f2fs-for-5.17-rc1 In this round, we've tried to address some performance issues in f2fs_checkpoint and direct IO flows. Also, there was a work to enhance the page cache management used for compression. Other than them, we've done typical work including sysfs, code clean-ups, tracepoint, sanity check, in addition to bug fixes on corner cases. Enhancement: - use iomap for direct IO - try to avoid lock contention to improve f2fs_ckpt speed - avoid unnecessary memory allocation in compression flow - POSIX_FADV_DONTNEED drops the page cache containing compression pages - add some sysfs entries (gc_urgent_high_remaining, pending_discard) Bug fix: - try not to expose unwritten blocks to user by DIO : this was added to avoid merge conflict; another patch is coming to address other missing case. - relax minor error condition for file pinning feature used in Android OTA - fix potential deadlock case in compression flow - should not truncate any block on pinned file In addition, we've done some code clean-ups and tracepoint/sanity check improvement.