aboutsummaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorJ. Bruce Fields <bfields@citi.umich.edu>2009-02-22 14:51:34 -0800
committerJ. Bruce Fields <bfields@citi.umich.edu>2009-03-18 17:38:38 -0400
commit8b671b80707e4fc76adfe4387df07b3be1007c1e (patch)
treed9dafb3a1174dfeb84f72ba56a04625204aab415 /fs
parentd7fdcfe0aaaf6dffca6fa857bab374182fe7ca8b (diff)
nfsd4: remove use of mutex for file_hashtable
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@citi.umich.edu> Cc: Alexandros Batsakis <batsakis@netapp.com> Reviewed-by: Benny Halevy <bhalevy@panasas.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/nfsd/nfs4callback.c2
-rw-r--r--fs/nfsd/nfs4state.c47
2 files changed, 23 insertions, 26 deletions
diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c
index 3fd7136321c..5dcd38e5f13 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 89e575e7dae..54651aa4579 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;
@@ -116,33 +120,23 @@ 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);
- list_del(&fp->fi_hash);
- iput(fp->fi_inode);
- kmem_cache_free(file_slab, fp);
-}
-
static inline void
put_nfs4_file(struct nfs4_file *fi)
{
- kref_put(&fi->fi_ref, free_nfs4_file);
+ if (atomic_dec_and_lock(&fi->fi_ref, &recall_lock)) {
+ list_del(&fi->fi_hash);
+ spin_unlock(&recall_lock);
+ iput(fi->fi_inode);
+ kmem_cache_free(file_slab, fi);
+ }
}
static inline void
get_nfs4_file(struct nfs4_file *fi)
{
- kref_get(&fi->fi_ref);
+ atomic_inc(&fi->fi_ref);
}
static int num_delegations;
@@ -1000,11 +994,13 @@ alloc_init_file(struct inode *ino)
fp = kmem_cache_alloc(file_slab, GFP_KERNEL);
if (fp) {
- kref_init(&fp->fi_ref);
+ atomic_set(&fp->fi_ref, 1);
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 +1173,15 @@ 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) {
get_nfs4_file(fp);
+ spin_unlock(&recall_lock);
return fp;
}
}
+ spin_unlock(&recall_lock);
return NULL;
}