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6ff492d11c
Summary: This serves a few purposes: 1. We can avoid some conditional code inside eden if we know that we have a specific fuse_kernel.h header implementation. 2. We don't have to figure out a way to propagate the kernel capabilities through the graceful restart process. 3. libfuse3 removed the channel/session hooks that we've been using thus far to interject ourselves for mounting and graceful restarting, so we were already effectively the walking dead here. 4. We're now able to take advtange of the latest aspects of the fuse kernel interface without being tied to the implementation of libfuse2 or libfuse3. We're interested in the readdirplus functionality and will look at enabling that in a future diff. This may make some things slightly harder for the more immediate macOS port but I belive that we're in a much better place overall. This diff is relatively mechanical and sadly is (unavoidably) large. The main aspects of this diff are: 1. The `fuse_ino_t` type was provided by libfuse so we needed to replace it with our own definition. This has decent penetration throughout the codebase. 2. The confusing `fuse_file_info` type that was multi-purpose and had fields that were sometimes *in* parameters and sometimes *out* parameters has been removed and replaced with a simpler *flags* parameter that corresponds to the `open(2)` flags parameter. The *out* portions are subsumed by existing file handle metadata methods. 3. The fuse parameters returned from variations of the `LOOKUP` opcode now return the fuse kernel type for this directly. I suspect that we may need to introduce a compatibility type when we revisit the macOS port, but this at least makes this diff slightly simpler. You'll notice that some field and symbol name prefixes vary as a result of this. 4. Similarly for `setattr`, libfuse separated the kernel data into two parameters that were a little awkward to use; we're now just passing the kernel data through and this, IMO, makes the interface slightly more understandable. 5. The bulk of the code from `Dispatcher.cpp` that shimmed the libfuse callbacks into the C++ virtual methods has been removed and replaced by a `switch` statement based dispatcher in `FuseChannel`. I'm not married to this being `switch` based and may revise this to be driven by an `unordered_map` of opcode -> dispatcher method defined in `FuseChannel`. Regardless, `Dispatcher.cpp` is now much slimmer and should be easier to replace by rolling it together into `EdenDispatcher.cpp` in the future should we desire to do so. 6. This diff disables dispatching `poll` and `ioctl` calls. We didn't make use of them and their interfaces are a bit fiddly. 7. `INTERRUPT` is also disabled here. I will re-enable it in a follow-up diff where I can also revise how we track outstanding requests for graceful shutdown. 8. I've imported `fuse_kernel.h` from libfuse. This is included under the permissive 2-clause BSD license that it allows for exactly this integration purpose. Reviewed By: simpkins Differential Revision: D6576472 fbshipit-source-id: 7cb088af5e06fe27bf22a1bed295c18c17d8006c
6 lines
148 B
Plaintext
6 lines
148 B
Plaintext
cpp_library(
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name = "fuse_kernel",
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# TODO: conditionally pull in fuse_kernel_macos.h here on macos
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headers = ["fuse_kernel_linux.h"],
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)
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