mergerfs v2.42.0

Donations / Sponsorship

If you find mergerfs useful please consider supporting its ongoing development.

lup (least used percentage) policy: selects the branch with the lowest used space percentage.
mount.mergerfs now includes the -n flag to support mounting without updating /etc/mtab.

Better lock management and behavior with open files. Reduction of contention.
Custom filename dedup strategy improving directory reading performance
Pre-calculate part of the file inode within readdir significantly reducing cost of overall calculation.
Replace sched_yield with nanosleep for improved scheduling of contention situations.
improved stat auto cache fingerprinting to reduce stale reads.

credential handling reworked to be compatible with chroot and idmap. removed ability to disable default_permissions option as a result as mergerfs now requires the kernel to manage entitlements.
broken mounts with ENOTCONN (common due to crashed FUSE instances) are automatically unmounted if possible on start instead of hard erroring. (mostly useful while developing).
fusermount3 will be used if available and other options missing.
remember-nodes option is deprecated and the feature removed. There is now only never-forget-nodes behavior. Any non-zero value in remember-nodes will enable never-forget-nodes. It was removed because time based really didn't save much memory and complicated the code. Doing this also reduced the size of each node helping offset increased node count.

fix race condition between runtime changing of branches and certain requests.
rmdir no longer returns success if any rmdir call returns ENOTEMPTY.
Invalid policy names are properly rejected.
statfs calculation could theoretically have overflowed with impossibly large branch values.
Fixed readlink buffer size management. The size does not include a nul terminating value.
Minor calculation bugs in copy_file_range and futimens.
moveonenospc no longer crashes when all destination branches are rejected. Returns ENOSPC.
Better / more proper error calculations in a number of functions.
rare ioctl call crash fixed