btrfs: Add ratelimit to btrfs printing
This patch adds ratelimiting to all messages which are not using the _rl
version of the various printing APIs in btrfs. This is designed to be
used as a safety net, since a flood messages might cause the softlockup
detector to trigger. To reduce interference between different classes of
messages use a separate ratelimit state for every class of message.
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 60e7179..8766d56 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -184,6 +184,22 @@
"debug",
};
+
+/*
+ * Use one ratelimit state per log level so that a flood of less important
+ * messages doesn't cause more important ones to be dropped.
+ */
+static struct ratelimit_state printk_limits[] = {
+ RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100),
+ RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100),
+};
+
void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
{
struct super_block *sb = fs_info->sb;
@@ -192,6 +208,7 @@
va_list args;
const char *type = logtypes[4];
int kern_level;
+ struct ratelimit_state *ratelimit;
va_start(args, fmt);
@@ -202,13 +219,18 @@
lvl[size] = '\0';
fmt += size;
type = logtypes[kern_level - '0'];
- } else
+ ratelimit = &printk_limits[kern_level - '0'];
+ } else {
*lvl = '\0';
+ /* Default to debug output */
+ ratelimit = &printk_limits[7];
+ }
vaf.fmt = fmt;
vaf.va = &args;
- printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
+ if (__ratelimit(ratelimit))
+ printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
va_end(args);
}