Re: [PATCH v4 4/5] blktrace: break out of blktrace setup on concurrent calls
From: Bart Van Assche <bvanassche@acm.org>
Date: 2020-05-10 01:09:44
Also in:
linux-fsdevel, linux-mm, lkml
On 2020-05-08 20:10, Luis Chamberlain wrote:
quoted hunk ↗ jump to hunk
@@ -493,6 +496,12 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, */ strreplace(buts->name, '/', '_'); + 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;
Is this really sufficient? Shouldn't concurrent do_blk_trace_setup() calls that refer to the same request queue be serialized to really prevent that debugfs attribute creation fails? How about using the block device name instead of the partition name in the error message since the concurrency context is the block device and not the partition? Thanks, Bart.