NFS: Create nfs_open_dir_context

nfs_opendir() created a context that held much more information than we
need for a readdir.  This patch introduces a slimmed-down
nfs_open_dir_context that contains only the cookie and the cred used for
RPC operations.  The new context will eventually be used to help detect
readdir loops.

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

1 files changed, 47 insertions, 7 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index c5c71cb62fbd..cda73814f666 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -44,6 +44,7 @@
 /* #define NFS_DEBUG_VERBOSE 1 */
 
 static int nfs_opendir(struct inode *, struct file *);
+static int nfs_closedir(struct inode *, struct file *);
 static int nfs_readdir(struct file *, void *, filldir_t);
 static struct dentry *nfs_lookup(struct inode *, struct dentry *, struct nameidata *);
 static int nfs_create(struct inode *, struct dentry *, int, struct nameidata *);
@@ -64,7 +65,7 @@ const struct file_operations nfs_dir_operations = {
         .read           = generic_read_dir,
         .readdir        = nfs_readdir,
         .open           = nfs_opendir,
-        .release        = nfs_release,
+        .release        = nfs_closedir,
         .fsync          = nfs_fsync_dir,
 };
 
@@ -133,13 +134,33 @@ const struct inode_operations nfs4_dir_inode_operations = {
 
 #endif /* CONFIG_NFS_V4 */
 
+static struct nfs_open_dir_context *alloc_nfs_open_dir_context(struct rpc_cred *cred)
+{
+        struct nfs_open_dir_context *ctx;
+        ctx = kmalloc(sizeof(*ctx), GFP_KERNEL);
+        if (ctx != NULL) {
+                ctx->dir_cookie = 0;
+                ctx->cred = get_rpccred(cred);
+        } else
+                ctx = ERR_PTR(-ENOMEM);
+        return ctx;
+}
+
+static void put_nfs_open_dir_context(struct nfs_open_dir_context *ctx)
+{
+        put_rpccred(ctx->cred);
+        kfree(ctx);
+}
+
 /*
  * Open file
  */
 static int
 nfs_opendir(struct inode *inode, struct file *filp)
 {
-        int res;
+        int res = 0;
+        struct nfs_open_dir_context *ctx;
+        struct rpc_cred *cred;
 
         dfprintk(FILE, "NFS: open dir(%s/%s)\n",
                         filp->f_path.dentry->d_parent->d_name.name,
@@ -147,8 +168,15 @@ nfs_opendir(struct inode *inode, struct file *filp)
 
         nfs_inc_stats(inode, NFSIOS_VFSOPEN);
 
-        /* Call generic open code in order to cache credentials */
-        res = nfs_open(inode, filp);
+        cred = rpc_lookup_cred();
+        if (IS_ERR(cred))
+                return PTR_ERR(cred);
+        ctx = alloc_nfs_open_dir_context(cred);
+        if (IS_ERR(ctx)) {
+                res = PTR_ERR(ctx);
+                goto out;
+        }
+        filp->private_data = ctx;
         if (filp->f_path.dentry == filp->f_path.mnt->mnt_root) {
                 /* This is a mountpoint, so d_revalidate will never
                  * have been called, so we need to refresh the
@@ -156,9 +184,18 @@ nfs_opendir(struct inode *inode, struct file *filp)
                  */
                 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
         }
+out:
+        put_rpccred(cred);
         return res;
 }
 
+static int
+nfs_closedir(struct inode *inode, struct file *filp)
+{
+        put_nfs_open_dir_context(filp->private_data);
+        return 0;
+}
+
 struct nfs_cache_array_entry {
         u64 cookie;
         u64 ino;
@@ -355,7 +392,8 @@ static
 int nfs_readdir_xdr_filler(struct page **pages, nfs_readdir_descriptor_t *desc,
                         struct nfs_entry *entry, struct file *file, struct inode *inode)
 {
-        struct rpc_cred *cred = nfs_file_cred(file);
+        struct nfs_open_dir_context *ctx = file->private_data;
+        struct rpc_cred *cred = ctx->cred;
         unsigned long   timestamp, gencount;
         int             error;
 
@@ -786,6 +824,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         struct inode    *inode = dentry->d_inode;
         nfs_readdir_descriptor_t my_desc,
                         *desc = &my_desc;
+        struct nfs_open_dir_context *dir_ctx = filp->private_data;
         int res;
 
         dfprintk(FILE, "NFS: readdir(%s/%s) starting at cookie %llu\n",
@@ -802,7 +841,7 @@ static int nfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
         memset(desc, 0, sizeof(*desc));
 
         desc->file = filp;
-        desc->dir_cookie = &nfs_file_open_context(filp)->dir_cookie;
+        desc->dir_cookie = &dir_ctx->dir_cookie;
         desc->decode = NFS_PROTO(inode)->decode_dirent;
         desc->plus = NFS_USE_READDIRPLUS(inode);
 
@@ -854,6 +893,7 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
 {
         struct dentry *dentry = filp->f_path.dentry;
         struct inode *inode = dentry->d_inode;
+        struct nfs_open_dir_context *dir_ctx = filp->private_data;
 
         dfprintk(FILE, "NFS: llseek dir(%s/%s, %lld, %d)\n",
                         dentry->d_parent->d_name.name,
@@ -873,7 +913,7 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int origin)
         }
         if (offset != filp->f_pos) {
                 filp->f_pos = offset;
-                nfs_file_open_context(filp)->dir_cookie = 0;
+                dir_ctx->dir_cookie = 0;
         }
 out:
         mutex_unlock(&inode->i_mutex);