1 files changed, 62 insertions, 144 deletions

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 8102391bb37..b5a0afc3ee1 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -7,6 +7,7 @@
  * NFS namespace
  */
 
+#include <linux/module.h>
 #include <linux/dcache.h>
 #include <linux/gfp.h>
 #include <linux/mount.h>
@@ -26,17 +27,13 @@ static LIST_HEAD(nfs_automount_list);
 static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
 int nfs_mountpoint_expiry_timeout = 500 * HZ;
 
-static struct vfsmount *nfs_do_submount(struct dentry *dentry,
-					struct nfs_fh *fh,
-					struct nfs_fattr *fattr,
-					rpc_authflavor_t authflavor);
-
 /*
  * nfs_path - reconstruct the path given an arbitrary dentry
  * @base - used to return pointer to the end of devname part of path
  * @dentry - pointer to dentry
  * @buffer - result buffer
  * @buflen - length of buffer
+ * @flags - options (see below)
  *
  * Helper function for constructing the server pathname
  * by arbitrary hashed dentry.
@@ -44,8 +41,14 @@ static struct vfsmount *nfs_do_submount(struct dentry *dentry,
  * This is mainly for use in figuring out the path on the
  * server side when automounting on top of an existing partition
  * and in generating /proc/mounts and friends.
+ *
+ * Supported flags:
+ * NFS_PATH_CANONICAL: ensure there is exactly one slash after
+ *		       the original device (export) name
+ *		       (if unset, the original name is returned verbatim)
  */
-char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen)
+char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen,
+	       unsigned flags)
 {
 	char *end;
 	int namelen;
@@ -78,7 +81,7 @@ rename_retry:
 		rcu_read_unlock();
 		goto rename_retry;
 	}
-	if (*end != '/') {
+	if ((flags & NFS_PATH_CANONICAL) && *end != '/') {
 		if (--buflen < 0) {
 			spin_unlock(&dentry->d_lock);
 			rcu_read_unlock();
@@ -95,9 +98,11 @@ rename_retry:
 		return end;
 	}
 	namelen = strlen(base);
-	/* Strip off excess slashes in base string */
-	while (namelen > 0 && base[namelen - 1] == '/')
-		namelen--;
+	if (flags & NFS_PATH_CANONICAL) {
+		/* Strip off excess slashes in base string */
+		while (namelen > 0 && base[namelen - 1] == '/')
+			namelen--;
+	}
 	buflen -= namelen;
 	if (buflen < 0) {
 		spin_unlock(&dentry->d_lock);
@@ -117,99 +122,7 @@ Elong_unlock:
 Elong:
 	return ERR_PTR(-ENAMETOOLONG);
 }
-
-#ifdef CONFIG_NFS_V4
-rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors)
-{
-	struct gss_api_mech *mech;
-	struct xdr_netobj oid;
-	int i;
-	rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX;
-
-	for (i = 0; i < flavors->num_flavors; i++) {
-		struct nfs4_secinfo_flavor *flavor;
-		flavor = &flavors->flavors[i];
-
-		if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) {
-			pseudoflavor = flavor->flavor;
-			break;
-		} else if (flavor->flavor == RPC_AUTH_GSS) {
-			oid.len  = flavor->gss.sec_oid4.len;
-			oid.data = flavor->gss.sec_oid4.data;
-			mech = gss_mech_get_by_OID(&oid);
-			if (!mech)
-				continue;
-			pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service);
-			gss_mech_put(mech);
-			break;
-		}
-	}
-
-	return pseudoflavor;
-}
-
-static int nfs_negotiate_security(const struct dentry *parent,
-				  const struct dentry *dentry,
-				  rpc_authflavor_t *flavor)
-{
-	struct page *page;
-	struct nfs4_secinfo_flavors *flavors;
-	int (*secinfo)(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
-	int ret = -EPERM;
-
-	secinfo = NFS_PROTO(parent->d_inode)->secinfo;
-	if (secinfo != NULL) {
-		page = alloc_page(GFP_KERNEL);
-		if (!page) {
-			ret = -ENOMEM;
-			goto out;
-		}
-		flavors = page_address(page);
-		ret = secinfo(parent->d_inode, &dentry->d_name, flavors);
-		*flavor = nfs_find_best_sec(flavors);
-		put_page(page);
-	}
-
-out:
-	return ret;
-}
-
-static int nfs_lookup_with_sec(struct nfs_server *server, struct dentry *parent,
-			       struct dentry *dentry, struct path *path,
-			       struct nfs_fh *fh, struct nfs_fattr *fattr,
-			       rpc_authflavor_t *flavor)
-{
-	struct rpc_clnt *clone;
-	struct rpc_auth *auth;
-	int err;
-
-	err = nfs_negotiate_security(parent, path->dentry, flavor);
-	if (err < 0)
-		goto out;
-	clone  = rpc_clone_client(server->client);
-	auth   = rpcauth_create(*flavor, clone);
-	if (!auth) {
-		err = -EIO;
-		goto out_shutdown;
-	}
-	err = server->nfs_client->rpc_ops->lookup(clone, parent->d_inode,
-						  &path->dentry->d_name,
-						  fh, fattr);
-out_shutdown:
-	rpc_shutdown_client(clone);
-out:
-	return err;
-}
-#else /* CONFIG_NFS_V4 */
-static inline int nfs_lookup_with_sec(struct nfs_server *server,
-				      struct dentry *parent, struct dentry *dentry,
-				      struct path *path, struct nfs_fh *fh,
-				      struct nfs_fattr *fattr,
-				      rpc_authflavor_t *flavor)
-{
-	return -EPERM;
-}
-#endif /* CONFIG_NFS_V4 */
+EXPORT_SYMBOL_GPL(nfs_path);
 
 /*
  * nfs_d_automount - Handle crossing a mountpoint on the server
@@ -227,11 +140,8 @@ struct vfsmount *nfs_d_automount(struct path *path)
 {
 	struct vfsmount *mnt;
 	struct nfs_server *server = NFS_SERVER(path->dentry->d_inode);
-	struct dentry *parent;
 	struct nfs_fh *fh = NULL;
 	struct nfs_fattr *fattr = NULL;
-	int err;
-	rpc_authflavor_t flavor = RPC_AUTH_UNIX;
 
 	dprintk("--> nfs_d_automount()\n");
 
@@ -247,23 +157,7 @@ struct vfsmount *nfs_d_automount(struct path *path)
 
 	dprintk("%s: enter\n", __func__);
 
-	/* Look it up again to get its attributes */
-	parent = dget_parent(path->dentry);
-	err = server->nfs_client->rpc_ops->lookup(server->client, parent->d_inode,
-						  &path->dentry->d_name,
-						  fh, fattr);
-	if (err == -EPERM && NFS_PROTO(parent->d_inode)->secinfo != NULL)
-		err = nfs_lookup_with_sec(server, parent, path->dentry, path, fh, fattr, &flavor);
-	dput(parent);
-	if (err != 0) {
-		mnt = ERR_PTR(err);
-		goto out;
-	}
-
-	if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
-		mnt = nfs_do_refmount(path->dentry);
-	else
-		mnt = nfs_do_submount(path->dentry, fh, fattr, flavor);
+	mnt = server->nfs_client->rpc_ops->submount(server, path->dentry, fh, fattr);
 	if (IS_ERR(mnt))
 		goto out;
 
@@ -276,15 +170,38 @@ out:
 	nfs_free_fattr(fattr);
 	nfs_free_fhandle(fh);
 out_nofree:
-	dprintk("<-- nfs_follow_mountpoint() = %p\n", mnt);
+	if (IS_ERR(mnt))
+		dprintk("<-- %s(): error %ld\n", __func__, PTR_ERR(mnt));
+	else
+		dprintk("<-- %s() = %p\n", __func__, mnt);
 	return mnt;
 }
 
+static int
+nfs_namespace_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
+{
+	if (NFS_FH(dentry->d_inode)->size != 0)
+		return nfs_getattr(mnt, dentry, stat);
+	generic_fillattr(dentry->d_inode, stat);
+	return 0;
+}
+
+static int
+nfs_namespace_setattr(struct dentry *dentry, struct iattr *attr)
+{
+	if (NFS_FH(dentry->d_inode)->size != 0)
+		return nfs_setattr(dentry, attr);
+	return -EACCES;
+}
+
 const struct inode_operations nfs_mountpoint_inode_operations = {
 	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
 };
 
 const struct inode_operations nfs_referral_inode_operations = {
+	.getattr	= nfs_namespace_getattr,
+	.setattr	= nfs_namespace_setattr,
 };
 
 static void nfs_expire_automounts(struct work_struct *work)
@@ -309,20 +226,7 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
 					   const char *devname,
 					   struct nfs_clone_mount *mountdata)
 {
-#ifdef CONFIG_NFS_V4
-	struct vfsmount *mnt = ERR_PTR(-EINVAL);
-	switch (server->nfs_client->rpc_ops->version) {
-		case 2:
-		case 3:
-			mnt = vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
-			break;
-		case 4:
-			mnt = vfs_kern_mount(&nfs4_xdev_fs_type, 0, devname, mountdata);
-	}
-	return mnt;
-#else
 	return vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
-#endif
 }
 
 /**
@@ -333,10 +237,8 @@ static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
  * @authflavor - security flavor to use when performing the mount
  *
  */
-static struct vfsmount *nfs_do_submount(struct dentry *dentry,
-					struct nfs_fh *fh,
-					struct nfs_fattr *fattr,
-					rpc_authflavor_t authflavor)
+struct vfsmount *nfs_do_submount(struct dentry *dentry, struct nfs_fh *fh,
+				 struct nfs_fattr *fattr, rpc_authflavor_t authflavor)
 {
 	struct nfs_clone_mount mountdata = {
 		.sb = dentry->d_sb,
@@ -351,9 +253,8 @@ static struct vfsmount *nfs_do_submount(struct dentry *dentry,
 
 	dprintk("--> nfs_do_submount()\n");
 
-	dprintk("%s: submounting on %s/%s\n", __func__,
-			dentry->d_parent->d_name.name,
-			dentry->d_name.name);
+	dprintk("%s: submounting on %pd2\n", __func__,
+			dentry);
 	if (page == NULL)
 		goto out;
 	devname = nfs_devname(dentry, page, PAGE_SIZE);
@@ -369,3 +270,20 @@ out:
 	dprintk("<-- nfs_do_submount() = %p\n", mnt);
 	return mnt;
 }
+EXPORT_SYMBOL_GPL(nfs_do_submount);
+
+struct vfsmount *nfs_submount(struct nfs_server *server, struct dentry *dentry,
+			      struct nfs_fh *fh, struct nfs_fattr *fattr)
+{
+	int err;
+	struct dentry *parent = dget_parent(dentry);
+
+	/* Look it up again to get its attributes */
+	err = server->nfs_client->rpc_ops->lookup(parent->d_inode, &dentry->d_name, fh, fattr, NULL);
+	dput(parent);
+	if (err != 0)
+		return ERR_PTR(err);
+
+	return nfs_do_submount(dentry, fh, fattr, server->client->cl_auth->au_flavor);
+}
+EXPORT_SYMBOL_GPL(nfs_submount);