NFS: Convert struct nfs_open_context to use a kref

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

2 files changed, 25 insertions, 18 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e7d2bba900b5..01fc8ab0c562 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -461,7 +461,6 @@ static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, str
 
         ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
         if (ctx != NULL) {
-                atomic_set(&ctx->count, 1);
                 ctx->path.dentry = dget(dentry);
                 ctx->path.mnt = mntget(mnt);
                 ctx->cred = get_rpccred(cred);
@@ -469,6 +468,7 @@ static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, str
                 ctx->lockowner = current->files;
                 ctx->error = 0;
                 ctx->dir_cookie = 0;
+                kref_init(&ctx->kref);
         }
         return ctx;
 }
@@ -476,27 +476,33 @@ static struct nfs_open_context *alloc_nfs_open_context(struct vfsmount *mnt, str
 struct nfs_open_context *get_nfs_open_context(struct nfs_open_context *ctx)
 {
         if (ctx != NULL)
-                atomic_inc(&ctx->count);
+                kref_get(&ctx->kref);
         return ctx;
 }
 
-void put_nfs_open_context(struct nfs_open_context *ctx)
+static void nfs_free_open_context(struct kref *kref)
 {
-        if (atomic_dec_and_test(&ctx->count)) {
-                if (!list_empty(&ctx->list)) {
-                        struct inode *inode = ctx->path.dentry->d_inode;
-                        spin_lock(&inode->i_lock);
-                        list_del(&ctx->list);
-                        spin_unlock(&inode->i_lock);
-                }
-                if (ctx->state != NULL)
-                        nfs4_close_state(&ctx->path, ctx->state, ctx->mode);
-                if (ctx->cred != NULL)
-                        put_rpccred(ctx->cred);
-                dput(ctx->path.dentry);
-                mntput(ctx->path.mnt);
-                kfree(ctx);
+        struct nfs_open_context *ctx = container_of(kref,
+                        struct nfs_open_context, kref);
+
+        if (!list_empty(&ctx->list)) {
+                struct inode *inode = ctx->path.dentry->d_inode;
+                spin_lock(&inode->i_lock);
+                list_del(&ctx->list);
+                spin_unlock(&inode->i_lock);
         }
+        if (ctx->state != NULL)
+                nfs4_close_state(&ctx->path, ctx->state, ctx->mode);
+        if (ctx->cred != NULL)
+                put_rpccred(ctx->cred);
+        dput(ctx->path.dentry);
+        mntput(ctx->path.mnt);
+        kfree(ctx);
+}
+
+void put_nfs_open_context(struct nfs_open_context *ctx)
+{
+        kref_put(&ctx->kref, nfs_free_open_context);
 }
 
 /*
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 750708ccd708..bf24151d63be 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -30,6 +30,7 @@
 #ifdef __KERNEL__
 
 #include <linux/in.h>
+#include <linux/kref.h>
 #include <linux/mm.h>
 #include <linux/namei.h>
 #include <linux/pagemap.h>
@@ -70,7 +71,7 @@ struct nfs_access_entry {
 
 struct nfs4_state;
 struct nfs_open_context {
-        atomic_t count;
+        struct kref kref;
         struct path path;
         struct rpc_cred *cred;
         struct nfs4_state *state;