Re: [PATCH] ceph: fix up test_dummy_encryption handling for new mount API

[Xiubo Li <xiubli@redhat.com>]

On 7/13/22 6:42 PM, Jeff Layton wrote:
> On Wed, 2022-07-13 at 16:56 +0800, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>>  From Eric the "fscrypt_set_test_dummy_encryption()" will be removed
>> in the next circle. Switch it to new APIs.
>>
>> Cc: Eric Biggers <ebiggers@kernel.org>
>> Cc: Jeff Layton <jlayton@kernel.org>
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>   fs/ceph/crypto.c |  4 +--
>>   fs/ceph/super.c  | 94 ++++++++++++++++++++++++------------------------
>>   fs/ceph/super.h  |  5 ++-
>>   3 files changed, 52 insertions(+), 51 deletions(-)
>>
>> diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
>> index 7e0c48e12554..5b807f8f4c69 100644
>> --- a/fs/ceph/crypto.c
>> +++ b/fs/ceph/crypto.c
>> @@ -127,7 +127,7 @@ static bool ceph_crypt_empty_dir(struct inode *inode)
>>   
>>   static const union fscrypt_policy *ceph_get_dummy_policy(struct super_block *sb)
>>   {
>> -	return ceph_sb_to_client(sb)->dummy_enc_policy.policy;
>> +	return ceph_sb_to_client(sb)->fsc_dummy_enc_policy.policy;
>>   }
>>   
>>   static struct fscrypt_operations ceph_fscrypt_ops = {
>> @@ -144,7 +144,7 @@ void ceph_fscrypt_set_ops(struct super_block *sb)
>>   
>>   void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc)
>>   {
>> -	fscrypt_free_dummy_policy(&fsc->dummy_enc_policy);
>> +	fscrypt_free_dummy_policy(&fsc->fsc_dummy_enc_policy);
>>   }
>>   
>>   int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
>> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
>> index fa59a804b32c..4ac4a90755a2 100644
>> --- a/fs/ceph/super.c
>> +++ b/fs/ceph/super.c
>> @@ -591,10 +591,16 @@ static int ceph_parse_mount_param(struct fs_context *fc,
>>   		break;
>>   	case Opt_test_dummy_encryption:
>>   #ifdef CONFIG_FS_ENCRYPTION
>> -		kfree(fsopt->test_dummy_encryption);
>> -		fsopt->test_dummy_encryption = param->string;
>> -		param->string = NULL;
>> -		fsopt->flags |= CEPH_MOUNT_OPT_TEST_DUMMY_ENC;
>> +		fscrypt_free_dummy_policy(&fsopt->dummy_enc_policy);
>> +		ret = fscrypt_parse_test_dummy_encryption(param,
>> +						&fsopt->dummy_enc_policy);
>> +		if (ret == -EINVAL) {
>> +			warnfc(fc, "Value of option \"%s\" is unrecognized",
>> +			       param->key);
>> +		} else if (ret == -EEXIST) {
>> +			warnfc(fc, "Conflicting test_dummy_encryption options");
>> +			ret = -EINVAL;
>> +		}
>>   #else
>>   		warnfc(fc,
>>   		       "FS encryption not supported: test_dummy_encryption mount option ignored");
>> @@ -620,7 +626,7 @@ static void destroy_mount_options(struct ceph_mount_options *args)
>>   	kfree(args->server_path);
>>   	kfree(args->fscache_uniq);
>>   	kfree(args->mon_addr);
>> -	kfree(args->test_dummy_encryption);
>> +	fscrypt_free_dummy_policy(&args->dummy_enc_policy);
>>   	kfree(args);
>>   }
>>   
>> @@ -1080,51 +1086,47 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc,
>>   	return root;
>>   }
>>   
>> -#ifdef CONFIG_FS_ENCRYPTION
>> -static int ceph_set_test_dummy_encryption(struct super_block *sb, struct fs_context *fc,
>> -						struct ceph_mount_options *fsopt)
>> +static int ceph_apply_test_dummy_encryption(struct super_block *sb,
>> +					    struct fs_context *fc,
>> +					    struct ceph_mount_options *fsopt)
>>   {
>> -	/*
>> -	 * No changing encryption context on remount. Note that
>> -	 * fscrypt_set_test_dummy_encryption will validate the version
>> -	 * string passed in (if any).
>> -	 */
>> -	if (fsopt->flags & CEPH_MOUNT_OPT_TEST_DUMMY_ENC) {
>> -		struct ceph_fs_client *fsc = sb->s_fs_info;
>> -		int err = 0;
>> +	struct ceph_fs_client *fsc = sb->s_fs_info;
>> +	int err;
>>   
>> -		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE && !fsc->dummy_enc_policy.policy) {
>> -			errorfc(fc, "Can't set test_dummy_encryption on remount");
>> -			return -EEXIST;
>> -		}
>> +	if (!fscrypt_is_dummy_policy_set(&fsopt->dummy_enc_policy))
>> +		return 0;
>>   
>> -		err = fscrypt_set_test_dummy_encryption(sb,
>> -							fsc->mount_options->test_dummy_encryption,
>> -							&fsc->dummy_enc_policy);
>> -		if (err) {
>> -			if (err == -EEXIST)
>> -				errorfc(fc, "Can't change test_dummy_encryption on remount");
>> -			else if (err == -EINVAL)
>> -				errorfc(fc, "Value of option \"%s\" is unrecognized",
>> -					fsc->mount_options->test_dummy_encryption);
>> -			else
>> -				errorfc(fc, "Error processing option \"%s\" [%d]",
>> -					fsc->mount_options->test_dummy_encryption, err);
>> -			return err;
>> -		}
>> -		warnfc(fc, "test_dummy_encryption mode enabled");
>> +	/* No changing encryption context on remount. */
>> +	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE &&
>> +	    !fscrypt_is_dummy_policy_set(&fsc->fsc_dummy_enc_policy)) {
>> +		if (fscrypt_dummy_policies_equal(&fsopt->dummy_enc_policy,
>> +						 &fsc->fsc_dummy_enc_policy))
>> +			return 0;
>> +		errorfc(fc, "Can't set test_dummy_encryption on remount");
>> +		return -EINVAL;
>>   	}
>> +
>> +	/* Also make sure fsopt doesn't contain a conflicting value. */
>> +	if (fscrypt_is_dummy_policy_set(&fsc->fsc_dummy_enc_policy)) {
>> +		if (fscrypt_dummy_policies_equal(&fsopt->dummy_enc_policy,
>> +						 &fsc->fsc_dummy_enc_policy))
>> +			return 0;
>> +		errorfc(fc, "Conflicting test_dummy_encryption options");
>> +		return -EINVAL;
>> +	}
>> +
>> +	fsc->fsc_dummy_enc_policy = fsopt->dummy_enc_policy;
>> +	memset(&fsopt->dummy_enc_policy, 0, sizeof(fsopt->dummy_enc_policy));
>> +
>> +	err = fscrypt_add_test_dummy_key(sb, &fsc->fsc_dummy_enc_policy);
>> +	if (err) {
>> +		errorfc(fc, "Error adding test dummy encryption key, %d", err);
>> +		return err;
>> +	}
>> +
>> +	warnfc(fc, "test_dummy_encryption mode enabled");
>>   	return 0;
>>   }
>> -#else
>> -static inline int ceph_set_test_dummy_encryption(struct super_block *sb, struct fs_context *fc,
>> -						struct ceph_mount_options *fsopt)
>> -{
>> -	if (fsopt->flags & CEPH_MOUNT_OPT_TEST_DUMMY_ENC)
>> -		warnfc(fc, "test_dummy_encryption mode ignored");
>> -	return 0;
>> -}
>> -#endif
>>   
>>   /*
>>    * mount: join the ceph cluster, and open root directory.
>> @@ -1154,7 +1156,7 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
>>   				goto out;
>>   		}
>>   
>> -		err = ceph_set_test_dummy_encryption(fsc->sb, fc, fsc->mount_options);
>> +		err = ceph_apply_test_dummy_encryption(fsc->sb, fc, fsc->mount_options);
>>   		if (err)
>>   			goto out;
>>   
>> @@ -1373,7 +1375,7 @@ static int ceph_reconfigure_fc(struct fs_context *fc)
>>   	struct super_block *sb = fc->root->d_sb;
>>   	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
>>   
>> -	err = ceph_set_test_dummy_encryption(sb, fc, fsopt);
>> +	err = ceph_apply_test_dummy_encryption(sb, fc, fsopt);
>>   	if (err)
>>   		return err;
>>   
>> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
>> index bfc8bfcea799..5ea0ac6450dd 100644
>> --- a/fs/ceph/super.h
>> +++ b/fs/ceph/super.h
>> @@ -44,7 +44,6 @@
>>   #define CEPH_MOUNT_OPT_ASYNC_DIROPS    (1<<15) /* allow async directory ops */
>>   #define CEPH_MOUNT_OPT_NOPAGECACHE     (1<<16) /* bypass pagecache altogether */
>>   #define CEPH_MOUNT_OPT_SPARSEREAD      (1<<17) /* always do sparse reads */
>> -#define CEPH_MOUNT_OPT_TEST_DUMMY_ENC  (1<<18) /* enable dummy encryption (for testing) */
>>   
>>   #define CEPH_MOUNT_OPT_DEFAULT			\
>>   	(CEPH_MOUNT_OPT_DCACHE |		\
>> @@ -101,7 +100,7 @@ struct ceph_mount_options {
>>   	char *server_path;    /* default NULL (means "/") */
>>   	char *fscache_uniq;   /* default NULL */
>>   	char *mon_addr;
>> -	char *test_dummy_encryption;	/* default NULL */
>> +	struct fscrypt_dummy_policy dummy_enc_policy;
>>   };
>>   
>>   #define CEPH_ASYNC_CREATE_CONFLICT_BITS 8
>> @@ -148,7 +147,7 @@ struct ceph_fs_client {
>>   	struct fscache_volume *fscache;
>>   #endif
>>   #ifdef CONFIG_FS_ENCRYPTION
>> -	struct fscrypt_dummy_policy dummy_enc_policy;
>> +	struct fscrypt_dummy_policy fsc_dummy_enc_policy;
>>   #endif
>>   };
>>   
> LGTM
>
> Reviewed-by: Jeff Layton <jlayton@kernel.org>

Thanks Jeff.

I will fold this into the previous commit.

-- Xiubo