From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Date: Mon, 8 Jul 2024 11:24:08 +0000 (+0200)
Subject: btrfs: update stripe extents for existing logical addresses
X-Git-Tag: v6.12-rc1~207^2~109
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=8c4cba2adbb0ec63f3833cad7452a431580e9ffa;p=thirdparty%2Fkernel%2Flinux.git

btrfs: update stripe extents for existing logical addresses

Update a stripe extent in case of an already existing logical address,
but with different physical addresses and/or device id instead of
bailing out with EEXIST.

This can happen i.e. in case of a device replace operation, where data
extents get rewritten to a new disk.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/raid-stripe-tree.c b/fs/btrfs/raid-stripe-tree.c
index e6f7a234b8f68..0c7b928805e5e 100644
--- a/fs/btrfs/raid-stripe-tree.c
+++ b/fs/btrfs/raid-stripe-tree.c
@@ -73,6 +73,36 @@ int btrfs_delete_raid_extent(struct btrfs_trans_handle *trans, u64 start, u64 le
 	return ret;
 }
 
+static int update_raid_extent_item(struct btrfs_trans_handle *trans,
+				   struct btrfs_key *key,
+				   struct btrfs_stripe_extent *stripe_extent,
+				   const size_t item_size)
+{
+	struct btrfs_path *path;
+	struct extent_buffer *leaf;
+	int ret;
+	int slot;
+
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	ret = btrfs_search_slot(trans, trans->fs_info->stripe_root, key, path,
+				0, 1);
+	if (ret)
+		return (ret == 1 ? ret : -EINVAL);
+
+	leaf = path->nodes[0];
+	slot = path->slots[0];
+
+	write_extent_buffer(leaf, stripe_extent, btrfs_item_ptr_offset(leaf, slot),
+			    item_size);
+	btrfs_mark_buffer_dirty(trans, leaf);
+	btrfs_free_path(path);
+
+	return ret;
+}
+
 static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
 					struct btrfs_io_context *bioc)
 {
@@ -112,6 +142,9 @@ static int btrfs_insert_one_raid_extent(struct btrfs_trans_handle *trans,
 
 	ret = btrfs_insert_item(trans, stripe_root, &stripe_key, stripe_extent,
 				item_size);
+	if (ret == -EEXIST)
+		ret = update_raid_extent_item(trans, &stripe_key, stripe_extent,
+					      item_size);
 	if (ret)
 		btrfs_abort_transaction(trans, ret);