3.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jan Schmidt <list.btrfs@xxxxxxxxxxxxx>
commit d9abbf1c3131b679379762700201ae69367f3f62 upstream.
To resolve backrefs, ROOT_REPLACE operations in the tree mod log are
required to be tied to at least one KEY_REMOVE_WHILE_FREEING operation.
Therefore, those operations must be enclosed by tree_mod_log_write_lock()
and tree_mod_log_write_unlock() calls.
Those calls are private to the tree_mod_log_* functions, which means that
removal of the elements of an old root node must be logged from
tree_mod_log_insert_root. This partly reverts and corrects commit ba1bfbd5
(Btrfs: fix a tree mod logging issue for root replacement operations).
This fixes the brand-new version of xfstest 276 as of commit cfe73f71.
Signed-off-by: Jan Schmidt <list.btrfs@xxxxxxxxxxxxx>
Signed-off-by: Josef Bacik <jbacik@xxxxxxxxxxxx>
Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/ctree.c | 30 ++++++++++++++++++++----------
1 file changed, 20 insertions(+), 10 deletions(-)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -651,6 +651,8 @@ tree_mod_log_insert_root(struct btrfs_fs
if (tree_mod_dont_log(fs_info, NULL))
return 0;
+ __tree_mod_log_free_eb(fs_info, old_root);
+
ret = tree_mod_alloc(fs_info, flags, &tm);
if (ret < 0)
goto out;
@@ -736,7 +738,7 @@ tree_mod_log_search(struct btrfs_fs_info
static noinline void
tree_mod_log_eb_copy(struct btrfs_fs_info *fs_info, struct extent_buffer *dst,
struct extent_buffer *src, unsigned long dst_offset,
- unsigned long src_offset, int nr_items)
+ unsigned long src_offset, int nr_items, int log_removal)
{
int ret;
int i;
@@ -750,10 +752,12 @@ tree_mod_log_eb_copy(struct btrfs_fs_inf
}
for (i = 0; i < nr_items; i++) {
- ret = tree_mod_log_insert_key_locked(fs_info, src,
- i + src_offset,
- MOD_LOG_KEY_REMOVE);
- BUG_ON(ret < 0);
+ if (log_removal) {
+ ret = tree_mod_log_insert_key_locked(fs_info, src,
+ i + src_offset,
+ MOD_LOG_KEY_REMOVE);
+ BUG_ON(ret < 0);
+ }
ret = tree_mod_log_insert_key_locked(fs_info, dst,
i + dst_offset,
MOD_LOG_KEY_ADD);
@@ -927,7 +931,6 @@ static noinline int update_ref_for_cow(s
ret = btrfs_dec_ref(trans, root, buf, 1, 1);
BUG_ON(ret); /* -ENOMEM */
}
- tree_mod_log_free_eb(root->fs_info, buf);
clean_tree_block(trans, root, buf);
*last_ref = 1;
}
@@ -1046,6 +1049,7 @@ static noinline int __btrfs_cow_block(st
btrfs_set_node_ptr_generation(parent, parent_slot,
trans->transid);
btrfs_mark_buffer_dirty(parent);
+ tree_mod_log_free_eb(root->fs_info, buf);
btrfs_free_tree_block(trans, root, buf, parent_start,
last_ref);
}
@@ -1755,7 +1759,6 @@ static noinline int balance_level(struct
goto enospc;
}
- tree_mod_log_free_eb(root->fs_info, root->node);
tree_mod_log_set_root_pointer(root, child);
rcu_assign_pointer(root->node, child);
@@ -3000,7 +3003,7 @@ static int push_node_left(struct btrfs_t
push_items = min(src_nritems - 8, push_items);
tree_mod_log_eb_copy(root->fs_info, dst, src, dst_nritems, 0,
- push_items);
+ push_items, 1);
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(dst_nritems),
btrfs_node_key_ptr_offset(0),
@@ -3071,7 +3074,7 @@ static int balance_node_right(struct btr
sizeof(struct btrfs_key_ptr));
tree_mod_log_eb_copy(root->fs_info, dst, src, 0,
- src_nritems - push_items, push_items);
+ src_nritems - push_items, push_items, 1);
copy_extent_buffer(dst, src,
btrfs_node_key_ptr_offset(0),
btrfs_node_key_ptr_offset(src_nritems - push_items),
@@ -3223,12 +3226,18 @@ static noinline int split_node(struct bt
int mid;
int ret;
u32 c_nritems;
+ int tree_mod_log_removal = 1;
c = path->nodes[level];
WARN_ON(btrfs_header_generation(c) != trans->transid);
if (c == root->node) {
/* trying to split the root, lets make a new one */
ret = insert_new_root(trans, root, path, level + 1);
+ /*
+ * removal of root nodes has been logged by
+ * tree_mod_log_set_root_pointer due to locking
+ */
+ tree_mod_log_removal = 0;
if (ret)
return ret;
} else {
@@ -3266,7 +3275,8 @@ static noinline int split_node(struct bt
(unsigned long)btrfs_header_chunk_tree_uuid(split),
BTRFS_UUID_SIZE);
- tree_mod_log_eb_copy(root->fs_info, split, c, 0, mid, c_nritems - mid);
+ tree_mod_log_eb_copy(root->fs_info, split, c, 0, mid, c_nritems - mid,
+ tree_mod_log_removal);
copy_extent_buffer(split, c,
btrfs_node_key_ptr_offset(0),
btrfs_node_key_ptr_offset(mid),
--
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