8b857eef9c
* Ship Stargz Snapshotter Signed-off-by: ktock <ktokunaga.mail@gmail.com> * Bump github.com/containerd/stargz-snapshotter to v0.8.0 Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com> |
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| .. | ||
| api.go | ||
| bridge.go | ||
| constants_darwin.go | ||
| constants_linux.go | ||
| constants.go | ||
| default.go | ||
| dirstream_darwin.go | ||
| dirstream_linux.go | ||
| dirstream.go | ||
| files_darwin.go | ||
| files_linux.go | ||
| files.go | ||
| inode.go | ||
| loopback_darwin.go | ||
| loopback_linux.go | ||
| loopback.go | ||
| mem.go | ||
| mount.go | ||
| README.md | ||
| syscall_linux.go | ||
Objective
A high-performance FUSE API that minimizes pitfalls with writing correct filesystems.
Decisions
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Nodes contain references to their children. This is useful because most filesystems will need to construct tree-like structures.
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Nodes contain references to their parents. As a result, we can derive the path for each Inode, and there is no need for a separate PathFS.
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Nodes can be "persistent", meaning their lifetime is not under control of the kernel. This is useful for constructing FS trees in advance, rather than driven by LOOKUP.
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The NodeID for FS tree node must be defined on creation and are immutable. By contrast, reusing NodeIds (eg. rsc/bazil FUSE, as well as old go-fuse/fuse/nodefs) needs extra synchronization to avoid races with notify and FORGET, and makes handling the inode Generation more complicated.
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The mode of an Inode is defined on creation. Files cannot change type during their lifetime. This also prevents the common error of forgetting to return the filetype in Lookup/GetAttr.
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The NodeID (used for communicating with kernel) is equal to Attr.Ino (value shown in Stat and Lstat return values.).
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No global treelock, to ensure scalability.
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Support for hard links. libfuse doesn't support this in the high-level API. Extra care for race conditions is needed when looking up the same file through different paths.
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do not issue Notify{Entry,Delete} as part of AddChild/RmChild/MvChild: because NodeIDs are unique and immutable, there is no confusion about which nodes are invalidated, and the notification doesn't have to happen under lock.
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Directory reading uses the DirStream. Semantics for rewinding directory reads, and adding files after opening (but before reading) are handled automatically. No support for directory seeks.
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Method names are based on syscall names. Where there is no syscall (eg. "open directory"), we bias towards writing everything together (Opendir)
To do/To decide
- Symlink []byte vs string.