The first patch adjusts the default allowable holes for checkpointing, and the next two patches fix underflow issues related to inc_valid_block_count and inc_valid_node_count. The final one adds a new feature for checkpointing where the user can specify an acceptable amount of space to lose access to up front in checkpointing=disable mode instead of requiring garbage collection. There is still a question around what to do when the current reserved space is less than reserved. As it stands, when a block is deleted, if it was an old block, the space is not actually given back, and is marked as unusable. But current reserve may still rise towards reserve, which would make freeing one block result in a net loss of one block, as opposed to no change. Reserved and unusable serve the same function, so it may make sense to just handle it as max(current_reserved, unusable), which effectively removes the double counting. I'm leaving that until later. Changes from v2: Adjust threshold for initial unusable blocks Patches to fix underflows Added option to set a block limit in addition to a percent for initial unusable space Daniel Rosenberg (4): f2fs: Lower threshold for disable_cp_again f2fs: Fix root reserved on remount f2fs: Fix accounting for unusable blocks f2fs: Add option to limit required GC for checkpoint=disable Documentation/ABI/testing/sysfs-fs-f2fs | 8 ++++ Documentation/filesystems/f2fs.txt | 19 +++++++- fs/f2fs/f2fs.h | 22 ++++++--- fs/f2fs/segment.c | 21 +++++++-- fs/f2fs/super.c | 62 ++++++++++++++++--------- fs/f2fs/sysfs.c | 16 +++++++ 6 files changed, 115 insertions(+), 33 deletions(-) -- 2.22.0.rc1.257.g3120a18244-goog
