diff options
| author | Liu Bo <bo.liu@linux.alibaba.com> | 2018-06-29 09:56:08 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-11-10 10:29:02 +0100 |
| commit | 595290ccd13a8af9463a02b447860ca12b4e3254 (patch) | |
| tree | 45b84aa02d9fe8852a5a1a37fd2fdbe5f342cbb9 /kernel | |
| parent | 4592235990566fc74d364f54f6e77ee5d4b443f9 (diff) | |
Blktrace: bail out early if block debugfs is not configured
commit e1a413245a564683697a3d02ec197b72cf009b89 upstream.
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 <bo.liu@linux.alibaba.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[bwh: Cherry-picked for 4.14 to ease backporting a later fix]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/blktrace.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 987daf9cc6e5..38e0b97eede6 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -498,6 +498,9 @@ 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'; @@ -532,9 +535,6 @@ 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); |