f2fs: compress: fix to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock
In the Linux kernel, the following vulnerability has been resolved:

f2fs: compress: fix to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock

It needs to cover {reserve,release}_compress_blocks() w/ cp_rwsem lock
to avoid racing with checkpoint, otherwise, filesystem metadata including
blkaddr in dnode, inode fields and .total_valid_block_count may be
corrupted after SPO case.