f2fs: cache: support asynchronous write_end_io

Currently, f2fs_cache_write_end_io() synchronously traverses all
cached blocks in the write bio to perform node footer sanity checks,
warm node cleanup, and writeback completion. If called from atomic
context (e.g. interrupt context) with a large batch of metadata
blocks, this traversal can induce significant IRQ latency.

Furthermore, f2fs_write_end_io() already implements asynchronous
offloading via workqueue when in atomic context and exceeding the
max_atc_write_bio_size threshold.

To avoid code duplication and mitigate atomic context latency for
metadata cache writes:
1. Unify the write completion handler by pointing all write bios to
   f2fs_write_end_io() with bio->bi_private = sbi.
2. In f2fs_write_end_bio(), check f2fs_is_cache_bio(bio) to dispatch
   to f2fs_cache_write_end_bio().
3. Simplify f2fs_zone_write_end_io() to call f2fs_write_end_io() directly.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

0 files changed, 0 insertions, 0 deletions