ext4 crypto: teach ext4_htree_store_dirent() to store decrypted filenames

For encrypted directories, we need to pass in a separate parameter for
the decrypted filename, since the directory entry contains the
encrypted filename.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

4 files changed, 35 insertions, 13 deletions

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 9e1e9e7869cb..315f13ad382e 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -382,10 +382,15 @@ void ext4_htree_free_dir_info(struct dir_private_info *p)
 
 /*
  * Given a directory entry, enter it into the fname rb tree.
+ *
+ * When filename encryption is enabled, the dirent will hold the
+ * encrypted filename, while the htree will hold decrypted filename.
+ * The decrypted filename is passed in via ent_name.  parameter.
  */
 int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
                              __u32 minor_hash,
-                             struct ext4_dir_entry_2 *dirent)
+                            struct ext4_dir_entry_2 *dirent,
+                            struct ext4_str *ent_name)
 {
         struct rb_node **p, *parent = NULL;
         struct fname *fname, *new_fn;
@@ -396,17 +401,17 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
         p = &info->root.rb_node;
 
         /* Create and allocate the fname structure */
-        len = sizeof(struct fname) + dirent->name_len + 1;
+        len = sizeof(struct fname) + ent_name->len + 1;
         new_fn = kzalloc(len, GFP_KERNEL);
         if (!new_fn)
                 return -ENOMEM;
         new_fn->hash = hash;
         new_fn->minor_hash = minor_hash;
         new_fn->inode = le32_to_cpu(dirent->inode);
-        new_fn->name_len = dirent->name_len;
+        new_fn->name_len = ent_name->len;
         new_fn->file_type = dirent->file_type;
-        memcpy(new_fn->name, dirent->name, dirent->name_len);
-        new_fn->name[dirent->name_len] = 0;
+        memcpy(new_fn->name, ent_name->name, ent_name->len);
+        new_fn->name[ent_name->len] = 0;
 
         while (*p) {
                 parent = *p;
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 3462532b227f..ba75838f3588 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2142,8 +2142,9 @@ extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
                                         (de), (bh), (buf), (size), (offset)))
 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
-                                    __u32 minor_hash,
-                                    struct ext4_dir_entry_2 *dirent);
+                                __u32 minor_hash,
+                                struct ext4_dir_entry_2 *dirent,
+                                struct ext4_str *ent_name);
 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
                              struct buffer_head *bh,
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 8b64d715e476..661f0b8dcfe0 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1327,6 +1327,7 @@ int htree_inlinedir_to_tree(struct file *dir_file,
         struct ext4_iloc iloc;
         void *dir_buf = NULL;
         struct ext4_dir_entry_2 fake;
+        struct ext4_str tmp_str;
 
         ret = ext4_get_inode_loc(inode, &iloc);
         if (ret)
@@ -1398,8 +1399,10 @@ int htree_inlinedir_to_tree(struct file *dir_file,
                         continue;
                 if (de->inode == 0)
                         continue;
-                err = ext4_htree_store_dirent(dir_file,
-                                   hinfo->hash, hinfo->minor_hash, de);
+                tmp_str.name = de->name;
+                tmp_str.len = de->name_len;
+                err = ext4_htree_store_dirent(dir_file, hinfo->hash,
+                                              hinfo->minor_hash, de, &tmp_str);
                 if (err) {
                         count = err;
                         goto out;
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 77a63ff4aeb9..8cef115ee64a 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -877,6 +877,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
         struct buffer_head *bh;
         struct ext4_dir_entry_2 *de, *top;
         int err = 0, count = 0;
+        struct ext4_str tmp_str;
 
         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
                                                         (unsigned long)block));
@@ -903,8 +904,11 @@ static int htree_dirblock_to_tree(struct file *dir_file,
                         continue;
                 if (de->inode == 0)
                         continue;
-                if ((err = ext4_htree_store_dirent(dir_file,
-                                   hinfo->hash, hinfo->minor_hash, de)) != 0) {
+                tmp_str.name = de->name;
+                tmp_str.len = de->name_len;
+                err = ext4_htree_store_dirent(dir_file,
+                           hinfo->hash, hinfo->minor_hash, de, &tmp_str);
+                if (err != 0) {
                         brelse(bh);
                         return err;
                 }
@@ -934,6 +938,7 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
         int count = 0;
         int ret, err;
         __u32 hashval;
+        struct ext4_str tmp_str;
 
         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
                        start_hash, start_minor_hash));
@@ -969,14 +974,22 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
         /* Add '.' and '..' from the htree header */
         if (!start_hash && !start_minor_hash) {
                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
-                if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
+                tmp_str.name = de->name;
+                tmp_str.len = de->name_len;
+                err = ext4_htree_store_dirent(dir_file, 0, 0,
+                                              de, &tmp_str);
+                if (err != 0)
                         goto errout;
                 count++;
         }
         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
-                if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
+                tmp_str.name = de->name;
+                tmp_str.len = de->name_len;
+                err = ext4_htree_store_dirent(dir_file, 2, 0,
+                                              de, &tmp_str);
+                if (err != 0)
                         goto errout;
                 count++;
         }