#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>
#define NFSDBG_FACILITY NFSDBG_CLIENT
/*
+ * 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 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 dentry *ret;
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;
+ fsinfo.fattr = nfs_alloc_fattr();
+ if (fsinfo.fattr == NULL)
+ 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);
- return ERR_PTR(error);
+ ret = ERR_PTR(error);
+ goto out;
}
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));
+ 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;
+ security_d_instantiate(ret, inode);
- return mntroot;
+ if (ret->d_op == NULL)
+ ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+out:
+ nfs_free_fattr(fsinfo.fattr);
+ return ret;
}
#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
- */
-int nfs4_path_walk(struct nfs_server *server,
- struct nfs_fh *mntfh,
- const char *path)
+int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh)
{
struct nfs_fsinfo fsinfo;
- struct nfs_fattr fattr;
- struct nfs_fh lastfh;
- struct qstr name;
- int ret;
-
- dprintk("--> nfs4_path_walk(,,%s)\n", path);
+ int ret = -ENOMEM;
- fsinfo.fattr = &fattr;
- nfs_fattr_init(&fattr);
+ dprintk("--> nfs4_get_rootfh()\n");
- /* Eat leading slashes */
- while (*path == '/')
- path++;
+ fsinfo.fattr = nfs_alloc_fattr();
+ if (fsinfo.fattr == NULL)
+ goto out;
/* 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;
+ dprintk("nfs4_get_rootfh: getroot error = %d\n", -ret);
+ goto out;
}
- if (fattr.type != NFDIR) {
- printk(KERN_ERR "nfs4_get_root:"
+ if (!(fsinfo.fattr->valid & NFS_ATTR_FATTR_MODE)
+ || !S_ISDIR(fsinfo.fattr->mode)) {
+ printk(KERN_ERR "nfs4_get_rootfh:"
" getroot encountered non-directory\n");
- return -ENOTDIR;
+ ret = -ENOTDIR;
+ goto out;
}
- /* 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:"
+ if (fsinfo.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
+ printk(KERN_ERR "nfs4_get_rootfh:"
" 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;
-
- if (name.len > NFS4_MAXNAMLEN)
- return -ENAMETOOLONG;
-
-eat_dot_dir:
- while (*path == '/')
- path++;
-
- if (path[0] == '.' && (path[1] == '/' || !path[1])) {
- path += 2;
- goto eat_dot_dir;
+ ret = -EREMOTE;
+ goto out;
}
- /* 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:"
- " 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;
- }
-
- /* 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");
- return -EREMOTE;
- }
-
- goto next_component;
-
-path_walk_complete:
- memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid));
- dprintk("<-- nfs4_path_walk() = 0\n");
- return 0;
+ memcpy(&server->fsid, &fsinfo.fattr->fsid, sizeof(server->fsid));
+out:
+ nfs_free_fattr(fsinfo.fattr);
+ dprintk("<-- nfs4_get_rootfh() = %d\n", ret);
+ return ret;
}
/*
struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh)
{
struct nfs_server *server = NFS_SB(sb);
- struct nfs_fattr fattr;
- struct dentry *mntroot;
+ struct nfs_fattr *fattr = NULL;
+ struct dentry *ret;
struct inode *inode;
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;
- }
-
/* get the info about the server and filesystem */
error = nfs4_server_capabilities(server, mntfh);
if (error < 0) {
return ERR_PTR(error);
}
+ fattr = nfs_alloc_fattr();
+ if (fattr == NULL)
+ 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->getattr(server, mntfh, fattr);
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, fattr);
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);
+ security_d_instantiate(ret, inode);
- if (!mntroot->d_op)
- mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops;
+ if (ret->d_op == NULL)
+ ret->d_op = server->nfs_client->rpc_ops->dentry_ops;
+out:
+ nfs_free_fattr(fattr);
dprintk("<-- nfs4_get_root()\n");
- return mntroot;
+ return ret;
}
#endif /* CONFIG_NFS_V4 */
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff