X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fnfs%2Fgetroot.c;h=0ee43843f4ec40c79f1516fb869a5eb720cb355c;hb=c2319540cd7330fa9066e5b9b84d357a2c8631a2;hp=8391bd7a83ce46b81b9480f6710e7cbe37512ae3;hpb=e7b3ca08549caccf5d6e1cf066780bf4f0ae77a7;p=linux-2.6

diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
index 8391bd7a83..0ee43843f4 100644
--- a/fs/nfs/getroot.c
+++ b/fs/nfs/getroot.c
@@ -25,7 +25,6 @@
 #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>
@@ -42,7 +41,25 @@
 #include "internal.h"
 
 #define NFSDBG_FACILITY		NFSDBG_CLIENT
-#define NFS_PARANOIA 1
+
+/*
+ * Set the superblock root dentry.
+ * Note that this function frees the inode in case of error.
+ */
+static int nfs_superblock_set_dummy_root(struct super_block *sb, struct inode *inode)
+{
+	/* The mntroot acts as the dummy root dentry for this superblock */
+	if (sb->s_root == NULL) {
+		sb->s_root = d_alloc_root(inode);
+		if (sb->s_root == NULL) {
+			iput(inode);
+			return -ENOMEM;
+		}
+		/* Circumvent igrab(): we know the inode is not being freed */
+		atomic_inc(&inode->i_count);
+	}
+	return 0;
+}
 
 /*
  * get an NFS2/NFS3 root dentry from the root filehandle
@@ -56,33 +73,6 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 	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;
 
@@ -98,6 +88,10 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 		return ERR_PTR(PTR_ERR(inode));
 	}
 
+	error = nfs_superblock_set_dummy_root(sb, inode);
+	if (error != 0)
+		return ERR_PTR(error);
+
 	/* 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
@@ -135,17 +129,15 @@ int nfs4_path_walk(struct nfs_server *server,
 	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;
-	}
+	/* Eat leading slashes */
+	while (*path == '/')
+		path++;
 
 	/* Start by getting the root filehandle from the server */
 	ret = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo);
@@ -160,6 +152,7 @@ int nfs4_path_walk(struct nfs_server *server,
 		return -ENOTDIR;
 	}
 
+	/* FIXME: It is quite valid for the server to return a referral here */
 	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
 		printk(KERN_ERR "nfs4_get_root:"
 		       " getroot obtained referral\n");
@@ -178,6 +171,9 @@ next_component:
 		path++;
 	name.len = path - (const char *) name.name;
 
+	if (name.len > NFS4_MAXNAMLEN)
+		return -ENAMETOOLONG;
+
 eat_dot_dir:
 	while (*path == '/')
 		path++;
@@ -187,6 +183,7 @@ eat_dot_dir:
 		goto eat_dot_dir;
 	}
 
+	/* FIXME: Why shouldn't the user be able to use ".." in the path? */
 	if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || !path[2])
 	    ) {
 		printk(KERN_ERR "nfs4_get_root:"
@@ -212,6 +209,7 @@ eat_dot_dir:
 		return -ENOTDIR;
 	}
 
+	/* FIXME: Referrals are quite valid here too */
 	if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) {
 		printk(KERN_ERR "nfs4_get_root:"
 		       " lookupfh obtained referral\n");
@@ -239,33 +237,6 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 
 	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;
-	}
-
 	/* get the info about the server and filesystem */
 	error = nfs4_server_capabilities(server, mntfh);
 	if (error < 0) {
@@ -287,6 +258,10 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
 		return ERR_PTR(PTR_ERR(inode));
 	}
 
+	error = nfs_superblock_set_dummy_root(sb, inode);
+	if (error != 0)
+		return ERR_PTR(error);
+
 	/* 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