printk: make reading the kernel log flush pending lines

[cascardo/linux.git] / kernel / printk / printk.c

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f6fe60d..170d3a8 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -783,6 +783,8 @@ static ssize_t devkmsg_write(struct kiocb *iocb, struct iov_iter *from)
        return ret;
 }
 
+static void cont_flush(void);
+
 static ssize_t devkmsg_read(struct file *file, char __user *buf,
                            size_t count, loff_t *ppos)
 {
@@ -798,6 +800,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
        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;
@@ -860,6 +863,7 @@ static loff_t devkmsg_llseek(struct file *file, loff_t offset, int whence)
                return -ESPIPE;
 
        raw_spin_lock_irq(&logbuf_lock);
+       cont_flush();
        switch (whence) {
        case SEEK_SET:
                /* the first record */
@@ -898,6 +902,7 @@ static unsigned int devkmsg_poll(struct file *file, poll_table *wait)
        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)
@@ -1284,6 +1289,7 @@ static int syslog_print(char __user *buf, int size)
                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;
@@ -1343,6 +1349,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
                return -ENOMEM;
 
        raw_spin_lock_irq(&logbuf_lock);
+       cont_flush();
        if (buf) {
                u64 next_seq;
                u64 seq;
@@ -1504,6 +1511,7 @@ int do_syslog(int type, char __user *buf, int len, int source)
        /* 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;
@@ -3016,6 +3024,7 @@ void kmsg_dump(enum kmsg_dump_reason reason)
                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;
@@ -3106,6 +3115,7 @@ bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
        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);
 
@@ -3148,6 +3158,7 @@ bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
                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;