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authorOmar Sandoval <osandov@fb.com>2017-01-31 14:53:22 -0800
committerJens Axboe <axboe@fb.com>2017-02-02 10:20:16 -0700
commit6ac93117ab009d3901ed5d3d0f79056eb5fc0afd (patch)
tree1f5e064f9ecbbd55d8d72a23a4f3b7f66d411384 /kernel/trace/blktrace.c
parent62ebce16c0ac2ffac44e32f931a2d8f6e749be4c (diff)
downloadlinux-6ac93117ab009d3901ed5d3d0f79056eb5fc0afd.tar.bz2
blktrace: use existing disk debugfs directory
We may already have a directory to put the blktrace stuff in if 1. The disk uses blk-mq 2. CONFIG_BLK_DEBUG_FS is enabled 3. We are tracing the whole disk and not a partition Instead of hardcoding this very specific case, let's use the new debugfs_lookup(). If the directory exists, we use it, otherwise we create one and clean it up later. Fixes: 07e4fead45e6 ("blk-mq: create debugfs directory tree") Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'kernel/trace/blktrace.c')
-rw-r--r--kernel/trace/blktrace.c13
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 8cea91d248d9..b2058a7f94bd 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -470,12 +470,12 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
if (!blk_debugfs_root)
goto err;
- dir = debugfs_create_dir(buts->name, blk_debugfs_root);
-
+ dir = debugfs_lookup(buts->name, blk_debugfs_root);
+ if (!dir)
+ bt->dir = dir = debugfs_create_dir(buts->name, blk_debugfs_root);
if (!dir)
goto err;
- bt->dir = dir;
bt->dev = dev;
atomic_set(&bt->dropped, 0);
INIT_LIST_HEAD(&bt->running_list);
@@ -517,9 +517,12 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();
- return 0;
+ ret = 0;
err:
- blk_trace_free(bt);
+ if (dir && !bt->dir)
+ dput(dir);
+ if (ret)
+ blk_trace_free(bt);
return ret;
}