| Message ID | 20220309135051.5738-1-gniebler@suse.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | btrfs: Introduce macro to iterate over slots | expand |
On Wed, Mar 09, 2022 at 02:50:37PM +0100, Gabriel Niebler wrote: > There is a common pattern when searching for a key in btrfs: > > * Call btrfs_search_slot to find the slot for the key > * Enter an endless loop: > * If the found slot is larger than the no. of items in the current leaf, > check the next leaf > * If it's still not found in the next leaf, terminate the loop > * Otherwise do something with the found key > * Increment the current slot and continue > > To reduce code duplication, we can replace this code pattern with an iterator > macro, similar to the existing for_each_X macros found elsewhere in the kernel. > This also makes the code easier to understand for newcomers by putting a name > to the encapsulated functionality. > > This patchset survived a complete fstest run. > > Changes from v3: > * Surround arguments with (…) in iterator macro definition (David) > * Fix btrfs_unlink_all_paths after key/found_key confusion broke btrfs/168 > (Josef) > * Various stylistic improvements (David) Added to misc-next with some fixups, thanks.
There is a common pattern when searching for a key in btrfs: * Call btrfs_search_slot to find the slot for the key * Enter an endless loop: * If the found slot is larger than the no. of items in the current leaf, check the next leaf * If it's still not found in the next leaf, terminate the loop * Otherwise do something with the found key * Increment the current slot and continue To reduce code duplication, we can replace this code pattern with an iterator macro, similar to the existing for_each_X macros found elsewhere in the kernel. This also makes the code easier to understand for newcomers by putting a name to the encapsulated functionality. This patchset survived a complete fstest run. Changes from v3: * Surround arguments with (…) in iterator macro definition (David) * Fix btrfs_unlink_all_paths after key/found_key confusion broke btrfs/168 (Josef) * Various stylistic improvements (David) Changes from v2: * Rename btrfs_valid_slot to btrfs_get_next_valid_item (Nikolay) * Fix comment formatting (David) * Remove redundant parentheses and indentation in loop condition (David) * Remove redundant iter_ret var and reuse ret instead (Nikolay) * Make termination condition more consistent in btrfs_unlink_all_paths (Nikolay) * Improved patch organisation by splitting into one patch per function (David) * Improve doc comment for btrfs_get_next_valid_item (Gabriel) * Remove `out` label and assoc. gotos from id_create_dir (Gabriel) * Initialise `ret` in process_all_refs and process_all_new_xattrs (Gabriel) * Remove unneeded btrfs_item_key_to_cpu call from loop body in btrfs_read_chunk_tree (Gabriel) Changes from v1: * Separate xattr changes from the macro introducing code (Johannes) Changes from RFC: * Add documentation to btrfs_for_each_slot macro and btrfs_valid_slot function (David) * Add documentation about the ret variable used as a macro argument (David) * Match function argument from prototype and implementation (David) * Changed ({ }) block to only () in btrfs_for_each_slot macro (David) * Add more patches to show the code being reduced by using this approach (Nikolay) Marcos Paulo de Souza (14): btrfs: Introduce btrfs_for_each_slot iterator macro btrfs: Use btrfs_for_each_slot in find_first_block_group btrfs: Use btrfs_for_each_slot in mark_block_group_to_copy btrfs: Use btrfs_for_each_slot in btrfs_search_dir_index_item btrfs: Use btrfs_for_each_slot in btrfs_real_readdir btrfs: Use btrfs_for_each_slot in did_create_dir btrfs: Use btrfs_for_each_slot in can_rmdir btrfs: Use btrfs_for_each_slot in is_ancestor btrfs: Use btrfs_for_each_slot in process_all_refs btrfs: Use btrfs_for_each_slot in process_all_new_xattrs btrfs: Use btrfs_for_each_slot in process_all_extents btrfs: Use btrfs_for_each_slot in btrfs_unlink_all_paths btrfs: Use btrfs_for_each_slot in btrfs_read_chunk_tree btrfs: Use btrfs_for_each_slot in btrfs_listxattr fs/btrfs/block-group.c | 26 +----- fs/btrfs/ctree.c | 35 ++++++++ fs/btrfs/ctree.h | 25 ++++++ fs/btrfs/dev-replace.c | 40 ++------- fs/btrfs/dir-item.c | 31 ++----- fs/btrfs/inode.c | 35 +++----- fs/btrfs/send.c | 229 +++++++++++++------------------------------------ fs/btrfs/volumes.c | 25 ++---- fs/btrfs/xattr.c | 40 +++------ 9 files changed, 167 insertions(+), 319 deletions(-)