update flags patch

2 files changed, 27 insertions, 58 deletions

diff --git a/kmsg-export-flags.patch b/kmsg-export-flags.patch
index f520a55..4989050 100644
--- a/kmsg-export-flags.patch
+++ b/kmsg-export-flags.patch
@@ -1,31 +1,10 @@
 ---
- kernel/printk.c |   42 +++++++++++++++++++++++++++---------------
- 1 file changed, 27 insertions(+), 15 deletions(-)
+ kernel/printk.c |   23 +++++++++++++++++++++--
+ 1 file changed, 21 insertions(+), 2 deletions(-)
 
 --- a/kernel/printk.c
 +++ b/kernel/printk.c
-@@ -356,10 +356,28 @@ static void log_store(int facility, int
- 	log_next_seq++;
- }
- 
-+static bool msg_wants_prefix(const struct log *msg, enum log_flags prev)
-+{
-+	if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
-+		return false;
-+	if ((msg->flags & LOG_CONT) && (prev & LOG_CONT) &&
-+	    !(prev & LOG_NEWLINE))
-+		return false;
-+	return true;
-+}
-+
-+static bool msg_wants_newline(const struct log *msg, enum log_flags prev)
-+{
-+	if ((msg->flags & LOG_CONT) && !(msg->flags & LOG_NEWLINE))
-+		return false;
-+	return true;
-+}
-+
- /* /dev/kmsg - userspace message inject/listen interface */
+@@ -360,6 +360,7 @@ static void log_store(int facility, int
  struct devkmsg_user {
  	u64 seq;
  	u32 idx;
@@ -33,50 +12,39 @@
  	struct mutex lock;
  	char buf[8192];
  };
-@@ -424,6 +442,7 @@ static ssize_t devkmsg_read(struct file
- 	struct devkmsg_user *user = file->private_data;
+@@ -425,6 +426,7 @@ static ssize_t devkmsg_read(struct file
  	struct log *msg;
  	u64 ts_usec;
-+	char flag = '-';
  	size_t i;
++	char cont = '-';
  	size_t len;
  	ssize_t ret;
-@@ -462,8 +481,12 @@ static ssize_t devkmsg_read(struct file
+ 
+@@ -462,8 +464,25 @@ static ssize_t devkmsg_read(struct file
  	msg = log_from_idx(user->idx);
  	ts_usec = msg->ts_nsec;
  	do_div(ts_usec, 1000);
 -	len = sprintf(user->buf, "%u,%llu,%llu;",
 -		      (msg->facility << 3) | msg->level, user->seq, ts_usec);
-+	if (!msg_wants_prefix(msg, user->prev) ||
-+	    !msg_wants_newline(msg, user->prev))
-+		flag = '+';
-+	len = sprintf(user->buf,
-+		      "%u,%llu,%llu,%c;", (msg->facility << 3) | msg->level,
-+		      user->seq, ts_usec, flag);
++
++	/*
++	 * If we couldn't merge continuation line fragments during the print,
++	 * export the stored flags to allow an optional external merge of the
++	 * records. Merging the records isn't always neccessarily correct, like
++	 * when we hit a race during printing. In most cases though, it produces
++	 * better readable output. 'c' in the record flags mark the first
++	 * fragment of a line, '+' the following.
++	 */
++	if (msg->flags & LOG_CONT && !(user->prev & LOG_CONT))
++		cont = 'c';
++	else if ((msg->flags & LOG_CONT) ||
++		 (user->prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
++		cont = '+';
++
++	len = sprintf(user->buf, "%u,%llu,%llu,%c;",
++		      (msg->facility << 3) | msg->level,
++		      user->seq, ts_usec, cont);
++	user->prev = msg->flags;
  
  	/* escape non-printable characters */
  	for (i = 0; i < msg->text_len; i++) {
-@@ -847,21 +870,10 @@ static size_t msg_print_text(const struc
- {
- 	const char *text = log_text(msg);
- 	size_t text_size = msg->text_len;
--	bool prefix = true;
--	bool newline = true;
-+	bool prefix = msg_wants_prefix(msg, prev);
-+	bool newline = msg_wants_newline(msg, prev);
- 	size_t len = 0;
- 
--	if ((prev & LOG_CONT) && !(msg->flags & LOG_PREFIX))
--		prefix = false;
--
--	if (msg->flags & LOG_CONT) {
--		if ((prev & LOG_CONT) && !(prev & LOG_NEWLINE))
--			prefix = false;
--
--		if (!(msg->flags & LOG_NEWLINE))
--			newline = false;
--	}
--
- 	do {
- 		const char *next = memchr(text, '\n', text_size);
- 		size_t text_len;
diff --git a/series b/series
index f521fa0..d6822ef 100644
--- a/series
+++ b/series
@@ -1,3 +1,4 @@
 #test-modules.patch
 #test-console-blocked.patch
 kmsg-config-no-printk.patch
+kmsg-export-flags.patch