Re: [PATCH 1/2] block: make __register_blkdev() return an error

On Sat, Sep 04, 2021 at 11:49:06AM +0900, Tetsuo Handa wrote:

On 2021/09/04 10:39, Luis Chamberlain wrote:

quoted

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 45df6cbccf12..81a4738910a8 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c

@@ -1144,10 +1144,13 @@ struct block_device *blkdev_get_no_open(dev_t dev)
 {
 	struct block_device *bdev;
 	struct inode *inode;
+	int ret;
 
 	inode = ilookup(blockdev_superblock, dev);
 	if (!inode) {
-		blk_request_module(dev);
+		ret = blk_request_module(dev);
+		if (ret)
+			return NULL;

Since e.g. loop_add() from loop_probe() returns -EEXIST when /dev/loop$num already
exists (e.g. raced with ioctl(LOOP_CTL_ADD)), isn't unconditionally failing an over-failing?

It's not clear to me how. What do we loose by capturing the failure on
blk_request_module()?

  Luis