Change Summary

• Special case O_TMPFILE in preload. Fixes incorrect permissions when used.

Documentation

https://github.com/trapexit/mergerfs/blob/2.40.2/README.md

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Change Summary

• Fix intermittent error of EIO when used with NFS

Documentation

https://github.com/trapexit/mergerfs/blob/2.40.1/README.md

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Change Summary

After many hours of debugging it looks like mergerfs users have uncovered another kernel bug.

• Add export-support option as a possible workaround for NFS EIO issue. Set to false.
  • https://github.com/trapexit/mergerfs?tab=readme-ov-file#export-support
• Add details to README regarding remote filesystems

Documentation

https://github.com/trapexit/mergerfs/blob/2.40.0/README.md

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Change Summary

• Changed flush-on-close to default to opened-for-write
• Fix user.mergerfs.pid queries
• Misc updates to docs
• Add experimental LD_PRELOAD library to provide faked passthrough: https://github.com/trapexit/mergerfs/blob/2.39.0/README.md#preloadso

Documentation

https://github.com/trapexit/mergerfs/blob/2.39.0/README.md

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Change Summary

• Improvement: Rework how threadpools queue depth. There was a rare bug that affected 1 user that lead to the pool believing there were no queue slots open when there should have been.
• Improvement: Better compatibility with older versions of MUSL.
• Improvement: Print warnings to stderr and syslog if run as non-root indicating mergerfs may not work correctly.
• Improvement: Change how allow_other auto-setting works. Only set if running as root for those users who are on shared hosts with user_allow_other disabled and all activity is done as their user id. There may still be edge cases that fail but if it works for them I don't want to disallow it.
• Add flushonclose feature. Takes advantage of a newer FUSE feature which gives the server control over if a flush is issued at file close. Defaults to a less aggressive policy of only flushing when a file is opened for write.

Documentation

https://github.com/trapexit/mergerfs/blob/2.38.0/README.md

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Change Summary

• Fix deadlock when exiting mergerfs

Documentation

https://github.com/trapexit/mergerfs/blob/2.37.1/README.md

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Change Summary

• readdir policies: func.readdir=X where X is seq, cor, or cosr.
  • seq: sequential - works same as before. Iterate over each branch in order configured.
  • cosr: concurrent open sequential read - dispatches requests to open directories to a thread pool and then reads directories sequentially the same way seq does.
  • cor: concurrent open and read - dispatches requests to a thread pool which both opens and reads directories concurrently.
  • thread pool sizes are configurable. cosr:5 would give you 5 threads.
  • see the docs for more info
• Add invalidation of gid cache via SIGUSR2 (which also triggers a full memory gc)

Changelog

• Lib updates by @trapexit in #1213
• Move fuse thread args out of fuse session object by @trapexit in #1219
• Fix logging pin-threads details by @trapexit in #1220
• Add readdir policies by @trapexit in #1224
• Add callbacks for newer functions by @trapexit in #1225
• Fix a typo in README.md by @feltcat in #1226
• Add ability to invalidate gid cache on demand by @trapexit in #1227
• Add thread names for easier debugging by @trapexit in #1228
• Fix setting of ugids for concurrent readdir by @trapexit in #1231
• Update wyhash to final4 by @trapexit in #1232
• Use relaxed memory order for atomic counters by @trapexit in #1233
• Misc fixes for older platforms by @trapexit in #1234
• Docs: clarify parallel-direct-writes and cache.files by @DavidFair in #1235
• Initialize readdir threadpool after daemonizing by @trapexit in #1237
• Change threadpool to use concurrentqueue by @trapexit in #1238
• Add proper input validation for readdir policy by @trapexit in #1239
• Rework thread pool, add ability to add/remove threads at runtime by @trapexit in #1240
• Add website and license to version option by @trapexit in #1241
• Remove unneeded debug logging from thread pool by @trapexit in #1242
• Add some new questions to FAQ by @trapexit in #1244

Documentation

https://github.com/trapexit/mergerfs/blob/2.37.0/README.md

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Change Summary

• Allow user to define depth of process thread message queues. Previously these were unbounded and "FORGET" message floods would bloat memory.
• O_DIRECT now supported, mostly. If software attempt to change the O_DIRECT flag on the fly using fcntl(F_SETFL) it won't work as that is not supported by FUSE.
• Fix bug in moveonenospc file moves when the file was opened in append mode.
• When a create function fails with EROFS (which really only happens when an ext4 filesystem errors) the relevant branch will be marked as mode = RO and the call tried again.
• Add ability to trigger memory cleanup via custom ioctl calls or signal SIGUSR2.
• Add ability to trigger invalidation of all nodes to flush memory using custom ioctl or signal SIGUSR1.

Changelog

• Fix crash when exiting with open deleted files by @trapexit in #1170
• Make srcmounts readonly by @trapexit in #1171
• Fix move when in append mode + fix read/write direct_io vs cached behavior by @trapexit in #1203
• Add manual GC triggering + configurable process queue depth by @trapexit in #1204
• Fix error handling for cached writes by @trapexit in #1206
• Fix build on older distros due to std::atomic definitions by @trapexit in #1207
• Simplify syslog wrapper a bit by @trapexit in #1208
• Align msg buffer memory to allow O_DIRECT to work by @trapexit in #1209
• Create functions can set branches RO on EROFS by @trapexit in #1212

Documentation

https://github.com/trapexit/mergerfs/blob/2.36.0/README.md

Donations / Sponsorship

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What's Changed

• Change default read-thread-count from -1 to 0 as documented by @trapexit in #1165
• Remove duplicate entries in docs by @trapexit in #1166

Documentation

https://github.com/trapexit/mergerfs/blob/2.35.1/README.md

Donations / Sponsorship

https://github.com/trapexit/support

Summary Changelog

• Lots of documentation changes and tweaks.
• Add ability to log to syslog. Used only for certain new features at startup.
• New FUSE message processing mode. Allow for a separation between threads which are reading messages and those processing messages. See process-thread-count option.
• Added ability to pin threads to physical or logical cores automatically. Numerous algorithms provided. Makes it easier to limit mergerfs' compute footprint while maintaining concurrency. See pin-threads option.
• Added ability to change mergerfs' scheduling priority (default has been -10). See scheduling-priority option.
• Added ability for mergerfs on startup only to wait for all branches to become a filesystem other than the mountpoint's. This is not a full replacement for proper dependency management via systemd or similar systems but can help. See branches-mount-timeout option.
• Try to catch and forbid adding the target mountpoint as a branch.
• Added ability to set branch AND mergerfs readahead from within mergerfs at startup. Larger values may improve performance when using page caching in particular. See readahead option.
• Added ability to lazily unmount the target mountpoint when started. This helps in live upgrades of mergerfs or instances where mount -a is run. This will allow the underlying instance of mergerfs to exit once it is no longer in use while the new instance is running on top of it.
• Added new cache.files policy per-process. Used with cache.files.process-names it can define process comm names that will have page caching enabled when matched.
• Reject all btrfs ioctl calls made to mergerfs.
• Optimized FUSE message handling to reduce memory allocation. Same with some internal functions like read.
• Removed need to set use_ino, nonempty, or allow_other. They should have been always enabled for proper functionality and compatibility. Setting them is a noop.
• Removed all splice features. Over the years there has been little evidence the feature actually improved performance but did complicate the code quite a bit. The splice options are now noops.

Documentation

https://github.com/trapexit/mergerfs/blob/2.35.0/README.md

Donations

https://github.com/trapexit/support

New Contributors

• @davidkaufman made their first contribution in #1116
• @jonaswinkler made their first contribution in #1146
• @kephir4eg made their first contribution in #1151

Full Changelog

2.34.1...2.35.0