There will be needed some fixes in the check for free space. They will
be easier if the code is moved outside of the quite long log_store()
function.
This patch does not change the existing behavior.
Signed-off-by: Petr Mladek <pmla...@suse.cz>
---
kernel/printk/printk.c | 44 +++++++++++++++++++++++++++++---------------
1 file changed, 29 insertions(+), 15 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index a45b50962295..cc7d7defce24 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -297,6 +297,34 @@ static u32 log_next(u32 idx)
return idx + msg->len;
}
+/* check whether there is enough free space for the given message */
+static int logbuf_has_space(u32 msg_size)
+{
+ u32 free;
+
+ if (log_next_idx > log_first_idx)
+ free = max(log_buf_len - log_next_idx, log_first_idx);
+ else
+ free = log_first_idx - log_next_idx;
+
+ /*
+ * We need space also for an empty header that signalizes wrapping
+ * of the buffer.
+ */
+ return free >= msg_size + sizeof(struct printk_log);
+}
+
+static void log_make_free_space(u32 msg_size)
+{
+ while (log_first_seq < log_next_seq) {
+ if (logbuf_has_space(msg_size))
+ return;
+ /* drop old messages until we have enough continuous space */
+ log_first_idx = log_next(log_first_idx);
+ log_first_seq++;
+ }
+}
+
/* insert record into the buffer, discard old ones, update heads */
static void log_store(int facility, int level,
enum log_flags flags, u64 ts_nsec,
@@ -311,21 +339,7 @@ static void log_store(int facility, int level,
pad_len = (-size) & (LOG_ALIGN - 1);
size += pad_len;
- while (log_first_seq < log_next_seq) {
- u32 free;
-
- if (log_next_idx > log_first_idx)
- free = max(log_buf_len - log_next_idx, log_first_idx);
- else
- free = log_first_idx - log_next_idx;
-
- if (free >= size + sizeof(struct printk_log))
- break;
-
- /* drop old messages until we have enough contiuous space */
- log_first_idx = log_next(log_first_idx);
- log_first_seq++;
- }
+ log_make_free_space(size);
if (log_next_idx + size + sizeof(struct printk_log) > log_buf_len) {
/*
--
1.8.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
