/dev/fuse was already pollable with poll and select. Add support for
kqueue, too. And add tests for polling with poll, select, and kqueue.
Sponsored by: The FreeBSD Foundation
When a FUSE daemon dies or closes /dev/fuse, all of that daemon's pending
requests must be terminated. Previously that was done in /dev/fuse's
.d_close method. However, d_close only gets called on the *last* close of
the device. That means that if multiple daemons were running concurrently,
all but the last daemon to close would leave their I/O hanging around. The
problem was easily visible just by running "kyua -v parallelism=2 test" in
fusefs's test directory.
Fix this bug by terminating a daemon's pending I/O during /dev/fuse's
cdvpriv dtor method instead. That method runs on every close of a file.
Also, fix some potential races in the tests:
* Clear SA_RESTART when registering the daemon's signal handler so read(2)
will return EINTR.
* Wait for the daemon to die before unmounting the mountpoint, so we won't
see an unwanted FUSE_DESTROY operation in the mock file system.
Sponsored by: The FreeBSD Foundation
* If a process receives a fatal signal while blocked on a fuse operation,
return ASAP without waiting for the operation to complete. But still send
the FUSE_INTERRUPT op to the daemon.
* Plug memory leaks from r346339
Interruptibility is now fully functional, but it could be better:
* Operations that haven't been sent to the server yet should be aborted
without sending FUSE_INTERRUPT.
* It would be great if write operations could be made restartable.
That would require delaying uiomove until the last possible moment, which
would be sometime during fuse_device_read.
* It would be nice if we didn't have to guess which EAGAIN responses were
for FUSE_INTERRUPT operations.
PR: 236530
Sponsored by: The FreeBSD Foundation
The fuse protocol includes a FUSE_INTERRUPT operation that the client can
send to the server to indicate that it wants to abort an in-progress
operation. It's required to interrupt any syscall that is blocking on a
fuse operation.
This commit adds basic FUSE_INTERRUPT support. If a process receives any
signal while it's blocking on a FUSE operation, it will send a
FUSE_INTERRUPT and wait for the original operation to complete. But there
is still much to do:
* The current code will leak memory if the server ignores FUSE_INTERRUPT,
which many do. It will also leak memory if the server completes the
original operation before it receives the FUSE_INTERRUPT.
* An interrupted read(2) will incorrectly appear to be successful.
* fusefs should return immediately for fatal signals.
* Operations that haven't been sent to the server yet should be aborted
without sending FUSE_INTERRUPT.
* Test coverage should be better.
* It would be great if write operations could be made restartable.
That would require delaying uiomove until the last possible moment, which
would be sometime during fuse_device_read.
PR: 236530
Sponsored by: The FreeBSD Foundation
The fuse protocol is designed with security in mind. It prevents users from
spying on each others' activities. And it doesn't grant users any
privileges that they didn't already have. So it's appropriate to make it
available to everyone. Plus, it's necessary in order for kyua to run tests
as an unprivileged user.
Sponsored by: The FreeBSD Foundation
fuse(4) was heavily instrumented with debug printf statements that could
only be enabled with compile-time flags. They fell into three basic groups:
1) Totally redundant with dtrace FBT probes. These I deleted.
2) Print textual information, usually error messages. These I converted to
SDT probes of the form fuse:fuse:FILE:trace. They work just like the old
printf statements except they can be enabled at runtime with dtrace.
They can be filtered by FILE and/or by priority.
3) More complicated probes that print detailed information. These I
converted into ad-hoc SDT probes.
Sponsored by: The FreeBSD Foundation
Take a pass through fixing some of the most egregious whitespace issues in
fs/fuse. Also fix some style(9) warts while here. Not 100% cleaned up, but
somewhat less painful to look at and edit.
No functional change.
Mainly focus on files that use BSD 3-Clause license.
The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
This has been developed during 2 summer of code mandates and being revived
by gnn recently.
The functionality in this commit mirrors entirely content of fusefs-kmod
port, which doesn't need to be installed anymore for -CURRENT setups.
In order to get some sparse technical notes, please refer to:
http://lists.freebsd.org/pipermail/freebsd-fs/2012-March/013876.html
or to the project branch:
svn://svn.freebsd.org/base/projects/fuse/
which also contains granular history of changes happened during port
refinements. This commit does not came from the branch reintegration
itself because it seems svn is not behaving properly for this functionaly
at the moment.
Partly Sponsored by: Google, Summer of Code program 2005, 2011
Originally submitted by: ilya, Csaba Henk <csaba-ml AT creo DOT hu >
In collabouration with: pho
Tested by: flo, gnn, Gustau Perez,
Kevin Oberman <rkoberman AT gmail DOT com>
MFC after: 2 months
