Re: [RFC PATCH v10 10/48] ceph: implement -o test_dummy_encryption mount option

["Luís Henriques" <lhenriques@suse.de>]

Jeff Layton <jlayton@kernel.org> writes:

> Signed-off-by: Jeff Layton <jlayton@kernel.org>
> ---
>  fs/ceph/crypto.c | 53 ++++++++++++++++++++++++++++++++
>  fs/ceph/crypto.h | 26 ++++++++++++++++
>  fs/ceph/inode.c  | 10 ++++--
>  fs/ceph/super.c  | 79 ++++++++++++++++++++++++++++++++++++++++++++++--
>  fs/ceph/super.h  | 12 +++++++-
>  fs/ceph/xattr.c  |  3 ++
>  6 files changed, 177 insertions(+), 6 deletions(-)
>
> diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c
> index a513ff373b13..017f31eacb74 100644
> --- a/fs/ceph/crypto.c
> +++ b/fs/ceph/crypto.c
> @@ -4,6 +4,7 @@
>  #include <linux/fscrypt.h>
>  
>  #include "super.h"
> +#include "mds_client.h"
>  #include "crypto.h"
>  
>  static int ceph_crypt_get_context(struct inode *inode, void *ctx, size_t len)
> @@ -64,9 +65,20 @@ static bool ceph_crypt_empty_dir(struct inode *inode)
>  	return ci->i_rsubdirs + ci->i_rfiles == 1;
>  }
>  
> +void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc)
> +{
> +	fscrypt_free_dummy_policy(&fsc->dummy_enc_policy);
> +}
> +
> +static const union fscrypt_policy *ceph_get_dummy_policy(struct super_block *sb)
> +{
> +	return ceph_sb_to_client(sb)->dummy_enc_policy.policy;
> +}
> +
>  static struct fscrypt_operations ceph_fscrypt_ops = {
>  	.get_context		= ceph_crypt_get_context,
>  	.set_context		= ceph_crypt_set_context,
> +	.get_dummy_policy	= ceph_get_dummy_policy,
>  	.empty_dir		= ceph_crypt_empty_dir,
>  };
>  
> @@ -74,3 +86,44 @@ void ceph_fscrypt_set_ops(struct super_block *sb)
>  {
>  	fscrypt_set_ops(sb, &ceph_fscrypt_ops);
>  }
> +
> +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
> +				 struct ceph_acl_sec_ctx *as)
> +{
> +	int ret, ctxsize;
> +	bool encrypted = false;
> +	struct ceph_inode_info *ci = ceph_inode(inode);
> +
> +	ret = fscrypt_prepare_new_inode(dir, inode, &encrypted);
> +	if (ret)
> +		return ret;
> +	if (!encrypted)
> +		return 0;
> +
> +	as->fscrypt_auth = kzalloc(sizeof(*as->fscrypt_auth), GFP_KERNEL);
> +	if (!as->fscrypt_auth)
> +		return -ENOMEM;
> +

Isn't this memory allocation leaking bellow in the error paths?

(Yeah, I'm finally (but slowly) catching up with this series... my memory
is blurry and there are a lot of things I forgot...)

Cheers,
-- 
Luís

> +	ctxsize = fscrypt_context_for_new_inode(as->fscrypt_auth->cfa_blob, inode);
> +	if (ctxsize < 0)
> +		return ctxsize;
> +
> +	as->fscrypt_auth->cfa_version = cpu_to_le32(CEPH_FSCRYPT_AUTH_VERSION);
> +	as->fscrypt_auth->cfa_blob_len = cpu_to_le32(ctxsize);
> +
> +	WARN_ON_ONCE(ci->fscrypt_auth);
> +	kfree(ci->fscrypt_auth);
> +	ci->fscrypt_auth_len = ceph_fscrypt_auth_len(as->fscrypt_auth);
> +	ci->fscrypt_auth = kmemdup(as->fscrypt_auth, ci->fscrypt_auth_len, GFP_KERNEL);
> +	if (!ci->fscrypt_auth)
> +		return -ENOMEM;
> +
> +	inode->i_flags |= S_ENCRYPTED;
> +
> +	return 0;
> +}
> +
> +void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as)
> +{
> +	swap(req->r_fscrypt_auth, as->fscrypt_auth);
> +}
> diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
> index 6dca674f79b8..cb00fe42d5b7 100644
> --- a/fs/ceph/crypto.h
> +++ b/fs/ceph/crypto.h
> @@ -8,6 +8,10 @@
>  
>  #include <linux/fscrypt.h>
>  
> +struct ceph_fs_client;
> +struct ceph_acl_sec_ctx;
> +struct ceph_mds_request;
> +
>  struct ceph_fscrypt_auth {
>  	__le32	cfa_version;
>  	__le32	cfa_blob_len;
> @@ -25,12 +29,34 @@ static inline u32 ceph_fscrypt_auth_len(struct ceph_fscrypt_auth *fa)
>  #ifdef CONFIG_FS_ENCRYPTION
>  void ceph_fscrypt_set_ops(struct super_block *sb);
>  
> +void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc);
> +
> +int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
> +				 struct ceph_acl_sec_ctx *as);
> +void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *as);
> +
>  #else /* CONFIG_FS_ENCRYPTION */
>  
>  static inline void ceph_fscrypt_set_ops(struct super_block *sb)
>  {
>  }
>  
> +static inline void ceph_fscrypt_free_dummy_policy(struct ceph_fs_client *fsc)
> +{
> +}
> +
> +static inline int ceph_fscrypt_prepare_context(struct inode *dir, struct inode *inode,
> +						struct ceph_acl_sec_ctx *as)
> +{
> +	if (IS_ENCRYPTED(dir))
> +		return -EOPNOTSUPP;
> +	return 0;
> +}
> +
> +static inline void ceph_fscrypt_as_ctx_to_req(struct ceph_mds_request *req,
> +						struct ceph_acl_sec_ctx *as_ctx)
> +{
> +}
>  #endif /* CONFIG_FS_ENCRYPTION */
>  
>  #endif
> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> index c6653f83b6f0..55e23e2601df 100644
> --- a/fs/ceph/inode.c
> +++ b/fs/ceph/inode.c
> @@ -83,12 +83,17 @@ struct inode *ceph_new_inode(struct inode *dir, struct dentry *dentry,
>  			goto out_err;
>  	}
>  
> +	inode->i_state = 0;
> +	inode->i_mode = *mode;
> +
>  	err = ceph_security_init_secctx(dentry, *mode, as_ctx);
>  	if (err < 0)
>  		goto out_err;
>  
> -	inode->i_state = 0;
> -	inode->i_mode = *mode;
> +	err = ceph_fscrypt_prepare_context(dir, inode, as_ctx);
> +	if (err)
> +		goto out_err;
> +
>  	return inode;
>  out_err:
>  	iput(inode);
> @@ -101,6 +106,7 @@ void ceph_as_ctx_to_req(struct ceph_mds_request *req, struct ceph_acl_sec_ctx *a
>  		req->r_pagelist = as_ctx->pagelist;
>  		as_ctx->pagelist = NULL;
>  	}
> +	ceph_fscrypt_as_ctx_to_req(req, as_ctx);
>  }
>  
>  /**
> diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> index fbdf434b4618..0b32d31c6fe0 100644
> --- a/fs/ceph/super.c
> +++ b/fs/ceph/super.c
> @@ -45,6 +45,7 @@ static void ceph_put_super(struct super_block *s)
>  	struct ceph_fs_client *fsc = ceph_sb_to_client(s);
>  
>  	dout("put_super\n");
> +	ceph_fscrypt_free_dummy_policy(fsc);
>  	ceph_mdsc_close_sessions(fsc->mdsc);
>  }
>  
> @@ -162,6 +163,7 @@ enum {
>  	Opt_copyfrom,
>  	Opt_wsync,
>  	Opt_pagecache,
> +	Opt_test_dummy_encryption,
>  };
>  
>  enum ceph_recover_session_mode {
> @@ -189,6 +191,7 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = {
>  	fsparam_string	("fsc",				Opt_fscache), // fsc=...
>  	fsparam_flag_no ("ino32",			Opt_ino32),
>  	fsparam_string	("mds_namespace",		Opt_mds_namespace),
> +	fsparam_string	("mon_addr",			Opt_mon_addr),
>  	fsparam_flag_no ("poolperm",			Opt_poolperm),
>  	fsparam_flag_no ("quotadf",			Opt_quotadf),
>  	fsparam_u32	("rasize",			Opt_rasize),
> @@ -200,7 +203,8 @@ static const struct fs_parameter_spec ceph_mount_parameters[] = {
>  	fsparam_u32	("rsize",			Opt_rsize),
>  	fsparam_string	("snapdirname",			Opt_snapdirname),
>  	fsparam_string	("source",			Opt_source),
> -	fsparam_string	("mon_addr",			Opt_mon_addr),
> +	fsparam_flag	("test_dummy_encryption",	Opt_test_dummy_encryption),
> +	fsparam_string	("test_dummy_encryption",	Opt_test_dummy_encryption),
>  	fsparam_u32	("wsize",			Opt_wsize),
>  	fsparam_flag_no	("wsync",			Opt_wsync),
>  	fsparam_flag_no	("pagecache",			Opt_pagecache),
> @@ -576,6 +580,16 @@ static int ceph_parse_mount_param(struct fs_context *fc,
>  		else
>  			fsopt->flags &= ~CEPH_MOUNT_OPT_NOPAGECACHE;
>  		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;
> +#else
> +		warnfc(fc, "FS encryption not supported: test_dummy_encryption mount option ignored");
> +#endif
> +		break;
>  	default:
>  		BUG();
>  	}
> @@ -596,6 +610,7 @@ 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);
>  	kfree(args);
>  }
>  
> @@ -714,6 +729,8 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
>  	if (fsopt->flags & CEPH_MOUNT_OPT_NOPAGECACHE)
>  		seq_puts(m, ",nopagecache");
>  
> +	fscrypt_show_test_dummy_encryption(m, ',', root->d_sb);
> +
>  	if (fsopt->wsize != CEPH_MAX_WRITE_SIZE)
>  		seq_printf(m, ",wsize=%u", fsopt->wsize);
>  	if (fsopt->rsize != CEPH_MAX_READ_SIZE)
> @@ -1041,6 +1058,52 @@ 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)
> +{
> +	/*
> +	 * 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;
> +
> +		if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE && !fsc->dummy_enc_policy.policy) {
> +			errorfc(fc, "Can't set test_dummy_encryption on remount");
> +			return -EEXIST;
> +		}
> +
> +		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");
> +	}
> +	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.
>   */
> @@ -1069,6 +1132,10 @@ 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);
> +		if (err)
> +			goto out;
> +
>  		dout("mount opening path '%s'\n", path);
>  
>  		ceph_fs_debugfs_init(fsc);
> @@ -1277,9 +1344,15 @@ static void ceph_free_fc(struct fs_context *fc)
>  
>  static int ceph_reconfigure_fc(struct fs_context *fc)
>  {
> +	int err;
>  	struct ceph_parse_opts_ctx *pctx = fc->fs_private;
>  	struct ceph_mount_options *fsopt = pctx->opts;
> -	struct ceph_fs_client *fsc = ceph_sb_to_client(fc->root->d_sb);
> +	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);
> +	if (err)
> +		return err;
>  
>  	if (fsopt->flags & CEPH_MOUNT_OPT_ASYNC_DIROPS)
>  		ceph_set_mount_opt(fsc, ASYNC_DIROPS);
> @@ -1293,7 +1366,7 @@ static int ceph_reconfigure_fc(struct fs_context *fc)
>  		pr_notice("ceph: monitor addresses recorded, but not used for reconnection");
>  	}
>  
> -	sync_filesystem(fc->root->d_sb);
> +	sync_filesystem(sb);
>  	return 0;
>  }
>  
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 853577f8d772..042ea1f8e5c2 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -17,6 +17,7 @@
>  #include <linux/posix_acl.h>
>  #include <linux/refcount.h>
>  #include <linux/security.h>
> +#include <linux/fscrypt.h>
>  
>  #include <linux/ceph/libceph.h>
>  
> @@ -24,6 +25,8 @@
>  #include <linux/fscache.h>
>  #endif
>  
> +#include "crypto.h"
> +
>  /* f_type in struct statfs */
>  #define CEPH_SUPER_MAGIC 0x00c36400
>  
> @@ -46,6 +49,7 @@
>  #define CEPH_MOUNT_OPT_NOCOPYFROM      (1<<14) /* don't use RADOS 'copy-from' op */
>  #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_TEST_DUMMY_ENC  (1<<17) /* enable dummy encryption (for testing) */
>  
>  #define CEPH_MOUNT_OPT_DEFAULT			\
>  	(CEPH_MOUNT_OPT_DCACHE |		\
> @@ -102,6 +106,7 @@ 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 ceph_fs_client {
> @@ -141,9 +146,11 @@ struct ceph_fs_client {
>  #ifdef CONFIG_CEPH_FSCACHE
>  	struct fscache_volume *fscache;
>  #endif
> +#ifdef CONFIG_FS_ENCRYPTION
> +	struct fscrypt_dummy_policy dummy_enc_policy;
> +#endif
>  };
>  
> -
>  /*
>   * File i/o capability.  This tracks shared state with the metadata
>   * server that allows us to cache or writeback attributes or to read
> @@ -1083,6 +1090,9 @@ struct ceph_acl_sec_ctx {
>  #ifdef CONFIG_CEPH_FS_SECURITY_LABEL
>  	void *sec_ctx;
>  	u32 sec_ctxlen;
> +#endif
> +#ifdef CONFIG_FS_ENCRYPTION
> +	struct ceph_fscrypt_auth *fscrypt_auth;
>  #endif
>  	struct ceph_pagelist *pagelist;
>  };
> diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
> index fcf7dfdecf96..5e3522457deb 100644
> --- a/fs/ceph/xattr.c
> +++ b/fs/ceph/xattr.c
> @@ -1380,6 +1380,9 @@ void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
>  #endif
>  #ifdef CONFIG_CEPH_FS_SECURITY_LABEL
>  	security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen);
> +#endif
> +#ifdef CONFIG_FS_ENCRYPTION
> +	kfree(as_ctx->fscrypt_auth);
>  #endif
>  	if (as_ctx->pagelist)
>  		ceph_pagelist_release(as_ctx->pagelist);
> -- 
>
> 2.34.1
>