scoutfs mkfs had two block writing functions: write_block to fill out
some block header fields including crc calculation, and then
write_block_raw to pwrite the raw buffer to the bytes in the device.
These were used inconsistenly as blocks came and went over time. Most
callers filled out all the header fields themselves and called the raw
writer. write_block was only used for super writing, which made sense
because it clobbered the block's header with the super header so the
caller's set header magic and seq fields would be lost.
This cleans up the mess. We only have one block writer and the caller
provides all the hdr fields. Everything uses it instead of filling out
the fields themselves and calling the raw writer.
Signed-off-by: Zach Brown <zab@versity.com>
Use little helpers to insert items into new single block btrees for
mkfs. We're about to insert a whole bunch more items.
Signed-off-by: Zach Brown <zab@versity.com>
