ext4: fix up test_dummy_encryption handling for new mount API
[linux-2.6-microblaze.git] / fs / ext4 / super.c
index 13d562d..845f2f8 100644 (file)
@@ -87,7 +87,7 @@ static struct inode *ext4_get_journal_inode(struct super_block *sb,
 static int ext4_validate_options(struct fs_context *fc);
 static int ext4_check_opt_consistency(struct fs_context *fc,
                                      struct super_block *sb);
-static int ext4_apply_options(struct fs_context *fc, struct super_block *sb);
+static void ext4_apply_options(struct fs_context *fc, struct super_block *sb);
 static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param);
 static int ext4_get_tree(struct fs_context *fc);
 static int ext4_reconfigure(struct fs_context *fc);
@@ -1870,31 +1870,12 @@ ext4_sb_read_encoding(const struct ext4_super_block *es)
 }
 #endif
 
-static int ext4_set_test_dummy_encryption(struct super_block *sb, char *arg)
-{
-#ifdef CONFIG_FS_ENCRYPTION
-       struct ext4_sb_info *sbi = EXT4_SB(sb);
-       int err;
-
-       err = fscrypt_set_test_dummy_encryption(sb, arg,
-                                               &sbi->s_dummy_enc_policy);
-       if (err) {
-               ext4_msg(sb, KERN_WARNING,
-                        "Error while setting test dummy encryption [%d]", err);
-               return err;
-       }
-       ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
-#endif
-       return 0;
-}
-
 #define EXT4_SPEC_JQUOTA                       (1 <<  0)
 #define EXT4_SPEC_JQFMT                                (1 <<  1)
 #define EXT4_SPEC_DATAJ                                (1 <<  2)
 #define EXT4_SPEC_SB_BLOCK                     (1 <<  3)
 #define EXT4_SPEC_JOURNAL_DEV                  (1 <<  4)
 #define EXT4_SPEC_JOURNAL_IOPRIO               (1 <<  5)
-#define EXT4_SPEC_DUMMY_ENCRYPTION             (1 <<  6)
 #define EXT4_SPEC_s_want_extra_isize           (1 <<  7)
 #define EXT4_SPEC_s_max_batch_time             (1 <<  8)
 #define EXT4_SPEC_s_min_batch_time             (1 <<  9)
@@ -1911,7 +1892,7 @@ static int ext4_set_test_dummy_encryption(struct super_block *sb, char *arg)
 
 struct ext4_fs_context {
        char            *s_qf_names[EXT4_MAXQUOTAS];
-       char            *test_dummy_enc_arg;
+       struct fscrypt_dummy_policy dummy_enc_policy;
        int             s_jquota_fmt;   /* Format of quota to use */
 #ifdef CONFIG_EXT4_DEBUG
        int s_fc_debug_max_replay;
@@ -1953,7 +1934,7 @@ static void ext4_fc_free(struct fs_context *fc)
        for (i = 0; i < EXT4_MAXQUOTAS; i++)
                kfree(ctx->s_qf_names[i]);
 
-       kfree(ctx->test_dummy_enc_arg);
+       fscrypt_free_dummy_policy(&ctx->dummy_enc_policy);
        kfree(ctx);
 }
 
@@ -2029,6 +2010,29 @@ static int unnote_qf_name(struct fs_context *fc, int qtype)
 }
 #endif
 
+static int ext4_parse_test_dummy_encryption(const struct fs_parameter *param,
+                                           struct ext4_fs_context *ctx)
+{
+       int err;
+
+       if (!IS_ENABLED(CONFIG_FS_ENCRYPTION)) {
+               ext4_msg(NULL, KERN_WARNING,
+                        "test_dummy_encryption option not supported");
+               return -EINVAL;
+       }
+       err = fscrypt_parse_test_dummy_encryption(param,
+                                                 &ctx->dummy_enc_policy);
+       if (err == -EINVAL) {
+               ext4_msg(NULL, KERN_WARNING,
+                        "Value of option \"%s\" is unrecognized", param->key);
+       } else if (err == -EEXIST) {
+               ext4_msg(NULL, KERN_WARNING,
+                        "Conflicting test_dummy_encryption options");
+               return -EINVAL;
+       }
+       return err;
+}
+
 #define EXT4_SET_CTX(name)                                             \
 static inline void ctx_set_##name(struct ext4_fs_context *ctx,         \
                                  unsigned long flag)                   \
@@ -2291,29 +2295,7 @@ static int ext4_parse_param(struct fs_context *fc, struct fs_parameter *param)
                ctx->spec |= EXT4_SPEC_JOURNAL_IOPRIO;
                return 0;
        case Opt_test_dummy_encryption:
-#ifdef CONFIG_FS_ENCRYPTION
-               if (param->type == fs_value_is_flag) {
-                       ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
-                       ctx->test_dummy_enc_arg = NULL;
-                       return 0;
-               }
-               if (*param->string &&
-                   !(!strcmp(param->string, "v1") ||
-                     !strcmp(param->string, "v2"))) {
-                       ext4_msg(NULL, KERN_WARNING,
-                                "Value of option \"%s\" is unrecognized",
-                                param->key);
-                       return -EINVAL;
-               }
-               ctx->spec |= EXT4_SPEC_DUMMY_ENCRYPTION;
-               ctx->test_dummy_enc_arg = kmemdup_nul(param->string, param->size,
-                                                     GFP_KERNEL);
-               return 0;
-#else
-               ext4_msg(NULL, KERN_WARNING,
-                        "test_dummy_encryption option not supported");
-               return -EINVAL;
-#endif
+               return ext4_parse_test_dummy_encryption(param, ctx);
        case Opt_dax:
        case Opt_dax_type:
 #ifdef CONFIG_FS_DAX
@@ -2504,7 +2486,8 @@ parse_failed:
        if (s_ctx->spec & EXT4_SPEC_JOURNAL_IOPRIO)
                m_ctx->journal_ioprio = s_ctx->journal_ioprio;
 
-       ret = ext4_apply_options(fc, sb);
+       ext4_apply_options(fc, sb);
+       ret = 0;
 
 out_free:
        if (fc) {
@@ -2673,11 +2656,11 @@ err_jquota_specified:
 static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
                                            struct super_block *sb)
 {
-#ifdef CONFIG_FS_ENCRYPTION
        const struct ext4_fs_context *ctx = fc->fs_private;
        const struct ext4_sb_info *sbi = EXT4_SB(sb);
+       int err;
 
-       if (!(ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION))
+       if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy))
                return 0;
 
        if (!ext4_has_feature_encrypt(sb)) {
@@ -2691,14 +2674,46 @@ static int ext4_check_test_dummy_encryption(const struct fs_context *fc,
         * needed to allow it to be set or changed during remount.  We do allow
         * it to be specified during remount, but only if there is no change.
         */
-       if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE &&
-           !sbi->s_dummy_enc_policy.policy) {
+       if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+               if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
+                                                &ctx->dummy_enc_policy))
+                       return 0;
                ext4_msg(NULL, KERN_WARNING,
-                        "Can't set test_dummy_encryption on remount");
+                        "Can't set or change test_dummy_encryption on remount");
                return -EINVAL;
        }
-#endif /* CONFIG_FS_ENCRYPTION */
-       return 0;
+       /* Also make sure s_mount_opts didn't contain a conflicting value. */
+       if (fscrypt_is_dummy_policy_set(&sbi->s_dummy_enc_policy)) {
+               if (fscrypt_dummy_policies_equal(&sbi->s_dummy_enc_policy,
+                                                &ctx->dummy_enc_policy))
+                       return 0;
+               ext4_msg(NULL, KERN_WARNING,
+                        "Conflicting test_dummy_encryption options");
+               return -EINVAL;
+       }
+       /*
+        * fscrypt_add_test_dummy_key() technically changes the super_block, so
+        * technically it should be delayed until ext4_apply_options() like the
+        * other changes.  But since we never get here for remounts (see above),
+        * and this is the last chance to report errors, we do it here.
+        */
+       err = fscrypt_add_test_dummy_key(sb, &ctx->dummy_enc_policy);
+       if (err)
+               ext4_msg(NULL, KERN_WARNING,
+                        "Error adding test dummy encryption key [%d]", err);
+       return err;
+}
+
+static void ext4_apply_test_dummy_encryption(struct ext4_fs_context *ctx,
+                                            struct super_block *sb)
+{
+       if (!fscrypt_is_dummy_policy_set(&ctx->dummy_enc_policy) ||
+           /* if already set, it was already verified to be the same */
+           fscrypt_is_dummy_policy_set(&EXT4_SB(sb)->s_dummy_enc_policy))
+               return;
+       EXT4_SB(sb)->s_dummy_enc_policy = ctx->dummy_enc_policy;
+       memset(&ctx->dummy_enc_policy, 0, sizeof(ctx->dummy_enc_policy));
+       ext4_msg(sb, KERN_WARNING, "Test dummy encryption mode enabled");
 }
 
 static int ext4_check_opt_consistency(struct fs_context *fc,
@@ -2785,11 +2800,10 @@ fail_dax_change_remount:
        return ext4_check_quota_consistency(fc, sb);
 }
 
-static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
+static void ext4_apply_options(struct fs_context *fc, struct super_block *sb)
 {
        struct ext4_fs_context *ctx = fc->fs_private;
        struct ext4_sb_info *sbi = fc->s_fs_info;
-       int ret = 0;
 
        sbi->s_mount_opt &= ~ctx->mask_s_mount_opt;
        sbi->s_mount_opt |= ctx->vals_s_mount_opt;
@@ -2825,11 +2839,7 @@ static int ext4_apply_options(struct fs_context *fc, struct super_block *sb)
 #endif
 
        ext4_apply_quota_options(fc, sb);
-
-       if (ctx->spec & EXT4_SPEC_DUMMY_ENCRYPTION)
-               ret = ext4_set_test_dummy_encryption(sb, ctx->test_dummy_enc_arg);
-
-       return ret;
+       ext4_apply_test_dummy_encryption(ctx, sb);
 }
 
 
@@ -4552,9 +4562,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
        if (err < 0)
                goto failed_mount;
 
-       err = ext4_apply_options(fc, sb);
-       if (err < 0)
-               goto failed_mount;
+       ext4_apply_options(fc, sb);
 
 #if IS_ENABLED(CONFIG_UNICODE)
        if (ext4_has_feature_casefold(sb) && !sb->s_encoding) {