pstore: cleanups to pstore_dump()

pstore_dump() can be called with many different "reason" codes. Save
the name of the code in the persistent store record.

Also - only worthwhile calling pstore_mkfile for KMSG_DUMP_OOPS - that
is the only one where the kernel will continue running.
Reviewed-by: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

fs/pstore/platform.c

@@ -48,6 +48,10 @@ void pstore_set_kmsg_bytes(int bytes)
 /* Tag each group of saved records with a sequence number */
 static int	oopscount;
 
+static char *reason_str[] = {
+	"Oops", "Panic", "Kexec", "Restart", "Halt", "Poweroff", "Emergency"
+};
+
 /*
  * callback from kmsg_dump. (s2,l2) has the most recently
  * written bytes, older bytes are in (s1,l1). Save as much
@@ -61,15 +65,20 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 	unsigned long	s1_start, s2_start;
 	unsigned long	l1_cpy, l2_cpy;
 	unsigned long	size, total = 0;
-	char		*dst;
+	char		*dst, *why;
 	u64		id;
 	int		hsize, part = 1;
 
+	if (reason < ARRAY_SIZE(reason_str))
+		why = reason_str[reason];
+	else
+		why = "Unknown";
+
 	mutex_lock(&psinfo->buf_mutex);
 	oopscount++;
 	while (total < kmsg_bytes) {
 		dst = psinfo->buf;
-		hsize = sprintf(dst, "Oops#%d Part%d\n", oopscount, part++);
+		hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part++);
 		size = psinfo->bufsize - hsize;
 		dst += hsize;
 
@@ -86,7 +95,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
 		memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy);
 
 		id = psinfo->write(PSTORE_TYPE_DMESG, hsize + l1_cpy + l2_cpy);
-		if (pstore_is_mounted())
+		if (reason == KMSG_DUMP_OOPS && pstore_is_mounted())
 			pstore_mkfile(PSTORE_TYPE_DMESG, psinfo->name, id,
 				      psinfo->buf, hsize + l1_cpy + l2_cpy,
 				      CURRENT_TIME, psinfo->erase);