From 4f4ee2bf32860e4aa3b07be3fc9224fbe6cce4fe Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Thu, 7 Apr 2022 10:57:12 -0600 Subject: md/raid5-ppl: Annotate with rcu_dereference_protected() 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 Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu --- drivers/md/raid5-ppl.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'drivers') 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); -- cgit v1.2.3