$ the-wire · showcase
VFS pulls land with iterator model and kthread isolation
By RepoJournal · Filed · About Linux · Composed from the cited sources · methodology
3 people shipped this
The VFS layer just shipped its most consequential refactor in years, and it changes how the kernel handles filesystem access for every thread on your box.
The VFS merge window delivered five pulls from Christian Brauner that together reshape core filesystem behavior. The biggest is the conversion of iomap to a single ->iomap_next() callback, finishing the move to an iterator model and eliminating indirect calls on every iteration step [1]. Just as significant, kernel threads no longer share filesystem state with userspace, a 3-cycle effort that ends the need for pivot_root() to rewrite the fs_struct of all kthreads [2]. The overlayfs pull lets the merged mount itself be idmapped via mount_setattr(MOUNT_ATTR_IDMAP), so the same tree can expose different ownership views [3]. Lookup gets a refactor too, with mnt_want_write() and parent locking moved into lookup_open() and vfs_lookup_open() added for nfsd [4]. The misc pull tidies lockref dead-count handling and makes put_mnt_ns() leave mounts connected, fixing a subtle issue with open file descriptors in a destroyed namespace [5]. Over on the Omarchy desk, passwordless OWE Wi-Fi networks now connect without a passphrase prompt or lock icon, and all 180 test files pass [6]. Clipboard history gets UTF-16 decoding with BOM detection and ambiguity fallback [7]. The mise-bin switch brings PGO+BOLT-optimized builds but requires a migration because the packages conflict [8]. This is a headline merge window for the VFS, and the iomap iterator is the upgrade you will feel in every filesystem driver.
Action items
- → Review the iomap iterator change for any out-of-tree filesystem drivers torvalds/linux [plan]
- → Test pivot_root behavior with the new kthread fs isolation torvalds/linux [plan]
- → Apply the mise-bin migration on existing Omarchy installs basecamp/omarchy [immediate]
- → Verify OWE network handling with the updated Wi-Fi code basecamp/omarchy [monitor]
References
- [1] Merge tag 'vfs-7.3-rc1.iomap' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs torvalds/linux ↗
- [2] Merge tag 'vfs-7.3-rc1.kthread' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs torvalds/linux ↗
- [3] Merge tag 'vfs-7.3-rc1.ovl' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs torvalds/linux ↗
- [4] Merge tag 'vfs-7.3-rc1.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs torvalds/linux ↗
- [5] Merge tag 'vfs-7.3-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs torvalds/linux ↗
- [6] Fix passwordless OWE Wi-Fi handling ↗ basecamp/omarchy
- [7] Decode UTF-16 text in clipboard history ↗ basecamp/omarchy
- [8] Switch to the mise-bin package (#7244) ↗ basecamp/omarchy
