Summary:
While looking into the ESTALE issue, I was tracing through
the kernel code. I found that the root inode is set up with a generation
of 0 rather than 1 in this portion of the kernel code:
diffusion/LK/browse/v4.11-fb/fs/fuse/inode.c;abf7d7755299ee009f0c3cba40fcdcd038a212ac$650
The consequences of the generation being different are that the kernel
will report an ESTALE result when returning the dentry:
diffusion/LK/browse/v4.11-fb/fs/fuse/inode.c;abf7d7755299ee009f0c3cba40fcdcd038a212ac$690
This diff zero-initializes the entry result struct and explicitly sets the generation field to 0.
Sadly, this did not impact the manifestation of the ESTALE behavior that I've been running down.
It's also worth noting that the source of the `1` was from reading this comment in libfuse:
0a519c9772/include/fuse_lowlevel.h (L78-L79)
> The generation must be non-zero, otherwise FUSE will treat it as an error.
That isn't true of the kernel component.
Reviewed By: chadaustin
Differential Revision: D9944646
fbshipit-source-id: 9c1e2f4faec40a3aa446a4646d4518a854a1d73c
Summary:
Part of the larger project to modify Future<T>::then to be r-value qualified and use Future<T>::thenTry or Future<T>::thenValue.
The goal is to disambiguate folly::Future and to improve type and lifetime safety of Future and its methods.
Codemod:
future<T>.then(callable with operator()(not-a-try)) to future<T>.thenValue(callable with operator()(not-a-try)).
future<T>.then(callable with operator()()) to future<T>.thenValue(callable with operator()(auto&&)).
future<T>.then(callable with operator()(auto)) to future<T>.thenValue(callable with operator()(auto)).
future<T>.then(callable with operator()(folly::Try<T>)) to future<T>.thenTry(callable)
Reviewed By: Orvid
Differential Revision: D9819578
fbshipit-source-id: f9e31f47354c041ecbf0a90953cbe50ebfda6adc
Summary:
Overall plan to modify Future<T>::then to be r-value qualified and use Future<T>::thenTry or Future<T>::thenValue.
The goal is to disambiguate folly::Future and to improve type and lifetime safety of Future and its methods.
6/n: Codemod rvalue-future<T>.then(...) to rvalue-future<T>.then(...).
Reviewed By: yfeldblum
Differential Revision: D9152002
fbshipit-source-id: 166475c1dcafb29a11154cbfbdf7e2e1feaf745b
Summary:
Sometimes, Eden's overlay (in `$client_dir/local/`) gets corrupt. In
particular, sometimes overlay files can be truncated or missing after a hard
reboot where the underlying filesystem state was not flushed to disk.
For such files, open(), stat(), unlink(), etc. from Eden report ENOENT, yet
readdir() on the containing directory shows that the file does exist.
In other words, the problematic file is undeletable:
```
$ ls -la dir/
/bin/ls: cannot access dir/corrupt_file: No such file or directory
total 0
drwxr-xr-x. 3 strager 0 Jul 10 21:41 .
drwxr-xr-x. 48 strager 0 Jul 10 21:41 ..
-?????????? ? ? ? ? corrupt_file
$ rm dir/corrupt_file
rm: cannot remove ‘dir/corrupt_file’: No such file or directory
```
Allow users to delete these problematic files (if the file was a regular file
and not a directory) by doing the following:
* Allow corrupt regular files to be unlink()d successfully.
* Allow corrupt regular files to be stat()d.
Making stat() succeed is a requirement by FUSE:
* For unlink(), FUSE performs FUSE_LOOKUP before FUSE_UNLINK. If FUSE_LOOKUP
fails, unlink() fails. Therefore, we must make FUSE_LOOKUP succeed for
corrupt files.
* For stat(), FUSE performs FUSE_LOOKUP and sometimes FUSE_GETATTR. Since we
must make FUSE_LOOKUP succeed (for unlink()), it's natural to make
FUSE_GETATTR succeed too.
A future diff will fix corrupted directories.
Reviewed By: chadaustin
Differential Revision: D8884793
fbshipit-source-id: 1100037bf52475fcca66f39946b917ce604f12dc
Summary:
Overall plan to modify Future<T>::then to be r-value qualified and use Future<T>::thenTry or Future<T>::thenValue.
The goal is to disambiguate folly::Future and to improve type and lifetime safety of Future and its methods.
3/n: Codemod rvalue-future<T>.then(callable with operator()(not-a-try)) to rvalue-future<T>.thenValue(callable with operator()(not-a-try)).
Reviewed By: yfeldblum
Differential Revision: D8986716
fbshipit-source-id: 906339d9ffb90b3c38a24ce8bf0cef7be318d946
Summary:
1. Enabled a number of additional C++ compiler warnings in Eden.
2. Fixed warnings-turned-errors that resulted from this change.
Reviewed By: simpkins
Differential Revision: D8132543
fbshipit-source-id: 2290ffaaab55024d582e29201a1bcaa1152e6b3e
Summary:
Most filesystems limit path components to 255. To remain consistent,
let's have Eden do the same, at least for write operations.
Reviewed By: simpkins
Differential Revision: D8151020
fbshipit-source-id: 251da94a076f5765111c8e3d9d8a25c37682e2e3
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:
To avoid bugs similar to the ones fixed in D7781691, mark a bunch of
folly::Future<folly::Unit> functions with FOLLY_NODISCARD.
Reviewed By: simpkins
Differential Revision: D7782224
fbshipit-source-id: 23ba42aa63011cc33e5a6e18d5bc6d00403a78d3
Summary:
Disallow any kind of mutation operation inside of the .eden directory. We had some
code in place to prevent some of this already, but errors (including EPERM) weren't
passed out from unlink and rename out to FUSE.
Reviewed By: simpkins
Differential Revision: D7781691
fbshipit-source-id: aaecf13779eca75d6ee8765fc8bb3727ce9341de
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:
This helps distinguish `facebook::eden::FileHandle` from
`facebook::eden::fusell::FileHandle`, and will make it possible to eliminate
the separate `facebook::eden::fusell` namespace in the future.
Reviewed By: chadaustin
Differential Revision: D7314456
fbshipit-source-id: 0869427766fe666d119a59c7df1c97825a8ad36e
Summary:
I'm seeing test failures that I have not yet understood and I
thought they might be caused by an implicit conversion from
fusell::InodeNumber to bool. Well, they're not, but this is how I
discovered that. I'm not sure I want to land this change, but I'm
going to leave it around until I figure out what's happening with my
other diffs.
Reviewed By: simpkins
Differential Revision: D7077635
fbshipit-source-id: 50bf67026d2d0da0220c4709e3db24d841960f4b
Summary:
Previously we returned an ENOENT error in response to a FUSE lookup() call for
a name that does not exist. However, this does not allow FUSE to cache the
result, so we will continue to receive lookup() calls for this path in the
future.
This changes EdenDispatcher to return a successful response with an inode
number of 0 instead. This tells the kernel that the name does not exist, but
allows the kernel to cache this negative lookup result (for as long as
specified in the entry_valid field in the response).
Reviewed By: wez
Differential Revision: D7076811
fbshipit-source-id: a2b9977e58d6b6eecb584699b9d93b5ad29ad5ad
Summary:
This diff moves the mount-time initialization handling
out of the main loop. This rationale for this is:
* We don't (and shouldn't!) need to process FUSE_INIT for takeover
processing, and this structure allows us to make stronger assertions
about our state.
* we can avoid spinning up multiple threads in the (rare!) case that
the FUSE_INIT fails
* It is now a little harder for exceptions during initialization to
escape our notice.
In rearranging this stuff, I found a race condition in the worker thread
shutdown; we could erroneously emit a completion event before all of
the threads had been torn down and this resulted in sporadic integration
test failures hitting the assertion for the number of joined threads
in the destructor.
Reviewed By: simpkins
Differential Revision: D6766330
fbshipit-source-id: 32afb5a7c739c75aebfdb0a8f896eec5f41ad33f
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:
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:
CodeMod: Replace `wangle/concurrency` with `folly/executors`.
The headers in `wangle/concurrency/` are now but shims to equivalent headers in `folly/executors/`.
Reviewed By: jsedgwick
Differential Revision: D6120852
fbshipit-source-id: 358ceabea7ad79f84b803ed8e3aecb2a57fdd077
Summary:
CodeMod: Change `#include`'s of `wangle/concurrent/GlobalExecutor.h` to use `folly`.
The file in `wangle/` is just a shim around the same file in `folly/executors/GlobalExecutor.h`. Just codemod all the `#include` sites.
Reviewed By: Orvid
Differential Revision: D5981467
fbshipit-source-id: ad7f0dce959e2760d3977b04925945e0447abc1d
Summary:
This is a mechanical and dumb move of the code from MountPoint
and into the EdenMount class.
Of note, it doesn't merge together the two different state/status fields
into a unified thing; that will be tackled in a follow on diff.
Reviewed By: bolinfest
Differential Revision: D5778212
fbshipit-source-id: 6e91a90a5cc760429d87a475ec12f81b93f87be0
Summary:
This is leading up to folding the MountPoint code into
the EdenMount class.
There's still a mention of the MountPoint in Dispatcher.h; that is
being dealt with in the following diff.
Reviewed By: bolinfest
Differential Revision: D5778215
fbshipit-source-id: 996640b3773988a4738ad55bb13de45e1ffe1880
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:
Make a few minor tweaks to the strace-style logging added in D5464387.
- Call the log categories "eden.strace.<mount_path>" instead of
"eden/strace<mount_path>". The folly logging library uses '.' to separate
nodes in the log category hierarchy, so this puts all of the strace messages
under the "eden.strace" category, which it itself part of the "eden"
category. The "<mount_path>" will contain slashes inside it, but slashes are
not treated specially in log category names.
- Rename `EdenMount::getLogger()` to `EdenMount::getStraceLogger()` since this
logger should be used only for strace-style events, and not for general log
messages for this mount point.
Reviewed By: bolinfest
Differential Revision: D5515245
fbshipit-source-id: 9d833d9fbff47c6a57a7afefeae92755ff0e28b7
Summary:
Log messages to an eden.strace category.
This allows us to enable/disable based on the mount_path. For example:
./buck-out/gen/eden/cli/cli.par daemon -F -- --logging eden/strace/data/users/ekent/eden-NEW=DBG7
Thus, we are using a category, rather than filename (default)
Reviewed By: bolinfest
Differential Revision: D5464387
fbshipit-source-id: 6a54badd6bb806cfcda1742fd970073d91303396
Summary:
this code was present to help in some benchmarking
in the very early prototype code. I noticed that this was
still lingering when reviewing a diff the other day.
Remove it!
Reviewed By: simpkins
Differential Revision: D5334263
fbshipit-source-id: 9ecccf1f9922b4c8f46b2529da665e2fdf11ab7a
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:
These files are defining flags, so they should import gflags.
This import being missing causes open source build to fail.
Reviewed By: bolinfest
Differential Revision: D4992246
fbshipit-source-id: 61eb35b43ae6f9ff88bd34a9ebc8db6d80ac9d08
Summary:
Update Dirstate::remove() to directly call TreeInode::unlink() instead of going
through the EdenDispatcher. Internal code should be able to use TreeInode
directly without going through the FUSE Dispatcher. This prevents us from
having to look up the TreeInode object by inode number again.
This also fixes TreeInode::unlink() and TreeInode::rmdir() to perform FUSE
cache invalidation correctly. EdenDispatcher used to do this for unlink()
calls, but it was missing for rmdir() calls.
Reviewed By: wez
Differential Revision: D4968832
fbshipit-source-id: 51fda5de196392c640436ca6ad7d8333e6799db9
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
Summary:
Tweaks the stats stuff so that we can name the histograms and export them with p50, p90, p99 percentiles.
This is made a bit ugly because the fb303 stats code isn't yet open source, so
there's a moderately ugly preprocessor directive that we assume to be true for
our internal build. We'll need to force that to be 0 for the open source build
until we open the stats code and make it available.
Reviewed By: bolinfest
Differential Revision: D4801868
fbshipit-source-id: 643909e63bd4a74b2cfa580be131f65c5673bc94
Summary:
this is the bare minimum to support creating unix domain sockets.
We only support using mknod to create a unix socket; other uses will yield an error.
I've added an rdev field as a sibling of the existing mode field that we track,
as that is the additional parameter that we need to track as part of the
special file node.
Special file nodes are tracked in the overlay as empty files.
Reviewed By: bolinfest
Differential Revision: D4774099
fbshipit-source-id: 0824b7e509063faa8bede7aff82a7c51930c4f83
Summary:
Previously, we would only allow you to consume a symlink that was
checked into a revision, but not allow you to create a new one.
This diff adds support for making new symlinks.
It turns out that the code that we had for readlink had an unused code path for
reading an actual symlink out of the overlay. My first pass at this diff tried
to make the materialization code generate such a symlink, but it was breakin
some other assumptions in the rest of the code.
This version of the code just stores the symlink target in the file contents.
This means that we can simplify readlink to just calling `readAll` on the
underlying file data, and that will load the contents out of the storage layer
if the file wasn't materialized. This helps simplify things a bit more.
Reviewed By: bolinfest, simpkins
Differential Revision: D4604016
fbshipit-source-id: 3138d0f9880639d2bbeaf4bb03bef3f021c3ecb3
Summary:
Thesis: Since we don't yet have `hg update` implemented, these attributes can be cached forever.
When we implement `hg update` we will explicitly inform the kernel to invalidate anyway.
... and it turns out that the `scmRemove` thrift call is making changes that
aren't visible to the kernel already so we need to hook up some basic
invalidation.
This diff includes the bare minimum code to facilitate this; I've added a
helper method to the fusell::RequestData class to test whether we are in the
context of a FUSE request.
In the EdenDispatcher::unlink method we need to explicitly invalidate if we are
not being called via FUSE.
I have mixed feelings about putting this code in here. Given the initial
mental model I had in the prototype, this is the right place to put it, but it
does mean that all tree mutations must have via the Dispatcher in order for
invalidations to be routed to the correct places. Do we want to move away from
this?
It wouldn't be the end of the world to expand this diff a bit to add
similar/appropriate invalidation calls to all the mutation methods in our
dispatcher implementations while we figure out if we want to keep this.
Reviewed By: simpkins
Differential Revision: D4452961
fbshipit-source-id: 9471f145242fce0620c6872b74b02c56c8d78af1
Summary:
Update copyright statements to "2016-present". This makes our updated lint
rules happy and complies with the recommended license header statement.
Reviewed By: wez, bolinfest
Differential Revision: D4433594
fbshipit-source-id: e9ecb1c1fc66e4ec49c1f046c6a98d425b13bc27
Summary:
This updates the InodePtr and InodeBase code to actually implement Inode
unloading and destruction.
At the moment we keep Inode objects as long as possible, and only unload them
during shutdown, or when the last reference to an unlinked inode goes away.
However, it should be straightforward to add on-demand unloading in the future
for Inodes that have not been accessed in a while. The
TreeInode::unloadChildrenNow() function provides a template for what this would
look like (it would simply need to be changed to check an access time when
doing on-demand unloading).
Reviewed By: wez
Differential Revision: D4360765
fbshipit-source-id: a46b355f0ac0c25f873a156e62af5184317de735
Summary:
Add VLOG() statements for every FUSE entry point. Turning up the VLOG level in
EdenDispatcher now allows us to have a record of all FUSE calls made using
inode numbers. (Calls involving file handles or directory handles currently go
directly to the handle in question and do not pass through the EdenDispatcher.
We should probably add log statements for those too, but that can wait for a
later diff.)
Reviewed By: bolinfest
Differential Revision: D4359066
fbshipit-source-id: b378d829c39fdb61faf63d2d400f3ff556c376e8
Summary:
This updates all of the eden code to use the new InodeMap class. This replaces
the InodeNameManager class and the unordered_map previously stored in the
EdenDispatcher.
Reviewed By: bolinfest
Differential Revision: D4325750
fbshipit-source-id: d80ae7581ba79ca2b63155e184995a3e83e85dc1
Summary:
Fix Dispatcher::symlink() to accept the symlink contents as a StringPiece
rather than a PathComponentPiece. symlink contents can be any arbitrary
string, and are not required to be a valid, normalized path name.
Reviewed By: wez
Differential Revision: D4325380
fbshipit-source-id: 88448bee50ea192c06442dc70042c7d17d49a12f
Summary:
Define InodePtr, TreeInodePtr, and FileInodePtr as aliases for std::shared_ptr
of the underlying inode type. This also updates all of the code to use these
new type names.
This will make it easier swap out std::shared_ptr with a custom pointer type in
the future. (I believe we will need a custom type in the future so that we
can have more precise control of the reference counting so we can load and
unload Inode objects on demand. std::shared_ptr::unique() doesn't quite
provide the flexibility we need, and is also being deprecated in C++17.)
Reviewed By: bolinfest
Differential Revision: D4297791
fbshipit-source-id: 1080945649290e676f62689592159f1166159b20
Summary:
Move the InodeBase class from the lower-level fusell code up to the
eden/fs/inodes layer, now that everything else that uses it is in
eden/fs/inodes.
I plan to start changing the ownership model of inode objects a bit, and this
will allow the InodeBase class to interact with EdenDispatcher and other
classes in eden/fs/inodes.
Reviewed By: bolinfest
Differential Revision: D4283392
fbshipit-source-id: 9e1d6fb81dc223f905847cbe8d165a40ad0aca4d
Summary:
Now that the EdenDispatcher class has been moved into eden/fs, we no longer
need the distinction between TreeInode and fusell::DirInode, and FileInode and
fusell::FileInode.
This diff deletes the fusell versions of these classes, and updates all of the
code to always directly use TreeInode and FileInode. This allows us to get rid
of the remaining dynamic_casts between these pairs of classes.
Reviewed By: bolinfest
Differential Revision: D4257165
fbshipit-source-id: e2b6f328b9605ca0e2882f5cf7a3983fb4470cdf
Summary:
Move the InodeDispatcher class out of the lower-level fusell namespace in
eden/fuse and into the higher-level eden code in eden/fs/inodes. I also
renamed it from InodeDispatcher to EdenDispatcher, in anticipation of it
getting more eden-specific functionality in the future.
The fusell::MountPoint class is now independent of the Dispatcher type, and can
work with any Dispatcher subclass. Previously the MountPoint class was
responsible for owning the InodeDispatcher object. Now its caller (EdenMount
in our case) is responsible for supplying a Dispatcher object that is owned
externally.
Several parts of EdenDispatcher had to be updated as a result of the namespace
move, but I tried to keep this change somewhat minimal. I did update it from
using fusell::DirInode and fusell::FileInode to eden's TreeInode and FileInode
classes directly. However, there still remains more clean-up work to do. I
will split remaining changes out into upcoming diffs.
Reviewed By: bolinfest
Differential Revision: D4257163
fbshipit-source-id: dc9c2526640798f9f924ae2531218ba2c45d1d0a
