Revert "printk: make reading the kernel log flush pending lines"
This reverts commit bfd8d3f23b51018388be0411ccbc2d56277fe294.
It turns out that this flushes things much too aggressiverly, and causes
lines to break up when the system logger races with new continuation
lines being printed.
There's a pending patch to make printk() flushing much more
straightforward, but it's too invasive for 4.9, so in the meantime let's
just not make the system message logging flush continuation lines.
They'll be flushed by the final newline anyway.
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5028f4f..f7a55e9 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -783,8 +783,6 @@
return ret;
}
-static void cont_flush(void);
-
static ssize_t devkmsg_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
@@ -800,7 +798,6 @@
if (ret)
return ret;
raw_spin_lock_irq(&logbuf_lock);
- cont_flush();
while (user->seq == log_next_seq) {
if (file->f_flags & O_NONBLOCK) {
ret = -EAGAIN;
@@ -863,7 +860,6 @@
return -ESPIPE;
raw_spin_lock_irq(&logbuf_lock);
- cont_flush();
switch (whence) {
case SEEK_SET:
/* the first record */
@@ -902,7 +898,6 @@
poll_wait(file, &log_wait, wait);
raw_spin_lock_irq(&logbuf_lock);
- cont_flush();
if (user->seq < log_next_seq) {
/* return error when data has vanished underneath us */
if (user->seq < log_first_seq)
@@ -1289,7 +1284,6 @@
size_t skip;
raw_spin_lock_irq(&logbuf_lock);
- cont_flush();
if (syslog_seq < log_first_seq) {
/* messages are gone, move to first one */
syslog_seq = log_first_seq;
@@ -1349,7 +1343,6 @@
return -ENOMEM;
raw_spin_lock_irq(&logbuf_lock);
- cont_flush();
if (buf) {
u64 next_seq;
u64 seq;
@@ -1511,7 +1504,6 @@
/* Number of chars in the log buffer */
case SYSLOG_ACTION_SIZE_UNREAD:
raw_spin_lock_irq(&logbuf_lock);
- cont_flush();
if (syslog_seq < log_first_seq) {
/* messages are gone, move to first one */
syslog_seq = log_first_seq;
@@ -3028,7 +3020,6 @@
dumper->active = true;
raw_spin_lock_irqsave(&logbuf_lock, flags);
- cont_flush();
dumper->cur_seq = clear_seq;
dumper->cur_idx = clear_idx;
dumper->next_seq = log_next_seq;
@@ -3119,7 +3110,6 @@
bool ret;
raw_spin_lock_irqsave(&logbuf_lock, flags);
- cont_flush();
ret = kmsg_dump_get_line_nolock(dumper, syslog, line, size, len);
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
@@ -3162,7 +3152,6 @@
goto out;
raw_spin_lock_irqsave(&logbuf_lock, flags);
- cont_flush();
if (dumper->cur_seq < log_first_seq) {
/* messages are gone, move to first available one */
dumper->cur_seq = log_first_seq;