@@ -4810,7 +4810,7 @@ static int add_tree_backref(struct cache_tree *extent_cache, u64 bytenr,
static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
u64 parent, u64 root, u64 owner, u64 offset,
- u32 num_refs, int found_ref, u64 max_size)
+ u32 num_refs, u64 gen, int found_ref, u64 max_size)
{
struct extent_record *rec;
struct data_backref *back;
@@ -4826,6 +4826,7 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
tmpl.start = bytenr;
tmpl.nr = 1;
tmpl.max_size = max_size;
+ tmpl.generation = gen;
ret = add_extent_rec_nolookup(extent_cache, &tmpl);
if (ret)
@@ -4840,6 +4841,8 @@ static int add_data_backref(struct cache_tree *extent_cache, u64 bytenr,
if (rec->max_size < max_size)
rec->max_size = max_size;
+ if (rec->generation < gen)
+ rec->generation = gen;
/*
* If found_ref is set then max_size is the real size and must match the
* existing refs. So if we have already found a ref then we need to
@@ -5315,6 +5318,7 @@ static int process_extent_item(struct btrfs_root *root,
u64 refs = 0;
u64 offset;
u64 num_bytes;
+ u64 gen;
int metadata = 0;
btrfs_item_key_to_cpu(eb, &key, slot);
@@ -5340,6 +5344,7 @@ static int process_extent_item(struct btrfs_root *root,
ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);
refs = btrfs_extent_refs(eb, ei);
+ gen = btrfs_extent_generation(eb, ei);
if (btrfs_extent_flags(eb, ei) & BTRFS_EXTENT_FLAG_TREE_BLOCK)
metadata = 1;
else
@@ -5362,6 +5367,7 @@ static int process_extent_item(struct btrfs_root *root,
tmpl.metadata = metadata;
tmpl.found_rec = 1;
tmpl.max_size = num_bytes;
+ tmpl.generation = gen;
add_extent_rec(extent_cache, &tmpl);
ptr = (unsigned long)(ei + 1);
@@ -5401,14 +5407,14 @@ static int process_extent_item(struct btrfs_root *root,
dref),
btrfs_extent_data_ref_offset(eb, dref),
btrfs_extent_data_ref_count(eb, dref),
- 0, num_bytes);
+ gen, 0, num_bytes);
break;
case BTRFS_SHARED_DATA_REF_KEY:
sref = (struct btrfs_shared_data_ref *)(iref + 1);
add_data_backref(extent_cache, key.objectid, offset,
0, 0, 0,
btrfs_shared_data_ref_count(eb, sref),
- 0, num_bytes);
+ gen, 0, num_bytes);
break;
default:
fprintf(stderr,
@@ -6352,7 +6358,7 @@ static int run_next_block(struct btrfs_root *root,
ref),
btrfs_extent_data_ref_offset(buf, ref),
btrfs_extent_data_ref_count(buf, ref),
- 0, root->fs_info->sectorsize);
+ 0, 0, root->fs_info->sectorsize);
continue;
}
if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
@@ -6363,7 +6369,7 @@ static int run_next_block(struct btrfs_root *root,
add_data_backref(extent_cache,
key.objectid, key.offset, 0, 0, 0,
btrfs_shared_data_ref_count(buf, ref),
- 0, root->fs_info->sectorsize);
+ 0, 0, root->fs_info->sectorsize);
continue;
}
if (key.type == BTRFS_ORPHAN_ITEM_KEY) {
@@ -6403,7 +6409,8 @@ static int run_next_block(struct btrfs_root *root,
add_data_backref(extent_cache,
btrfs_file_extent_disk_bytenr(buf, fi),
parent, owner, key.objectid, key.offset -
- btrfs_file_extent_offset(buf, fi), 1, 1,
+ btrfs_file_extent_offset(buf, fi), 1,
+ btrfs_file_extent_generation(buf, fi), 1,
btrfs_file_extent_disk_num_bytes(buf, fi));
}
} else {
@@ -6706,7 +6713,10 @@ static int record_extent(struct btrfs_trans_handle *trans,
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, ei, 0);
- btrfs_set_extent_generation(leaf, ei, rec->generation);
+ if (rec->generation)
+ btrfs_set_extent_generation(leaf, ei, rec->generation);
+ else
+ btrfs_set_extent_generation(leaf, ei, trans->transid);
if (back->is_data) {
btrfs_set_extent_flags(leaf, ei,
[BUG] When using `btrfs check --init-extent-tree`, we will create incorrect generation number for data extents in extent tree: item 10 key (13631488 EXTENT_ITEM 1048576) itemoff 15828 itemsize 53 refs 1 gen 0 flags DATA extent data backref root FS_TREE objectid 257 offset 0 count 1 [CAUSE] Since data extent generation is not as obvious as tree blocks, which has header containing its generations, so for data extents, its extent_record::generation is not really updated, resulting such 0 generation. [FIX] To get generation of a data extent, there are two sources we can rely: - EXTENT_ITEM There is always a btrfs_extent_item::generation can be utilized. Although this is not possible for --init-extent-tree use case. - EXTENT_DATA We have btrfs_file_extent_item::generation for regular and preallocated data extents. Since --init-extent-tree will go through subvolume trees, this would be the main source for extent data generation. Then we only need to make add_data_backref() to accept @gen parameter, and pass it down to extent_record structure. And for the final extent item generation update, here we add extra fallback values, if we can't find FILE_EXTENT items. In that case, we just fall back to current transid. With this modification, recreated data EXTENT_ITEM now has correct generation number: item 10 key (13631488 EXTENT_ITEM 1048576) itemoff 15828 itemsize 53 refs 1 gen 6 flags DATA extent data backref root FS_TREE objectid 257 offset 0 count 1 Signed-off-by: Qu Wenruo <wqu@suse.com> --- check/main.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-)