static int nilfs_get_root_dentry(struct super_block *sb,
struct nilfs_root *root,
struct dentry **root_dentry)
{
struct inode *inode;
struct dentry *dentry;
int ret = 0;
inode = nilfs_iget(sb, root, NILFS_ROOT_INO);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
nilfs_msg(sb, KERN_ERR, "error %d getting root inode", ret);
goto out;
}
if (!S_ISDIR(inode->i_mode) || !inode->i_blocks || !inode->i_size) {
iput(inode);
nilfs_msg(sb, KERN_ERR, "corrupt root inode");
ret = -EINVAL;
goto out;
}
if (root->cno == NILFS_CPTREE_CURRENT_CNO) {
dentry = d_find_alias(inode);
if (!dentry) {
dentry = d_make_root(inode);
if (!dentry) {
ret = -ENOMEM;
goto failed_dentry;
}
} else {
iput(inode);
}
} else {
dentry = d_obtain_root(inode);
if (IS_ERR(dentry)) {
ret = PTR_ERR(dentry);
goto failed_dentry;
}
}
*root_dentry = dentry;
out:
return ret;
failed_dentry:
nilfs_msg(sb, KERN_ERR, "error %d getting root dentry", ret);
goto out;
}
/*
* get an NFS2/NFS3 root dentry from the root filehandle
*/
struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh,
const char *devname)
{
struct nfs_server *server = NFS_SB(sb);
struct nfs_fsinfo fsinfo;
struct dentry *ret;
struct inode *inode;
void *name = kstrdup(devname, GFP_KERNEL);
int error;
if (!name)
return ERR_PTR(-ENOMEM);
/* get the actual root for this mount */
fsinfo.fattr = nfs_alloc_fattr();
if (fsinfo.fattr == NULL) {
kfree(name);
return ERR_PTR(-ENOMEM);
}
error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
if (error < 0) {
dprintk("nfs_get_root: getattr error = %d\n", -error);
ret = ERR_PTR(error);
goto out;
}
inode = nfs_fhget(sb, mntfh, fsinfo.fattr, NULL);
if (IS_ERR(inode)) {
dprintk("nfs_get_root: get root inode failed\n");
ret = ERR_CAST(inode);
goto out;
}
error = nfs_superblock_set_dummy_root(sb, inode);
if (error != 0) {
ret = ERR_PTR(error);
goto out;
}
/* root dentries normally start off anonymous and get spliced in later
* if the dentry tree reaches them; however if the dentry already
* exists, we'll pick it up at this point and use it as the root
*/
ret = d_obtain_root(inode);
if (IS_ERR(ret)) {
dprintk("nfs_get_root: get root dentry failed\n");
goto out;
}
security_d_instantiate(ret, inode);
spin_lock(&ret->d_lock);
if (IS_ROOT(ret) && !ret->d_fsdata &&
!(ret->d_flags & DCACHE_NFSFS_RENAMED)) {
ret->d_fsdata = name;
name = NULL;
}
spin_unlock(&ret->d_lock);
out:
kfree(name);
nfs_free_fattr(fsinfo.fattr);
return ret;
}
