From: Ming Lei <ming.lei@redhat.com>
Date: Thu, 28 Nov 2024 12:50:26 +0000 (+0800)
Subject: blktrace: don't centralize grabbing q->debugfs_mutex in blk_trace_ioctl
X-Git-Tag: for-6.14/block-20250118~70
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=fd9b0244f5c5f63461ca9752eebd2423ae02bb59;p=linux-block.git

blktrace: don't centralize grabbing q->debugfs_mutex in blk_trace_ioctl

Call each handler directly and the handler do grab q->debugfs_mutex,
prepare for killing dependency between ->debug_mutex and ->mmap_lock.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241128125029.4152292-2-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 8fd292d34d89..f01aae3a2f7b 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -732,34 +732,32 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg)
 	int ret, start = 0;
 	char b[BDEVNAME_SIZE];
 
-	mutex_lock(&q->debugfs_mutex);
-
 	switch (cmd) {
 	case BLKTRACESETUP:
 		snprintf(b, sizeof(b), "%pg", bdev);
-		ret = __blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
+		ret = blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
 		break;
 #if defined(CONFIG_COMPAT) && defined(CONFIG_X86_64)
 	case BLKTRACESETUP32:
 		snprintf(b, sizeof(b), "%pg", bdev);
+		mutex_lock(&q->debugfs_mutex);
 		ret = compat_blk_trace_setup(q, b, bdev->bd_dev, bdev, arg);
+		mutex_unlock(&q->debugfs_mutex);
 		break;
 #endif
 	case BLKTRACESTART:
 		start = 1;
 		fallthrough;
 	case BLKTRACESTOP:
-		ret = __blk_trace_startstop(q, start);
+		ret = blk_trace_startstop(q, start);
 		break;
 	case BLKTRACETEARDOWN:
-		ret = __blk_trace_remove(q);
+		ret = blk_trace_remove(q);
 		break;
 	default:
 		ret = -ENOTTY;
 		break;
 	}
-
-	mutex_unlock(&q->debugfs_mutex);
 	return ret;
 }