From e1a413245a564683697a3d02ec197b72cf009b89 Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 29 Jun 2018 09:56:08 +0800 Subject: [PATCH] Blktrace: bail out early if block debugfs is not configured Since @blk_debugfs_root couldn't be configured dynamically, we can save a few memory allocation if it's not there. Signed-off-by: Liu Bo Signed-off-by: Jens Axboe --- kernel/trace/blktrace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 987d9a9ae283..b951aa1fac61 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -494,6 +494,9 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, if (!buts->buf_size || !buts->buf_nr) return -EINVAL; + if (!blk_debugfs_root) + return -ENOENT; + strncpy(buts->name, name, BLKTRACE_BDEV_SIZE); buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0'; @@ -518,9 +521,6 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, ret = -ENOENT; - if (!blk_debugfs_root) - goto err; - dir = debugfs_lookup(buts->name, blk_debugfs_root); if (!dir) bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);