diff options
Diffstat (limited to 'kernel/trace/blktrace.c')
| -rw-r--r-- | kernel/trace/blktrace.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index b7e1e09a0bef..7a4ca2deb39b 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -3,6 +3,9 @@ * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk> * */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include <linux/kernel.h> #include <linux/blkdev.h> #include <linux/blktrace_api.h> @@ -495,6 +498,16 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, */ strreplace(buts->name, '/', '_'); + /* + * bdev can be NULL, as with scsi-generic, this is a helpful as + * we can be. + */ + if (q->blk_trace) { + pr_warn("Concurrent blktraces are not allowed on %s\n", + buts->name); + return -EBUSY; + } + bt = kzalloc(sizeof(*bt), GFP_KERNEL); if (!bt) return -ENOMEM; |