Commit Graph

38 Commits

Author SHA1 Message Date
Alan Somers
427d205cb5 fusefs: remove superfluous counter_u64_zero
Reported by:	glebius
Sponsored by:	The FreeBSD Foundation
2019-08-06 00:50:25 +00:00
Alan Somers
ed74f781c9 fusefs: add a intr/nointr mount option
FUSE file systems can optionally support interrupting outstanding
operations.  However, the file system does not identify to the kernel at
mount time whether it's capable of doing that.  Instead it signals its
noncapability by returning ENOSYS to the first FUSE_INTERRUPT operation it
receives.  That's a problem for reliable signal delivery, because the kernel
must choose which thread should get a signal before it knows whether the
FUSE server can handle interrupts.  The problem is even worse because the
FUSE protocol allows a file system to simply ignore all FUSE_INTERRUPT
operations.

Fix the signal delivery logic by making interruptibility an opt-in mount
option.  This will require a corresponding change to libfuse, but not to
most file systems that link to libfuse.

Bump __FreeBSD_version due to the new mount option.

Sponsored by:	The FreeBSD Foundation
2019-07-18 17:55:13 +00:00
Alan Somers
f05962453e fusefs: fix another semi-infinite loop bug regarding signal handling
fticket_wait_answer would spin if it received an unhandled signal whose
default disposition is to terminate.  The reason is because msleep(9) would
return EINTR even for a masked signal.  One reason is when the thread is
stopped, which happens for example during sigexit().  Fix this bug by
returning immediately if fticket_wait_answer ever gets interrupted a second
time, for any reason.

Sponsored by:	The FreeBSD Foundation
2019-07-18 15:30:00 +00:00
Alan Somers
d26d63a4af fusefs: multiple interruptility improvements
1) Don't explicitly not mask SIGKILL.  kern_sigprocmask won't allow it to be
   masked, anyway.

2) Fix an infinite loop bug.  If a process received both a maskable signal
   lower than 9 (like SIGINT) and then received SIGKILL,
   fticket_wait_answer would spin.  msleep would immediately return EINTR,
   but cursig would return SIGINT, so the sleep would get retried.  Fix it
   by explicitly checking whether SIGKILL has been received.

3) Abandon the sig_isfatal optimization introduced by r346357.  That
   optimization would cause fticket_wait_answer to return immediately,
   without waiting for a response from the server, if the process were going
   to exit anyway.  However, it's vulnerable to a race:

   1) fatal signal is received while fticket_wait_answer is sleeping.
   2) fticket_wait_answer sends the FUSE_INTERRUPT operation.
   3) fticket_wait_answer determines that the signal was fatal and returns
      without waiting for a response.
   4) Another thread changes the signal to non-fatal.
   5) The first thread returns to userspace.  Instead of exiting, the
      process continues.
   6) The application receives EINTR, wrongly believes that the operation
      was successfully interrupted, and restarts it.  This could cause
      problems for non-idempotent operations like FUSE_RENAME.

Reported by:    kib (the race part)
Sponsored by:   The FreeBSD Foundation
2019-07-17 22:45:43 +00:00
Alan Somers
8aafc8c389 [skip ci] update copyright headers in fusefs files
Sponsored by:	The FreeBSD Foundation
2019-06-28 04:18:10 +00:00
Alan Somers
560a55d094 fusefs: convert statistical sysctls to use counter(9)
counter(9) is more performant than using atomic instructions to update
sysctls that just report statistics to userland.

Sponsored by:	The FreeBSD Foundation
2019-06-27 16:30:25 +00:00
Alan Somers
87ff949a7b fusefs: raise protocol level to 7.23
None of the new features are implemented yet.  This commit just adds the new
protocol definitions and adds backwards-compatibility code for pre 7.23
servers.

Sponsored by:	The FreeBSD Foundation
2019-06-21 04:57:23 +00:00
Alan Somers
a1c9f4ad0d fusefs: implement VOP_BMAP
If the fuse daemon supports FUSE_BMAP, then use that for the block mapping.
Otherwise, use the same technique used by vop_stdbmap.  Report large values
for runp and runb in order to maximize read clustering and minimize upcalls,
even if we don't know the true layout.

The major result of this change is that sequential reads to FUSE files will
now usually happen 128KB at a time instead of 64KB.

Sponsored by:	The FreeBSD Foundation
2019-06-20 17:08:21 +00:00
Alan Somers
93fecd02a1 fusefs: misc build fixes
* Only build the tests on platforms with C++14 support
* Fix an undefined symbol error on lint builds
* Remove an unused function: fiov_clear

Sponsored by:	The FreeBSD Foundation
2019-05-25 21:40:27 +00:00
Alan Somers
16bd2d47c7 fusefs: Upgrade FUSE protocol to version 7.9.
This commit upgrades the FUSE API to protocol 7.9 and adds unit tests for
backwards compatibility with servers built for version 7.8.  It doesn't
implement any of 7.9's new features yet.

Sponsored by:	The FreeBSD Foundation
2019-05-16 17:24:11 +00:00
Alan Somers
0a7c63e075 fusefs: Report the number of available ops in kevent(2)
Just like /dev/devctl, /dev/fuse will now report the number of operations
available for immediate read in the kevent.data field during kevent(2).

Sponsored by:	The FreeBSD Foundation
2019-05-12 15:27:18 +00:00
Alan Somers
3429092cd1 fusefs: support kqueue for /dev/fuse
/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
2019-05-11 22:58:25 +00:00
Alan Somers
7e0aac2408 fusefs: return ENOTCONN instead of EIO if the daemon dies suddenly
If the daemon dies, return ENOTCONN for all operations that have already
been sent to the daemon, as well as any new ones.

Sponsored by:	The FreeBSD Foundation
2019-05-10 16:41:33 +00:00
Alan Somers
d5024ba275 fusefs: minor optimization to interrupted fuse operations
If the daemon is known to ignore FUSE_INTERRUPT, then we may as well block
all signals while waiting for a response.

Sponsored by:	The FreeBSD Foundation
2019-05-10 16:31:51 +00:00
Alan Somers
61b0a927cb fusefs: use effective gid, not real gid, for FUSE operations
This is the gid used for stuff like setting the group of a newly created
file.

Reported by:	pjdfstest
Sponsored by:	The FreeBSD Foundation
2019-05-04 02:11:28 +00:00
Alan Somers
102c7ac083 fusefs: handle ENOSYS for FUSE_INTERRUPT
Though it's not documented, Linux will interpret a FUSE_INTERRUPT response
of ENOSYS as "the file system does not support FUSE_INTERRUPT".
Subsequently it will never send FUSE_INTERRUPT again to the same mount
point.  This change matches Linux's behavior.

PR:		346357
Sponsored by:	The FreeBSD Foundation
2019-04-24 17:30:50 +00:00
Alan Somers
ebbfe00ec2 fusefs: interruptibility improvements suggested by kib
* Block stop signals in fticket_wait_answer
* Hold ps_mtx while checking signal disposition
* style(9) changes

PR:		346357
Reported by:	kib
Sponsored by:	The FreeBSD Foundation
2019-04-24 15:54:18 +00:00
Alan Somers
419e7ff674 fusefs: rename the SDT probes from "fuse" to "fusefs"
This matches the new name of the kld.

Sponsored by:	The FreeBSD Foundation
2019-04-20 00:04:31 +00:00
Alan Somers
4423ae76ca fusefs: reap dead code
Sponsored by:	The FreeBSD Foundation
2019-04-19 23:04:07 +00:00
Alan Somers
268c28edbc fusefs: give priority to FUSE_INTERRUPT operations
When interrupting a FUSE operation, send the FUSE_INTERRUPT op to the daemon
ASAP, ahead of other unrelated operations.

PR:		236530
Sponsored by:	The FreeBSD Foundation
2019-04-19 21:50:23 +00:00
Alan Somers
3d070fdc76 fusefs: don't send FUSE_INTERRUPT for ops that are still in-kernel
If a pending FUSE operation hasn't yet been sent to the daemon, then there's
no reason to inform the daemon that it's been interrupted.  Instead, simply
remove it from the fuse message queue and set its status to EINTR or
ERESTART as appropriate.

PR:		346357
Sponsored by:	The FreeBSD Foundation
2019-04-19 15:05:32 +00:00
Alan Somers
a154214620 fusefs: improvements to interruptibility
* 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
2019-04-18 19:16:34 +00:00
Alan Somers
723c776829 fusefs: WIP making FUSE operations interruptible
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
2019-04-17 23:32:38 +00:00
Alan Somers
f067b60946 fusefs: implement VOP_ADVLOCK
PR:		234581
Sponsored by:	The FreeBSD Foundation
2019-04-12 23:22:27 +00:00
Alan Somers
8d013bec7a fusefs: fix some uninitialized memory references
This bug was long present, but was exacerbated by r345876.

The problem is that fiov_refresh was bzero()ing a buffer _before_ it
reallocated that buffer.  That's obviously the wrong order.  I fixed the
order in r345876, which exposed the main problem.  Previously, the first 160
bytes of the buffer were getting bzero()ed when it was first allocated in
fiov_init.  Subsequently, as that buffer got recycled between callers, the
portion used by the _previous_ caller was getting bzero()ed by the current
caller in fiov_refresh.  The problem was never visible simply because no
caller was trying to use more than 160 bytes.

Now the buffer gets properly bzero()ed both at initialization time and any
time it gets enlarged or reallocated.

Sponsored by:	The FreeBSD Foundation
2019-04-04 20:24:58 +00:00
Alan Somers
9a696dc6bb MFHead@r345880 2019-04-04 18:26:32 +00:00
Alan Somers
12292a99ac fusefs: correctly handle short writes
If a FUSE daemon returns FOPEN_DIRECT_IO when a file is opened, then it's
allowed to write less data than was requested during a FUSE_WRITE operation
on that file handle.  fusefs should simply return a short write to userland.

The old code attempted to resend the unsent data.  Not only was that
incorrect behavior, but it did it in an ineffective way, by attempting to
"rewind" the uio and uiomove the unsent data again.

This commit correctly handles short writes by returning directly to
userland if FOPEN_DIRECT_IO was set.  If it wasn't set (making the short
write technically a protocol violation), then we resend the unsent data.
But instead of rewinding the uio, just resend the data that's already in the
kernel.

That necessitated a few changes to fuse_ipc.c to reduce the amount of bzero
activity.  fusefs may be marginally faster as a result.

PR:		236381
Sponsored by:	The FreeBSD Foundation
2019-04-04 16:51:34 +00:00
Alan Somers
f220ef0b35 fix the GENERIC-NODEBUG build after r345675
Submitted by:	cy
Reported by:	cy, Michael Butler <imb@protected-networks.net>
MFC after:	2 weeks
X-MFC-With:	345675
2019-03-29 14:07:30 +00:00
Alan Somers
080518d810 fusefs: convert debug printfs into dtrace probes
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.

Also, de-inline fuse_internal_cache_attrs.  It's big enough to be a regular
function, and this way it gets a dtrace FBT probe.

This commit is a merge of r345304, r344914, r344703, and r344664 from
projects/fuse2.

Reviewed by:	cem
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19667
2019-03-29 02:13:06 +00:00
Alan Somers
f9856d0813 MFHead @345353 2019-03-20 23:32:37 +00:00
Alan Somers
123af6ec70 Rename fuse(4) to fusefs(4)
This makes it more consistent with other filesystems, which all end in "fs",
and more consistent with its mount helper, which is already named
"mount_fusefs".

Reviewed by:	cem, rgrimes
MFC after:	2 weeks
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D19649
2019-03-20 21:48:43 +00:00
Alan Somers
c02ccc7e44 Fix typos from r344664
Sponsored by:	The FreeBSD Foundation
2019-03-01 15:49:11 +00:00
Alan Somers
cf16949867 fuse(4): convert debug printfs into dtrace probes
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
2019-02-28 19:27:54 +00:00
Conrad Meyer
02295caf43 Fuse: whitespace and style(9) cleanup
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.
2019-02-20 02:49:26 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
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.
2017-11-20 19:43:44 +00:00
Fedor Uporov
04660064b8 Add extended attributes support to fuse kernel module.
Author:         kem
Reviewed by:    cem, pfg (mentor)
Approved by:    pfg (mentor)
MFC after:      2 weeks

Differential Revision: https://reviews.freebsd.org/D12485
2017-10-14 19:02:52 +00:00
Attilio Rao
4cff153b87 Rename s/DEBUG()/FS_DEBUG() and s/DEBUG2G()/FS_DEBUG2G() in order to
avoid a name clash in sparc64.

MFC after:	2 months
X-MFC:		r241519
2012-10-14 03:51:59 +00:00
Attilio Rao
5fe580195f Import a FreeBSD port of the FUSE Linux module.
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
2012-10-13 23:54:26 +00:00