[PATCH 6.6 019/567] btrfs: read raid stripe tree from disk

Greg Kroah-Hartman
2026-03-23T14:52:25Z

6.6-stable review patch. If anyone has any objections, please let me know.

------------------

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

[ Upstream commit 515020900d447796bc2f0f57064663617a11b65d ]

If we find the raid-stripe-tree on mount, read it from disk. This is
a backward incompatible feature. The rescue=ignorebadroots mount option
will skip this tree.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 511dc8912ae3 ("btrfs: fix incorrect key offset in error message in check_dev_extent_item()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/btrfs/block-rsv.c | 6 ++++++
fs/btrfs/disk-io.c | 18 ++++++++++++++++++
fs/btrfs/fs.h | 1 +
include/uapi/linux/btrfs.h | 1 +
4 files changed, 26 insertions(+)

diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c
index 97084ea3af0cc..07bf07431a7f4 100644
--- a/fs/btrfs/block-rsv.c
+++ b/fs/btrfs/block-rsv.c
@@ -354,6 +354,11 @@ void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info)
min_items++;
}

+ if (btrfs_fs_incompat(fs_info, RAID_STRIPE_TREE)) {
+ num_bytes += btrfs_root_used(&fs_info->stripe_root->root_item);
+ min_items++;
+ }
+
/*
* But we also want to reserve enough space so we can do the fallback
* global reserve for an unlink, which is an additional
@@ -405,6 +410,7 @@ void btrfs_init_root_block_rsv(struct btrfs_root *root)
case BTRFS_EXTENT_TREE_OBJECTID:
case BTRFS_FREE_SPACE_TREE_OBJECTID:
case BTRFS_BLOCK_GROUP_TREE_OBJECTID:
+ case BTRFS_RAID_STRIPE_TREE_OBJECTID:
root->block_rsv = &fs_info->delayed_refs_rsv;
break;
case BTRFS_ROOT_TREE_OBJECTID:
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3c26e91a8055f..89e98f9cc2026 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1179,6 +1179,8 @@ static struct btrfs_root *btrfs_get_global_root(struct btrfs_fs_info *fs_info,
return btrfs_grab_root(fs_info->block_group_root);
case BTRFS_FREE_SPACE_TREE_OBJECTID:
return btrfs_grab_root(btrfs_global_root(fs_info, &key));
+ case BTRFS_RAID_STRIPE_TREE_OBJECTID:
+ return btrfs_grab_root(fs_info->stripe_root);
default:
return NULL;
}
@@ -1259,6 +1261,7 @@ void btrfs_free_fs_info(struct btrfs_fs_info *fs_info)
btrfs_put_root(fs_info->fs_root);
btrfs_put_root(fs_info->data_reloc_root);
btrfs_put_root(fs_info->block_group_root);
+ btrfs_put_root(fs_info->stripe_root);
btrfs_check_leaked_roots(fs_info);
btrfs_extent_buffer_leak_debug_check(fs_info);
kfree(fs_info->super_copy);
@@ -1812,6 +1815,7 @@ static void free_root_pointers(struct btrfs_fs_info *info, bool free_chunk_root)
free_root_extent_buffers(info->fs_root);
free_root_extent_buffers(info->data_reloc_root);
free_root_extent_buffers(info->block_group_root);
+ free_root_extent_buffers(info->stripe_root);
if (free_chunk_root)
free_root_extent_buffers(info->chunk_root);
}
@@ -2287,6 +2291,20 @@ static int btrfs_read_roots(struct btrfs_fs_info *fs_info)
fs_info->uuid_root = root;
}

+ if (btrfs_fs_incompat(fs_info, RAID_STRIPE_TREE)) {
+ location.objectid = BTRFS_RAID_STRIPE_TREE_OBJECTID;
+ root = btrfs_read_tree_root(tree_root, &location);
+ if (IS_ERR(root)) {
+ if (!btrfs_test_opt(fs_info, IGNOREBADROOTS)) {
+ ret = PTR_ERR(root);
+ goto out;
+ }
+ } else {
+ set_bit(BTRFS_ROOT_TRACK_DIRTY, &root->state);
+ fs_info->stripe_root = root;
+ }
+ }
+
return 0;
out:
btrfs_warn(fs_info, "failed to read root (objectid=%llu): %d",
diff --git a/fs/btrfs/fs.h b/fs/btrfs/fs.h
index d24d41f7811a6..b8b9ce8921baf 100644
--- a/fs/btrfs/fs.h
+++ b/fs/btrfs/fs.h
@@ -371,6 +371,7 @@ struct btrfs_fs_info {
struct btrfs_root *uuid_root;
struct btrfs_root *data_reloc_root;
struct btrfs_root *block_group_root;
+ struct btrfs_root *stripe_root;

/* The log root tree is a directory of all the other log roots */
struct btrfs_root *log_root_tree;
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 6f776faaa791c..7b499b90bb779 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -333,6 +333,7 @@ struct btrfs_ioctl_fs_info_args {
#define BTRFS_FEATURE_INCOMPAT_RAID1C34 (1ULL << 11)
#define BTRFS_FEATURE_INCOMPAT_ZONED (1ULL << 12)
#define BTRFS_FEATURE_INCOMPAT_EXTENT_TREE_V2 (1ULL << 13)
+#define BTRFS_FEATURE_INCOMPAT_RAID_STRIPE_TREE (1ULL << 14)

struct btrfs_ioctl_feature_flags {
__u64 compat_flags;
--
2.51.0