[RFC PATCH v11 10/51] ceph: implement -o test_dummy_encryption mount option

Jeff Layton
2022-03-22T14:14:23Z

Add support for the test_dummy_encryption mount option. This allows us
to test the encrypted codepaths in ceph without having to manually set
keys, etc.

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 | 80 ++++++++++++++++++++++++++++++++++++++++++++++--
fs/ceph/super.h | 12 +++++++-
fs/ceph/xattr.c | 3 ++
6 files changed, 178 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;
+
+ 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 c52625f4b5f4..9043761bd9c8 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 52ff78f0462a..6a2044d61420 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -47,6 +47,7 @@ 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);
}

@@ -150,6 +151,7 @@ enum {
Opt_recover_session,
Opt_source,
Opt_mon_addr,
+ Opt_test_dummy_encryption,
/* string args above */
Opt_dirstat,
Opt_rbytes,
@@ -192,6 +194,7 @@ 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),
@@ -203,7 +206,8 @@ 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),
@@ -583,6 +587,17 @@ static int ceph_parse_mount_param(struct fs_context *fc,
else
fsopt->flags |= CEPH_MOUNT_OPT_SPARSEREAD;
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();
}
@@ -603,6 +618,7 @@ 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);
}

@@ -722,6 +738,8 @@ static int ceph_show_options(struct seq_file *m, struct dentry *root)
if (fsopt->flags & CEPH_MOUNT_OPT_SPARSEREAD)
seq_puts(m, ",sparseread");

+ 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)
@@ -1056,6 +1074,52 @@ 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.
*/
@@ -1084,6 +1148,10 @@ 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);
@@ -1292,9 +1360,15 @@ 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);
@@ -1313,7 +1387,7 @@ 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 b05ae8899a1a..8f5fdb59344c 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"
+
/* large granularity for statfs utilization stats to facilitate
* large volume sizes on 32-bit machines. */
#define CEPH_BLOCK_SHIFT 22 /* 4 MB */
@@ -44,6 +47,7 @@
#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 | \
@@ -107,6 +111,7 @@ 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 {
@@ -146,9 +151,11 @@ 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
@@ -1091,6 +1098,9 @@ 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 8c2dc2c762a4..58628cef4207 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -1397,6 +1397,9 @@ 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);
--
2.35.1