ceph: fscrypt_auth handling for ceph

Most fscrypt-enabled filesystems store the crypto context in an xattr,
but that's problematic for ceph as xatts are governed by the XATTR cap,
but we really want the crypto context as part of the AUTH cap.

Because of this, the MDS has added two new inode metadata fields:
fscrypt_auth and fscrypt_file. The former is used to hold the crypto
context, and the latter is used to track the real file size.

Parse new fscrypt_auth and fscrypt_file fields in inode traces. For now,
we don't use fscrypt_file, but fscrypt_auth is used to hold the fscrypt
context.

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.

Have the set_context op do a setattr that sets the fscrypt_auth value,
and get_context just return the contents of that field (since it should
always be available).

Signed-off-by: Jeff Layton <[e-mail]>
Reviewed-by: Xiubo Li <[e-mail]>
Reviewed-and-tested-by: Luís Henriques <[e-mail]>
Reviewed-by: Milind Changire <[e-mail]>
Signed-off-by: Ilya Dryomov <[e-mail]>

fs/ceph/Makefile

···
 
 ceph-$(CONFIG_CEPH_FSCACHE) += cache.o
 ceph-$(CONFIG_CEPH_FS_POSIX_ACL) += acl.o
+ceph-$(CONFIG_FS_ENCRYPTION) += crypto.o

fs/ceph/acl.c

···
 		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;
 	}
···
 			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;
 	}

fs/ceph/caps.c

···
 #include "super.h"
 #include "mds_client.h"
 #include "cache.h"
+#include "crypto.h"
 #include <linux/ceph/decode.h>
 #include <linux/ceph/messenger.h>
 
···
 	umode_t			mode;
 	bool			inline_data;
 	bool			wake;
+	u32			fscrypt_auth_len;
+	u32			fscrypt_file_len;
+	u8			fscrypt_auth[sizeof(struct ceph_fscrypt_auth)]; // for context
+	u8			fscrypt_file[sizeof(u64)]; // for size
 };
-
-/*
- * cap struct size + flock buffer size + inline version + inline data size +
- * osd_epoch_barrier + oldest_flush_tid
- */
-#define CAP_MSG_SIZE (sizeof(struct ceph_mds_caps) + \
-		      4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4)
 
 /* Marshal up the cap msg to the MDS */
 static void encode_cap_msg(struct ceph_msg *msg, struct cap_msg_args *arg)
···
 	     arg->size, arg->max_size, arg->xattr_version,
 	     arg->xattr_buf ? (int)arg->xattr_buf->vec.iov_len : 0);
 
-	msg->hdr.version = cpu_to_le16(10);
+	msg->hdr.version = cpu_to_le16(12);
 	msg->hdr.tid = cpu_to_le64(arg->flush_tid);
 
 	fc = msg->front.iov_base;
···
 
 	/* Advisory flags (version 10) */
 	ceph_encode_32(&p, arg->flags);
+
+	/* dirstats (version 11) - these are r/o on the client */
+	ceph_encode_64(&p, 0);
+	ceph_encode_64(&p, 0);
+
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+	/* fscrypt_auth and fscrypt_file (version 12) */
+	ceph_encode_32(&p, arg->fscrypt_auth_len);
+	ceph_encode_copy(&p, arg->fscrypt_auth, arg->fscrypt_auth_len);
+	ceph_encode_32(&p, arg->fscrypt_file_len);
+	ceph_encode_copy(&p, arg->fscrypt_file, arg->fscrypt_file_len);
+#else /* CONFIG_FS_ENCRYPTION */
+	ceph_encode_32(&p, 0);
+	ceph_encode_32(&p, 0);
+#endif /* CONFIG_FS_ENCRYPTION */
 }
 
 /*
···
 		}
 	}
 	arg->flags = flags;
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+	if (ci->fscrypt_auth_len &&
+	    WARN_ON_ONCE(ci->fscrypt_auth_len > sizeof(struct ceph_fscrypt_auth))) {
+		/* Don't set this if it's too big */
+		arg->fscrypt_auth_len = 0;
+	} else {
+		arg->fscrypt_auth_len = ci->fscrypt_auth_len;
+		memcpy(arg->fscrypt_auth, ci->fscrypt_auth,
+		       min_t(size_t, ci->fscrypt_auth_len,
+			     sizeof(arg->fscrypt_auth)));
+	}
+	/* FIXME: use this to track "real" size */
+	arg->fscrypt_file_len = 0;
+#endif /* CONFIG_FS_ENCRYPTION */
 }
+
+#define CAP_MSG_FIXED_FIELDS (sizeof(struct ceph_mds_caps) + \
+		      4 + 8 + 4 + 4 + 8 + 4 + 4 + 4 + 8 + 8 + 4 + 8 + 8 + 4 + 4)
+
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+static inline int cap_msg_size(struct cap_msg_args *arg)
+{
+	return CAP_MSG_FIXED_FIELDS + arg->fscrypt_auth_len +
+			arg->fscrypt_file_len;
+}
+#else
+static inline int cap_msg_size(struct cap_msg_args *arg)
+{
+	return CAP_MSG_FIXED_FIELDS;
+}
+#endif /* CONFIG_FS_ENCRYPTION */
 
 /*
  * Send a cap msg on the given inode.
···
 	struct ceph_msg *msg;
 	struct inode *inode = &ci->netfs.inode;
 
-	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, CAP_MSG_SIZE, GFP_NOFS, false);
+	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, cap_msg_size(arg), GFP_NOFS,
+			   false);
 	if (!msg) {
 		pr_err("error allocating cap msg: ino (%llx.%llx) flushing %s tid %llu, requeuing cap.\n",
 		       ceph_vinop(inode), ceph_cap_string(arg->dirty),
···
 {
 	struct cap_msg_args	arg;
 	struct ceph_msg		*msg;
-
-	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, CAP_MSG_SIZE, GFP_NOFS, false);
-	if (!msg)
-		return -ENOMEM;
 
 	arg.session = session;
 	arg.ino = ceph_vino(inode).ino;
···
 	arg.inline_data = capsnap->inline_data;
 	arg.flags = 0;
 	arg.wake = false;
+
+	/*
+	 * No fscrypt_auth changes from a capsnap. It will need
+	 * to update fscrypt_file on size changes (TODO).
+	 */
+	arg.fscrypt_auth_len = 0;
+	arg.fscrypt_file_len = 0;
+
+	msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, cap_msg_size(&arg),
+			   GFP_NOFS, false);
+	if (!msg)
+		return -ENOMEM;
 
 	encode_cap_msg(msg, &arg);
 	ceph_con_send(&arg.session->s_con, msg);

fs/ceph/crypto.c

···
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/ceph/ceph_debug.h>
+#include <linux/xattr.h>
+#include <linux/fscrypt.h>
+
+#include "super.h"
+#include "crypto.h"
+
+static int ceph_crypt_get_context(struct inode *inode, void *ctx, size_t len)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+	struct ceph_fscrypt_auth *cfa = (struct ceph_fscrypt_auth *)ci->fscrypt_auth;
+	u32 ctxlen;
+
+	/* Non existent or too short? */
+	if (!cfa || (ci->fscrypt_auth_len < (offsetof(struct ceph_fscrypt_auth, cfa_blob) + 1)))
+		return -ENOBUFS;
+
+	/* Some format we don't recognize? */
+	if (le32_to_cpu(cfa->cfa_version) != CEPH_FSCRYPT_AUTH_VERSION)
+		return -ENOBUFS;
+
+	ctxlen = le32_to_cpu(cfa->cfa_blob_len);
+	if (len < ctxlen)
+		return -ERANGE;
+
+	memcpy(ctx, cfa->cfa_blob, ctxlen);
+	return ctxlen;
+}
+
+static int ceph_crypt_set_context(struct inode *inode, const void *ctx,
+				  size_t len, void *fs_data)
+{
+	int ret;
+	struct iattr attr = { };
+	struct ceph_iattr cia = { };
+	struct ceph_fscrypt_auth *cfa;
+
+	WARN_ON_ONCE(fs_data);
+
+	if (len > FSCRYPT_SET_CONTEXT_MAX_SIZE)
+		return -EINVAL;
+
+	cfa = kzalloc(sizeof(*cfa), GFP_KERNEL);
+	if (!cfa)
+		return -ENOMEM;
+
+	cfa->cfa_version = cpu_to_le32(CEPH_FSCRYPT_AUTH_VERSION);
+	cfa->cfa_blob_len = cpu_to_le32(len);
+	memcpy(cfa->cfa_blob, ctx, len);
+
+	cia.fscrypt_auth = cfa;
+
+	ret = __ceph_setattr(inode, &attr, &cia);
+	if (ret == 0)
+		inode_set_flags(inode, S_ENCRYPTED, S_ENCRYPTED);
+	kfree(cia.fscrypt_auth);
+	return ret;
+}
+
+static bool ceph_crypt_empty_dir(struct inode *inode)
+{
+	struct ceph_inode_info *ci = ceph_inode(inode);
+
+	return ci->i_rsubdirs + ci->i_rfiles == 1;
+}
+
+static struct fscrypt_operations ceph_fscrypt_ops = {
+	.get_context		= ceph_crypt_get_context,
+	.set_context		= ceph_crypt_set_context,
+	.empty_dir		= ceph_crypt_empty_dir,
+};
+
+void ceph_fscrypt_set_ops(struct super_block *sb)
+{
+	fscrypt_set_ops(sb, &ceph_fscrypt_ops);
+}

fs/ceph/crypto.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Ceph fscrypt functionality
+ */
+
+#ifndef _CEPH_CRYPTO_H
+#define _CEPH_CRYPTO_H
+
+#include <linux/fscrypt.h>
+
+struct ceph_fscrypt_auth {
+	__le32	cfa_version;
+	__le32	cfa_blob_len;
+	u8	cfa_blob[FSCRYPT_SET_CONTEXT_MAX_SIZE];
+} __packed;
+
+#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 */
+
+static inline void ceph_fscrypt_set_ops(struct super_block *sb)
+{
+}
+
+#endif /* CONFIG_FS_ENCRYPTION */
+
+#endif

fs/ceph/inode.c

···
 #include <linux/random.h>
 #include <linux/sort.h>
 #include <linux/iversion.h>
+#include <linux/fscrypt.h>
 
 #include "super.h"
 #include "mds_client.h"
 #include "cache.h"
+#include "crypto.h"
 #include <linux/ceph/decode.h>
 
 /*
···
 	INIT_WORK(&ci->i_work, ceph_inode_work);
 	ci->i_work_mask = 0;
 	memset(&ci->i_btime, '\0', sizeof(ci->i_btime));
+#ifdef CONFIG_FS_ENCRYPTION
+	ci->fscrypt_auth = NULL;
+	ci->fscrypt_auth_len = 0;
+#endif
 	return &ci->netfs.inode;
 }
 
···
 	struct ceph_inode_info *ci = ceph_inode(inode);
 
 	kfree(ci->i_symlink);
+#ifdef CONFIG_FS_ENCRYPTION
+	kfree(ci->fscrypt_auth);
+#endif
 	kmem_cache_free(ceph_inode_cachep, ci);
 }
 
···
 	clear_inode(inode);
 
 	ceph_fscache_unregister_inode_cookie(ci);
+	fscrypt_put_encryption_info(inode);
 
 	__ceph_remove_caps(ci);
 
···
 		inode->i_blkbits = CEPH_BLOCK_SHIFT;
 
 	__ceph_update_quota(ci, iinfo->max_bytes, iinfo->max_files);
+
+#ifdef CONFIG_FS_ENCRYPTION
+	if (iinfo->fscrypt_auth_len && (inode->i_state & I_NEW)) {
+		kfree(ci->fscrypt_auth);
+		ci->fscrypt_auth_len = iinfo->fscrypt_auth_len;
+		ci->fscrypt_auth = iinfo->fscrypt_auth;
+		iinfo->fscrypt_auth = NULL;
+		iinfo->fscrypt_auth_len = 0;
+		inode_set_flags(inode, S_ENCRYPTED, S_ENCRYPTED);
+	}
+#endif
 
 	if ((new_version || (new_issued & CEPH_CAP_AUTH_SHARED)) &&
 	    (issued & CEPH_CAP_AUTH_EXCL) == 0) {
···
 	.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;
···
 	}
 
 	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,
···
 		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);
 
···
 	    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(&nop_mnt_idmap, dentry, attr->ia_mode);

fs/ceph/mds_client.c

···
 
 #include "super.h"
 #include "mds_client.h"
+#include "crypto.h"
 
 #include <linux/ceph/ceph_features.h>
 #include <linux/ceph/messenger.h>
···
 			info->rsnaps = 0;
 		}
 
+		if (struct_v >= 5) {
+			u32 alen;
+
+			ceph_decode_32_safe(p, end, alen, bad);
+
+			while (alen--) {
+				u32 len;
+
+				/* key */
+				ceph_decode_32_safe(p, end, len, bad);
+				ceph_decode_skip_n(p, end, len, bad);
+				/* value */
+				ceph_decode_32_safe(p, end, len, bad);
+				ceph_decode_skip_n(p, end, len, bad);
+			}
+		}
+
+		/* fscrypt flag -- ignore */
+		if (struct_v >= 6)
+			ceph_decode_skip_8(p, end, bad);
+
+		info->fscrypt_auth = NULL;
+		info->fscrypt_auth_len = 0;
+		info->fscrypt_file = NULL;
+		info->fscrypt_file_len = 0;
+		if (struct_v >= 7) {
+			ceph_decode_32_safe(p, end, info->fscrypt_auth_len, bad);
+			if (info->fscrypt_auth_len) {
+				info->fscrypt_auth = kmalloc(info->fscrypt_auth_len,
+							     GFP_KERNEL);
+				if (!info->fscrypt_auth)
+					return -ENOMEM;
+				ceph_decode_copy_safe(p, end, info->fscrypt_auth,
+						      info->fscrypt_auth_len, bad);
+			}
+			ceph_decode_32_safe(p, end, info->fscrypt_file_len, bad);
+			if (info->fscrypt_file_len) {
+				info->fscrypt_file = kmalloc(info->fscrypt_file_len,
+							     GFP_KERNEL);
+				if (!info->fscrypt_file)
+					return -ENOMEM;
+				ceph_decode_copy_safe(p, end, info->fscrypt_file,
+						      info->fscrypt_file_len, bad);
+			}
+		}
 		*p = end;
 	} else {
+		/* legacy (unversioned) struct */
 		if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
 			ceph_decode_64_safe(p, end, info->inline_version, bad);
 			ceph_decode_32_safe(p, end, info->inline_len, bad);
···
 
 static void destroy_reply_info(struct ceph_mds_reply_info_parsed *info)
 {
+	int i;
+
+	kfree(info->diri.fscrypt_auth);
+	kfree(info->diri.fscrypt_file);
+	kfree(info->targeti.fscrypt_auth);
+	kfree(info->targeti.fscrypt_file);
 	if (!info->dir_entries)
 		return;
+
+	for (i = 0; i < info->dir_nr; i++) {
+		struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
+
+		kfree(rde->inode.fscrypt_auth);
+		kfree(rde->inode.fscrypt_file);
+	}
 	free_pages((unsigned long)info->dir_entries, get_order(info->dir_buf_size));
 }
 
···
 	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));
···
 	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;
···
 	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
 }
 
 /*
···
 		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);
···
 		len += pathlen1;
 	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) {
···
 	} 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);
···
 
 	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);
···
 		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);

fs/ceph/mds_client.h

···
 	s32 dir_pin;
 	struct ceph_timespec btime;
 	struct ceph_timespec snap_btime;
+	u8 *fscrypt_auth;
+	u8 *fscrypt_file;
+	u32 fscrypt_auth_len;
+	u32 fscrypt_file_len;
 	u64 rsnaps;
 	u64 change_attr;
 };
···
 	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;

fs/ceph/super.c

···
 #include "super.h"
 #include "mds_client.h"
 #include "cache.h"
+#include "crypto.h"
 
 #include <linux/ceph/ceph_features.h>
 #include <linux/ceph/decode.h>
···
 	s->s_time_min = 0;
 	s->s_time_max = U32_MAX;
 	s->s_flags |= SB_NODIRATIME | SB_NOATIME;
+
+	ceph_fscrypt_set_ops(s);
 
 	ret = set_anon_super_fc(s, fc);
 	if (ret != 0)

fs/ceph/super.h

···
 
 	struct work_struct i_work;
 	unsigned long  i_work_mask;
+
+#ifdef CONFIG_FS_ENCRYPTION
+	u32 fscrypt_auth_len;
+	u32 fscrypt_file_len;
+	u8 *fscrypt_auth;
+	u8 *fscrypt_file;
+#endif
 };
 
 struct ceph_netfs_request_data {
···
 }
 extern int ceph_permission(struct mnt_idmap *idmap,
 			   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 mnt_idmap *idmap,
 			struct dentry *dentry, struct iattr *attr);
 extern int ceph_getattr(struct mnt_idmap *idmap,

include/linux/ceph/ceph_fs.h

···
 
 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.