Commit 60267ba3 authored by Ilya Dryomov's avatar Ilya Dryomov
Browse files

ceph: reencode gid_list when reconnecting 

On reconnect, cap and dentry releases are dropped and the fields
that follow must be reencoded into the freed space.  Currently these
are timestamp and gid_list, but gid_list isn't reencoded.  This
results in

  failed to decode message of type 24 v4: End of buffer

errors on the MDS.

While at it, make a change to encode gid_list unconditionally,
without regard to what head/which version was used as a result
of checking whether CEPH_FEATURE_FS_BTIME is supported or not.

URL: https://tracker.ceph.com/issues/48618


Fixes: 4f1ddb1e ("ceph: implement updated ceph_mds_request_head structure")
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
parent 5c8fe583

fs/ceph/mds_client.c

+22 −31
Original line number Diff line number Diff line
@@ -2475,6 +2475,22 @@ 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)

{

	struct ceph_timespec ts;

	int i;



	ceph_encode_timespec64(&ts, &req->r_stamp);

	ceph_encode_copy(p, &ts, sizeof(ts));



	/* gid_list */

	ceph_encode_32(p, req->r_cred->group_info->ngroups);

	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]));

}



/*

 * called under mdsc->mutex

 */
@@ -2491,7 +2507,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, 
	u64 ino1 = 0, ino2 = 0;

	int pathlen1 = 0, pathlen2 = 0;

	bool freepath1 = false, freepath2 = false;

	int len, i;

	int len;

	u16 releases;

	void *p, *end;

	int ret;
@@ -2517,17 +2533,10 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, 
		goto out_free1;

	}



	if (legacy) {

		/* Old style */

		len = sizeof(*head);

	} else {

		/* New style: add gid_list and any later fields */

		len = sizeof(struct ceph_mds_request_head) + sizeof(u32) +

		      (sizeof(u64) * req->r_cred->group_info->ngroups);

	}



	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 */

	len += sizeof(struct ceph_mds_request_release) *
@@ -2548,7 +2557,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, 
	msg->hdr.tid = cpu_to_le64(req->r_tid);



	/*

	 * The old ceph_mds_request_header didn't contain a version field, and

	 * The old ceph_mds_request_head didn't contain a version field, and

	 * one was added when we moved the message version from 3->4.

	 */

	if (legacy) {
@@ -2609,20 +2618,7 @@ static struct ceph_msg *create_request_message(struct ceph_mds_session *session, 


	head->num_releases = cpu_to_le16(releases);



	/* time stamp */

	{

		struct ceph_timespec ts;

		ceph_encode_timespec64(&ts, &req->r_stamp);

		ceph_encode_copy(&p, &ts, sizeof(ts));

	}



	/* gid list */

	if (!legacy) {

		ceph_encode_32(&p, req->r_cred->group_info->ngroups);

		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]));

	}

	encode_timestamp_and_gids(&p, req);



	if (WARN_ON_ONCE(p > end)) {

		ceph_msg_put(msg);
@@ -2730,13 +2726,8 @@ static int __prepare_send_request(struct ceph_mds_session *session, 
		/* remove cap/dentry releases from message */

		rhead->num_releases = 0;



		/* time stamp */

		p = msg->front.iov_base + req->r_request_release_offset;

		{

			struct ceph_timespec ts;

			ceph_encode_timespec64(&ts, &req->r_stamp);

			ceph_encode_copy(&p, &ts, sizeof(ts));

		}

		encode_timestamp_and_gids(&p, req);



		msg->front.iov_len = p - msg->front.iov_base;

		msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);