Re: [f2fs-dev] [PATCH] generic/064: allow 50 extents on F2FS after fcollapse

On Tue, Jun 30, 2026 at 08:09:19PM +0800, Chao Yu wrote:
> 
> Let me explain it briefly, this is because f2fs has only one copy of reverse
> mapping table (aka SSA), for any checkpointed data, we can not modify SSA info
> directly during remap, otherwise, after sudden power-cut, we will suffer
> inconsistent issue in between reverse mapping table and mapping table. So, f2fs
> choose to rewrite for any checkpointed data.

So looking at this explanation and the code, f2fs does not actually
support COLLAPSE_RANGE at all, but emulates by doing a full data
copy.  What is the point of this and lying to the user that it supports
and operation that isn't actually supported as the intended metadata
only swizzle?