On Wed, 2020-12-16 at 22:38 +0100, Ilya Dryomov wrote: > 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: 4f1ddb1ea874 ("ceph: implement updated ceph_mds_request_head structure") > Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx> > --- > fs/ceph/mds_client.c | 53 ++++++++++++++++++-------------------------- > 1 file changed, 22 insertions(+), 31 deletions(-) > > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index 98c15ff2e599..840587037b59 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -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); Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
