F2FS Adds Opt-In Multi-Grain Timestamps With Linux 7.4, Other Improvements

The F2FS (Flash Friendly File-System) improvements have been merged for Linux 7.4 to further enhance this flash-optimized solution. F2FS in Linux 6.4 brings a dedicated metadata cache that will help toward allowing page sizes to diff from block sizes, similar to the work happening in other Linux file-systems too. Plus opening the door for larger folios too in the future. F2FS also now offers opt-in support for multi-grain timestamps. Multigrain timestamps allow for mixing coarse and fine-grained timestamps for use-cases like enhancing NFS cache coherency without hurting the performance. EXT4, Btrfs, XFS, and others already support multigrain timestamps. Plus there are various F2FS bug fixes and other refinements with this code merged for Linux 7.4. "In this round, key enhancements focus on introducing a dedicated metadata cache infrastructure and dynamically parameterizing on-disk block layouts and geometry macros. Moving meta, node, and compress blocks out of the VFS page cache removes the page == block size assumption for metadata, which along with dynamic block layout descriptions paves the way for large folio and page != block support in the future. We also opt in to multigrain timestamps, add bio entry-count throttling for asynchronous write_end_io completion, and expose the resizable_tail feature via sysfs. Alongside these features, critical bug fixes resolve race conditions across compression, mmap write faults, checkpoint/shutdown, and filesystem freeze, prevent write bio splitting and GC holes on sequential zoned devices, and strengthen on-disk sanity checks for SIT/NAT bitmaps, read-only curseg entries, and device aliasing. Additional stability patches address online resize, roll-forward recovery, atomic file operations, quota handling, and dirty inode syncing livelocks." All in a nice round of incremental improvements with the F2FS updates for Linux 7.4.