diff options
author | Qu Wenruo <quwenruo@cn.fujitsu.com> | 2015-04-16 09:54:50 +0300 |
---|---|---|
committer | Chris Mason <clm@fb.com> | 2015-06-10 19:25:45 +0300 |
commit | 21633fc6037f8ceb2bb927dacc3f9ef46ccae891 (patch) | |
tree | d031ae663b36cba46e061d03c8161e2418442b74 | |
parent | 3b7d00f99c60b31e1cff0efc6b9178eea3696e27 (diff) | |
download | linux-21633fc6037f8ceb2bb927dacc3f9ef46ccae891.tar.xz |
btrfs: backref: Add special time_seq == (u64)-1 case for
btrfs_find_all_roots().
Allow btrfs_find_all_roots() to skip all delayed_ref_head lock and tree
lock to do tree search.
This is important for later qgroup implement which will call
find_all_roots() after fs trees are committed.
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
-rw-r--r-- | fs/btrfs/backref.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 49bc5a41c1f8..802fabb30e15 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -250,8 +250,12 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, * the first item to check. But sometimes, we may enter it with * slot==nritems. In that case, go to the next leaf before we continue. */ - if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) - ret = btrfs_next_old_leaf(root, path, time_seq); + if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) { + if (time_seq == (u64)-1) + ret = btrfs_next_leaf(root, path); + else + ret = btrfs_next_old_leaf(root, path, time_seq); + } while (!ret && count < total_refs) { eb = path->nodes[0]; @@ -291,7 +295,10 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path, eie = NULL; } next: - ret = btrfs_next_old_item(root, path, time_seq); + if (time_seq == (u64)-1) + ret = btrfs_next_item(root, path); + else + ret = btrfs_next_old_item(root, path, time_seq); } if (ret > 0) @@ -334,6 +341,8 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, if (path->search_commit_root) root_level = btrfs_header_level(root->commit_root); + else if (time_seq == (u64)-1) + root_level = btrfs_header_level(root->node); else root_level = btrfs_old_root_level(root, time_seq); @@ -343,7 +352,12 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, } path->lowest_level = level; - ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq); + if (time_seq == (u64)-1) + ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, + 0, 0); + else + ret = btrfs_search_old_slot(root, &ref->key_for_search, path, + time_seq); /* root node has been locked, we can release @subvol_srcu safely here */ srcu_read_unlock(&fs_info->subvol_srcu, index); @@ -879,6 +893,11 @@ static int __add_keyed_refs(struct btrfs_fs_info *fs_info, * * NOTE: This can return values > 0 * + * If time_seq is set to (u64)-1, it will not search delayed_refs, and behave + * much like trans == NULL case, the difference only lies in it will not + * commit root. + * The special case is for qgroup to search roots in commit_transaction(). + * * FIXME some caching might speed things up */ static int find_parent_nodes(struct btrfs_trans_handle *trans, @@ -917,6 +936,9 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans, path->skip_locking = 1; } + if (time_seq == (u64)-1) + path->skip_locking = 1; + /* * grab both a lock on the path and a lock on the delayed ref head. * We need both to get a consistent picture of how the refs look @@ -931,9 +953,10 @@ again: BUG_ON(ret == 0); #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS - if (trans && likely(trans->type != __TRANS_DUMMY)) { + if (trans && likely(trans->type != __TRANS_DUMMY) && + time_seq != (u64)-1) { #else - if (trans) { + if (trans && time_seq != (u64)-1) { #endif /* * look if there are updates for this ref queued and lock the |