#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/mnt_namespace.h>
#include <linux/security.h>
#include <asm/system.h>
#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);
+ /*
+ * 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(&dcache_lock);
+ list_del_init(&sb->s_root->d_alias);
+ spin_unlock(&dcache_lock);
+ }
+ return 0;
+}
/*
* get an NFS2/NFS3 root dentry from the root filehandle
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;
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));
+ return ERR_CAST(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
*/
- mntroot = d_alloc_anon(inode);
- if (!mntroot) {
- iput(inode);
+ mntroot = d_obtain_alias(inode);
+ if (IS_ERR(mntroot)) {
dprintk("nfs_get_root: get root dentry failed\n");
- return ERR_PTR(-ENOMEM);
+ return mntroot;
}
security_d_instantiate(mntroot, inode);
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);
return ret;
}
- if (fattr.type != NFDIR) {
+ if (!S_ISDIR(fattr.mode)) {
printk(KERN_ERR "nfs4_get_root:"
" getroot encountered non-directory\n");
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");
path++;
name.len = path - (const char *) name.name;
+ if (name.len > NFS4_MAXNAMLEN)
+ return -ENAMETOOLONG;
+
eat_dot_dir:
while (*path == '/')
path++;
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:"
return ret;
}
- if (fattr.type != NFDIR) {
+ if (!S_ISDIR(fattr.mode)) {
printk(KERN_ERR "nfs4_get_root:"
" lookupfh encountered non-directory\n");
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");
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) {
inode = nfs_fhget(sb, mntfh, &fattr);
if (IS_ERR(inode)) {
dprintk("nfs_get_root: get root inode failed\n");
- return ERR_PTR(PTR_ERR(inode));
+ return ERR_CAST(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
*/
- mntroot = d_alloc_anon(inode);
- if (!mntroot) {
- iput(inode);
+ mntroot = d_obtain_alias(inode);
+ if (IS_ERR(mntroot)) {
dprintk("nfs_get_root: get root dentry failed\n");
- return ERR_PTR(-ENOMEM);
+ return mntroot;
}
security_d_instantiate(mntroot, inode);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff