Wrapfs: use d_alloc_root

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c
index 35bccc818971d2d8d4644905e9f43df1701d9c7b..041d674279a411789f4c016dba4231efc07d0d7f 100644 (file)
--- a/fs/unionfs/lookup.c
+++ b/fs/unionfs/lookup.c
@@ -30,7 +30,7 @@ struct dentry *__lookup_one(struct dentry *base, struct vfsmount *mnt,
                            const char *name, struct vfsmount **new_mnt)
 {
        struct dentry *dentry = NULL;
-       struct path lower_path;
+       struct path lower_path = {NULL, NULL};
        int err;
 
        /* we use flags=0 to get basic lookup */

diff --git a/fs/unionfs/main.c b/fs/unionfs/main.c
index f4bcd89498612644651d46f9966657dcee14dfda..87cd1fcdfe1193da0235b770bdc948f25d468df5 100644 (file)
--- a/fs/unionfs/main.c
+++ b/fs/unionfs/main.c
@@ -525,32 +525,6 @@ out:
        return lower_root_info;
 }
 
-/*
- * our custom d_alloc_root work-alike
- *
- * we can't use d_alloc_root if we want to use our own interpose function
- * unchanged, so we simply call our own "fake" d_alloc_root
- */
-static struct dentry *unionfs_d_alloc_root(struct super_block *sb)
-{
-       struct dentry *ret = NULL;
-
-       if (sb) {
-               static const struct qstr name = {
-                       .name = "/",
-                       .len = 1
-               };
-
-               ret = d_alloc(NULL, &name);
-               if (likely(ret)) {
-                       d_set_d_op(ret, &unionfs_dops);
-                       ret->d_sb = sb;
-                       ret->d_parent = ret;
-               }
-       }
-       return ret;
-}
-
 /*
  * There is no need to lock the unionfs_super_info's rwsem as there is no
  * way anyone can have a reference to the superblock at this point in time.
@@ -561,6 +535,7 @@ static int unionfs_read_super(struct super_block *sb, void *raw_data,
        int err = 0;
        struct unionfs_dentry_info *lower_root_info = NULL;
        int bindex, bstart, bend;
+       struct inode *inode = NULL;
 
        if (!raw_data) {
                printk(KERN_ERR
@@ -618,12 +593,18 @@ static int unionfs_read_super(struct super_block *sb, void *raw_data,
 
        sb->s_op = &unionfs_sops;
 
-       /* See comment next to the definition of unionfs_d_alloc_root */
-       sb->s_root = unionfs_d_alloc_root(sb);
+       /* get a new inode and allocate our root dentry */
+       inode = unionfs_iget(sb, iunique(sb, UNIONFS_ROOT_INO));
+       if (IS_ERR(inode)) {
+               err = PTR_ERR(inode);
+               goto out_dput;
+       }
+       sb->s_root = d_alloc_root(inode);
        if (unlikely(!sb->s_root)) {
                err = -ENOMEM;
-               goto out_dput;
+               goto out_iput;
        }
+       d_set_d_op(sb->s_root, &unionfs_dops);
 
        /* link the upper and lower dentries */
        sb->s_root->d_fsdata = NULL;
@@ -631,6 +612,8 @@ static int unionfs_read_super(struct super_block *sb, void *raw_data,
        if (unlikely(err))
                goto out_freedpd;
 
+       /* if get here: cannot have error */
+
        /* Set the lower dentries for s_root */
        for (bindex = bstart; bindex <= bend; bindex++) {
                struct dentry *d;
@@ -648,15 +631,18 @@ static int unionfs_read_super(struct super_block *sb, void *raw_data,
        /* Set the generation number to one, since this is for the mount. */
        atomic_set(&UNIONFS_D(sb->s_root)->generation, 1);
 
+       if (atomic_read(&inode->i_count) <= 1)
+               unionfs_fill_inode(sb->s_root, inode);
+
        /*
-        * Call interpose to create the upper level inode.  Only
-        * INTERPOSE_LOOKUP can return a value other than 0 on err.
+        * No need to call interpose because we already have a positive
+        * dentry, which was instantiated by d_alloc_root.  Just need to
+        * d_rehash it.
         */
-       err = PTR_ERR(unionfs_interpose(sb->s_root, sb, 0));
+       d_rehash(sb->s_root);
+
        unionfs_unlock_dentry(sb->s_root);
-       if (!err)
-               goto out;
-       /* else fall through */
+       goto out; /* all is well */
 
 out_freedpd:
        if (UNIONFS_D(sb->s_root)) {
@@ -665,6 +651,9 @@ out_freedpd:
        }
        dput(sb->s_root);
 
+out_iput:
+       iput(inode);
+
 out_dput:
        if (lower_root_info && !IS_ERR(lower_root_info)) {
                for (bindex = lower_root_info->bstart;