Summary:
This is really a continuation of D13479516; the issue is that
the osxfuse kernel module is very eager to recycle `unique` request
id values, recycling them before our code has had a chance to update
internal state.
This diff re-keys the requests map so that we generate our own sequence
of identifiers to use as the key rather than the fuse protocol `unique`
value.
Because we cannot reliably track by `unique` value we also cannot
reliably implement interrupt support. We've never really tested
interrupt support, and it relies on functionality in folly futures
that hasn't really been tested or proven either, so I've removed
that functionality as part of this diff.
That allows simplifying some code in RequestData and FuseChannel;
we're now able to simply tack an `.ensure` on the end of the
future chain to ensure that we remove the entry from the map
once the future is resolved, successfully or otherwise.
Reviewed By: chadaustin
Differential Revision: D13679964
fbshipit-source-id: c1081a868c4061de2a725589ec1614959a8e9316
Summary: While looking at FuseChannel I noticed an unnecessary Future.
Reviewed By: strager
Differential Revision: D9595672
fbshipit-source-id: 5c84822c4f2c4c3c78b88456e44728e463d5a1e8
Summary:
Fixed a data race in Eden's `FuseChannel` implementation that could cause a crash if a `FUSE_INTERRUPT` request was concurrently on a different thread while a first thread was still launching the original request.
Modified `FakeFuse` to use `SOCK_SEQPACKET` instead of `SOCK_STREAM` so that tests can submit several requests in a pipelined fashion without having to first wait until the previous request was received. This requires the `recvResponse()` function to first read the header with `MSG_PEEK` to determine the response size and then subsequently read the entire message atomically to avoid reading a truncated message.
Added a new unit-test that exercises the `FUSE_INTERRUPT` race condition by sending a series of alternating `FUSE_LOOKUP`/`FUSE_INTERRUPT` requests.
Reviewed By: simpkins
Differential Revision: D9023654
fbshipit-source-id: 0eb44669ea8c4f58cf4313adf6ceb11098115a70
Summary:
Per yfeldblum's comment in D7886046, we can use folly::unit instead
of folly::Unit{}. We weren't using folly::unit anywhere, so this diff
replaces folly::Unit{} elsewhere in the Eden code.
Reviewed By: yfeldblum
Differential Revision: D7913462
fbshipit-source-id: fa6ab44ceb406d38713e0f4649224a74e6e51abd
Summary:
Promote the folly logging code out of the experimental subdirectory.
We have been using this for several months in a few projects and are pretty
happy with it so far.
After moving it out of the experimental/ subdirectory I plan to update
folly::Init() to automatically support configuring it via a `--logging` command
line flag (similar to the initialization it already does today for glog).
Reviewed By: yfeldblum, chadaustin
Differential Revision: D7755455
fbshipit-source-id: 052db34c97f7516728f7cbb1a5ad959def2f6efb
Summary:
Add a new utils/SystemError.h header with helper functions to check if a
`std::system_error` contains an errno value.
Most of the code in Eden previously only checked for `std::system_category`
when looking for errno values. `std::generic_category` is the correct category
to use for errno exceptions, but folly/Exception.h incorrectly throws them as
`std::system_category` today. This change makes Eden treat either error type
as errno values for now.
Reviewed By: yfeldblum
Differential Revision: D7329999
fbshipit-source-id: 67a3c3ea10371c53a2e34236b7575deac4cbd53a
Summary:
Added a thrift call to return the outstanding FUSE requests.
Cli will call the thrift and print the output.
Added a unit test to test getOutstandingRequests().
Reviewed By: simpkins
Differential Revision: D7314584
fbshipit-source-id: 420790405babdb734f598e19719b487096ec53ca
Summary:
Eliminate a few unnecessary includes from Dispatcher.h and one from
RequestData.h
Reviewed By: wez
Differential Revision: D7300846
fbshipit-source-id: 0cde1f70f605fcb5c95ed13950f4fa8d353fd72f
Summary:
Now that we have full control over the fuse session,
moving the threads here makes a lot of sense and makes things
easier from an overall state management perspective.
FuseChannel now provides a future that make it easier for EdenMount to wait
until all the threads and outstanding requests have completed.
There is also a future to determine when the first of the threads
has exited which is used to detect an error condition. We could
go a bit further with this and have the error condition propagate
out from our dispatcher, but that's a bit further away from my
goal of making the graceful restart stuff work.
I've removed the request counting stuff from Dispatcher as we
can now use the definitive signals from FuseChannel in its place.
Reviewed By: chadaustin
Differential Revision: D6580247
fbshipit-source-id: 6bcc3b8b531d59a3fdd0ca6fd09410ad64f8221a
Summary:
I'm mostly interested in this as the definitive way to know
how many outstanding fuse requests there are, which is important
for synchronization for graceful restart.
An important part of this diff is to use of the `RequestContextScopeGuard`.
Previously, `RequestData::create` would implicitly create a new
`folly::RequestContext` and associate it with the current thread each
time a new request was processed on the fuse worker thread. Critically,
it would never take any action to remove that association. What that
meant was that during shutdown some number of fuse worker threads were
extending the lifetime of some fuse requests and that leads either to
an use-after-free (as is the case in this diff stack up until this diff),
or with the stronger synchronization that we desire in graceful restarts,
a deadlock.
Reviewed By: chadaustin
Differential Revision: D6578933
fbshipit-source-id: f82f75e75a398d1f6beacb9466060e7bd99adbc1
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
Summary:
this is a backport of the same fix from D6578933 and helps
to avoid noise with our new default ASAN enabled build settings.
The root of the problem is that we didn't guarantee to clear the
association between the fuse worker thread and a folly request
associated with a fuse request. This meant that the lifetime
of the RequestData was being extended until after the EdenMount
was destroyed and then the destructor of RequestData would trigger
an access inside the EdenMount instance.
Adopting the `RequestContextScopeGuard` type helps to avoid this,
at the cost of perhaps prematurely heap allocating a request context
for some opcodes. D6578933 can avoid that cost.
Reviewed By: chadaustin
Differential Revision: D6602416
fbshipit-source-id: 80785b860af906c0fcf02b42f0235796377c265f
Summary:
Per discussion with bolinfest, this brings Eden in line with clang-format.
This diff was generated with `find . \( -iname '*.cpp' -o -iname '*.h' \) -exec bash -c "yes | arc lint {}" \;`
Reviewed By: bolinfest
Differential Revision: D6232695
fbshipit-source-id: d54942bf1c69b5b0dcd4df629f1f2d5538c9e28c
Summary:
We'll need to gate portions of our shutdown so that we don't
tear down the database until after in-flight requests have completed.
This seems like the easiest way to go about it.
Reviewed By: simpkins
Differential Revision: D5796593
fbshipit-source-id: 49e695826ae68cc2b1d724a8da53ce5d884ff9ff
Summary:
The higher level goal is to make it easier to deal
with the graceful restart scenario.
This diff removes the SessionDeleter class and effectively renames
the Channel class to FuseChannel. The FuseChannel represents
the channel to the kernel; it can be constructed from a fuse
device descriptor that has been obtained either from the privhelper
at mount time, or from the graceful restart procedure. Importantly
for graceful restart, it is possible to move the fuse device
descriptor out of the FuseChannel so that it can be transferred
to a new eden process.
The graceful restart procedure requires a bit more control over
the lifecycle of the fuse event loop so this diff also takes over
managing the thread pool for the worker threads. The threads
are owned by the MountPoint class which continues to be responsible
for starting and stopping the fuse session and notifying EdenServer
when it has finished. A nice side effect of this change is that
we can remove a couple of inelegant aspects of the integration;
the stack size env var stuff and the redundant extra thread
to wait for the loop to finish.
I opted to expose the dispatcher ops struct via an `extern` to
simplify the code in the MountPoint class and avoid adding special
interfaces for passing the ops around; they're constant anyway
so this doesn't feel especially egregious.
Reviewed By: bolinfest
Differential Revision: D5751521
fbshipit-source-id: 5ba4fff48f3efb31a809adfc7787555711f649c9
Summary:
Update all of the code using ThreadLocal<EdenStats> to pass in a non-default
Tag parameter to the ThreadLocal template.
A non-default tag parameter is required to use the accessAllThreads() method on
the ThreadLocal object. We need to use accessAllThreads() to perform stats
aggregation correctly. Currently the EdenServer code is only performing
aggregation for stats in the FunctionScheduler.
This diff only updates the ThreadLocal<EdenStats> type, but does not contain
any behavior changes. I will fix the stats aggregation in a subsequent diff.
Reviewed By: bolinfest
Differential Revision: D5657268
fbshipit-source-id: bc4b6f56324eb8d3052c023fd3f6f64f99b1d4e0
Summary: This uses `clang-tidy` to comment out unused parameters (in functions, methods and lambdas) in fbcode. Cases that the tool failed to handle are fixed manually.
Reviewed By: igorsugak
Differential Revision: D5454343
fbshipit-source-id: 5dee339b4334e25e963891b519a5aa81fbf627b2
Summary:
Update eden to log via the new folly logging APIs rather than with glog.
This adds a new --logging flag that takes a logging configuration string.
By default we set the log level to INFO for all eden logs, and WARNING for
everything else. (I suspect we may eventually want to run with some
high-priority debug logs enabled for some or all of eden, but this seems like a
reasonable default to start with.)
Reviewed By: wez
Differential Revision: D5290783
fbshipit-source-id: 14183489c48c96613e2aca0f513bfa82fd9798c7
Summary:
This change makes it so that all of the C++ code related to the edenfs daemon
is now contained in the eden/fs subdirectory.
Reviewed By: bolinfest, wez
Differential Revision: D4889053
fbshipit-source-id: d0bd4774cc0bdb5d1d6b6f47d716ecae52391f37
