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

[Jeff Layton <jlayton@kernel.org>]

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>