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authorQu Wenruo <quwenruo@cn.fujitsu.com>2016-10-24 15:22:33 +0800
committerDavid Sterba <dsterba@suse.com>2016-10-25 14:31:06 +0200
commitffb1b847bd554e45c00212280847b9f2059a87f3 (patch)
treeac814579158f3a29451ed842850989ca7c000d8e
parentb2fbfc8cdd4ce4bf7d22e55695a4cc7e707c9ef3 (diff)
btrfs-progs: Fix wrong tree block alignment for unalianged block group
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>
-rw-r--r--cmds-check.c10
-rw-r--r--extent-tree.c15
-rw-r--r--volumes.h23
3 files changed, 38 insertions, 10 deletions
diff --git a/cmds-check.c b/cmds-check.c
index 670ccd1f..907d60c5 100644
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -4662,8 +4662,8 @@ static int add_extent_rec_nolookup(struct cache_tree *extent_cache,
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;
}
@@ -4764,7 +4764,8 @@ static int add_extent_rec(struct cache_tree *extent_cache,
*/
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;
@@ -9359,7 +9360,8 @@ static int check_extent_item(struct btrfs_fs_info *fs_info,
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;
diff --git a/extent-tree.c b/extent-tree.c
index f6d0a7c1..3b1577e7 100644
--- a/extent-tree.c
+++ b/extent-tree.c
@@ -2606,11 +2606,20 @@ check_failed:
}
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;
diff --git a/volumes.h b/volumes.h
index d7b7d3cc..ee7d56ab 100644
--- a/volumes.h
+++ b/volumes.h
@@ -155,11 +155,28 @@ struct map_lookup {
* 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,