[$] Removing GFP_NOFS

The GFP_NOFS flag is meant for kernel memory allocations that
should not cause a call into the filesystems to reclaim memory because there are
already locks held that can potentially cause a deadlock. The 'scoped
allocation' API is a better choice for filesystems to indicate that they
are holding a lock, so GFP_NOFS has long been on the chopping block, though
progress has been slow. In a filesystem-track session at
the 2024 Linux Storage,
Filesystem, Memory Management, and BPF Summit, Matthew Wilcox wanted to
discuss how to move kernel filesystems away from the flag with the eventual
goal of removing it completely.