On 2018/9/5 下午1:42, Nikolay Borisov wrote:
>
>
> On 5.09.2018 05:10, Qu Wenruo wrote:
>>
>>
>> On 2018/8/16 下午9:10, Nikolay Borisov wrote:
>>> This commit enables the delayed refs infrastructures. This entails doing
>>> the following:
>>>
>>> 1. Replacing existing calls of btrfs_extent_post_op (which is the
>>> equivalent of delayed refs) with the proper btrfs_run_delayed_refs.
>>> As well as eliminating open-coded calls to finish_current_insert and
>>> del_pending_extents which execute the delayed ops.
>>>
>>> 2. Wiring up the addition of delayed refs when freeing extents
>>> (btrfs_free_extent) and when adding new extents (alloc_tree_block).
>>>
>>> 3. Adding calls to btrfs_run_delayed refs in the transaction commit
>>> path alongside comments why every call is needed, since it's not always
>>> obvious (those call sites were derived empirically by running and
>>> debugging existing tests)
>>>
>>> 4. Correctly flagging the transaction in which we are reinitialising
>>> the extent tree.
>>>
>>> 5 Moving btrfs_write_dirty_block_groups to btrfs_write_dirty_block_groups
>>> since blockgroups should be written to disk after the last delayed refs
>>> have been run.
>>>
>>> Signed-off-by: Nikolay Borisov <nbori...@suse.com>
>>> Signed-off-by: David Sterba <dste...@suse.com>
>>
>> Is there something (maybe btrfs_run_delayed_refs()?) missing in btrfs-image?
>>
>> btrfs-image from devel branch can't restore image correctly, the block
>> group used bytes is not correct, thus it can't pass misc nor fsck tests.
>
> This is really strange, all fsck/misc tests passed with those patches.
> Can you be more specific which tests exactly you mean ?
One case is fsck/020 with lowmem mode. (Original mode lacks block
group->used check).
More specifically, fsck/020/keyed_data_ref_with_shared_leaf.img
Using btrfs-image from my distribution (v4.17.1) and devel branch btrfs
check: (cwd is btrfs-progs, devel branch)
$ btrfs-image -r
tests/fsck-tests/020-extent-ref-cases/keyed_data_ref_with_shared_leaf.img
~/test.img
$ btrfs check --mode=lowmem ~/test.img
Opening filesystem to check...
Checking filesystem on /home/adam/test.img
UUID: 12dabcf2-d4da-4a70-9701-9f3d48074e73
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
[4/7] checking fs roots
[5/7] checking only csums items (without verifying data)
[6/7] checking root refs done with fs roots in lowmem mode, skipping
[7/7] checking quota groups skipped (not enabled on this FS)
found 1208320 bytes used, no error found
total csum bytes: 512
total tree bytes: 684032
total fs tree bytes: 638976
total extent tree bytes: 16384
btree space waste bytes: 305606
file data blocks allocated: 93847552
referenced 1773568
But if using btrfs-image with your delayed ref patch:
$ ./btrfs-image -r
tests/fsck-tests/020-extent-ref-cases/keyed_data_ref_with_shared_leaf.img
~/test.img
# No matter if I'm using btrfs-check from devel or 4.17.1
$ btrfs check --mode=lowmem ~/test.img
Opening filesystem to check...
Checking filesystem on /home/adam/test.img
UUID: 12dabcf2-d4da-4a70-9701-9f3d48074e73
[1/7] checking root items
[2/7] checking extents
ERROR: block group[4194304 8388608] used 20480 but extent items used 24576
ERROR: block group[20971520 16777216] used 659456 but extent items used
655360
ERROR: errors found in extent allocation tree or chunk allocation
[3/7] checking free space cache
[4/7] checking fs roots
[5/7] checking only csums items (without verifying data)
[6/7] checking root refs done with fs roots in lowmem mode, skipping
[7/7] checking quota groups skipped (not enabled on this FS)
found 1208320 bytes used, error(s) found
total csum bytes: 512
total tree bytes: 684032
total fs tree bytes: 638976
total extent tree bytes: 16384
btree space waste bytes: 305606
file data blocks allocated: 93847552
referenced 1773568
I'd say, although lowmem check is still far from perfect, it indeed has
extra checks original mode lacks, and in this case it indeed exposes
problem.
Thanks,
Qu
>
>>
>> Thanks,
>> Qu
>>
>>> ---
>>> check/main.c | 3 +-
>>> extent-tree.c | 166
>>> ++++++++++++++++++++++++++++++----------------------------
>>> transaction.c | 27 +++++++++-
>>> 3 files changed, 112 insertions(+), 84 deletions(-)
>>>
>>> diff --git a/check/main.c b/check/main.c
>>> index bc2ee22f7943..b361cd7e26a0 100644
>>> --- a/check/main.c
>>> +++ b/check/main.c
>>> @@ -8710,7 +8710,7 @@ static int reinit_extent_tree(struct
>>> btrfs_trans_handle *trans,
>>> fprintf(stderr, "Error adding block group\n");
>>> return ret;
>>> }
>>> - btrfs_extent_post_op(trans);
>>> + btrfs_run_delayed_refs(trans, -1);
>>> }
>>>
>>> ret = reset_balance(trans, fs_info);
>>> @@ -9767,6 +9767,7 @@ int cmd_check(int argc, char **argv)
>>> goto close_out;
>>> }
>>>
>>> + trans->reinit_extent_tree = true;
>>> if (init_extent_tree) {
>>> printf("Creating a new extent tree\n");
>>> ret = reinit_extent_tree(trans, info,
>>> diff --git a/extent-tree.c b/extent-tree.c
>>> index 7d6c37c6b371..2fa51bbc0359 100644
>>> --- a/extent-tree.c
>>> +++ b/extent-tree.c
>>> @@ -1418,8 +1418,6 @@ int btrfs_inc_extent_ref(struct btrfs_trans_handle
>>> *trans,
>>> err = ret;
>>> out:
>>> btrfs_free_path(path);
>>> - finish_current_insert(trans);
>>> - del_pending_extents(trans);
>>> BUG_ON(err);
>>> return err;
>>> }
>>> @@ -1602,8 +1600,6 @@ int btrfs_set_block_flags(struct btrfs_trans_handle
>>> *trans, u64 bytenr,
>>> btrfs_set_extent_flags(l, item, flags);
>>> out:
>>> btrfs_free_path(path);
>>> - finish_current_insert(trans);
>>> - del_pending_extents(trans);
>>> return ret;
>>> }
>>>
>>> @@ -1701,7 +1697,6 @@ static int write_one_cache_group(struct
>>> btrfs_trans_handle *trans,
>>> struct btrfs_block_group_cache *cache)
>>> {
>>> int ret;
>>> - int pending_ret;
>>> struct btrfs_root *extent_root = trans->fs_info->extent_root;
>>> unsigned long bi;
>>> struct extent_buffer *leaf;
>>> @@ -1717,12 +1712,8 @@ static int write_one_cache_group(struct
>>> btrfs_trans_handle *trans,
>>> btrfs_mark_buffer_dirty(leaf);
>>> btrfs_release_path(path);
>>> fail:
>>> - finish_current_insert(trans);
>>> - pending_ret = del_pending_extents(trans);
>>> if (ret)
>>> return ret;
>>> - if (pending_ret)
>>> - return pending_ret;
>>> return 0;
>>>
>>> }
>>> @@ -2049,6 +2040,7 @@ static int finish_current_insert(struct
>>> btrfs_trans_handle *trans)
>>> int skinny_metadata =
>>> btrfs_fs_incompat(extent_root->fs_info, SKINNY_METADATA);
>>>
>>> +
>>> while(1) {
>>> ret = find_first_extent_bit(&info->extent_ins, 0, &start,
>>> &end, EXTENT_LOCKED);
>>> @@ -2080,6 +2072,8 @@ static int finish_current_insert(struct
>>> btrfs_trans_handle *trans)
>>> BUG_ON(1);
>>> }
>>>
>>> +
>>> + printf("shouldn't be executed\n");
>>> clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED);
>>> kfree(extent_op);
>>> }
>>> @@ -2379,7 +2373,6 @@ static int __free_extent(struct btrfs_trans_handle
>>> *trans,
>>> }
>>> fail:
>>> btrfs_free_path(path);
>>> - finish_current_insert(trans);
>>> return ret;
>>> }
>>>
>>> @@ -2462,33 +2455,30 @@ int btrfs_free_extent(struct btrfs_trans_handle
>>> *trans,
>>> u64 bytenr, u64 num_bytes, u64 parent,
>>> u64 root_objectid, u64 owner, u64 offset)
>>> {
>>> - struct btrfs_root *extent_root = root->fs_info->extent_root;
>>> - int pending_ret;
>>> int ret;
>>>
>>> WARN_ON(num_bytes < root->fs_info->sectorsize);
>>> - if (root == extent_root) {
>>> - struct pending_extent_op *extent_op;
>>> -
>>> - extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
>>> - BUG_ON(!extent_op);
>>> -
>>> - extent_op->type = PENDING_EXTENT_DELETE;
>>> - extent_op->bytenr = bytenr;
>>> - extent_op->num_bytes = num_bytes;
>>> - extent_op->level = (int)owner;
>>> -
>>> - set_extent_bits(&root->fs_info->pending_del,
>>> - bytenr, bytenr + num_bytes - 1,
>>> - EXTENT_LOCKED);
>>> - set_state_private(&root->fs_info->pending_del,
>>> - bytenr, (unsigned long)extent_op);
>>> - return 0;
>>> + /*
>>> + * tree log blocks never actually go into the extent allocation
>>> + * tree, just update pinning info and exit early.
>>> + */
>>> + if (root_objectid == BTRFS_TREE_LOG_OBJECTID) {
>>> + printf("PINNING EXTENTS IN LOG TREE\n");
>>> + WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID);
>>> + btrfs_pin_extent(trans->fs_info, bytenr, num_bytes);
>>> + ret = 0;
>>> + } else if (owner < BTRFS_FIRST_FREE_OBJECTID) {
>>> + BUG_ON(offset);
>>> + ret = btrfs_add_delayed_tree_ref(trans->fs_info, trans,
>>> + bytenr, num_bytes, parent,
>>> + root_objectid, (int)owner,
>>> + BTRFS_DROP_DELAYED_REF,
>>> + NULL, NULL, NULL);
>>> + } else {
>>> + ret = __free_extent(trans, bytenr, num_bytes, parent,
>>> + root_objectid, owner, offset, 1);
>>> }
>>> - ret = __free_extent(trans, bytenr, num_bytes, parent,
>>> - root_objectid, owner, offset, 1);
>>> - pending_ret = del_pending_extents(trans);
>>> - return ret ? ret : pending_ret;
>>> + return ret;
>>> }
>>>
>>> static u64 stripe_align(struct btrfs_root *root, u64 val)
>>> @@ -2694,6 +2684,8 @@ static int alloc_reserved_tree_block2(struct
>>> btrfs_trans_handle *trans,
>>> struct btrfs_delayed_tree_ref *ref =
>>> btrfs_delayed_node_to_tree_ref(node);
>>> struct btrfs_key ins;
>>> bool skinny_metadata = btrfs_fs_incompat(trans->fs_info,
>>> SKINNY_METADATA);
>>> + int ret;
>>> + u64 start, end;
>>>
>>> ins.objectid = node->bytenr;
>>> if (skinny_metadata) {
>>> @@ -2704,10 +2696,25 @@ static int alloc_reserved_tree_block2(struct
>>> btrfs_trans_handle *trans,
>>> ins.type = BTRFS_EXTENT_ITEM_KEY;
>>> }
>>>
>>> - return alloc_reserved_tree_block(trans, ref->root, trans->transid,
>>> - extent_op->flags_to_set,
>>> - &extent_op->key, ref->level, &ins);
>>> + if (ref->root == BTRFS_EXTENT_TREE_OBJECTID) {
>>> + ret = find_first_extent_bit(&trans->fs_info->extent_ins,
>>> + node->bytenr, &start, &end,
>>> + EXTENT_LOCKED);
>>> + ASSERT(!ret);
>>> + ASSERT(start == node->bytenr);
>>> + ASSERT(end == node->bytenr + node->num_bytes - 1);
>>> + }
>>> +
>>> + ret = alloc_reserved_tree_block(trans, ref->root, trans->transid,
>>> + extent_op->flags_to_set,
>>> + &extent_op->key, ref->level, &ins);
>>>
>>> + if (ref->root == BTRFS_EXTENT_TREE_OBJECTID) {
>>> + clear_extent_bits(&trans->fs_info->extent_ins, start, end,
>>> + EXTENT_LOCKED);
>>> + }
>>> +
>>> + return ret;
>>> }
>>>
>>> static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans,
>>> @@ -2772,39 +2779,50 @@ static int alloc_tree_block(struct
>>> btrfs_trans_handle *trans,
>>> u64 search_end, struct btrfs_key *ins)
>>> {
>>> int ret;
>>> + u64 extent_size;
>>> + struct btrfs_delayed_extent_op *extent_op;
>>> + bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
>>> + SKINNY_METADATA);
>>> +
>>> + extent_op = btrfs_alloc_delayed_extent_op();
>>> + if (!extent_op)
>>> + return -ENOMEM;
>>> +
>>> ret = btrfs_reserve_extent(trans, root, num_bytes, empty_size,
>>> hint_byte, search_end, ins, 0);
>>> BUG_ON(ret);
>>>
>>> + if (key)
>>> + memcpy(&extent_op->key, key, sizeof(extent_op->key));
>>> + else
>>> + memset(&extent_op->key, 0, sizeof(extent_op->key));
>>> + extent_op->flags_to_set = flags;
>>> + extent_op->update_key = skinny_metadata ? false : true;
>>> + extent_op->update_flags = true;
>>> + extent_op->is_data = false;
>>> + extent_op->level = level;
>>> +
>>> + extent_size = ins->offset;
>>> +
>>> + if (btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
>>> + ins->offset = level;
>>> + ins->type = BTRFS_METADATA_ITEM_KEY;
>>> + }
>>> +
>>> + /* Ensure this reserved extent is not found by the allocator */
>>> if (root_objectid == BTRFS_EXTENT_TREE_OBJECTID) {
>>> - struct pending_extent_op *extent_op;
>>> -
>>> - extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS);
>>> - BUG_ON(!extent_op);
>>> -
>>> - extent_op->type = PENDING_EXTENT_INSERT;
>>> - extent_op->bytenr = ins->objectid;
>>> - extent_op->num_bytes = ins->offset;
>>> - extent_op->level = level;
>>> - extent_op->flags = flags;
>>> - memcpy(&extent_op->key, key, sizeof(*key));
>>> -
>>> - set_extent_bits(&root->fs_info->extent_ins, ins->objectid,
>>> - ins->objectid + ins->offset - 1,
>>> - EXTENT_LOCKED);
>>> - set_state_private(&root->fs_info->extent_ins,
>>> - ins->objectid, (unsigned long)extent_op);
>>> - } else {
>>> - if (btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) {
>>> - ins->offset = level;
>>> - ins->type = BTRFS_METADATA_ITEM_KEY;
>>> - }
>>> - ret = alloc_reserved_tree_block(trans, root_objectid,
>>> - generation, flags,
>>> - key, level, ins);
>>> - finish_current_insert(trans);
>>> - del_pending_extents(trans);
>>> + ret = set_extent_bits(&trans->fs_info->extent_ins,
>>> + ins->objectid,
>>> + ins->objectid + extent_size - 1,
>>> + EXTENT_LOCKED);
>>> +
>>> + BUG_ON(ret);
>>> }
>>> +
>>> + ret = btrfs_add_delayed_tree_ref(root->fs_info, trans, ins->objectid,
>>> + extent_size, 0, root_objectid,
>>> + level, BTRFS_ADD_DELAYED_EXTENT,
>>> + extent_op, NULL, NULL);
>>> return ret;
>>> }
>>>
>>> @@ -3329,11 +3347,6 @@ int btrfs_make_block_group(struct btrfs_trans_handle
>>> *trans,
>>> sizeof(cache->item));
>>> BUG_ON(ret);
>>>
>>> - ret = finish_current_insert(trans);
>>> - BUG_ON(ret);
>>> - ret = del_pending_extents(trans);
>>> - BUG_ON(ret);
>>> -
>>> return 0;
>>> }
>>>
>>> @@ -3429,10 +3442,6 @@ int btrfs_make_block_groups(struct
>>> btrfs_trans_handle *trans,
>>> sizeof(cache->item));
>>> BUG_ON(ret);
>>>
>>> - finish_current_insert(trans);
>>> - ret = del_pending_extents(trans);
>>> - BUG_ON(ret);
>>> -
>>> cur_start = cache->key.objectid + cache->key.offset;
>>> }
>>> return 0;
>>> @@ -3814,14 +3823,9 @@ int btrfs_fix_block_accounting(struct
>>> btrfs_trans_handle *trans)
>>> struct btrfs_fs_info *fs_info = trans->fs_info;
>>> struct btrfs_root *root = fs_info->extent_root;
>>>
>>> - while(extent_root_pending_ops(fs_info)) {
>>> - ret = finish_current_insert(trans);
>>> - if (ret)
>>> - return ret;
>>> - ret = del_pending_extents(trans);
>>> - if (ret)
>>> - return ret;
>>> - }
>>> + ret = btrfs_run_delayed_refs(trans, -1);
>>> + if (ret)
>>> + return ret;
>>>
>>> while(1) {
>>> cache = btrfs_lookup_first_block_group(fs_info, start);
>>> @@ -4026,7 +4030,7 @@ static int __btrfs_record_file_extent(struct
>>> btrfs_trans_handle *trans,
>>> } else if (ret != -EEXIST) {
>>> goto fail;
>>> }
>>> - btrfs_extent_post_op(trans);
>>> + btrfs_run_delayed_refs(trans, -1);
>>> extent_bytenr = disk_bytenr;
>>> extent_num_bytes = num_bytes;
>>> extent_offset = 0;
>>> diff --git a/transaction.c b/transaction.c
>>> index 96d9891b0d1c..bfda769210ee 100644
>>> --- a/transaction.c
>>> +++ b/transaction.c
>>> @@ -61,7 +61,6 @@ static int update_cowonly_root(struct btrfs_trans_handle
>>> *trans,
>>> u64 old_root_bytenr;
>>> struct btrfs_root *tree_root = root->fs_info->tree_root;
>>>
>>> - btrfs_write_dirty_block_groups(trans);
>>> while(1) {
>>> old_root_bytenr = btrfs_root_bytenr(&root->root_item);
>>> if (old_root_bytenr == root->node->start)
>>> @@ -98,6 +97,17 @@ int commit_tree_roots(struct btrfs_trans_handle *trans,
>>> if (ret)
>>> return ret;
>>>
>>> + /*
>>> + * If the above CoW is the first one to dirty the current tree_root,
>>> + * delayed refs for it won't be run until after this function has
>>> + * finished executing, meaning we won't process the extent tree root,
>>> + * which will have been added to ->dirty_cowonly_roots. So run
>>> + * delayed refs here as well.
>>> + */
>>> + ret = btrfs_run_delayed_refs(trans, -1);
>>> + if (ret)
>>> + return ret;
>>> +
>>> while(!list_empty(&fs_info->dirty_cowonly_roots)) {
>>> next = fs_info->dirty_cowonly_roots.next;
>>> list_del_init(next);
>>> @@ -147,6 +157,12 @@ int btrfs_commit_transaction(struct btrfs_trans_handle
>>> *trans,
>>>
>>> if (trans->fs_info->transaction_aborted)
>>> return -EROFS;
>>> + /*
>>> + * Flush all accumulated delayed refs so that root-tree updates are
>>> + * consistent
>>> + */
>>> + ret = btrfs_run_delayed_refs(trans, -1);
>>> + BUG_ON(ret);
>>>
>>> if (root->commit_root == root->node)
>>> goto commit_tree;
>>> @@ -164,11 +180,18 @@ int btrfs_commit_transaction(struct
>>> btrfs_trans_handle *trans,
>>> ret = btrfs_update_root(trans, root->fs_info->tree_root,
>>> &root->root_key, &root->root_item);
>>> BUG_ON(ret);
>>> +
>>> commit_tree:
>>> ret = commit_tree_roots(trans, fs_info);
>>> BUG_ON(ret);
>>> - ret = __commit_transaction(trans, root);
>>> + /*
>>> + * Ensure that all comitted roots are properly accounted in the
>>> + * extent tree
>>> + */
>>> + ret = btrfs_run_delayed_refs(trans, -1);
>>> BUG_ON(ret);
>>> + btrfs_write_dirty_block_groups(trans);
>>> + __commit_transaction(trans, root);
>>> write_ctree_super(trans);
>>> btrfs_finish_extent_commit(trans, fs_info->extent_root,
>>> &fs_info->pinned_extents);
>>>
>>
