ext4 crypto: partial update to namei.c for fname crypto

Modifies dx_show_leaf and dx_probe to support fname encryption.
Filename encryption not yet enabled.

Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index eb11a1b8a3d5435ff04ff2cd6ca0b27f9dbcea85..85add9a9e1cd646629b1affa023de4b10f2bdf5a 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -585,8 +585,10 @@ struct stats
        unsigned bcount;
 };
 
-static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_entry_2 *de,
-                                int size, int show_names)
+static struct stats dx_show_leaf(struct inode *dir,
+                               struct dx_hash_info *hinfo,
+                               struct ext4_dir_entry_2 *de,
+                               int size, int show_names)
 {
        unsigned names = 0, space = 0;
        char *base = (char *) de;
@@ -599,12 +601,80 @@ static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_ent
                {
                        if (show_names)
                        {
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+                               int len;
+                               char *name;
+                               struct ext4_str fname_crypto_str
+                                       = {.name = NULL, .len = 0};
+                               struct ext4_fname_crypto_ctx *ctx = NULL;
+                               int res;
+
+                               name  = de->name;
+                               len = de->name_len;
+                               ctx = ext4_get_fname_crypto_ctx(dir,
+                                                               EXT4_NAME_LEN);
+                               if (IS_ERR(ctx)) {
+                                       printk(KERN_WARNING "Error acquiring"
+                                       " crypto ctxt--skipping crypto\n");
+                                       ctx = NULL;
+                               }
+                               if (ctx == NULL) {
+                                       /* Directory is not encrypted */
+                                       ext4fs_dirhash(de->name,
+                                               de->name_len, &h);
+                                       printk("%*.s:(U)%x.%u ", len,
+                                              name, h.hash,
+                                              (unsigned) ((char *) de
+                                                          - base));
+                               } else {
+                                       /* Directory is encrypted */
+                                       res = ext4_fname_crypto_alloc_buffer(
+                                               ctx, de->name_len,
+                                               &fname_crypto_str);
+                                       if (res < 0) {
+                                               printk(KERN_WARNING "Error "
+                                                       "allocating crypto "
+                                                       "buffer--skipping "
+                                                       "crypto\n");
+                                               ext4_put_fname_crypto_ctx(&ctx);
+                                               ctx = NULL;
+                                       }
+                                       res = ext4_fname_disk_to_usr(ctx, de,
+                                                       &fname_crypto_str);
+                                       if (res < 0) {
+                                               printk(KERN_WARNING "Error "
+                                                       "converting filename "
+                                                       "from disk to usr"
+                                                       "\n");
+                                               name = "??";
+                                               len = 2;
+                                       } else {
+                                               name = fname_crypto_str.name;
+                                               len = fname_crypto_str.len;
+                                       }
+                                       res = ext4_fname_disk_to_hash(ctx, de,
+                                                                     &h);
+                                       if (res < 0) {
+                                               printk(KERN_WARNING "Error "
+                                                       "converting filename "
+                                                       "from disk to htree"
+                                                       "\n");
+                                               h.hash = 0xDEADBEEF;
+                                       }
+                                       printk("%*.s:(E)%x.%u ", len, name,
+                                              h.hash, (unsigned) ((char *) de
+                                                                  - base));
+                                       ext4_put_fname_crypto_ctx(&ctx);
+                                       ext4_fname_crypto_free_buffer(
+                                               &fname_crypto_str);
+                               }
+#else
                                int len = de->name_len;
                                char *name = de->name;
-                               while (len--) printk("%c", *name++);
                                ext4fs_dirhash(de->name, de->name_len, &h);
-                               printk(":%x.%u ", h.hash,
+                               printk("%*.s:%x.%u ", len, name, h.hash,
                                       (unsigned) ((char *) de - base));
+#endif
                        }
                        space += EXT4_DIR_REC_LEN(de->name_len);
                        names++;
@@ -622,7 +692,6 @@ struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
        unsigned count = dx_get_count(entries), names = 0, space = 0, i;
        unsigned bcount = 0;
        struct buffer_head *bh;
-       int err;
        printk("%i indexed blocks...\n", count);
        for (i = 0; i < count; i++, entries++)
        {
@@ -636,7 +705,8 @@ struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
                        continue;
                stats = levels?
                   dx_show_entries(hinfo, dir, ((struct dx_node *) bh->b_data)->entries, levels - 1):
-                  dx_show_leaf(hinfo, (struct ext4_dir_entry_2 *) bh->b_data, blocksize, 0);
+                  dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *)
+                       bh->b_data, blocksize, 0);
                names += stats.names;
                space += stats.space;
                bcount += stats.bcount;
@@ -686,8 +756,28 @@ dx_probe(const struct qstr *d_name, struct inode *dir,
        if (hinfo->hash_version <= DX_HASH_TEA)
                hinfo->hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
        hinfo->seed = EXT4_SB(dir->i_sb)->s_hash_seed;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+       if (d_name) {
+               struct ext4_fname_crypto_ctx *ctx = NULL;
+               int res;
+
+               /* Check if the directory is encrypted */
+               ctx = ext4_get_fname_crypto_ctx(dir, EXT4_NAME_LEN);
+               if (IS_ERR(ctx)) {
+                       ret_err = ERR_PTR(PTR_ERR(ctx));
+                       goto fail;
+               }
+               res = ext4_fname_usr_to_hash(ctx, d_name, hinfo);
+               if (res < 0) {
+                       ret_err = ERR_PTR(res);
+                       goto fail;
+               }
+               ext4_put_fname_crypto_ctx(&ctx);
+       }
+#else
        if (d_name)
                ext4fs_dirhash(d_name->name, d_name->len, hinfo);
+#endif
        hash = hinfo->hash;
 
        if (root->info.unused_flags & 1) {
@@ -772,6 +862,7 @@ fail:
                brelse(frame->bh);
                frame--;
        }
+
        if (ret_err == ERR_PTR(ERR_BAD_DX_DIR))
                ext4_warning(dir->i_sb,
                             "Corrupt dir inode %lu, running e2fsck is "
@@ -1604,8 +1695,10 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
                initialize_dirent_tail(t, blocksize);
        }
 
-       dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
-       dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
+       dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data1,
+                       blocksize, 1));
+       dxtrace(dx_show_leaf(dir, hinfo, (struct ext4_dir_entry_2 *) data2,
+                       blocksize, 1));
 
        /* Which block gets the new entry? */
        if (hinfo->hash >= hash2) {