[PATCH v3 3/5] xen/blkfront: reorder tests in xlblk_init()

From: Juergen Gross
Date: Mon Aug 13 2018 - 10:01:48 EST


In case we don't want pv block devices we should not test parameters
for sanity and eventually print out error messages. So test precluding
conditions before checking parameters.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx>
---
drivers/block/xen-blkfront.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 7c4b1b9d3971..36e4ca41e765 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -2713,6 +2713,15 @@ static int __init xlblk_init(void)
if (!xen_domain())
return -ENODEV;

+ if (!xen_has_pv_disk_devices())
+ return -ENODEV;
+
+ if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) {
+ pr_warn("xen_blk: can't get major %d with name %s\n",
+ XENVBD_MAJOR, DEV_NAME);
+ return -ENODEV;
+ }
+
if (xen_blkif_max_segments < BLKIF_MAX_SEGMENTS_PER_REQUEST)
xen_blkif_max_segments = BLKIF_MAX_SEGMENTS_PER_REQUEST;

@@ -2728,15 +2737,6 @@ static int __init xlblk_init(void)
xen_blkif_max_queues = nr_cpus;
}

- if (!xen_has_pv_disk_devices())
- return -ENODEV;
-
- if (register_blkdev(XENVBD_MAJOR, DEV_NAME)) {
- printk(KERN_WARNING "xen_blk: can't get major %d with name %s\n",
- XENVBD_MAJOR, DEV_NAME);
- return -ENODEV;
- }
-
INIT_DELAYED_WORK(&blkfront_work, blkfront_delay_work);

ret = xenbus_register_frontend(&blkfront_driver);
--
2.13.7