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authorPetr Mladek <pmladek@suse.com>2016-12-12 16:45:50 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 18:55:09 -0800
commit262c5e86fec7cfd59754732001a9ff5b13eba501 (patch)
tree7ec12f40e1f202e6c488949eb3ed7026a61b3fc1
parent497957576cf8a2150d723aedd74ea60b5d498bfe (diff)
printk/btrfs: handle more message headers
Commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") allows to define more message headers for a single message. The motivation is that continuous lines might get mixed. Therefore it make sense to define the right log level for every piece of a cont line. The current btrfs_printk() macros do not support continuous lines at the moment. But better be prepared for a custom messages and avoid potential "lvl" buffer overflow. This patch iterates over the entire message header. It is interested only into the message level like the original code. This patch also introduces PRINTK_MAX_SINGLE_HEADER_LEN. Three bytes are enough for the message level header at the moment. But it used to be three, see the commit 04d2c8c83d0e ("printk: convert the format for KERN_<LEVEL> to a 2 byte pattern"). Also I fixed the default ratelimit level. It looked very strange when it was different from the default log level. [pmladek@suse.com: Fix a check of the valid message level] Link: http://lkml.kernel.org/r/20161111183236.GD2145@dhcp128.suse.cz Link: http://lkml.kernel.org/r/1478695291-12169-4-git-send-email-pmladek@suse.com Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: David Sterba <dsterba@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <jbacik@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/btrfs/super.c26
-rw-r--r--include/linux/printk.h2
2 files changed, 17 insertions, 11 deletions
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 74ed5aae6cea..180f910339f4 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -202,27 +202,31 @@ static struct ratelimit_state printk_limits[] = {
void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
{
struct super_block *sb = fs_info->sb;
- char lvl[4];
+ char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1];
struct va_format vaf;
va_list args;
- const char *type = logtypes[4];
+ const char *type = NULL;
int kern_level;
struct ratelimit_state *ratelimit;
va_start(args, fmt);
- kern_level = printk_get_level(fmt);
- if (kern_level) {
+ while ((kern_level = printk_get_level(fmt)) != 0) {
size_t size = printk_skip_level(fmt) - fmt;
- memcpy(lvl, fmt, size);
- lvl[size] = '\0';
+
+ if (kern_level >= '0' && kern_level <= '7') {
+ memcpy(lvl, fmt, size);
+ lvl[size] = '\0';
+ type = logtypes[kern_level - '0'];
+ ratelimit = &printk_limits[kern_level - '0'];
+ }
fmt += size;
- type = logtypes[kern_level - '0'];
- ratelimit = &printk_limits[kern_level - '0'];
- } else {
+ }
+
+ if (!type) {
*lvl = '\0';
- /* Default to debug output */
- ratelimit = &printk_limits[7];
+ type = logtypes[4];
+ ratelimit = &printk_limits[4];
}
vaf.fmt = fmt;
diff --git a/include/linux/printk.h b/include/linux/printk.h
index a0859e169bc3..afe8ccec1672 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -10,6 +10,8 @@
extern const char linux_banner[];
extern const char linux_proc_banner[];
+#define PRINTK_MAX_SINGLE_HEADER_LEN 2
+
static inline int printk_get_level(const char *buffer)
{
if (buffer[0] == KERN_SOH_ASCII && buffer[1]) {