struct dlm_query_join_packet is made up of four one-byte fields. They
are effectively in big-endian order already. However, little-endian
machines swap them before putting the packet on the wire (because
query_join's response is a status, and that status is treated as a u32
on the wire). Thus, a big-endian and little-endian machines will
treat this structure differently.
The solution is to have little-endian machines swap the structure when
converting from the structure to the u32 representation.
Signed-off-by: Joel Becker <[EMAIL PROTECTED]>
---
fs/ocfs2/dlm/dlmcommon.h | 20 +++++----
fs/ocfs2/dlm/dlmdomain.c | 95 +++++++++++++++++++++++++++++++---------------
2 files changed, 75 insertions(+), 40 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index 9843ee1..1f93963 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -602,17 +602,19 @@ enum dlm_query_join_response_code {
JOIN_PROTOCOL_MISMATCH,
};
+struct dlm_query_join_packet {
+ u8 code; /* Response code. dlm_minor and fs_minor
+ are only valid if this is JOIN_OK */
+ u8 dlm_minor; /* The minor version of the protocol the
+ dlm is speaking. */
+ u8 fs_minor; /* The minor version of the protocol the
+ filesystem is speaking. */
+ u8 reserved;
+};
+
union dlm_query_join_response {
u32 intval;
- struct {
- u8 code; /* Response code. dlm_minor and fs_minor
- are only valid if this is JOIN_OK */
- u8 dlm_minor; /* The minor version of the protocol the
- dlm is speaking. */
- u8 fs_minor; /* The minor version of the protocol the
- filesystem is speaking. */
- u8 reserved;
- } packet;
+ struct dlm_query_join_packet packet;
};
struct dlm_lock_request
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index de802a7..e77f5d8 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -723,14 +723,46 @@ static int dlm_query_join_proto_check(char *proto_type,
int node,
return compatible;
}
+/*
+ * struct dlm_query_join_packet is made up of four one-byte fields. They
+ * are effectively in big-endian order already. However, little-endian
+ * machines swap them before putting the packet on the wire (because
+ * query_join's response is a status, and that status is treated as a u32
+ * on the wire). Thus, a big-endian and little-endian machines will treat
+ * this structure differently.
+ *
+ * The solution is to have little-endian machines swap the structure when
+ * converting from the structure to the u32 representation. This will
+ * result in the structure having the correct format on the wire no matter
+ * the host endian format.
+ */
+static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
+ u32 *wire)
+{
+ union dlm_query_join_response response;
+
+ response.packet = *packet;
+ *wire = cpu_to_be32(response.intval);
+}
+
+static void dlm_query_join_wire_to_packet(u32 wire,
+ struct dlm_query_join_packet *packet)
+{
+ union dlm_query_join_response response;
+
+ response.intval = cpu_to_be32(wire);
+ *packet = response.packet;
+}
+
static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
void **ret_data)
{
struct dlm_query_join_request *query;
- union dlm_query_join_response response = {
- .packet.code = JOIN_DISALLOW,
+ struct dlm_query_join_packet packet = {
+ .code = JOIN_DISALLOW,
};
struct dlm_ctxt *dlm = NULL;
+ u32 response;
u8 nodenum;
query = (struct dlm_query_join_request *) msg->buf;
@@ -747,11 +779,11 @@ static int dlm_query_join_handler(struct o2net_msg *msg,
u32 len, void *data,
mlog(0, "node %u is not in our live map yet\n",
query->node_idx);
- response.packet.code = JOIN_DISALLOW;
+ packet.code = JOIN_DISALLOW;
goto respond;
}
- response.packet.code = JOIN_OK_NO_MAP;
+ packet.code = JOIN_OK_NO_MAP;
spin_lock(&dlm_domain_lock);
dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
@@ -770,7 +802,7 @@ static int dlm_query_join_handler(struct o2net_msg *msg,
u32 len, void *data,
mlog(0, "disallow join as node %u does not "
"have node %u in its nodemap\n",
query->node_idx, nodenum);
- response.packet.code = JOIN_DISALLOW;
+ packet.code = JOIN_DISALLOW;
goto unlock_respond;
}
}
@@ -790,23 +822,23 @@ static int dlm_query_join_handler(struct o2net_msg *msg,
u32 len, void *data,
/*If this is a brand new context and we
* haven't started our join process yet, then
* the other node won the race. */
- response.packet.code = JOIN_OK_NO_MAP;
+ packet.code = JOIN_OK_NO_MAP;
} else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
/* Disallow parallel joins. */
- response.packet.code = JOIN_DISALLOW;
+ packet.code = JOIN_DISALLOW;
} else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
mlog(0, "node %u trying to join, but recovery "
"is ongoing.\n", bit);
- response.packet.code = JOIN_DISALLOW;
+ packet.code = JOIN_DISALLOW;
} else if (test_bit(bit, dlm->recovery_map)) {
mlog(0, "node %u trying to join, but it "
"still needs recovery.\n", bit);
- response.packet.code = JOIN_DISALLOW;
+ packet.code = JOIN_DISALLOW;
} else if (test_bit(bit, dlm->domain_map)) {
mlog(0, "node %u trying to join, but it "
"is still in the domain! needs recovery?\n",
bit);
- response.packet.code = JOIN_DISALLOW;
+ packet.code = JOIN_DISALLOW;
} else {
/* Alright we're fully a part of this domain
* so we keep some state as to who's joining
@@ -824,14 +856,14 @@ static int dlm_query_join_handler(struct o2net_msg *msg,
u32 len, void *data,
* We're compatible, return our
* minor number
*/
- response.packet.dlm_minor =
+ packet.dlm_minor =
dlm->dlm_locking_proto.pv_minor;
- response.packet.fs_minor =
+ packet.fs_minor =
dlm->fs_locking_proto.pv_minor;
- response.packet.code = JOIN_OK;
+ packet.code = JOIN_OK;
__dlm_set_joining_node(dlm, query->node_idx);
} else {
- response.packet.code =
+ packet.code =
JOIN_PROTOCOL_MISMATCH;
}
}
@@ -842,9 +874,10 @@ unlock_respond:
spin_unlock(&dlm_domain_lock);
respond:
- mlog(0, "We respond with %u\n", response.packet.code);
+ mlog(0, "We respond with %u\n", packet.code);
- return response.intval;
+ dlm_query_join_packet_to_wire(&packet, &response);
+ return response;
}
static int dlm_assert_joined_handler(struct o2net_msg *msg, u32 len, void
*data,
@@ -980,7 +1013,8 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
{
int status;
struct dlm_query_join_request join_msg;
- union dlm_query_join_response join_resp;
+ struct dlm_query_join_packet packet;
+ u32 join_resp;
mlog(0, "querying node %d\n", node);
@@ -996,11 +1030,12 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
sizeof(join_msg), node,
- &join_resp.intval);
+ &join_resp);
if (status < 0 && status != -ENOPROTOOPT) {
mlog_errno(status);
goto bail;
}
+ dlm_query_join_wire_to_packet(join_resp, &packet);
/* -ENOPROTOOPT from the net code means the other side isn't
listening for our message type -- that's fine, it means
@@ -1009,10 +1044,10 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
if (status == -ENOPROTOOPT) {
status = 0;
*response = JOIN_OK_NO_MAP;
- } else if (join_resp.packet.code == JOIN_DISALLOW ||
- join_resp.packet.code == JOIN_OK_NO_MAP) {
- *response = join_resp.packet.code;
- } else if (join_resp.packet.code == JOIN_PROTOCOL_MISMATCH) {
+ } else if (packet.code == JOIN_DISALLOW ||
+ packet.code == JOIN_OK_NO_MAP) {
+ *response = packet.code;
+ } else if (packet.code == JOIN_PROTOCOL_MISMATCH) {
mlog(ML_NOTICE,
"This node requested DLM locking protocol %u.%u and "
"filesystem locking protocol %u.%u. At least one of "
@@ -1024,14 +1059,12 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
dlm->fs_locking_proto.pv_minor,
node);
status = -EPROTO;
- *response = join_resp.packet.code;
- } else if (join_resp.packet.code == JOIN_OK) {
- *response = join_resp.packet.code;
+ *response = packet.code;
+ } else if (packet.code == JOIN_OK) {
+ *response = packet.code;
/* Use the same locking protocol as the remote node */
- dlm->dlm_locking_proto.pv_minor =
- join_resp.packet.dlm_minor;
- dlm->fs_locking_proto.pv_minor =
- join_resp.packet.fs_minor;
+ dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
+ dlm->fs_locking_proto.pv_minor = packet.fs_minor;
mlog(0,
"Node %d responds JOIN_OK with DLM locking protocol "
"%u.%u and fs locking protocol %u.%u\n",
@@ -1043,11 +1076,11 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
} else {
status = -EINVAL;
mlog(ML_ERROR, "invalid response %d from node %u\n",
- join_resp.packet.code, node);
+ packet.code, node);
}
mlog(0, "status %d, node %d response is %d\n", status, node,
- *response);
+ *response);
bail:
return status;
--
1.5.3.8
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