[PATCH] md/raid10: fix: incompatible types in comparison expression (different address spaces).

From: YANG LI
Date: Tue Dec 22 2020 - 03:03:03 EST


Fixes the following sparse errors in drivers/md/raid10.c error:
incompatible types in comparison expression (different address spaces).

The error was because of the following line in function read_balance():

rdev = rcu_dereference(conf->mirrors[disk].replacement);
if (rdev == NULL || test_bit(Faulty, &rdev->flags) ||
r10_bio->devs[slot].addr + sectors > rdev->recovery_offset)
rdev = rcu_dereference(conf->mirrors[disk].rdev);

Annotating the struct md_rdev *rdev and *replacement in
drivers/md/raid10.h with __rcu fixes the sparse error.

Signed-off-by: YANG LI <abaci-bugfix@xxxxxxxxxxxxxxxxx>
Reported-by: Abaci <abaci@xxxxxxxxxxxxxxxxx>
---
drivers/md/raid10.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h
index 79cd2b7..910bd5f 100644
--- a/drivers/md/raid10.h
+++ b/drivers/md/raid10.h
@@ -16,7 +16,8 @@
*/

struct raid10_info {
- struct md_rdev *rdev, *replacement;
+ struct md_rdev __rcu *rdev;
+ struct md_rdev __rcu *replacement;
sector_t head_position;
int recovery_disabled; /* matches
* mddev->recovery_disabled
--
1.8.3.1