[RFC PATCH v11 09/51] ceph: add ability to set fscrypt_auth via setattr

Jeff Layton
2022-03-22T14:17:55Z

Allow the client to use a setattr request for setting the fscrypt_auth
field. Since this is not a standard setattr request from the VFS, we add
a new field to __ceph_setattr that carries ceph-specific inode attrs.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/ceph/acl.c | 4 +--
fs/ceph/crypto.h | 9 +++++-
fs/ceph/inode.c | 42 ++++++++++++++++++++++++++--
fs/ceph/mds_client.c | 54 ++++++++++++++++++++++++++++++------
fs/ceph/mds_client.h | 3 ++
fs/ceph/super.h | 7 ++++-
include/linux/ceph/ceph_fs.h | 21 ++++++++------
7 files changed, 117 insertions(+), 23 deletions(-)

diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
index f4fc8e0b847c..427724c36316 100644
--- a/fs/ceph/acl.c
+++ b/fs/ceph/acl.c
@@ -139,7 +139,7 @@ int ceph_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
newattrs.ia_ctime = current_time(inode);
newattrs.ia_mode = new_mode;
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
- ret = __ceph_setattr(inode, &newattrs);
+ ret = __ceph_setattr(inode, &newattrs, NULL);
if (ret)
goto out_free;
}
@@ -150,7 +150,7 @@ int ceph_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
newattrs.ia_ctime = old_ctime;
newattrs.ia_mode = old_mode;
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
- __ceph_setattr(inode, &newattrs);
+ __ceph_setattr(inode, &newattrs, NULL);
}
goto out_free;
}
diff --git a/fs/ceph/crypto.h b/fs/ceph/crypto.h
index 6c3831c57c8d..6dca674f79b8 100644
--- a/fs/ceph/crypto.h
+++ b/fs/ceph/crypto.h
@@ -14,8 +14,15 @@ struct ceph_fscrypt_auth {
u8 cfa_blob[FSCRYPT_SET_CONTEXT_MAX_SIZE];
} __packed;

-#ifdef CONFIG_FS_ENCRYPTION
#define CEPH_FSCRYPT_AUTH_VERSION 1
+static inline u32 ceph_fscrypt_auth_len(struct ceph_fscrypt_auth *fa)
+{
+ u32 ctxsize = le32_to_cpu(fa->cfa_blob_len);
+
+ return offsetof(struct ceph_fscrypt_auth, cfa_blob) + ctxsize;
+}
+
+#ifdef CONFIG_FS_ENCRYPTION
void ceph_fscrypt_set_ops(struct super_block *sb);

#else /* CONFIG_FS_ENCRYPTION */
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 2c9a482444e0..c52625f4b5f4 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -2096,7 +2096,7 @@ static const struct inode_operations ceph_symlink_iops = {
.listxattr = ceph_listxattr,
};

-int __ceph_setattr(struct inode *inode, struct iattr *attr)
+int __ceph_setattr(struct inode *inode, struct iattr *attr, struct ceph_iattr *cia)
{
struct ceph_inode_info *ci = ceph_inode(inode);
unsigned int ia_valid = attr->ia_valid;
@@ -2136,6 +2136,43 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr)
}

dout("setattr %p issued %s\n", inode, ceph_cap_string(issued));
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+ if (cia && cia->fscrypt_auth) {
+ u32 len = ceph_fscrypt_auth_len(cia->fscrypt_auth);
+
+ if (len > sizeof(*cia->fscrypt_auth)) {
+ err = -EINVAL;
+ spin_unlock(&ci->i_ceph_lock);
+ goto out;
+ }
+
+ dout("setattr %llx:%llx fscrypt_auth len %u to %u)\n",
+ ceph_vinop(inode), ci->fscrypt_auth_len, len);
+
+ /* It should never be re-set once set */
+ WARN_ON_ONCE(ci->fscrypt_auth);
+
+ if (issued & CEPH_CAP_AUTH_EXCL) {
+ dirtied |= CEPH_CAP_AUTH_EXCL;
+ kfree(ci->fscrypt_auth);
+ ci->fscrypt_auth = (u8 *)cia->fscrypt_auth;
+ ci->fscrypt_auth_len = len;
+ } else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
+ ci->fscrypt_auth_len != len ||
+ memcmp(ci->fscrypt_auth, cia->fscrypt_auth, len)) {
+ req->r_fscrypt_auth = cia->fscrypt_auth;
+ mask |= CEPH_SETATTR_FSCRYPT_AUTH;
+ release |= CEPH_CAP_AUTH_SHARED;
+ }
+ cia->fscrypt_auth = NULL;
+ }
+#else
+ if (cia && cia->fscrypt_auth) {
+ err = -EINVAL;
+ spin_unlock(&ci->i_ceph_lock);
+ goto out;
+ }
+#endif /* CONFIG_FS_ENCRYPTION */

if (ia_valid & ATTR_UID) {
dout("setattr %p uid %d -> %d\n", inode,
@@ -2298,6 +2335,7 @@ int __ceph_setattr(struct inode *inode, struct iattr *attr)
req->r_stamp = attr->ia_ctime;
err = ceph_mdsc_do_request(mdsc, NULL, req);
}
+out:
dout("setattr %p result=%d (%s locally, %d remote)\n", inode, err,
ceph_cap_string(dirtied), mask);

@@ -2338,7 +2376,7 @@ int ceph_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
ceph_quota_is_max_bytes_exceeded(inode, attr->ia_size))
return -EDQUOT;

- err = __ceph_setattr(inode, attr);
+ err = __ceph_setattr(inode, attr, NULL);

if (err >= 0 && (attr->ia_valid & ATTR_MODE))
err = posix_acl_chmod(&init_user_ns, inode, attr->ia_mode);
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 8e7ef76d80ea..648816eb4228 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -15,6 +15,7 @@

#include "super.h"
#include "mds_client.h"
+#include "crypto.h"

#include <linux/ceph/ceph_features.h>
#include <linux/ceph/messenger.h>
@@ -946,6 +947,7 @@ void ceph_mdsc_release_request(struct kref *kref)
put_cred(req->r_cred);
if (req->r_pagelist)
ceph_pagelist_release(req->r_pagelist);
+ kfree(req->r_fscrypt_auth);
put_request_session(req);
ceph_unreserve_caps(req->r_mdsc, &req->r_caps_reservation);
WARN_ON_ONCE(!list_empty(&req->r_wait));
@@ -2526,8 +2528,7 @@ static int set_request_path_attr(struct inode *rinode, struct dentry *rdentry,
return r;
}

-static void encode_timestamp_and_gids(void **p,
- const struct ceph_mds_request *req)
+static void encode_mclientrequest_tail(void **p, const struct ceph_mds_request *req)
{
struct ceph_timespec ts;
int i;
@@ -2540,6 +2541,20 @@ static void encode_timestamp_and_gids(void **p,
for (i = 0; i < req->r_cred->group_info->ngroups; i++)
ceph_encode_64(p, from_kgid(&init_user_ns,
req->r_cred->group_info->gid[i]));
+
+ /* v5: altname (TODO: skip for now) */
+ ceph_encode_32(p, 0);
+
+ /* v6: fscrypt_auth and fscrypt_file */
+ if (req->r_fscrypt_auth) {
+ u32 authlen = ceph_fscrypt_auth_len(req->r_fscrypt_auth);
+
+ ceph_encode_32(p, authlen);
+ ceph_encode_copy(p, req->r_fscrypt_auth, authlen);
+ } else {
+ ceph_encode_32(p, 0);
+ }
+ ceph_encode_32(p, 0); // fscrypt_file for now
}

/*
@@ -2584,12 +2599,14 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
goto out_free1;
}

+ /* head */
len = legacy ? sizeof(*head) : sizeof(struct ceph_mds_request_head);
- len += pathlen1 + pathlen2 + 2*(1 + sizeof(u32) + sizeof(u64)) +
- sizeof(struct ceph_timespec);
- len += sizeof(u32) + (sizeof(u64) * req->r_cred->group_info->ngroups);

- /* calculate (max) length for cap releases */
+ /* filepaths */
+ len += 2 * (1 + sizeof(u32) + sizeof(u64));
+ len += pathlen1 + pathlen2;
+
+ /* cap releases */
len += sizeof(struct ceph_mds_request_release) *
(!!req->r_inode_drop + !!req->r_dentry_drop +
!!req->r_old_inode_drop + !!req->r_old_dentry_drop);
@@ -2599,6 +2616,25 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
if (req->r_old_dentry_drop)
len += pathlen2;

+ /* MClientRequest tail */
+
+ /* req->r_stamp */
+ len += sizeof(struct ceph_timespec);
+
+ /* gid list */
+ len += sizeof(u32) + (sizeof(u64) * req->r_cred->group_info->ngroups);
+
+ /* alternate name */
+ len += sizeof(u32); // TODO
+
+ /* fscrypt_auth */
+ len += sizeof(u32); // fscrypt_auth
+ if (req->r_fscrypt_auth)
+ len += ceph_fscrypt_auth_len(req->r_fscrypt_auth);
+
+ /* fscrypt_file */
+ len += sizeof(u32);
+
msg = ceph_msg_new2(CEPH_MSG_CLIENT_REQUEST, len, 1, GFP_NOFS, false);
if (!msg) {
msg = ERR_PTR(-ENOMEM);
@@ -2618,7 +2654,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,
} else {
struct ceph_mds_request_head *new_head = msg->front.iov_base;

- msg->hdr.version = cpu_to_le16(4);
+ msg->hdr.version = cpu_to_le16(6);
new_head->version = cpu_to_le16(CEPH_MDS_REQUEST_HEAD_VERSION);
head = (struct ceph_mds_request_head_old *)&new_head->oldest_client_tid;
p = msg->front.iov_base + sizeof(*new_head);
@@ -2669,7 +2705,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session,

head->num_releases = cpu_to_le16(releases);

- encode_timestamp_and_gids(&p, req);
+ encode_mclientrequest_tail(&p, req);

if (WARN_ON_ONCE(p > end)) {
ceph_msg_put(msg);
@@ -2778,7 +2814,7 @@ static int __prepare_send_request(struct ceph_mds_session *session,
rhead->num_releases = 0;

p = msg->front.iov_base + req->r_request_release_offset;
- encode_timestamp_and_gids(&p, req);
+ encode_mclientrequest_tail(&p, req);

msg->front.iov_len = p - msg->front.iov_base;
msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 96d726ee5250..aab3ab284fce 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -284,6 +284,9 @@ struct ceph_mds_request {
struct mutex r_fill_mutex;

union ceph_mds_request_args r_args;
+
+ struct ceph_fscrypt_auth *r_fscrypt_auth;
+
int r_fmode; /* file mode, if expecting cap */
int r_request_release_offset;
const struct cred *r_cred;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index e12e5b484564..b05ae8899a1a 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1052,7 +1052,12 @@ static inline int ceph_do_getattr(struct inode *inode, int mask, bool force)
}
extern int ceph_permission(struct user_namespace *mnt_userns,
struct inode *inode, int mask);
-extern int __ceph_setattr(struct inode *inode, struct iattr *attr);
+
+struct ceph_iattr {
+ struct ceph_fscrypt_auth *fscrypt_auth;
+};
+
+extern int __ceph_setattr(struct inode *inode, struct iattr *attr, struct ceph_iattr *cia);
extern int ceph_setattr(struct user_namespace *mnt_userns,
struct dentry *dentry, struct iattr *attr);
extern int ceph_getattr(struct user_namespace *mnt_userns,
diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
index 86bf82dbd8b8..2810b214fa3f 100644
--- a/include/linux/ceph/ceph_fs.h
+++ b/include/linux/ceph/ceph_fs.h
@@ -359,14 +359,19 @@ enum {

extern const char *ceph_mds_op_name(int op);

-
-#define CEPH_SETATTR_MODE 1
-#define CEPH_SETATTR_UID 2
-#define CEPH_SETATTR_GID 4
-#define CEPH_SETATTR_MTIME 8
-#define CEPH_SETATTR_ATIME 16
-#define CEPH_SETATTR_SIZE 32
-#define CEPH_SETATTR_CTIME 64
+#define CEPH_SETATTR_MODE (1 << 0)
+#define CEPH_SETATTR_UID (1 << 1)
+#define CEPH_SETATTR_GID (1 << 2)
+#define CEPH_SETATTR_MTIME (1 << 3)
+#define CEPH_SETATTR_ATIME (1 << 4)
+#define CEPH_SETATTR_SIZE (1 << 5)
+#define CEPH_SETATTR_CTIME (1 << 6)
+#define CEPH_SETATTR_MTIME_NOW (1 << 7)
+#define CEPH_SETATTR_ATIME_NOW (1 << 8)
+#define CEPH_SETATTR_BTIME (1 << 9)
+#define CEPH_SETATTR_KILL_SGUID (1 << 10)
+#define CEPH_SETATTR_FSCRYPT_AUTH (1 << 11)
+#define CEPH_SETATTR_FSCRYPT_FILE (1 << 12)

/*
* Ceph setxattr request flags.
--
2.35.1