ecryptfs: avoid multiple aliases for directories

ecryptfs_lookup_interpose should use d_splice_alias(), not d_add()
(and return struct dentry * rather than int).  Get rid of
redundant dir_inode argument, while we are touching it...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 20 insertions, 20 deletions

diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 121114e9a464..91ebc8f18e20 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -324,9 +324,8 @@ static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
 /**
  * ecryptfs_lookup_interpose - Dentry interposition for a lookup
  */
-static int ecryptfs_lookup_interpose(struct dentry *dentry,
-                                     struct dentry *lower_dentry,
-                                     struct inode *dir_inode)
+static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
+                                     struct dentry *lower_dentry)
 {
         struct inode *inode, *lower_inode = d_inode(lower_dentry);
         struct ecryptfs_dentry_info *dentry_info;
@@ -339,11 +338,12 @@ static int ecryptfs_lookup_interpose(struct dentry *dentry,
                        "to allocate ecryptfs_dentry_info struct\n",
                         __func__);
                 dput(lower_dentry);
-                return -ENOMEM;
+                return ERR_PTR(-ENOMEM);
         }
 
         lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
-        fsstack_copy_attr_atime(dir_inode, d_inode(lower_dentry->d_parent));
+        fsstack_copy_attr_atime(d_inode(dentry->d_parent),
+                                d_inode(lower_dentry->d_parent));
         BUG_ON(!d_count(lower_dentry));
 
         ecryptfs_set_dentry_private(dentry, dentry_info);
@@ -353,27 +353,25 @@ static int ecryptfs_lookup_interpose(struct dentry *dentry,
         if (d_really_is_negative(lower_dentry)) {
                 /* We want to add because we couldn't find in lower */
                 d_add(dentry, NULL);
-                return 0;
+                return NULL;
         }
-        inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
+        inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
         if (IS_ERR(inode)) {
                 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
                        __func__, PTR_ERR(inode));
-                return PTR_ERR(inode);
+                return ERR_CAST(inode);
         }
         if (S_ISREG(inode->i_mode)) {
                 rc = ecryptfs_i_size_read(dentry, inode);
                 if (rc) {
                         make_bad_inode(inode);
-                        return rc;
+                        return ERR_PTR(rc);
                 }
         }
 
         if (inode->i_state & I_NEW)
                 unlock_new_inode(inode);
-        d_add(dentry, inode);
-
-        return rc;
+        return d_splice_alias(inode, dentry);
 }
 
 /**
@@ -393,6 +391,7 @@ 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 dentry *res;
         int rc = 0;
 
         lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
@@ -400,10 +399,10 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
                                       lower_dir_dentry,
                                       ecryptfs_dentry->d_name.len);
         if (IS_ERR(lower_dentry)) {
-                rc = PTR_ERR(lower_dentry);
                 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
-                                "[%d] on lower_dentry = [%pd]\n", __func__, rc,
-                                ecryptfs_dentry);
+                                "[%ld] on lower_dentry = [%pd]\n", __func__,
+                                PTR_ERR(lower_dentry), ecryptfs_dentry);
+                res = ERR_CAST(lower_dentry);
                 goto out;
         }
         if (d_really_is_positive(lower_dentry))
@@ -421,24 +420,25 @@ static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
         if (rc) {
                 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
                        "filename; rc = [%d]\n", __func__, rc);
+                res = ERR_PTR(rc);
                 goto out;
         }
         lower_dentry = lookup_one_len_unlocked(encrypted_and_encoded_name,
                                       lower_dir_dentry,
                                       encrypted_and_encoded_name_size);
         if (IS_ERR(lower_dentry)) {
-                rc = PTR_ERR(lower_dentry);
                 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
-                                "[%d] on lower_dentry = [%s]\n", __func__, rc,
+                                "[%ld] on lower_dentry = [%s]\n", __func__,
+                                PTR_ERR(lower_dentry),
                                 encrypted_and_encoded_name);
+                res = ERR_CAST(lower_dentry);
                 goto out;
         }
 interpose:
-        rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
-                                       ecryptfs_dir_inode);
+        res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
 out:
         kfree(encrypted_and_encoded_name);
-        return ERR_PTR(rc);
+        return res;
 }
 
 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,