Commit
854437ca(btrfs-progs: extent-tree: avoid allocating tree block
that crosses stripe boundary) introduces check for logical bytenr not
crossing stripe boundary.
However that check is not completely correct.
It only checks if the logical bytenr and length agaist absolute logical
offset.
That's to say, it only check if a tree block lies in 64K logical stripe.
But in fact, it's possible a block group starts at bytenr unaligned with
64K, just like the following case.
Then btrfsck will give false alert.
0 32K 64K 96K 128K 160K ...
|--------------- Block group A ---------------------
|<-----TB 32K------>|
|/Scrub stripe unit/|
| WRONG UNIT |
In that case, TB(tree block) at bytenr 32K in fact fits into the kernel
scrub stripe unit.
But doesn't fit into the pure logical 64K stripe.
Fix check_crossing_stripes() to compare bytenr to block group start, not
to absolute logical bytenr.
Reported-by: Jussi Kansanen <jussi.kansanen@gmail.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
bytes_used += rec->nr;
if (tmpl->metadata)
- rec->crossing_stripes = check_crossing_stripes(rec->start,
- global_info->tree_root->nodesize);
+ rec->crossing_stripes = check_crossing_stripes(global_info,
+ rec->start, global_info->tree_root->nodesize);
check_extent_type(rec);
return ret;
}
*/
if (tmpl->metadata)
rec->crossing_stripes = check_crossing_stripes(
- rec->start, global_info->tree_root->nodesize);
+ global_info, rec->start,
+ global_info->tree_root->nodesize);
check_extent_type(rec);
maybe_free_extent_rec(extent_cache, rec);
return ret;
if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)
metadata = 1;
- if (metadata && check_crossing_stripes(key.objectid, eb->len)) {
+ if (metadata && check_crossing_stripes(global_info, key.objectid,
+ eb->len)) {
error("bad metadata [%llu, %llu) crossing stripe boundary",
key.objectid, key.objectid + nodesize);
err |= CROSSING_STRIPE_BOUNDARY;
}
if (!(data & BTRFS_BLOCK_GROUP_DATA)) {
- if (check_crossing_stripes(ins->objectid, num_bytes)) {
- search_start = round_down(ins->objectid + num_bytes,
- BTRFS_STRIPE_LEN);
+ if (check_crossing_stripes(info, ins->objectid, num_bytes)) {
+ struct btrfs_block_group_cache *bg_cache;
+ u64 bg_offset;
+
+ bg_cache = btrfs_lookup_block_group(info, ins->objectid);
+ if (!bg_cache)
+ goto no_bg_cache;
+ bg_offset = ins->objectid - bg_cache->key.objectid;
+
+ search_start = round_up(bg_offset + num_bytes,
+ BTRFS_STRIPE_LEN) + bg_offset;
goto new_group;
}
+no_bg_cache:
block_group = btrfs_lookup_block_group(info, ins->objectid);
if (block_group)
trans->block_group = block_group;
* Check if the given range cross stripes.
* To ensure kernel scrub won't causing bug on with METADATA in mixed
* block group
+ *
+ * Return 1 if the range crosses STRIPE boundary
+ * Return 0 if the range doesn't cross STRIPE boundary or it
+ * doesn't belong to any block group (no boundary to cross)
*/
-static inline int check_crossing_stripes(u64 start, u64 len)
+static inline int check_crossing_stripes(struct btrfs_fs_info *fs_info,
+ u64 start, u64 len)
{
- return (start / BTRFS_STRIPE_LEN) !=
- ((start + len - 1) / BTRFS_STRIPE_LEN);
+ struct btrfs_block_group_cache *bg_cache;
+ u64 bg_offset;
+
+ bg_cache = btrfs_lookup_block_group(fs_info, start);
+ /*
+ * Does not belong to block group, no boundary to cross
+ * although it's a bigger problem, but here we don't care.
+ */
+ if (!bg_cache)
+ return 0;
+ bg_offset = start - bg_cache->key.objectid;
+
+ return (bg_offset / BTRFS_STRIPE_LEN !=
+ (bg_offset + len - 1) / BTRFS_STRIPE_LEN);
}
int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,