[PATCH v3] btrfs: zoned: use zone aware sb location for scrub

[Johannes Thumshirn <jth@kernel.org>]

At the moment scrub_supers() doesn't grab the super block's location via
the zoned device aware btrfs_sb_log_location() but via btrfs_sb_offset().

This leads to checksum errors on 'scrub' as we're not accessing the
correct location of the super block.

So use btrfs_sb_log_location() for getting the super blocks location on
scrub.

Reported-by: WA AM <waautomata@gmail.com>
Cc: Qu Wenru <wqu@suse.com>
Link: http://lore.kernel.org/linux-btrfs/CANU2Z0EvUzfYxczLgGUiREoMndE9WdQnbaawV5Fv5gNXptPUKw@mail.gmail.com
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
Changes to v2:
- Handle -ENOENT return from btrfs_sb_log_location
Link to v2:
- https://lore.kernel.org/linux-btrfs/75f3da872a8c1094ef0f6ed93aac9bf774ef895b.1709554485.git.jth@kernel.org
Changes to v1:
- Increase super_errors
- Don't break out after 1st error
Link to v1:
- https://lore.kernel.org/linux-btrfs/933562c5bf37ad3e03f1a6b2ab5a9eb741ee0192.1709206779.git.johannes.thumshirn@wdc.com
---
 fs/btrfs/scrub.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index c4bd0e60db59..fa25004ab04e 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -2812,7 +2812,17 @@ static noinline_for_stack int scrub_supers(struct scrub_ctx *sctx,
 		gen = btrfs_get_last_trans_committed(fs_info);
 
 	for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
-		bytenr = btrfs_sb_offset(i);
+		ret = btrfs_sb_log_location(scrub_dev, i, 0, &bytenr);
+		if (ret == -ENOENT)
+			break;
+
+		if (ret) {
+			spin_lock(&sctx->stat_lock);
+			sctx->stat.super_errors++;
+			spin_unlock(&sctx->stat_lock);
+			continue;
+		}
+
 		if (bytenr + BTRFS_SUPER_INFO_SIZE >
 		    scrub_dev->commit_total_bytes)
 			break;
-- 
2.35.3