From a929904cf73b650f49cc60941e6e618240096fcb Mon Sep 17 00:00:00 2001 From: David Sterba Date: Wed, 17 Sep 2025 19:53:56 +0200 Subject: btrfs: add unlikely annotations to branches leading to transaction abort The unlikely() annotation is a static prediction hint that compiler may use to reorder code out of hot path. We use it elsewhere (namely tree-checker.c) for error branches that almost never happen. Transaction abort is one such error, the btrfs_abort_transaction() inlines code to check the state and print a warning, this ought to be out of the hot path. The most common pattern is when transaction abort is called after checking a return value and the control flow leads to a quick return. In other cases it may not be necessary to add unlikely() e.g. when the function returns anyway or the control flow is not changed noticeably. Reviewed-by: Filipe Manana Signed-off-by: David Sterba --- fs/btrfs/relocation.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'fs/btrfs/relocation.c') diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 7027572cb6c1..8dd8de6b9fb8 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -967,7 +967,7 @@ int replace_file_extents(struct btrfs_trans_handle *trans, btrfs_init_data_ref(&ref, key.objectid, key.offset, btrfs_root_id(root), false); ret = btrfs_inc_extent_ref(trans, &ref); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); break; } @@ -981,7 +981,7 @@ int replace_file_extents(struct btrfs_trans_handle *trans, btrfs_init_data_ref(&ref, key.objectid, key.offset, btrfs_root_id(root), false); ret = btrfs_free_extent(trans, &ref); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); break; } @@ -1192,7 +1192,7 @@ again: ref.ref_root = btrfs_root_id(src); btrfs_init_tree_ref(&ref, level - 1, 0, true); ret = btrfs_inc_extent_ref(trans, &ref); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); break; } @@ -1205,7 +1205,7 @@ again: ref.ref_root = btrfs_root_id(dest); btrfs_init_tree_ref(&ref, level - 1, 0, true); ret = btrfs_inc_extent_ref(trans, &ref); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); break; } @@ -1219,7 +1219,7 @@ again: ref.ref_root = btrfs_root_id(src); btrfs_init_tree_ref(&ref, level - 1, 0, true); ret = btrfs_free_extent(trans, &ref); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); break; } @@ -1233,7 +1233,7 @@ again: ref.ref_root = btrfs_root_id(dest); btrfs_init_tree_ref(&ref, level - 1, 0, true); ret = btrfs_free_extent(trans, &ref); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); break; } @@ -1784,7 +1784,7 @@ again: list_add(&reloc_root->root_list, &reloc_roots); btrfs_put_root(root); - if (ret) { + if (unlikely(ret)) { btrfs_abort_transaction(trans, ret); if (!err) err = ret; @@ -2325,7 +2325,7 @@ static int do_relocation(struct btrfs_trans_handle *trans, if (!ret) ret = btrfs_drop_subtree(trans, root, eb, upper->eb); - if (ret) + if (unlikely(ret)) btrfs_abort_transaction(trans, ret); } next: -- cgit v1.2.3