From 35f4e5e6f198a11c11606a742b309aa80271c66d Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Wed, 13 Jul 2016 16:19:15 +0300 Subject: [PATCH] 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 Signed-off-by: David Sterba --- fs/btrfs/super.c | 26 ++++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 60e7179ed4b7..8766d560a48f 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -184,6 +184,22 @@ static const char * const logtypes[] = { "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 @@ void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) va_list args; const char *type = logtypes[4]; int kern_level; + struct ratelimit_state *ratelimit; va_start(args, fmt); @@ -202,13 +219,18 @@ void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) 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); }