teach-ext4_htree_store_dirent-to-store-decrypted-filenames

   1 ext4 crypto: teach ext4_htree_store_dirent() to store decrypted filenames
   2
   3 From: Theodore Ts'o <tytso@mit.edu>
   4
   5 For encrypted directories, we need to pass in a separate parameter for
   6 the decrypted filename, since the directory entry contains the
   7 encrypted filename.
   8
   9 Change-Id: I2d1a78e65cb81152cae108ce7faadc28b52e0abe
  10 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  11
  12 ---
  13  fs/ext4/dir.c    | 15 ++++++++++-----
  14  fs/ext4/ext4.h   |  5 +++--
  15  fs/ext4/inline.c |  7 +++++--
  16  fs/ext4/namei.c  | 21 +++++++++++++++++----
  17  4 files changed, 35 insertions(+), 13 deletions(-)
  18
  19 diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
  20 index c24143e..f67f955 100644
  21 --- a/fs/ext4/dir.c
  22 +++ b/fs/ext4/dir.c
  23 @@ -384,10 +384,15 @@ void ext4_htree_free_dir_info(struct dir_private_info *p)
  24
  25  /*
  26   * Given a directory entry, enter it into the fname rb tree.
  27 + *
  28 + * When filename encryption is enabled, the dirent will hold the
  29 + * encrypted filename, while the htree will hold decrypted filename.
  30 + * The decrypted filename is passed in via ent_name.  parameter.
  31   */
  32  int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
  33                              __u32 minor_hash,
  34 -                            struct ext4_dir_entry_2 *dirent)
  35 +                           struct ext4_dir_entry_2 *dirent,
  36 +                           struct ext4_str *ent_name)
  37  {
  38         struct rb_node **p, *parent = NULL;
  39         struct fname *fname, *new_fn;
  40 @@ -398,17 +403,17 @@ int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
  41         p = &info->root.rb_node;
  42
  43         /* Create and allocate the fname structure */
  44 -       len = sizeof(struct fname) + dirent->name_len + 1;
  45 +       len = sizeof(struct fname) + ent_name->len + 1;
  46         new_fn = kzalloc(len, GFP_KERNEL);
  47         if (!new_fn)
  48                 return -ENOMEM;
  49         new_fn->hash = hash;
  50         new_fn->minor_hash = minor_hash;
  51         new_fn->inode = le32_to_cpu(dirent->inode);
  52 -       new_fn->name_len = dirent->name_len;
  53 +       new_fn->name_len = ent_name->len;
  54         new_fn->file_type = dirent->file_type;
  55 -       memcpy(new_fn->name, dirent->name, dirent->name_len);
  56 -       new_fn->name[dirent->name_len] = 0;
  57 +       memcpy(new_fn->name, ent_name->name, ent_name->len);
  58 +       new_fn->name[ent_name->len] = 0;
  59
  60         while (*p) {
  61                 parent = *p;
  62 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  63 index 89ca8a6..4da5c65 100644
  64 --- a/fs/ext4/ext4.h
  65 +++ b/fs/ext4/ext4.h
  66 @@ -2128,8 +2128,9 @@ extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
  67         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
  68                                         (de), (bh), (buf), (size), (offset)))
  69  extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
  70 -                                   __u32 minor_hash,
  71 -                                   struct ext4_dir_entry_2 *dirent);
  72 +                               __u32 minor_hash,
  73 +                               struct ext4_dir_entry_2 *dirent,
  74 +                               struct ext4_str *ent_name);
  75  extern void ext4_htree_free_dir_info(struct dir_private_info *p);
  76  extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
  77                              struct buffer_head *bh,
  78 diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
  79 index 4b143fe..056ef06 100644
  80 --- a/fs/ext4/inline.c
  81 +++ b/fs/ext4/inline.c
  82 @@ -1327,6 +1327,7 @@ int htree_inlinedir_to_tree(struct file *dir_file,
  83         struct ext4_iloc iloc;
  84         void *dir_buf = NULL;
  85         struct ext4_dir_entry_2 fake;
  86 +       struct ext4_str tmp_str;
  87
  88         ret = ext4_get_inode_loc(inode, &iloc);
  89         if (ret)
  90 @@ -1398,8 +1399,10 @@ int htree_inlinedir_to_tree(struct file *dir_file,
  91                         continue;
  92                 if (de->inode == 0)
  93                         continue;
  94 -               err = ext4_htree_store_dirent(dir_file,
  95 -                                  hinfo->hash, hinfo->minor_hash, de);
  96 +               tmp_str.name = de->name;
  97 +               tmp_str.len = de->name_len;
  98 +               err = ext4_htree_store_dirent(dir_file, hinfo->hash,
  99 +                                             hinfo->minor_hash, de, &tmp_str);
 100                 if (err) {
 101                         count = err;
 102                         goto out;
 103 diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
 104 index 262aa1c..57cae22 100644
 105 --- a/fs/ext4/namei.c
 106 +++ b/fs/ext4/namei.c
 107 @@ -880,6 +880,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 108         struct buffer_head *bh;
 109         struct ext4_dir_entry_2 *de, *top;
 110         int err = 0, count = 0;
 111 +       struct ext4_str tmp_str;
 112
 113         dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
 114                                                         (unsigned long)block));
 115 @@ -906,8 +907,11 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 116                         continue;
 117                 if (de->inode == 0)
 118                         continue;
 119 -               if ((err = ext4_htree_store_dirent(dir_file,
 120 -                                  hinfo->hash, hinfo->minor_hash, de)) != 0) {
 121 +               tmp_str.name = de->name;
 122 +               tmp_str.len = de->name_len;
 123 +               err = ext4_htree_store_dirent(dir_file,
 124 +                          hinfo->hash, hinfo->minor_hash, de, &tmp_str);
 125 +               if (err != 0) {
 126                         brelse(bh);
 127                         return err;
 128                 }
 129 @@ -937,6 +941,7 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 130         int count = 0;
 131         int ret, err;
 132         __u32 hashval;
 133 +       struct ext4_str tmp_str;
 134
 135         dxtrace(printk(KERN_DEBUG "In htree_fill_tree, start hash: %x:%x\n",
 136                        start_hash, start_minor_hash));
 137 @@ -972,14 +977,22 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 138         /* Add '.' and '..' from the htree header */
 139         if (!start_hash && !start_minor_hash) {
 140                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 141 -               if ((err = ext4_htree_store_dirent(dir_file, 0, 0, de)) != 0)
 142 +               tmp_str.name = de->name;
 143 +               tmp_str.len = de->name_len;
 144 +               err = ext4_htree_store_dirent(dir_file, 0, 0,
 145 +                                             de, &tmp_str);
 146 +               if (err != 0)
 147                         goto errout;
 148                 count++;
 149         }
 150         if (start_hash < 2 || (start_hash ==2 && start_minor_hash==0)) {
 151                 de = (struct ext4_dir_entry_2 *) frames[0].bh->b_data;
 152                 de = ext4_next_entry(de, dir->i_sb->s_blocksize);
 153 -               if ((err = ext4_htree_store_dirent(dir_file, 2, 0, de)) != 0)
 154 +               tmp_str.name = de->name;
 155 +               tmp_str.len = de->name_len;
 156 +               err = ext4_htree_store_dirent(dir_file, 2, 0,
 157 +                                             de, &tmp_str);
 158 +               if (err != 0)
 159                         goto errout;
 160                 count++;
 161         }