Commit 4f4ee2bf authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Song Liu
Browse files

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: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarSong Liu <song@kernel.org>
parent 9aeb7f99

drivers/md/raid5-ppl.c

+10 −3
Original line number Diff line number Diff line
@@ -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);