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

From: Jeff Layton <jlayton@kernel.org>
To: idryomov@gmail.com, xiubli@redhat.com
Cc: ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-fscrypt@vger.kernel.org, linux-kernel@vger.kernel.org,
	lhenriques@suse.de
Subject: [RFC PATCH v11 09/51] ceph: add ability to set fscrypt_auth via setattr
Date: Tue, 22 Mar 2022 10:12:34 -0400	[thread overview]
Message-ID: <20220322141316.41325-10-jlayton@kernel.org> (raw)
In-Reply-To: <20220322141316.41325-1-jlayton@kernel.org>

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

