ceph: support versioned reply

In versioned reply, inodestat, dirstat and lease are encoded with
version, compat_version and struct_len.

Based on a patch from Jos Collin <jcollin@redhat.com>.

Link: http://tracker.ceph.com/issues/26936
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

2 files changed, 166 insertions, 49 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index f2f57775d2d5..e87544e42488 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -65,6 +65,29 @@ static const struct ceph_connection_operations mds_con_ops;
  * mds reply parsing
  */
 
+static int parse_reply_info_quota(void **p, void *end,
+				  struct ceph_mds_reply_info_in *info)
+{
+	u8 struct_v, struct_compat;
+	u32 struct_len;
+
+	ceph_decode_8_safe(p, end, struct_v, bad);
+	ceph_decode_8_safe(p, end, struct_compat, bad);
+	/* struct_v is expected to be >= 1. we only
+	 * understand encoding with struct_compat == 1. */
+	if (!struct_v || struct_compat != 1)
+		goto bad;
+	ceph_decode_32_safe(p, end, struct_len, bad);
+	ceph_decode_need(p, end, struct_len, bad);
+	end = *p + struct_len;
+	ceph_decode_64_safe(p, end, info->max_bytes, bad);
+	ceph_decode_64_safe(p, end, info->max_files, bad);
+	*p = end;
+	return 0;
+bad:
+	return -EIO;
+}
+
 /*
  * parse individual inode info
  */
@@ -72,8 +95,24 @@ static int parse_reply_info_in(void **p, void *end,
 			       struct ceph_mds_reply_info_in *info,
 			       u64 features)
 {
-	int err = -EIO;
+	int err = 0;
+	u8 struct_v = 0;
 
+	if (features == (u64)-1) {
+		u32 struct_len;
+		u8 struct_compat;
+		ceph_decode_8_safe(p, end, struct_v, bad);
+		ceph_decode_8_safe(p, end, struct_compat, bad);
+		/* struct_v is expected to be >= 1. we only understand
+		 * encoding with struct_compat == 1. */
+		if (!struct_v || struct_compat != 1)
+			goto bad;
+		ceph_decode_32_safe(p, end, struct_len, bad);
+		ceph_decode_need(p, end, struct_len, bad);
+		end = *p + struct_len;
+	}
+
+	ceph_decode_need(p, end, sizeof(struct ceph_mds_reply_inode), bad);
 	info->in = *p;
 	*p += sizeof(struct ceph_mds_reply_inode) +
 		sizeof(*info->in->fragtree.splits) *
@@ -91,49 +130,127 @@ static int parse_reply_info_in(void **p, void *end,
 	info->xattr_data = *p;
 	*p += info->xattr_len;
 
-	if (features & CEPH_FEATURE_MDS_INLINE_DATA) {
+	if (features == (u64)-1) {
+		/* inline data */
 		ceph_decode_64_safe(p, end, info->inline_version, bad);
 		ceph_decode_32_safe(p, end, info->inline_len, bad);
 		ceph_decode_need(p, end, info->inline_len, bad);
 		info->inline_data = *p;
 		*p += info->inline_len;
-	} else
-		info->inline_version = CEPH_INLINE_NONE;
+		/* quota */
+		err = parse_reply_info_quota(p, end, info);
+		if (err < 0)
+			goto out_bad;
+		/* pool namespace */
+		ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
+		if (info->pool_ns_len > 0) {
+			ceph_decode_need(p, end, info->pool_ns_len, bad);
+			info->pool_ns_data = *p;
+			*p += info->pool_ns_len;
+		}
+		/* btime, change_attr */
+		{
+			struct ceph_timespec btime;
+			u64 change_attr;
+			ceph_decode_need(p, end, sizeof(btime), bad);
+			ceph_decode_copy(p, &btime, sizeof(btime));
+			ceph_decode_64_safe(p, end, change_attr, bad);
+		}
 
-	if (features & CEPH_FEATURE_MDS_QUOTA) {
+		*p = end;
+	} else {
+		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);
+			ceph_decode_need(p, end, info->inline_len, bad);
+			info->inline_data = *p;
+			*p += info->inline_len;
+		} else
+			info->inline_version = CEPH_INLINE_NONE;
+
+		if (features & CEPH_FEATURE_MDS_QUOTA) {
+			err = parse_reply_info_quota(p, end, info);
+			if (err < 0)
+				goto out_bad;
+		} else {
+			info->max_bytes = 0;
+			info->max_files = 0;
+		}
+
+		info->pool_ns_len = 0;
+		info->pool_ns_data = NULL;
+		if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
+			ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
+			if (info->pool_ns_len > 0) {
+				ceph_decode_need(p, end, info->pool_ns_len, bad);
+				info->pool_ns_data = *p;
+				*p += info->pool_ns_len;
+			}
+		}
+	}
+	return 0;
+bad:
+	err = -EIO;
+out_bad:
+	return err;
+}
+
+static int parse_reply_info_dir(void **p, void *end,
+				struct ceph_mds_reply_dirfrag **dirfrag,
+				u64 features)
+{
+	if (features == (u64)-1) {
 		u8 struct_v, struct_compat;
 		u32 struct_len;
-
-		/*
-		 * both struct_v and struct_compat are expected to be >= 1
-		 */
 		ceph_decode_8_safe(p, end, struct_v, bad);
 		ceph_decode_8_safe(p, end, struct_compat, bad);
-		if (!struct_v || !struct_compat)
+		/* struct_v is expected to be >= 1. we only understand
+		 * encoding whose struct_compat == 1. */
+		if (!struct_v || struct_compat != 1)
 			goto bad;
 		ceph_decode_32_safe(p, end, struct_len, bad);
 		ceph_decode_need(p, end, struct_len, bad);
-		ceph_decode_64_safe(p, end, info->max_bytes, bad);
-		ceph_decode_64_safe(p, end, info->max_files, bad);
-	} else {
-		info->max_bytes = 0;
-		info->max_files = 0;
+		end = *p + struct_len;
 	}
 
-	info->pool_ns_len = 0;
-	info->pool_ns_data = NULL;
-	if (features & CEPH_FEATURE_FS_FILE_LAYOUT_V2) {
-		ceph_decode_32_safe(p, end, info->pool_ns_len, bad);
-		if (info->pool_ns_len > 0) {
-			ceph_decode_need(p, end, info->pool_ns_len, bad);
-			info->pool_ns_data = *p;
-			*p += info->pool_ns_len;
-		}
+	ceph_decode_need(p, end, sizeof(**dirfrag), bad);
+	*dirfrag = *p;
+	*p += sizeof(**dirfrag) + sizeof(u32) * le32_to_cpu((*dirfrag)->ndist);
+	if (unlikely(*p > end))
+		goto bad;
+	if (features == (u64)-1)
+		*p = end;
+	return 0;
+bad:
+	return -EIO;
+}
+
+static int parse_reply_info_lease(void **p, void *end,
+				  struct ceph_mds_reply_lease **lease,
+				  u64 features)
+{
+	if (features == (u64)-1) {
+		u8 struct_v, struct_compat;
+		u32 struct_len;
+		ceph_decode_8_safe(p, end, struct_v, bad);
+		ceph_decode_8_safe(p, end, struct_compat, bad);
+		/* struct_v is expected to be >= 1. we only understand
+		 * encoding whose struct_compat == 1. */
+		if (!struct_v || struct_compat != 1)
+			goto bad;
+		ceph_decode_32_safe(p, end, struct_len, bad);
+		ceph_decode_need(p, end, struct_len, bad);
+		end = *p + struct_len;
 	}
 
+	ceph_decode_need(p, end, sizeof(**lease), bad);
+	*lease = *p;
+	*p += sizeof(**lease);
+	if (features == (u64)-1)
+		*p = end;
 	return 0;
 bad:
-	return err;
+	return -EIO;
 }
 
 /*
@@ -151,20 +268,18 @@ static int parse_reply_info_trace(void **p, void *end,
 		if (err < 0)
 			goto out_bad;
 
-		if (unlikely(*p + sizeof(*info->dirfrag) > end))
-			goto bad;
-		info->dirfrag = *p;
-		*p += sizeof(*info->dirfrag) +
-			sizeof(u32)*le32_to_cpu(info->dirfrag->ndist);
-		if (unlikely(*p > end))
-			goto bad;
+		err = parse_reply_info_dir(p, end, &info->dirfrag, features);
+		if (err < 0)
+			goto out_bad;
 
 		ceph_decode_32_safe(p, end, info->dname_len, bad);
 		ceph_decode_need(p, end, info->dname_len, bad);
 		info->dname = *p;
 		*p += info->dname_len;
-		info->dlease = *p;
-		*p += sizeof(*info->dlease);
+
+		err = parse_reply_info_lease(p, end, &info->dlease, features);
+		if (err < 0)
+			goto out_bad;
 	}
 
 	if (info->head->is_target) {
@@ -187,20 +302,16 @@ out_bad:
 /*
  * parse readdir results
  */
-static int parse_reply_info_dir(void **p, void *end,
+static int parse_reply_info_readdir(void **p, void *end,
 				struct ceph_mds_reply_info_parsed *info,
 				u64 features)
 {
 	u32 num, i = 0;
 	int err;
 
-	info->dir_dir = *p;
-	if (*p + sizeof(*info->dir_dir) > end)
-		goto bad;
-	*p += sizeof(*info->dir_dir) +
-		sizeof(u32)*le32_to_cpu(info->dir_dir->ndist);
-	if (*p > end)
-		goto bad;
+	err = parse_reply_info_dir(p, end, &info->dir_dir, features);
+	if (err < 0)
+		goto out_bad;
 
 	ceph_decode_need(p, end, sizeof(num) + 2, bad);
 	num = ceph_decode_32(p);
@@ -226,15 +337,16 @@ static int parse_reply_info_dir(void **p, void *end,
 	while (num) {
 		struct ceph_mds_reply_dir_entry *rde = info->dir_entries + i;
 		/* dentry */
-		ceph_decode_need(p, end, sizeof(u32)*2, bad);
-		rde->name_len = ceph_decode_32(p);
+		ceph_decode_32_safe(p, end, rde->name_len, bad);
 		ceph_decode_need(p, end, rde->name_len, bad);
 		rde->name = *p;
 		*p += rde->name_len;
 		dout("parsed dir dname '%.*s'\n", rde->name_len, rde->name);
-		rde->lease = *p;
-		*p += sizeof(struct ceph_mds_reply_lease);
 
+		/* dentry lease */
+		err = parse_reply_info_lease(p, end, &rde->lease, features);
+		if (err)
+			goto out_bad;
 		/* inode */
 		err = parse_reply_info_in(p, end, &rde->inode, features);
 		if (err < 0)
@@ -285,7 +397,8 @@ static int parse_reply_info_create(void **p, void *end,
 				  struct ceph_mds_reply_info_parsed *info,
 				  u64 features)
 {
-	if (features & CEPH_FEATURE_REPLY_CREATE_INODE) {
+	if (features == (u64)-1 ||
+	    (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
 		if (*p == end) {
 			info->has_create_ino = false;
 		} else {
@@ -314,7 +427,7 @@ static int parse_reply_info_extra(void **p, void *end,
 	if (op == CEPH_MDS_OP_GETFILELOCK)
 		return parse_reply_info_filelock(p, end, info, features);
 	else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
-		return parse_reply_info_dir(p, end, info, features);
+		return parse_reply_info_readdir(p, end, info, features);
 	else if (op == CEPH_MDS_OP_CREATE)
 		return parse_reply_info_create(p, end, info, features);
 	else
@@ -2657,7 +2770,10 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
 
 	dout("handle_reply tid %lld result %d\n", tid, result);
 	rinfo = &req->r_reply_info;
-	err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
+	if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
+		err = parse_reply_info(msg, rinfo, (u64)-1);
+	else
+		err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
 	mutex_unlock(&mdsc->mutex);
 
 	mutex_lock(&session->s_mutex);
diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index d3a5c4046316..0919aacc1af3 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -26,6 +26,7 @@
 #define CEPHFS_FEATURES_CLIENT_SUPPORTED { 	\
 	0, 1, 2, 3, 4, 5, 6, 7,			\
 	CEPHFS_FEATURE_MIMIC,			\
+	CEPHFS_FEATURE_REPLY_ENCODING,		\
 	CEPHFS_FEATURE_LAZY_CAP_WANTED,		\
 	CEPHFS_FEATURE_MULTI_RECONNECT,		\
 }