To suppress the last remaining sparse warnings about accessing
rdev, add rcu_dereference_protected calls to a couple places
in raid5-ppl. All of these places are called under raid5_run and
therefore are occurring before the array has started and is thus
safe.
There's no sensible check to do for the second argument of
rcu_dereference_protected() so a comment is added instead.
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
---
drivers/md/raid5-ppl.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/md/raid5-ppl.c b/drivers/md/raid5-ppl.c
index d3962d92df18..55d065a87b89 100644
--- a/drivers/md/raid5-ppl.c
+++ b/drivers/md/raid5-ppl.c
@@ -883,7 +883,9 @@ static int ppl_recover_entry(struct ppl_log *log, struct ppl_header_entry *e,
(unsigned long long)r_sector, dd_idx,
(unsigned long long)sector);
- rdev = conf->disks[dd_idx].rdev;
+ /* Array has not started so rcu dereference is safe */
+ rdev = rcu_dereference_protected(
+ conf->disks[dd_idx].rdev, 1);
if (!rdev || (!test_bit(In_sync, &rdev->flags) &&
sector >= rdev->recovery_offset)) {
pr_debug("%s:%*s data member disk %d missing\n",
@@ -934,7 +936,10 @@ static int ppl_recover_entry(struct ppl_log *log, struct ppl_header_entry *e,
parity_sector = raid5_compute_sector(conf, r_sector_first + i,
0, &disk, &sh);
BUG_ON(sh.pd_idx != le32_to_cpu(e->parity_disk));
- parity_rdev = conf->disks[sh.pd_idx].rdev;
+
+ /* Array has not started so rcu dereference is safe */
+ parity_rdev = rcu_dereference_protected(
+ conf->disks[sh.pd_idx].rdev, 1);
BUG_ON(parity_rdev->bdev->bd_dev != log->rdev->bdev->bd_dev);
pr_debug("%s:%*s write parity at sector %llu, disk %s\n",
@@ -1404,7 +1409,9 @@ int ppl_init_log(struct r5conf *conf)
for (i = 0; i < ppl_conf->count; i++) {
struct ppl_log *log = &ppl_conf->child_logs[i];
- struct md_rdev *rdev = conf->disks[i].rdev;
+ /* Array has not started so rcu dereference is safe */
+ struct md_rdev *rdev =
+ rcu_dereference_protected(conf->disks[i].rdev, 1);
mutex_init(&log->io_mutex);
spin_lock_init(&log->io_list_lock);
--
2.30.2
