netconsole: append msgid to sysdata

Add msgcounter to the netconsole_target struct to generate message IDs.
If the msgid_enabled attribute is true, increment msgcounter and append
msgid=<msgcounter> to sysdata buffer before sending the message.

Signed-off-by: Gustavo Luiz Duarte <gustavold@gmail.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 5e66a568954f17642a8959d8bac75b7e814ea260..e3722de08ea9f08b95df2249686e231ad44a8b35 100644 (file)
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -125,6 +125,7 @@ enum sysdata_feature {
  * @extradata_complete:        Cached, formatted string of append
  * @userdata_length:   String length of usedata in extradata_complete.
  * @sysdata_fields:    Sysdata features enabled.
+ * @msgcounter:        Message sent counter.
  * @stats:     Packet send stats for the target. Used for debugging.
  * @enabled:   On / off knob to enable / disable target.
  *             Visible from userspace (read-write).
@@ -155,6 +156,8 @@ struct netconsole_target {
        size_t                  userdata_length;
        /* bit-wise with sysdata_feature bits */
        u32                     sysdata_fields;
+       /* protected by target_list_lock */
+       u32                     msgcounter;
 #endif
        struct netconsole_target_stats stats;
        bool                    enabled;
@@ -1362,6 +1365,14 @@ static int sysdata_append_release(struct netconsole_target *nt, int offset)
                         init_utsname()->release);
 }
 
+static int sysdata_append_msgid(struct netconsole_target *nt, int offset)
+{
+       wrapping_assign_add(nt->msgcounter, 1);
+       return scnprintf(&nt->extradata_complete[offset],
+                        MAX_EXTRADATA_ENTRY_LEN, " msgid=%u\n",
+                        nt->msgcounter);
+}
+
 /*
  * prepare_extradata - append sysdata at extradata_complete in runtime
  * @nt: target to send message to
@@ -1384,6 +1395,8 @@ static int prepare_extradata(struct netconsole_target *nt)
                extradata_len += sysdata_append_taskname(nt, extradata_len);
        if (nt->sysdata_fields & SYSDATA_RELEASE)
                extradata_len += sysdata_append_release(nt, extradata_len);
+       if (nt->sysdata_fields & SYSDATA_MSGID)
+               extradata_len += sysdata_append_msgid(nt, extradata_len);
 
        WARN_ON_ONCE(extradata_len >
                     MAX_EXTRADATA_ENTRY_LEN * MAX_EXTRADATA_ITEMS);