1 files changed, 62 insertions, 239 deletions

diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 20c6f39ea38..b94f80420a5 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -23,288 +23,111 @@
 #include <linux/sunrpc/stats.h>
 #include <linux/nfs_fs.h>
 #include <linux/nfs_mount.h>
-#include <linux/nfs4_mount.h>
 #include <linux/lockd/bind.h>
-#include <linux/smp_lock.h>
 #include <linux/seq_file.h>
 #include <linux/mount.h>
-#include <linux/nfs_idmap.h>
 #include <linux/vfs.h>
 #include <linux/namei.h>
-#include <linux/namespace.h>
 #include <linux/security.h>
 
-#include <asm/system.h>
 #include <asm/uaccess.h>
 
-#include "nfs4_fs.h"
-#include "delegation.h"
 #include "internal.h"
 
 #define NFSDBG_FACILITY		NFSDBG_CLIENT
-#define NFS_PARANOIA 1
 
 /*
- * get an NFS2/NFS3 root dentry from the root filehandle
- */
-struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
-{
-	struct nfs_server *server = NFS_SB(sb);
-	struct nfs_fsinfo fsinfo;
-	struct nfs_fattr fattr;
-	struct dentry *mntroot;
-	struct inode *inode;
-	int error;
-
-	/* create a dummy root dentry with dummy inode for this superblock */
-	if (!sb->s_root) {
-		struct nfs_fh dummyfh;
-		struct dentry *root;
-		struct inode *iroot;
-
-		memset(&dummyfh, 0, sizeof(dummyfh));
-		memset(&fattr, 0, sizeof(fattr));
-		nfs_fattr_init(&fattr);
-		fattr.valid = NFS_ATTR_FATTR;
-		fattr.type = NFDIR;
-		fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR;
-		fattr.nlink = 2;
-
-		iroot = nfs_fhget(sb, &dummyfh, &fattr);
-		if (IS_ERR(iroot))
-			return ERR_PTR(PTR_ERR(iroot));
-
-		root = d_alloc_root(iroot);
-		if (!root) {
-			iput(iroot);
-			return ERR_PTR(-ENOMEM);
-		}
-
-		sb->s_root = root;
-	}
-
-	/* get the actual root for this mount */
-	fsinfo.fattr = &fattr;
-
-	error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
-	if (error < 0) {
-		dprintk("nfs_get_root: getattr error = %d\n", -error);
-		return ERR_PTR(error);
-	}
-
-	inode = nfs_fhget(sb, mntfh, fsinfo.fattr);
-	if (IS_ERR(inode)) {
-		dprintk("nfs_get_root: get root inode failed\n");
-		return ERR_PTR(PTR_ERR(inode));
-	}
-
-	/* 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
-	 */
-	mntroot = d_alloc_anon(inode);
-	if (!mntroot) {
-		iput(inode);
-		dprintk("nfs_get_root: get root dentry failed\n");
-		return ERR_PTR(-ENOMEM);
-	}
-
-	security_d_instantiate(mntroot, inode);
-
-	if (!mntroot->d_op)
-		mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
-
-	return mntroot;
-}
-
-#ifdef CONFIG_NFS_V4
-
-/*
- * Do a simple pathwalk from the root FH of the server to the nominated target
- * of the mountpoint
- * - give error on symlinks
- * - give error on ".." occurring in the path
- * - follow traversals
+ * Set the superblock root dentry.
+ * Note that this function frees the inode in case of error.
  */
-int nfs4_path_walk(struct nfs_server *server,
-		   struct nfs_fh *mntfh,
-		   const char *path)
+static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *inode)
 {
-	struct nfs_fsinfo fsinfo;
-	struct nfs_fattr fattr;
-	struct nfs_fh lastfh;
-	struct qstr name;
-	int ret;
-	//int referral_count = 0;
-
-	dprintk("--> nfs4_path_walk(,,%s)\n", path);
-
-	fsinfo.fattr = &fattr;
-	nfs_fattr_init(&fattr);
-
-	if (*path++ != '/') {
-		dprintk("nfs4_get_root: Path does not begin with a slash\n");
-		return -EINVAL;
-	}
-
-	/* Start by getting the root filehandle from the server */
-	ret = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
-	if (ret < 0) {
-		dprintk("nfs4_get_root: getroot error = %d\n", -ret);
-		return ret;
-	}
-
-	if (fattr.type != NFDIR) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " getroot encountered non-directory\n");
-		return -ENOTDIR;
-	}
-
-	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " getroot obtained referral\n");
-		return -EREMOTE;
-	}
-
-next_component:
-	dprintk("Next: %s\n", path);
-
-	/* extract the next bit of the path */
-	if (!*path)
-		goto path_walk_complete;
-
-	name.name = path;
-	while (*path && *path != '/')
-		path++;
-	name.len = path - (const char *) name.name;
-
-eat_dot_dir:
-	while (*path == '/')
-		path++;
-
-	if (path[0] == '.' && (path[1] == '/' || !path[1])) {
-		path += 2;
-		goto eat_dot_dir;
+	/* The mntroot acts as the dummy root dentry for this superblock */
+	if (sb->s_root == NULL) {
+		sb->s_root = d_make_root(inode);
+		if (sb->s_root == NULL)
+			return -ENOMEM;
+		ihold(inode);
+		/*
+		 * Ensure that this dentry is invisible to d_find_alias().
+		 * Otherwise, it may be spliced into the tree by
+		 * d_materialise_unique if a parent directory from the same
+		 * filesystem gets mounted at a later time.
+		 * This again causes shrink_dcache_for_umount_subtree() to
+		 * Oops, since the test for IS_ROOT() will fail.
+		 */
+		spin_lock(&sb->s_root->d_inode->i_lock);
+		spin_lock(&sb->s_root->d_lock);
+		hlist_del_init(&sb->s_root->d_alias);
+		spin_unlock(&sb->s_root->d_lock);
+		spin_unlock(&sb->s_root->d_inode->i_lock);
 	}
-
-	if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || !path[2])
-	    ) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " Mount path contains reference to \"..\"\n");
-		return -EINVAL;
-	}
-
-	/* lookup the next FH in the sequence */
-	memcpy(&lastfh, mntfh, sizeof(lastfh));
-
-	dprintk("LookupFH: %*.*s [%s]\n", name.len, name.len, name.name, path);
-
-	ret = server->nfs_client->rpc_ops->lookupfh(server, &lastfh, &name,
-						    mntfh, &fattr);
-	if (ret < 0) {
-		dprintk("nfs4_get_root: getroot error = %d\n", -ret);
-		return ret;
-	}
-
-	if (fattr.type != NFDIR) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " lookupfh encountered non-directory\n");
-		return -ENOTDIR;
-	}
-
-	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
-		printk(KERN_ERR "nfs4_get_root:"
-		       " lookupfh obtained referral\n");
-		return -EREMOTE;
-	}
-
-	goto next_component;
-
-path_walk_complete:
-	memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
-	dprintk("<-- nfs4_path_walk() = 0\n");
 	return 0;
 }
 
 /*
- * get an NFS4 root dentry from the root filehandle
+ * get an NFS2/NFS3 root dentry from the root filehandle
  */
-struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
+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_fattr fattr;
-	struct dentry *mntroot;
+	struct nfs_fsinfo fsinfo;
+	struct dentry *ret;
 	struct inode *inode;
+	void *name = kstrdup(devname, GFP_KERNEL);
 	int error;
 
-	dprintk("--> nfs4_get_root()\n");
-
-	/* create a dummy root dentry with dummy inode for this superblock */
-	if (!sb->s_root) {
-		struct nfs_fh dummyfh;
-		struct dentry *root;
-		struct inode *iroot;
-
-		memset(&dummyfh, 0, sizeof(dummyfh));
-		memset(&fattr, 0, sizeof(fattr));
-		nfs_fattr_init(&fattr);
-		fattr.valid = NFS_ATTR_FATTR;
-		fattr.type = NFDIR;
-		fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR;
-		fattr.nlink = 2;
-
-		iroot = nfs_fhget(sb, &dummyfh, &fattr);
-		if (IS_ERR(iroot))
-			return ERR_PTR(PTR_ERR(iroot));
-
-		root = d_alloc_root(iroot);
-		if (!root) {
-			iput(iroot);
-			return ERR_PTR(-ENOMEM);
-		}
-
-		sb->s_root = root;
-	}
+	if (!name)
+		return ERR_PTR(-ENOMEM);
 
-	/* get the info about the server and filesystem */
-	error = nfs4_server_capabilities(server, mntfh);
-	if (error < 0) {
-		dprintk("nfs_get_root: getcaps error = %d\n",
-			-error);
-		return ERR_PTR(error);
+	/* get the actual root for this mount */
+	fsinfo.fattr = nfs_alloc_fattr();
+	if (fsinfo.fattr == NULL) {
+		kfree(name);
+		return ERR_PTR(-ENOMEM);
 	}
 
-	/* get the actual root for this mount */
-	error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr);
+	error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
 	if (error < 0) {
 		dprintk("nfs_get_root: getattr error = %d\n", -error);
-		return ERR_PTR(error);
+		ret = ERR_PTR(error);
+		goto out;
 	}
 
-	inode = nfs_fhget(sb, mntfh, &fattr);
+	inode = nfs_fhget(sb, mntfh, fsinfo.fattr, NULL);
 	if (IS_ERR(inode)) {
 		dprintk("nfs_get_root: get root inode failed\n");
-		return ERR_PTR(PTR_ERR(inode));
+		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
 	 */
-	mntroot = d_alloc_anon(inode);
-	if (!mntroot) {
-		iput(inode);
+	ret = d_obtain_alias(inode);
+	if (IS_ERR(ret)) {
 		dprintk("nfs_get_root: get root dentry failed\n");
-		return ERR_PTR(-ENOMEM);
+		goto out;
 	}
 
-	security_d_instantiate(mntroot, inode);
-
-	if (!mntroot->d_op)
-		mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
-
-	dprintk("<-- nfs4_get_root()\n");
-	return mntroot;
+	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;
 }
-
-#endif /* CONFIG_NFS_V4 */