Define a global enum extents_operation to record extents are pinned, excluded or new chunk is allocated for extents. Although global variable is not so graceful, it simplifies codes much.
New function try_avoid_extents_overwrite() will try to mark block groups full and allocate a new chunk. If it failed because of no space or wrong used bytes(fsck-tests/004), then try to exclude metadata blocks. Signed-off-by: Su Yue <[email protected]> --- cmds-check.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) diff --git a/cmds-check.c b/cmds-check.c index 311c8a9f45e8..9042bab93785 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -84,6 +84,15 @@ enum btrfs_check_mode { static enum btrfs_check_mode check_mode = CHECK_MODE_DEFAULT; +enum lowmem_extents_operation { + EXTENTS_PIN, + EXTENTS_EXCLUDE, + EXTENTS_MARK_BG_FULL, + EXTENTS_NONE +}; + +static enum lowmem_extents_operation extents_operation = EXTENTS_NONE; + struct extent_backref { struct rb_node node; unsigned int is_data:1; @@ -13517,6 +13526,98 @@ out: return err; } +static void cleanup_excluded_extents(struct btrfs_fs_info *fs_info); +static int end_avoid_extents_overwrite(struct btrfs_fs_info *fs_info) +{ + int ret; + + switch (extents_operation) { + case EXTENTS_PIN: + ret = btrfs_finish_extent_commit(NULL, fs_info->extent_root, + &fs_info->pinned_extents); + break; + case EXTENTS_EXCLUDE: + cleanup_excluded_extents(fs_info); + ret = 0; + break; + case EXTENTS_MARK_BG_FULL: + ret = modify_block_groups_cache(fs_info, + BTRFS_BLOCK_GROUP_METADATA, 0); + break; + case EXTENTS_NONE: + ret = 0; + break; + default: + ret = -EINVAL; + } + + if (!ret) + extents_operation = EXTENTS_NONE; + return ret; +} + +static int pin_metadata_blocks(struct btrfs_fs_info *fs_info); +static int exclude_metadata_blocks(struct btrfs_fs_info *fs_info); +/* + * NOTE: Do not call this function during transaction. + */ +static int avoid_extents_overwrite(struct btrfs_fs_info *fs_info, + enum lowmem_extents_operation op) +{ + int ret; + + if (op == extents_operation) + return 0; + + switch (op) { + case EXTENTS_PIN: + ret = pin_metadata_blocks(fs_info); + break; + case EXTENTS_EXCLUDE: + ret = exclude_metadata_blocks(fs_info); + break; + case EXTENTS_MARK_BG_FULL: + ret = force_cow_in_new_chunk(fs_info); + break; + case EXTENTS_NONE: + ret = 0; + break; + default: + return -EINVAL; + } + + /* extents_operation should be assigned anyway for latter clean up. */ + extents_operation = op; + + if (ret) + end_avoid_extents_overwrite(fs_info); + return ret; +} + +static int try_avoid_extents_overwrite(struct btrfs_fs_info *fs_info) +{ + int ret; + int mixed = btrfs_fs_incompat(fs_info, MIXED_GROUPS); + + if (extents_operation != EXTENTS_NONE) + return 0; + ret = avoid_extents_overwrite(fs_info, EXTENTS_MARK_BG_FULL); + + /* + * If there is no space left to allocate, try to exclude all metadata + * blocks. Mix filesystem is unsupported. + */ + if (ret && ret == -ENOSPC && !mixed) { + printf( + "Try to exclude all metadata blcoks and extents, it may be slow\n"); + ret = avoid_extents_overwrite(fs_info, EXTENTS_EXCLUDE); + } + + if (ret) + error("failed to avoid extents overwrite %s", strerror(-ret)); + return ret; +} + /* * Low memory usage version check_chunks_and_extents. */ -- 2.15.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
