1 files changed, 72 insertions, 56 deletions

diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c
index db86006956b0..1e6f556514d6 100644
--- a/fs/exportfs/expfs.c
+++ b/fs/exportfs/expfs.c
@@ -6,11 +6,36 @@
 #include <linux/mount.h>
 #include <linux/namei.h>
 
-struct export_operations export_op_default;
+#define dprintk(fmt, args...) do{}while(0)
 
-#define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun)
 
-#define dprintk(fmt, args...) do{}while(0)
+static int get_name(struct dentry *dentry, char *name,
+                struct dentry *child);
+
+
+static struct dentry *exportfs_get_dentry(struct super_block *sb, void *obj)
+{
+        struct dentry *result = ERR_PTR(-ESTALE);
+
+        if (sb->s_export_op->get_dentry) {
+                result = sb->s_export_op->get_dentry(sb, obj);
+                if (!result)
+                        result = ERR_PTR(-ESTALE);
+        }
+
+        return result;
+}
+
+static int exportfs_get_name(struct dentry *dir, char *name,
+                struct dentry *child)
+{
+        struct export_operations *nop = dir->d_sb->s_export_op;
+
+        if (nop->get_name)
+                return nop->get_name(dir, name, child);
+        else
+                return get_name(dir, name, child);
+}
 
 static struct dentry *
 find_acceptable_alias(struct dentry *result,
@@ -78,7 +103,7 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
 {
         struct dentry *result = NULL;
         struct dentry *target_dir;
-        int err;
+        int err = -ESTALE;
         struct export_operations *nops = sb->s_export_op;
         struct dentry *alias;
         int noprogress;
@@ -87,14 +112,10 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
         /*
          * Attempt to find the inode.
          */
-        result = CALL(sb->s_export_op,get_dentry)(sb,obj);
-        err = -ESTALE;
-        if (result == NULL)
-                goto err_out;
-        if (IS_ERR(result)) {
-                err = PTR_ERR(result);
-                goto err_out;
-        }
+        result = exportfs_get_dentry(sb, obj);
+        if (IS_ERR(result))
+                return result;
+
         if (S_ISDIR(result->d_inode->i_mode) &&
             (result->d_flags & DCACHE_DISCONNECTED)) {
                 /* it is an unconnected directory, we must connect it */
@@ -122,11 +143,11 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
                 if (parent == NULL)
                         goto err_result;
 
-                target_dir = CALL(sb->s_export_op,get_dentry)(sb,parent);
-                if (IS_ERR(target_dir))
+                target_dir = exportfs_get_dentry(sb,parent);
+                if (IS_ERR(target_dir)) {
                         err = PTR_ERR(target_dir);
-                if (target_dir == NULL || IS_ERR(target_dir))
                         goto err_result;
+                }
         }
         /*
          * Now we need to make sure that target_dir is properly connected.
@@ -177,18 +198,27 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
                         spin_unlock(&pd->d_lock);
                         noprogress = 0;
                 } else {
-                        /* we have hit the top of a disconnected path.  Try
-                         * to find parent and connect
-                         * note: racing with some other process renaming a
-                         * directory isn't much of a problem here.  If someone
-                         * renames the directory, it will end up properly
-                         * connected, which is what we want
+                        /*
+                         * We have hit the top of a disconnected path, try to
+                         * find parent and connect.
+                         *
+                         * Racing with some other process renaming a directory
+                         * isn't much of a problem here.  If someone renames
+                         * the directory, it will end up properly connected,
+                         * which is what we want
+                         *
+                         * Getting the parent can't be supported generically,
+                         * the locking is too icky.
+                         *
+                         * Instead we just return EACCES.  If server reboots
+                         * or inodes get flushed, you lose
                          */
-                        struct dentry *ppd;
+                        struct dentry *ppd = ERR_PTR(-EACCES);
                         struct dentry *npd;
 
                         mutex_lock(&pd->d_inode->i_mutex);
-                        ppd = CALL(nops,get_parent)(pd);
+                        if (nops->get_parent)
+                                ppd = nops->get_parent(pd);
                         mutex_unlock(&pd->d_inode->i_mutex);
 
                         if (IS_ERR(ppd)) {
@@ -199,7 +229,7 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
                                 break;
                         }
                         dprintk("find_exported_dentry: find name of %lu in %lu\n", pd->d_inode->i_ino, ppd->d_inode->i_ino);
-                        err = CALL(nops,get_name)(ppd, nbuf, pd);
+                        err = exportfs_get_name(ppd, nbuf, pd);
                         if (err) {
                                 dput(ppd);
                                 dput(pd);
@@ -250,7 +280,7 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
         /* if we weren't after a directory, have one more step to go */
         if (result != target_dir) {
                 struct dentry *nresult;
-                err = CALL(nops,get_name)(target_dir, nbuf, result);
+                err = exportfs_get_name(target_dir, nbuf, result);
                 if (!err) {
                         mutex_lock(&target_dir->d_inode->i_mutex);
                         nresult = lookup_one_len(nbuf, target_dir, strlen(nbuf));
@@ -286,23 +316,9 @@ find_exported_dentry(struct super_block *sb, void *obj, void *parent,
         dput(target_dir);
  err_result:
         dput(result);
- err_out:
         return ERR_PTR(err);
 }
 
-
-
-static struct dentry *get_parent(struct dentry *child)
-{
-        /* get_parent cannot be supported generically, the locking
-         * is too icky.
-         * instead, we just return EACCES.  If server reboots or inodes
-         * get flushed, you lose
-         */
-        return ERR_PTR(-EACCES);
-}
-
-
 struct getdents_callback {
         char *name;             /* name that was found. It already points to a
                                    buffer NAME_MAX+1 is size */
@@ -392,11 +408,6 @@ out:
         return error;
 }
 
-static struct dentry *get_dentry(struct super_block *sb, void *vobjp)
-{
-        return ERR_PTR(-ESTALE);
-}
-
 /**
  * export_encode_fh - default export_operations->encode_fh function
  * @dentry:  the dentry to encode
@@ -472,9 +483,15 @@ static struct dentry *export_decode_fh(struct super_block *sb, __u32 *fh, int fh
 int exportfs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
                 int connectable)
 {
-        struct export_operations *nop = dentry->d_sb->s_export_op;
+        struct export_operations *nop = dentry->d_sb->s_export_op;
+        int error;
 
-        return CALL(nop, encode_fh)(dentry, fh, max_len, connectable);
+        if (nop->encode_fh)
+                error = nop->encode_fh(dentry, fh, max_len, connectable);
+        else
+                error = export_encode_fh(dentry, fh, max_len, connectable);
+
+        return error;
 }
 EXPORT_SYMBOL_GPL(exportfs_encode_fh);
 
@@ -483,21 +500,20 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, __u32 *fh, int fh_len,
                 void *context)
 {
         struct export_operations *nop = mnt->mnt_sb->s_export_op;
+        struct dentry *result;
 
-        return CALL(nop, decode_fh)(mnt->mnt_sb, fh, fh_len, fileid_type,
+        if (nop->decode_fh) {
+                result = nop->decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
                         acceptable, context);
+        } else {
+                result = export_decode_fh(mnt->mnt_sb, fh, fh_len, fileid_type,
+                        acceptable, context);
+        }
+
+        return result;
 }
 EXPORT_SYMBOL_GPL(exportfs_decode_fh);
 
-struct export_operations export_op_default = {
-        .decode_fh      = export_decode_fh,
-        .encode_fh      = export_encode_fh,
-
-        .get_name       = get_name,
-        .get_parent     = get_parent,
-        .get_dentry     = get_dentry,
-};
-
 EXPORT_SYMBOL(find_exported_dentry);
 
 MODULE_LICENSE("GPL");