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Date: Wed, 14 Nov 2012 00:13:03 +0100
From: Jan H. Schönherr <schnhrr@...tu-berlin.de>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: linux-kernel@...r.kernel.org, Kay Sievers <kay@...y.org>,
Jan H. Schönherr <schnhrr@...tu-berlin.de>
Subject: [PATCH 06/12] printk: reorganize storage of continuation buffer
Many fields of struct cont are similar to those in struct log.
Reorganize struct cont and embed a struct log in it. This allows us
to use regular struct log functions also for continuation records,
without having to create a copy first.
Signed-off-by: Jan H. Schönherr <schnhrr@...tu-berlin.de>
---
This is a prerequisite for the cont_print_text() rewrite.
An alternative would be to pass most of the struct log fields as
parameters to msg_print_text(): msg->text_len, msg->flags,
log_text(msg), msg->facility, msg->level, msg->ts_nsec. So that we can
use the function also with the continuation buffer.
---
kernel/printk.c | 69 ++++++++++++++++++++++++++++-----------------------------
1 file changed, 34 insertions(+), 35 deletions(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index 2939683..988a8f5 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1381,14 +1381,10 @@ static inline void printk_delay(void)
* reached the console in case of a kernel crash.
*/
static struct cont {
+ struct log msg;
char buf[LOG_LINE_MAX];
- size_t len; /* length == 0 means unused buffer */
size_t cons; /* bytes written to console */
struct task_struct *owner; /* task of first print*/
- u64 ts_nsec; /* time of first print */
- u8 level; /* log level of first message */
- u8 facility; /* log level of first message */
- enum log_flags flags; /* prefix, newline flags */
bool flushed:1; /* buffer sealed and committed */
} cont;
@@ -1396,10 +1392,10 @@ static void cont_flush(enum log_flags flags)
{
if (cont.flushed)
return;
- if (cont.len == 0)
+ if (cont.msg.text_len == 0)
return;
- cont.flags |= flags;
+ cont.msg.flags |= flags;
/*
* If a fragment of this line was directly flushed to the console, the
@@ -1407,17 +1403,17 @@ static void cont_flush(enum log_flags flags)
* duplicated output later -- see console_unlock().
*/
if (cont.cons)
- cont.flags |= LOG_NOCONS;
+ cont.msg.flags |= LOG_NOCONS;
- log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec, NULL, 0,
- cont.buf, cont.len);
+ log_store(cont.msg.facility, cont.msg.level, cont.msg.flags,
+ cont.msg.ts_nsec, NULL, 0, cont.buf, cont.msg.text_len);
/*
* If no fragment of this line ever reached the console or everything
* has been printed, free the buffer. Otherwise keep it available.
*/
- if (!cont.cons || cont.cons == cont.len)
- cont.len = 0;
+ if (!cont.cons || cont.cons == cont.msg.text_len)
+ cont.msg.text_len = 0;
else
cont.flushed = true;
}
@@ -1425,30 +1421,30 @@ static void cont_flush(enum log_flags flags)
static bool cont_add(int facility, int level, enum log_flags flags,
const char *text, size_t len)
{
- if (cont.len && cont.flushed)
+ if (cont.msg.text_len && cont.flushed)
return false;
- if (cont.len + len > sizeof(cont.buf)) {
+ if (cont.msg.text_len + len > sizeof(cont.buf)) {
/* the line gets too long, split it up in separate records */
cont_flush(0);
- if (cont.len)
+ if (cont.msg.text_len)
return false;
}
- if (!cont.len) {
- cont.facility = facility;
- cont.level = level;
+ if (!cont.msg.text_len) {
+ cont.msg.facility = facility;
+ cont.msg.level = level;
cont.owner = current;
- cont.ts_nsec = local_clock();
- cont.flags = flags;
+ cont.msg.ts_nsec = local_clock();
+ cont.msg.flags = flags;
cont.cons = 0;
cont.flushed = false;
}
- memcpy(cont.buf + cont.len, text, len);
- cont.len += len;
+ memcpy(cont.buf + cont.msg.text_len, text, len);
+ cont.msg.text_len += len;
- if (cont.len > (sizeof(cont.buf) * 80) / 100)
+ if (cont.msg.text_len > (sizeof(cont.buf) * 80) / 100)
cont_flush(0);
return true;
@@ -1460,27 +1456,27 @@ static size_t cont_print_text(char *text, size_t size)
size_t len;
if (cont.cons == 0 && (console_prev & LOG_NEWLINE ||
- cont.flags & LOG_PREFIX)) {
+ cont.msg.flags & LOG_PREFIX)) {
if (!(console_prev & LOG_NEWLINE))
text[textlen++] = '\n';
- textlen += print_time(cont.ts_nsec, text + textlen);
+ textlen += print_time(cont.msg.ts_nsec, text + textlen);
size -= textlen;
}
- len = cont.len - cont.cons;
+ len = cont.msg.text_len - cont.cons;
if (len > 0) {
if (len+1 > size)
len = size-1;
memcpy(text + textlen, cont.buf + cont.cons, len);
textlen += len;
- cont.cons = cont.len;
+ cont.cons = cont.msg.text_len;
}
if (cont.flushed) {
- if (cont.flags & LOG_NEWLINE)
+ if (cont.msg.flags & LOG_NEWLINE)
text[textlen++] = '\n';
/* got everything, release buffer */
- cont.len = 0;
+ cont.msg.text_len = 0;
}
return textlen;
}
@@ -1581,7 +1577,7 @@ asmlinkage int vprintk_emit(int facility, int level,
* Flush the conflicting buffer. An earlier newline was missing,
* or another task also prints continuation lines.
*/
- if (cont.len && !cont.flushed) {
+ if (cont.msg.text_len && !cont.flushed) {
if (cont.owner != current)
lflags |= LOG_PREFIX;
if (lflags & LOG_PREFIX)
@@ -1601,7 +1597,8 @@ asmlinkage int vprintk_emit(int facility, int level,
* there was a race with interrupts (prefix == true) then just
* flush it out and store this line separately.
*/
- if (cont.len && !cont.flushed && cont.owner == current) {
+ if (cont.msg.text_len && !cont.flushed &&
+ cont.owner == current) {
if (!(lflags & LOG_PREFIX))
stored = cont_add(facility, level, lflags,
text, text_len);
@@ -1711,9 +1708,11 @@ static u32 log_first_idx;
static u64 log_next_seq;
static enum log_flags console_prev;
static struct cont {
- size_t len;
+ struct {
+ size_t text_len;
+ u8 level;
+ } msg;
size_t cons;
- u8 level;
bool flushed:1;
} cont;
static struct log *log_from_idx(u32 idx) { return NULL; }
@@ -1999,7 +1998,7 @@ static void console_cont_flush(char *text, size_t size)
raw_spin_lock_irqsave(&logbuf_lock, flags);
- if (!cont.len)
+ if (!cont.msg.text_len)
goto out;
/*
@@ -2013,7 +2012,7 @@ static void console_cont_flush(char *text, size_t size)
len = cont_print_text(text, size);
raw_spin_unlock(&logbuf_lock);
stop_critical_timings();
- call_console_drivers(cont.level, text, len);
+ call_console_drivers(cont.msg.level, text, len);
start_critical_timings();
local_irq_restore(flags);
return;
--
1.8.0.316.g291341c.dirty
--
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