[RFC PATCH 6/9] ceph: decode interval_sets for delegated inos

From: Jeff Layton <jlayton@kernel.org>
To: ceph-devel@vger.kernel.org
Cc: zyan@redhat.com, sage@redhat.com, idryomov@gmail.com,
	pdonnell@redhat.com
Subject: [RFC PATCH 6/9] ceph: decode interval_sets for delegated inos
Date: Fri, 10 Jan 2020 15:56:44 -0500	[thread overview]
Message-ID: <20200110205647.311023-7-jlayton@kernel.org> (raw)
In-Reply-To: <20200110205647.311023-1-jlayton@kernel.org>

Starting in Octopus, the MDS will hand out caps that allow the client
to do asynchronous file creates under certain conditions. As part of
that, the MDS will delegate ranges of inode numbers to the client.

Add the infrastructure to decode these ranges, and stuff them into an
xarray for later consumption by the async creation code.

Because the xarray code currently only handles unsigned long indexes,
and those are 32-bits on 32-bit arches, we only enable the decoding when
running on a 64-bit arch.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/ceph/mds_client.c | 107 +++++++++++++++++++++++++++++++++++++++----
 fs/ceph/mds_client.h |   5 +-
 2 files changed, 102 insertions(+), 10 deletions(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 8263f75badfc..852c46550d96 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -415,21 +415,108 @@ static int parse_reply_info_filelock(void **p, void *end,
 	return -EIO;
 }
 
+
+#if BITS_PER_LONG == 64
+
+#define DELEGATED_INO_AVAILABLE		xa_mk_value(1)
+
+static int parse_delegated_inos(void **p, void *end, struct ceph_mds_session *s)
+{
+	u32 sets;
+
+	ceph_decode_32_safe(p, end, sets, bad);
+	dout("got %u sets of delegated inodes\n", sets);
+	while (sets--) {
+		u64 start, len, ino;
+
+		ceph_decode_64_safe(p, end, start, bad);
+		ceph_decode_64_safe(p, end, len, bad);
+		while (len--) {
+			int err = xa_insert(&s->s_delegated_inos, ino = start++,
+					    DELEGATED_INO_AVAILABLE,
+					    GFP_KERNEL);
+			if (!err) {
+				dout("added delegated inode 0x%llx\n",
+				     start - 1);
+			} else if (err == -EBUSY) {
+				pr_warn("ceph: MDS delegated inode 0x%llx more than once.\n",
+					start - 1);
+			} else {
+				return err;
+			}
+		}
+	}
+	return 0;
+bad:
+	return -EIO;
+}
+
+static unsigned long get_delegated_ino(struct ceph_mds_session *s)
+{
+	unsigned long ino;
+	void *val;
+
+	xa_for_each(&s->s_delegated_inos, ino, val) {
+		val = xa_erase(&s->s_delegated_inos, ino);
+		if (val == DELEGATED_INO_AVAILABLE)
+			return ino;
+	}
+	return 0;
+}
+#else /* BITS_PER_LONG == 64 */
+/*
+ * FIXME: xarrays can't handle 64-bit indexes on a 32-bit arch. For now, just
+ * ignore delegated_inos on 32 bit arch. Maybe eventually add xarrays for top
+ * and bottom words?
+ */
+static int parse_delegated_inos(void **p, void *end, struct ceph_mds_session *s)
+{
+	u32 sets;
+
+	ceph_decode_32_safe(p, end, sets, bad);
+	if (sets)
+		ceph_decode_skip_n(p, end, sets * 2 * sizeof(__le64), bad);
+	return 0;
+bad:
+	return -EIO;
+}
+
+static inline unsigned long get_delegated_ino(struct ceph_mds_session *s)
+{
+	return 0;
+}
+#endif /* BITS_PER_LONG == 64 */
+
 /*
  * parse create results
  */
 static int parse_reply_info_create(void **p, void *end,
 				  struct ceph_mds_reply_info_parsed *info,
-				  u64 features)
+				  u64 features, struct ceph_mds_session *s)
 {
+	int ret;
+
 	if (features == (u64)-1 ||
 	    (features & CEPH_FEATURE_REPLY_CREATE_INODE)) {
-		/* Malformed reply? */
 		if (*p == end) {
+			/* Malformed reply? */
 			info->has_create_ino = false;
-		} else {
+		} else if (test_bit(CEPHFS_FEATURE_OCTOPUS, &s->s_features)) {
+			u8 struct_v, struct_compat;
+			u32 len;
+
 			info->has_create_ino = true;
+			ceph_decode_8_safe(p, end, struct_v, bad);
+			ceph_decode_8_safe(p, end, struct_compat, bad);
+			ceph_decode_32_safe(p, end, len, bad);
+			ceph_decode_64_safe(p, end, info->ino, bad);
+			ret = parse_delegated_inos(p, end, s);
+			if (ret)
+				return ret;
+		} else {
+			/* legacy */
 			ceph_decode_64_safe(p, end, info->ino, bad);
+			info->has_create_ino = true;
 		}
 	} else {
 		if (*p != end)
@@ -448,7 +535,7 @@ static int parse_reply_info_create(void **p, void *end,
  */
 static int parse_reply_info_extra(void **p, void *end,
 				  struct ceph_mds_reply_info_parsed *info,
-				  u64 features)
+				  u64 features, struct ceph_mds_session *s)
 {
 	u32 op = le32_to_cpu(info->head->op);
 
@@ -457,7 +544,7 @@ static int parse_reply_info_extra(void **p, void *end,
 	else if (op == CEPH_MDS_OP_READDIR || op == CEPH_MDS_OP_LSSNAP)
 		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);
+		return parse_reply_info_create(p, end, info, features, s);
 	else
 		return -EIO;
 }
@@ -465,7 +552,7 @@ static int parse_reply_info_extra(void **p, void *end,
 /*
  * parse entire mds reply
  */
-static int parse_reply_info(struct ceph_msg *msg,
+static int parse_reply_info(struct ceph_mds_session *s, struct ceph_msg *msg,
 			    struct ceph_mds_reply_info_parsed *info,
 			    u64 features)
 {
@@ -490,7 +577,7 @@ static int parse_reply_info(struct ceph_msg *msg,
 	ceph_decode_32_safe(&p, end, len, bad);
 	if (len > 0) {
 		ceph_decode_need(&p, end, len, bad);
-		err = parse_reply_info_extra(&p, p+len, info, features);
+		err = parse_reply_info_extra(&p, p+len, info, features, s);
 		if (err < 0)
 			goto out_bad;
 	}
@@ -558,6 +645,7 @@ void ceph_put_mds_session(struct ceph_mds_session *s)
 	if (refcount_dec_and_test(&s->s_ref)) {
 		if (s->s_auth.authorizer)
 			ceph_auth_destroy_authorizer(s->s_auth.authorizer);
+		xa_destroy(&s->s_delegated_inos);
 		kfree(s);
 	}
 }
@@ -645,6 +733,7 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
 	refcount_set(&s->s_ref, 1);
 	INIT_LIST_HEAD(&s->s_waiting);
 	INIT_LIST_HEAD(&s->s_unsafe);
+	xa_init(&s->s_delegated_inos);
 	s->s_num_cap_releases = 0;
 	s->s_cap_reconnect = 0;
 	s->s_cap_iterator = NULL;
@@ -2947,9 +3036,9 @@ 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;
 	if (test_bit(CEPHFS_FEATURE_REPLY_ENCODING, &session->s_features))
-		err = parse_reply_info(msg, rinfo, (u64)-1);
+		err = parse_reply_info(session, msg, rinfo, (u64)-1);
 	else
-		err = parse_reply_info(msg, rinfo, session->s_con.peer_features);
+		err = parse_reply_info(session, 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 27a7446e10d3..3db7ef47e1c9 100644
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -23,8 +23,10 @@ enum ceph_feature_type {
 	CEPHFS_FEATURE_RECLAIM_CLIENT,
 	CEPHFS_FEATURE_LAZY_CAP_WANTED,
 	CEPHFS_FEATURE_MULTI_RECONNECT,
+	CEPHFS_FEATURE_NAUTILUS = CEPHFS_FEATURE_MULTI_RECONNECT,
+	CEPHFS_FEATURE_OCTOPUS,
 
-	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_MULTI_RECONNECT,
+	CEPHFS_FEATURE_MAX = CEPHFS_FEATURE_OCTOPUS,
 };
 
 /*
@@ -201,6 +203,7 @@ struct ceph_mds_session {
 
 	struct list_head  s_waiting;  /* waiting requests */
 	struct list_head  s_unsafe;   /* unsafe requests */
+	struct xarray	  s_delegated_inos;
 };
 
 /*
-- 
2.24.1
