eCryptfs: Revert "dont call lookup_one_len to avoid NULL nameidata"

This reverts commit 21edad32205e97dc7ccb81a85234c77e760364c8 and commit
93c3fe40c279f002906ad14584c30671097d4394, which fixed a regression by
the former.

Al Viro pointed out bypassed dcache lookups in
ecryptfs_new_lower_dentry(), misuse of vfs_path_lookup() in
ecryptfs_lookup_one_lower() and a dislike of passing nameidata to the
lower filesystem.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index bd33f87..fc44823 100644 (file)
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -348,75 +348,6 @@ out:
        return rc;
 }
 
-/**
- * ecryptfs_new_lower_dentry
- * @name: The name of the new dentry.
- * @lower_dir_dentry: Parent directory of the new dentry.
- * @nd: nameidata from last lookup.
- *
- * Create a new dentry or get it from lower parent dir.
- */
-static struct dentry *
-ecryptfs_new_lower_dentry(struct qstr *name, struct dentry *lower_dir_dentry,
-                         struct nameidata *nd)
-{
-       struct dentry *new_dentry;
-       struct dentry *tmp;
-       struct inode *lower_dir_inode;
-
-       lower_dir_inode = lower_dir_dentry->d_inode;
-
-       tmp = d_alloc(lower_dir_dentry, name);
-       if (!tmp)
-               return ERR_PTR(-ENOMEM);
-
-       mutex_lock(&lower_dir_inode->i_mutex);
-       new_dentry = lower_dir_inode->i_op->lookup(lower_dir_inode, tmp, nd);
-       mutex_unlock(&lower_dir_inode->i_mutex);
-
-       if (!new_dentry)
-               new_dentry = tmp;
-       else
-               dput(tmp);
-
-       return new_dentry;
-}
-
-
-/**
- * ecryptfs_lookup_one_lower
- * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
- * @lower_dir_dentry: lower parent directory
- * @name: lower file name
- *
- * Get the lower dentry from vfs. If lower dentry does not exist yet,
- * create it.
- */
-static struct dentry *
-ecryptfs_lookup_one_lower(struct dentry *ecryptfs_dentry,
-                         struct dentry *lower_dir_dentry, struct qstr *name)
-{
-       struct nameidata nd;
-       struct vfsmount *lower_mnt;
-       int err;
-
-       lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
-                                   ecryptfs_dentry->d_parent));
-       err = vfs_path_lookup(lower_dir_dentry, lower_mnt, name->name , 0, &nd);
-       mntput(lower_mnt);
-
-       if (!err) {
-               /* we dont need the mount */
-               mntput(nd.path.mnt);
-               return nd.path.dentry;
-       }
-       if (err != -ENOENT)
-               return ERR_PTR(err);
-
-       /* create a new lower dentry */
-       return ecryptfs_new_lower_dentry(name, lower_dir_dentry, &nd);
-}
-
 /**
  * ecryptfs_lookup
  * @ecryptfs_dir_inode: The eCryptfs directory inode
@@ -434,7 +365,6 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
        size_t encrypted_and_encoded_name_size;
        struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
        struct dentry *lower_dir_dentry, *lower_dentry;
-       struct qstr lower_name;
        int rc = 0;
 
        if ((ecryptfs_dentry->d_name.len == 1
@@ -444,20 +374,14 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                goto out_d_drop;
        }
        lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
-       lower_name.name = ecryptfs_dentry->d_name.name;
-       lower_name.len = ecryptfs_dentry->d_name.len;
-       lower_name.hash = ecryptfs_dentry->d_name.hash;
-       if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
-               rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
-                               lower_dir_dentry->d_inode, &lower_name);
-               if (rc < 0)
-                       goto out_d_drop;
-       }
-       lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry,
-                                                lower_dir_dentry, &lower_name);
+       mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
+       lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
+                                     lower_dir_dentry,
+                                     ecryptfs_dentry->d_name.len);
+       mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
        if (IS_ERR(lower_dentry)) {
                rc = PTR_ERR(lower_dentry);
-               ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned "
+               ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
                                "[%d] on lower_dentry = [%s]\n", __func__, rc,
                                encrypted_and_encoded_name);
                goto out_d_drop;
@@ -479,20 +403,14 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                       "filename; rc = [%d]\n", __func__, rc);
                goto out_d_drop;
        }
-       lower_name.name = encrypted_and_encoded_name;
-       lower_name.len = encrypted_and_encoded_name_size;
-       lower_name.hash = full_name_hash(lower_name.name, lower_name.len);
-       if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
-               rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
-                               lower_dir_dentry->d_inode, &lower_name);
-               if (rc < 0)
-                       goto out_d_drop;
-       }
-       lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry,
-                                                lower_dir_dentry, &lower_name);
+       mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
+       lower_dentry = lookup_one_len(encrypted_and_encoded_name,
+                                     lower_dir_dentry,
+                                     encrypted_and_encoded_name_size);
+       mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
        if (IS_ERR(lower_dentry)) {
                rc = PTR_ERR(lower_dentry);
-               ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned "
+               ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
                                "[%d] on lower_dentry = [%s]\n", __func__, rc,
                                encrypted_and_encoded_name);
                goto out_d_drop;