Commit e1a41324 authored by Liu Bo's avatar Liu Bo Committed by Jens Axboe
Browse files

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: default avatarLiu Bo <bo.liu@linux.alibaba.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1954e9a9

kernel/trace/blktrace.c

+3 −3
Original line number Diff line number Diff line
@@ -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);