When the control daemon sees a node go down, it sends a DOWN message
through the ocfs2_control device.
Signed-off-by: Joel Becker <joel.becker@xxxxxxxxxx>
---
fs/ocfs2/stack_user.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 89 insertions(+), 5 deletions(-)
diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index ff8d307..a5e58e2 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -35,9 +35,21 @@
* of output is a supported protocol tag. All protocol tags are a single
* character followed by a two hex digit version number. Currently the
* only things supported is T01, for "Text-base version 0x01". Next, the
- * client writes the version they would like to use. If the version tag
- * written is unknown, -EINVAL is returned. Once the negotiation is
- * complete, the client can start sending messages.
+ * client writes the version they would like to use, including the newline.
+ * Thus, the protocol tag is 'T01\n'. If the version tag written is
+ * unknown, -EINVAL is returned. Once the negotiation is complete, the
+ * client can start sending messages.
+ *
+ * The T01 protocol only has one message, "DOWN". It has the following
+ * syntax:
+ *
+ * DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline>
+ *
+ * eg:
+ *
+ * DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n
+ *
+ * This is 47 characters.
*/
/*
@@ -49,6 +61,11 @@
#define OCFS2_CONTROL_HANDSHAKE_INVALID (0)
#define OCFS2_CONTROL_HANDSHAKE_READ (1)
#define OCFS2_CONTROL_HANDSHAKE_VALID (2)
+#define OCFS2_CONTROL_MESSAGE_DOWN "DOWN"
+#define OCFS2_CONTROL_MESSAGE_DOWN_LEN 4
+#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47
+#define OCFS2_TEXT_UUID_LEN 32
+#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8
/*
* ocfs2_live_connection is refcounted because the filesystem and
@@ -149,7 +166,7 @@ static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c)
kfree(c);
}
-static ssize_t ocfs2_control_cfu(char *target, size_t target_len,
+static ssize_t ocfs2_control_cfu(void *target, size_t target_len,
const char __user *buf, size_t count)
{
/* The T01 expects write(2) calls to have exactly one command */
@@ -185,6 +202,73 @@ static ssize_t ocfs2_control_validate_handshake(struct file *file,
return count;
}
+static void ocfs2_control_send_down(const char *uuid,
+ int nodenum)
+{
+ struct ocfs2_live_connection *c;
+
+ mutex_lock(&ocfs2_control_lock);
+
+ c = ocfs2_connection_find(uuid);
+ if (c) {
+ BUG_ON(c->oc_conn == NULL);
+ c->oc_conn->cc_recovery_handler(nodenum,
+ c->oc_conn->cc_recovery_data);
+ }
+
+ mutex_unlock(&ocfs2_control_lock);
+}
+
+/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */
+struct ocfs2_control_message_down {
+ char tag[OCFS2_CONTROL_MESSAGE_DOWN_LEN];
+ char space1;
+ char uuid[OCFS2_TEXT_UUID_LEN];
+ char space2;
+ char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
+ char newline;
+};
+
+static ssize_t ocfs2_control_message(struct file *file,
+ const char __user *buf,
+ size_t count)
+{
+ ssize_t ret;
+ char *p = NULL;
+ long nodenum;
+ struct ocfs2_control_message_down msg;
+
+ /* Try to catch padding issues */
+ WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=
+ (sizeof(msg.tag) + sizeof(msg.space1)));
+
+ memset(&msg, 0, sizeof(struct ocfs2_control_message_down));
+ ret = ocfs2_control_cfu(&msg, OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN,
+ buf, count);
+ if (ret != count)
+ return ret;
+
+ if (strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN,
+ strlen(OCFS2_CONTROL_MESSAGE_DOWN)))
+ return -EINVAL;
+
+ if ((msg.space1 != ' ') || (msg.space2 != ' ') ||
+ (msg.newline != '\n'))
+ return -EINVAL;
+ msg.space1 = msg.space2 = msg.newline = '\0';
+
+ nodenum = simple_strtol(msg.nodestr, &p, 16);
+ if (!p || *p)
+ return -EINVAL;
+
+ if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
+ (nodenum > INT_MAX) || (nodenum < 0))
+ return -ERANGE;
+
+ ocfs2_control_send_down(msg.uuid, nodenum);
+
+ return count;
+}
static ssize_t ocfs2_control_write(struct file *file,
const char __user *buf,
@@ -204,7 +288,7 @@ static ssize_t ocfs2_control_write(struct file *file,
break;
case OCFS2_CONTROL_HANDSHAKE_VALID:
- ret = count; /* XXX */
+ ret = ocfs2_control_message(file, buf, count);
break;
default:
--
1.5.3.8
--
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