Btrfs Sends In Fixes For Linux 6.10 & Restores "norecovery" Mount Option

Last week saw the main Btrfs pull request for Linux 6.10 that delivered on some performance optimizations while today saw a secondary set of merge window changes for this CoW file-system that is now adding back the "norecovery" mount option.

Btrfs' "norecovery" mount option had been deprecated for a while before being dropped in Linux 6.8. But... multiple user-space projects relied on the "norecovery" option and hadn't migrated to Btrfs' preferred option of "rescue=nologreplay" instead. This caused problems from systemd to YaST. As such, this "norecovery" option is being added back to avoid user-space breakage and it's just an alias anyhow for the "rescue=nologreplay" option.

The Btrfs "norecovery" option is used to not attempt any data recovery at mount time by disabling log replay and other write operations. While Btrfs' norecovery was deprecated back in Linux 5.11 and only dropped in Linux 6.8, there's user-space software running into errors now trying to use this dropped option when trying to mount a Btrfs file-system without any writes. Other file-systems have also similarly supported the "norecovery" option.

So to avoid this confusion and user-space problems, the "norecovery" option is being added to Linux 6.10 Git and is also marked for back-porting to the Linux 6.8 and 6.9 kernels.

That's all been squared away with today's Btrfs pull request.