From 15152e448b693fa41de40f1e40ffbe717a3aab88 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Fri, 20 Mar 2009 09:49:08 +0800 Subject: [PATCH] blktrace: report EBUSY correctly blk_trace_remove_queue() returns EINVAL if q->blk_trace == NULL, but blk_trace_setup_queue() doesn't return EBUSY if q->blk_trace != NULL. # echo 0 > sdaX/trace/enable # echo 0 > sdaX/trace/enable bash: echo: write error: Invalid argument # echo 1 > sdaX/trace/enable # echo 1 > sdaX/trace/enable (should return EBUSY) Signed-off-by: Li Zefan Acked-by: Arnaldo Carvalho de Melo Acked-by: Frederic Weisbecker Cc: Jens Axboe Cc: Steven Rostedt LKML-Reference: <49C2F614.2010101@cn.fujitsu.com> Signed-off-by: Ingo Molnar --- kernel/trace/blktrace.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 11e7c8d9d22..14986afdbc1 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1260,12 +1260,10 @@ static int blk_trace_remove_queue(struct request_queue *q) static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) { struct blk_trace *old_bt, *bt = NULL; - int ret; - ret = -ENOMEM; bt = kzalloc(sizeof(*bt), GFP_KERNEL); if (!bt) - goto err; + return -ENOMEM; bt->dev = dev; bt->act_mask = (u16)-1; @@ -1276,11 +1274,10 @@ static int blk_trace_setup_queue(struct request_queue *q, dev_t dev) if (old_bt != NULL) { (void)xchg(&q->blk_trace, old_bt); kfree(bt); - ret = -EBUSY; + return -EBUSY; } + return 0; -err: - return ret; } /* -- 2.41.1