struct list_head del_recall_lru;
static void
free_nfs4_file(struct kref *kref)
{
struct nfs4_file *fp = container_of(kref, struct nfs4_file, fi_ref);
+ spin_lock(&recall_lock);
list_del(&fp->fi_hash);
+ spin_unlock(&recall_lock);
iput(fp->fi_inode);
kmem_cache_free(file_slab, fp);
}
@@ -1004,7 +1004,9 @@ alloc_init_file(struct inode *ino)
INIT_LIST_HEAD(&fp->fi_hash);
INIT_LIST_HEAD(&fp->fi_stateids);
INIT_LIST_HEAD(&fp->fi_delegations);
+ spin_lock(&recall_lock);
list_add(&fp->fi_hash, &file_hashtbl[hashval]);
+ spin_unlock(&recall_lock);
fp->fi_inode = igrab(ino);
fp->fi_id = current_fileid++;
fp->fi_had_conflict = false;
@@ -1177,12 +1179,15 @@ find_file(struct inode *ino)
unsigned int hashval = file_hashval(ino);
struct nfs4_file *fp;
+ spin_lock(&recall_lock);
list_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
if (fp->fi_inode == ino) {
+ spin_unlock(&recall_lock);
get_nfs4_file(fp);
return fp;
}
}
+ spin_unlock(&recall_lock);
return NULL;
}
--
1.6.0.4
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
